atw - International Journal for Nuclear Power | 03.2021

nucmag.com 

2021 

3 

ISSN · 1431-5254 

32.50 € 

Small Modular Reactor 

Safety-in-Design 

and Perspectives 

Nuclear Power is Dead, 

Long Live Nuclear Energy! 

BREST-OD-300 – 

Demonstration of Natural 

Safety Technologies

Are you ready for what's coming? 

It took 10 years for the cryptocurrency market to reach 

1,000,000,000,000 Euro. It reached 2,000,000,000,000 Euro 

in only the last two months. Yet this asset class still only holds 

1 % of all global investment. 

We truly believe it's time to introduce 21 st century technology – 

Blockchain – to the world's best form of energy production: 

Nuclear Fission. 

And really Thorium Molten Salt Burner tech is the way to go – 

a clear winner with and EROI of 2000*: 

, With a 1T Euro SMR market predicted by 2030, meaning 

thousands of SMRs around the world, this is something 

to take notice of and efficient digitisation of the data is the 

only viable way to go. 

, With Honey Badger, we are first to market 

with a commercial solution. 

Join our cause to find out 

how you can be part of the future, today. 

Subscribe for our newsletter here: 

https://TheThoriumNetwork.com 

* https://www.ansto.gov.au/our-science/nuclear-fuel-cycle/advanced-nuclear-reactors/ 

evolution-of-molten-salt-reactors

atw Vol. 66 (2021) | Issue 3 ı May 

Towards New Reactors and 

Reactor Concepts 

Nuclear energy is often referred to as “dinosaur technology” in discussions in order to characterize it in advance, 

beyond a fair discussion. But even this is wrong, because the peaceful use of nuclear energy began about 70 years ago, 

in the early 1950s, and it is thus virtually as young as, for example, renewable photovoltaics. 

The first electricity from nuclear energy was generated in 

1948 in an experimental facility. At the Oak Ridge National 

Laboratory in the state of Tennessee in the USA, the X-10 

reactor was commissioned in 1943 as the world's second 

nuclear reactor after the Chicago Pile 1. From 1945, it 

served research purposes and was also the first reactor in 

the world to supply radioisotopes for medical use. The 

air-cooled, graphite-moderated reactor offered a wide 

range of possibilities for research but also technical 

applications. In 1948, a small steam generator was 

installed, the steam from which provided the drive for a 

model generator that lit a light bulb for the first time in the 

same year. 

For the first time, electricity from a power plant 

turbogenerator was supplied by the EBR-I fast reactor on 

20 December 1951; four light bulbs marked the way to 

further nuclear power generation. 

Because of the many technical options and combinations 

offered by nuclear fission, a wide variety of plant 

concepts were pursued in the 1960s and 1970s, including a 

broad range of applications. At an early stage, those 

involved and developers were thinking not only of direct 

power generation but also of district heating or the 

provision of high-temperature process heat, seawater 

desalination and chemical processes and energy storage – 

all highly topical subjects today, for which experience 

and historical documents from nuclear energy development 

can provide valuable references, foundations and 

elaborations. 

As is well known, the developments around the 

light water reactor technology have been commercially 

successful until today, also because they could fall back on 

manifold experiences of conventional power and energy 

generation and provided a realizable potential with regard 

to the further increasing plant capacities demanded at that 

time. 

However, in these successful decades since the 1960s – 

nuclear energy continues to be one of the most important 

low-emission energy sources alongside hydropower, with 

a share of around 11 % – other reactor concepts have never 

completely lost their importance in research and development. 

Comprehensive concept studies, such as the work of 

the Generation IV International Forum (GIF) in the context 

of "Generation IV," were essential in this regard. In 2002, 

GIF published the so-called Technology Roadmap, which 

describes six reactor types that are considered suitable for 

achieving or meeting the development goals of safety, 

sustainability and economic efficiency. But the work on 

high-temperature reactor concepts or fast reactors in 

China, India and Russia also underlines the continuity, up 

to the construction and operation of real pilot plants. 

When it comes to concepts for the future, a broad 

spectrum of developments is on the agenda today. The 

change in overall power generation, i.e. initially essentially 

characterized by more renewable capacities with unsteady 

and unpredictable power feed-in, also requires other 

solutions for the indispensable “conventional” generation. 

Ultimately, power plants or storage solutions must ensure 

grid stability and security of supply. 

Nuclear energy can advantageously cover a broad 

power spectrum, if only because of its scalability. What is 

new is how the U.S. Department of Energy classifies future 

nuclear power plants according to their output into: 

p Microreactors from 1 to 20 MWe(lectric) 

p Small Modular Reactors – SMR from 20 to 300 MWe 

and 

p High-power reactors from 300 to 1,000 MWe. 

These reactors would cover the currently foreseeable 

demand for new and additional generation capacities in 

the best possible way. The “microreactors” are newly 

classified. Thus, their small footprint and an expected 

construction time of no more than 24 months – DOE 

expects 54 months for SMRs – make them appear suitable 

for combination with high-capacity renewable generation 

parks, where a source as close to site as possible is needed 

to balance volatility. 

However, new nuclear power plant developments also 

require an appropriate regulatory environment and 

infrastructure. Historical experience shows that quasisimultaneous 

development of rules and regulations for 

large-scale projects can lead to noticeable delays with their 

planning, design, and construction. A coordinated and 

systematic approach is needed here. The fact that a suitable 

regulatory environment and a safe infrastructure for new 

nuclear power plant projects can be set up and implemented 

in a targeted and speedy manner is impressively 

demonstrated by the four new nuclear power plants built 

in the United Arab Emirates. Within just a decade from the 

final construction decision until now, the commercial 

commissioning of the first of four 1,400 MW nuclear power 

plant units at the Barakah site, the necessary reliable 

environment has been established. Also, worldwide, the 

IAEA – International Atomic Energy Agency – today 

supports 30 countries in building infrastructure for the 

desired entry into peaceful use of nuclear energy – as a 

sustainable, low-emission energy source with economic 

and consumer-oriented generation. 

Christopher Weßelmann 

– Editor in Chief – 

3 

EDITORIAL 

Editorial 

Towards New Reactors and Reactor Concepts


Contents 

4 

CONTENTS 

Issue 3 

2021 

May 

Editorial 

Towards New Reactors and Reactor Concepts . . . . . . . . . . . . . . 3 

Inside Nuclear with NucNet 

Lessons Learned 

From the March 2011 Fukushima-Daiichi Nuclear Accident . . . . . 6 

Calendar 8 

Feature | Research and Innovation 

Small Modular Reactor Safety-in-Design and Perspectives . . . . . . .9 

Akira Tokuhiro, Chireuding Zeliang and Yi Mi 

Cover: 

Site layout for the SMR nuclear site complex 

by MOLTEX Energy. A feasibility report for Canada 

with the MOLTEX concept under review has just been 

published. 

Contents: 

2020-year-in review – 

The NuScale Energy Exploration Center, 

Copyright NuScale 

Did you know? 17 

Q&A with the Ministry of Natural Resources Canada 

The Nuclear Innovation Policy of Canada . . . . . . . . . . . . . . . . 18 

Interview with John Gorman 

“I am Personally Very Excited About Canadas’s Positioning 

as a Tier One Nuclear Power and also as a First Mover 

in Small Modular Reactors“ . . . . . . . . . . . . . . . . . . . . . . . 21 

Serial | Major Trends in Energy Policy and Nuclear Power 

Nuclear Power is Dead, Long Live Nuclear Energy! . . . . . . . . . . 25 

Simon Wakter 

Energy Policy, Economy and Law 

Europe on the Road to a Major Disaster . . . . . . . . . . . . . . . . 29 

Herbert Saurugg 

A Role for Nuclear in the Future Dutch Energy Mix . . . . . . . . . 35 

Bojan Tomic and Mario van der Borst 

Operation and New Build 

BREST-OD-300 – Demonstration of Natural Safety Technologies . 41 

Vadim Lemehov and Valeriy Rachkov 

At a Glance 

Nuclear Innovation Alliance (NIA) . . . . . . . . . . . . . . . . . . . . 46 

Environment and Safety 

Safety-related Residual Heat Removal Chains of German 

Technology Pressure Water Reactors (Light and Heavy Water) . . 48 

Franz Stuhlmüller and Rafael Macián-Juan 

IAEA Approach to Review the Applicability of the Safety 

Standards to Small Modular Reactors . . . . . . . . . . . . . . . . . . 56 

Paula Calle Vives, Kristine Madden and Vesselina Ranguelova 

Research and Innovation 

A Zero-power Facility as a Multi-fold Opportunity to Support 

Quick Progress in Innovative Reactor Development . . . . . . . . . 59 

Bruno Merk, Dzianis Litskevich, Anna Detkina, Greg Cartland-Glover, Seddon Atknison and Mark Bankhead 

The Thorium Network – An Introduction to Blockchain for SMRs . 65 

Dian Kemp, Hulmo Christiaansen, Yvette Kemp and Jeremiah E. Josey 

Kazatomprom’s Digital Transformation Projects . . . . . . . . . . . 68 

Aliya Akzholova 

Studies on Performance and Degradation Stability 

of Chemically Degraded Nuclear Graded Ion Exchange 

Materials by Application of Radio Analytical Technique . . . . . . 71 

Pravin Singare 

News 78 

Nuclear Today 

As Reactor Technologies Advance, 

Nuclear Will Still Need its Environmental Champions . . . . . . . . 82 

Imprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 

Contents


5 

Feature 


9 Small Modular Reactor Safety-in-Design 

and Perspectives 

CONTENTS 


Interview with John Gorman 

21 “I am Personally Very Excited About Canadas’s Positioning 

as a Tier One Nuclear Power and also as a First Mover 

in Small Modular Reactors“ 


25 Nuclear Power is Dead, Long Live Nuclear Energy! 

Simon Wakter 


29 Europe on the Road to a Major Disaster 



41 BREST-OD-300 – Demonstration of Natural Safety Technologies 



56 IAEA Approach to Review the Applicability of the Safety Standards 

to Small Modular Reactors 


Contents


6 

INSIDE NUCLEAR WITH NUCNET 

Lessons Learned From the March 2011 

Fukushima-Daiichi Nuclear Accident 

The official Japanese report into the accident 10 years ago pointed to ‘a multitude of errors and 

willful negligence’, but what steps have been taken to prevent a repeat? 

Although triggered by a cataclysmic earthquake and 

tsunami, the subsequent accident at the Fukushima-Daiichi 

nuclear power station 10 years ago cannot be regarded as a 

natural disaster. 

It was, the Fukushima Nuclear Accident Independent 

Investigation Commission concluded in its official report, 1 a 

profoundly manmade disaster – one that could and should 

have been foreseen and prevented. And its effects could 

have been mitigated by a more effective human response. 

Kiyoshi Kurokawa, chairman of the commission, was 

blunt in his assessment of the root causes, pointing to a 

multitude of errors and willful negligence that left the 

Fukushima-Daiichi facility unprepared for the events of 

11 March 2011. There were “serious deficiencies” in the 

response to the accident by plant owner and operator Tokyo 

Electric Power Company, regulators and the government. 

Mr Kurokawa said what the commission’s report could 

not fully convey – especially to a global audience – was the 

mindset that supported the negligence behind this disaster. 

“What must be admitted – very painfully – is that this 

was a disaster ‘Made in Japan’, he said. “Its fundamental 

causes were to be found in the ingrained conventions of 

Japanese culture: our reflexive obedience; our reluctance 

to question authority; our devotion to ‘sticking with the 

programme’; our groupism; and our insularity.” 

The report pointed to organisational problems within 

Tepco. Had there been a higher level of knowledge, 

training, and equipment inspection related to severe 

accidents, and had there been specific instructions given to 

the onsite workers concerning the state of emergency, a 

more effective accident response would have been possible. 

“Neither [Tepco or the regulators] had taken steps to 

put preventive measures in place,” the report concluded. 

“It was this lack of preparation that led to the severity of 

this accident.” 

The direct causes of the accident were all foreseeable. 

The power station was incapable of withstanding the earthquake 

and tsunami that hit on that day. The operator, Tokyo 

Electric Power Company (Tepco), the regulatory bodies (the 

Nuclear and Industrial Safety Agency and the Nuclear Safety 

Commission) and the government body promoting the 

nuclear power industry (the ministry of economy, trade and 

industry, or METI), all failed to correctly develop the most 

basic safety requirements – such as assessing the probability 

of damage, preparing for containing collateral damage from 

such a disaster, and developing evacuation plans for the 

public in the case of a serious radiation release. 

As early as 1981, NISA had required that nuclear 

operators assess the anti-seismic safety of their sites 

according to new guidelines – the so-called “anti-seismic 

backcheck.” 

In March 2008, Tepco submitted an interim anti- seismic 

backcheck report on Unit 5 of Fukushima-Daiichi, saying 

the unit was safe. 

In 2009, NISA accepted the contents of the interim 

report, even though the scope of the assessment included 

the reactor building and only seven of many other 

important safety installations and equipment. 

In June 2009, similar reports for Units 1 to 4 and 6 were 

submitted, but these were similarly limited. 

The official deadline for the backchecks was June 2009, 

but according to the commission, Tepco made the decision 

“internally and unilaterally” to reschedule the deadline to 

January 2016. 

Since 2006, the regulators and Tepco had also been 

aware of the risk that a total outage of electricity at the 

Fukushima Daiichi plant might occur if a tsunami were to 

reach the level of the site. They were also aware of the risk 

of reactor core damage from the loss of seawater pumps in 

the case of a tsunami larger than assumed in the Japan 

Society of Civil Engineers estimation. NISA knew that 

Tepco had not prepared any measures to lessen or eliminate 

the risk, but failed to provide specific instructions to 

remedy the situation. 

The report’s verdict on Tepco and the regulators was 

damning. “They either intentionally postponed putting 

safety measures in place, or made decisions based on their 

organisation’s self-interest – not in the interest of public 

safety.” 

An IAEA report 2 echoed these findings. It said a major 

factor that contributed to the accident was the widespread 

assumption in Japan that its nuclear power plants 

were so safe that an accident of this magnitude was 

simply unthinkable. This assumption was accepted by 

nuclear plant operators and was not challenged by 

regulators or by the government. As a result, Japan was not 

sufficiently prepared for a severe nuclear accident in 

March 2011. 

“The Fukushima-Daiichi accident exposed certain 

weaknesses in Japan’s regulatory framework,” the IAEA 

said. “Responsibilities were divided among a number of 

bodies, and it was not always clear where authority lay.” 

The Response In Japan 

Japan moved quickly to resolve serious problems around 

nuclear regulation, safety and accident readiness. 

The Nuclear Regulatory Authority was formed on 

19 September 2012 from the Nuclear Safety Commission 

(NSC), which came under the authority of the cabinet, and 

the Nuclear and Industry Safety Agency (NISA), which was 

under METI. The problem lay in the fact that METI was 

also responsible for the promotion of nuclear power, 

leading to accusations of a serous conflict of interest. The 

NRA was established as an independent entity under the 

environment ministry. 

According to legislation establishing the NRA, new 

nuclear safety rules were to be completed within 

10 months. The NRA’s first chairman, Shunichi Tanaka, 

1 https://www.nirs.org/wp-content/uploads/fukushima/naiic_report.pdf 

2 https://www.iaea.org/sites/default/files/fr-brochure.pdf 


Lessons Learned From the March 2011 Fukushima-Daiichi Nuclear Accident


said that the authority would undertake a radical review of 

existing safety standards. 

In January 2013 the NRA presented a draft outline of 

new safety standards 3 for nuclear power plants, including 

countermeasures against severe accidents and criteria for 

evacuating areas around plants during an emergency. 

The standards were approved in June 2013 4 and became 

effective on 8 July 2013. The NRA began accepting 

applications for reactor restarts. At this point only two of 

Japan’s 42 commercial reactors, Ohi-3 and Ohi-4, had 

restarted since the accident. 

The standards consisted of severe accident measures 

based on the accident at Fukushima-Daiichi, together with 

design standards and requirements in each area of nuclear 

plant safety. 

Measures included a requirement to outfit plants with 

backup control rooms away from reactor buildings, install 

new pressure vents capable of filtering out radioactive 

gasses, and reinforce protective structures. 

Operators deployed movable alternative equipment 

such as power supply vehicles so that plants could be 

operated safely for at least seven days without outside help. 

One of the severe accident measures was a requirement 

to build a so-called “specific safety facility” on nuclear 

plant sites, on the assumption of core damage in a reactor, 

with terrorism a possible cause. Terrorism would include 

an intentional aircraft strike. 

The safety facility had to be situated 100 metres or more 

from the reactor building, so it would not be destroyed in 

the same event. A secondary control room was required 

within the safety facility. 

Mr Tanaka said the new rules represented “the 

beginning of real [nuclear] regulation in Japan”. 

The IAEA said Japan has reformed its regulatory system 

to better meet international standards. Regulators have 

clearer responsibilities and greater authority. The new 

regulatory framework has been reviewed by an IAEA peer 

review mission. Emergency preparedness and response arrangements 

have also been strengthened, the agency said. 

Japan’s Nuclear Status 

Japan has 62 nuclear power units, but shut down all 42 

that were operating at the time after Fukushima-Daiichi. 

Thirty-three units have a licence to operate, although 

before units return to service they need to meet the NRA’s 

new safety standards. 

Nine units have been returned to service, but five of 

those are offline again for regular maintenance or 

upgrades. The four reactors that are online are Sendai-1, 

Sendai-2, Genkai-3 and Ohi-4. 

Before the Fukushima-Daiichi accident Japan’s nuclear 

fleet generated about 30 % of the country’s electricity. 

According to the International Atomic Energy Agency that 

figure was about 7.5 % in 2019. 

Governments with established nuclear-energy 

programmes responded in part by conducting safety 

checks, including comprehensive “stress tests” that 

scrutinised a facility’s ability to withstand everything from 

an earthquake and tsunami to a terrorist assault. 

Additional backup sources of electrical power and 

supplies of water have been installed, and protection 

against extreme external events strengthened. In some 

cases, organisational and regulatory systems have been 

reformed. 

Safety reassessments concluded that facilities examined 

offer a safety level that is sufficient, and no immediate 

shutdown was required. 

The IAEA emphasises that nuclear safety remains the 

responsibility of an individual country, but says nuclear 

accidents can transcend borders and the Fukushima- 

Daiichi accident “underlined the importance of international 

cooperation”. 

In Europe, all nuclear power plants in the EU underwent 

stress tests and peer reviews in 2011 and 2012. Many 

other countries and territories also conducted comprehensive 

nuclear risk and safety assessments, based on 

the EU stress-test model. These include Switzerland and 

Ukraine (both of which fully participated in the EU stress 

tests), Armenia, Turkey, Russia, Taiwan, Japan, South 

Korea, South Africa and Brazil. 

In China, which had aspirations to build up to 100 new 

nuclear units by 2030, plans were put on hold. Premier 

Wen Jiabao announced the suspension of the approval of 

new nuclear power projects and called for a com prehensive 

safety assessment of Chinese nuclear power facilities. 

Beijing ultimately decided to lift the moratorium on 

construction of new nuclear power plants in October 2012. 

The state council said safety investigations had shown that 

“nuclear security is guaranteed in China.” 

In the US, the Nuclear Regulatory Commission ordered 

in March 2012 that nuclear power plants meet specific 

deadlines for safety checks and upgrades. 7 

The checks 

included maintaining key safety functions even if installed 

electricity sources fail; installing additional equipment to 

monitor spent fuel pool water levels; and installing or 

improving systems to safely vent pressure during an 

accident. The NRC also asked all US plants for information 

on comprehensive earthquake and flooding hazard 

analyses. 

Author 

David Dalton 

NucNet – 

The Independent Global Nuclear News Agency 

Bruxelles, Belgium 

www.nucnet.org 

INSIDE NUCLEAR WITH NUCNET 7 

The International Response 

Three months after the accident, the International Atomic 

Energy Agency hosted a ministerial conference on nuclear 

safety. This paved the way for the unanimous endorsement 

of an IAEA action plan 5 

that has led to international 

collaboration toward strengthening global nuclear safety. 6 

3 https://www.nucnet.org/news/japan-s-regulator-unveils-proposed-new-safety-measures 

4 https://www.nucnet.org/news/japan-s-regulator-approves-new-safety-guidelines 

5 https://www.iaea.org/topics/nuclear-safety-action-plan 

6 https://www.iaea.org/newscenter/news/four-years-of-progress-action-plan-on-nuclear-safety 

7 https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/japan-events.html 


Lessons Learned From the March 2011 Fukushima-Daiichi Nuclear Accident


8 

CALENDAR 

Calendar 

2021 

Online Conference 04.05.2021 

2021 KTG Annual Meeting. Berlin, Germany, KTG, 

www.ktg.org 

Online Conference 10.05. – 15.05.2021 

FEC 2020 – 28 th IAEA Fusion Energy Conference. 

Nice, France, IAEA, www.iaea.org 

18.05. – 20.05.2021 

Power Uzbekistan 2021 – 15 th Anniversary 

International Exhibition on Energy. 

Tashkent, Uzbekistan, Iteca Exhibitions, 

www.power-uzbekistan.uz 


ICONE 28 – 28 th International Conference on 

Nuclear Engineering. Nuclear Energy the Future 

Zero Carbon Power. ASME, https://event.asme.org 

25.08. – 27.08.2021 

KONTEC 2021 – 15 th International Symposium 

“Conditioning of Radioactive Operational & 

Decommissioning Wastes”. Dresden, Germany, 

atm, www.kontec-symposium.de 

25.08. – 03.09.2021 

The Frédéric Joliot/Otto Hahn Summer School 

on Nuclear Reactors “Physics, Fuels and Systems”. 

Aix-en-Provence, France, CEA & KIT, www.fjohss.eu 

29.08. - 03.09.2021 

PSA 2021 – International Topical Meeting on 

Probabilistic Safety Assessment and Analysis. 

ANS, Columbus, OH, USA, www.psa.ans.org 

Postponed to 24.10. – 28.10.2021 

TopFuel 2021. Santander, Spain, ENS, 

https://www.euronuclear.org/topfuel2021 

26.10. – 28.10.2021 

VGB Conference Chemistry. Ulm, Germany, VGB 

PowerTech, www.vgb.org 

01.11. – 12.11.2021 

COP26 – UN Climate Change Conference. 

Glascow, Scotland, www.ukcop26.org 

Postponed to 30.11. – 02.12.2021 

Enlit (former European Utility Week and 

POWERGEN Europe). Milano, Italy, 

www.enlit-europe.com 

30.11. – 02.12.2021 

WNE2021 – World Nuclear Exhibition. Paris, 

France, Gifen, www.world-nuclear-exhibition.com 

Postponed to 30.08. – 03.09.2021 

International Conference on Operational Safety 

of Nuclear Power Plants. Beijing, China, IAEA, 

www.iaea.org 

2022 


Small Modular Reactors (SMR). Prospero, 

www.prosperoevents.com 

Cancelled due to COVID 30.05. – 05.06.2021 

BEPU2020 – Best Estimate Plus Uncertainty 

International Conference, Giardini Naxos. 

Sicily, Italy, NINE, www.nineeng.com 


Management systems for a sustainable nuclear 

supply chain. Helsinki, Finland, Foratom, 

https://events.foratom.org/mstf2021 

Hybrid Conference 08.09. – 10.09.2021 

3 rd International Conference on Concrete 

Sustainability. Prague, Czech Republic, fib, 

www.fibiccs.org 

08.09. – 10.09.2021 

World Nuclear Association Symposium 2021. 

London, UK, WNA, www.wna-symposium.org 

Postponed to 28.02. – 04.03.2022 

20 th WCNDT – World Conference on 

Non-Destructive Testing. Incheon, Korea, 

The Korean Society of Nondestructive Testing, 

www.wcndt2020.com 

06.03. – 11.03.2022 

NURETH19 – 19 th International Topical Meeting 

on Nuclear Reactor Thermal Hydraulics. SCK·CEN, 

Brussels, Belgium, www.events.sckcen.be 

22.09. – 23.09.2021 

VGB Congress 100 PLUS. Essen, Germany, VGB 

PowerTech, www.vgb.org 


Nuclear Power Plants IV. Expo & VIII. Summit 

(NPPES). Istanbul, Turkey, INPPES Expo, 

www.nuclearpowerplantsexpo.com 


HTR2021 – 10 th International Conference 

on High Temperature Reactor Technology. 

Yogyakarta, Indonesia, Indonesian Nuclear Society, 

www.htr2020.org 


Nuclear Energy Assembly. NEI, 

www.nei.org 


2021 ANS Annual Meeting. ANS, www.ans.org 

26.09. – 30.09.2021 

RRFM 2021 – European Research Reactor 

Conference. ENS, Helsinki, Finland, 

www.euronuclear.org 

27.09. – 30.09.2021 

European Nuclear Young Generation Forum 

(ENYGF). Tarragona, Spain, ENYGF, www.enygf.org 

27.09. – 01.10.2021 

NPC 2021 International Conference on Nuclear 

Plant Chemistry. Antibes, France, SFEN Société 

Française d’Energie Nucléaire, 

www.sfen-npc2021.org 

04.10. – 05.10.2021 

AtomExpo 2021. Sochi, Russia, Rosatom, 

http://2021.atomexpo.ru/en 

29.03. – 30.03.2022 

KERNTECHNIK 2022. 

Leipzig, Germany, KernD and KTG, 

www.kerntechnik.com 

04.04. – 08.04.2022 

International Conference on Geological 

Repositories. Helsinki, Finland, EURAD, 

www.ejp-eurad.eu 

Postponed to Spring 2022 

4 th CORDEL Regional Workshop – Harmonization 

to support the operation and new build of NPPs 

including SMR. Lyon, France, World Nuclear 

Association, https://events.foratom.org 


Maintenance in Power Plants 2021. 

VGB PowerTech e.V., www.vgb.org 


POWER 2021. ASME, www.event.asme.org 

Online Conference 03.08.-04.08. 

and 10.08.-11.08.2021 

International Uranium Digital Conference 2021. 

AusIMM, www.ausimm.com 

Postponed – final date and location 

to be determined 

ICEM 2021 – International Conference on 

Environmental Remediation and Radioactive 

Waste Management. ANS, www.asme.org 

16.10. – 20.10.2021 

ICAPP 2021 – International Conference on 

Advances in Nuclear Power Plants. Khalifa 

University, Abu Dhabi, United Arab Emirates, 

www.icapp2020.org 

Postponed to 04.05. – 06.05.2022 

NUWCEM 2022 – International Symposium on 

Cement-Based Materials for Nuclear Wastes. 

Avignon, France, SFEN, www.sfen-nuwcem2021.org 

This is not a full list and may be subject to change. 

Calendar


Small Modular Reactor 

Safety-in-Design and Perspectives 


Across the public, nuclear power and global energy sectors, there are various degrees of interest in next and 

near-generation micro- to small, modular reactors (MMR, SMR) 1 . The ongoing interests, here defined in terms of 

commercial and national technology developments, policy documents (roadmaps, action plans, etc.), various levels 

and means of “investments”, are intended to support and facilitate development of select advanced reactor concepts 

and demonstration units. The current portfolio of SMRs and MMRs is relative to the current, global fleet; mostly larger 

scale nuclear plants (Generation III and III+ designs) currently under construction and/or operating. These legacy 

designs largely meet the electricity demand in nations with robust socio-economic development rates. Both the 

operating plants and those in various stages of development are included in a “pan-global, nuclear portfolio”, touted (in 

the “24/7/365” social media) to address and mitigate the negative impacts of climate change. While there are reasons 

to “worry” about the lack of foresight, preventative preparedness and response to address the cliff-edge impacts of climate 

change, the goal here is not to argue climate change nor policies/developments in national commitments to a 

lower or net-zero carbon economies of scale. If anything, climate change can be construed as human society’s inability 

to exercise a paradigm shift – in effect, a linear extrapolation from 150+ years of industrialization based on fossil fuels 

and release of effluents without consequences. Along the way, we forgot to ask what can happen and how can it happen. 

The consequences are here and imminent (“urgent”), as expressed by climate change leaders, Greta Thunberg, and 

others. Nature is suffering in our age of our Anthropocene. 

With this in mind, the article here will review a number of 

ongoing micro- to small, modular reactors concepts, but 

from the perspective of engineering and design development 

so that the design is completed. While engineered 

and designed features hold much interest to those with 

engineering and R&D backgrounds, one might argue that 

if nuclear energy is to serve in transition and/or as a 

solution to aspirational economies of scale that mitigate 

and reduce the negative impacts of climate change, nuclear 

reactor designs need to be complete, prudently financed 

and “constructable”, because ultimately they serve to 

generate electricity that the public expects and demands. 

Some 70 years ago in nuclear history, then U.S. President 

Dwight Eisenhower appeared at the United Nations (1953) 

and spoke on, “Atoms for Peace”. Subsequently, in the then 

short list of post-WWII developed and developing nations, 

there was rapid development, and selection process of 

Generation I and II nuclear concepts. Many of these are 

part of the 440 or so nuclear power plants operating today. 

1 Designs, Legacy and Processes 

A few words about the design and engineering process of 

new/advanced reactor concepts is in order. Perhaps owing 

to the lead author’s educational legacy, it is not something 

that I remember explicitly learning during my nuclear 

engineering education. That said, there are established 

processes within nuclear vendors (manufacturers) that 

remain proprietary. These practices do not necessarily 

make it into university classrooms. My observation has 

been that seasoned professionals from the nuclear sector 

do not transition late in their career, to university nuclear 

engineering programs/classrooms. There can thus be a 

knowledge transfer gap, from the reactor vendor to the 

classroom. 

The article here on advanced reactor concepts and 

SMRs/MMRs, is based on the assumption that completing 

the design is of utmost importance, and that the design 

process takes time and requires sufficient and sustained 

funding because the key high-level task is, iterative 

system design. That is, engineering system design, wherein 

systems and subsystems are coupled, require iterative 

design optimization. This is certainly the case in nuclear 

reactor design. 

So, we note that SMRs, like many nuclear reactors are 

generally designed from the reactor core, outward in terms 

of various essential and supporting systems; that is, the 

primary, secondary systems and beyond. In fact, one could 

say for SMRs, the design regions of interest extend all the 

way to the emergency planning zone (EPZ), since in 

principle, a SMR’s EPZ should be related to, “very 

small probability (keep reading) but a high consequence”, 

hypothetical accidents. One can say that increasingly 

Generation IV (or advanced) reactor concepts are expected 

to have very small hypothetical probability with respect to 

design basis and beyond design basis accidents (DBA, 

BDBA), and features that substantiate means to address 

Fukushima (Daichi) type situations. In fact, the design 

itself is expected to have a number of safety-in-design 

features so that the commonly cited metrics such as, “core 

damage frequency” (CDF) and/or “early release frequency” 

(ERF), are typically, smaller than 1E-06 2 , if not 1E-08. (We 

note here that probabilities – less than say, 1E-09, 1E-10 or 

smaller may not hold regulatory meaning or significance.) 

Further, other than these small probabilities, observance 

or adherence to safety-in-design philosophies/principles 

as described in INSAG-10 [14], and “goodness” in design 

such that no human intervention is required for durations 

of time beyond “event” initiation (i.e. first 24, 48, 72 hours, 

etc.), detailed information on accident progression/ 

evolution, may appear as aspirational or embedded in the 

design features and functions, without open access to the 

technical details. Open access of detailed technical 

information may not be possible; thus, it is not current 

practice. 

With the above design engineering process and metrics 

in mind, let us look at the micro- to small modular reactor 

9 

FEATURE | RESEARCH AND INNOVATION 

1 The term, SMR, is used to be inclusive of Small and Micro Modular Reactor concepts and designs. 

2 This notation is used instead of a superscript that may appear visibly small (1 x 10 -6 ). 

Feature 

Small Modular Reactor Safety-in-Design and Perspectives ı Akira Tokuhiro, Chireuding Zeliang and Yi Mi


FEATURE | RESEARCH AND INNOVATION 10 

concepts currently under various states of development. 

We note that since a number of overview articles on SMR/ 

MMR reactor concepts exist, this article is not intended to 

be such. Instead we thought to reveal some of the not so 

obvious aspects of safety-in-design, that various advanced 

reactor designers may adopt to varying degrees. First for 

brevity and utility, we cite some of the key documents 

below as a starting point into the various aspects 

surrounding SMRs as follows: 

p On safety-in-design, references [1, 7, 14, 17(US only), 

23, 24, 30] 

p On licensing and regulatory aspects of SMRs, reference 

[3, 15, 19, 22] 

p Overview and advances of SMR, reference [2, 6, 9, 16, 

31, 33, 36, 40] 

p Specifically passive safety systems within safety-indesign, 

references [8, 20, 32] 

p Nuscale, SMART, IRIS, CAREM, ESBWR, AP1000 

specific starting documents, reference [10, 11, 12, 13, 

21 (NuScale EPZ), 28, 29]. Note that the ESBWR and 

AP1000 are Generation III/III+, large-scale plant 

designs from which lessons learned are realized in SMR 

designs. 

p General principles in nuclear design and economics, 

references [4 (economics),18, 25, 26] 

2 Back to the future with nuclear energy? 

In a manner similar to many early nuclear reactor 

concepts in the late 1950s, early 1960s, there are many 

micro- to small, modular reactor concepts. However, with 

approximately 60 years of complete design experience, 

operational experience, lessons learned from three major 

severe accidents, (along with other recorded events), 

unrestrained cost increases, regulatory compliance burdens, 

anti-nuclear sentiments and advances in computer- based 

engineering, recent advanced reactor designs hold consensus 

expectations in safety, nonproliferation and 

economics. It goes without much declaration that nuclear 

energy is often questioned and compared to other forms of 

energy (including renewable energy sources) and as a 

matter of regional to national energy policy. In recent years, 

public acceptance of any risk-inherent technology, processes, 

production and consumption – a composite portfolio 

of social license, advocacy and questionable objectivity 

issues, are fiercely fought with fervent banter in social 

media domains. Everyone has an opinion. 

Nuclear energy and new micro- to small, modular 

reactor concepts are not benign from socio-technical 

scrutiny, most recently in the global debate on whether 

nuclear energy is a partial to full solution to counter the 

increasingly emerging evidence on the negative impacts of 

climate change. 

2.1 The micro- to small, modular reactor 

concepts 

Nuclear reactors are traditionally classified in terms of the 

following technical features. These features are high-level 

decisions made by its originators. They are: 1) neutron 

spectrum, 2) related type of neutron moderation, 3) type 

of coolant, 4) fuel type and core configuration. We will use 

the same approach for consistency. We note Hussein [40] 

review that used an expanded classification based on 

200+ cited references. 

We limit our coverage below to SMR design concepts 

of thermal power (output) magnitude that feature conventional 

or unique energy conversion system design, utilizing 

a liquid-based energy transport system from a defined core 

configuration. The core and energy transport system 

should fulfill the basic functions as follows: startup (to 

criticality), (transition to) steady-state operation at a 

targeted power, transition up or down from a given power 

setting to another, intended shutdown, emergency shutdown 

and post-shutdown decay heat energy removal (to 

cold shutdown state). 

In this regard, micro-modular reactor concepts (MMR) 

are even simpler in design than many SMR concepts 

because the thermal power output is approximately an 

order of magnitude smaller than SMR (i.e. ~O (5 MWth) 

per reactor core vs. ~O (50 MWth)) per reactor core] and 

as such, the corresponding means of reactivity control are 

reduced accordingly. With respect to MMR safety-indesign, 

post-shutdown energy removal mechanisms are 

predominantly passive such that air or a large volume of 

water, serves as the ultimate heat sink for decay heat. 

Energy conversion systems are correspondingly modular 

in design and may feature reduced coupling to reactor core 

control (and thus operations) such that the sole output is 

electricity and/or thermal energy. With such simple design 

and limited functions, the thermal-hydraulic “parameter 

space” is correspondingly small, such that conventional 

means of control (analog and/or digital) can be used for 

monitoring, prognostics and diagnostics. The 2020 release 

of the IAEA “book” on SMRs/MMRs contains 6 MMR concepts. 

A concise, descriptive summary of the announced 

MMR concepts is given below. 

1) Energy Well (Rez, Czech Republic) – is a high 

temperature (core inlet, 650 °C; outlet, 700 °C) molten 

salt FLiBe cooled and moderated, with targeted thermal 

and electrical power output, 20MWt/8 MWe. The once 

through core design features 15 % enriched TRISO fuel 

and operational reactivity control via Y-shaped control 

rods. Energy conversion is a 3-loop (FLiBe, NaBF 4 , 

supercritical CO 2 ) design so as to avail pro duction of 

electricity, hydrogen and energy storage, juxtaposed 

against the Czech national energy portfolio. Common 

to many national nuclear conceptual design engineering 

studies (here at nuclear R&D centre, Rez), while 

development details may be ongoing, a path toward 

commercialized deployment is unknown. 

2) MoveLuX (Toshiba, Japan) – is a sodium heat-pipe 

cooled and calcium hydride moderated, natural 

convection (air-based primary circuit) driven MMR 

with thermal/electrical power output, targeted at 

10 MWt/3-4 MWe. The core design uses uranium 

silicide (U 3 Si 2 ) fuel housed in hexagonal “cans” with 

lithium expansion system reactivity control. With a 

sodium heat pipe based higher temperature conversion 

system coupled to helium gas, electricity and hydrogen 

production are possible, as well as a fuel cycle adapted 

to the national fuel cycle practice. This MMR concept is 

a Toshiba internal conceptual design study. 

3) U-Battery (Urenco, UK) – is a high-temperature, helium 

gas-cooled, graphite-moderated MMR with targeted 

thermal/electrical output, 10 MWt/4 MWe. The core 

design uses TRISO fuel, enriched up to 20 %, in 

hexagonal blocks with control rods, fixed burnable 

poisons and shut-down absorber spheres. A 5-year full 

power year and 30-year design life are targeted. Energy 

conversion is via indirect secondary nitrogen circuit 

with applications both for heat applications or closed 

gas-turbine technology (no combustion stage). 

Regulatory approval of its detailed design and 

commercialization partners have been announced by 

its developer, URENCO – UK. 

Feature 



4) AURORA – (Oklo, USA) – with a targeted thermal/ 

electric power output, 4 MWt/1.5 MWe, this compact, 

liquid-metal cooled fast reactor MMR using metal fuel, 

a 20-year refueling cyle, Oklo has applied for a USNRC 

combined license application. The plant features low 

power output, low power density and low decay heat 

output, and correspondingly has low fuel burnup, small 

fuel inventory, simplicity in energy removal by inherent 

and passive means, and overall takes advantage of 

thermal capacity via use of higher con ductivity material 

selection. Oklo has an existing agreement to access 

the Idaho National Lab site and some aspects of their 

technology know-how under a partnership agreement. 

5) eVinci Micro Reactor (Westinghouse, USA) – this 

conceptual design MMR with a targeted thermal/ 

electrical power output, 7-12 MWt/2-3.5 MWe, uses 

(sodium) heat pipes and metal hydride moderator in a 

stand-alone, transportable reactor and energy conversion 

system unit. Instrumentation and controls are 

provided via a separate, integrated (second) unit. The 

core is based on TRISO or similarly encapsulated fuel, 

in a monolithic core with reactivity control realized via 

ex-core (moving) control drums. Onsite refueling or 

whole reactor replacement are envisioned. Energy 

conversion is via open-air Brayton and single shaft gas 

turbomachinery. The core is designed with negative 

reactivity, and decay heat removal is via intended 

conduction and natural convective heat dissipation to 

air. The design integrates many elements and simplifications 

based on lessons learned by Westinghouse in 

overall plant “island” design. The design concept is 

under Vendor Design Review, Canadian Nuclear Safety 

Commission (CNSC), and preliminary discussions with 

the USNRC. 

6) MMR (Ultra Safe Nuclear, USA) – this MMR with a 

( Canadian) national laboratory site partnership 

permit, has a targeted thermal/electrical power ouput, 

15 MWt/greater than 5MWe. This MMR is a hightemperature, 

(helium) gas-cooled, graphite- moderated, 

solar salt energy stored integral design. The core will 

use TRISO for fully ceramic micro-encapsulated (FCM) 

fuel pellets, HALEU enriched to just under 20 %, in 

hexagonal blocks with control rods. Its inherent core 

negative temperature feedback and low power density, 

dissipates heat radiatively and via natural convection. 

Energy conversion is via a 3-loop system with a molten 

salt intermediate (heat exchanger) loop that also stores 

thermal energy. This loop connected to a steam 

generator unit. The concept, under Global First Power, 

has submitted a license to prepare site initial application 

at CNL Chalk River site, and with the CNSC. 

various designs are most clearly revealed in the thermalhydraulic 

design that minimize and/or eliminate potential 

initiating events may be linked to DBA and certainly BDBA 

scenarios. In the latter case, the DBA/BDBA can then be 

claimed as impossible. Reflection of this approach then 

begs the question of prudent integration of the following 

practices: probabilistic risk assessment (PRA), system 

analysis ( RELAP and similar), accident analysis (MELCOR 

and similar) and dispersion analysis. The work by Williams 

et al. [34] describes the safety-in-design, including foremost, 

defense-in-depth and putting into (design) practice, 

the INSAG-10 explicit levels. 

2.3 Gas-cooled, graphite-moderated 

Large scale gas-cooled, often graphite-moderated reactors 

have a history as long as water-cooled, thermal spectrum 

reactors. As such, there have been generational reactor 

concepts paralleling that of LWRs. Much of the 

generational development can be traced to the 1950s to 

1970s, and is associated with the prismatic (block) type 

Magnox and AGR in the UK [41, 42]. The pre-commercial, 

experimental Dragon reactor introduced the TRISO 

(tristructral- isotropic) fuel type. Soon thereafter, the 

German constructed and operated the AVR (Arbeitsgemeinschaft 

Versuchsreaktor), with a pebble bed fuel and 

moderator (spheres) core configuration, demonstrated 

high- termperature operation using gas as coolant. This 

reactor concept is often attributed to Daniels and Schulten, 

and following the AVR saw incremental developments via 

the following: German THTR-300, the Japanese High 

| Figure 1 

U-Battery Design (Source: www.u-battery.com/design-and-technology). 


2.2 Water-cooled, moderated, thermal spectrum 

designs 

Due to the large number of light water-cooled, thermal 

spectrum reactor designs in the history of nuclear energy, 

SMRs based on the similar light water moderation, 

reflection and cooling concepts comprise the largest 

grouping of SMR concepts and designs at present. In fact, 

one of the most complete, if not the only completed design 

is that by NuScale Power. Not surprisingly, many aspects of 

the design, engineering, system design and overall, design 

methodology are proprietary. That said, based on a survey 

of various SMR designs of integral Pressurized Water 

Reactor type (iPWR) by Zeliang, Mi and co-workers [32], if 

the selected core design is conventional (primarily to 

reduce overall cost), but smaller, then differences in 

| Figure 2 

The Micro Modular Reactor (MMR) system (Source: www.usnc.com/mmr-energy-system/). 

Feature 




| Figure 3 

Westinghouse eVinci Micro Reactor 

(Source: www.westinghousenuclear.com/new-plants/evinci-micro-reactor). 

Temperature Test Reactor (HTTR) and Chinese High 

Temperature Reactor, HTR-10. X-Energy’s Xe-100 is the 

current pebble-bed, high temperature, gas-cooled nuclear 

reactor (SMR) design, using TRISO fuel and with targeted 

output at 200 MWth/76 MWe. Consistent with many light 

water based SMR designs, the current day gas-cooled, 

graphite based concepts feature active or passive safety 

features. 

2.4 Unique Reactor Designs 

There are and can be other unique types of SMRs and 

MMRs designs and concepts, differing in selection of fuel 

type, fuel form (solid vs. liquid), neutron energy spectrum, 

the combination of coolant, moderator and reflector, 

thermal/electrical output, safety-in-design and deployment 

strategies, including aspects of modularity, manufactureability, 

cost savings per advance manu facturing 

methods, and “add-on” benefits such as medical isotope, 

hydrogen and district heating production. It may be 

reasonable to say that, assuming that there is ( sovereign) 

regulatory review with inclusion of public consultation of 

any particular SMR design, aspects of technical innovation 

and interest, has to prevail against public sentiment and 

skepticism. Thus, innovative concepts rarely have a chance, 

even in demonstration, and in today’s social media driven, 

multi-national climate, consensus acceptance may be 

needed for certain. In other words, new technology 

solutions have to overcome a daily battle of disinformation 

and misinformation to garner and secure sustainable 

investments and developments. In other words, “the odds 

are not very good, even if the technology (the goods) are 

very innovative (not odd)”. 

2.5 Molten salt-fueled and cooled, 

and fast spectrum, liquid metal designs 

As noted, finishing the SMR design and submitting this for 

regulatory review and approval, as well as commitment to 

construction via sufficient and satisfactory investments, 

are the most important in current SMR efforts. These 

linked objectives also apply to novel SMR/MMR concepts 

based on molten-salt fueled and cooled concepts as well as 

fast spectrum concepts. Historically and technically, fast 

spectrum concepts are often associated with liquid metal 

(sodium, lead, eutectic alloys, etc.) thermal-hydraulic 

system designs. Most notably, large thermal diffusivity 

(and conductivity, relative to water) and selection of 

materials with small neutron cross section, provide design 

advantages in fast spectrum concepts. A succinct summary 

of the sodium-cooled fast reactor is contained in [43]. The 

IAEA “2020 booklet” provides technical specification of 

the Terrestrial Energy’s [39] and Kairos Power’s (fluoride 

salt-cooled, high temperature, pebble bed), [40] designs, 

as well as the fast spectrum designs of the ARC- 

100 (sodium- cooled) and Oklo (MMR, HALEU fuel, 

supercritical CO 2 with heat pipe) concepts. Additional 

information of technical interest can be found via ongoing 

regulatory review processes (examples: US, Canada) and 

open access publications and news releases. Of importance, 

relative to and in contrast to thermal spectrum SMR/ 

MMRs with safety-in-design, is the inherently passive 

safety system feature (including reactivity control) corresponding 

to a defense-in-depth approach, that provides 

competitive, if not advantageous benefit, in the eyes of the 

stakeholders. Because these reactor concepts are or can be 

significantly different than thermal spectrum, water-based 

SMR/MMR designs (example, flowing in-solution liquid 

fuel and coolant), they provide important regulatory 

opportunity to confirm technology “neutrality” when that 

objective is sought. 

There are 11 fast spectrum SMR concepts noted in the 

IAEA – 2020 book. Of these, the Siberian Chemical 

Combine’s, BREST-OD-300, with declared thermal and 

electrical power output, 700 MWt/300 MWe, recently 

received license (from Rostechnadzor) to be constructed 

in Seversk. This, a lead (Pb-cooled and moderated, pool 

type fast reactor, is both a test and demonstration plant. It 

is thus an evolutionary design similar in design to French 

and Japanese one-off SFR designs (Super Phenix, Joyo, 

Monju), but incorporating lessons learned using lead and 

lead-bismuth within the Russian Federation. The core 

consists of mixed uranium-plutonium nitride fuel, 

enriched up to 14.5 %, in hexagonal configuration with 

chromium ferritic-martensitic steel cladding and capability 

for fuel breeding. Reactivity control is via shim and automatic 

control roads, while the 2-loop energy conversion 

system features a lead to water steam generator system. 

The emergency core cooling system is passive, and consists 

of pipes immersed directly into the primary system, thus 

serving as a natural circulation driven lead-to-air heat 

exchanger. Completion of construction is scheduled to be 

as early as 2026. 

It is worth noting that in terms of safety-in-design of 

liquid-metal cooled fast reactors, the key safety feature is a 

prompt, negative temperature feedback from Doppler 

broadening of the cross section. In simple terms, because 

of the combination of higher fuel enrichment (relative to 

water-cooled reactors), liquid metal as coolant and 

subsequent compactness of the overall core design, the 

power density of a fast reactor is larger than water-cooled 

reactors. Thus, the probability of an initiating event 

developing into an energetic event has to be considered. 

The safety-in-design of the EBR-II test/demonstration 

plant considered many of these aspects and demonstrated 

its inherent safety. In brief, historically documented 

( accident) phenomena specifically for sodium-cooled 

designs include the following: transient overpower, lossof-flow, 

fuel- vapor explosion, sodium vapor explosion, 

containment response under short and sustained loads. 

For specific liquid metal cooled, SMR-scale fast spectrum 

designs, these specific issues have to be addressed. 

It remains to be seen how the ARC-100 SFR will develop 

as a scaled-down, updated version of EBR-II [44], with 

some of the original EBR-II lead principals. The ARC-100 is 

a forced circulation SFR, thermally projected to be 

286 MWt/100 MWe, and featuring U-Zr metallic fuel, 

enriched on average to 13.1 %, such that it has a 20-year 

refueling service life. Beyond the primary circuit, it 

features a 2-loop IHX to SG design, supported by four 

submersed EM pumps. The SG is a vertically oriented, 

helical coil, single-walled, counter-flow sodium-to-water, 

shell-in-tube design. Reactivity control is via a redundant 

Feature 



system of 6 control rods (3 x 2). Besides the core, many of 

the major energy conversion system components are 

integrated into the reactor vessel and defining building. 

The ARC-100 is undergoing CNSC Vendor Design Review 

and has Provincial support from New Brunswick ( Canada). 

Generational knowledge preservation and transfer, as well 

as workforce capability to understand the SFR remains to 

be seen. 

Finally, we would be remiss if the long-standing promise 

of fast reactors as part of national energy self-sufficiency 

strategy via closing of the nuclear fuel cycle, is not noted. 

Unfortunately, no nuclear nation today completely 

practices a fully closed (commercial) nuclear fuel cycle 

and thus, with fast reactors of a SMR “kind”, we have to 

again maintain a sensible view to technology readiness of 

fuel reprocessing aspects for those fast SMR concepts that 

use existing supplies of spent fuel. Except possibly in China 

and the Russian Federation, openly competitive global 

markets have eroded the promise of fast reactors and 

closed fuel cycle. 

3 Lesson learned, evolution of 

safety-in-design, getting to the end 

One can look at the 70+-year history of nuclear power 

generation of electricity, and relative to other public use/ 

acceptance of other risk-inherent technologies such 

as the automobile and travel via commercial airlines 

(approximately 100 years), begin to understand the 

development of social license/public acceptance of 

technologies. Once could state that unfortunately, nuclear 

power developed alongside environmental consciousness 

and a spectrum of “anti” movements that continue to this 

day. This paper is not intended to argue rightful acceptance 

of nuclear power. However, not preserving the options 

presented by nuclear generated electricity would be 

testimony to lack of foresight in the world we live in today, 

with the issues and challenges that we have. 

The ongoing “nuclear renaissance” of recent years can 

be summarized in terms of the following trends: 1) 

conceptual designs followed by various states of 

engineering design development of many types of SMRs 

and MMRs, 2) a broad discussion of the socio- technological 

importance of addressing (the emerging, negative impacts 

of) climate change, and thus, transitioning away from a 

carbon-based (fossil fueled) to low carbon or net zero 

carbon economies of scale using nuclear energy, and 3) unbeknownst 

to many but integration of lessons learned, 

evolution in safety-in-design thinking, and advancements 

in modeling and simulation (using high performance 

computing) for advanced reactor designs. Recent 

advancements in accident tolerant fuels, and advanced 

manufacturing are noted but perhaps years away from 

being inherent in SMR/MMR design. 

4 Emerging drivers in SMR and 

advanced reactor concept design 

The ongoing global interest and enthusiasm for SMR/ 

MMR has generated many concepts but equally revealed 

uncoordinated global gaps, including regulatory review of 

the safety-in-design of various concepts. This is to be 

expected, given that regulatory mandate is at the national 

level. That said, there are a few bi-/tri-lateral collaboration 

agreements to share regulatory practices. It remains to 

be seen whether such collaborations will facilitate review 

and thus reduce the overall time to realizing any 

particular SMR/MMR concept. We further note that global 

institutions, such as the IAEA, WNA, OECD-NEA, WANO 

| Figure 4 

Conceptual sketch of weighting factor assignment. 

and related promote common understanding – here with 

respect to safety-in-design of SMRs/MMRs and other 

advanced reactor concepts. The authors herein describe 

emerging drivers or influences, based on many lessons 

learned in reactor concepts and designs. We offer this 

account since, design methods and approaches often 

remain proprietary and as such, not openly discussed. We 

thus offer for contemplation and discussion, high-level 

aspects of safety-in-design of SMRs. 

Figure 4 first shows a qualitative “high, medium or 

low” weighting in importance versus the INSAG-10 levels 

(1 to 5), meant to reflect historial perspective on defencein- 

depth. The figure compares conventional reactors 

( larger plants) versus SMRs currently proposed. We note 

that the weigthing for convential reactors may sensibly 

decrease incremental manner if level “1, 4, 5”, for example, 

loosely correspond to AOOs, DBA an BDBA respectively. 

That is, convential reactors have largely been designed so 

that safety systems can respond to and counter consequences 

of the postulated DBA. However, history has 

taught us that human operational error can generate 

BDBA-type situations; that is, leading to core meltdown 

(degradation) and (unintended) release of radioactivity 

beyond the plant boundary. Thus, for older generation 

reactor designs (Generation II), one could imagine a 

higher weighting for levels 1-to-3, relative to levels 4-to-5 

event. Since, the authors anticipate arguments under such 

qualitative perspectives, an uniform, medium weighting 

across levels, 1-to-5, is also shown. It is conceivable that a 

particular, recent design (Generation III, III+) could 

feature uniform weighting as depicted. 

In contrast, the designs of current SMRs are generally 

expected to reflect generational improvements in safety- indesign, 

overall. Thus, at minimum, the SMR may feature 

inherent, passive safety system/s in its design, and thus 

reflect a safety-in-design philosophy, that may emphasize 

at least “M” weighting for unlikely, level “4 or 5” scenarios. 

In so doing, the design eliminates the need for immediate 

(human) emergency response. This latter philosophy may 

not always be apparent by studying the design itself, but 

depicted through an integration of a number of safety- indesign 

aspects. In reality and with operational excellence 

taken into consideration, the relationship may be 

something similar to the (non-linear) dotted trend with 

high imporance placed on both low and higher level 

scenarios. Any difference in magnitude or slope comparing 

conventional reactors to SMRs, thus reflects historical 


Feature 




DiD 

Level 

SMR target 

frequency (/yr)* 

No. Generic eliminated scenarios Contributing innovative features 

1. Large Break Loss of Coolant Accidents (LB-LOCAs) Integrated Reactor Cooling System 

2. Elimination of control rod ejection/injection accidents Integrated Control Rod Drive Mechanisms (CRDMs) 

3. Exclusion of inadvertent reactivity insertion as a result of boron dilution Eliminated liquid boron reactivity control system 

4. Elimination of loss of flow accidents and failures/scenarios related to 

reactor coolant pumps 

Naturally circulated primary system 

5. Elimination of the need for external power under accident conditions Fail-safe passive safety features on loss of power 

| Table 2 

SMR design features that challenge conventional safety analysis. 

Design characteristics 

Integral reactor coolant system (RCS)- 

design-reduced accident initiators 

Attributes 

Level 1 < 10 -2 Initiating event frequency 

Level 2 < 10 -5 Failure detection capability and control action 

(automatic or manual) 

Level 3 < 10 -8 Core damage frequency (CDF) 

Facilitating factors in (SMR) passive safety systems (PSSs) start-up/operation 

Minimizes accident initiators, thus consider use of PSS. 

Results in a simplified design 

Lower core power capacity Less (magnitude) decay heat to be removed 30) 

PRA 

Levels 

Level 1 

Level 4 < 10 -10 Conditional containment failure probability Level 2 

Level 5 < 10 -12 Large early release frequency (LERF) Level 3 

| Table 1 

Relationship among DiD, PRA, existing requirements and expectations. *small values can be argued, conservatively 

Current regulatory 

requirements (/yr) 

< 1 x 10 -5 and < 1 x 10 -4 

(depending on regulator) 

< 0.1 


< 1 x 10 -6 


Larger surface to volume ratio 

Larger primary coolant inventory 

per MW(th) 

Smaller reactor core power density 

Large secondary coolant inventory, 

e.g., NuScale reactor pool 

Taller and broader reactor pressure 

vessel or vessel containing core 

Facilitates decay heat removal due to large surface area, 

particularly for single phase flow 

Larger heat sink for natural circulation; larger buoyancy-driven 

flows/regioins; reduces requirements for heat removal systems 31) 

Larger thermal-hydraulics margins; favourable in long term decay 

heat removal, in particular via PSSs 

Facilitates passive decay heat removal and 

containment cooling 10) 

Facilitates decay heat removal via natural circulation, 

i.e., higher elevation difference between heat source and sink 30) 

| Table 3 

SMR design features that challenge conventional safety analysis. 

lessons learned and competing philosophies in safety- indesign 

of nuclear reactors. 

Continuing, Table1 below provides a semi-quantitative 

equivalent to Figure 4 but compares INSAG-10 levels, 

against the possible SMR target frequencies (a design 

merit), short descriptors of the corresponding attributes of 

an event or accident, the commonly noted PRA levels, and 

the currently known regulatory values for existing plants. 

This table is qualitative and simply contrasts different 

perspectives that may be used by a SMR designer. We 

recognize that small frequency values, say less than 1E-08, 

may not hold regulatory meaning and as such, higher 

frequencies for levels 1-5 may apply, depending on the 

practicality of such values in regulatory review of 

submitted SMR/MMR designs and concepts. Finally, as a 

measure of confidence in its design, a vendor may assume 

a probability 3 orders of magnitude smaller at each level, 

except at level 4-and-5. 

Table 2 provides five representative, generic events 

for which design features and/or design concepts of 

recent SMRs (also MMRs), have either greately reduced or 

eliminated all together the likelihood of such vulnerabilities, 

most often associated with conventional reactor 

designs. Here again, through gradual advancements in 

conventional reactor safety-in-design, further facilated by 

ongoing development in SMRs, safety-in-design and 

defencein-depth have both been embodied in various 

SMR designs. The rightmost column gives an example of 

the SMR design feature that eliminated the generic 

scenarios. 

Finally, Table 3 representative design characteristics 

or features observed in recent iPWR-type SMRs (left 

column), relative to their phenomenolgical impact in 

assuring energy removal under many severe accident 

scenarios and design vulnerabilties associated with 

conventionl reactor designs. Further, for a given SMR design 

encompassing a mulitple number of design characteristics 

as above, operator intervention is greatly reduced or eliminated 

for substantial durations of time, starting from the 

initiating event and possibly linked to an additional 

sequence of unlikely events. In other words, current SMR 

designs anticipate BDBA and catastrophic, external events. 

Feature 



5 Uphill costs and getting to the end 

It is no secret there are major milestones on the path to 

realizing any new commercial nuclear power plant. Some 

major milestones that come to mind are first criticality and 

connection to the electricity grid. New conventional builds 

have however become too expensive, relative to other 

large infrastructure projects and public spending that 

address regional to national priorities. As ramification of 

the Fukushima Daiichi earthquake-tsunami-nuclear plant 

accident, and examples of cost overruns and delays associated 

with large nuclear plant projects persist, “opportunist” 

have taken sides – to either support or not support 

nuclear energy as a valued energy source option. It is well 

known that the merits of nuclear power (as zero to low 

carbon) in addressing the negative impacts of climate 

change, continue to be argued in public and social media 

spaces. Pragmatism regarding public infrastructure need 

can become easily mired and disconnected to those elected 

and engaged in media. If the authors may inject opinion, 

nuclear energy is an energy technology that we have today 

and it provides, at minimum, the time needed for society to 

reach consensus via change in mindsets, values and beliefs. 

This lead author is of the opinion that addressing climate 

change is just as much a matter of change needed in how 

we live and consume. Energy consumption and its sources 

are very much part of the anthropocene. 

While various perspective on developments in SMRs/ 

MMRs can be taken, the authors’ position here is that 

getting to the “end” may be the most important. 

6 Conclusion 

Development of various Small- and Micro-Modular 

Reactor concepts, regardless of its point of origin depends 

on alignment of both timely and prudent engineering and 

design efforts, sustained financial backing during this 

effort and, public and/or private stakeholder investments 

so that a first-of-a-kind reactor (FOAK) is constructed on 

time and at cost, post timely regulatory safety-in-design 

approval. Beyond the FOAK plant, expectations are such 

that sustained investments and commitments, parallel 

reduction in cost with each additional unit constructed in 

modular manner. 

Here the authors have elaborated on a holistic safety- indesign 

perspectives wherein technical features make 

design and beyond design basis accidents nearly impossible 

(or eliminated), and even under improbable initiating 

events, decay heat removal is passive such that it does not 

require operator intervention for a defined length of time. 

The article also emphasized that completion of the design 

and (time) efficient regulatory review of the submitted 

design, are of tantamount importance with respect to the 

sustained investments, and can determine the fate of any 

given SMR/MMR design. It is clear that regional to national 

support of nuclear energy, an existing history of reactor 

design development, a skilled nuclear and energy sector 

workforce, and an existing supply chain are increasingly 

expected conditions when considering new nuclear plants. 

Finally, early public engagement and confirmation of 

gradual public acceptance and social license (nominal 

acceptance of nuclear energy) must exist, as identified via 

fleeting social media platforms. This is the reality of the 

world that we live in today. Let us brave the future of 

nuclear energy. 

Acknowledgments 

The lead author thanks Ontario Tech University and its 

Faculty of Energy Systems and Nuclear Science. He also 

thanks contributions to recent research on SMRs from 

Chireuding Zeliang and Yi Mi. The lead author would 

like to thank partial support by the National Science, 

Engineering Research Council (of Canada), CREATE 

528176-2019, awarded to McMaster University with 

Ontario Tech University as partnering institution. 

References 

[1] International Atomic Energy Agency, “Design Safety Considerations for Water Cooled Small 

Modular Reactors Incorporating Lessons Learned from the Fukushima Daiichi Accident”, 

TECDOC-1785, IAEA, Vienna (2016). 

[2] International Atomic Energy Agency, “Advances in Small Modular Reactor Technology 

Developments”, A supplement to: Advanced Reactors Information System, IAEA, Vienna (2016). 

[3] Ramana, M. V., L. B. Hopkins, and A. Glaser, “Licensing small modular reactors”, Energy 61, 

555-564 (2013). 

[4] Locatelli, G., C. Bingham, and M. Mancini, “Small modular reactors: A comprehensive overview of 

their economics and strategic aspects”, Progress in Nuclear Energy 73, 75-85 (2014). 

[5] Nuclear Energy Agency, “Current Status, Technical Feasibility and Economics of Small Nuclear 

Reactors”, Organisation of Economic Cooperation and Development, France (2011). 

[6] Subki, M.H., “Advances in Development and Deployment of Small Modular Reactor Design and 

Technology”, presentation at ANNuR-IAEA-USNRC Workshop on SMRs Safety and Licensing,- 

Vienna, Austria (2016). 

[7] International Atomic Energy Agency, “Safety of Nuclear Power Plants: Design, Specific Safety 

Requirements No. SSR-2/1 (Rev. 1)”, IAEA Safety Standards, Vienna (2016). 

[8] International Atomic Energy Agency, “Technical feasibility and reliability of passive safety 

systems for nuclear power plants”, TECDOC-920, IAEA, Vienna, Austria (1994). 

[9] Carelli, M.D., and Ingersoll, D. T., “Handbook of small modular nuclear reactors”, Elsevier (2014). 

[10] NuScale Power, L. L. C, “NuScale plant design overview”, United States Nuclear Regulatory 

Commmission, Washington DC (2012). 

[11] Kim, K. K., et al., “SMART: the first licensed advanced integral reactor”, Journal of Energy and 

Power Engineering, vol. 8.1, 94 (2014). 

[12] Petrovic, B., M. Ricotti, S. Monti, N. Čavlina, and H. Ninokata, “Pioneering role of IRIS in the 

resurgence of small modular reactors”, Nuclear Technology 178, no. 2, 126-152 (2012). 

[13] Magan, H. Boado, et al., “CAREM project status”, Science and Technology of Nuclear Installations, 

Vol. 2011, Article ID 140373 (2011). 

[14] International Atomic Energy Agency, “Defense in Depth in Nuclear Safety. A report by the 

International Nuclear Safety Group”, INSAG-10, IAEA, Vienna (1996). 

[15] Canadian Nuclear Safety Commission, “Small Modular Reactors: Regulatory Strategy, Approaches 

and Challenges”, Discussion paper DIS-16-04 (2016). 

[16] Ingersoll, D. T., “An overview of the safety case for small modular reactors”, ASME 2011 Small 

Modular Reactors Symposium, American Society of Mechanical Engineers (2011). 

[17] U.S. Code of Federal Regulations, “General Design Criteria for Nuclear Power Plants,” 

Introduction, 10 CFR 50 Appendix A, US NRC, (2015). 

[18] International Atomic Energy Agency, “Basic Safety Principles for Nuclear Power Plants”, 

INSAG-12, IAEA, Vienna (1999). 

[19] LaChance, J., et al. “Evaluation of the Applicability of Existing Nuclear Power Plant Regulatory 

Requirements in the US to Advanced Small Modular Reactors.” SAND2013-3683, Sandia 

National Laboratories, Albuquerque, NM (2013). 

[20] International Atomic Energy Agency, “Progress in Methodologies for the Assessment of Passive 

Safety System Reliability in Advanced Reactors”, TECDOC-1752, IAEA, Vienna (2014). 

[21] NuScale Power, LLC Submittal of, “Methodology for Establishing the Technical Basis for Plume 

Exposure Emergency Planning Zones at NuScale Small Modular Reactor Plant Sites”, Revision 1, 

TR-0915-17772, Corvallis, USA (2018). 

[22] Apostolakis, G., et al., “A proposed risk management regulatory framework”, NUREG-2150, 

US Nuclear Regulatory Commission, (2012). 

[23] Williams, C., W. J. Galyean, and K. B. Welter, “Integrating quantitative defense-in-depth 

metrics into new reactor designs”, Nuclear Engineering and Design, 330, 157-165 (2018). 

[24] Chierici, L., Fiorini, G.L., La Rovere, S. and Vestrucci, P., “The Evolution of Defense in Depth 

Approach: A Cross Sectorial Analysis. Open Journal of Safety Science and Technology, 6, 35-54 

(2016). 

[25] International Atomic Energy Agency, “A Framework for an Integrated Risk Informed Decision 

Making Process”, INSAG-25, IAEA, Vienna (2011). 

[26] International Atomic Energy Agency, “Safety related terms for advanced nuclear plants”, 

TECDOC-626, IAEA, Vienna, Austria (1991). 

[27] International Atomic Energy Agency, “Passive Safety Systems and Natural Circulation in Water 

Cooled Nuclear Power Plants”, TECDOC-1624, IAEA, Vienna, Austria (2009). 

[28] General Electric Company, “The ESBWR Plant General Design Description”, GE Nuclear Energy, 

NC, USA (2007). 

[29] Schulz, T.L. “Westinghouse AP1000 advanced passive plant.” Nuclear Engineering and Design 

236.14-16, 1547-1557 (2006). 

[30] International Atomic Energy Agency, “Design Features to Achieve Defence in Depth in Small and 

Medium Sized Reactors”, Nuclear Energy Series NP-T-2.2, IAEA, Vienna (2009). 

[31] Hidayatullah, H., et al., “Design and technology development for small modular reactors–Safety 

expectations, prospects and impediments of their deployment”, Progress in Nuclear Energy 79, 

127-135 (2015). 

[32] Zeliang, C., Mi, Y., Tokuhiro, A., Lu, L., and Rezvoi, A. (2020). Integral PWR-Type Small Modular 

Reactor Developmental Status, Design Characteristics and Passive Features: A Review. Energies 

(Basel), 13(11), 2898–. https://doi.org/10.3390/en13112898 

[33] IAEA –International Atomic Energy Agency, Advances in Small Modular Reactor Technology 

Developments (2020). 

[34] Williams, C., Galyean, W. J., & Welter, K. B. (2018). Integrating quantitative defense-in-depth 

metrics into new reactor designs. Nuclear Engineering and Design, 330(C), 157–165. 

[35] Kloosterman, J. (2018). Molten Salt Reactors and Thorium Energy, edited by Thomas J. Dolan 

[Review of Molten Salt Reactors and Thorium Energy, edited by Thomas J. Dolan]. Annals of 

Nuclear Energy, 117, 1–2. Elsevier Ltd. https://doi.org/10.1016/j.anucene.2018.02.017 


Feature 




[36] Zohuri, B.. Small Modular Reactors as Renewable Energy Sources . Cham, Switzerland: Springer, 

2019. Print. 

[37] Canadian Nuclear Safety Commission, Pre-licensing Vendor Design Review. 

http://nuclearsafety.gc.ca/eng/reactors/power-plants/pre-licensing-vendor-design-review/ 

index.cfm 

[38] Irish, S., and LeBlanc, D. (2018). Driving change with IMSR: Terrestrial Energy’s integral molten 

salt reactor is redefining what a nuclear plant can do. Nuclear Engineering International, 

63(773), 20–. 

[39] Blandford, E., Brumback, K., Fick, L., Gerardi, C., Haugh, B., Hillstrom, E., Zweibaum, N. (2020). 

Kairos power thermal hydraulics research and development. Nuclear Engineering and Design, 

364(C), 110636–. 

[40] Hussein, E. Emerging small modular nuclear power reactors: A critical review. Physics Open, 5, 

100038 (2020) 

[41] Wikipedia article on “Magnox”, as of March 29, 2021; https://en.wikipedia.org/wiki/Magnox 

[42] Wikipedia article on “Advanced Gas-cooled Reactor”, as of March 28, 2021; 

https://en.wikipedia.org/wiki/Advanced_Gas-cooled_Reactor 

[43] Wikipedia article on “sodium-cooled fast reactor, as of April 10, 2021; 

https://en.wikipedia.org/wiki/Sodium-cooled_fast_reactor#:~:text=A%20sodium%2Dcooled%20fast%20reactor,metal%2Dfueled%20integral%20fast%20reactor. 

[44] Wikipedia article on “Experimental breeder reactor II”, as of April 10, 2021; 

https://en.wikipedia.org/wiki/Experimental_Breeder_Reactor_II 

Authors 

Prof. Akira Tokuhiro 

Dean and Professor at the Faculty 

of Energy Systems and Nuclear Science 

Ontario Tech University, Ontario, Canada 

Akira.Tokuhiro@ontariotechu.ca 

Akira Tokuhiro is Dean and Professor at the Faculty of Energy Systems and Nuclear 

Science at Ontario Tech University in Oshawa, Ontario, Canada. His primary R&D 

interests are in development of advanced reactor concepts, including small modular 

reactors. He joined Ontario Tech University from NuScale Power. He has nuclear and 

energy R&D experiences in Switzerland, Japan, USA and Canada. 

Yi Mi 

Master of Applied Science in Nuclear Engineering 

yi.mi@uoit.net 

Yi Mi is a young nuclear engineering professional with research experience in 

Probabilistic Risk Assessment (PRA) and Small Modular Reactor (SMR) Technology 

Development. He completed his Master of Applied Science degree in January 2020, 

in Nuclear Engineering, at Ontario Tech University His research was on SMRs, 

especially integral Pressurized Water Reactors (iPWRs). His focus was on safetyin-design 

methodology of small modular reactors (SMR). Specifically, he was 

integrating a number of tools and methods such as, system analysis and 

probabilistic risk analysis codes (LabVIEW and CAFTA), but including in the 

methodology, scaling analysis of iPWR type SMR with passive safety systems. 

Also, he studied the similarity and differences among different types of SMRs 

including iPWR, Steam Cycle-High Temperature Gas-Cooler Reactor (SC-HTGR), 

Fluoride-salt-cooled High Temperature reactor (FHR) and CO2-cooled micro modular 

reactor (MMR). Before OntarioTech, hec ompleted a Bachelor of Engineering in 

Chemical Engineering in Sichuan University. 

Chireuding Zeliang 

Junior Engineer/Analyst 

Kinectrics Inc., Toronto, Canada 

Chireuding Zeliang is a young nuclear engineering professional with research and 

work experience in Probabilistic Risk Assessment (PRA) and Small Modular Reactor 

(SMR) Technology Development. He currently works with Kinectrics Inc. as a Junior 

Engineer/Analyst in the areas of PRA as well as Design Modification of Safety and 

Supporting systems in CANDU nuclear plants. Prior to joining Kinectrics, Chireuding 

pursued his research career in PRA and SMR Technology Development from University 

of Ontario Institute of Technology under a 15 countries collaborative IAEA Coordinated 

Research Project on ‘Design and Performance Assessment of Passive Engineered 

Safety Features in Advanced SMRs’. He holds two (2) Master’s degree from 

University of Ontario Institute of Technology and Indian Institute of Technology 

Kanpur, and a Bachelor’s degree from North Eastern Regional Institute of Science 

and Technology, India. 

Feature 



Did you know? 

Nuclear Power as Part of Sustainable Energy Policy – 

UNECE Working Group Report 

In the 2021 report “Application of the United Nations Framework 

Classification for Resources and the United Nations Resource 

Management System: Use of Nuclear Fuel Resources for Sustainable 

Development Entry Pathways” prepared by the Expert 

Group on Resource Management (EGRM) of the United Nations 

Economic Commission for Europe (UNECE) the role of nuclear 

energy is explored in the framework of the UN‘s 2030 Agenda 

for Sustainable Development. Key insights of this work among 

other are: 

p “Nuclear energy is an indispensable tool for achieving the 

global sustainable development agenda. It has a crucial role 

in decarbonizing the energy sector, as well as eliminating 

poverty, achieving zero hunger, providing clean water, 

affordable energy, economic growth, and industry innovation. 

...” 

p “Nuclear energy entry pathways for newcomer countries align 

with the 2030 Agenda for Sustainable Development. Nuclear 

energy programmes, based on the IAEA‘s Milestones 

Approach, support national energy needs, socio-economic, 

and environmental goals, and can help countries meet international 

climate commitments” 

p “Currently available nuclear reactor designs are based on 

mature and proven technologies that in some instances have 

been licensed to operate for 80 years. ... They provide reliable, 

affordable and low-carbon electricity that will support a 

country in meeting its sustainable development goals.” 

The report states to meet “a need expressed by global decision 

makers to better understand the role nuclear energy may play in 

the energy transition”. It gives advice on how to foster and embed 

the entry into nuclear energy in a larger framework of policies 

and recommendations on how to facilitate the implementation of 

a nuclear energy programme. The “embedding” policies include 

policies for sustainable development and a low-carbon energy 

transition, energy market reforms that support long term strategic 

investment, policies to improve energy security and resilience 

and an industrial development strategy. Typical policies aiming 

for a low carbon energy system that foster nuclear power are 

deep decarbonization or a net-zero carbon target, technologyneutral 

low-carbon energy portfolio standards, coal/fossil fuel 

phase- outs, increasing electrification of heat and transport, 

decarbonization and modernization of energy-intensive industries. 

Regarding the electricity market design the report calls 

among other to value energy reliability, resilience and the need 

for technologies providing secure, reliable and dispatchable 

generation to support the integration of variable renewables. It 

proposes as well to include non-power (socio-economic) benefits. 

The report makes mention of the assessment in a recent OECD- 

NEA report that for a generalized country the most cost-effective 

option to achieve a decarbonization target of 50 g CO 2 /kWh is a 

mix relying primarily on nuclear energy. Even in cases with ultralow-cost 

wind and solar PV an aggressive decarbonization target 

would require a share of 40 – 60 percent dispatchable low-carbon 

technologies such as nuclear. 

When eventually a decision in favour of nuclear power has been 

reached, supporting measures for implementation according to 

the report are international cooperation, regulatory harmonization, 

the development of indigenous capabilities, the delivery of 

projects on time and on budget, the proactive engagement of 

stakeholders and diversity in the nuclear sector with regard to 

gender balance. The report also assesses the issues of sustainable 

resource management, socioeconomic and environmental 

factors, the nuclear fuel cycle, nuclear waste management 

and disposal as well as nuclear technologies and innovation 

perspectives among other. 

DID YOU EDITORIAL KNOW? 

17 

200 

150 

100 

Projected Costs of Energy Technologies by 

Country (2020) in USD/MWh (Median LCOE) 

(Data: IEA) 

External Costs of Health effects for 

14 Technologies as of 2025, 

NEEDS study 2009 

 

Lignite 

Lignite post-comb CCS 

Lignite oxy-fuel CCS 

Coal 

Coal post-comb CCS 

Coal oxy-fuel CCS 

CCGT 

in Euro cent/kWh 

Source: 

Application of the United 

Nations Framework 

Classification for 

Resources and the 

United Nations Resource 

Management System: 

Use of Nuclear Fuel 

Resources for Sustainable 

Development – Entry 

Pathways, Expert 

Group on Resource 

Management (EGRM), 

United Nations Economic 

Commission for Europe 

(UNECE), Geneva 2021 

CCGT CCS 

50 

0 

India United States China Europe Japan 

Coal Gas 

(CCGT) 

Nuclear Onshore 

wind 

(> = 1MW) 

Offshore 

wind 

Solar PV 

(utility scale) 

Wind 

PV 

Solar Thermal 

Biomass 

Ocean 

Nuclear 

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 

For further details 

please contact: 

Nicolas Wendler 

KernD 

Robert-Koch-Platz 4 

10115 Berlin 

Germany 

E-mail: presse@ 

KernD.de 

www.KernD.de 

Did you know?


18 

The Nuclear Innovation Policy of Canada 

INTERVIEW 

Q&A with the Ministry of Natural Resources Canada 

Canada pursues an ambitious climate policy and is strongly committed to nuclear innovation. Today Canada is a 

front runner in the development, design review and licensing of micro, small modular and advanced modular reactors. 

Natural Resources Canada (NRCan) supported this development with Canada’s SMR Roadmap process in 2018 and the 

SMR Action Plan which is expected to yield concrete results within this decade. Canadian nuclear innovation policy 

aims beyond decarbonization in Canada and the fulfillment of specific Canadian local energy needs. Part of the policy 

is to establish new nuclear technologies globally as part of climate solutions and become a prime supplier of such 

technologies. The Q&A below with the Ministry of Natural Resources Canada (NRCan) gives you insights on the 

Canadian nuclear policy, its consensual making, its goals and the current state of progress. 

About the SMR Action Plan 

Canada's Small Modular Reactor (SMR) Action Plan is 

Canada's plan for the development, demonstration and 

deployment of SMRs for multiple applications at home and 

abroad. 

SMRs are a promising new technology that could unlock a 

range of benefits: economic, geopolitical, social, and 

environmental. Canada’s SMR Action Plan brings together 

essential enabling partners, leveraging their strengths to 

lock-in these benefits and lead the world on SMRs. 

The Action Plan is the result of a pan-Canadian effort 

bringing together key enablers from across Canada, which 

are called “Team Canada” – the federal government, 

provinces and territories, Indigenous Peoples and communities, 

power utilities, industry, innovators, laboratories, 

academia, and civil society. 

Each of these key enablers has contributed a chapter to the 

Action Plan, describing a concrete set of actions they 

are taking to seize the SMR opportunity for Canada. 

Collectively, these chapters demonstrate the breadth of 

engagement on SMRs across the country and outline the 

depth of progress and ongoing efforts. 

Canada has a long and impressive tradition in the 

use of nuclear energy and nuclear technologies. 

The CANDU reactors have been successfully 

developed and introduced; the only commercial 

non-LWR technology with worldwide recognition. 

From your point of view, what are the Canadian´s 

Government expectations for the nuclear sector? 

Small modular reactors (SMRs) are a potential gamechanging 

technology that can help Canada meet and 

exceed its emissions targets while creating economic 

opportunities in a post-pandemic world. 

Nuclear energy plays an important role in Canada’s 

current energy mix, accounting for 15 percent of our 

electricity supply, including approximately 60 percent of 

our supply in Ontario and approximately 40 percent in 

New Brunswick. The sector also contributes approximately 

$17 billion a year to Canada’s gross domestic product, and 

accounts for approximately 76,000 jobs across the country, 

including over 200 small- and medium-sized enterprises. 

SMRs are an opportunity for Canada to produce nonemitting 

power where it’s needed. The Government of 

Canada recognizes that it has a role to play in supporting 

this emerging innovative sub-sector, and in enabling 

Canada to seize these benefits. 

With the “SMR Road Map” and the recent “SMR 

Action Plan” from December 2020 Canada places 

itself on the forefront of this technology. What are 

the primary objectives of this SMR policy? 

SMRs have the potential to support Canada in its 

goals to reach net-zero by 2050 by accelerating electricity 

decarbonization, moving Canadians off coal and diesel, 

and driving deep indus trial decarbonization, all while 

creating jobs for Canadians. 

Over 100 organizations have submitted chapters to 

the Action Plan. For more information on our SMR 

Roadmap and Action Plan, see the ‘About’ section here: 

https://smractionplan.ca/ 

What are the main advantages and prospective 

applications of this technology? 

SMRs are nuclear reactors that are: 

p smaller, with a lower up-front capital investment than 

traditional nuclear power plants; 

p simpler, involving modular designs and a fleet-based 

approach to control cost and shorten project schedules; 

and 

p cheaper to compete with alternatives, enabling new 

applications such as hybrid nuclear-renewable energy 

systems. 

Many SMR designs also offer enhancements to improve 

safety, performance, and prevention of accidents. 

In Canada, SMRs have three major areas of application: 

p on-grid power generation, especially in provinces 

phasing out coal in the near future. Utilities want to 

replace end-of-life coal plants with non-emitting baseload 

plants of similar size; 

p on- and off-grid combined heat and power for heavy 

industry, such as cement producers; and 

p off-grid power, district heating, and desalination in 

remote communities. These currently rely almost 

exclusively on diesel fuel, which has various limi tations. 

Interview 

The Nuclear Innovation Policy of Canada ı Ministry of Natural Resources Canada


The “SMR Action Plan” assembles an impressively 

broad coalition of stakeholders from many 

segments of society. How was it possible to gain 

so much and diverse support for the Canadian 

SMR endeavor? 

Natural Resources Canada ( NRCan) recognizes the 

potential for this emerging area of nuclear innovation and 

understands the importance of diverse, strategic partnerships. 

That’s why, in 2018, NRCan convened Canada’s SMR 

Roadmap, a ten-month cross- country conversation on 

Canada’s SMR opportunity that brought together 

provincial and territorial governments, power utilities, 

industry and other interested stakeholders to chart a path 

forward for this technology in Canada. The report made 

over 50 recommendations, which Canada’s SMR Action 

Plan responds to and builds on. 

The SMR Action Plan is the result of a pan-Canadian 

effort bringing together key enablers from across Canada, 

including the federal government, provinces and territories, 

Indigenous Peoples and communities, power utilities, 

industry, innovators, laboratories, academia, and civil 

society. Each of these key enablers contributed a chapter to 

the Action Plan, describing a concrete set of actions they 

are taking to seize the SMR opportunity for Canada. 

Collectively, these chapters demonstrate the breadth of 

engagement on SMRs across the country and outline the 

depth of progress and ongoing efforts. 

INTERVIEW 19 

Decarbonization is a global challenge, not a 

challenge for single countries or regions. Is the 

export and the sharing of know-how of Canadian 

nuclear technology to other countries part of the 

“SMR Action Plan”? 

The SMR Action Plan is Canada’s plan for the development, 

demonstration and deployment of SMRs for multiple 

applications at home and abroad. Over the past six 

decades, the Government of Canada has successfully 

established and maintained strategic bilateral and multilateral 

partnerships around the globe to advance shared 

nuclear energy priorities. With our own power reactor 

technology and full-spectrum nuclear capabilities, Canada 

belongs to an elite group of Tier 1 nuclear nations. 

With demonstrated leadership and expertise in nuclear 

science and technology, Canada is in a position to lead 

and contribute to international partnerships to support 

the development and deployment of SMRs across the 

globe. 

What is the timeline of SMR projects in Canada and 

which are the closest to realization? 

The Government of Canada understands the important 

role it has to play in advancing SMR technology in time for 

Canada to be a world leader and to provide a non-emitting 

alternative for jurisdictions that must phase out conventional 

coal-fired power plants by 2030. The Government of 

Canada also recognizes the leadership of provincial and 

territorial governments and power utilities in SMR deployment, 

and plans to continue working together to make 

Canada a world leader in SMR technology. 

Several provinces that must phase out conventional 

coal-fired power plants are at a critical decision point for 

new electricity sources, and the commercialization of 

SMRs could allow these provinces to achieve and lock in a 

decarbonized energy mix. 

The ongoing projects in Ontario to extend the life of the 

Darlington and Bruce nuclear plants have led to a rampedup 

nuclear supply chain, creating thousands of new jobs. 

| This map shows that all uranium comes from mines in Saskatchewan, but uranium processing, 

refining, conversion, fuel fabrication, research and waste management happens across Canada. Nuclear 

power stations are located in Ontario and New Brunswick. (Source: Natural Resources Canada) 

As these projects end in the late 2020s and early 2030s, 

SMR projects could present an opportunity to sustain this 

capacity into the long term, as found through Canada’s 

SMR Roadmap. In other regions throughout the country, 

including Atlantic, Western and Northern Canada, SMRs 

are an opportunity to develop a new economic driver 

supporting good, middle-class jobs, and the Government 

of Canada supports efforts to enable all regions to benefit 

from Canada’s SMR oppor tunity. 

Through Canada’s SMR Action Plan, SaskPower identified 

that they are evaluating several potential low 

emissions pathways, including the deployment of nuclear 

power from SMRs in the 2032 – 2042 timeframe, with a 

view to limiting the deployment of new natural gas 

generation in the 2025 – 2040 timeframe. 

We are putting significant effort into building a strong 

foundation so that we are ready to unleash the full 

potential of SMRs, and projects in Canada are currently 

proceeding through three streams: 

p Stream 1 refers to near-term, grid-scale SMRs. Ontario 

Power Generation has announced that it is working 

towards a new grid-size SMR at its Darlington Nuclear 

Station by about 2028. 

p Stream 2 refers to the development of two advanced 

Generation IV SMR designs. This is being led by New 

Brunswick, and NB Power envisions technology 

demonstration at the Point Lepreau site in the early to 

mid-2030s. 

p Stream 3 refers to a new class of micro SMRs, with 

potential to replace the use of diesel for remote communities 

and mines. Canadian Nuclear Laboratories (CNL) 

launched an Invitation for Demonstration in 2018, to 

invite SMR vendors to propose demonstration projects 

for siting at an AECL-owned, CNL-managed site. 

Interview 



INTERVIEW 20 

| Figure 1 

Electricity generation by source, Canada 1990-2019. (Source: www.iea.org/countries/canada) 

| Figure 2 

Nuclear electricity generation, Canada 1990-2019. (Source: www.iea.org/countries/canada) 

At least, an adopted regulatory framework is 

necessary for SMRs. Until now, which milestones 

have been achieved and is there any international 

cooperation between governments and institutions 

on the subject? 

Canada has a world-renowned regulator committed to 

safety and open to innovation, as well as a comprehensive 

plan to manage nuclear waste in the long-term. This 

combination of enabling elements, coupled with our 

commitment to nuclear excellence, means Canada is 

poised to lead the world. 

The Canadian Nuclear Safety Commission (CNSC) 

offers optional pre- licensing engagement with potential 

applicants, as well as a pre-licensing vendor design review 

service, to help identify any significant barriers to licensing 

SMR technologies in Canada and thereby minimize potential 

impediments during the licensing process. 12 SMR 

design vendors are currently engaged with the CNSC in 

the vendor design process and are at various stages of 

review. 

On international collaboration: 

In 2019, the CNSC signed a memorandum of cooperation 

with the United States Nuclear Regulatory Commission 

that could support more efficient reviews of SMRs. 

The CNSC and the United Kingdom (UK) Office for 

Nuclear Regulation (ONR) recently (Oct 2020) signed two 

agreements to explore further collaboration and to more 

effectively regulate an ever-changing nuclear sector. 

A cornerstone of SMR technology to reach broad 

distribution as energy technology is serialization 

and the expected cost degression by number of 

installations. Are there already specific plans to 

realize this? 

Canada’s SMR Roadmap recognizes that as the technology 

matures, the cost of individual units will decrease. The 

Roadmap identifies several factors that will determine 

how quickly these costs decline, such as: 

p how many SMRs are built; 

p construction experience; and 

p the degree of standardization within SMR fleets. 

A major topic in discussions about nuclear power is 

waste management. What is the state of affairs in 

Canada particularly with regard to final disposal? 

The health, safety, and security of Canadians and the 

environment is the government’s top priority when it 

comes to regulating nuclear energy and materials. The 

Government of Canada is committed to ensuring that safe 

solutions are in place for managing radioactive waste now 

and into the future. 

Currently, all radioactive waste in Canada is safely 

managed in facilities licensed by the Canadian Nuclear 

Safety Commission (CNSC) – Canada’s independent 

nuclear regulator. 

The Nuclear Waste Management Organization 

( NWMO) is responsible for implementing Canada’s plan 

for the safe, long-term management of used nuclear fuel – 

including that created using new or emerging technologies. 

The Government of Canada is committed to continuous 

improvement with respect to ensuring that safe solutions 

are in place for managing radioactive waste. For this 

reason, Canada launched an open and transparent engagement 

process to modernize Canada’s radioactive waste 

policy. Between now and fall 2021, the Government of 

Canada is conducting a review of Canada’s Radioactive 

Waste Policy. As part of this process, officials are engaging 

with stakeholders and talking to Canadians, including 

Indigenous peoples, to ensure all voices are heard. 

What are the differences for waste management 

between existing nuclear power plants and the 

smaller scaled SMR based nuclear power plants? 

Will the SMR path require changes to the waste 

management strategy or will it be part of existing 

concepts? 

All radioactive waste in Canada is being safely managed 

according to international standards at facilities that are 

licensed and monitored by the CNSC. Depending on the 

waste type and other characteristics, owners of waste from 

SMR technologies may be able to use existing concepts or 

may need to implement new solutions for their radioactive 

waste. 

Author 


Head of Media Relations and Political Affairs 

KernD (Kerntechnik Deutschland e.V.) 

nicolas.wendler@kernd.de 

Interview 



“I am Personally Very Excited About 

Canadas’s Positioning as a Tier One 

Nuclear Power and also as a First Mover 

in Small Modular Reactors“ 

Interview with John Gorman ı President & CEO of Canadian Nuclear Association 

INTERVIEW 21 

The Canadian Nuclear Association represents an 

established nuclear industry which has decades of 

experience with nuclear technology. Can you give 

us a short overview of the nuclear sector in Canada? 

Let me start by saying that Canada is in a quite unique 

situation in terms of having both a vibrant nuclear ecosystem 

that is being fueled by the refurbishments of 

existing plants in our largest province of Ontario and in 

turn that is being used as a platform to do all sorts of 

innovation in Small Modular Reactors but also in other 

areas like medical isotopes. So, the combination of these 

two things, the healthy nuclear ecosystem and the 

innovation that we have going on in Small Modular 

Reactors is positioning Canada to provide climate change 

Small Modular 

Reactors will help us 

continue that track 

record and help others. 

solutions, the decarbonization 

of very important 

sectors of our economy 

here in Canada and by 

extension the ability to be 

a first mover in helping 

other nations around the 

world lower their GHGs. So, I am personally very excited 

about Canadas’s positioning as a tier one nuclear power 

and also as a first mover in Small Modular Reactors. 

In terms of actual statistics, we are a tier one nation 

being in this business for more than sixty years, with a very 

respected regulator and a highly respected track record in 

terms of the efficient and safe operation 

of nuclear plants. We currently 

have 12 different SMR technologies 

being evaluated and going through 

the review and licensing process in 

Canada making us a world leader in 

terms of the number of technologies 

and the speed with which we are developing them. CANDU 

technology is deployed in seven countries around the 

world and is still very actively involved in existing markets 

and developing markets. A great example of that is 

Romania, where they are very likely going to refurbish 

John Gorman 

Retiring coal in Ontario 

became and still is north 

Americas single largest 

carbon reduction initiative. 

President & CEO of Canadian Nuclear Association 

John Gorman is President & CEO of Canadian Nuclear Association, past President 

& CEO of the Canadian Solar Industries Association (CanSIA) and a Director on the 

board of the Energy Council of Canada (ECC). John served as Canada’s Designate 

to the International Energy Agency’s Executive Committee (PVPS) and was a 

Founder of the Canadian Council on Renewable Electricity (CanCORE). He’s using 

this experience to secure a leading role for nuclear energy at the heart of Canada’s 

energy transition. Before joining CanSIA, he was the Senior Vice President of 

Empower Energies, an innovative, global integrator of energy systems. He has 

served as a director on the boards of numerous community and corporate 

organizations, including one of the nation’s largest electric utilities. John has been 

recognized as one of Canada’s CLEAN50 and is the recipient of the “40 Under 40” 

business award for excellence in business practices. He was awarded the 

designation of Climate Project Ambassador by Nobel Laureate Al Gore in 2008. 

their two existing CANDU units and complete the 

construction of two additional units. So, Canada while 

being a smaller nation is a world leader in nuclear and we 

have accomplished some amazing things here from a 

climate perspective which I am eager to talk to you about 

and Small Modular Reactors will help us continue that 

track record and help others. 

You already mentioned the refurbishment programs. 

As I know of this is a quite unique feature, 

partially after long term shut downs. To understand 

this process, what determined the decisions about 

the refurbishment in both cases, i.e., the shut 

downs earlier and then the refurbishments and 

long-term operation later? 

This is an amazing story, that I hardly ever get asked about, 

so I am pleased to talk about it. Let me start with the punch 

line. Ontario, the largest province in Canada decided in the 

early 2000s to phase out all of our coal fired electricity. 

When we did that, coal fired electricity was providing 

about 25 % of Ontarios electricity, it was creating smog 

days and health problems and obviously 

emitting a lot of emissions. We replaced 

89 % of that coal fired electricity by 

bringing back online two units that had 

been shut down. So, in the process we 

were able to retire coal very quickly and 

retiring coal in Ontario became and still is 

north Americas single largest carbon reduction initiative. 

That’s the punch line. More specifically in 1997 Ontario 

Hydro, the utility, and the government made the decision 

to shut down two of our units because there was no 

demand for this electricity, there was a surplus. But by the 

Interview 

“I am Personally Very Excited About Canadas’s Positioning as a Tier One Nuclear Power and also as a First Mover in Small Modular Reactors“ ı John Gorman


INTERVIEW 22 

early 2000s supply had become tight, we needed more 

electricity and at the same time we made the decision to 

phase out coal fired electricity. We addressed both of those 

issues by restarting four units and subsequently made the 

decision to refurbish a number of our units. We are likely 

going to close down two of them in the mid-2020s but we 

will continue to operate the majority of the 18 units in 

Ontario. So, this is the story: surplus of generation in 1997 

made the decision for shut downs, then as more generation 

was needed and the phase out of coal was decided we 

brought them back on and we undertook this refurbishment. 

At this moment the refurbishment is the single 

largest infrastructure project in Canada. It is a 26-billiondollar 

refurbishment that is taking place over ten years 

and it is employing a lot of people and driving a lot of 

innovation. 

This brings me to a follow-up question: when I 

remember the discussions, we had in Germany 

about longer operation of nuclear power plants in 

2009 and 2010 there was a fierce opposition of the 

green party and of environmental organizations. 

Were there discussions of that kind and organizations 

parties or movements opposed to the 

refurbishment of nuclear power plants in Canada? 

There are certainly detractors of nuclear power in Canada. 

We continue as an industry globally and in Canada to be 

exposed to that sort of stigma and misinformation and not 

fact-based attitudes towards nuclear. But at the end of the 

day Canada has an outstanding record in terms of the safe 

operation and managements of its fleet. Canadians 

recognize that we are a world leader 

in nuclear power and clearly in the 

end the arguments and support in 

favor of refurbishment outweighed 

the detractors. Our country is very 

large, there are ten different provinces 

which are responsible for their own electricity supply so it 

becomes a very regional discussion rather than a national 

discussion. This might be a key difference between Canada 

and Germany. There is one thing that we know for certain: 

the more people know about nuclear the more supportive 

they are. In the provinces where we do have nuclear power 

like New Brunswick or Ontario or in Saskatchewan where 

there are uranium operations, these regions are very comfortable 

with nuclear or at least much more supportive 

than other provinces. 

Nuclear technology is not just about nuclear power 

plants, there are also very important other sectors. 

One of them is isotope production for many 

purposes including medical ones. In 2018 a major 

production facility in Canada that was important 

globally, the NRU reactor, was taken out of production 

and important capacity was lost. How was 

it compensated for or was it compensated for? 

It has been compensated for in a very interesting way. 

Firstly, the NRU had to be taken down because it served its 

lifespan. But we continue to have radioisotope production 

in our existing conventional power reactors and in other 

research reactors as well as particle accelerators such as 

TRIUMF and Canadian Light Source 

in western Canada. Despite the end of 

operation of NRU, we still have other 

research reactors and particle accelerators 

that are fulfilling that need. 

However, it has also spurred real 

The more people know 

about nuclear the more 

supportive they are. 

innovation here in Canada using our existing CANDU 

reactors. So, what we are seeing is that our two largest 

operators, Bruce Power and Ontario Power Generation 

have partnered with companies in the private sectors such 

as BWXT and isoGEN to produce isotopes from conventional 

reactors. This is really fascinating. There is no need 

to interrupt the operation of the units in any way. Ontario 

Power Generation and BWXT are beginning to produce 

Molybdeneum-99 at the Darlington Nuclear Association 

and Bruce Power, BWXT and Isogen similarly are beginning 

to produce Lutetium-177 for cancer therapy. At the 

same time, we continue to produce a large portion of the 

worlds supply of isotopes through our other assets. This 

includes more than 70 per cent of the global supply of 

Cobalt-60 and about 60 per cent of the world market for 

Iodine-129 is produced here as well. We have adapted and 

used innovation to replace the isotope production that was 

shut down. 

Let’s get back to power, the major question for 

many countries nowadays given all the climate 

discussions and climate targets. What is the longterm 

perspective for nuclear power in Canada and 

how is it included in Canadian or provincial energy 

and climate strategies? 

The long-term perspective for nuclear power in Canada is 

extremely bright for the reasons we have already spoken 

about. The refurbishment of our CANDU power plants in 

Ontario is the largest infrastructure program in Canada. It 

is going to keep those plants operating well into the 2060s 

and they are providing 15 per cent of Canadas clean 

electricity and a healthy nuclear ecosystem 

that is the foundation for other work that we 

are doing in Small Modular Reactors and 

isotopes. With this very strong foundation of 

the refurbishments going on with a large work 

force and innovation we have become a first 

mover in Small Modular Reactors. The government has 

started funding a number of the SMR-technologies that are 

under review and licensing and we expect to see more 

funding announcements in a short number of weeks 

coming. We also have an extraordinary level of coordination 

between government and industry and the provinces 

in the development and deployment of Small Modular 

Reactors. And this is quite exceptional and exciting: four of 

our provinces have signed a Memorandum of Understanding 

on the development and deployment of SMR. The 

federal government has come out and identified nuclear as 

being needed and essential for net zero in 2050, our 

national goal. So, we have both the federal government 

identifying nuclear as being essential to reaching net zero 

2050 and four provinces and their utilities who have 

agreed on a business plan for the development and deployment 

of SMR in their regions. When you combine this with 

our very progressive regulator, the Canadian Nuclear 

Safety Commission, which is very well suited to evaluate 

and work with innovative technologies much more so than 

some of the very prescriptive regulators we see in other 

places, it really becomes a competitive advantage for us. 

In fact, when you look at Canadas commitment around 

climate change which is very aggressive with the objective 

The federal government has come 

out and identified nuclear as being 

needed and essential for net zero 

in 2050, our national goal. 

of net zero in 2050 where 

nuclear is acknowledged as a 

key element of that energy 

plan and we have both a long 

term set of operating assets 

producing 15 per cent of our 

Interview 



Advertisement 

INTERVIEW 23 

electricity and a world leading advantage on the development 

of SMR, so the long-term perspectives of nuclear in 

Canada are assured. 

To realize the opportunities that exist with SMRs 

regulatory issues are quite important. They need 

certain adaptations compared to larger units and 

apparently this is working well in Canada as I can 

conclude from what you said. But is there also work 

going on to achieve some standardized regulations 

on SMR designs that are in the pipeline, are you 

cooperating with the US and the UK and maybe at 

some point with the European Union too because 

there probably soon will be an international market 

for this type of plants. 

You identified one of the most important issues here. 

Globally, to realize the benefits of SMR will need some 

standardization in terms of regulation. As you know this is 

a departure from a long history of nuclear power being a 

very nationally driven sector. Each country focused on a 

particular type of technology and set up a regulatory 

framework for this technology. Canada is a good example 

for this with its CANDU- technology. Of course, SMR 

depend on being mass produced and manufactured 

in manufacturing settings, making it more of a product 

and commodity. And because of their smaller size these 

units cannot afford the regulatory expense of needing to 

be certified in every country that they enter into. So, 

finding regulatory harmonization is key to SMR success 

going forward. What we have done here in Canada as the 

Canadian Nuclear Association is to begin working with our 

sister organization in the US, the NEI, and we have set up a 

US-Canada regulatory task force that is looking at these 

issues. But more importantly our regulators, the CNSC 

here in Canada and the NRC in the United States have 

signed a Memorandum of Cooperation and they are 

working on regulatory harmonization. So, we recognized 

the need here in north America for this standardization. At 

the same time, we have reached out to the Nuclear Industry 

Association in the UK and we are working with them as do 

our governments on these same issues. We have now 

signed a Memorandum of Understanding with our 

counter part in Europe, Foratom, and we will be talking 

about similar issues. But right now, the most developed 

push on this front is between Canada and the United States 

and has started with the UK and we hope to expand this to 

Europe as well. 

Is this the major aspect of the MoU with Foratom or 

are there other objectives too? 

There are other objectives as well. Firstly, the nuclear 

cooperation between Canada and Europe goes back for 

decades and specifically Canadian CANDU reactors have 

been in service in Romania for nearly thirty years. So, this 

MoU at the highest level addresses the need for greater 

dialogue and the exploration of the role of nuclear in 

effective environmental stewardship and a subtext to that 

would be this work that we have to do in rationalizing 

regulation around SMR. But the MoU has essentially three 

components to it: one is around advocacy and trying to 

advocate for more explicit inclusion for nuclear energy in 

Canada and the EU and that includes the idea of sustainable 

finance, taxonomy which I know that the European Union 

is grappling with right now. The second point is that we 

Interview 



INTERVIEW 24 

want to support innovation, particularly in SMR and 

advanced reactors which is something we flagged in the 

MoU and the regulatory work also falls into that. And we 

also want to find initiatives where we can work together to 

promote nuclear as a clean source of electricity that is 

needed for climate goals. 

But what I wanted to say about this idea of taxonomy 

and that nuclear is clean and the importance of that: the 

nuclear industry in Canada 

The nuclear industry in Canada like in 

other nations has had to work very 

hard with stake holders and policy 

makers to explicitly acknowledge 

nuclear power as clean energy and 

we have succeeded in that in Canada. 

like in other nations has had to 

work very hard with stake 

holders and policy makers to 

explicitly acknowledge nuclear 

power as clean energy and 

we have succeeded in that 

in Canada. So, recently just 

before Christmas the federal 

government explicitly identified 

nuclear as clean and essential to net zero 2050. And 

for us this has been important as we see in this increasingly 

carbon constrained world all of the policies and 

funding programs are increasingly directed toward clean 

technologies. We worked very hard for that and I am 

hoping that we can share some of the experiences and 

lessons that we learned here in Canada around this issue 

with Europe through our collaboration with Foratom. 

A last time back to the SMR projects: How far advanced 

are the projects trying to demonstrate the 

feasibility of new kinds of reactor designs? 

SMR are going to enter the market in Canada much sooner 

than people expect. Our largest utility, Ontario Power 

Generation, has announced that it will be net zero by 2040. 

But as part of that it will connect its first SMR at its Darlington 

Facility in 2028. SaskPower, Saskatchewan Power, is 

working in partnership with them to roll out multiple units 

in Saskatchewan with the same technology right on the 

heels with OPG. And we have other technologies, including 

very small reactor technologies, that are projecting that 

they will be in the market even sooner, by 2026. There is an 

amazing story here about the application of very small reactors 

in a number of Canadas most important sectors. The 

market demand in Canada for very small reactors is about 

5.3 billion Dollars between 2030 and 2040. And much of 

that market demand is in the mining industry using SMRs 

for their high temperature heat, to generate electricity but 

also to produce hydrogen. Many of these SMRs are going to 

be used in heavy industry like cement and steel, fertilizer 

production, in the oil sands, which is such an important 

part of our economy. These SMRs are going to be used to 

generate high temperature steam to clean up the extraction 

process for oil and gas. 

So, Canada is not only a first mover in SMRs but it has a 

set of industries that are able to take advantage of the 

unique capabilities of SMRs while decarbonizing those 

sectors and ensuring that Canadas natural resource sector 

and the materials that we produce are going to be 

competitive in this increasingly carbon constrained world. 

It is really a beautiful dynamic that we have here in Canada 

of being able to develop a handful of SMR technologies 

that are going to be tailor made to address the particular 

GHG reduction issues in our industries. And our hope of 

course is that we will be able to use those technologies to 

help other nations decarbonize their heavy industries and 

natural resource sectors so that we can contribute to the 

world moving to a low carbon economy. 

And finally, I want to come to nuclear waste 

management. What are Canadas plans for waste 

management? 

Readers of atw surely will know that the nuclear industry 

is a very responsible manager of nuclear waste and that the 

facts on spent fuel are actually quite a positive story. We 

are the only energy generating sector that is entirely 

responsible for the all of the byproducts that it produces 

and we prepay for its safe management 

and storage. We don’t emit 

pollution to the environment and 

we produce so little spent fuel 

because uranium is so power dense. 

We have been operating for 

60 years providing 15 per cent of 

the nations electricity and we 

barely fill up a few hockey rings to 

the floor boards with spent fuel. It 

is exceptionally well managed, no one has ever been 

harmed, let alone killed by spent fuel. If you look at our 

entire life cycle from uranium mining to storing the spent 

fuel and all of our byproducts, we have the lowest carbon 

footprint of any electricity generating source, only wind is 

comparable. We have an amazing story to tell on that front 

that people don’t understand. 

But we also recognize that we need a permanent 

solution for storing the waste. We have been managing the 

waste exceptionally well to this point but especially in 

Canada where we are extending the life of our nuclear 

plants for another 40 years and because of the advent of 

SMR we need a permanent storage for the waste. So, there 

are currently two communities, two land-locked areas that 

have been short listed for a deep geological repository, 

South Bruce in southern Ontario and Ignace in northwestern 

Ontario and we have a nuclear waste management 

organization that is overseeing the site selection for 

this area. We are going to follow the example of Finland 

here which is on track to have their DGR by 2023 and we 

are going to continue managing our spent fuel until that 

deep geological repository is completed. Another thing 

that we are excited about is that a number of the technologies 

that are reviewed and hopefully licensed here in 

Canada will also be reusing the spent fuel from the CANDU 

reactors as their fuel which adds some additional avenues 

for properly storing or using the spent fuel. 

Interviewer 


Head of Media Relations and Political Affairs 

KernD (Kerntechnik Deutschland e.V.) 

nicolas.wendler@kernd.de 

Interview 



Nuclear Power is Dead, 

Long Live Nuclear Energy! 

Simon Wakter 

The supposed demise of nuclear power has long been asserted by those opposed to the technology. But as the world 

struggles to meet the Paris Agreement climate goals of limiting global temperature increase by 1.5 °C to 2 °C compared 

to pre-industrial levels, neither the historic contribution nor the important future role of nuclear energy should be 

ignored. Nuclear is an indispensable tool to meet the dual challenge of meeting an increasing energy demand while 

phasing out fossil fuels. To paraphrase the speech of Robert Cecil at the final meeting of the League of Nations – nuclear 

power is dead, long live nuclear energy! 

Many countries have made pledges to decrease emissions 

or set net zero goals by the year 2050. This leaves just 

under 30 years to dramatically reduce emissions, while 

global energy use is expected to continue rising. As pledges 

are often phrased in terms of reductions in relation to 1990 

emission levels, it also means that just over 30 years have 

passed since the ‘benchmark’ year. In those 30 years, the 

share of fossil fuels in both electricity and total energy 

consumption has remained virtually unchanged, at around 

65 percent and 85 percent respectively. The share of 

nuclear energy in electricity production today is around 

ten percent, a drop from a high of 17.5 percent in 1996. The 

drop in nuclear production is only in terms of the share of 

total production – nuclear electricity production has 

actually increased in absolute terms, but world electricity 

demand has roughly doubled in the same period. Total 

energy demand has increased by about 60 percent. 

Higher energy and electricity consumption is correlated 

with higher development and human welfare indicators. 

The increased access to and use of electricity has contributed 

greatly to the improved standards of living for 

hundreds of millions of people. But many people still lack 

access to electricity and much of the worlds electricity and 

energy consumption is still fossil fuelled. As has become 

abundantly clear, energy production must increase but 

must also be clean. 

Globally, the combined share of low carbon technologies 

amounts to approximately 35 percent of total 

electricity production. Nuclear accounts for 30 percent of 

this low carbon electricity, second only to hydro power’s 

46 percent. In advanced economies, nuclear energy 

supplies 40 percent of low carbon electricity. 1,2 Within the 

EU, just over half of electricity is produced from low carbon 

technologies and nuclear supplies almost half of this clean 

electricity. 3 

The world now faces the enormous, twofold challenge 

of transitioning to clean energy while meeting the increase 

in energy and electricity demand. 

| Figure 1 

Low carbon electricity generation in advanced economies in 2018. 1,2 

added on top of the daily trials of coronavirus lockdown. 

The lack of electricity, frequent blackouts and interruptions 

to internet and running water made working or 

studying from home virtually impossible. 

In Japan, a cold spell coupled with an already tight LNG 

market in Asia brought power prices to record highs. 

Intraday power prices reached over ¥250/kWh, or roughly 

€2/kWh, with spot prices topping out at around 

¥155/kWh, or €1,20/kWh. 

In Texas, arctic temperatures brought electricity 

demand surging toward all-time highs and prices topped 

out at over $9,000/MWh, or €7,700/MWh. When power 

plants (primarily gas power plants) dropped from the grid 

due to the cold, grid operators initiated rotating outages 

which then turned into lasting blackouts for millions of 

peoples. 

Both in Texas and in Japan, utilities as well as consumers 

have been hit by the record breaking prices leading to 

extraordinary corporate and personal financial difficulties. 

25 

SERIAL | MAJOR TRENDS IN ENERGY POLICY AND NUCLEAR POWER 

Energy enables modern lives 

Access to affordable energy is the foundation of modern, 

civilised societies. The ability to use energy when and 

where it is needed enables almost every other human 

activity. This has been illustrated and reinforced by events 

during the past year. In Libya, already strenuous conditions 

have worsened through prolonged power outages 

Electricity is key 

The key to solving a large part of the decarbonisation challenge 

is electricity. Dramatic cost reductions in wind and 

solar production has redrawn the map and enabled a large 

scale roll out of clean electricity only ever before seen in 

the nuclear energy programmes of countries such as Sweden 

and France. 

1 Nuclear Power in a Clean Energy System, International Energy Agency (IEA), May 2019 

2 European Commission Joint Research Centre, Technical assessment of nuclear energy with respect to the ‘do no significant harm’ criteria of Regulation (EU) 2020/852 

(‘Taxonomy Regulation’), Petten, 2021, JRC124193 

3 Eurostat, Electricity production by source, EU-27, 2019, https://ec.europa.eu/eurostat/statistics-explained/index.php/Electricity_generation_statistics_–_first_results 


Nuclear Power is Dead, Long Live Nuclear Energy! ı Simon Wakter


SERIAL | MAJOR TRENDS IN ENERGY POLICY AND NUCLEAR POWER 26 

Electrification also brings with it great potential for 

improvements in efficiency. For example, the electrification 

of transportation through electric vehicles offers 

significant efficiency improvements compared to fossil 

fuelled cars. 

Large scale production of hydrogen through electrolysis 

enables the decarbonisation of several industry processes, 

such as iron production. Direct electrification through 

Electric Arc Furnaces, EAF, enables fossil free steel 

production. 

It’s a power grid, not an energy grid 

Electrification is a versatile tool for decarbonisation, but 

places high demands on the power grid. Analysing and 

designing systems based on the required energy on a yearly 

basis is not sufficient. 

Before transmission of power through alternating 

current was discovered by Nikola Tesla at the end of the 

19 th century, so called flatrod systems (German: Kunstgestänge 

or Stangenwerk) were used to transfer power. 

Flatrod systems, made up of timbers which were tied or 

joined together, made it possible to transfer power both 

horizontally and vertically over distances up to a few 

kilometres. 

Similarly to the flat rod system swinging back and forth, 

alternating current is based on the current constantly 

changing direction. Just like the flatrods, it is the oscillations 

that transmit the power. In Europe, the oscillation 

takes place 50 times per second and must always stay at 

this constant frequency. A multitude of instrumentation 

and control systems are in place to make sure the system is 

always balanced – the production and load must always be 

equal. 

The economic market for trading, called the power 

market, is not really a market for power but rather for 

energy. Energy becomes a commodity to be produced, 

distributed and consumed. This step away from the 

physical concept of energy enables competition but also 

brings difficulties. 

In order to function properly, and in turn enable the 

market, the power grid also requires balancing and 

ancillary services. Such services may consist of inertia, 

reactive power or short circuit power, all of which have so 

far been provided largely for free by large generators such 

as nuclear power plants. While markets exist for some 

services, e.g. for frequency reserve measures, it is likely 

that new markets for such services will be necessary in the 

future to ensure the functioning of the power system. 4 

Nuclear can already provide many of these services 

today and with the right incentives it is possible to expand 

the services, e.g. through integrating thermal storage with 

molten salt in advanced reactors. 

It’s not all electricity 

Electrification is key to decarbonisation, but does not 

paint the full picture. Some sectors, e.g. energy-intensive 

industry and heavy-duty transportation (such as long-haul 

aviation, maritime shipping and some road freight), are 

| Figure 2 

Global greenhouse gas emissions by sector. 4 This is shown for the year 2016 – global greenhouse gas emissions were 49.4 billion tonnes CO 2 eq. 

4 Ritchie, H.; Our World in Data – Sector by sector: where do global greenhouse gas emissions come from? https://ourworldindata.org/ghg-emissions-by-sector 




more challenging to decarbonise and will require greater 

effort and novel approaches. These sectors, heavy industry 

and heavy-duty transports, make up almost one-third of 

global carbon emission. 

Iron and steel production makes up seven percent of 

greenhouse gas emissions. The emissions stem from two 

sources – from the fossil fuels used to heat and power the 

process, and from the coking coal used as raw material in 

the reduction process itself. Low carbon energy can replace 

the fossil fuels used to power the process, and clean 

hydrogen can replace the coking coal used for the reduction 

of oxygen in the iron oxide. Hydrogen is also an important 

feedstock in ammonia and fertilizer production as well as 

for refining fossil fuels, biofuels or plastics. This hydrogen 

demand, today around 70 million tons per year, is currently 

met almost exclusively by production from fossil fuels. 

The production of cement produces around three 

percent of global greenhouse gas emissions. Again, the 

emissions stem from two sources. In this case roughly 

60 percent of emissions are inherent to the calcining 

process itself, while the remaining 40 percent arise from 

the use of fossil fuels for heating the production process. 

Electrification and fossil free fuels can replace the fossil 

fuels, but emissions inherent to the calcining process will 

require carbon capture technologies. 

A large part of transportation can most likely be solved 

through electrification, but heavy-duty transportation will 

require higher density energy storage or fuels. This could 

be in the form of hydrogen, ammonia or other electrofuels 

such as synthetic hydrocarbons which can be made 

through the Fischer-Tropsch process, combining carbon 

monoxide (from carbon capture) and hydrogen into liquid 

hydrocarbons. 

Energy use in buildings is another major sector, behind 

almost one-fifth of emissions. Although electrification is a 

major part of the solution, a large share of the property 

stock relies on fossil gas for heating. Replacing gas boilers 

with ground source or air source heat pumps could prove 

prohibitively expensive – especially for those in energy 

poverty, already struggling with a “heat or eat”-dilemma. 

Existing grids, built for gas heated buildings, would 

struggle to serve the increased power demand during cold 

or hot spells. Hydrogen, either replacing or mixed into existing 

gas pipelines, and district heating have both been 

proposed as solutions. 

The scale of energy use in buildings is often overlooked. 

For example, final energy consumption for heating in 

German residential buildings is roughly equal to the total 

German electricity production, approximately 560 TWh 

per year. Since 95 % of this heating demand is met with 

fossil fuels, heating the country’s 40 million homes 

produces almost ten percent of Germany’s greenhouse gas 

emissions. Even partially meeting this energy demand 

with clean hydrogen would require an extraordinary 

amount of electricity for electrolysis – hydrogen from fossil 

methane is not carbon neutral, especially when accounting 

for flaring and fugitive emissions – meaning electrification 

and district heating may prove to be more sensible 

solutions. Nuclear CHP plants could provide cities with 

both electricity and district heating, which is already done 

at several locations today. District heating reactors, that 

produce only heat and not power, are also being developed 

and constructed. 

All in all, industry and transport together with energy 

use in buildings make up almost 60 percent of global 

emissions. Nuclear is an important tool in these “hard-toabate” 

sectors. 

Small solutions to big problems 

A new wave of modern small and advanced modular 

reactors are currently being designed, licensed and built 

all over the world. These reactors have increased passive 

safety features, reduced or no emergency planning zone 

and significant potential for cost savings. 

To compensate for lack of economies of scale, otherwise 

associated with larger reactors, smaller reactors take 

advantage of simpler construction principles, modularity 

and standardisation to decrease cost. The smaller size also 

decreases initial capital expenditure, construction time 

and overall risk. This creates a feedback loop which works 

to decrease the overall cost of capital, which for traditional 

large scale reactors can account for up to 70 percent of 

total costs. 

More is more when it comes to heat output 

Many advanced reactors work at significantly higher 

temperatures than conventional reactors. Where today’s 

boiling and pressurised water reactors work at temperatures 

around 300 °C, advanced reactors cooled with 

molten lead, sodium or gas work at temperatures between 

500 and 700 °C. This means higher efficiencies and opens 

up a range of new applications. 

Advanced nuclear reactors, providing high temperature 

heat and electricity now become an attractive option for 

hydrogen production, process heat, district heating, 

desalination and carbon capture through direct air capture 

(DAC). Nuclear energy can be integrated across the 

manufacturing process in many applications, e.g. for 

production of iron and steel where high temperature 

electrolysis, electricity production and large amounts of 

high temperature heat can dramatically reduce emissions 

and improve efficiencies. 

Coal power remains largely unthreatened as the world’s 

main source of electricity production, with global output 

increasing to over 4,630 TWh in 2020 5 . One solution, as 

explored in an article by Qvist et al. 6 , is “retrofit decarbonisation” 

– a term which includes repowering of coal 

units with low-carbon energy technology. The prospect of 

| Figure 3 

Steam temperature comparison, nuclear and coal power plants. 6 


5 Ember, Global Electricity Review 2021, https://ember-climate.org/project/global-electricity-review-2021/ 

6 Qvist, S.; Gładysz, P.; Bartela, Ł.; Sowiżdżał, A. Retrofit Decarbonization of Coal Power Plants—A Case Study for Poland. Energies 2021, 14, 120. 

https://doi.org/10.3390/en14010120 





advanced reactors capable of high temperature output, 

suitable for existing coal powered steam turbines, and the 

fact that more than half of the world’s 2,000 GWe coal fleet 

is less than 14 years old combine to create a compelling 

argument. 

Integrating and reusing the existing site, equipment 

(cooling water systems and steam cycle) and grid connection 

could lower upfront capital costs by 28 – 35 percent 

and levelized cost of electricity by 9 – 28 percent compared 

to a greenfield installation. 

Standardisation, harmonisation, cooperation 

To realise the potential of small and advanced modular 

reactors it is essential to avoid unnecessary, countryspecific 

design modifications or changes to documentation. 

Policymakers and regulators must work to ensure 

stability and predictability in the licensing process as well 

as to increase international harmonisation of licensing 

requirements. 

Redesigning SMRs for each country would quickly 

become prohibitively expensive, which means licensing 

regimes need to be performance-based rather than 

prescriptive. Licensing should also be risk-informed and 

technology-inclusive. In the cases where that is difficult or 

not possible it is important that regulators agree on 

terminology and definitions, possibly through a taxonomy 

of licensing requirements. One example is the definition of 

active and passive systems, which has varying definitions 

between different countries and different organisations. 

Increasing standardisation and harmonisation through 

international cooperation is a low cost, no-regrets option 

for countries wishing to expand the use of nuclear energy. 

Enabling nuclear energy 

Nuclear energy is a flexible solution which can help solve 

many challenges – providing electricity and heat for 

several applications ranging from industrial process heat, 

through hydrogen production to carbon capture and 

production of electrofuels. Nuclear also provides firm 

power and grid stability, aiding in the integration of 

variable renewable energy sources. 

In addition to contributing to the historic and future 

decarbonisation of energy use in the west, expansion of 

nuclear energy is a promising solution for economies in 

transition and developing economies seeking to improve 

living standards while reducing greenhouse gas emissions. 

Over 30 “nuclear new-comers” have concrete plans to 

develop nuclear energy projects in the coming decade. 

Recent research by Kenton de Kirby and Jessica Lovering 

offer important insights and lessons on how to enable the 

success of nuclear energy in emerging markets. 

In their report 7 , de Kirby and Lovering find that local 

opposition to projects in emerging markets differs from the 

anti-nuclear movement of the 1970’s which, in highincome 

countries, has protested nuclear on ideological and 

absolutist grounds. The authors warn against projecting 

fundamental anti-nuclear sentiments onto activists in 

newcomer countries. Instead, local opposition is largely 

based in a worry about livelihoods, lack of local economic 

benefit and government corruption as well as the government’s 

inability to respond effectively in the event of an 

accident. 

To gain public trust and consent, stakeholders must 

establish strategies and take concrete action to improve 

transparency, involve the local community and work to 

understand activist’s concerns – all while addressing 

perceived risks and building trust in regulators and 

relevant institutions. The report goes on to offer concrete 

ideas and best practices for effective engagement with 

local communities. 

Nuclear power is dead, 

long live nuclear energy! 

From harmonisation and standardisation of licensing 

requirements in established nuclear energy countries to 

stakeholder engagement in emerging economies, nuclear 

energy (like other clean energy technologies) must be 

enabled through proactive work from politicians, policymakers 

and international institutions. 

75 years ago, in the spring of 1946, Robert Cecil 

participated in the final meeting of the League of Nations 

in Geneva. Lord Cecil was one of the architects of the 

League and participated during the creation of the United 

Nations. He ended his final speech at the meeting with the 

words: “The League is dead, long live the United Nations.” 

Whether the world successfully eradicates global 

poverty while managing climate change will be largely 

determined by the events in emerging markets. Nuclear 

energy is an indispensable tool to meet the dual challenge 

of increasing energy consumption while phasing out fossil 

fuels. Just as the League was succeeded by the United 

Nations, formed to meet new challenges, so our view of 

nuclear must grow to meet the challenges that lay ahead. 

To paraphrase the speech of Robert Cecil – Nuclear power 

is dead, long live nuclear energy! 

Author 

Simon Wakter 

Expert Advisor, Energy 

Simon Wakter is a nuclear energy engineer working as Expert Advisor in energy 

systems at the consultancy firm AFRY, with experience from technical consultancy in 

nuclear safety and licensing as well as from advising on different projects ranging 

from SMRs to hydrogen. Mr. Wakter is also a board member of the Swedish Nuclear 

Society and one of the founders of the Swedish Ecomodernists. 

7 de Kirby, K; Lovering, J. A Socially Sustainable Future for Nuclear Energy in Emerging Markets, 2021 

https://thebreakthrough.org/issues/energy/socially-sustainable-nuclear-in-emerging-markets 




Europe on the Road to a Major Disaster 

When Physics and the Laws of Nature Are Disregarded, 

a Rude Awakening Looms 


Introduction The European electricity supply system is undergoing a radical upheaval. What is essential in terms 

of climate protection policy is leading to the interconnected system becoming increasingly fragile, because the approach 

which is being adopted is non-systemic. Instead of sound basic knowledge, it is wishful thinking and knee-jerk reactions 

which are determining the approach, and this could end in the greatest catastrophe since World War II. 

We can still turn away from this disastrous 

route. This would require rapid 

and decisive political action, but there 

is no evidence of this at present. A 

systemic conversion of the European 

electricity supply system into robust 

energy cells would have to be initiated 

immediately to reduce the looming 

susceptibility to failure. From a 

technical point of view, this would not 

be a problem, since the necessary 

knowledge is available and this 

conversion could be undertaken while 

the system is in operation. 

The greatest obstacle here is the 

fact that we have so far successfully 

thought in terms of large-scale 

technology, and this would have to be 

supplemented by complementary 

complexity and networked thinking, 

and adopted as the maxim. This 

requires appropriate framework conditions. 

The current route is pointing 

more in the opposite direction, however, 

towards centralization, but this 

makes it impossible to manage a system 

which is becoming increasingly 

complex. 

The electricity supply is our most 

important lifeline, without which our 

modern society could be destroyed 

within only a few days. We ought to 

prevent this from happening. 

On January 8, 2021 we experienced 

the second most serious 

major disruption so far in the 

European power supply system 

(ENTSO-E/RG CE – Regional Group 

Central Europe). The consequences 

were very minor compared to the 

first one on November 4, 2006. On 

that occasion, around 10 million 

households in Western Europe had 

to be disconnected from the grid 

within 19 seconds to prevent a 

pan-European blackout. This time, 

those affected were “only” large 

commercial customers in France 

and Italy which had contractually 

agreed to be disconnected should 

such an incident occur. The precautionary 

and communication 

measures of the 43 European transmission 

system operators, which 

have continually been improving 

the situation since 2006, meant the 

disruption could be rectified after 

about one hour. Hardly anybody 

had expected yet another major 

disruption. Despite everything, 

nobody knows whether the security 

mechanisms which have been 

designed will also be effective when 

the next incident takes place. 

The worst case would be a pan- 

European electricity, infrastructure 

and supply outage, a so-called 

blackout, as is expected by the 

Austrian Armed Forces or the 

author, within the next five years. 

In the European interconnected 

system, the expenditures needed to be 

able to maintain grid stability have 

been increasing for many years. The 

Austrian bottleneck management 

costs, i. e., the expenditures to avert 

an imminent blackout, have ballooned 

from 2 million euro in 2011 to 

346 million euro. Instead of 2 interventions, 

interventions were necessary 

on 301 days within a few years. 

Although these expenditures fell 

slightly in 2019 and 2020, they are 

still far too high. This is primarily 

down to the fact that the system does 

not adjust to the framework conditions, 

which have changed considerably 

in the meantime, and also 

the necessary transition to renewable 

energy. 

| Figure 1 

ENTSO-E/RG CE – Regional Group Central Europe. 

Lack of storage systems 

and buffers 

Wind and sun are not always available, 

and there are sometimes significant 

deviations between forecast and 

actual production. In a system where 

the balance between generation and 

consumption has to be maintained for 

31,536,000 seconds per year, this is 

an enormous challenge, particularly 

since there is a lack of systemsupporting 

storage systems and 

buffers. This situation can only be 

remedied by large-scale power station 

interventions, but this does not represent 

a permanent solution and incurs 

high costs. In addition, the susceptibility 

to failure of the whole system is 

increasing because it is permanently 

under stress. 

Whereas in Austria around 

3,300 GWh of pumped storage capacity 

is theoretically available, the 

whole of Germany can muster only 

around 40 GWh. And there are no 

plans for expansion which are worth 

mentioning. With electricity consumption 

currently at 60 to 80 GW, 

Germany would not be able to cover 

even one hour of its own electricity 

consumption. Quite apart from the 

fact that this would not be technically 

feasible, because only around 11 GW 

of bottleneck power is available. In the 

whole of Europe, storage systems with 

a turbine capacity of around 47 GW 

are currently available, two thirds of 

this with a pumping option to refill the 

29 

ENERGY POLICY, ECONOMY AND LAW 


Europe on the Road to a Major Disaster ı Herbert Saurugg


ENERGY POLICY, ECONOMY AND LAW 30 

storage reservoirs when surplus 

electricity is available. This can cover 

or temporarily store only a fraction of 

European consumption. 

The issue of storage ranges from 

inherent to seasonal, which requires 

different technologies. The transition 

to renewable energy so far has disregarded 

the fact that conventional 

power stations have the storage 

integrated in the primary energy 

( nuclear fuel rods, gas, coal, oil), thus 

making it possible to balance the 

continual changes in consumption. 

But now we have increasing, and 

increasingly more difficult to forecast 

consumption, and volatile electricity 

generation at the same time. Two 

things which cannot be reconciled 

without appropriate storage systems 

and buffers. 

Power-to-X 

Power-to-X, especially the use of 

hydrogen, is deemed to be very 

promising for seasonal storage. In 

principle, it sounds very tempting, 

since an existing infrastructure would 

already be available - the gas grid. The 

fact that a number of big challenges 

remain to be solved is usually not 

mentioned. Least of all the costs. The 

announcement of a large wave of 

financial support triggered a goldrush 

mood and an avalanche of further 

announcements. It is to be expected 

that a gold nugget or two will indeed 

be found. But people should not really 

expect that a great breakthrough and 

widespread implementation will be 

possible within the next few years. 

What we do need are solutions that 

can be implemented rapidly, not only 

in 10 to 20 years’ time. On the other 

hand, we still know relatively little 

about the potential side effects of the 

water vapor which is released in huge 

amounts as the hydrogen is being 

reconverted to produce electricity. 

And even more attention needs to be 

paid to this aspect with the planned 

methanation, since we already know 

the effects here, because methane is 

significantly more harmful to the environment 

than CO 2 . 

Inconsistency 

The general principle is that there is 

no form of energy which would not 

have any side effects. Enormous 

resources are required for wind and 

PV systems as well, but people usually 

have a distorted perception of this, 

unfortunately. The individual system 

is small and manageable. But if one 

considers the actual performance and 

extends these considerations to cover 

| Figure 2 

Turbo-generator set of a thermal power plant. (Source: Foro de la Industria Nuclear Española) 

a period of one year, a very different 

picture emerges. The wrong way of 

thinking often leads to apples being 

compared with oranges, or to average 

values being used. But all that is 

relevant for the operation is the 

contribution that one specific type of 

energy generation can guarantee in 

order to maintain the necessary 

permanent balance. This means not 

calculated as a statistical average over 

the year, but plannable, reliable and 

constant. If that were to be done, one 

would very quickly recognize that it 

requires much more than simply a 

production plant. 

This is precisely the way of thinking 

that is necessary to be able to ensure 

the systemic restructuring of our most 

important lifeline. Our either/or 

thinking will not get us anywhere 

here. We need both/and thinking to 

master the challenges we are facing. 

CO 2 emissions can be significantly 

reduced with renewable energies, but 

at the same time we also need other 

elements in the system to be able to 

continue to guarantee the very high 

security of supply to which we have 

hitherto been accustomed. 

Instantaneous reserve 

Another technical detail which is 

hardly ever considered concerns 

the instantaneous reserve, i.e., the 

rotating masses of conventional power 

stations. When nuclear and coal-fired 

power plants are shutdown, these 

reserves are also disconnected from 

the grid on a grand scale. The gyrating 

masses of the synchronous generators 

play a key role for the frequency 

generation and maintenance, since 

mechanical energy is thereby continuously 

converted into electrical 

energy and vice versa without the 

need for controlling interventions. A 

purely physical process. They can also 

be thought of as large shock absorbers 

for load shocks, which have so far 

ensured that the operation of the 

European interconnected system has 

been so stable. These shock absorbers 

are now being removed and not really 

replaced, which makes the whole 

system more susceptible to failure. 

The instantaneous reserve is at the 

same time also an inherently available 

energy storage system, which can 

temporarily buffer any short-term 

energy surplus. The generated frequency 

of the alternating current 

therefore also always indicates 

whether there is a lack of power or 

a surplus of power in the system overall. 

IT-independent control interventions 

can therefore be specifically 

performed via the frequency, and the 

system overall kept stable. 

Implementation speed 

Approaches which utilize large 

system-supporting storage batteries 

and corresponding power electronics 

already exist, and are already being 

used in Southern Australia, Great 

Britain and now also in Texas, for 

example, to reproduce and compensate 

the instantaneous reserve. It 

is supplementary, however, and will 

never be able to replace the complete 

instantaneous reserve. Here again, a 

both/and mindset is crucial. In the 

ENTSO-E RG CE grid, these systems 

first need to be implemented on a 

grand scale, however. As is often the 

case, the sticking point is not the 

knowledge or the technology, but the 

implementation. This would have to 

take place at the same speed as the 

other measures are being taken. 

Germany is going it alone 

The biggest problem is that Germany 

in particular is taking the second step 

before the first: Conventional power 




stations are being shut down in 

large numbers without an equivalent 

replacement being available. The 

emphasis so far has been placed on 

the rapid expansion of wind and PV 

power stations or providing massive 

financial support for them. But what is 

missing here is the indispensable 

system adjustment, starting with the 

lack of storage systems and buffers, 

and continuing with the lack of 

trans mission possibilities, i.e., lines. 

In addition, the electricity no longer 

has to be distributed in a one-way 

system only, because those who 

were pre viously consumers have now 

increasingly become producers as 

well, i.e., so-called prosumers, and 

therefore there are also load flows in 

the opposite direction, for which the 

system and the protective devices 

were never designed. 

In Germany, it is also assumed, at 

least in the current planning documents, 

that in the future, electricity 

can simply be imported from its neighbors 

when needed. But somebody else 

might just have a thing or two to say 

about that. Because: Where is the 

electricity going to come from when 

these countries have already been 

importing electricity from Germany 

when they have had shortfalls? In 

addition, conventional power stations 

are being shutdown everywhere. And 

the idea that the wind will always be 

blowing somewhere is a myth which 

does not withstand scrutiny. Quite 

apart from the fact that the transmission 

infrastructure would still be 

needed, and this was never built for 

large-scale electricity exchange. The 

desire for Europe to be a single 

conductive sheet of copper is understandable, 

but bears no resemblance 

to reality and ignores physical framework 

conditions. 

Decentralized functional units 

Moreover, millions of tiny power 

stations and new actors can no longer 

be controlled using the centralized 

structure and logic which has previously 

been successful. What is 

required instead is an “orchestration” 

of this multitude of components and 

actors which, with the self-organization 

of a “swarm”, will then automatically 

play their part in ensuring the 

security of supply by having a view of 

the situation in the overall system 

which is accessible to all. This requires 

it be restructured into so-called robust 

energy cells, however, since the increasing 

complexity will not be 

manageable otherwise. For complex 

systems cannot be centrally controlled, 

they require decentralized autonomous 

units, where demand, storage 

and generation are balanced locally or 

regionally if possible, and not as at 

present, where problems are shifted 

around across a wide area. Crosssystem 

synergies (electricity, heat, 

mobility) must be used as well. The 

issue is therefore a holistic energy 

supply in cellular structures, which 

first requires a rethink in many places. 

Such an approach is not inconsistent 

with the previous large-scale 

system, which will still be required as 

before, since it will not be possible to 

supply large consumers such as large 

industrial enterprises or cities in other 

ways for some time yet. But these 

decentralized structures and functional 

units do enable us to enhance 

the robustness of the overall system 

bottom-up and while it is in operation, 

without interruptions. Cellular structures 

are not as efficient as the largescale 

system we have had to date, but 

this holds true only as long as there is 

no major disruption in the form of a 

blackout. In such a case, all previous 

gains in efficiency would be destroyed 

in a single blow and incredible societal 

damage would be caused. Resilience 

and robustness require redundancies 

and reserves, and are therefore generally 

in conflict with the efficiency 

mindset, which is driven mainly by 

economic considerations. 

No such thing as one-hundred 

percent security 

Moreover, there is simply no such 

thing as a failure-proof system, as the 

European transmission system operators 

stated clearly and unequivocally 

in their investigative report on the 

blackout in Turkey: “A large electric 

power system is the most complex 

existing man-made machine. 

Although the common expectation of 

the public in the economically 

advanced countries is that the electric 

supply should never be interrupted, 

there is, unfortunately, no collapsefree 

power system.” 

Increasing complexity 

We should therefore learn from 

nature, where all living things are 

organized in cellular structures. This 

has obviously been tried and tested 

and has survived through time. For 

what is being celebrated as a decentralized 

transition to renewable energy is 

currently anything but decentralized. 

The whole transition to renewable 

energy to date only works because of 

the existing centralized system with 

the requisite storage systems and 

buffers. The proposed smart grid and 

flexibilization measures also depend 

on a comprehensive, cen tralized IT 

network and thus on an increasing 

degree of complexity. Thus, in addition 

to the risk of cyber attacks, the 

result is additional, hardly noticed 

side effects. 

Complex systems 

Complex systems exhibit a number 

of unpleasant characteristics which 

cannot be managed with our linear 

way of thinking and machine logic 

which has succeeded so far. As the 

number of actors and the networking 

increases, so does the complexity and 

thus the dynamics, which we can 

observe on an ongoing basis, of 

course. We can hardly keep up. At the 

same time, the forecastability of the 

system behavior worsens because 

self-amplifying feedback processes 

are possible, as can currently be seen 

with the phasing out of coal power: An 

increasing number of power plant 

operators want to abandon coal early, 

because their operation is no longer 

profitable. At the same time, we have 

more or less run down the overcapacities 

which used to be available 

during the past 10 years, which means 

less and less scope for action remains. 

Phase-out of coal and nuclear 

power 

At the beginning of January 2021, 

those German coal-fired power plants 

which had strictly speaking been 

selected for early shutdown had 

already to go onstream again, because 

the demand could not be covered 

sufficiently well. If Germany sticks to 

its plans to phase out coal and nuclear 

power, which is currently firmly 

scheduled for the end of 2022, this 

will already give rise to critical 

windows in the coming months, 

where regional shutdowns to protect 

the system as a whole can no longer be 

excluded. It is irrelevant here whether 

it will nevertheless just work out 

in 99.99 percent of the time. The 

electricity supply system knows no 

leeway here. The balance must be 

safeguarded 100 percent of the time. 

There is a risk the system will collapse 

otherwise. 

Lack of basic knowledge 

It is unfortunately the case that in 

many fields and among most of 

the decision-makers, too, there is a 

lack of the most basic knowledge 

about the laws of nature, especially 

the laws of physics, and also a lack 

of technical know-how to understand 






the implications of often ill-considered 

decisions. This situation is now 

being compounded by the lack of 

knowledge on how to deal with 

complex systems, since this is not part 

of our universal basic education. 

Characteristics of complex 

systems 

One further characteristic of complex 

systems is that small causes can have 

massive effects, as we are currently 

experiencing with the coronavirus 

pandemic. A virus turns the whole 

world upside down in a matter of 

weeks. The consequences of decisions 

are frequently irreversible. A power 

plant which has been shut down, 

deconstructed, and decommissioned 

is lost forever. It is very expensive to 

maintain and reactivate power plants 

which have been mothballed. 

Non-linearity means that many of 

our previous methods of risk assessment 

fail. The delayed consequences 

are particularly deceptive since people 

like to ignore them. They include, for 

example, the 50.2 hertz problem, 

which arises when a large number of 

old installations with inverters disconnect 

from the electricity grid at the 

same time, leading to a yo-yo effect. 

This problem is supposed to have been 

solved, but we do not know whether 

this is actually the case. What we do 

know is that it was ignored for far too 

long. Neither is the effect immediately 

noticeable with the instantaneous 

reserve, or when power plants are 

being shutdown. Things mount up 

and there comes a point when something 

happens which is the last straw 

and can no longer be controlled – 

small cause, great effect. And there 

are no easy cause-and-effect relationships 

which can clearly be made to 

take the blame. Things have simply 

built up over a lengthy period of time. 

The collapse of complex systems is, as 

has been well investigated, not a fault 

but a system design characteristic to 

facilitate a renewal. Economic theory 

uses the term “creative destruction”. 

The new can often develop only when 

the old is broken or has been 

destroyed. If adopted with our most 

important lifeline, our electricity 

supply, it would equate to an intention 

to commit suicide. 

meanwhile between 40 and 50 years 

old. Some are even older. This means 

that far-reaching changes will have to 

be introduced in the next few years. 

But the currently purely economic 

considerations and the uncertain 

framework conditions mean this is not 

worthwhile. Postponing investments 

is thus a popular move, but one which 

increases the susceptibility to failure. 

And when investments are made only 

when it is worthwhile, it is already too 

late. This explains why the liberalized 

electricity market is also contributing 

to reducing the reserves and redundancies. 

What may be acceptable in 

other types of infrastructure could 

come to a nasty end if used for the 

vital electricity infrastructure, as is 

illustrated by the turkey illusion: A 

turkey which is fed every day by its 

owner assumes on the basis of its daily 

positive experience (being fed and 

looked after) that the owner only has 

its best interests at heart. It lacks the 

most important information that this 

care serves only one purpose: On the 

day before Thanksgiving, traditionally 

the day on which the turkeys are 

slaughtered, it gets a fatal surprise. 

This metaphor comes into its own 

with very rare events which have 

enormous consequences, so-called 

extreme events (“X-Events”) or strategic 

shocks. In such cases, we like to 

mistake the absence of proof for the 

proof of absence. 

Extreme weather events 

As if this were not enough, we must 

also expect that extreme weather 

events will become more common in 

Europe just as they already are in 

Australia, California or Texas. This 

also means we have to expect serious 

damage to infrastructures and infrastructure 

outages. The droughts of the 

last few years in particular have posed 

an enormous challenge for conventional 

power plants, which have to 

draw their cooling water from lakes 

and rivers. At the same time, falling 

water levels reduce the capacity of 

hydroelectric power plants. In the 

other extreme case, floods or torrential 

rainfall events cause problems 

with electricity generation, as 

happened in June 2020, for example, 

when a torrential rainfall event 

knocked out the biggest Polish coalfired 

power station and other generating 

plants at the same time, leading 

to a critical gap in supply. 

Energy cells are also affected in 

these situations, but the risk of sudden 

and widespread outages could be 

significantly reduced here. Cells do 

not have greater security of supply 

per se. But they do help to reduce 

the potential damage, and this is 

gaining in importance as a result of 

the problems illustrated. Moreover, 

we are still creating many even worse 

dependencies and hence vulnerabilities 

by developing a structure 

which increasingly lacks borders. 

Lack of predetermined 

breaking points 

The lack of clearly defined, predetermined 

breaking points makes it 

much more difficult to re-establish a 

network. And this is precisely the 

aspect that is to be extended even 

more in the next few years. An EU 

directive requires at least 70 percent 

of the capacity of the border interconnectors 

to be open for the crossborder 

electricity trade by 2025. 

Something which can boost competition 

and thus lower prices on the 

daily level leads on the other hand to a 

massive vulner ability of the whole 

system, because it means that less and 

less consideration is given to the 

physical limits. A possible inter ruption 

can spread much faster and much 

further. These directives are thus 

clearly at variance with a robust, 

cellular approach. 

Aging infrastructures 

The transition to renewable energy is 

not the only reason we are facing a 

time of great upheaval. The bulk of 

the infrastructure will reach the 

end of its service life over the next 

few years. Most power plants are 

| Figure 3 

Turkey Illusion. 




Dangerous trade in electricity 

The role played by the electricity trade 

is paid too little attention on the 

general level as well in respect of the 

risks to the European interconnected 

system. In June 2019, German 

electricity traders brought the system 

to the verge of collapse after they 

exploited a loophole in the regulations. 

Despite receiving a formal 

warning and the prospect of high 

penalties which now loom, loopholes 

still seem to exist. In the first quarter 

of 2021, there have already been over 

60 frequency anomalies, which are 

probably caused by economically 

optimized power plant operational 

planning. In the whole of 2020 there 

were around 140 anomalies. The 

problem is: On the hour and regular as 

clockwork, half to two-thirds of the 

reserve which has been held back in 

order to be able to react to unforeseen 

power plant outages is “consumed”. If 

one or more power plant outages do 

actually occur during this time, which 

is more likely with the timetable 

change, this could rapidly lead to a 

further escalation. Although people 

have long been aware of the problem, 

the regulators do not seem to see the 

need to prevent this misuse. This can’t 

go on forever. 

January 8, 2021 

There are also several indications that 

the two factors, the reduced instantaneous 

reserve and the excessive 

electricity trade, could have played a 

significant role in the major disruption 

on January 8, 2021, even if this has so 

far not been mentioned in any publicly 

available investigation reports. 

At 14:04 on January 8, a bus 

coupling was overloaded in the 

Ernestinovo (Croatia) transformer 

substation, which had then correctly 

shutdown for its own protection. This 

led to 13 other units in Southeast 

Europe being overloaded, causing the 

European interconnected system to be 

separated into two parts. The result 

was a massive increase in frequency to 

50.6 hertz in Southeast Europe caused 

by the massive power imbalance, and 

a drop in frequency to 49.74 hertz in 

Northwest Europe. In the Southeast 

there was excess power of 6.3 GW, 

which was simultaneously not available 

in the Northwest. 

The very steep drop or increase in 

frequency indicates that too little 

instantaneous reserve was available, 

which should have cushioned such a 

significant change in power. On the 

other hand, there was an enormous 

electricity transmission of approx. 

| Figure 4 

Phases of a pan-European electricity, infrastructure and supply outage (“blackout”). 

6.3 GW towards Spain and France at 

the same time. There are hence some 

indications that the transregional 

electricity trade could also have 

played a role here, and led to the overload. 

Another interesting point is that 

the bus coupling in the Ernestinovo 

transformer substation had not been 

classed as systemically important up 

to that point, and had therefore not 

been incorporated into the con tinuous 

safety calculations. This begs the 

question of how many such unnoticed 

breaking points could still exist. The 

incident on January 8, 2021 should 

therefore be understood as a warning 

to be taken very seriously, even 

though politicians immediately maintained 

that the electricity supply was 

secure. Thirty-six countries are all 

sitting in the same boat, and if it 

capsizes, they will all go down with it. 

After a blackout 

Austria is probably one of the first 

countries which will be in a position to 

re-establish a working power grid, 

although this could still take about 

one day or longer. It will take at least a 

week before electricity is flowing 

everywhere again on the European 

level. But that is not all. 

In general, the consequences and 

restart times after a widespread and 

sudden outage of the power supply 

are massively underestimated. Many 

preparatory measures deal only with 

the immediate provisions for the 

power outage, which usually leads to 

the procurement or extension of an 

emergency power supply. Albeit it that 

the outage phase is still the most 

manageable one. The considerably 

longer phases (phases 2 and 3) as 

systems are being restarted will have 

much more serious and catastrophic 

consequences in the other infrastructure 

sectors and during the 

resynchronization of the supply 

logistics, and this is something which 

is completely underestimated in 

this dimension because we have no 

experience of it. 

It is primarily the very high security 

of supply in all areas of our life, especially 

in Central Europe, which will 

backfire on us: There is a general lack 

of self-sufficiency measures or fallback 

solutions. Far too many people 

and organizations simply rely blindly 

on the continuous availability. A 

turkey illusion. 

Protracted restart 

It is thus to be expected, for example, 

that after the electricity supply 

resumes, it will be several more days 

before telecommunication services, 

i.e., cell phones, internet, and landlines, 

are back in operation, because 

serious hardware damage and overloads 

must be expected. This takes us 

to week 2 at least if we are lucky, until 

wide-scale production and goods distribution 

can start up again. This does 

not take account of the international 

intermeshing in the supply logistics. 

And neither the people nor companies 

nor countries are prepared for this. 

There is thus the threat of an inconceivable 

catastrophe, which could end 

in the biggest catastrophe after the 

Second World War. 

What can we do? 

In the short term, the only thing that 

will help is to prepare for the event, 

which means (in a general sense as 

well): Prevention and security are 

important, but not enough. There has 

to be both/and thinking here as well: 

We also have to be in a position to deal 

with unexpected events and get a grip 

on them. This applies at all levels. For 

example, preventing cyber attacks is 

enormously important, yet an IT 

recovery plan is indispensable, even if 

you always hope it will never be 

needed. But hope on its own is not 

enough. The same applies in relation 

to blackouts. We are currently undertaking 

the biggest infrastructure 

transformation of all times – as openheart 

surgery and without a safety 

net. It could turn out to be a fatal 

evolutionary mistake. 

The most important step begins 

within your own four walls: Be able to 

be completely self-sufficient for at 

least two weeks, looking after yourself 

and your family from your own 

pro visions and supplies. This means 






2 liters of water per person per day. 

After the outage, you can cook again 

but it is not possible to go shopping. So 

have provisions such as pasta, rice, 

and tinned food for two weeks. The 

same applies to important medi cation, 

and food for small children and pets. 

Torches, a battery-powered radio, 

rubbish bags and other important 

articles that you might need. In other 

words, things you would take with 

you on a 2-week camping holiday. 

Very low level 

of preparedness 

Several investigations have shown 

that around a third of the population 

could be self-sufficient for a maximum 

of four days, and a further third for a 

maximum of seven days. This is the 

beginning of a vicious circle, because 

when people can no longer provide for 

themselves to a sufficient degree, they 

do not come into work to power up the 

systems again. A vicious spiral is set in 

motion. This explains why broadbased 

self-sufficiency in the population 

is an essential prerequisite for 

being able to cope with such a 

scenario. This especially also relates to 

those organizations and companies 

which must be able to maintain an 

emergency service in such an event, 

including the energy business. 

Stand-alone PV systems 

And many PV owners are not aware 

that their PV system will not supply 

any electricity either during the 

outage, because most systems are 

line-commutated. Only stand-alone 

PV systems, i.e., those supplemented 

with system decoupling, hybrid 

inverters, and storage devices, can 

maintain an emergency supply in their 

own four walls even in the event of an 

outage. So power could continue to be 

provided for lighting, heating, and 

the refrigerator/freezer (provisions!). 

This would noticeably lessen the 

impact of the scenario. From society’s 

point of view, it would be even more 

effective and more efficient to construct 

regional energy cells as rapidly 

as possible, thus ensuring that at least 

a basic emergency supply in respect 

of water, wastewater, heat or healthcare 

services could be maintained. 

even during an outage. This will 

not happen, however, because the 

necessary awareness and the 

requisite framework conditions are 

lacking. 

Organizational measures 

The organizational measures which 

are necessary can then build on these 

personal precautionary measures. 

This represents the first step towards 

sensitizing a company’s own staff by 

giving them a nudge to take their own 

precautions. On the other hand, full 

consideration is required as to how 

the necessary communication can be 

safeguarded in the event of a blackout. 

In many cases, only offline plans, 

i.e., prepared arrangements which 

have to be available in the minds of 

the staff, will work. Key staff have to 

know what to do when nobody else 

can be reached, and how the handover 

and supply operates when an 

emergency service has to be maintained. 

Raising the alarm in the usual 

way will generally not be possible 

because most of the telecommunication 

systems will go down within a 

few minutes of the power outage. As 

far as staff availability is concerned, it 

is primarily their personal circumstances, 

such as how far they have to 

travel to their place of work, or other 

obligations such as family members 

who need to be looked after, offices 

they hold in the local crisis management 

group or emergency response 

organizations, which need to be 

considered. Moreover, an assessment 

must be carried out as to how long the 

available resources, for example the 

fuel for emergency generators for 

emergency operation, will last, since 

there is little hope of external supplies 

coming in if appropriate preparatory 

measures are not taken. This continues 

right through to restart plans, 

where consideration must be given as 

to the conditions which must prevail 

before it is even possible for regular 

operation to be resumed again. 

Summary 

The European electricity supply 

system is currently going through a 

time of radical upheaval, where the 

crux is: “Too many cooks spoil the 

broth.” This situation has arisen 

because there is no systemic overall 

coordination and approach. Each 

member country is transitioning to 

renewable energy in different directions, 

and a coordinated approach is 

difficult to discern. Furthermore, 

fundamental physical and technical 

framework conditions are being 

ignored and replaced with wishful 

thinking, and it is foreseeable that this 

can only lead to disaster. After all, the 

electricity supply system obeys only 

the laws of physics. We can still turn 

away from this disastrous route. This 

would require quick and decisive 

action, but there is no evidence of this 

at present. 

Author 


President of the 

Austrian Society for 

Crisis Preparedness 

(GfKV) 

office@saurugg.net 

Herbert Saurugg is an international blackout and crisis 

preparedness expert, President of the Austrian Society 

for Crisis Preparedness (GfKV), author of numerous 

specialized publications and a requested keynote 

speaker and interview partner on the topic of 

“A Europe-wide power, infrastructure and supply 

breakdown (‘blackout’)”. For the past 10 years, he 

has been researching the increasing complexity and 

vulnerability of vital infrastructures and possible 

solutions for making the supply of vital goods more 

robust again. At www.saurugg.net he runs an 

extensive expert blog on these topics. 




A Role for Nuclear 

in the Future Dutch Energy Mix 

Findings of a Study for the Dutch Parliament 

Bojan Tomic and Mario van der Borst 

Introduction The EU is embarking on the European “Green Deal”, with the target to be “climate neutral” by 2050. 

With majority of EU greenhouse gas emissions coming from production and use of energy, all possible energy sources 

warrant a new look. Facing the need for a drastic reduction of CO 2 emissions over the next couple of decades, while 

having limited back up options for VREs a potential role of nuclear energy for the Netherlands in 2050 has been raised 

by the Dutch parliament. Among seven questions raised by the Dutch parliament (motion Yeşilgöz-Zegerius/Mulder 

(2018/2019 35167NR15) of specific interest were prospects and costs of new NPPs including SMRs, comparison with 

other sources of electricity also considering CO 2 costs as well as potential scenarios including nuclear that are possible 

for the Netherlands. Consideration of the security of supply, reliability, and flexibility as well as new development 

including hydrogen cycle were important. To respond to the parliamentary motion, the Ministry of Economic Affairs 

and Climate Policy of the Netherlands launched a “meta- study” to critically assess and compile information from 

numerous reports while placing those in the specific Dutch perspective. Furthermore, the Study was to examine the cost 

of electricity from nuclear power plants and other low-carbon electricity sources specifically for the Netherlands. 

In their reports, most international 

organisations, from IPCC over US EIA, 

OECD NEA, WEC etc. favour deployment 

of nuclear to cope with climate 

change. Moreover, many see little 

chance of full decarbonisation without 

a significant contribution of nuclear. 

This is in particular so for the countries 

like the Netherlands where there are 

no other possibilities (except fossil) to 

complement the VRE (vari able renewable 

energy) sources. This highlights 

the need for a cost com parison that 

would not just be based on the headline 

LCOE (levelized costs of electricity) 

than rather consider all the cost 

drives, from the cost of financing a 

source of electricity over the operating 

costs including the system costs to the 

cost of decommissioning and waste. In 

this, the Study corrected some of 

previous cost comparisons that often 

excluded realistic system costs and/or 

other subsidies available to VREs such 

as grid connection, etc. Furthermore, 

the effects of the “priority access” to 

the grid were investigated. In particular, 

the notion of a “level playing 

field” was investigated, including 

sensitivity studies to account for uncertainties 

in some of the parameters. 

Upon its publication and presentation 

of the result in the Dutch 

Parliament a lively debate commenced, 

in the Chambers (and its committees) 

but also in the media and among the 

public. As expected, some of the 

particular strong reactions came from 

entities and interest groups representing 

the VREs, which claimed that ENCO 

study reached “wrong conclusion”, 

while falling to establish technically 

sound/justified arguments as what was 

wrong in ENCO Study’s conclusion. 

New nuclear power – 

where do we stand 

As of May 2020, 441 nuclear reactors 

are operating in 31 countries, with 

389,994 MWe total installed capacity. 

Further 54 nuclear power reactors are 

under construction, with a total of 

57,444 MWe total net installed capacity. 

Developing nations with increasing 

energy needs and those 

heavily relying on coal (e.g. China and 

India) are leading the way in ad vancing 

nuclear construction, based on own 

and foreign technologies. Per IAEA, 

about 19 countries are starting or 

planning construction, and even countries 

that have never employed nuclear 

as an energy source, are reviewing 

their position (e.g. Australian Parliament’s 

report). The world nuclear fleet 

generated 2,563 terawatt- hours (TWh) 

of electricity in 2018, a 2.4 percent 

increase over the previous year, which 

was essentially due to China’s nuclear 

output increasing by 44 TWh (+19 %), 

but still 4 percent below the historic 

peak of 2006. 

At the end of 2019, nuclear 

electricity constituted about 26 % of 

the EU’s electricity generation. There 

are 126 nuclear power plants. There 

are active constructions of new NPPs 

in 3 EU Member states, and up to 

6 MS are pursuing nuclear new built, 

of which Hungary expected to issue 

a construction licence for a new 

NPP in 2021. Regardless of massive 

investment in the VRE resources all 

across the EU, nuclear energy 

remains by far the largest (26.7 % in 

2019) single source of low-carbon 

energy in the EU, ahead of hydro 

(12.3 %), wind (13.3 %), and solar 

(4.4 %). 

As a possible contributor to the 

carbon-neutral future, small modular 

reactors (SMR) are receiving increased 

attention. This is due to the 

technological capability of nuclear 

to deliver on-demand electricity, 

coupled with a promise for great 

simplification and related cost reduction 

while applying industrial manufacturing 

and construction technologies 

at a factory rather than on site. 

The SMRs are expected to address the 

biggest obstacle for large nuclear 

power plants: long construction 

periods causing high capital costs. 

Active licensing activities with sites 

elected are underway in USA and 

Canada. Several EU countries expressed 

interest and as per news 

bulletins, some including Estonia and 

Poland started the negotiations with 

potential suppliers of SMRs. 

One of the typical complaints 

regarding nuclear power is that it is 

unsafe. To the wider public, when 

considering with wide media coverage 

and public interest related with any 

nuclear accidents, and in particular 

Chernobyl and Fukushima, such a 

perception is understandable. However, 

the fact of the matter is that no 

one died from the radioactivity 

released during Fukushima accident 

(and as per UNSECAR report released 

on 21st March 2021 “Radiation-linked 

increases in cancer rates not expected 

to be seen”). As per multiple 

studies undertaken on the Chernobyl 

accident and its consequences, 

apart from several dozens of first 

re sponders who died shortly after the 

accident, there was a very limited 

number of deaths caused by the radioactive 

release. To put safety in the 



A Role for Nuclear in the Future Dutch Energy Mix ı Bojan Tomic and Mario van der Borst



| Figure 1 

Fatalities per TW of electricity generated for various sources. 

perspective it is useful to assess the 

fatalities per unit of generated energy 

from various sources of electricity. 

The fatalities caused by the nuclear 

industry in Figure 1 reflect the GEN II 

nuclear plants. Integral to the GEN III 

and SMR reactors is the fundamental 

design requirement of a strict limit to 

any radiological release in a case of 

accident. GEN III nuclear plants as 

well as most SMRs are designed to be 

“inherently safe”, meaning minimisation 

of probability of accidents and 

exclusion of off-site consequences 

even in cases where a hypothetical 

accident is to occur. Deployment of 

such reactors would enable the construction 

also in highly populated 

countries, without concerns of the 

population in the vicinity of a plant. 

This applies even more to future GEN 

IV reactors, where innovative and/or 

revolutionary concepts might be 

expected to lead to fully inherently 

safe designs. 

With that consideration, the notion 

of nuclear not being safe does not pass 

the scientific scrutiny. The energy that 

could have been produced in nuclear 

plants in Germany and instead was 

produced by burning coal, lignite and 

gas, affected the population and even 

much more the climate (in 2018 

German CO 2 emission per capita was 

almost double of that in France or the 

UK) not just in Germany but also in 

the neighbouring countries. 

Another criticism of nuclear power 

is that it generates radioactive waste 

that will remain dangerous for 

millions of years to come. While 

notionally true, it is also well known 

and often ignored that the amount 

of waste that remain dangerous for 

extended period of time is extremely 

small. Every other source of energy, 

even VREs generates waste that 

is dangerous to people and the 

environment and would need to be 

safely isolated, in quantities that are 

(much) larger than the radioactive 

waste generated in nuclear plants. 

Important advances have been 

achieved in the management of longlived 

high-level radioactive waste. 

Disposal in special canisters in geologically 

stable layers in the deep underground 

is inter nationally regarded 

as a safe solution. Pragmaticallygoverned 

countries, in particular the 

EU Member states in Scandinavia, 

implemented solutions for long-lived 

waste that guarantees no effect to the 

public and environment for much 

longer periods that the humankind 

exist on the Earth. It is useful to put 

that in the perspective of currently 

non-recyclable PV panels, or ever 

increasing needs for exotic material 

including rare earth, cadmium or 

lithium, mining and processing of 

which leave enormous impact on 

the environment and its residues 

entering the water supply affecting 

the world’s population today. Furthermore, 

unlike any other sources of 

electricity, nuclear has from the very 

beginning been planned to require 

plant operators to make a provision 

for decommissioning and for disposing 

of any waste, thus these costs 

are ‘ internalised’ as part of operating 

costs. No other source of electricity in 

the use today fully operates on such a 

principle. 

Societal costs of nuclear 

Every source of electricity (or indeed 

practically any other human activity) 

has external impact that are not fully 

reflected in the price, but which 

society as a whole must bear. The best 

example is the cost of emissions, 

which may (and in reality already is) 

cause damage to those who are 

not related nor benefitting from the 

activities. In the case of electricity 

generation, the external costs of 

interest are those related with three 

components: emissions of CO 2 and 

resulting climate change; damage/ 

impact such as on health and crops 

associated with air, water or environmental 

pollutants and other nonenvironmental 

social costs. 

External costs to the society from 

the operation of nuclear power could 

assumed to be negligible as there are 

no emissions from the operation, and 

the cost of management of waste 

and decommissioning are internalised, 

meaning included in the price. 

Nevertheless, one might argue that a 

serious accident causing damage 

which is beyond the insurance limit 

might become the societal costs. However, 

for modern nuclear plants the 

probability of such an accident is 

extremely low and societal costs might 

be expected not to exist for the Gen III 

or inherently safe SMRs. 

Electricity generation from fossil 

fuels is not regulated in the same way, 

and therefore the operators of thermal 

power plants do not to internalise the 

costs of greenhouse gas emission or of 

releases in the atmosphere. In some 

countries this is being addressed 

through the CO 2 pricing. For VREs the 

impact of the decommissioning and 

waste management are not even 

known, effectively making the future 

societal cost. 

Externalities of electricity production 

are not limited to environmental 

and health related impact, but may be 

related with macro-economic, policy 

or strategic factors not reflected in 

market prices, such as security of 

supply, cost stability and broad economic 

impacts including employment. 

Although those externalities generally 

have not been subjected to systematic 

assessment and comparison, some 

qualitative analysis established high 

advantage for nuclear as compared 

with any other sources of electricity 

on the majority of the parameters of 

interest. 

One further aspect for consideration 

is in relation to the social impact 

is the land utilisation. For this aspect, 

the extremely high energy density of 

nuclear (up to about a 1000 times) is a 

great benefit compared to VREs. Due 

to its low energy density, VREs require 

lots of space. This is particularly 

relevant for solar PVs, where the 

installations are competing with land 

available for agriculture and/or 

encroaching the preserved nature, 

and for onshore wind, where increased 

opposition due to noise (on 




| Figure 2 

The cost breakdown for Hinkley point C NPP. 

shorter distance), drop shadow and 

intrusions into natural settings is 

becoming omnipresent. 

Especially in densely populated 

parts of Europe, such as the Netherlands, 

enormous needs for space for 

some of the technologies is becoming 

increasingly a limiting factor in the 

deployment. Further to this, the 

disturbance of the landscape complains 

are on the raise everywhere. 

Although the “NIMBY” phenomena 

affects any intervention, a much 

higher energy density of nuclear 

plants, the number of people affected 

is only a fraction of those affected by 

the low energy density VREs. 

The cost of nuclear power 

Often raised drawback for nuclear 

power is that it is just “too expensive”. 

Clearly, judging from the headline 

numbers, e.g. the price of two large 

GEN III nuclear units under construction 

at Hinkley point in the UK is 

above 24 billion Euros, or multiple 

costs increases for similar units in 

France (Flamanville 3) or Finland 

(Olkilouto 3), the cost are very high. 

Furthermore, many were astonished 

with so called” strike price” for the 

electricity from Hinkley point C being 

94 GBP per MWhr when comparing 

that with currently traded price of 

about 50 to 60 GBP MWhr. However, 

the comparison with the strike price of 

about 140 GBP per MWhr for nondispatchable 

offshore wind sources provides 

a bit of perspective. To assess the 

cost of nuclear it is important to understand 

its background. The cost comparison 

with other sources using the 

“levelized cost of electricity” (LCOE) 

provide interesting insights. 

The construction of a nuclear plant 

is a large and extremely complex 

undertaking. While at the time of the 

most intensive deployment of nuclear 

plants in late seventies and eighties of 

the last century, typical construction 

period was in the order of 5 or so years. 

| Figure 3 

Cost of nuclear electricity in relation with WACC. 

With fewer nuclear plants being 

built nowadays, the construction duration 

extended dramatically, beyond 

15 years and counting for the EPR 

reactors in Finland and France. Given 

the high costs of a plant itself, just the 

cost of deployed capital over such a 

long period significantly contributes to 

the overall cost. How ever, this is not 

unique to nuclear plants. Other large 

and complex infrastructure projects 

experienced similar extension of the 

construction periods and resulting 

effects on the costs, e.g. an airport 

(BER, a factor of 3 cost increase) or a 

railway (Crossrail, factor of 3.5 cost 

increase and counting). The difference 

to those is in the financing costs. 

The cost of capital 

Where the nuclear plants are really 

penalised, and which is the dominant 

cause of their high price, is the costs 

of the capital. While infrastructure 

projects such as BER and Crossrail 

attract the capital with very low costs, 

due to a perceived risk related to 

nuclear projects, the cost of capital 

encompasses a risk premium. In 

the costs profile of new nuclear the 

majority is indeed the costs of capital, 

i.e. interest and risk premium. For 

Hinkley point C, about 65 % of the 

total cost of the plant is associated 

with interest payment. 

It is obvious that with the cost of 

capital as it is in the EU today (zero or 

negative interest rates), an investment 

model where two thirds of the cost is 

to cover the interest is not sustainable. 

With the weighted cost of the capital 

(WACC) in the range of 4 %, simular 

to what is used in VRE projects, 

nuclear becomes fully cost com petitive 

with other sources of carbon free 

electricity. 

The system cost 

Apart from the costs of investment 

(construction) and operating costs 

(fuel, operation, maintenance) various 

| Figure 4 

The contributors to cost of electricity, comparison between 

nuclear, solar and wind. 

energy technologies would have 

specific costs related to the integration 

into the electricity supply system. The 

system costs typically include the 

balancing costs (deviations from the 

planned production and extra cost for 

investment in reserves), the profile 

cost (technology dependant, i.e. 

anti- cyclicals able to achieve higher 

prices) and the grid cost (extra cost of 






expanding the grid). The system costs 

are highly dependent on the configuration 

of the electrical system – the 

energy mix. The system costs is 

what differentiate between reliably 

dispatchable energy sources being 

able to supply agreed electricity to the 

grid and non-dispatchable ones, being 

dependant on external influences like 

weather and therefore requiring 

backups. For the VREs, the system 

costs are also dramatically increasing 

with the penetration, while dispatchable 

technologies might be credited 

with system benefits due to being able 

to vary their outputs to support system 

stability. 

The further point of attention is the 

electric potential (in installed MW) 

that is needed to guarantee the supply 

of electricity in dispatched MWh. This 

is best explained by comparing solar 

and nuclear. Because of the capacity 

factor of about 10 % for solar and 

90 % for nuclear, the installed capacity 

for solar to generate the same 

amount of electricity needs to be 

9 times larger. The LCOE cost calculation 

takes this into the account only as 

far as the expected production of 

electricity from different sources is 

concerned (i.e. capacity factor). However, 

the grid costs and in particular 

the balancing and profile costs to 

assure reliable supply of electricity, 

are (much) higher for VRE, and 

dramatically increasing with the 

higher penetration. The system costs 

strongly depends on the geography 

i.e. whether large hydro is available. 

Typical studies addressing the system 

costs always take into the account a 

certain proportion of hydraulic plants, 

which is not the case in countries such 

as the Netherlands. 

Another important consideration is 

that the deployment of a large share of 

variable-electricity generating sources 

with (nearly) zero marginal cost has a 

profound impact on the functioning of 

electricity markets and on the operation 

of the generating capacity. In the 

short term, reduced load factors (the 

compression effect) and lower prices 

| Figure 5 

The relation of system cost to the penetration of VREs. 

affect the economics of all dispatchable 

generators. Above certain level of 

penetration of VRE and at specific 

weather conditions, there would be 

no other generators on the market, 

leading to a necessity of shutting 

down some of the VRE producers. At 

that time the implicit promise (i.e. the 

state guarantee) that all electricity 

that would be generated by VREs will 

be taken by the grid and delivered to 

the consumers suddenly disappears, 

further increasing system cost but 

also the LCOE due to lower overall 

utilisation. 

The system costs for the dispatchable 

sources such as nuclear or coal/ 

gas are very small, in the order of 

2 Euro/MWh. With a low penetration 

of VRE, the system costs remain small, 

as there are enough reserves to 

balance the grid when VREs are not 

generating. With an increased penetration 

of VRE, and in particular above 

about 50 %, the system costs become a 

dominant contributor, as documented 

in the research of the IEA in the 

Figure 5. 

The decarbonation of electricity 

supply with VRE only leads to the 

situation of both very high costs (due 

to electric potential, needs for grid 

development, etc.) AND accepting 

regular blackouts as there will be 

periods when none of the VREs would 

generate electricity. Availability of 

VREs is internally closely related, i.e. 

non redundant: doubling the amount 

of PV panels will not add to overnight 

supply; all windmills would stand still 

when there is no wind. 

The studies analysing VRE role in 

the electric supply often significantly 

underestimate system cost by projecting 

upwards from the current situation 

where there is 10-20 % penetration. 

Sometimes the “low” system 

costs are justified with the assumption 

that electricity will be unavailable for 

certain amount of time, which is very 

likely not acceptable to today’s society. 

Furthermore, typically advertised 

“low cost of VRE” often exclude the 

grid connection cost, which in a case 

of offshore wind becoming a dominant 

contributor. On the contrary, 

nuclear is constantly dispatchable, 

able to balance the grid and its investment 

costs already include the grid 

connection. 

It should be highlighted that some 

nuclear plants are now being approved 

to operate for 80 years, while the wind 

generators and solar panels have projected 

lifetime up to a maximum of 

25 years (with discernible degradation 

over the lifetime for solar PV). 

Typically, after about 25 years, the 

investment in a nuclear plant is 

already paid off. For VRE, this is 

exactly the time when the new investment 

cycle is needed. 

The LCOE estimates for the 

Netherlands for the year 2040 

The key request by the Ministry of 

Economic Affairs and Climate Policy 

was to estimate the LCOE for several 

electricity generation technologies 

for the year 2040, on a comparable 

basis specifically for the Netherlands. 

The study considered the following 

emission free sources of electricity: 

p Large nuclear GEN-III plant 

p Nuclear SMR 

p Off-shore wind 

p On-shore wind 

p Large solar PV 

p Hydrogen Power 

To make this comparison meaningful 

with expected higher (50 %) penetration 

of VREs, the adjusted “LCOE*” 

was calculated to include the system 

effects, as defined by the OECD NEA. 

A full utilisation was assumed for 

all sources of electricity, meaning that 

each source would be allowed to 

deliver to the grid when it is capable to 

deliver, independent of electricityexchange-market 

or other prioritization 

mechanisms. For the stability of 

the electrical grid with the higher VRE 

penetration rates, VRE units would 

also be obliged to shut down or reduce 

the output at certain moments, like 

now is the case with the dispatchable 

plants. This will result in the utilisation 

rates being lower than 100 %. As 

those are not driven only by economic 

considerations, rather by political and 

other issues, the Study did not elaborate 

further on the expected utilisation 

rate. The basis assumption for the 

assessment is included in the list in 

the following table. 

The findings could be best illustrated 

by the summary Figure 6. 

The results are pretty obvious: 

even limiting the VRE penetration rate 

to 50 %, the system costs became so 

dominant that the dispatchable sources 

are visibly cheaper than the VREs. 

Compared with the offshore wind, 

onshore wind and solar PV, two 

nuclear options remain cheaper when 

realistic system costs are considered in 

the LCOE*. The Hydrogen Round trip 

is very costly. The expla nation is in the 

low efficiency, between 25 % and 

39 % for the electrolyser and the 

turbine, meaning that 60 % to 75 % of 

the energy is lost in the process. The 

hydrogen storage is assumed to 

be in the salt-caverns. When storage 




in high pressure casks is selected, the 

LCOE* for this option could be 5-10 

times higher. 

As with any prediction for the 

future in a dynamic and changing 

environment, the point values might 

be far off if the assumptions change. 

All such estimations, and in particular 

those that are addressing the more 

distant future, could only be made on 

the basis of a set of assumptions, covering 

wide range of issues, from the 

technology development to the cost of 

financing and learning curves. While 

the projections of the LCOE* are considered 

the best estimate, it was highly 

interesting to assess how those estimates 

would be influenced by changes 

in the assumptions and/or relevant 

parameters. The Study undertook a 

series of sensitivity analysis, covering 

the following: 

p Construction times (duration) 

p Learning effects consideration 

p Impact of the lifetime of a plant 

p Utilisation rates of a plant 

p Interest-rate (WACC) sensitivity 

p System costs sensitivity 

p Sensitivity cases for hydrogen 

utilisation 

The results are depicted in the 

Figure 7, indicating the effects of 

uncertainties. 

The example sensitivity case for 

the VRE penetration rate of 75 % 

shows an interesting correlation. The 

increased penetration of VREs from 

about 50 % to about 75 % leads to 

approximately doubling of the system 

costs for every technology. However, 

for the technologies with lower system 

costs, this effect is barely visible while 

for the non-dispatchable sources of 

electricity it dominates, as in the 

Figure 8. 

ENCO report caused quite a 

stir in the Dutch media and 

politics 

The prevailing public opinion in the 

Netherlands is that nuclear indeed 

contributes to lowering the emissions, 

but that the costs would be many 

times higher than solar and wind 

energy. Reference is often made to the 

cost overruns of the new construction 

projects in Finland and France. As a 

result, enthusiasm for nuclear energy 

decreased even among the most 

interested parties. 

The ENCO report made it clear that 

nuclear energy can compete with 

solar and wind energy in the future, if 

the system costs are allocated to the 

energy source causing those. This 

message did not please the renewable 

energy interests and many articles 

General assumptions 

LCOE assessment Nuclear VRE 

WACC 7 % 4,3 % 4,3 % 

| Table 1 

The relation of system cost to the penetration of VREs. 

appeared in the media contradicting 

the Study conclusions. Most of the 

articles lacked factual arguments and 

attempts were made to discredit the 

authors of the ENCO report. 

The consultancy firm Kalavasta, 

which had previously published a 

report on the “Costs of Nuclear 

Energy”, wrote a negative assessment 

report, mainly focusing on the fact 

that” system costs are not that high”. 

The conclusion and arguments used 

have been thoroughly refuted by the 

Dutch journal Kernvisie. 

Reflecting Kalvasta criticism of the 

ENCO report, questions were asked in 

the Dutch parliament. The Parliamentary 

committee organised a round 

table discussion on December 2 nd 

2020 attended by the members of 

the Parliament and a variety of 

experts from energy companies, 

NGOs, consultancies and universities. 

Unsurprisingly, this discussion ended 

in a draw. 

In the meantime, EPZ, the operator 

of the nuclear power plant Borssele, 

announced that it is preparing the 

extension of its lifetime after 2033 

and consideration for the expansion 

of Borssele site with two new large 

nuclear power plants. Several Dutch 

provinces, such as Zeeland and 

Brabant, do not rule out nuclear 

energy as a solution for achieving a 

100 % CO 2 neutral economy by 2050. 

On March 17 th the elections for the 

Dutch parliament took place. Nuclear 

energy was one of the major discussion 

topics during the campaign, 

including the argument that there is 

not sufficient space in the Netherlands 

to rely on wind and solar energy 

for decarbonisation. The opponents 

claiming that nuclear energy is too 

expensive. The political parties that 

believe in a role for nuclear energy to 

tackle the climate problem represent 

the majority in the new Dutch 

| Figure 6 

LCOE* for the decarbonised generation for the Netherlands in 2040. 

| Figure 7 

The results of sensitivity analysis on the LCOE*. 

Hydrogen 

P2P 

Technical Lifetime (years) 60 25 20, electrolysers limiting 

Depreciation period technical lifetime technical lifetime technical lifetime 

Utilisation factor 100 % 100 % 50 % 

Decommissioning costs 

Waste costs 

15 % of capital costs, 

discounted at 3 % 

Spent fuel dis posal and 

storage, decomm. waste 

included in decomm. costs 

and operational waste in 

O&M costs 

5% of capital costs, 


Decommissioning waste 

included in decomm. 

costs and operational 

waste in O&M costs 

5% of capital costs, 


Decommissioning. waste 

included in decomm. 

costs and operational 

waste in O&M costs 

Construction time (years) 7 0,5 – 1,5 3, CCGT limiting 

| Figure 8 

The results of sensitivity analysis on the LCOE*. 






parliament (80 out of 150 seats). It is 

expected that the nuclear option will 

be the topic for the Dutch political 

discussions for the coming years. 

From financial standpoint it is 

recognized that system costs are 

the discriminating factor between 

nuclear and the VRE. Numerous 

institutes, including PBL, TNO but 

also Berenschot/Kalavasta, involved 

in the development of the Dutch 

energy scenario studies all consider 

system costs in their analysis. However, 

the system costs as projected for 

VRE are (by far) too optimistic and 

systema tically fail to consider obvious 

uncertainties. The extrapolation from 

the present situation to the one where 

VREs predominate is obviously impossible, 

because in the present world 

the VRE caused system costs are 

absorbed by the still-available margins 

in the electrical system. Some studies 

consider arrangements to moderate 

system cost including smart grids, 

load rejection, car-loading systems 

and decentralised generation enable 

short transport trajectories. All these 

solutions have their limitations and 

many are not established and their 

technical merits and general acceptance 

is uncertain. Furthermore, zero 

curtailment (100 % utilisation) is 

assumed for the VRE, and 50 % to 

70 % curtailment for nuclear. With 

higher VRE penetration this becomes 

impossible and furthermore it obviously 

does not establish a level playing 

field, where all CO 2 free generators 

should have the same priority to the 

grid. 

Conclusions 

The outcome of the Study for the 

Netherlands lead to some interesting 

insights. When the system costs are 

properly accounted for, two nuclear 

options are markedly cheaper than 

the offshore wind and significantly 

cheaper than photovoltaic. This is 

even before other (positive) externalities 

are considered, e.g. the lifetime 

of nuclear plants being 60 or 

even 80 years, while the VREs at best 

last for 25 years, the spatial impact of 

nuclear is a minuscule fraction of that 

for the VREs, or that the cost of 

nuclear already include provisions for 

decommissioning and safe disposals 

of all of its waste. 

The positive vision on future 

developments is affecting all technologies, 

though mainly the offshore 

wind and nuclear SMR. For large 

nuclear significant saving could be 

achieved by reducing the duration 

of the construction; it is however 

uncertain whether nuclear industry 

would be able to erect a NPP in Europe 

in less than 7 years. A much more 

dramatic impact is observed with the 

reduction of the capital costs for a 

nuclear plant. When the WACC is 

reduced from 7 % to 4,3 %, the 

resulting decrease of LCOE* is around 

25 %. With some EU governments 

being able to borrow at negative rates, 

low WACC for nuclear by implementing 

risk- sharing instruments becomes 

a pretty logical con sideration. 

When the design lifetime of nuclear 

plant is being extended from 60 to 

80 years, the impact of this change on 

LCOE* appears low. This is because of 

the devaluation of money, the impact 

of the last 20 years on the LCOE* in 

relation to the full lifetime is not that 

significant (due to the constant value 

calculation). 

The LCOE* of all electricity generation 

sources is driven by capital costs. 

All sources have roughly the same 

dependence on the utilisation, as all 

need to operate to generate income. 

The impact from 100 % to 60 % is 

moderate. Below 60 %, the LCOE* 

increases fast. 

The LCOE* of Hydrogen Round 

trip units is extremely high, especially 

affected by lower utilisation factor of 

electrolysers. At the UF of 20 %, a 

typical utilisation factor of a “Peaker” 

unit, the LCOE* will increase to above 

700 €/MWh. 

Nuclear power emits no greenhouse 

gases. The complete nuclear 

power supply chain, from uranium 

mining to waste disposal, including 

the construction and operation, is 

estimated to emit only 2–6 grams of 

CO 2 per kilowatt-hour generated. This 

is less than even wind and solar, and 

up to two orders of magnitude fossil 

fuels. Nuclear should not be viewed as 

being in competition with “renewable” 

sources of energy, such as wind or 

solar. As the reduction of carbon emissions 

becoming a top priority, both 

nuclear and renewable sources have 

both roles to play. 

Possibly the most relevant finding 

from the Study is that with the 

level playing field for all non-carbon 

emitting sources for electricity, 

nuclear is fully competitive and even 

dominates other sources in several 

areas. The current situation where 

VREs are effectively subsidized by 

having guaranteed income (i.e. all 

VRE generation is taken by the grid 

and paid for at a predetermined price, 

regardless of the need for such 

electricity) will became impossible 

with higher penetration of VREs, as 

some will have to periodically shut 

down. This, together with system 

costs, further undermines the competitiveness 

of VREs. On the contrary, 

nuclear with its guaranteed dispatchability 

and reliability of supply, when 

financed with capital costs that are 

prevailing in the markets today, 

becomes the most affordable non 

carbon emitting source of electricity. 

Authors 

Bojan Tomic 

Principal Consultant 

ENCO, Vienna, Austria 

b.tomic@enco.eu 

Bojan Tomic has more than 35 years experience in the 

nuclear sector internationally. He started his career as 

the designer of nuclear plant safety systems at 

Combustion engineering in USA. He was a First officer 

at the IAEA’s Nuclear safety division, with responsibilities 

for probabilistic safety assessments and operational 

safety. He continued his career as a consultant 

with ENCO, advising clients on various aspects of 

utilisation of nuclear and radiological technologies 

worldwide. He was engaged in numerous modelling 

and analytical studies, including due diligence 

assessment for new nuclear units. Bojan has been 

involved with many nuclear safety initiatives at the EU 

level, most notably in the EU Post Fukushima Stress 

test activities, where he led the peer review team 

assessing national stress tests in several countries 

including Germany. More recently he was on the 

Board of ENSREG’s Topical peer review on Ageing 

management of NPPs. Mr Tomic is a member of the 

Borssele Benchmark committee. 

Mario van der Borst 

Principal Consultant 

2mario@zeelandnet.nl 

Mario van der Borst started his career in R&D at TNO 

in the Netherlands. In 1984 he entered the Nuclear 

Industry. He specialized in Thermo-Hydraulics and 

Probabilistic Safety Assessments. He was responsible 

for major back-fitting and O&M projects at the NPP 

Borssele. From 2003 till 2010 he was the Technical 

Director of this plant. In 2010 he entered the RWE 

New Build Team to be responsible for Technology, 

Authorization and Regulation. At that time RWE was 

involved in NNB projects in the UK, Netherlands, 

Romania and Bulgaria. He is president of the Dutch 

Nuclear society. At the moment he is principal 

consultant. 




BREST-OD-300 – Demonstration 

of Natural Safety Technologies 


Introduction The article discusses the need to update the strategy for the development of nuclear power, various 

approaches to the development of large-scale nuclear power. The current state of fast reactor technologies development 

is examined through the example of the BREST-OD-300 reactor plant and the closed nuclear fuel cycle (CNFC) in Russia 

with highlighting the main problems. The problems of choosing solutions for fast reactors and organization of the 

nuclear fuel cycle are discussed within the article as well. 

Evaluation of prospects for the 

development of the nuclear power 

industry in Russia and other countries 

shows the presence of two trends [1]: 

1. Focusing on the development of 

the nuclear power industry on the 

basis of the existing and improved 

types of thermal reactors with an 

open nuclear fuel cycle that use 

mainly U-235. This also includes 

possibilities of using a limited additional 

fuel resource in the form of 

mixed oxide uranium-plutonium 

fuel (MOX-fuel). It is obtained by 

single recycling of spent nuclear 

fuel (SNF) from these reactors, 

separation of accumu lated plutonium, 

and mixing it with depleted 

uranium. Despite a long history, 

the share of MOX fuel in the world’s 

nuclear fuel pro duction for thermal 

reactors has never exceeded 

5 %, and its production at some 

plants ( Belgium, UK) is ceasing. 

2. Focusing on the development of the 

closed nuclear fuel cycle (NFC) 

with the introduction of reactors 

ensuring simple nuclear fuel conversion 

or nuclear fuel breeding 

(BR ≥ 1). These could be conventional 

fast neutron reactors (FNRs) 

or the light water hard spectrum 

reactors (LWRs) previously discussed 

in the 1970s and newly 

proposed in the United States and 

Russia. Nuclear fuel breeding 

provides full-scale involvement of 

natural uranium (with 99.3 % 

U-238) in the plutonium- uranium 

breeder producing fissionable 

plutonium from U-238 and fissionable 

U-233 from natural Th-232 in 

the breeder reactor. 

The first approach involves evergrowing 

quantities of natural uranium 

that is used less than 1 % energy-wise, 

and the amount of accumulated SNF 

constantly in creases. In the conditions 

of modern energy markets, this 

approach is recognized as economically 

justified. A concept of 

further development of this approach 

has spread in the Unites States, which 

has the largest nuclear power industry 

in the world, and has been promoted 

by leading nuclear power plant (NPP) 

designers in emerging countries, 

where nuclear power engineering is in 

progress. According to American 

experts, the world‘s known uranium 

resources make it possible to stay on 

this track for a long time. 

It is obvious that large-scale nuclear 

power engineering can be implemented 

only under the second 

approach. But development strategies 

under this approach are conceptually 

different in different countries, 

depending on the expected role of 

fast-neutron reactor (FNR) in the 

structure of the nuclear power industry. 

There are three strategies for the 

formation of large-scale nuclear power 

engineering, which can be conditionally 

distinguished: [1]. 

“AS USUAL” Strategy. The United 

States in the foreseeable future will 

rely on thermal light water reactors 

(LWRs) with the open NFC, and 

provision is made for the transition to 

SNF reprocessing from LWR (being 

accumulated in a tem porary storage 

facility for 100 years) in order to 

reduce the amount of high level waste 

(HLW) subject to final disposal by 

means of burning of minor actinides 

(MA) from HLW in an FNR. At the 

same time, FNRs themselves are 

considered as noncompetitive energy 

generators and possible “cleaners” for 

the dominant LWRs. For such FNRs, a 

breeding ratio (BR < 1) is adopted, 

and their NFCs remain open, since it 

requires a constant external (not from 

the NFC) makeup by fissile nuclides. A 

possibility of using FNRs with BR ~ 1 

and BR > 1 is under consideration, 

but their mission remains fundamentally 

the same. 

Closed NFC with thermal reactors 

(TRs). France and Japan, which 

do not have their own uranium deposits, 

have traditionally built their development 

strategies providing for the 

transition from LWRs with the open 

NFC to sodium-cooled FNRs with the 

closed NFC and a BR much larger 

than 1, ensuring LWR makeup fuel 

supply. A similar strategy was considered 

and has still been proposed bv a 

team of specialists in Russia. 

Closed NFC with FNR. The 

Russian Strategy Guidelines formulated 

in the “Strategy for the Development 

of Russia’s Nuclear Power Industry 

in the First Half of the 21 st Century” 

[2] and worked out in detail in [3] is 

based on the concept of large-scale 

nuclear power engineering, which can 

be used to solve its main tasks by 

means of FNRs of moderate power 

rate without surplus plutonium produc 

tion remaining in the structure of 

previously built NPPs with thermal 

reactors. In this case, the complete 

inner plutonium breeding (IBR » 1) 

with dense nitride fuel of equilibrium 

composition is important. 

Scenarios for the formation of 

FNRs with the closed NFC should be 

based on the actually established 

structure of the nuclear power industry. 

In this regard, it is important to 

understand the difference between 

temporary two-component nuclear 

power engineering ensuring a gradual 

transition from thermal reactors to 

FNRs, and basic two-component 

nuclear power engineering, where 

thermal reactors play a key role and 

fast breeder reactors only feed them 

with fuel and burn HLW. 

The idea of the basic twocomponent 

nuclear energetics was 

developed in the second half of the 

last century under the influence of the 

following factors: 

p Development of uranium enriched 

thermal reactors for military 

purposes and their further modernization 

for the civilian power 

engineering; 

p Understanding of the necessity of 

FNRs for the development of 

nuclear power industry; 

p Economic uncompetitiveness of 

fast reactors reactors built in 

dif ferent countries with their 

specific features determined by the 

41 

OPERATION AND NEW BUILD 


BREST-OD-300 – Demonstration of Natural Safety Technologies ı Vadim Lemehov and Valeriy Rachkov


OPERATION AND NEW BUILD 42 

Imprint 

Official Journal of Kerntechnische Gesellschaft e. V. (KTG) 

Publisher 

INFORUM Verlags- und Verwaltungsgesellschaft mbH 

Robert-Koch-Platz 4, 10115 Berlin, Germany 

Phone: +49 30 498555-33 

www.nucmag.com 

@atw_Journal 

@atw-international-journal-for-nuclear-power 

General Manager 

Dr. Thomas Behringer 

Editor in Chief 

Christopher Weßelmann 

+49 2324 4397723 

christopher.wesselmann 

@nucmag.com 

Advertising and Subscription 

info@nucmag.com 

Editorial Advisory Board 

Frank Apel 

Erik Baumann 

Dr. Erwin Fischer 

Carsten George 

Eckehard Göring 

Dr. Florian Gremme 

Dr. Ralf Güldner 

Carsten Haferkamp 

Dr. Anton Kastenmüller 

Prof. Dr. Marco K. Koch 

Herbert Lenz 

Jan-Christan Lewitz 

Andreas Loeb 

Dr. Thomas Mull 

Dr. Joachim Ohnemus 

Olaf Oldiges 

Dr. Tatiana Salnikova 

Dr. Andreas Schaffrath 

Dr. Jens Schröder 

Norbert Schröder 

Prof. Dr. Jörg Starflinger 

Dr. Brigitte Trolldenier 

Dr. Walter Tromm 

Dr. Hans-Georg Willschütz 

Dr. Hannes Wimmer 

Layout 

zi.zero Kommunikation 

Antje Zimmermann 

Berlin, Germany 

Printing 

Editor 

inpuncto:asmuth 

druck + medien gmbh 

Buschstraße 81, 53113 Bonn, Germany 

Nicole Koch 

+49 163 7772797 

nicole.koch 

@nucmag.com 

Managing Editor 


+49 30 498555-21 

nicolas.wendler 

@nucmag.com 

Price List for Advertisement 

Valid as of 1 January 2021 

Published bimonthly, 6 issues per year 

Germany: 

Per issue/copy (incl. VAT, excl. postage) 32.50 € 

Annual subscription (incl. VAT and postage) 183.50 € 

All EU member states without VAT number: 

Per issue/copy (incl. VAT, excl. postage) 32.50 € 

Annual subscription (incl. VAT, excl. postage)183.50 € 

EU member states with VAT number 

and all other countries: 

Per issues/copy (no VAT, excl. postage) 30,37 € 

Annual subscription (no VAT, excl. postage) 171.50 € 

Copyright 

The journal and all papers and photos contained in it 

are protected by copyright. Any use made thereof 

outside the Copyright Act without the consent of the 

publisher, INFORUM Verlags- und Verwaltungsgesellschaft 

mbH, is prohibited. This applies to repro ductions, 

translations, micro filming and the input and 

incorpo ration into electronic systems. The individual 

author is held responsible for the contents of the 

respective paper. Please address letters and manuscripts 

only to the Editorial Staff and not to individual 

persons of the association's staff. We do not assume 

any responsibility for unrequested contributions. 

Signed articles do not necessarily represent the views 

of the editorial. 

ISSN 1431-5254 

require ments of a large BR: high power density, use of a 

sodium coolant, pro duction of weapon-grade plutonium 

in the blanket. 

With the development of the uranium enrichment technology, 

thermal reactors became the basis of modern 

nuclear power engineering, and, for more expensive FNRs 

with a large BR, they could be used for thermal reactors’ 

makeup fuel supply (with plutonium produced by FNRs) 

in case of cheap natural uranium depletion. In such a 

two-component nuclear power industry, a large-scale SNF 

and MOX fuel circulation is required between fast and 

thermal reactors and centralized nuclear fuel recycling 

plants. 

The “Strategy for the Development of Russia’s Nuclear 

Power Industry in the First Half of the 21 st Century” [1] 

considers two-component nuclear power as a Stage of a 

gradual tran sition from thermal to fast neutron reactors, 

which forms the basis of the future large-scale power 

industry. 

The main large-scale development factors of the nuclear 

power industry in Russia and the world remain safety and 

economic competitiveness with other types of energy 

generation. Russia’s nuclear power processing datum 

surface on the basis water-water energetic reactors (VVER) 

reactors is sufficient for the scale of NPP construction and 

volume of exports forecasted by the ES-2030. [4] However, 

its long- term strategic potential is limited by the inconsistency 

of a safety level with requirements for large-scale 

nuclear power engineering, limited natural uranium 

resources, SNF accumulation, and falling competitiveness 

due to increased safety measures. 

The “Strategy for the Development of Russia’s Nuclear 

Power Industry in the First Half of the 21 st Century” [2] 

defined main conditions for natural safety of a large-scale 

nuclear power industry: 

p Elimination of accidents requiring evacuation, and 

especially resettlement of the population and withdrawal 

of significant areas from economic use; 

p Effective use of energy potential of the extracted fuel 

raw materials; 

p Circulation of nuclear materials in the fuel cycle 

without significant violation of the natural radiation 

balance 1 ; 

p Technological support of the nonproliferation of 

nuclear weapons; 

p Ensuring the competitiveness of nuclear power 

engineering in comparison with other types of energy 

generation. 

The abandonment of the thermal reactor plutonium 

makeup from the SNF solves the problem of choosing 

between a large or small FNR BR in favor of the inner BR 

(IBR) close to l. It should be noted again that the smallscale 

nuclear energy system (NES) component is an 

imperative associated with acceptable safety of the largescale 

nuclear power engineer ing, while the choice between 

the hybrid NFC (with the enriched uranium makeup) and 

a closed NFC (with the plutonium makeup from the FNR 

SNF) is a matter of economic feasibility. 

Sometimes fears are expressed that in the case of a FNR 

BR close to one, it is impossible to increase the power of the 

nuclear power plant in a short time (if necessary). But, 

firstly, today even the most optimistic forecasts do not 

1 Preservation of the natural radiation balance assumes that, after a certain 

historically short period of time, the total radioactivity and radiotoxicity of the 

waste generated as a result of the NPP operation, reprocessing of irradiated fuel 

and land-buried waste will not exceed the total radioactivity and radiotoxicity of 

the uranium isotopes extracted from the earth’s crust to supply NPPs with fuel. 




discern such a scenario for 

the development of nuclear power. 

Secondly, if such a scenario turns out 

to be in demand, then, without going 

beyond the natural safety, it can be 

implemented by quickly putting in any 

rationally required amount of FNR 

capacity with fuel from enriched 

uranium or using a blanket, the 

presence of which in the countries 

of the “nuclear club” meets nonproliferation 

requirements. 

At present, it can be considered 

theoretically proven and computationally 

experimentally substantiated 

that such three additional 

requirements for FNR, as IBR close 

to 1 [5], lead coolant [6] and dense 

nitride uranium-plutonium fuel 

(MNIT-fuel) [7], make it possible to 

significantly increase the safety 

level of FNR that meet these requirements, 

in com parison with FNR 

with IBR, significantly less than 

one (larger only when using a 

blanket), with sodium coolant and 

MOX fuel mastered in Russia. Thus, 

for a large-scale component of 

nuclear power, an FNR with a IBR 

close to unity, with lead coolant 

and dense uranium- plutonium fuel 

is required. 

1. In connection... 

with the requirement to increase the 

level of safety, in relation to the reactor 

installations of NPPs, six main 

technical solutions can be distinguished 

that ensure the satisfaction 

of the natural safety requirements of 

large-scale nuclear power, which are 

demonstrated in the BREST-OD-300 

reactor plant: The equilibrium active 

zone of FNR 

The equilibrium FNR core allows 

minimizing the reactivity margin for 

nuclear fuel burnout and virtually 

eliminating instantaneous neutron 

acceleration (Figure 1). 

2. Dense fuel 

Among the fundamental properties 

of dense fuel, three play a significant 

role in terms of influencing the basic 

characteristics of the active zones and 

safety: density, thermal conductivity, 

and the specific amount of scattering 

light elements (oxygen, carbon, and 

nitrogen). 

A higher fuel density and a smaller 

number of light elements contributes 

to an increase in the reproduction 

coefficient in the reactor core (IBR) 

and the integral BR for the reactor 

plant (RP). Special unique properties 

are acquired by active zones with the 

so-called “equilibrium” fuel, in which 

| Figure 1 

Reactivity reserve for the campaign of the BREST-OD-300. 

the burning of the fissile material is 

completely compensated by its reproduction. 

Dense fuel allows realizing an 

equilibrium core (Figure 2) with a IBR 

of about one (Table 1), that provide: 

p complete reproduction of fissile 

nuclides, which is a sufficient 

con dition for the practical use of 

the energy resource U-238; 

p work without a uranium blanket, 

which eliminates the production of 

low-background radiation with a 

quality close to weapons-grade; 

p the absence of the need to separate 

plutonium from SNF and the 

possibility of using technologies 

without separating uranium and 

plutonium, which together with 

the previous advantage provide 

technological support for the nonproliferation 

regime; 

p minimization of the burnout 

reactivity margin, which reduces 

the maximum reactivity margin of 

the reactor vessel and increases the 

nuclear safety of the reactor vessel; 

p unique stability of fuel rods and 

fuel assemblies heat release during 

their operation. 

Currently, more than 1,500 fuel rods 

have been tested in the BOR-60 and 

BN-600 rector plants, including up to 

a burn-up depth of 9.3 % t. a. 

3. Wide core grid 

The wide grid of the core allows 

having a level of natural circulation 

sufficient to remove the residual heat 

and reduce the power consumption 

for pumping the coolant. 

4. Integrated layout of the 

reactor plant 

The integrated layout of the reactor 

plant (Figure 3) allows excluding the 

loss of core cooling. 

All primary circuit equipment 

required for organizing the circulation 

circuit and transferring energy to the 

heat conversion circuit is located in a 

single reactor block. 

5. Heavy liquid metal coolant 

The choice of lead as a coolant for the 

BREST-OD-300 reactor plant stems 

from: 

p the presence of a well-founded 

lead coolant technology, i.e. a set 

of measures and means to ensure 

the required quality of the coolant 

and the cleanliness of the primary 

circuit during operation; 

p low potential energy associated 

with possible chemical reactions 

involving lead; 

p negligible moderating ability of 

lead nuclei, which, on the one 

hand, eliminates the problem of 

the positive void effect of coolant 

reactivity, and on the other hand, 

| Figure 2 

Cartogram a.z. reactor plant BREST-OD-300. 

Number of fuel assemblies in the core 169 

Core height, mm 1,100 

MNIT fuel density, g/cm 3 12.3 

Full load of MNIT fuel, t 20.8 

Max. burn-up depth in the discharged fuel 

(at the initial stage), % t. a. 

Average ST temperature at the inlet/outlet 

of the core, °C 

Average energy intensity of a.z., MWth/m 3 140 

Maximum linear power over the core, W/cm 420 

| Table 1 

Index a.z. reactor plant BREST-OD-300. 

9.3 (6.0) 

420/535 

Reproduction rate (blanket is missing) 1.05 






| Figure 3 

The view of BREST-OD-300 reactor plant. 

allows the use of a wide lattice in 

the core, thereby providing an 

effective mode of natural circulation 

of the coolant in the core with 

a simultaneous decrease in coolant 

velocity (almost twice as compared 

with sodium coolants in a sodiumcooled 

fast breeder reactor (BNreactor) 

reactor) and hydraulic 

resistance of the circulation loop 

and, as a consequence, with a reduction 

in the power consumption 

for pumping the coolant; 

p low availability of lead nuclei in 

the neutron flux, which makes it 

possible to switch from a vessel 

structure to a pool structure, 

charac terized by a high heat capacity, 

and place the equipment in a 

concrete shaft lined with steel 

or cast iron compatible with lead, 

with a decrease in the cost of a 

reactor installation and an increase 

in reactor safety in transient and 

emergency processes due to the 

thermal inertia of the circuit; 

p high boiling point (~ 1745 °C) of 

the lead coolant, which excludes 

accidents associated with the crisis 

of heat exchange (in the reactor, 

due to the higher pressure in the 

core, the boiling point of lead can 

reach 2300 °C). 

The above benefits are illustrated in 

Figures 4 and 5. 

The figures are given for the worst 

conditions of heat removal from the 

reactor core – complete blackout. 

There is a shutdown of four reactor 

coolant pumps (RCPs) and a cessation 

of feed water supply during operation 

at the initial nominal power. The 

removal of the residual energy release 

is carried out by two of the four 

emergency core cooling systems 

(ECCSs) loops (the failure of the other 

two ECCS loops and the failure of the 

ECCS is postulated). 

Result: for all standardized 

radionuclides, emissions into the 

atmo sphere do not reach the control 

level per day. 

6. Using ambient air 

as an aftercooler 

Use of atmospheric air as a final cooler 

without intermediate circuits in the 

case of natural circulation removal of 

residual heat in a high-power reactor 

plant (Figure 6). 

In addition to the safety requirements 

for nuclear power plants, there 

are a number of requirements for 

closed NFC technologies, which 

are implemented at the Industrial 

pilot facility with a power complex 

with the BREST OD-300 reactor, a 

plant for the production of nuclear 

fuel from the products of reprocessing 

of spent nuclear fuel and a 

plant for repro cessing spent nuclear 

fuel: 

p low-waste reprocessing spent 

nuclear fuel from FNR; 

p involvement of SNF reprocessing 

products from thermal reactors 

into the nuclear reactor fuel cycle; 

p reduction of the duration the spent 

nuclear fuel spends on the nuclear 

reactor before its reprocessing to 

1 – 2 years; 

p ensuring the radiation balance 

between the extracted fuel raw 

materials and the buried radioactive 

waste (RW); 

p technological support for the 

nonproliferation regime. 

| Figure 4 

Change in power (1) and flow through the reactor (2). 

| Figure 5 

Temperature change of fuel (1) and fuel element cladding (2). 




| Figure 6 

ECCS plan. 

In connection with the requirements 

for the technologies of the closed 

NFC, three technical solutions can 

be distinguished: 

p “dry” reprocessing of spent 

nuclear fuel from FNR to reduce 

the duration of spent nuclear fuel 

holding before reprocessing and to 

exclude the separation of pure 

plutonium during reprocessing; 

p transmutation of minor actinides 

in FNR to ensure a balance 

between the extracted fuel raw 

material and the disposed radioactive 

waste; 

p abandonment of the blanket in 

FNR to exclude the production of 

weapon-grade plutonium (when 

exporting technologies). 

The question remaining is competitiveness 

of NPPs in general and on the 

basis of FNR in particular. Obviously, 

without norms and standards corresponding 

with the new technological 

nuclear power platform the solution 

of this question is difficult. The first 

approach to the answer about the feasibility 

of competitive CNFC power 

engineering based on fast neutron reactors 

will be given by conceptual projects 

of industrial power facilities with 

reactor plants BN-1200 and BR-1200. 

balance between the extracted fuel 

raw material and buried RAW) are 

preferable for the large-scale 

nuclear power engineering in 

general. 

3. To prove the advantages of reactors 

with lead coolant, a pilot demonstration 

power complex is being 

created at the site of JSC Siberian 

Chemical Combine (SKhK). 

4. Answers to the questions related to 

the industrial production and 

application of MNIT fuel for the 

IPF on the BN-1200 and BR-1200 

basis can be given only in case of its 

pilot application in the BREST- 

OD-300 reactor plant of the industrial 

pilot facility. 

5. Answers to the questions related to 

the industrial reprocessing of 

MNIT-SNF for the isotope production 

facilities (IPF) can be given 

only in the operation of the 

processing module on the pilot 

demonstration facility. 

6. Technological support of the nonproliferation 

regime in the export 

version of natural safety technologies 

is not a complete solution to 

the nonproliferation problem but 

only an important addition to 

institutional tools of its solution. 

7. For a radical solution to the CO 2 

problem, it is possible to develop a 

large-scale nuclear power industry 

by the end of this century, which 

means a gradual transition to FNRs 

with closed NFC in the nearest 

future. 

8. The main requirement for the 

development of the nuclear power 

industry is its competitiveness, 

primarily with the generation 

based on organic fuels and with 

renewable energy sources in terms 

of exports. Preliminary calculations 

for industrial power complexes 

with fast reactors operating 

in a closed fuel cycle show the 

possibility of achieving parity with 

other types of generation. 

RP 

RW 

SNF 

TR 

VVER 

Reactor Plant 

Radioactive Waste 

Spent Nuclear Fuel 

Thermal Reactor 

Water-Water Energetic Reactor 

Preferences 

[1] New Technological Platform for the National Nuclear Energy 

Strategy Development / Adamov E.O., Rachkov V.I. // Russian 

Academy of Sciences Bulletin. 

Energy. – 2017.– No. 2. – P. 3-12. 

[2] Development Strategy of the Russian Nuclear Power Industry 

for the First Half of the XXI Century. Main Provisions, Minatom 

Rossii, Moscow, 2000. – 26 p. 

[3] E. O. Adamov, A. V. Dzhalavyan, A. V. Lopatkin, 

N. A. Molokanov, E. V. Murav’ev, V. V. Orlov, S. G. Kalyakin, 

V. I. Rachkov, V. M. Troyanov, E. N. Avrorin, V. B. Ivanov, and 

R. M. Aleksakhin, Conceptual Provisions of the Development 

Strategy of the Russian Nuclear Power Industry in Prospect up 

to 2100 - NIKIET, Moscow, 2012. – 61 p. 

[4] Energy strategy of Russia for the period up to 2030 

[approved. by order of the Government of the Russian 

Federation of November 13, 2009 No. 1715-r]. 

[5] E. O. Adamov, et al., White Book of Nuclear Power 

Engineering – NIKIET, Moscow, 2001. – 496 p. 

[6] E. O. Adamov, V. I. Rachkov, et al., “Choice of coolant for 

nuclear power plant with inherent safety,” Izv. Ross. Akad. 

Nauk Energ., No. 6, 3 − 14, 2015 

[7] E. O. Adamov, L. M. Zabud’ko, V. I. Matveev, V. I. Rachkov, V. 

M. Troyanov, Yu. S. Khomyakov, and V. N. Leonov, 

“ Comparative study of advantages and disadvantages of the 

use of metal and mixed nitride uranium- plutonium fuel in fast 

reactors,” Izv. Ross. Akad. Nauk., Energ., No. 2, 3 − 15, 2015. 

Authors 

Vadim Lemehov 

Chief Designer and 

Technical Committee 

member of the Proryv 

Project* 

rvi@proryv2020.ru 

Valeriy Rachkov 

Research and Development 

Chief Scientific 

Officer of the Proryv 

Project* as well as 

Technical Committee 

member 


Conclusions 

1. A large-scale element of twocomponent 

nuclear power engineering, 

i.e. a closed nuclear fuel 

cycle FNR, requires an FNR with 

the inner breeding rate close to 1 

with a lead coolant and dense 

uranium- plutonium fuel to ensure 

the necessary safety level. 

2. Low-waste “dry” SNF reprocessing 

(mainly to reduce a duration of the 

SNF conditioning before its reprocessing) 

and minor actinide transmutation 

(to ensure a radiation 

Abbreviations 

BN Sodium-Cooled Fast Breeder Reactor 

BR Breeding Ratio 

CFC Closed fuel cycle 

ECCS Emergency Core Cooling Systems 

FNR Fast-Neutron Reactor 

HLW High Level Waste 

IBR Inner Breeding Ratio 

IPF Isotope Production Facilities 

LWR Light Water Reactor 

MA Minor Actinides 

MNIT Mixed Uranium-Plutonium Nitride Fuel 

NES Nuclear energy system 

NFC Nuclear Fuel Cycle 

NPP Nuclear Power Plant 

RCP Reactor Coolant Pump 

* Proryv project 

is implemented 

by Rosatom 




46 

AT A GLANCE 

Nuclear Innovation Alliance (NIA) 

The Nuclear Innovation Alliance (NIA) is focused on championing cuttingedge 

solutions to the climate challenges of this century. NIA is a non- partisan, 

non-profit, “think-and-do” tank working to ensure advanced nuclear energy 

can be a part of the climate solution. By engaging with policymakers, 

industry, and other stakeholders, NIA works on licensing modernization, 

policy development, and industry commercialization to bring economicallycompetitive, 

zero-carbon energy to U.S. and global markets. Advanced 

nuclear energy technologies face economic, political, and social obstacles 

to successful development, demonstration, and commercialization. NIA 

believes these obstacles can be overcome by encouraging public and private 

investment in advanced nuclear innovation at a scale adequate to drive 

meaningful innovation, and by building strong public trust in emerging 

technologies through collaboration among industry, government, labor, and 

civil society. 

NIA approaches its education and engagement efforts 

thoughtfully, by producing technically-informed analysis 

and policy recommendations for policymakers, investors, 

and members of the public. It informs licensing 

moder nization efforts at the U.S. Nuclear Regulatory 

Com mission (NRC), educates policymakers in the 

legislative and executive branches, and promotes 

commercialization through collaboration with industry. 

NIA also promotes entrepreneurialism through its annual 

Nuclear Innovation Bootcamp. 

“NIA’s highest objective is to help achieve the conditions 

for advanced nuclear energy success. We believe 

advanced nuclear energy is key to making substantial 

and identifiable progress in climate protection. NIA is an 

advocacy hub for advanced nuclear energy policy in the 

United States, and is building a durable and sustainable 

organization with an expanding base of support,” says 

Judi Greenwald, NIA Executive Director. 

Currently, NIA is primarily funded through charitable 

grants and philanthropic donations from climateconcerned 

individuals and foundations. With its strong 

policy research base, NIA regularly works with policymakers 

and fellow NGOs, including The Breakthrough 

Institute, Clean Air Task Force, ClearPath, Good Energy 

Collective, and Third Way. The organization also reaches 

out into the broader nuclear energy ecosystem by 

actively engaging with advanced nuclear developers 

and investors, as well as universities, national laboratories, 

and other technical research institutions. More 

recently, NIA has also begun to work collaboratively with 

stakeholders outside of the nuclear sector, including 

environmentalists, other clean energy industries, labor, 

and energy consumers. 

History 

NIA was created in 2015 after the Clean Air Task Force 

spun off its advanced nuclear program under Dr. Ashley 

Finan into a separate organization. Under Dr. Finan’s 

leadership, NIA quickly emerged as a leader in analysis, 

stakeholder convening, and advocacy for advanced 

reactors. Through a mix of coordination, reports, and 

Congressional testimony, NIA played a major role in the 

development and passage of two major pieces of 

legislation: 

The Nuclear Ecosystem and the NIA’s Role in Innovation 

P The Nuclear Energy Innovation and Modernization 

Act (NEIMA), which required reforms at the NRC to 

facilitate the licensing of advanced reactors, including 

the development of a risk-informed, performancebased, 

technology-inclusive pathway. 

P The Nuclear Energy Innovation and Capabilities Act 

(NEICA), to support U.S. Department of Energy 

research activities and to ensure national research 

assets facilitate private innovation. 

At a Glance 

Nuclear Innovation Alliance (NIA)


Beyond these two major successes, the NIA also worked 

on nuclear export control reform, nuclear energy geopolitics, 

and other priority areas for the industry. 

In 2019, Dr. Finan departed NIA to head Idaho National 

Laboratory’s newly formed Nuclear Reactor Innovation 

Center, an institution created by NEICA. In 2020, Judi 

Greenwald was selected to replace Dr. Finan, bringing an 

extensive background in energy and environmental 

policy leadership in Washington, DC. Recently, NIA has 

grown its staff as the pace of licensing modernization 

and commercialization for advanced reactors grows. 

From one employee at its founding, NIA is set to reach 

four employees in summer 2021, supported by fellows 

and outside consultants. 

Building on its success in helping pass NEIMA, NIA is 

pursuing an ambitious research agenda to inform 

licensing modernization at the NRC. NIA continues to 

monitor and support NRC efforts to develop Part 53, a 

performance-based licensing pathway for advanced 

reactors. NIA is also conducting research on potential 

NRC fee reforms to reduce barriers to reactor innovation, 

identifying ways to shorten the duration of NRC reviews, 

and evaluating how to make U.S. licensing compatible 

with international approaches. 

Beyond its regulatory work, NIA engages extensively 

with policymakers as they endeavor to enact and 

implement new laws to drive nuclear innovation. 

47 

AT A GLANCE 

Organization 

NIA is overseen by its Board of Directors, and consults 

with its Industry Innovation Leadership Council and 

Advisory Committee, to ensure its approach to achieving 

conditions for success encompasses a broad range of 

interests and perspectives, including investors, government 

leadership, and the public. 

NIA’s Industry Council is a forum for advanced reactor 

developers to discuss innovation challenges and opportunities. 

Reformed in early 2021, the Council informs the 

NIA’s strategy and activities but does not set NIA policy. 

The current members of the Council include leading 

advanced reactor developers in the U.S.: 

P BWX Technologies, Inc. 

P Framatome, 

P GE Hitachi 

P General Atomics 

P Holtec 

P Kairos 

P NuScale 

P Oklo 

P Terrapower 

P Terrestrial Energy USA 

P Ultra Safe Nuclear Corporation 

P Westinghouse 

P X-Energy 

Ongoing Activities 

Today, NIA is engaged in many activities to catalyze the 

development of advanced nuclear energy. In February, 

NIA and the Partnership for Global Security released a 

joint strategy for U.S. leadership on commercialization of 

advanced reactors. The report, titled “U.S. Advanced 

Nuclear Energy Strategy for Domestic Prosperity, Climate 

Protection, National Security, and Global Leadership,” 

details a whole-of-society approach; with collaboration 

between government, industry, civil society, and other 

nations that can bring advanced reactors to market to 

reduce global emissions, provide domestic jobs, and 

support national security. The Strategy and other reports 

by NIA are available on the NIA website. 

Nuclear Innovation Bootcamp 

NIA is a proud sponsor and organizing partner of the 

Nuclear Innovation Bootcamp, an annual workshop that 

introduces select students and early career professionals 

to advanced nuclear energy and the 21st century energy 

landscape. Over the span of two weeks, participants 

engage in multi-disciplinary classes and workshops 

delivered by a broad array of presenters, all while 

developing group ventures that are ultimately pitched to 

industry leaders. Past Bootcamps have incorporated a 

diverse range of topics including technology, marketing, 

policy, and public relations. Bootcamp alumni are active 

across industry, academia, and the policy space. 

In 2016, the first Nuclear Innovation Bootcamp was held. 

The program convened twenty-five students from 

around the world at UC Berkeley, where the students 

developed and pitched nuclear start-up concepts to a 

panel of judges. Using lessons learned from the inaugural 

edition, the program format was enhanced and 

remained at UC Berkeley for the following two years. In 

2019, the Bootcamp, “Atoms in Action,” was hosted at 

the OECD Nuclear Energy Agency in Paris, France. 

Twenty- seven students and young professionals from 

10 countries and 4 continents took part that year, the 

Bootcamp’s first edition in Europe. While there, they 

drew upon experience from the established French 

nuclear industry and learned about exciting developments 

taking place in the European advanced nuclear 

sphere. 

In light of the COVID-19 pandemic, the 2020 Bootcamp’s 

programming was abbreviated, moved online, and 

opened to past alumni. Due to ongoing public health 

concerns and travel restrictions, the NIA and other 

cooperating organizations are looking to build on the 

success of the 2020 online experience and develop an 

equally engaging program for 2021. 

Contact 

www.nuclearinnovationalliance.org 

@theNIAorg 

At a Glance 

Nuclear Innovation Alliance (NIA)


48 

ENVIRONMENT AND SAFETY 

Safety-related Residual Heat Removal 

Chains of German Technology Pressure 

Water Reactors (Light and Heavy Water) 

Franz Stuhlmüller and Rafael Macián-Juan 

Introduction The Nuclear Power Plants (NPPs) with Pressure Water Reactor for enriched fuel (PLWR, Pressurized 

Light Water Reactor) and for natural uranium (PHWR, Pressurized Heavy Water Reactor), developed in Germany, are 

largely identical in their basic design. However, there is a striking difference in the scope of the main reactor systems. 

While in PLWR these only consist of Reactor and Reactor Coolant System including Pressurizer and Pressurizer Relief 

Tank, in PHWR the Moderator System is added. In power operation of a PLWR, the entire thermal reactor power is 

transferred to the water/steam cycle via the Steam Generators. In PHWR, on the other hand, part of the power has to be 

removed - at a lower temperature level - from the moderator, which is spatially separated from the main reactor coolant 

within the Reactor Pressure Vessel, but is kept at the same pressure via function-related compensating openings. This 

portion of power is used to preheat the feed water before it enters the Steam Generators. The Moderator System 

installed for this purpose can also be used in a second function as the inner link in the Residual Heat Removal Chain 

(RHRC) for cooling the Reactor after it has been switched off. In PLWR the analog system is operated exclusively for the 

removal of residual heat from the Reactor and, if necessary, the Fuel Pool. In the following, the development steps of the 

RHRC of both NPP lines are shown and the main differences between both NPP-types in this regard are explained by 

comparing the most recently erected plants, DWR 1300 MW (KONVOI) and Atucha 2. 

*In the case of sump 

operation after loss of 

coolant, the extraction 

does not take place 

from the reactor system, 

but from the floor 

(sump) of the Reactor 

Building Interior. With 

the PLWR, this is 

achieved by switching 

to a separate suction 

line in the intake to the 

Residual Heat Removal 

Pump. The PHWR uses 

the Safety Injection 

Pump for this – possibly 

in parallel operation 

with the Moderator 

Pump – which thus 

becomes part of the 

RHRC. In the further 

explanations and 

figures these RHRC 

special variants are not 

considered. 

Residual Heat Removal Chain, 

Structure and Terms 

Figure 1 shows the basic structure of 

the RHRC using the example of a plant 

with four cooling lines, as is the case 

with DWR 1300 MW and Atucha 2 

(CNA 2). The figure also illustrates the 

terms “system” (or “RHR link”), “subsystem”, 

“RHR line” (resp. “redundancy”) 

and “RHR Chain”. While a 

“system” contains the entirety of all 

“subsystems” of an RHR link (horizontal 

unit), each “RHR line” is made up 

of three contiguous subsystems, from 

heat source to heat sink (vertical unit). 

All RHR lines together form the “RHR 

Chain” (although in normal usage a 

chain is understood to mean what is 

referred to here as a line). 

(Redundancy) 

Line 

Removal 

Heat 

Residual 

Residual Heat 

Removal 

System/ 

Moderator- 

System 

Safety Component 

Cooling System/ 

RHR Intermediate 

Cooling System 

Secured Service 

Cooling Water 

System 

1 

2 

3 4 

5 

Subsystem 

1 

2 

3 4 

5 

Reactor 

Heat Sink 

1 

2 

3 4 

5 

The RHRC thus consists of three 

procedural systems, namely 

p a circulation system for reactor 

coolant or moderator, connected 

to the reactor cooling loops or 

directly to the Reactor Pressure 

Vessel*, 

p an intermediate cooling system, 

which takes heat from it in heat 

exchangers, and 

p transfers it in other heat exchangers 

via the Secured Service 

Cooling Water System to the external 

heat sink. “Secured” expresses 

that the system – like the entire 

RHRC – has a fail-safe design and 

that its electrical units can be 

operated via the NPPs Emergency 

Power Supply, if necessary. 

1 

2 

3 4 

5 

Residual Heat Removal Chain 

1 

2 

3 

4 

5 

Residual Heat Removal Pump/ 

Moderator Pump 

Residual Heat Exchanger/ 

Moderator Cooler 

Component Cooling Pump/ 

RHR Intermediate Cooling Pump 

Component Cooling 

Heat Exchanger/ 

RHR Intermediate Cooling 

Heat Exchanger 

Secured Service Cooling 

Water Pump 

| Figure 1 

Residual Heat Removal from the Reactor; Definition of “System” (or “RHR link”), “Sub-System”, 

“RHR Line” and “RHR Chain”. 

Temporal Development 

of the RHRC 

The development steps up to the latest 

versions of the RHRC for PLWR and 

PHWR go hand in hand with the 

chronological growth of the unit sizes 

of both NPP variants from the second 

half of the 1960s to the end of the 

1980s (Figure 2). 

Starting with MZFR (multi- purpose 

research reactor Karlsruhe) as a prototype 

NPP of a PHWR and KWO 

(Obrigheim nuclear power plant) as a 

PLWR demonstration plant, the unit 

power outputs increased with almost 

constant gradients, 

p at the PLWR version via KKS ( Stade 

nuclear power plant) to the KWB-A 

plant (Biblis nuclear power plant, 

Unit A). This was followed by a 

consolidation phase with the 

construction of several (1200 to) 

1300 MWel class NPPs (before 

the step towards an EPR size of 

≥ 1600 MWel was taken), 

p at the PHWR with a significantly 

flatter course via Atucha 1 (CNA 1) 

to CNA 2 plant as the last NPP of 

this type to date. 

Hereinafter, the RHRC concepts of all 

of the above power plants (without 

EPR) are shown in their original 

version. Later retrofittings, e.g. as 

adaptation measures to tightened 

safety regulations are not considered. 

In the first plants – both PLWR and 

PHWR – the single-line concept or 

multi-line in meshed construction was 

common for the systems of the RHRC. 

Here e. g. cross-connections between 

individual subsystems of an RHR link 


Safety-related Residual Heat Removal Chains of German Technology Pressure Water Reactors (Light and Heavy Water) ı Franz Stuhlmüller and Rafael Macián-Juan


| Figure 2 

Temporal Development of unit net power of german-type PLWR and PHWR plants. 

are established, via which, if necessary, 

a standby pump can optionally be 

connected to several circuits. However, 

this design pre supposes that failure of 

passive system parts, such as piping, 

does not have to be assumed. The 

extension of scenarios to be controlled, 

in particular the postulate that in the 

event of an accident, in addition to 

the maintenance or repair of a component, 

a single failure also occurs on 

any system part, led to transition to 

the completely line-separated concept 

with three or four RHR-lines for the 

RHRC, depending on the unit size. This 

change took place step by step for both 

types of NPP, with the line separation 

developing from the inner to the outer 

link of the cooling chain, i.e. starting 

with the Moderator System (PHWR) 

resp. the Residual Heat Removal 

System (PLWR) up to the Secured 

Service Cooling Water System. 

The following descriptions are 

exclusively in the present form, also 

for the plants that have already been 

decommissioned. 

NPPs with Pressurized Light 

Water Reactor 

Immediately after switching off a 

PLWR power plant, cooling of the 

reactor system basically takes place 

via the Steam Generators (exception: 

loss of coolant accidents above certain 

leak sizes). At the time, when cooling 

is taken over by the RHRC, pressure 

and temperature of the reactor cooling 

circuit have already been reduced to 

such an extent, that the design values 

for the Residual Heat Removal System 

can be kept significantly lower than 

those of the reactor system. The heat 

to be removed has sunk so far, that an 

intermediate cooling system, designed 

for low temperature and low pressure, 

can be used on the secondary side of 

the Residual Heat Exchanger. This 

intermediate cooling system (called 

“Component Cooling System”) supplies 

further safety- related and operational 

cooling points in parallel to the 

Residual Heat Exchanger. If the RHRC 

has a multi-line structure at least up to 

and including the Component Cooling 

System, then two component cooling 

subsystems are designed so that – 

alternating – they can supply cooling 

water to all of the operational cooling 

consumers (e.g. of Reactor Coolant 

Pumps and nuclear auxiliary systems) 

in addition to their line- associated 

safety-related cooling points. 

NPP Obrigheim (KWO), 

283 MWel 

The RHRC is formed from one line, 

i. e. each RHR link from one circuit. 

The Residual Heat Removal System 

here includes two Residual Heat 

SG 

RCP 

3 

5 

Reactor 

4 7 

6 

1 

2 

8 

SG 

RCP 

| Figure 3 

KWO, Reactor Coolant System and RHR Chain. 

Removal Pumps connected in parallel 

and two Residual Heat Exchangers, 

both of which are integrated on their 

secondary side in the single component 

cooling circuit [1]. 

Special features of KWO are: 

p The additional use of the Residual 

Heat Exchangers as low-pressure 

coolers within the Volume Control 

System (not shown in Figure 3), 

p Two Emergency Secured Service 

Cooling Water Pumps (in addition 

to the regular two Secured Service 

Cooling Water Pumps). 

NPP Stade (KKS), 630 MWel 

The Residual Heat Removal System as 

the inner link of the RHRC is carried 

out in two subsystems, but is still 

mesh-designed with one Residual 

Heat Exchanger und two Residual 

Heat Removal Pumps each [2], [3], 

[4]. The other two RHR links consist – 

like at KWO – of only one circulation 

system each, but with special features. 

These are: 

p Three Component Cooling Pumps, 

p Three Component Cooling Heat 

Exchangers connected in parallel 

(which were probably activated as 

required), 

p Two additional Emergency Component 

Cooling Pumps (not shown 

in Figure 4), 

p Three Service Cooling Water 

Pumps. 

NPP Biblis Unit A (KWB-A), 

1150 MWel 

With KWB-A, already in 1975 the 

RHRC took the shape, which subsequently 

– with a few safety-relevant 

additions – became the standard and 

Main Steam System 

Reactor Coolant System 

Residual Heat 

Removal System 


System 


Cooling Water System 

SG Steam Generator 


1 

2 

3 

4 

5 

6 

7 

8 

Residual Heat Removal Pumps 

Residual Heat Exchangers 

Component Cooling Pump(s) 




Cooling Water Pumps 

Emergency Secured 

Service Cooling Water Pumps 

Further Component Cooling 

Water Consumers 

Further Secured Service 

Cooling Water Consumers 

ENVIRONMENT AND SAFETY 49 





SG 

RCP 

3 

5 

4 

SG 

2 

4 

Reactor 

RCP 

RCP 

has since been used for all following 

PLWR plants [5], [6]. The number of 

RHR lines usually, but not necessarily, 

corresponds to the number of reactor 

cooling loops. For this size of units 

(and also for the EPR concept 

(≥ 1600 MWel) four Steam Generators 

and thus four reactor cooling 

loops are required for heat transfer to 

the water/steam cycle in power operation. 

Accordingly, the RHRC also 

consists of four independent RHR 

lines with a heat transfer capacity of 

50 % each, based on the design case. 

1 

6 

4 

RCP 

2 

SG 

| Figure 4 

KKS, Reactor Coolant System and RHR Chain. 

SG 



Residual Heat 



System 





1 

2 

3 

4 

5 

6 



Component Cooling Pumps 


Heat Exchangers 





(Note: Even for plants with only three 

reactor cooling loops, this “one to 

one” assignment of loop and line 

number can be obtained without 

violating the safety philo sophy (repair 

and simultaneously single-failure) 

when the heat transfer capacity of 

each line is increased to 100 %.) In 

Figure 5, the two inner component 

cooling circuits are designed for the 

alternating supply of operational 

component points. For this purpose, 

in addition to the regular Component 

Cooling Pump, a second pump is 

connected in parallel, operated in case 

of a very high cooling water demand. 

NPPs of DWR 1300 MW class 

The increasing safety-related requirements, 

set down e. g. in the “RSK 

Guidelines for Pressurized Water 

Reactors” [7] and in “Safety Regulations 

of the KTA” [8], [9], in 

particular 

p elevated awareness of the fuel pool 

inventory as a source of activity, 

and 

p the inclusion of “civilizationrelated 

external impacts” (aircraft 

crash, explosion pressure waves, 

third part influences) as cases to be 

managed, 

led to important extensions for the 

system technology of the steam 

generator feed as well as for the RHRC 

[10]. 

With the Emergency Feed Water 

System, a possibility of short- and 

medium-term heat removal from the 

Reactor Coolant System via the Steam 

Generators was created, independent 

of the Feed Water Tank and the regular 

Emergency Power Supply. For the 

subsequent long-term cooling via the 

so-called Emergency Cooling Chain 

(ECC) in this two of the four RHR 

lines, whose residual heat removal 

circuits contain a Fuel Pool Cooling 

Pump, 

p an Emergency Component Cooling 

Pump within the Safety Component 

Cooling System*, and 

p an Emergency Secured Service 

Cooling Water Pump in the Secured 

Service Cooling Water System. 

Operational 

Cooling points 

Reactor Reactor 

Building Building 

Interior Annulus 

Reactor 

Auxiliary 

Building 

SG 



Residual Heat 



System (safety-related part) 


System (operational part) 



Steam Generator 


1 

2 

3 

4 

5 

6 










7 Further Secured Service 


| Figure 5 

KWB-A, Reactor Coolant System and RHR Chain. 




Emergency Feed 

Water System 

1 

8 9 10 

G 

11 

SG 

4 

1a 

2 

RCP 

5 

SG 

are installed in parallel to the existing 

pumps. 

The Fuel Pool Cooling Pumps 

themselves act as “Emergency Residual 

Heat Removal Pumps” as part of 

the Residual Heat Removal System in 

this case. If required, all this pumps 

are supplied with power via the 

Emergency Generators, which – after 

the Emergency Feed Water Pumps 

have been disconnected – are driven 

by the Emergency Diesel Engines. 

For the fuel pool cooling, in 

addition to the two RHR lines that 

include the Fuel Pool Cooling Pumps, 

there is also another fuel pool cooling 

circuit whose single cooler is supplied 

by the Operation Component Cooling 

System*. 

NPPs with Pressurized Heavy 

Water Reactor 

The function of the Moderator System 

in power operation of the plant 

requires identical pressure and 

temperature design values as for the 

Reactor Coolant System itself. However, 

this also opens up the possibility 

– by switching over valves inside 

the Moderator System and with an 

appropriate design of the RHR Intermediate 

Cooling System as the middle 

link of the RHRC – to take over the 

cooling of the reactor immediately 

after shut down, even without additional 

Steam Generator feed. This 

option has not yet been implemented 

for the MZFR as the first PHWR plant. 

Only CNA 1 and CNA 2 are equipped 

with a high pressure/high temperature 

designed RHRC and are therefore 

independent of the function of the 

main heat sink (steam turbine condenser) 

for cooling down the plant 

1 

2 

RCP 

5 

Reactor 

after all shut-down occasions to be 

assumed. 

Multi-purpose research reactor 

Karlsruhe (MZFR), 50 MWel 

The shutdown concept of the MZFR 

basically corresponds to that of PLWR 

plants, with priority on the Steam 

Generators [11]. Only when this – 

below a certain coolant temperature – 

is no longer thermodynamically 

possible, switch over to RHRC operation 

has to be performed for further 

cooling of the plant. Moderator temperature 

and heat to be removed at 

this time are already so low that the 

SG 

From 

Condenser 

Cooling 

Tower 

RCP 

5 

RCP 

3 

5 

RCP 

3. Fuel Pool 

7 4 7 Cooler 7 4 7 4 

SG 

1 

Reactor 

4 

SG 

2 2 

G 

G 

6 6 Reactor 

6 

Building 

11 

Annulus 

11 

3a 3 

3 

3 3 

5a 


Water System 

8 9 10 

Operational 

Cooling points 


Building Auxiliary 

Interior Building 

| Figure 6 

DWR 1300 MW, Reactor Coolant System and RHR Chain. 


Water System 

10 9 8 

5 

1a 

6 

3a 

5a 

SG 

RCP 

1 

1 

10 

2 

Feedwater 

System 

5 7 

| Figure 7 

MZFR, Reactor Coolant System and RHR Chain. 


Water System 

9 8 

G 

11 

Moderator Cooler on its secondary 

side can be operated with inlet 

temperatures, which are accepted by 

the other cooling points of the 

Component Cooling System without 

boiling at its outlet; even at the slight 

overpressure with which the Component 

cooling System is operated. 

A special feature of the MZFR- 

RHRC is that the operating pressure in 

the Secured Service Cooling Water is 

higher than in the system. In the event 

of a heat tube leak in the Component 

Cooling Heat Exchanger, transition 

of possibly radioactive contaminated 

water to the environment is thereby 

6 



Residual Heat 


Safety Component 






1 Residual Heat Removal Pumps 

1a Fuel Pool Cooling Pumps 

2 Residual Heat Exchangers 

3 Component Cooling Pumps 

3a Emergency Component 

Cooling Pumps 

4 

Operation Component 




SG 



Moderator System 


System 





1 Moderator Pumps 

2 Moderator Coolers 

3 Component Cooling Pump(s) 

4 Component Cooling 


5 Secured Service 


6 Further Component Cooling 


7 Further Secured Service 




5a Emergency Secured Service 


6 

Safety-related Cooling Points 

7 Secured Intermediate Coolers 

8 Emergency Feed Water Pumps 

9 Emergency Generators 

10 Emergency Diesel Engines 

11 Demineralized 

Water Pool 

*With introduction of the 

new “Power Plant 

Labeling System (KKS)” 

in 1976 the Component 

Cooling System was, 

without any technical 

impact, split into “Safety 


System” and “Operation 


System”. The former 

includes the Component 

Cooling Pumps, 

the Component Cooling 

Heat Exchangers as 

well as the supply of all 

cooling points that are 

relevant for operation 

of the RHRC. The latter 

only consists of the 

connected pipe network, 

which distributes 

and collects the cooling 

water flows to consumers 

of nuclear 

operating systems 

inside Reactor- and 

Reactor Auxiliary 

Building. 






RCP 

3 

SG 

Reactor 

SG 

RCP 

2 1 

1 2 Feed Water 

System 

3 

4 4 

5 

| Figure 8 

CNA 1, Reactor Coolant System and RHR Chain. 

3 

avoided, but pollution of the demineralized 

water in the component 

cooling circuit may happen instead. In 

subsequent plants, the pressure gradation 

was implemented consistently 

from the heat source (high) to the 

heat sink (low). 

NPP Atucha 1 (CNA 1), 

319 MWel 

The Moderator System consists of two 

completely separate loops, each of 

which assigned to a circuit of the RHR 

Intermediate Cooling System [12], 

[13], [14]. Deviating from MZFR, the 

task of this system is to be able to take 

6 

Main Steam System SG Steam Generator 

Reactor Coolant System RCP Reactor Coolant Pump 

1 Moderator Pumps 


2 Moderator Coolers 

RHR Intermediate 

3 RHR Intermediate 


Cooling Pumps 


4 RHR Intermediate 

System 

Cooling Heat Exchanger 



8 

7 

9 



6 Component 

Cooling Pumps 

7 Component Cooling 


8 



9 Fuel Pool Coolers 

over the reactor cooling already 

shortly after shut down of the Reactor. 

The asso ciated temperature and 

pressure values in the system preclude 

the use of the Component Cooling 

System for heat removal; this is 

designed to only supply all other 

safety- related and the operational 

cooling points as a single circuit 

without redundancy. It is fitted out 

with two Component Cooling Heat 

Exchangers and Component Cooling 

Pumps of full capacity each. The 

RHR Intermediate Cooling System is 

equipped with a third RHR Intermediate 

Cooling Pump. In the event of 

failure of one of the two regular 

pumps this additional pump takes 

over the circulation in the affected 

circuit. The return lines of the RHR 

Intermediate Cooling Circuits cannot 

be shut off to the area around the 

Moderator Cooler flowed through by 

the feed water during power operation, 

so that the feed water pressure is 

impressed on them in their standby 

state. After the feed water lines at the 

outlet of the Moderator Cooler have 

been shut off and transition to the 

RHRC cycle operation is completed, 

the water balance in the RHR Intermediate 

Cooling Circuits (absorption 

of expansion water when heating up, 

recovery of contraction water when 

cooling down) can be carried out via 

expansion tanks as well as discharges 

to the Feed Water Tank on the one 

hand, and feed from the tank or the 

demineralized water pool by means of 

system-associated pumps on the other 

hand. 

A line assignment has not yet 

been made for the outer RHRC link, 

the Secured Service Cooling Water 

System. Three parallel Secured Service 

Cooling Water Pumps can feed a 

manifold, from which all inter coolers 

as well as the Fuel Pool Coolers are 

supplied. 

NPP Atucha 2 (CNA 2), 

692 MWel 

A clear line separation concept has 

been implemented at CNA 2. Although 

the plant only has two reactor cooling 

circuits, the Moderator System and 

the entire RHRC are constructed with 

four lines, each of them having a 

capacity of 50 % of the total power to 

| Figure 9 

CNA 2, Reactor Coolant System and RHR Chain. 



1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

Moderator Pumps 

Moderator Coolers 

RHR Intermediate Cooling Pumps 

RHR Intermediate Cooling Heat Exchangers 

Secured Service Cooling Water Pumps 


Component Cooling Heat Exchangers 

Component Cooling Water Consumers 

Fuel Pool Coolers 

Secured Intermediate Coolers 




be removed in the design case. Thus 

the “repair + single-failure” criterion 

for accidents is fulfilled. Not only the 

RHR Intermediate Cooling System, 

but also the Safety Component 

Cooling System here consists of four 

circuits, which supply the respective 

associated consumers – i. e. pumps 

and their motors – with cooling water. 

The circuits of the two outer re dundancies 

in Figure 9 can also be optionally 

switched on to cooling points of 

the fuel assembly transport devices 

(not shown in Figure 9). One circuit 

of the two inner redundancies serves 

not only its safety-relevant consumers, 

but also the Operation Component 

Cooling System, the other one stands 

by for that. The design of the RHR Intermediate 

Cooling System enables – 

if necessary – a takeover of heat transfer 

from the Reactor Cooling System 

after shut-down of the plant without 

the aid of Steam Generator feed. To 

achieve the maximum possible heat 

removal capacity, the bypasses inside 

the RHR Intermediate Cooling Circuit 

around Moderator Cooler and RHR 

Intermediate Cooling Heat Exchanger 

must be closed. If it is necessary for 

the RHRC to keep the Reactor Cooling 

System at a desired temperature state 

or to cool it down according to a 

specified shutdown gradient, this is 

done by opening/ closing the bypass 

around the Moderator Cooler and 

by controlling the flow rate through 

the primary side of the RHR Intermediate 

Cooling Heat Exchanger on 

the one hand and the bypass around 

the cooler on the other (Shutdown 

control). 

An important modification compared 

to CNA 1 is the handling of the 

water balance in the RHR Intermediate 

Cooling Circuits. Facilities 

for absorbing expansion water and 

re-feeding it when the circuit cools 

down as well as replacing operational 

medium losses (in the event of failure 

of operational demineralized water 

supply) are set up for each circuit 

self-sufficient and spatially separated 

from each other in the Reactor 

Building Annulus. 

Each of the four subsystems of the 

Secured Service Cooling Water 

System with one Secured Service 

Cooling Water Pump each, supplies all 

of the assigned heat exchangers in 

parallel, that are 

p one RHR Intermediate Cooling 

Heat Exchanger, 

p one Component Cooling Heat 

Exchanger, 

p one Secured Intermediate Cooler, 

(This heat exchanger removes the 


Water System 

1 

SG 

1a 

2 

RCP 

5 

heat loss from the line-assigned 

Emergency Diesel Engine and the 

Secured Chilled Water System, 

which is absorbed in the so-called 

Secured Closed Cooling Water 

System.) 

p One Fuel Pool Cooler (Each one of 

the two coolers is connected to two 

subsystems of the Secured Service 

Cooling Water System; this is why 

in Figure 9 and Figure 10 below – 

only to illustrate the supplyability – 

four pool coolers are drawn.) 

1 

5 

Reactor 

6 6 

Reactor 

Building 6 

6 

11 

Annulus 

11 

3a 3 

3 

3 3 3a 

3. Fuel Pool 

4 7 4 7 Cooler 

7 4 7 4 

5a 



SG 

2 

RCP 

Residual Heat Removal System 

Safety Component Cooling System 

RCP 

5 

SG 

RCP 

2 2 

8 9 10 8 9 10 

10 9 8 

10 9 8 

11 

G 


Water System 

G 

Operational 

Cooling Points 


Building Auxiliary 

Interior Building 

Comparison DWR 1300 MW – 

Atucha 2 

By comparing the RHRC configurations 

of the latest PLWR- and PHWR 

plants in Figure 10 it is intended to 

show at a glance their differences 

in the type and scope of process 

engineering equipment for the removal 

of residual heat from the 

reactor cooling system. Furthermore, 

it is marked which resp. how many 

subsystems/lines must be active 

during power operation of the plant. 

1 

G 

DWR 1300 MW 


Water System 

5 

1a 

5a 

SG 

Operation Component Cooling System 

Secured Service Cooling Water System 

| Figure 10 

DWR 1300 MW – CNA 2, Comparison of RHR Chains regarding their necessary use during power operation of the plant; 

Explanation of Numbers: see Figures 6 and 9. 

1 


Water System 

G 

11 

CNA 2 






DWR 1300 MW 

Reactor SG 

CNA 2 

Reactor 

RCP 

SG 

RCP 

6 

3 

HPT 

FWT 

HPT 

4 

M 

S 

RH 

5 

M S 

LPT 

LPT 

G 

Main Cooling 

Water 

G 

G 

SG 

RCP 

RH 

Steam Systems 



Feedwater System 

Main Condensate System 

Main Cooling Water System 


Reactor Coolant Pump 

FWT Feed Water Tank 

HPT 

LPT 

MS 

1 

2 

3 

Generator 

Reheater 

High Pressure Turbine 

Low Pressure Turbine 

Moisture Separator 

Moderator Pump 

Moderator Cooler 

Main Feedwater Pump 

1 2 

FWT 

4 

3 5 

Main Cooling 

Water 

4 

5 

6 

Low-Pressure 

Feedwater Heater 

Main Condensate Pump 

High-Pressure 

Feedwater Heater 

| Figure 11 

DWR 1300 MW – CNA 2, Comparison of Water/Steam Cycles (simplified). 

In order to complete the comparison, 

the water/steam cycle must 

also be included. By using the 

Moderator Cooler for preheating the 

feed water, the PHWR – in this 

regard – is considerably simplified in 

comparison to the PLWR (Figure 11). 

In addition to the High Pressure 

Preheaters themselves, the steam 

extraction points on the highpressure 

section of the Steam Turbine and the 

connecting steam pipes are eliminated 

for the PHWR. 

The second above item determines 

the number of pumps within the 

RHRC that are to be operated continuously, 

and thus also the electrical 

auxiliary power demand as well as the 

net efficiency. 

In Figure 10 mean: 

p Thick drawn subsystems and 

components: 

Used in power operation 

p Thin drawn subsystems and 

components: 

Operation readiness 

p Thin drawn heat exchanger edging, 

but with thick drawn flow symbol: 

Flow through its secondary side, 

but without heat input 

For DWR 1300 MW, the upper part 

of Figure 10 shows the minimum 

amount of subsystems to be operated. 

It is assumed that 

p the fuel pool cooling circuit 

connected to the Operating Component 

Cooling System is sufficient 

to maintain the fuel pool water 

under the desired temperature. 

Otherwise, one of the outer RHR 

lines would have to be operated 

with a Fuel Pool Cooling Pump, 

addi tionally or exclusively. 

p operation of only one of the four 

Secured Chilled Water Systems 

(which are redundantly supplied 

by the Secured Closed Cooling 

Water Systems) is necessary and 

therefore just one of the Secured 

Intermediate Coolers (No. 7 in 

Figure 6 and Figure 10 above) has 

to be flowed through. If this is not 

the case, then additional subsystems 

of the Secured Service 

Cooling Water System must be 

activated. 

With CNA 2, the constantly running 

Moderator Pumps mean that their 

cooling points – line-separated – 

always have to be supplied with cooling 

water via the Safety Component 

Cooling System. Therefore, all its 

subsystems as well as the entire 

Secured Service Cooling Water S ystem 

must continuously be operated. With 

regard to the heat removal capacity, 

actually only the line which is connected 

to the Operation Com ponent 

Cooling System with its permanent 

heat input is utilized, fully or only 

partially. 

The part of the RHR Intermediate 

Cooling System not flowed by feed 

water is separated and in stand-by 

condition. 

In contrast to the DWR 1300 MW, 

the fuel pool cooling in CNA 2 is 

completely independent from the heat 

removal via the RHRC. Here, the fuel 

pool cooling circuits transfer the heat 

to be removed directly to the Secured 

Service Cooling Water. 

Summary 

Development of the Residual Heat 

Removal Chain (RHRC) in NPPs with 

Pressurized Water Reactors of german 

design, from the prototype plant 

MZFR (heavy water) and the 

demonstration power plant KWO 

(light water) to the last plants erected, 

was carried out on three mutually 

independent areas: 

p PLWR and PHWR: 

Increasing requirements concerning 

plant-internal damage 

assumptions 

The assumption of failing of passive 

components and system parts 

as well as the postulate of simultaneity 

of “repair case and single 

failure” led to the (step- by-step) 




P transition from the single-line 

to the multi-line RHRC-design 

with several functionally independent 

redundancies of the 

same heat transfer capacity. In 

plants with four RHR lines – as 

is the case with the DWR 

1300 MW class as well as with 

Atucha 2 – each of the lines has 

to be equipped with a heat 

removal capacity of 50 %, based 

on the thermodynamic design 

case of the entire RHRC. 

P This goes hand in hand with 

abandoning meshing technology 

in which, for example, if 

a pump fails, a reserve unit 

can be switched to various 

subsystems of an RHR link. 

p PLWR – specific: 

Measures for emergencies “civilization-related 

external impacts” 

For the first time after the occurrence 

of accidents, in which it is no 

longer possible to feed the Steam 

Generators from the Feed Water 

Tank, the Emergency Feed Water 

System was created to remove the 

residual heat via Steam Generators, 

for the long-term range via 

the Emergency Cooling Chain 

(ECC) Chain, both of them operated 

by self-sufficient diesel engines/ 

generators. According to the safety 

requirements two Emergency 

Cooling Lines of a thermal capacity 

of 100 % each, with respect to the 

max. power to be removed, are 

sufficient. For this ECC, sub systems 

of the middle link (Safety Component 

Cooling System) and the 

outer link (Secured Service 

Cooling Water System) of the 

existing RHRC are equipped with 

additional, less powerful pumps – 

parallel to the main pumps. By 

using this two lines as ECC which 

contain a Fuel Pool Cooling Pump 

in their inner link, this aggregates 

are also deployed as “emergency 

residual heat removal pumps”. 

Both the Reactor and the Fuel Pool 

can thus be cooled via these lines. 

p PHWR – specific : 

Transition to a high-pressure/ 

high-temperature RHRC 

The residual heat removal concept 

of the MZFR as the first plant of this 

type of NPPs is largely identical 

with that from PLWR. In the first 

time after Reactor shut-down 

cooling is performed exclusively 

via the secondary side (Steam 

Generator) before the RHRC takes 

over with the Moderator System 

as the inner link. Only in the 

sub sequent plants Atucha 1 and 

Atucha 2 the fact has been utilized, 

that with the Moderator System a 

“ Residual Heat Removal System” is 

available, which is similar to the 

Reactor Cooling System regarding 

its pressure/temperature design 

values. By also designing the 

middle RHR link, the RHR Intermediate 

Cooling System, as highpressure/high-temperature 

circuits 

it was possible to create a divers 

residual heat removal option for 

the Steam Generators, with which 

reactor cooling is possible from the 

beginning – without further Steam 

Generator feeding. 

Bibliography 

[1] Lepie, G., Martin, A. 

“Aufbau der Gesamtanlage KWO” 

Atomwirtschaft, December 1968 

P. 596 – 606 

[2] Kernkraftwerk Stade 

“Tabelle: Wichtige Daten des Kernkraftwerks Stade” 

Atomwirtschaft, November 1971 

P. 586 – 590 

[3] Müller, H., Stahlschmidt, H. 

“Die Gesamtanlage des Kernkraftwerks Stade” 


P. 579 – 580 

[4] Bruhn, H. 

“Reaktorhilfs- und Nebenanlagen des KKS” 


P. 610 – 612 

[5] Huttach, A., Putschögl, G., Ritter, M. 

“Die Nuklearanlage des Kernkraftwerks Biblis” 

Atomwirtschaft, August/September 1974 

P. 420 – 430 

[6] Bald, A., Brix, O. 

“Die Dampfkraftanlage des Kernkraftwerks Biblis” 

Atomwirtschaft, August/September 1974 

P. 431 – 438 

[7] “RSK-Leitlinien für Druckwasserreaktoren” 

Original version (3 rd edition of October 14, 1981) 

with amendments of November 15, 1996 

[8] Sicherheitstechnische Regel des KTA 

“KTA 3301, Nachwärmeabfuhrsysteme 

für Leichtwasserreaktoren” 

Version 2015-11 

[9] Sicherheitstechnische Regel des KTA 

“KTA 3303, Wärmeabfuhrsysteme für Brennelementlagerbecken 

von Kernkraftwerken mit Leichtwasserreaktoren” 

Version 2015-11 

[10] Rieser, R., Brosche, D., Faber, P. 

“Planung, Errichtung und Inbetriebnahme 

des Konvoi-Leitprojektes Isar-2” 

Atomwirtschaft, June 1988 

P. 276 – 284 

[11] Bald, A., Schamburger, R. 

“Die Dampfkraftanlage”, from “MZFR Kernkraftwerk 

mit Mehrzweck-D2O-Druckkesselreaktor in Karlsruhe” 

Atomwirtschaft, July/August 1965 

P. 363 – 368 

[12] Frewer, H., Keller, W. 

“Das 340-MW-Kernkraftwerk Atucha 

mit Siemens-Natururan-Druckwasserreaktor” 

Atomwirtschaft, July 1968 

P. 350 – 358 

[13] Herzog, G., Sauerwald, K.-J. 

“Das Kernkraftwerk Atucha” 

Changed reprint from ATOM und STROM, 15 th Year, 

issue 4, April 1969 

P. 53 – 63 

[14] Hirmer, G., Seifert, W. 

“Das Kernkraftwerk Atucha” 

Elektrotechnische Zeitschrift, 

Ausgabe A (ETZ-A), Band 90, (1969) 

P. 509 – 513 

Authors 

Franz Stuhlmüller 

External Scientific 

Associate at the Chair of 

Nuclear Technology at 

the Technical University 

of Munich 

f-stuhlmueller@ 

t-online.de 

Franz Stuhlmüller studied Mechanical Engineering at 

the Rudolf-Diesel-Polytechnikum in Augsburg as well 

as Energy and Power Plant Technology at the Technical 

University of Munich. He was employed at Kraftwerk 

Union / Siemens AG in Erlangen in the field of nuclear 

power plants as well as conventional power plant 

technology. As a section manager he was responsible 

for decay power calculation and design of nuclear 

safety systems, conventionally for the development of 

advanced coal-fired combined cycle power plants as 

well as new emerging power generation technologies. 

After he retired in 2007 he was a consultant during 

completion of the Heavy Water Nuclear Power Plant 

Atucha 2 in Argentina till 2015. Since 2016 Franz is an 

External Scientific Associate at the Chair of Nuclear 

Technology at the Technical University of Munich 

(TUM). 

Prof. Rafael 

Macián-Juan, PhD 

Head of the Chair 

of Nuclear Technology 

at the Technical 

University of Munich 

rafael.macian@ 

ntech.mw.tum.de 

Prof. Rafael Macián-Juan has a Master of Science in 

Energy Engineering from the Polytechnic University of 

Valencia, Spain, as well as a Master of Science in 

Nuclear Technology and holds an PhD in Nuclear 

Technology by the Penn State University, USA. He is 

the Head of the Chair of Nuclear Technology since 

2007 at the Technical University of Munich (TUM). 

Before joining TUM, he worked at the Paul Scherrer 

Institute (PSI), Switzerland, where he carried out 

research and development in reactor thermalhydraulics 

and coupled neutronics, as well as safety 

assessments of the Swiss nuclear power plants. His 

current research interests include nuclear safety, 

multi-physics and multiscale simulation codes, 

uncertainty and sensitivity methods, experimental and 

numerical thermal-hydraulics, and safety analysis and 

development of future nuclear reactor designs. He is 

currently also visiting professor at Harbin Engineering 

University in China. 






IAEA Approach to Review the 

Applicability of the Safety Standards 

to Small Modular Reactors 


Introduction A continuously increasing interest in nuclear power, and particularly in small modular reactor (SMR) 

technologies, has been expressed over the past several years by numerous IAEA Member States particularly in 

contributing to the mitigation of climate change. Today there are over seventy (70) SMR designs under development 

according to the IAEA booklet Advances in Small Modular Reactor Technology Developments, a Supplement to IAEA 

Advanced Reactors Information System (ARIS) [5]. While SMRs are typically designed to generate electric power up to 

300 MW, many new designs are also designed for other heat production applications, such as district heating, 

desalination and hydrogen production or a combination of the former. 

SMRs present novel features and 

innovative technologies, including 

different types of coolant, nuclear fuel 

and neutron spectrums and inherent 

safety features. As for all reactors, 

SMRs shall meet the objective of 

ensuring the protection of people and 

the environment from the harmful 

effects of ionizing radiation. A key 

element of meeting this objective 

is demonstrating compliance with 

fundamental safety principles and 

safety requirements. 

The IAEA safety standards reflect a 

widely accepted extensive approach 

to ensure nuclear safety, establishing 

safety principles, requirements and 

associated guidance. The IAEA safety 

standards are Member States consensus 

based documents that have 

been developed in an iterative fashion 

and capture wider aspects of legal, 

regulatory, siting, design, construction, 

commissioning, operation, decommissioning, 

and release from 

regulatory control of nuclear facilities 

and radioactive waste management, 

including disposal. Although the IAEA 

safety standards are considered to 

be technology neutral, they are influenced 

by specific issues pertaining to 

water cooled large reactors technology 

as most of the experience and 

knowledge in the Member States 

contributing to the development of 

safety standards is based predominantly 

the existing technology. 

In recent years, the IAEA has 

undertaken various initiatives to 

review the applicability of certain 

safety standards to particular types of 

SMRs. Until now, however, the IAEA 

has not systematically assessed the 

applicability of the IAEA safety 

standards to all types of SMRs 

through out their entire lifecycle. 

Therefore, the IAEA has developed 

and is implementing an approach for 

the identification of areas of nonapplicability 

of the IAEA safety 

standards, to suggest compensatory 

measures to close any identified gaps, 

in order to address the needs of the 

Member States. 

The Early Work 

The current approach adopted by the 

IAEA builds on the early work 

performed for the preparation of the 

IAEA in TecDoc-1936 [1] establishing 

the engineering judgement necessary 

to apply the design safety requirements 

contained in SSR-2/1 (Rev. 1) 

[2] to light water cooled and 

high temperature gas cooled SMRs 

(LW-SMRs and HTG-SMRs). 

A team of international experts 

between 2016 and 2018 (see 

TecDoc-1936 [1], pg 144-145 ) was 

asked by the IAEA to perform a pilot 

study to assess, with comments, the 

applicability of SSR-2/1 (Rev. 1) [2] to 

the aforementioned SMR tech nologies 

on the basis of the following criteria: 

p Applicable as is 

p Applicable with modification 

p Applicable with interpretation 

p Not applicable 

The participants were also encouraged 

to include any recommendations 

for new criteria not covered in SSR- 

2/1 (Rev. 1) [2] and to provide technical 

rationale for their recommendations. 

Applicable with modification 

inferred the need for the text to be 

updated for the requirement to be 

applicable to the specific design, 

whereas applicable with interpretation 

inferred the need to modify 

definitions of pre-existing terminology 

to encompass the new technologies. 

The Member States’ contributions 

were merged and refined 

into one comprehensive working 

document to provide an overarching 

list of recommendations. The creation 

of this working document highlighted 

the need for the two SMR designs 

assessed to initially be discussed 

independently in reference to their 

applicability to SSR-2/1 (Rev. 1) [2]. 

The working document, in its final 

form, evaluated the applicability of 

each of the 82 design safety requirements 

established in SSR-2/1 (Rev. 1) 

[2] to LW-SMRs and HTG-SMRs. The 

initial findings from the LW-SMR 

working group were presented and 

published at an international IAEA 

conference in 2017 [4]. The working 

material developed in this manner 

was channelled into an evolving project 

report that forms the basis of 

Appendixes I and II and Annex I in 

IAEA TecDoc-1936 [1]. The IAEA 

officers responsible for the development 

of this pilot study report were 

Kristine M.. Madden and Ramsey 

Arnold of the Division of Nuclear 

Installation Safety IAEA. The results 

of the study were subsequently extensively 

used to prepare an IAEA official 

publication. The work was completed 

by a team of international experts (see 

TecDoc-1936 [1], pg 143) with IAEA 

responsible officer Palmiro Villalibre 

Ares of the Division of Nuclear Installation 

Safety in the form of 

TecDoc-1936 [1]. 

Current applicability review 

approach 

The ongoing review of applicability of 

the safety standards builds on previous 

experiences and aims to consider 

in a holistic manner whether the 

current requirements and recommendations 

for SMRs cover the safety 

issues related to the new possibilities 

opened by the novel designs or, on the 

contrary, if there are gaps that need to 

be addressed to ensure that the level 

of safety established by the IAEA 

fundamental safety principles will be 

complied with. 

The level of safety defined by the 

Safety Objective and the Safety 

Fundamentals [6] is considered as the 

departing point for the study. The 

review therefore focuses only on 

the applicability of the requirements 

and recommendations to meet the 


IAEA Approach to Review the Applicability of the Safety Standards to Small Modular Reactors ı Paula Calle Vives, Kristine Madden and Vesselina Ranguelova


overall high level of safety defined in 

the Fundamental Safety Principles: 

Safety Fundamentals (SF-1) [6]. 

It is also expected that key elements 

of the safety design approach remain 

applicable to these technologies 

although additional guidance in the 

implementation may be necessary, 

such as 

p Defence in depth 

p The elimination of high radiation 

doses to workers 

p The practical elimination of early 

release 

It is also important to clarify that the 

scope of some SSGs may be wider than 

the scope of the safety requirements. 

These SSGs reflect the best practices in 

Member States. The lack of linkage 

with safety requirements may lead to 

additional consideration on how to 

define the design objectives in terms of 

acceptability of the consequences of 

novel accident scenarios. 

To achieve this objective, the 

review approach follows four steps 

that are presented in detail in this 

publication to identify: 

p the relevant safety standards to be 

considered in the review 

p areas of novelty when compared to 

operating land-based water-cooled 

large reactors 

p gaps in the applicability of the 

safety standards to SMRs, based on 

the areas of novelty identified. 

p areas of where the safety standards 

may not be applicable or could be 

adapted for a better application 

to novel design to some SMRs, 

based on the areas of novelty 

identified. 

Identification of the relevant 

safety areas to be considered 

in the review 

The safety areas and topics considered 

in the applicability review are presented 

in the table. 

Identification of areas 

of novelty 

The first step of the applicability 

review is the identification of areas of 

novelty in the lifecycle of the SMR 

when compared with land based 

water- cooled large reactors. 

The technologies considered as 

part of the review include transportable 

SMR, micro-sized reactors water 

cooled SMRs, and non-water SMRs 

(sodium fast reactors, lead fast reactors, 

high temperature gas cooled reactors, 

molten salt reactors). 

The identification of areas of novelty 

is based on a systematic comparison 

of the characteristics of SMRs with a 

Light-water Cooled Reactor Reference 

defined as part of the project. 

The characterization of these 

technologies in terms of areas of 

novelty is developed at the onset 

based on expert knowledge, literature 

review and detailed questionnaires 

responses by technology developers, 

reflecting designers’ current practices 

and claims. This information is then 

reviewed by regulatory authorities, 

technical support organisations and 

Safety Areas 

Siting 

Design and 

Construction 

Fuel Cycle 

Waste 

Management 

Facilities and 

Decommissioning 

Safety 

Assessment 

Operation and 

Commissioning 

LMfS 

Legal and 

Regulation 

Safety Topics 

other organisations from member 

states participating in the project. 

Identification of gaps in the 

applicability of the safety 

standards to identified areas 

of novelty 

The areas of novelty identified are 

compared to the contents of the 

IAEA safety standards in terms of 

Site Evaluation for Nuclear Installations 

p Site survey and site selection 

p Consideration of external events in site evaluation for NPPs 

p Dispersion of radioactive material in site evaluation for NPPs 

Safety in Design for NPPs 

p Safety classification 

p The design of key reactor safety systems: the reactor core, the containment and associated systems and 

the reactor coolant system and associated systems 

p The design of electrical power systems 

p Instrumentation and control systems 

p The design of fuel handling and storage systems for NPPs 

p The application of the human factors engineering in the design 

p External hazards in the design 

p Internal hazards 

p Radiation protection and radioactive waste management 

p Construction for nuclear installations 

Safety of Nuclear Fuel Cycle Facilities 

p Safety of conversion facilities and uranium enrichment facilities 

p Safety of uranium fuel fabrication facilities 

p Safety of uranium and plutonium mixed oxide fuel fabrication facilities 

p Safety of nuclear fuel reprocessing facilities 

p Safety of nuclear fuel cycle research and development facilities 

p Criticality safety in the handling of fissile material 

Predisposal Management of Radioactive Waste and Decommissioning 

p Disposal of radioactive waste 

p Classification of radioactive waste 

p The safety case and safety assessment for the predisposal management of radioactive waste 

p Leadership, management and culture for safety in radioactive waste management 

p Predisposal management of radioactive waste from NPPs and research reactors 

p Storage of radioactive waste 

p The safety case and safety assessment for the disposal of radioactive waste. 

p Geological disposal of radioactive waste 

p Near surface disposal of radioactive waste 

p Decommissioning of nuclear power plants, research reactors and other nuclear fuel cycle facilities 

p Release of sites from regulatory control on termination of practices 

p Storage of spent fuel pool 

Safety Assessment for Activities and Facilities 

p The structure and content of the safety analysis report 

p The development and application to nuclear power plants of deterministic safety analysis and probabilistic 

safety analysis 

p The conduct of a periodic safety review (PSR) for an existing nuclear power plant 

Commissioning and Operations 

p Commissioning 

p Conduct of operations at nuclear power plants 

p Operational limits and conditions and operating procedures for nuclear power plants 

p Fire safety in the operation of nuclear power plants 

p Maintenance, surveillance and in-service 

p Modifications to nuclear power plants 

p Core management and fuel handling for nuclear power plants and criticality safety in the handling of 

fissile material 

p Operating experience feedback for nuclear installations 

p Ageing management and development of a programme for long term operation of nuclear power plants 

p Chemistry programme for water cooled nuclear power plants 

p The evaluation of seismic safety for nuclear installations 

p Accident management programme for a NPP 

Leadership and Management for Safety (LMfS) 

p The operating organization 

p The recruitment, qualification and training 

p The application of management systems to facilities 

p The management system for nuclear installations 

p Establishing the safety infrastructure for a nuclear power programme 

Legal and Regulation 

p Organisation etc. for regulatory body 

p Functions and processes of the regulatory body 

p Licensing process for nuclear installations regulatory control of radiactive discharges to the environment 






requirements and recommendations. 

Gaps in the safety standards may be 

associated to one or several of the following 

areas of novelty: 

p New barriers, new safety functions 

or new provisions to deliver the 

safety functions. 

p New failure mechanisms, faults, 

phenomena that could lead to the 

failure of a barrier or a provision to 

deliver a safety function. 

p Eliminated failure modes, faults, 

phenomena by design which 

may imply the need for additional 

design requirements and/or 

recommendations. 

p The use of new technologies, 

including new fuels, new coolants, 

novel safety provisions, novel 

materials and construction/manufacturing 

techniques that could 

lead to the need for additional 

requirements and/or recommendations 

(e.g. recommendations for 

fuel qualification, qualification of 

materials to higher temperatures, 

use of more corrosive coolants, etc.) 

p New operating, maintenance, 

testing, refuelling and/or wates 

management strategies. 

p New facilities and/or activities on 

site and/or off site needed to support 

the construction, ope ration 

and/or post-operation management 

of the nuclear power plant. 

To ensure exhaustivity, for each of the 

above areas, the potential gaps are 

closely examined to judge if existing 

requirements and recommendations 

are sufficiently overarching to address 

the specific differences. In some cases, 

additional and more detailed review 

may be necessary at a later stage to 

characterise and confirm the identified 

potential gaps. 

Identification of areas where 

the safety standards may not 

be applicable to (some) areas 

of novelty 

The areas of novelty identified are 

then compared to the requirements 

and recommendation in the safety 

standards. Areas of non-applicability 

in the safety standards may be associated 

to one or several of the following 

novelties: 

p Failure modes, faults, phenomena 

typically considered in light-water 

cooled reactor reference that are 

not relevant to the design, which 

may imply some requirements 

and/or recommendations may not 

be applicable 

p Safety functions and provisions to 

deliver these functions that are no 

longer needed which may imply 

some requirements and/or recommendations 

may not be applicable 

p New operating, maintenance, 

testing, refuelling and/or postoperation 

management strategies 

which may imply some requirements 

and/or recommendations 

may not be applicable 

When areas of non-applicability are 

identified, the review also considers: 

p If there are associated gaps (not 

identified in the gap review) 

p If there is sufficient experience to 

confirm that the relevant areas 

of the safety standards are not 

applicable. In some cases, claims 

may have not been confirmed by 

sufficient operating experience or 

there are still considerable uncertainties 

related to the areas of 

novelty. For these cases additional 

features may be needed in the 

design until sufficient experience is 

available. The potential nonapplicability 

and uncertainty will 

be captured in the review. 

Expected outcomes 

The IAEA expects to publish this work 

as a Safety Report providing a roadmap 

for the applicability of the IAEA 

safety standards to novel advanced 

reactors and particularly SMRs 

throughout their entire lifecycle. The 

large team of IAEA experts and international 

experts from member states 

supporting the development and implementation 

of the presented 

approach will be acknowledged in the 

Safety Report publication. 

As a secondary outcome, it may be 

possible to further analyse gaps and 

areas of non-applicability to identify 

potential pathways for resolution and 

help to build a further programme 

of work to address areas of nonapplicability 

and potential gaps. 

References 

[1] INTERNATIONAL ATOMIC ENERGY AGENCY, Applicability of 

Design Safety Requirements to Small Modular Reactor 

Technologies Intended for Near Term Deployment: Light Water 

Reactors and High Temperature Gas Cooled Reactors, IAEA 

Technical Document No. 1936, IAEA, Vienna (2021). 

[2] INTERNATIONAL ATOMIC ENERGY AGENCY, Safety of Nuclear 

Power Plants: Design, IAEA Safety Standards Series No. 

SSR-2/1 (Rev. 1), IAEA, Vienna (2016). 

[3] INTERNATIONAL ATOMIC ENERGY AGENCY, IAEA Safety 

Glossary: Terminology Used in Nuclear Safety and Radiation 

Protection (2007 Edition), IAEA, Vienna (2007). 

[4] K. Madden et al. “Applicability of IAEA Safety Standard SSR- 

2/1 to Water Cooled Small Modular Reactors”. Proceedings of 

an International Conference organized by the International 

Atomic Energy Agency held in Vienna, 6 – 9 June 2017: 

Topical Issues in Nuclear Installation Safety: Safety 

Demonstration of Advanced Water Cooled Nuclear Power 

Plants, V2. IAEA, Vienna (2018). 

[5] INTERNATIONAL ATOMIC ENERGY AGENCY, Advances in Small 

Modular Reactor Technology Developments, a Supplement to 

IAEA Advanced Reactors Information System (ARIS), IAEA 

Booklet, 2020 Edition, IAEA, Vienna (2020). 

[6] INTERNATIONAL ATOMIC ENERGY AGENCY, Fundamental 

Safety Principles, IAEA, Vienna (2006). 

Authors 

Paula Calle Vives 

(Lead Author) 

Senior Nuclear 

Safety Officer 

International Atomic 

Energy Agency 

P.Calle-Vives@iaea.org 

Paula Calle Vives is a Senior Nuclear Safety Officer at the 

IAEA and the Lead of SMRs and other cross cutting topics 

at the Safety Assessment Section. She chairs the IAEA 

Working Group on SMR Safety and leads the review of 

applicability of the IAEA Safety Standards to novel 

advanced reactors. Previously, she was the Delivery Lead 

of Advanced Nuclear Technologies at the Office for 

Nuclear Regulation (ONR), UK. As a Principal Inspector, 

she also undertook roles on regulation of new build and 

operating reactors. Before ONR, she was a Senior Safety 

Engineer working in UK operating reactors, and 

developed proba bilistic safety analysis research in France. 

Paula holds a double nuclear engineering master’s degree 

(Universidad Politécnica de Madrid and Ecole Centrale de 

Nantes) as well as an international relations master’s 

degree (University of Cambridge). 

Kristine Madden 

Associate Nuclear 

Safety Officer 


Energy Agency 

K.Madden@iaea.org 

Kristine Madden is a creative and results driven nuclear 

industry leader with over ten years of progressive leadership 

experience across a broad range of diverse industry 

segments, including deterrence, non-proliferation, nuclear 

safety, nuclear security and nuclear energy. Kristine is currently 

a Nuclear Safeguards Inspector at the Inter national 

Atomic Energy Agency (IAEA), where she also previously 

worked on SMR and emergency response initiatives 

within the Department for Nuclear Safety and Security. 

Prior to joining the IAEA, she led licensing initiatives for 

the Chernobyl ISF-2 project for Holtec International and 

was a Senior Reactor Operator, INPO Engineering Coordinator 

and Reactor Engineer at USA based nuclear power 

plants. Kristine is completing her master’s degree in International 

Relations at the University of Cambridge and 

holds a bachelor’s degree in nuclear engineering and 

radiological sciences from the University of Michigan. 

Vesselina Rangelova 

Safety Assessment 

Section Head 


Energy Agency 

V.Ranguelova@iaea.org 

Vesselina is the Head of the Safety Assessment Section, Department 

of Safety and Security at the International Atomic 

Energy Agency, managing the IAEA activities on design 

safety and safety assessment of nuclear power plants. 

Previously, she led the IAEA Operational Safety Review 

Team (OSART) to assess operational safety of Nuclear 

Power Plants in IAEA Member States. Before joi ning the 

IAEA, she was coordinating the implementation of the 

European Commission Joint Research Centre EURATOM 

research and training programme on nuclear safety and 

security. Vesselina holds a master of science degree in 

nuclear engineering from Moscow Power Engineering University 

and post graduate diploma in probabilistic safety 

assessment techniques from Manchester University. 




A Zero-power Facility as a Multi-fold 

Opportunity to Support Quick Progress 

in Innovative Reactor Development 

Bruno Merk, Dzianis Litskevich, Anna Detkina, Greg Cartland-Glover, Seddon Atknison and Mark Bankhead 

Introduction and history Nuclear has a very unique role to play in a sustainable energy future, since it is the 

only currently available technology which can assure 24/7 availability and controllability while delivering massive 

amounts of low carbon energy on demand for a net-zero future. However, in the recent decades there has not been any 

significant progress in the development of viable innovative nuclear technologies in comparison with the golden age of 

the nuclear development (1950’s-1970’s). Most new designs are iterative improvements of the nuclear technologies 

developed at that time (e. g. EPR in France, BN in Russia), or are more radical designs with little substantiation with an 

exception made for BREST-OD-300 [1], currently under development/construction [2]. Regardless of the different 

nuclear technologies studied and developed, the majority of the NPPs built around the world are still light water 

reactors. Unfortunately, light water reactor technologies have their limits due to their operational characteristics and 

cannot address major challenges which nuclear industry faces at the moment. Core points are: reducing nuclear waste, 

the availability of resources to manage assets over 100’s years and the complexity systems leading to elevated cost. To 

be accepted by both, business and public, nuclear must deliver and be cost competitive compared to other flexible, 

on-demand producing, power plants with similar financial risks applied. Thus, nuclear needs innovations to be more 

sustainable, but even more importantly, we need to regrow the trust that nuclear can deliver these innovations. Finally, 

we need innovative approaches to reduce the risks associated with nuclear power plant construction becoming complex 

mega projects. 

59 

RESEARCH AND INNOVATION 

Looking back to the most recent 

western nuclear reactors put into 

operation as well as the current new 

build projects, the demand for risk 

reduction should be evident. The time 

since the last reactor being put into 

operation in the west indicates that 

we will have a problem when we 

intend to rely on experience. 

Looking into innovative reactor 

development, the last building projects 

fall into the 1980ies, followed by 

very mixed levels of success on operation. 

The German THTR project to 

build an industrial demonstrator for 

high temperature reactor technology 

lasted from 1971 to 1985 with the 

permanent shutdown in 1988. The 

French SUPERPHENIX construction 

took from 1976 to 1985 and the 

reactor was permanently shutdown 

1998 never delivering an Energy 

Availability Factor above 33 % and 

most of the time below 15 %. The 

UK fast reactor project in Dounreay 

indicates comparable dates and outcomes, 

construction started in 1966, 

Country 

Western Reactors 

under construction 

first criticality in 1974 with a load 

factor of below 30 % and the shutdown 

in 1994 (all data from [3]). 

Obviously, if we want to be successful 

in delivering innovative reactors, 

we need to learn again, and this 

should happen in a smart way. The 

key will be to receive timely feedback/ 

quick response on the decisions made 

instead of the long lead times which 

results typically in high costs when 

late adaptions are required, see e. g. 

the Olkiluoto or the Vogtle project, 

where changes in the later construction 

phase have not only led to higher 

costs but also to massive time delays 

which is maybe even more important. 

To support the required learning, 

we need an innovative and efficient 

approach, start smart and small – 

looking back to early reactor developments, 

zero/low power reactors have 

been used as a test bed for the next 

steps [5, 6] which seems to be highly 

promising. The main challenge will be 

to make the best out of the money and 

to use the time wisely. 

Reactor 

type 

Construction 

start year 

USA Watts Bar-1 WH 4LP 1973 1996 

USA River Bend GE BWR 1977 1985 

France Chooz B N4 1984 1996 

France Civaux N4 1988 1997 

USA Watts Bar-2 WH 4LP 1973/2007 2016 

| Table 1 

The last constructed nuclear power plants and their grid connection [3]. 

Grid 

connection 

p How is starting small possible 

in a highly complex multi-billion 

industry? 

p How did we do this in the 50ies and 

60ies? Can we repeat this? What 

do we need to do differently in the 

21 st century? 

p How important are collaborative 

opportunities to support upskilling 

and engineering development? 

The fundamental problem is, when 

building an innovative reactor there is 

no experience, no plan, so appropriate 

cost management is almost impossible 

because we don’t know all the steps, 

the required technologies, and the 

challenges (unknown unknowns). 

Introducing a structured process to 

the R&D will be a key requirement and 

will help to define a structured 

approach to the first of a kind (FOAK) 

or the later serial build. Learning on a 

small real project and going in steps 

will allow us to achieve a more 

efficient cost reduction than just 

learning from experience which typically 

takes place at a very later stage of 

the project which leads to delays and 

cost over runs. These multiple arguments 

speak for starting a new, innovative 

reactor programme on a small 

scale using a zero-power reactor to 

reduce the risk of the whole development 

program. 

Why do we need this program? 

The last indigenous reactor in the UK 

was constructed 1980 and put into 

operation in 1988, while the design 


A Zero-power Facility as a Multi-fold Opportunity to Support Quick Progress in Innovative Reactor Development ı Bruno Merk, Dzianis Litskevich, Anna Detkina, Greg Cartland-Glover, Seddon Atknison and Mark Bankhead


RESEARCH AND INNOVATION 60 

The Dungeness disaster 

Construction on the new AGR at Dungeness B started in 

January 1966. A later historian of the privatization of the 

British electricity industry described it as “the single most 

disastrous engineering project undertaken in Britain” 

[Henney (1994) p. 131]. Among a certain generation of 

people, Dungeness B is still a byword for failure of 

construction, design and project management on a heroic 

scale. The project was beset by delays, strikes and cost 

overruns. 

Henney, A (1994). A Study of the Privatisation of the Electricity 

Supply Industry in England & Wales, 

London: Energy Economic Engineering 

| Figure 1 

Simon Taylor (2016) The Fall and Rise of Nuclear Power in Britain: 

A history [8]. 

also occurred several decades earlier 

and the knowledge was not passed 

onto the next generation. This has led 

to a significant reduction in the 

number of the specialists in the 

nuclear sector. Looking deeper, the 

last indigenous development of a 

reactor has been delivered in the late 

1960ies, see Figure 1. This development 

was pushed by an ambitious 

construction programme aiming to 

deliver five twin reactor stations and 

was quickly rolled out to support 

business since export orders were 

eagerly anticipated. Thus, the situation 

seems to be a bit like the todays 

nuclear renaissance supported by 

the BEIS (Department for Business, 

Energy & Industrial Strategy) nuclear 

innovation program (NIP) [7] with 

the aim to produce business opportunities 

for UK plc and to become a top 

table nation in nuclear latest in 2050 

to support the green recovery. 

The lead station of the AGR program 

was Dungeness B which could 

be seen as industrial demonstrator 

and a first of a kind and it was a direct 

step into a large station without real 

stepwise development. It was ordered 

in 1965 with a targeted completion 

date of 1970. The project did not 

progress as expected, being several 

times delayed after problems in many 

aspects of the reactor design, a bit 

comparable to today’s mega projects, 

see Figure 1. Finally, electricity generation 

began in 1983, 13 years late, 

while full power was reached for the 

first time in 2004, roughly 38 years 

after construction began [8]. Another, 

early example how costly and time 

consuming it can be to learn on a full 

power project. The last, more successful, 

reactor of the AGR fleet was connected 

to the grid in 1989, thus the 

last classical UK thermal reactor project 

finished construction more than 

30 years ago. The last delivery in the 

innovative reactor program was the 

prototype fast reactor (PFR) which 

was announced in 1966 to be built at 

Dounreay. The PFR achieved first 

criticality in 1974 and grid connection 

1975. 

Thus, the design of the reactor 

system of the commercial fleet took 

place in the early 1960ies and the 

design of the innovative reactor 

system just shortly after, leading to 

the situation that the last experience 

of construction, commissioning, and 

connection to the grid took place in 

the late 1980ies [3]. This is a UK view, 

but only the dates will be slightly 

different in other western countries, 

while the introduction just shows that 

the situation is comparable. Maybe 

the length of time period will be 

slightly smaller, but in all cases, it is 

too far back in time to rely on the 

experience gained at that time. 

The key questions to answer are: 

p What should we learn from this 

history to avoid repetition of such a 

very costly disasters – costly in 

regards not only to money, but also 

with regards to time? 

p How can we re-gain experience 

and quick response in the whole 

process? 

p How can we reduce the risk in the 

project as mentioned at the end of 

the introduction? 

A key point will be to learn and to 

re- educate experts for the nuclear 

renaissance since the historic expertise 

is obviously lost. In addition, we 

can neither afford massive delays 

which are predictable and costly when 

problems appear at the very late stage 

of a project, e.g. in the middle of 

construction, nor do we have time to 

waste if nuclear should make a 

real contribution to a future net-zero 

society. Luckily, the situation still 

allows us to deliver on these tasks if 

we start now and if we use time and 

resources wisely. Moreover, in comparison 

with the 1960ies we have 

more robust and efficient simulation 

tools which should speed up the R&D 

activities. Digitalisation will help the 

whole process via end to end support 

and by adopted working practices 

instead of simply sending more information 

to key stakeholders creating a 

decision-making bottleneck. To make 

this possible some tools require 

targeted validation for the innovative 

reactor designs to leverage their 

full potential and to reduce time of 

development and costs significantly. 

The learning has to be supported 

by creating a structured programme 

from feasibility through to construction, 

see Figure 2, in combination 

with following the recently proposed 

4 step process [6] consisting of preliminary 

studies, an experimental 

phase starting with the zero power 

reactor as the key steps towards 

feasibility. This will support the smallscale 

demonstrator providing information 

for the preliminary design 

with the first experience of nuclear 

power production in a new kind of 

reactor. However, in an innovative 

reactor development, FOAK is going 

all the way through this cycle in each 

step. We need to build a complete 

programme at sufficient detail encompassing 

all of the R&D and skills 

development required to effectively 

project manage the delivery of each 

step right-to-left (thus backwards) 

engaging all of the stakeholders at 

each level in the process. 

| Figure 2 

A structured program for the development of a nuclear reactor along the recommendations in a WNA white paper [9]. 




All mentioned points demonstrate 

that we need a new strategy to speed 

up learning by identifying strengths 

and weaknesses of the capabilities 

and the current capacities available to 

be able to deliver the end-to-end 

approach developed above. Key will 

be to work on the known unknowns 

and to identify early the unknown 

unknowns – areas where the community 

is weak, but where we are not 

aware of the weakness or the lack of 

knowledge. Testing procedures and 

technologies early and on smaller 

scale will be of high importance to 

avoid costly late failures. 

Opportunities of a zero- power 

reactor as a first step 

Developing and delivering an indigenous 

zero-power facility should be the 

most promising first step into any 

innovative reactor program as a part 

of an active risk limitation program 

for the whole nuclear reactor development. 

The zero-power facility has the 

potential to be used as a multi-fold 

opportunity, since it is more than a 

system that can be used for the validation 

of numerical models and their 

inherent approximations. It is a FOAK 

and the opportunity to go through the 

whole process from design to operation 

of an innovative reactor facility 

testing the feasibility, but in contrast 

to any larger reactor it is delivering a: 

p low cost opportunity compared to 

a power reactor due to limited size 

and significantly reduced system 

complexity 

p low risk opportunity in time, 

finance, and nuclear – it is not 

rocket science, GUINEVERE [15] 

has finally been successfully 

delivered – here the reduced complexity 

is key, it reduces the number 

of critical tasks and the required 

safety systems. However, all key 

components for the nuclear island 

and the fuel production have to be 

designed, regulated, and delivered 

p less complex project, no heat transfer 

and no power conversion 

system are needed, no extensive 

multi-redundant and diverse safety 

systems are required as well as no 

expensive mitigation devices like a 

containment 

p quick response opportunity, since 

such a project should not take 

more than 3 to 5 years, a quick 

turnaround and an accelerated 

learning curve will be seen. 

Knowledge and capacity gaps will 

be identified in short time creating 

less costly opportunities to close 

gaps and even change/adapt the 

final pro duct in a comparably late 

project phase. 

p High flexibility of the facility itself 

which could be equipped with 

a new core (as done in the 

GUINEVERE project) if another 

technology should be investigated 

A zero-power facility for a new technology 

is a comparably small project, 

which still requires the whole production 

chain for a nuclear reactor, while 

it requests collaboration in an interdisciplinary 

team. Thus, it will be a 

perfect test case for the readiness for 

future, larger projects, assuring an 

accelerated learning curve in an innovative 

reactor technology on: 

p designing, 

p licensing, 

p constructing, 

p commissioning, and 

p operation 

Where can these advantages 

be delivered? 

As previously mentioned, the zeropower 

facility is a low cost, low risk, 

quick response project which delivers 

opportunities on different levels, see 

Figure 3. 

The opportunities of the facility are 

in detail: 

p Manufacturing 

Manufacturing an innovative 

reactor of a new technology will 

help identifying weak points 

( unknown unknowns), upskilling 

demands, and already available 

pockets of expertise. It will allow 

developing and testing of new technological 

approaches and advanced 

manufacturing techno logies on a 

small scale and support the creation 

of a core team of experts with 

real hands on experience for the 

following small scale demonstrator 

which would make the UK an 

| Figure 3 

The multiple opportunities which can be delivered in a zero-power facility. 

attractive location to deploy these 

designs. Testing of new components, 

e. g. establishing a pre-industrial 

fuel production. It will help 

creating and educating the required 

supply chain for the technologies. 

All points will be essential for progressing 

into the next step of the 

development process – the smallscale 

demonstrator. 

p Experiment 

On the one hand, the experiment 

will help in the education and 

the qualification of future reactor 

physics experts, which are highly 

demanded worldwide. On the other 

hand, it will help to improve the 

recognition of reactor physics and 

new reactor technologies. Thus, it 

will attract bright students of future 

generations into nuclear. The 

investment in an experiment will 

showcase the innovation potential 

in nuclear technologies and the 

drive to innovate to the public. 

p Leading Science 

Taking the lead through an investment 

into advanced reactor technologies 

such as the proposed 

molten salt reactor technology. 

The investment into the zeropower 

facility will create a sustainable 

long term claim in an innovative 

reactor technology. The facility 

will create the opportunity to provide 

safety demonstrations and 

code validation and deliver an 

accelerated learning curve for the 

operating entity as well as the local 

academic community. The demonstration 

opportunity will help 

creating new IP for the country. 

The facility will attract top scientists 

to the country either in collaborations 

or through relocation 

while giving UK plc an advantageous 

position. 






An already successful example: 

p Business Opportunity 

Finally, besides the leading science, 

the facility will allow experiments 

for international partners and for 

industrial developers who cannot 

afford to build their own zeropower 

system, as has been 

delivered for decades through 

the BFS at IPPE Obninsk for international 

sodium fast reactor 

development or through the new 

opportunities of GUINEVERE at 

SCK∙CEN at Mol for lead cooled 

fast reactor technologies. The 

facility will serve industry to 

support the home-grown supply 

chain and link them to reactor 

developers while earning money 

through paid experiments. 

How can these advantages be 

delivered? 

The key for the success will be to make 

the most out of the money invested, as 

well as to use the time available 

wisely. The zero-power reactor project 

has to deliver much more than only 

results for code validation or safety 

demonstration, which would be the 

outcome of doing paid experiments at 

another facility. Possible opportunities 

are given above. 

A zero-power reactor project can 

build on these first approaches 

delivered in project FAITH (see text 

box), but it can and has to go much 

further. The accelerated learning curve 

starts already with the design and 

manufacturing of a facility to study 

innovative reactor development and 

operation, not with the experiment. 

Creating, enabling, and edu cating the 

supply chain on a very small scale and 

reduced complexity system, as a basis 

for the next level of the small-scale 

A first demonstrator of this approach is Project FAITH (Fuel 

Assembly Incorporating Thermal Hydraulics) a multi- purpose 

project using new, highly innovative approaches to make 

better use out of the invested money. Main side purposes are: 

Educating new partners from outside of the nuclear industry 

how to deliver on nuclear standards while using already 

established innovations from other technologies, e. g. modular 

manufacturing established in ship building or application of 

tailored materials through additive manufacturing. “In FAITH 

we intend to demonstrate modular manufacturing on small 

scale with low cost and complexity to quickly evaluate a key 

technology for small modular reactors, while creating an 

opportunity for qualification and education of the strongly 

demanded workforce. This is delivered by a stepwise approach 

from easy to build and operate experiments into future 

cuttingedge science and technology with a complex and 

challenging fluid. All surrounded by digital design and 

development technologies from cradle to grave as well as the 

approach to deliver a project management integrated with the 

technical delivery. This will allow to include product quality 

management into the digital twin as well as thinking in terms 

of the whole project lifecycle using a common modelling 

environment.” [9] 

power demonstrator. Key points will be 

to develop and test new approaches 

(modular manufacturing, advanced 

fuel production, and applying digital 

twin technology across the whole lifecycle 

of the asset), accept failure and 

be prepared for a quick for recovery to 

support rapid developments, but in 

all cases by using small steps. This 

approach reduces risk and promotes 

learning and solving problems at each 

step. Learning has to be seen as a process 

making progress based on UK 

capabilities and capacities instead of 

just buying a product. It is about 

involving all main suppliers into the 

development instead of having just 

suppliers delivering their parts. This 

also implies using the available nuclear 

chemistry expertise of academic partners 

to improve the available database 

for the pre- experiments required for 

the design, as well as upgrading of 

existing facilities to be able to deliver 

on the new challenges, e.g. salt based 

uranium fuels production. A further 

opportunity is refurbishing existing 

facilities and retaining the highly 

skilled employees at these facilities 

thus serving as a social-economic development 

to support a new facility as 

in the case of the VENUS facility at 

SCK. This will be complemented by 

linking with leading groups from outside 

nuclear energy to involve them in 

the project and attract available expertise 

from other areas, e. g. detector 

development for particle physics delive 

ring UK’s contribution to CERN experiments 

or modular manufacturing. 

It is about using the experiment 

to deliver a hands on education to give 

the future experts a tier-one experience 

in building a new type of reactor as well 

as to operate the facility instead of 

completely relying on modelling & simulation 

as it has often become tradition 

in reactor physics. The facility will offer 

very effective accelerated learning to 

the next generation of engineers and 

scientists that comes with de signing, 

developing and constructing the facility 

as well as running and ana lyzing the 

experiments. The facility will be at the 

centre of a user community and 

attracting international experts while 

growing an experimental program for 

a new type of zero- power experiment 

in collaboration with national and 

international partners. In addition, the 

facility will allow the testing of new 

detector technologies in a challenging 

environment and potentially invest 

into developing some tailored, innovative 

detector technology. 

The development of zero-power 

experiments will proceed from easy 

to complex to support the learning 

process, a further example of learning 

from project FAITH. Most probably, the 

experimental campaign will be started 

with experiments based on a solid salt 

block operating at room temperature 

to learn how to apply experimental

atw - International Journal for Nuclear Power | 03.2021

You also want an ePaper? Increase the reach of your titles