atw - International Journal for Nuclear Power | 05.2021
Description Ever since its first issue in 1956, the atw – International Journal for Nuclear Power has been a publisher of specialist articles, background reports, interviews and news about developments and trends from all important sectors of nuclear energy, nuclear technology and the energy industry. Internationally current and competent, the professional journal atw is a valuable source of information. www.nucmag.com
Description
Ever since its first issue in 1956, the atw – International Journal for Nuclear Power has been a publisher of specialist articles, background reports, interviews and news about developments and trends from all important sectors of nuclear energy, nuclear technology and the energy industry. Internationally current and competent, the professional journal atw is a valuable source of information.
www.nucmag.com
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
nucmag.com
2021
5
ISSN · 1431-5254
32.50 €
Is Wind
the Next Nuclear?
Operating Experience from
Ageing Events Occurred
at Nuclear Power Plants
Kazatomprom and
the Nuclear Fuel Cycle
TIMES ARE CHANGING
Important notice for international subscribers!
The nuclear phase out in Germany not only concerns the nuclear industry itself but literally
all accompanying national players such as the specialized press.
Therefore, also atw – International Journal for Nuclear Power must shift its focus and will emphasize
the national context much more than in previous years. One focus will be on the German nuclear
decommissioning market and consistently many articles published will be primarily in German
language.
Despite the fact that much of the journal will be in German, starting January 2022, we plan
to publish some English articles in every issue. Furthermore, the size of the magazine will be
reduced according to the shrinking importance of the national German nuclear market.
As a consequence of all the changes announced above, our international customers have
a special right of immediate and easy termination of subscription which is effective on
January 1 st , 2022.
Nevertheless, to maintain our strong claim to foster nuclear competence a new online platform
‘atw scientific’ will be introduced in November 2021. Completely in English language, ‘atw scientific’
will be an open-source web platform for worldwide scientific nuclear content, where submissions
will be pre-reviewed and DOIs will be assigned. More information will be available soon!
We would like to take this opportunity to warmly thank you – especially
our gentle international readers – for staying with atw and we hope to
meet you at the new international online platform ‘atw scientific’!
atw Vol. 66 (2021) | Issue 5 ı September
Uranium Supply – Sustainable
3
Dear Reader, In environmental and economic policy, the term “sustainability” has a high status; it is a popular
springboard for ideas or visions for goals of any kind. The origin of the term “sustainability” can be traced back to the
Brundtland Commission, also called the World Commission on Environment and Development. In 1987, it published the
report “Our Common Future”, in which the concept of sustainable development was formulated and defined for the first
time, thus providing the impetus for a worldwide preoccupation with and public attention to the topic of sustainability.
Following its origins, the term 'sustainable' defines development “that meets the needs of the present without
compromising the ability of future generations to meet their own needs and choose their own lifestyles.”
In this sense, what could be more sustainable than
nuclear energy?
Keyword resource conservation: Nuclear power
plants under construction and commissioning today
will, by design, achieve technical lifetimes of 60 years
and more from the outset. For nuclear power plants in
operation today, lifetimes of 60 years are now a matter
of course, 80 years are partly under review and
100 years are under consideration.
Keyword resource availability: Both in terms of
sustainability and in terms of an investment in a nuclear
power plant that can be operated for up to 100 years,
the question of the availability of nuclear fuel arises, i.e.
with today’s nuclear fuel input, the question of uranium
resources.
Since the mid-1960s, the “Red Book” – Uranium:
Resources, Production and Demand* – by the Nuclear
Energy Agency (NEA) of the Organisation for Economic
Development (OECD) and the International Atomic
Energy Agency (IAEA) has provided an answer to this
question, which is periodically discussed here. The Red
Book provides a detailed and reliable insight into the
current situation of the entire uranium and nuclear fuel
supply. In addition, the Red Book provides an outlook
on the demand and supply forecast for the coming
decades. The data in the 28 th edition, which has now
been published, has been compiled with the support of
37 member states of both organisations and analyses by
the experts of NEA and IAEA. In addition, other aspects
of nuclear fuel supply are outlined, such as environmental
protection and price development.
On the uranium supply side, the Red Book identifies
a small but renewed and thus steady increase in
resources compared to 2017: according to the tiered list
classified by cost, a total of 8.070 million tonnes of
uranium at extraction costs < US$ 260/kgU (or < US$
100/lbU) are reported as reserves on the cut-off date of
January 1, 2019. This is 0.1 % more than two years
earlier. In the previous report, the same increase was
recorded. The main cause is seen in the changed market
situation with lower revenues on the uranium extraction
side, which is reflected in lower efforts in the search
and exploration of new uranium deposits. Natural
uranium is available in sufficient quantities for nuclear
power plant needs, in the short and medium term as
well as in the long term, which has created significant
price pressure that has caused the uranium price to fall
from its last high in 2007 of around US$ 130/lb U 3 O 8 to
the current level of around US$ 30/lb U 3 O 8 ; in the
meantime, in 2016, a low of just under US$ 20/lb was
recorded. This is associated with lower global uranium
exploration activities and consequently lower reserve
growth – although more new uranium sources were
found than uranium mined for energy production in
the same period. The current Red Book shows that
China, India, Canada, Kazakhstan and the USA were
leading in the uranium extraction sector, i.e. exploration
and establishment of mines, in the period from 2016 to
2018. The investments made in Canada alone were
higher than those of the next five countries in total.
Expenditures totalled approximately US$ 1.8 billion.
Global uranium production in 2019 was 54,244 tU,
about 1 % higher than in the previous year 2018 but
about 16 % lower than in 2016. 92 % of the uranium
demand of about 59,200 t in 2019 was thus covered by
current production and 8 % by so-called secondary
sources, i.e. the return of uranium from reprocessing or
former military material and stockpile withdrawals.
With regard to medium-term security of supply and
the extent of future uranium production, the authors of
the Red Book point to a balanced constellation until
2040. The existing uranium mines, those currently
being developed and those planned, will foreseeably
cover the uranium demand even in the scenario of
a high increase in nuclear energy from currently
396,000 MW worldwide to 626,000 MW in 2040.
Today’s reserves of 8,070 million tonnes of uranium
are sufficient to cover the current nuclear fuel demand
for 135 years. In addition, resources are shown to be in
the order of another 15 million tonnes of uranium. On
the nuclear fuel supply side, there is thus neither a
supply shortage nor an acute need for action.
In addition, the innovation potential of nuclear
technology offers further perspectives; on the uranium
extraction side, for example, the tapping of the uranium
reservoir in the world’s oceans, which is quasi-infinite
according to current estimates, up to advanced fuel
cycles or new nuclear fuels such as thorium, which
would expand today’s resources by a factor of 100 and
more.
Uranium supply is therefore a sustainable factor of
nuclear energy, which also offers future generations
sufficient potential for utilisation and even the urgently
needed expansion of power generation capacities.
Christopher Weßelmann
– Editor in Chief –
*) Uranium 2020:
Resources, Production
and Demand, A Joint
Report by the OECD
Nuclear Energy
Agency and the
International Atomic
Energy Agency, NEA
No. 7551, Paris, 2020
EDITORIAL
Editorial
Uranium Supply – Sustainable
atw Vol. 66 (2021) | Issue 5 ı September
4
CONTENTS
Issue 5
2021
September
Contents
Editorial
Uranium Supply – Sustainable. . . . . . . . . . . . . . . . . . . . . . . . 3
Inside Nuclear with NucNet
Why Moscow Is Banking on Small Reactors to Power Economic
Development in Remote Regions . . . . . . . . . . . . . . . . . . . . . .6
Mattia Baldoni
Did you know? 7
Cover:
Verifying the diameter of uranium fuel pellets
produced at the Ulba Metallurgical Plant
(Courtesy of NAC Kazatomprom JSC).
Calendar 8
Feature | Research and Innovation
Is Wind the Next Nuclear? . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Schalk Cloete
Interview with Yves Desbazeille
“Since the Beginning, FORATOM Has Advocated for the
Taxonomy to Follow a Technology Neutral Approach.” . . . . . . . 14
Operation and New Build
Operating Experience from Ageing Events Occurred
at Nuclear Power Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Antonio Ballesteros Avila and Miguel Peinador Veira
At a Glance
Ultra Safe Nuclear Corporation . . . . . . . . . . . . . . . . . . . . . . . 24
Fuel
Westinghouse Fuel Design Advancements . . . . . . . . . . . . . . . 26
Derek Wenzel, Uffe Bergmann and Juan Casal
Kazatomprom and the Nuclear Fuel Cycle . . . . . . . . . . . . . . . . 30
Mazhit Sharipov
Site Spotlight
Nuclear Expertise for Germany – Indispensable
Even After the German Nuclear Phase-out . . . . . . . . . . . . . . . 34
Nuclear Competencies in Germany – a Legitimate Case
Also After the Nuclear Phase-out . . . . . . . . . . . . . . . . . . . . . 38
Decommissioning and Waste Management
SSiC Nuclear Waste Canisters: Stability Considerations
During Static and Dynamic Impact . . . . . . . . . . . . . . . . . . . . 42
Yanan Zhao, Heinz Konietzky, Juergen Knorr and Albert Kerber
Research and Innovation
Improving Henry-Fauske Critical Flow Model
in SPACE Code and Analysis of LOFT L9-3. . . . . . . . . . . . . . . . 50
BumSoo Youn
Non-destructive Radioactive Tracer Technique
in Evaluation of Photo- degraded Polystyrene Based
Nuclear Grade Ion Exchange Material . . . . . . . . . . . . . . . . . . 54
Pravin U. Singare
News 62
Nuclear Today
As Science Turns Up the Heat on Climate Change Sceptics,
How Long Before the Nero-like Nuclear Deniers
Must Change Their Tune? . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Imprint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Contents
atw Vol. 66 (2021) | Issue 5 ı September
5
Feature
Research and Innovation
CONTENTS
9 Is Wind the Next Nuclear?
Schalk Cloete
Interview with Yves Desbazeille
14 “Since the Beginning, FORATOM has Advocated
for the Taxonomy to Follow a Technology Neutral Approach.”
Operation and New Build
18 Operating Experience from Ageing Events Occurred
at Nuclear Power Plants
Antonio Ballesteros Avila and Miguel Peinador Veira
Fuel
26 Westinghouse Fuel Design Advancements
Derek Wenzel, Uffe Bergmann and Juan Casal
30 Kazatomprom and the Nuclear Fuel Cycle
Mazhit Sharipov
Site Spotlight
34 Nuclear Expertise for Germany – Indispensable Even After
38
the German Nuclear Phase-out
Nuclear Competencies in Germany – a Legitimate Case Also After
the Nuclear Phase-out
Contents
atw Vol. 66 (2021) | Issue 5 ı September
6
Why Moscow is Banking on Small Reactors
to Power Economic Development in Remote Regions
Mattia Baldoni
INSIDE NUCLEAR WITH NUCNET
Russia says it faces inevitable challenges with plans to build its first land-based small modular
reactor because of poor transport infrastructure in the eastern public of Yakutia, but is confident
the project will go ahead and that the country has a big enough domestic market for serial SMR
production – which could begin as soon as 2030.
State nuclear corporation Rosatom confirmed reports late
last year that Russia is planning to build a land-based SMR
in Yakutia, also known as Sakha, an autonomous republic
4,000 km to the east of Moscow, between Siberia and
Russia’s far east. Rosatom said it is aiming to commission
the unit by 2028.
Foremost among hurdles are the remote location and
poor transport infrastructure because of permafrost.
Rosatom, however, remains confident that construction
will go ahead as scheduled and says progress is being made.
A field survey has been completed at a potential site in
Ust-Kuyga, a settlement on the Yana River with a population
of less than 1,000. Rusatom Overseas, Rosatom’s foreign
business division, is planning to draw up a declaration of
intent for Yakutia to invest in the project.
Rosatom said it could not give cost estimates because the
final price will depend on factors such as location, safety
requirements and local regulatory standards. “The exact
cost for each specific customer may be determined by the
results of a detailed feasibility study, taking into account
particular specifications of the project,” the company said.
“What we can say is that final electricity prices will be
competitive compared to other sources of energy in those
locations after factoring in carbon fuel prices and infrastructure
costs, and even in comparison with other SMR
vendors.”
Rosatom believes it has a large enough domestic market
for serial SMR production. Serial production, together with
the development of government-private partnerships, is
crucial if SMRs are going to be economically viable. The
Nuclear Energy Agency said recently that SMRs could become
commercially viable by the early 2030s, but efforts to build
the first plants would benefit from international collaboration
and more government support.
If SMRs are manufactured in a mass production fashion,
similar to commercial aircraft, the economic benefits could
be significant, the NEA said. But this would require that
the market for a single design be relatively large and raises
the possibility that only a small number of the many
designs under development will ultimately succeed.
In the UK, a consortium led by Rolls-Royce said an SMR
it is developing will initially cost about £2.2bn per unit,
dropping to £1.8bn by the time five have been completed.
This means it will be comparable with offshore wind at
around £50/MWh.
Russia’s energy strategy to 2035 (Russian only) stresses
the role nuclear can play in energy security and the drive
for zero emissions. It says there is a need for low-power
nuclear plants for remote regions, but says nuclear’s
economic competitiveness needs to increase.
One of Moscow’s major considerations as it seeks to
modernise its energy infrastructure and provide affordable
electricity is how to provide power for remote areas like the
Arctic. SMRs represent a promising source of energy for
areas away from central power grids. “With the help of
SMRs, the Arctic can achieve net-zero emissions as early as
2040,” said Anton Moskvin, vice-president for marketing
and business development at Rusatom Overseas.
The NEA said the most optimistic deployment scenarios
assume successful licensing and the establishment of the
factory production and associated supply chain that would
lead to cost competitiveness. In a more conservative
low-deployment scenario, SMRs would be considered
expensive to build and operate, and thus only a limited
number of projects would be completed.
Traditional energy sources such as coal and gas are
falling out of favour as countries join the fight against
climate change. They are also unable to satisfy growing
demand for heat and electricity in remote area areas. Coal
and oil, for example, need to be moved to the site along
with all their ancillary services. The simplicity of SMRs
means they could be taken to a rural location by road or
sea and operate with minimal intervention for 60 years or
more. Rosatom wants the Yakutia SMR to be a clean source
of heat and electricity both for mining facilities and for
local residents, replacing carbon-intensive coal-fired and
diesel facilities. It says the plant will contribute to the
reduction of up to 10,000 tonnes of CO 2 per year.
The proposed Yakutia SMR is based on Russia’s
RITM-200, an advanced pressurised water reactor unit
which is already operational on new-generation icebreakers.
Russia has also led the way in the SMR sector with its
first-of-a-kind floating nuclear power plant Akademik
Lomonosov, which has two KLT-40S reactors and is the
world’s first advanced SMR. It was connected to the grid in
December 2019 in Pevek, Chukotka Peninsula. In May
2020 it began full commercial operation, generating
electricity for households and local industries in Russia’s
east Arctic region.
According to the NEA, Rosatom is planning more
floating SMRs at the Baltic Shipyard in St. Petersburg. In
parallel, it has been developing the RITM-200 for both
floating and land-based deployment. Serial construction
could start by 2030, with the first units to be installed at
Russia’s biggest mine sites.
Possible candidate sites for SMRs are the Suroyam iron
ore deposit near Chelyabinsk in southwest Russia, the
Baim minerals deposit in Chukotka, in Russia’s far east,
and other sites in Yakutia. Reports earlier this month in
Russia said president Vladimir Putin has approved a
Rosatom proposal to power the Baim mining venture by
building as many as five floating nuclear power plants.
Rosatom also says interest in Russian-designed floating
nuclear power plants is growing in Latin America, Asia,
and Africa – all areas where electricity is needed in remote
locations and a problem for which Russia thinks it is
getting close to a solution.
The race to develop and manufacture SMRs is intense,
with at least 72 reactor concepts under various stages of
development in countries as diverse as Argentina, Canada,
the US, the UK, China, Japan, South Korea and France. The
question of the market remains central, says the NEA, but
Inside Nuclear with NucNet
Why Moscow is Banking on Small Reactors to Power Economic Development in Remote Regions
atw Vol. 66 (2021) | Issue 5 ı September
with its state-backed corporations and access to federal
funding, this is one area where Russia might have an
advantage over rivals in countries where governments are
reluctant to intervene in the market.
“It is a ‘chicken and egg’ situation,” said Frederik Reitsma,
team leader for SMR technology at the International Atomic
Energy Agency. “On the one hand, investment to develop
and deploy SMRs requires a secured market and demand for
the product, but on the other, one cannot secure the market
without funding to develop and demonstrate, or even to do
the necessary research or build test facilities that may be
required for licensing. Potential investors are hesitant to
invest in new technology if they are unsure about the market
risks.”
Author
Mattia Baldoni
NucNet – The Independent Global Nuclear News Agency
www.nucnet.org
DID YOU EDITORIAL KNOW?
7
Did you know?
Electricity Price Hike in Summer 2021
The Institute of Energy Economics at the University of Cologne
(EWI) published an analysis of the electricity price hike observable
in the first half of 2021 on the German wholesale market for
electricity under the German title “Anstieg der Strompreise
im Sommer 2021”. Similar developments take place in other
European markets too. The analysis uses the EWI-Merit-Order-
Tool and concludes that the major drivers of increasing electricity
prices are high fuel prices and a high price for CO 2 -allowances in
the EU Emission Trade System (ETS). Gas prices reached their
highest level for over 10 years in the first week of July 2021 with
36 Euro/MWh and coal reached its highest price level since 2011
with 15 Euro/MWh. At the same time the price for an ETS
certificate for the emission of one tonne of CO 2 rose from 33 Euro/
tonne in January 2021 to over 57 Euro at the end of June receding
a little thereafter.
This input price development caused a significant effect on the
marginal cost of gas and coal power plants which increased
significantly not only compared to covid-crippled 2020 but also
compared to 2019. In combination with higher demand in 2021
compared to 2020 (the electricity demand increased by 5 per cent
in the first half of 2021 compared to 2020) and a shortened merit
order as consequence of power plants closing down in the the
first steps of the German coal phase-out, a market environment
was created that exerted intensive upward pressure on wholesale
electricity prices. While a reduced production of renewable
power, particularly wind, also contributed to market pressure, the
analysis indicates that the so called residual demand remained
within the bounds of what has been observed during the past
years and was not a significant factor for rising prices.
Looking beyond the analysis on Germany one finds a high
electricity price level in the UK too. In January 2021 the monthly
average price for day ahead baseload contracts rose above
90 Pound/MWh, within striking distance of the severly critized
strike price of 92.50 Pound/MWh for the Hinkley Point C (HPC)
nuclear power plant under construction and even higher than the
initial strike prices for Hinkley Point C and Sizewell C (SZC) in case
the Sizewell project is realised which are 89.50 Pound/MWh for
HPC and 86.50 Pound/MWh for SZC. It has to be said though, that
the inflation adjusted current strike prices are higher than the
initial ones.
Prices for Electricity and Gas
in Euro/MWh for CO 2 in Euro/tonne
Wholesale Electricity
Price 2019
Wholesale Electricity
Price 2020
Wholesale Electricity
Price 1 st half of July 2021
Wholesale Gas
Price July 2021
CO 2 -Price
(per tonne)
31
36
38
55
Source:
Anstieg der Strompreise
im Sommer – Wie
Brennstoff- und
Zertifikatepreise sowie
die Residualnachfrage
auf Großhandelsstrompreise
wirken. Eine
Analyse mit dem EWI
Merit-Order-Tool; Çam,
Arnold, Gruber; Energiewirtschaftliches
Institut
an der Universität zu
Köln (EWI); Juli 2021
86
| Wholesale Electricity Prices Germany August 2020 to July 2021; www.smard.de.
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?
atw Vol. 66 (2021) | Issue 5 ı September
8
Calendar
CALENDAR
2021
04.10. – 05.10.2021
AtomExpo 2021. Sochi, Russia, Rosatom,
http://2021.atomexpo.ru/en
Online Conference 04.10. – 06.10.2021
ICEM 2021 – International Conference on
Environmental Remediation and Radioactive
Waste Management. ANS,
https://www.asme.org
12.10. – 13.10.2021
TotalDECOM 2021. TotalDECOM, Manchester,
UK, www.totaldecom.com
13.10. – 14.10.2021
NuFor 2021: Nuclear Forensics Conference.
IOP Institute of Physics, London, UK,
www.nufor.iopconfs.org
Hybrid Conference 16.10. – 20.10.2021
ICAPP 2021 – International Conference on
Advances in Nuclear Power Plants. Khalifa
University, Abu Dhabi, United Arab Emirates,
www.icapp2021.org
19.10. – 21.10.2021
ICOND 2021 – 10 th International Conference
on Nuclear Decommissioning. AiNT, Aachen,
Germany, www.icond.de
Postponed to 24.10. – 28.10.2021
TopFuel 2021. Santander, Spain, ENS,
https://www.euronuclear.org/topfuel2021
15.11. – 17.11.2021
NESTet2021 – Nuclear Education and Training.
ENS, Brussels, Belgium, www.ens.eventsair.com
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
2022
26.01. – 28.01.2022
PowerGen International. Clarion Events, Dallas,
TX, USA, www.powergen.com
06.03. – 11.03.2022
NURETH19 – 19 th International Topical Meeting
on Nuclear Reactor Thermal Hydraulics.
SCK·CEN, Brussels, Belgium,
https://www.ans.org/meetings/view-334/
05.04. – 07.04.2022
GLOBAL 2022 – International Conference
on Nuclear Fuel Cycle. Sfen, Reims, France,
www.new.sfen.org
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
04.05. – 06.05.2022
NUWCEM 2022 – 4 th International Symposium
on Cement-Based Materials for Nuclear
Wastes. Sfen, Avignon, France,
https://new.sfen.org/evenement/nuwcem-2022
15.05. – 20.05.2022
PHYSOR 2022 – International Conference
on Physics of Reactors 2022. ANS, Pittsburgh,
PA, USA, www.ans.org
22.05. – 25.05.2022
NURER 2022 – 7 th International Conference
on Nuclear and Renewable Energy Resources.
ANS, Ankara, Turkey, www.ans.org
Postponed to 30.05. – 03.06.2022
20 th WCNDT – World Conference
on Non-Destructive Testing. Incheon, Korea,
The Korean Society of Nondestructive Testing,
www.wcndt2020.com
26.10. – 28.10.2021
VGB Conference Chemistry. Ulm, Germany,
VGB PowerTech, www.vgb.org
31.10. – 12.11.2021
COP26 – UN Climate Change Conference.
Glascow, Scotland, www.ukcop26.org
Postponed to 07.11. – 12.11.2021
PSA 2021 – International Topical Meeting on
Probabilistic Safety Assessment and Analysis.
ANS, Columbus, OH, USA,
http://psa.ans.org/2021
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
10.07. – 15.07.2022
SMiRT 26 – 26 th International Conference on
Structural Mechanics in Reactor Technology.
German Society for Non-Destructive Testing,
Berlin/Potsdam, Germany, www.smirt26.com
04.09. – 09.09.2022
NUTHOS-13 – 13 th International Topical Meeting
on Nuclear Reactor Thermal Hydraulics,
Operation and Safety. ANS, Taichung, Taiwan,
www.ans.org
This is not a full list and may be subject to change.
Calendar
atw Vol. 66 (2021) | Issue 5 ı September
Is Wind the Next Nuclear?
What the nuclear stagnation tells us about the challenges
that lie ahead for renewable energy
Schalk Cloete
Introduction Levelized costs of electricity often dominate the energy and climate debate. Green advocates like to
believe that if we only invest enough in wind and solar, the resulting cost reductions will soon put an end to fossil fuels.
While this is already a strongly oversimplified viewpoint, a narrow focus on cost makes such simplistic analyses even
less helpful.
This article will elaborate by example of two clean energy
technologies that face very different non-economic
barriers: nuclear and wind.
The Nuclear Stagnation
When technology is new and exciting, people only see the
positives. It is only when we reach market shares where
people start experiencing negative impacts that opinions
turn negative.
In the case of nuclear, the global expansion was
handicapped by the Chernobyl disaster in 1986, and the
nascent developing world expansion was interrupted by
Fukushima in 2011. As shown in Figure 1, Chernobyl
happened when nuclear reached about 5 % of the global
energy supply. Today, we are back down to 4.2 %.
Deaths from Chernobyl are estimated somewhere
between 4,000 and 60,000 1 , only 31 of which can be
attributed directly to the blast and high-level radiation
exposure. Fukushima had a much lower death toll at 574 2 ,
almost all due to evacuation stress. For perspective, it is
estimated that one future premature death results
from every 300 to 3000 tons of burnt carbon 3 or 1100 to
11,000 tons of CO 2 released into the atmosphere. Hence,
if we assume that the 93,000 TWh of nuclear power
generated to date displaced coal at 0.8 ton-CO 2 /MWh, the
74 billion tons of CO 2 avoided by nuclear has already saved
7–70 million lives, not counting the additional impact of
avoided air pollution.
There is much controversy around these estimates, but
they serve to illustrate that the public health benefits of
nuclear easily outweigh the costs. Clearly, the public
backlash against nuclear was not rational from a bigpicture
view. But that does not matter. The effects of public
resistance are real, whether it is rational or not.
A Wind Stagnation?
As Figure 1 shows, wind market share is currently
expanding at about half the speed of nuclear market share
in the seventies and eighties. Although wind does not face
risks from black swan events 4 like nuclear, it faces its own
brand of public resistance, both to the turbines themselves
and the extensive network expansions required to integrate
higher wind shares.
| Fig. 1.
Comparison of the global expansion of wind and nuclear from BP Statistical Review data. Both wind and
nuclear electricity output are multiplied by 2.5 to convert it to displaced primary fossil energy. Source:
https://www.bp.com/en/global/corporate/energy-economics/statistical-review-of-world-energy.html
As our societies become more advanced, we increasingly
demand an invisible energy system. Over here in Norway,
the usually reserved population is reacting furiously 5 to
onshore wind expansion plans. Turbines dotting the
pristine Norwegian landscape are unimaginable to this
wealthy society, the origin of its wealth 6 notwithstanding.
In Germany, resistance to turbines and grid expansions
has almost brought onshore wind expansion to a halt 7 at
current levels (about 7 % of total energy demand).
That is wind’s greatest challenge: It is the most visible
energy technology we have. As wind power continues to
expand and turbines grow ever larger, its visibility will only
grow while society’s tolerance for highly visible energy
technologies continues to decline. Advanced societies also
become increasingly concerned with nature preservation,
leading to additional hurdles related to bird protection 8 .
Offshore wind can help, but it will need to be built
far from shore to be sufficiently invisible, making it more
costly. It also faces further economic challenges from
wake effects that strongly reduce output 9 as total installed
capacity increases. In addition, offshore wind requires
large grid expansions to serve inland regions. Making
9
FEATURE | RESEARCH AND INNOVATION
1 https://ourworldindata.org/what-was-the-death-toll-from-chernobyl-and-fukushima
2 https://ourworldindata.org/what-was-the-death-toll-from-chernobyl-and-fukushima
3 https://www.frontiersin.org/articles/10.3389/fpsyg.2019.02323/full
4 https://en.wikipedia.org/wiki/Black_swan_theory
5 https://www.worldoil.com/news/2020/12/9/more-norwegians-saying-not-in-my-backyard-to-onshore-wind-farms
6 https://edition.cnn.com/2021/02/17/world/climate-hypocrites-uk-canada-norway-intl/index.html
7 https://www.dw.com/en/german-wind-energy-stalls-amid-public-resistance-and-regulatory-hurdles/a-50280676
8 https://www.cleanenergywire.org/news/german-environment-ministry-weighing-wind-farm-distance-regulations-protect-birds
9 https://www.agora-energiewende.de/en/publications/making-the-most-of-offshore-wind
Feature
Is Wind the Next Nuclear? ı Schalk Cloete
atw Vol. 66 (2021) | Issue 5 ı September
FEATURE | RESEARCH AND INNOVATION 10
these expansions invisible (underground cables) is very
expensive.
Solar is not immune either. Large solar farms can
ruin scenic vistas and damage natural habitats. Waste
from decommissioned plants could be another major
concern. 10
Furthermore, transmitting solar energy from
sunny regions to population centers (often poorly
correlated 11 ) will face similar resistance to wind network
expansions. Ultimately, any industrial-scale energy
technology has its drawbacks, and variable renewables
are no exception 12 .
Like nuclear, most of the resistance to renewables is not
rational from a big-picture viewpoint. Surely, seeing the
occasional wind turbine in the wild is worth the climate
benefits. But again, the rationality of this resistance does
not matter. What matters is the effect it has on clean
technology deployment.
The Undervalued Issue of System Complexity
Megaprojects that involve many interconnected technical,
economic, political, and social challenges are extremely
difficult to execute on time and within budget. Nuclear
offers a prime example with many stories of budgets
and timelines that were grossly exceeded, increasingly
stringent safety regulations being only one reason 13 .
In comparison, the modular construction and
installation of a wind turbine is child’s play. For decades,
the simple and standardized construction and installation
of wind and solar have been a big driver behind their
impressive growth and falling costs.
But this will not last. Higher wind market shares require
vast grid expansions (often into neighboring countries)
and lots of integration with other sectors that previously
operated independently (and need to be reinvented to run
on clean energy). In the longer term, this includes a large
hydrogen production, transport, storage, and end-use
sector that must be built from scratch. Executing this
enormous integrated project in a shifting policy- technology
landscape with impossibly tight climate timelines and
increasing public resistance can easily surpass the scale
and complexity of nuclear projects.
As the nuclear example shows, sub-optimal execution
should be expected in such a large, complex, and multifaceted
project, inflating overall system costs and slowing
the energy transition.
The remainder of this article will quantify these effects
using a modified version of a published energy systems
model 14 loosely based on Germany (further model details
are given in the Appendix).
Model Results
The coupled electricity-hydrogen system model is run for
three distinct scenarios, each varying the most relevant
model parameter:
p No CCS or Nuclear: In this renewables-dominated
scenario, the critical variable is the added costs from
integration challenges, public resistance, and high
system complexity. These costs are varied via cases that
double and triple the added electricity and hydrogen
grid costs needed to connect wind and solar generators
to demand centers.
p No CCS: This scenario allows nuclear but not CO 2
capture and storage (CCS). The critical variable in this
scenario is the cost of constructing nuclear power
plants, varied between 4000 and 8000 €/kW.
p All Technologies: CCS is allowed to decarbonize
natural gas-fired power and hydrogen production. The
natural gas export price is the critical variable in this
| Fig. 2.
Optimal electricity generation and consumption in the different cases. CCS = Natural gas power production with CO 2 capture and storage; Natural gas = Unabated
natural gas power production; Others = Efficiency losses from batteries and electricity consumption involved in hydrogen storage.
10 https://hbr.org/2021/06/the-dark-side-of-solar-power
11 https://energycentral.com/c/ec/what-potential-distributed-generation
12 https://www.brookings.edu/wp-content/uploads/2020/01/FP_20200113_renewables_land_use_local_opposition_gross.pdf
13 https://arstechnica.com/science/2020/11/why-are-nuclear-plants-so-expensive-safetys-only-part-of-the-story/
14 https://www.sciencedirect.com/science/article/pii/S0360319920336673?via%3Dihub
Feature
Is Wind the Next Nuclear? ı Schalk Cloete
atw Vol. 66 (2021) | Issue 5 ı September
scenario and is varied between 4 and 8 €/GJ (natural
gas transmission costs are added separately).
In addition, a Mix case is added where a balanced mix of
renewables, nuclear, and natural gas with CCS is deployed.
This case shows the potential of deploying renewables and
nuclear up to the point where public resistance and
complexity become limiting, and deploying a limited
amount of natural gas where it adds the most value, i.e.,
hydrogen production and system balancing.
In each scenario, the model optimizes investment
and hourly dispatch of all the technologies listed in the
Appendix to minimize total system costs. The default
settings of the three critical variables in the scenarios are
1) no increase in grid costs, 2) 6000 €/kW nuclear capital
cost, and 3) 6 €/GJ natural gas export price. A high
CO 2 price of 200 €/ton is assumed in all cases.
The Electricity Mix
Electricity production and consumption from the optimal
technology mixes for different cases are shown in Figure 2.
Starting from the No CCS or Nuclear scenario on the
left, we see that higher transmission costs reduce the
deployment of renewables and increases CO 2 emissions
from unabated natural gas-fired power production. With
the base grid costs (1x) derived from a Berkeley Lab
study 15 , all required hydrogen is made locally using
electrolysis. However, this scenario requires 267 GW of
installed wind capacity (two-thirds onshore) – quadruple
the current installed base in Germany, where public
resistance already has a large negative impact on wind
expansion plans. In addition, 378 GW of solar power is
needed (7x the current level).
When transmission costs are tripled – a likely scenario
given the public resistance and complexity anticipated
from such vast wind and solar deployment – a considerable
amount of unabated natural gas-fired power production
is deployed. Even with a CO 2 price of 200 €/ton, higher
renewable energy integration costs preserve a central role
for unabated natural gas in the power system. In addition,
this case relies on expensive hydrogen imports via green
ammonia for 28 % of the hydrogen demand.
The inclusion of nuclear in the No CCS scenario creates
a near 100 % nuclear system when projects are well
executed to build plants for 4000 €/kW. According to the
latest power plant cost database from the IEA and NEA 16 ,
nuclear plants have investment costs ranging from
2300 €/kW in Korea to 4500 €/kW in the United States, so
such costs are feasible. Even at the baseline cost of
6000 €/kW, nuclear maintains a central role in the power
system. However, at 8000 €/kW (e.g., the Hinkley Point C 17
project), costs become excessive, and the optimal solution
is the same as the base case (1x) in the No CCS or Nuclear
scenario.
When CCS is allowed in the All Technologies scenario,
natural gas-fired power plants with CCS become the
favored technologies at natural gas export prices of 6 €/GJ
and lower. Renewable energy deployment is low because
CCS (and nuclear) plants are best operated as baseload
generators and natural gas is used for all hydrogen
production, removing the possibility of electrolysis to
balance fluctuating wind and solar output. The natural gas
price of the base case (6 €/GJ + transmission) is a little
| Fig. 3.
Optimized costs of the energy system in the different cases. The cost of generating clean electricity
for green hydrogen production (either from renewables or nuclear) is included directly in green
hydrogen costs.
higher than long-term European natural gas prices
projected in the IEA Stated Policies Scenario in the latest
IEA World Energy Outlook 18
and implies large profit
margins for natural gas producers. The IEA’s Pariscompatible
Sustainable Development Scenario projects
natural gas prices below the 4 €/GJ level due to reduced
demand.
When CCS is available, steam methane reforming of
natural gas is used for almost all hydrogen production,
strongly reducing the amount of extra electricity
pro duction needed for electrolysis. Natural gas is only
driven out of the power sector when prices rise to
8 €/GJ, displaced mainly by nuclear. However, it remains
responsible for 94 % of hydrogen production, even at this
high price level.
Finally, the Mix case shows the result when wind and
solar power are forced to levels likely to prevent excessive
public resistance and system complexity: 80 GW of onshore
wind, 40 GW of offshore wind, and 160 GW of solar.
This case also assumes an efficient nuclear rollout at
4000 €/kW and low natural gas prices of 4 €/GJ due to
reduced demand. One-third of hydrogen comes from
electrolysis in this case, which plays a central role in
balancing renewables while nuclear provides baseload
power (see Figure 4 in the Appendix).
Total System Costs
The minimized annual system costs of the different
cases are shown in Figure 3. For the No CCS or Nuclear
scenario, the high costs of unabated natural gas-fired
power production (mainly from the high CO 2 price) are
clearly visible. However, this costly generation remains the
cheapest way to supply power during extended periods of
low wind and solar output. In addition, significant
transmission, storage, and ramping costs are shown.
When transmission costs are tripled (the 3x case), the
model chooses to deploy considerably fewer renewables
to reduce this high integration cost, resulting in much
higher costs from unabated natural gas power plants and
hydrogen imports.
FEATURE | RESEARCH AND INNOVATION 11
15 https://www.sciencedirect.com/science/article/abs/pii/S0301421519305816?via%3Dihub
16 https://www.oecd-ilibrary.org/energy/projected-costs-of-generating-electricity_20798393
17 https://en.wikipedia.org/wiki/Hinkley_Point_C_nuclear_power_station
18 https://www.oecd-ilibrary.org/energy/world-energy-outlook-2020_557a761b-en
Feature
Is Wind the Next Nuclear? ı Schalk Cloete
atw Vol. 66 (2021) | Issue 5 ı September
FEATURE | RESEARCH AND INNOVATION 12
When nuclear plants can be built for 4000 €/kW in
the No CCS scenario, energy system costs reduce
substantially. This case requires no natural gas power
production and almost no added transmission, storage,
and ramping costs. Nuclear plants operate at baseload
conditions with electrolyzers used to balance daily
demand variations, leading to an attractively simple
energy system. Increasing the cost of nuclear to
6000 €/kW brings more wind and solar into the system
with the associated balancing costs. If nuclear costs
escalate to 8000 €/kW, nuclear is too expensive, and the
system reverts to the 1x case in the No CCS or Nuclear
scenario (as shown in Figure 2).
The addition of CCS in the All Technologies scenario
brings further cost reductions, especially with a natural
gas export price of 4 €/GJ. The main benefit of including
CCS is that hydrogen becomes much cheaper. However, a
system that is so dependent on natural gas is undesirable,
and substantially higher shares of renewables and nuclear
would be preferred from the perspective of energy security
and long-term sustainability. Natural gas export prices
need to rise to unrealistic values of 8 €/GJ before nuclear
(at 6000 €/kW) displaces natural gas power plants with
CCS.
Finally, the Mix case illustrates how these three
technology classes (renewables, nuclear, and CCS) can be
combined to create a cost-effective system that avoids the
challenges from over-reliance on any single technology
class. Renewables and nuclear are deployed to levels
where complexity and public resistance are deemed
manageable, allowing for optimistic assumptions (no grid
cost escalations and 4000 €/kW nuclear), while natural
gas demand is minimized, making a low export price of
4 €/GJ seem reasonable. As shown in Figure 3, this case
with 401 TWh/year of natural gas demand is only 10 %
more expensive than the cheapest case that demands an
unrealistic 1743 TWh/year of natural gas.
Conclusions
An over-reliance on any energy technology class can be
detrimental, creating a range of social, political, and
environmental challenges. As discussed in this article, the
hurdles facing wind and nuclear are very different, but
both are highly significant. As wind power continues to
expand to the level where nuclear peaked (it is currently
about one-third of the way there), public resistance and
system complexity will continue to mount, causing
substantial headwinds.
Ultimately, wind and solar will follow the same S-curve
deployment pattern 19 of all other energy technologies, but
the plateau may well come earlier than proponents
believe. For this reason, nuclear and CCS should be
encouraged for parallel deployment, especially in regions
with poorer wind/solar resources or high population
densities. The ability to construct these energy-dense
technologies close to demand and dispatch them as
needed results in a much simpler and less obtrusive
energy system.
An all-of-the-above approach to the energy transition
guided by technology-neutral policies remains the
rational choice. Each technology class has its limits and
weaknesses, and we need a balanced mix to allow each
technology to do what it does best. Cheap wind and solar
are great at moderate deployment levels, but other clean
technologies will be needed to reach net-zero. Nuclear is
one of these options, while CCS has a vital role to play in
system balancing and clean fuel provision.
The global energy transition is a clean energy team
effort. All the players deserve our support.
Appendix: Model Description
A modified version of the energy system model discussed
in a previous article 20 is used in this study to illustrate the
large effects of renewable energy and nuclear cost inflation
caused by the range of techno-socio-economic factors
| Fig. 4.
Hourly electricity generation profile for the “Mix” case. Electricity consumption (mainly electrolyzers and battery charging) is shown as negative generation. NGCC
= Natural gas combined cycle; OCGT = Open cycle gas turbine; SMR CCS = Steam methane reforming with CO2 capture and storage.
19 https://extrudesign.com/what-is-technology-s-curve
20 https://energypost.eu/green-or-blue-hydrogen-cost-analysis-uncovers-which-is-best-for-the-hydrogen-economy/
Feature
Is Wind the Next Nuclear? ı Schalk Cloete
atw Vol. 66 (2021) | Issue 5 ı September
discussed above. The model is loosely based on Germany
and is designed to optimize investment and hourly dispatch
of a range of technologies, including:
p Nine different electricity generators: onshore and
offshore wind, solar PV, nuclear, natural gas combinedcycle
plants with and without CCS, open cycle gas
turbine peaker plants, hydrogen combined and opencycle
plants
p Lithium-ion batteries for electricity storage
p Two clean hydrogen generators: steam methane
reforming with CCS (blue hydrogen) and electrolysis
(green hydrogen)
p Two hydrogen storage technologies: cheap salt
caverns with slow charge/discharge rates and locational
constraints and more expensive storage tanks without
such limits
p Hydrogen can also be imported in the form of
green ammonia that is reconverted to hydrogen in
reconversion plants included in the model
In addition, transmission costs for electricity, hydrogen,
natural gas, and CO 2 are included in the model.
p Electricity transmission is included only for wind and
solar generators, accounting for the distance between
demand centers and high-quality resources in publicly
accepted regions. The base case assumes 300, 500,
and 200 €/kW of added grid costs for onshore wind,
offshore wind, and solar PV, respectively.
p Hydrogen and natural gas transmission costs are
included for hydrogen- and natural gas-fired power
plants and steam methane reforming plants. Despite
natural gas pipelines being cheaper than hydrogen
pipelines, natural gas pipeline costs are set to 200 €/kW
relative to 150 €/kW for hydrogen because natural gas
needs to be imported from abroad, whereas hydrogen
is only transmitted locally between producers and
consumers.
p Hydrogen transmission costs to locationally constrained
salt caverns are also included. These costs
are assumed to escalate from 100 to 500 €/kW as
capacity increases, accounting for the fact that
intermittently operated electrolyzers co-located with
wind and solar (see next point) will first exploit
sites close to salt caverns before more distant sites
need to be used.
p Electrolyzers are assumed to be co-located with
wind and solar plants to avoid the electricity
transmission costs mentioned in the first point. These
electrolyzers are assumed to avoid transmission
capacity costing 300 €/kW in exchange for added
hydrogen transmission costs of 150 €/kW. Since
electrolyzers consume more electricity than they
produce hydrogen, the net saving is about 200 €/kW of
transmission capacity – a substantial benefit.
p CO 2 transport and storage infrastructure costs are
added to CCS power and hydrogen plants. High costs
are assumed, given the high resistance to CCS in
Germany, amounting to levelized costs of 23 €/ton
when CCS plants are operated at the maximum
allowable capacity factor of 90 % (costs escalate
with lower capacity factors).
In the No CCS or Nuclear scenario, the electricity,
hydrogen, and natural gas transmission costs are
increased to 2x and 3x the default levels to account for
the following factors:
p The need to build turbines in more isolated sites or
far offshore to satisfy local stakeholders
p Avoiding public resistance to grid expansions via
expensive underground transmission lines
p Having to resort to sites with lower quality wind or solar
resources
p Paying fees to local communities to allow construction
closer to demand centers
p Potentially large end-of-life recycling and disposal costs
of solar panels and turbine blades
p A sub-optimal buildout of the complex and highly
interdependent systems required to integrate high
shares of wind and solar
Costs related to ramping natural gas and nuclear power
plants are also included, amounting to 20 % of the total
annualized fixed cost in €/kW/year per MW of up or down
ramp.
In all cases, total annual electricity demand is set to
the fluctuating hourly profile observed for Germany
in 2018, requiring a total of 499 TWh of production
per year. In addition, flat demand for hydrogen of
400 TWh/year and additional electricity (increased
electrification) of 200 TWh/year is included. This extra
hydrogen and electric energy is equivalent to about a
third of German non-power oil & gas consumption,
implying that great efficiency advances and more clean
energy deployment will be needed to reach net-zero
emissions.
The GAMS software is used to minimize total system
costs by optimizing the deployment and hourly dispatch of
all production, transmission, and storage technologies. To
keep computational costs reasonable, only every 7 th hour
is simulated. A previous sensitivity analysis 21 has shown
that this assumption still yields accurate results.
As an illustration, hourly power production profiles
for the balanced Mix case are shown in Figure 4. The good
seasonal complementarity between wind and solar in
Germany is clearly observed. Nuclear’s baseload role is
also illustrated with electrolyzers and batteries mainly
responsible for balancing wind and solar power. Natural
gas power plants run only during isolated instances of high
demand and low renewable energy output.
Author
Schalk Cloete
Research Scientist
SINTEF
Trondheim, Norway
Schalk.Cloete@sintef.no
Schalk Cloete is a research scientist working on solutions to our great 21 st -century
sustainability challenge: give every world citizen a fair shot at a decent life without
destroying the ecological carrying capacity of our planet. After reaching early
financial freedom, he retired from the research rat race and is currently 40 %
employed at the Norwegian research institute, SINTEF, where he develops novel
clean energy conversion technologies. His free-time research is dedicated to
policy and lifestyle design strategies for a rapid and just transition to a sustainable
global society.
FEATURE | RESEARCH AND INNOVATION 13
21 https://www.econstor.eu/handle/10419/234469
Feature
Is Wind the Next Nuclear? ı Schalk Cloete
atw Vol. 66 (2021) | Issue 5 ı September
14
INTERVIEW
“Since the Beginning, FORATOM has
Advocated for the Taxonomy to Follow
a Technology Neutral Approach.”
Interview with Yves Desbazeille ı Director General of FORATOM
Yves Desbazeille
Director General of FORATOM
Yves Desbazeille is French and graduated in electrical
engineering from the Ecole Supérieure d’Electricité (“ SUPELEC”)
in France in 1991 and studied on an MBA program in the early
2000s. During his successful career, he has been involved in
different businesses and responsibilities at EDF: nuclear
engineering, hydro and thermal power projects management in
France, USA as well as in Asia, where he was for 5 years. His
previous position as EDF representative for energy in Brussels
has provided him with an in-depth knowledge of the EU
institutions and Brussels’ stakeholders and of the energy and
climate stakes for Europe.
FORATOM is the Brussels-based trade association for the nuclear
energy industry in Europe. FORATOM acts as the voice of the
European nuclear industry in energy policy discussions with EU
Institutions and other key stakeholders. The membership of
FORATOM is made up of 15 national nuclear associations
representing nearly 3,000 firms.
The association provides information and expertise on the role of
nuclear energy; produce position papers, newsfeeds, responses
to public consultations, analyses of public opinion; organise
regular networking events like dinner debates, workshops, oneon-one
meetings, press briefings and visits to nuclear facilities.
For more than two years now FORATOM and other
industry associations, environmental organizations,
company representations and political institutions
were occupied with the EU Sustainable Finance
Initiative and the pivotal taxonomy of sustainable
activities. What were FORATOMs primary activities
in this respect?
The first action undertaken by FORATOM was to reach out
to all its members in order to draw attention to the file
under development and to invite them to share their
thoughts on how it could potentially impact the European
nuclear sector. This enabled the industry to develop its
position and desired outcome, providing FORATOM
with the tools to liaise with the EU institutions.
FORATOM furthermore established contact with other
stakeholders (including civil society) to inform them of the
European Commission’s plans and to share FORATOM’s
position.
Since the beginning, FORATOM has advocated for the
taxonomy to follow a technology neutral approach. It
has constantly reiterated the message that, in order to
identify whether an energy source is sustainable or not, it
is important to evaluate each source on the basis of
objective criteria (including CO 2 emissions, air pollution,
raw material consumption and land use impacts) and
using a whole life-cycle approach. More information about
this can be found in our position paper “Sustainable
Finance: FORATOM calls for equal treatment of all lowcarbon
technologies”.
In terms of advocacy and outreach, FORATOM focused
on two elements:
p The so-called ‘Taxonomy Regulation’: Together with
its members, FORATOM established contacts with the
Council and nuclear supportive Members of the
European Parliament (MEPs). These two played a key
role in the decision-making process. In this respect, we
were successful in ensuring the Regulation underlines
the need for the taxonomy to be technology neutral.
p The Technical Screening Criteria of the taxonomy: At
the start of the process, FORATOM and its members
applied to form part of the technical expert sub-groups
established by the European Commission working on
this. FORATOM ensured close liaison with those on the
sub-groups by gathering all useful reports and studies
which supported the message that nuclear is sustainable.
Here the work proved very challenging as the
group included anti-nuclear organisations. Due to
a split position, the Technical Expert Group recommended
that nuclear be assessed by a group of experts
with an in-depth knowledge of the nuclear life cycle as
they did not feel that they had the right expertise. As a
result, nuclear was neither included nor excluded from
the taxonomy, and the Commission proceeded with
mandating its Joint Research Centre to conduct this
assessment.
Following on from this, the JRC published its “Technical
assessment of nuclear energy with respect to the ‘do no significant
harm’ criteria of Regulation (EU) 2020/852 (‘Taxonomy
Regulation’)” at the end of March 2021. This report
was then reviewed by the following expert groups which
submitted their opinions on 2 July 2021:
p Opinion of the Group of Experts referred to in Article 31
of the Euratom Treaty on the Joint Research Centre’s
Report
p SCHEER review of the JRC report on technical
assessment of nuclear energy with respect to the ‘do no
significant harm’ criteria of Regulation (EU) 2020/852
(‘Taxonomy Regulation’)
Interview
“Since the Beginning, FORATOM has Advocated for the Taxonomy to Follow a Technology Neutral Approach.” ı Yves Desbazeille
atw Vol. 66 (2021) | Issue 5 ı September
At the time of writing, FORATOM and its members
continue to liaise with the Member States and MEPs to
ensure that the Commission takes on board the conclusions
of the experts and proceeds with the inclusion of nuclear
under the taxonomy.
As nuclear received a special treatment with
dedicated specific reports, the third of which was
published in July, what were the arguments against
including this obviously low carbon, low environmental
impact technology both in the taxonomy
process and in the political battle fields around it?
Regarding the Technical Experts Group (TEG), and as
mentioned above, they made clear that they did not have
the right expertise to assess nuclear. We fully respect this
conclusion of the TEG, as
indeed for such scientific
decisions it is essential
that they are taken by
those with real expertise
in the field. But of course,
it meant that nuclear
found itself in a sort of
‘limbo land’ as it was
neither included nor excluded.
What was very
positive was that the TEG made it clear that nuclear
contributes to climate mitigation objectives.
The two areas where the TEG were less certain related
to:
p Potential data gaps in relation to the Do No Significant
Harm criteria
p The long-term management of High-Level Waste
(HLW)
These are valid concerns, and as a result this is what the
JRC – as nuclear experts – was asked to focus on. The result
of this assessment has provided a clear response to both
these questions as follows:
p Based on the scientific evidence available nuclear does
not cause more harm than any of the other power
producing technologies currently deemed to be
taxonomy-compliant
p Deep Geological Repositories provide an appropriate
and safe solution for the management of HLW.
Against this backdrop there have of course been other
opinions expressed against nuclear. Here, a broad range of
arguments have been raised, including public opposition
to nuclear, the risk of proliferation, the impact of nuclear
accidents and radiation exposure. But it is our belief that
the work of the JRC experts provides a robust rebuttal to
these claims.
In the long-term, if certain policymakers are
successful in getting nuclear excluded from
the taxonomy for political reasons, this could
mean that nuclear no longer has access to
any form of finance, be it State Aid or private
investment. This would essentially spell the
end of the European nuclear industry.
What is actually at stake for nuclear in the sustainable
finance initiative and taxonomy?
There are two main issues at stake for the nuclear industry.
First of all, access to finance. The goal of this taxonomy
is to encourage investors to redivert funds towards those
activities classed as sustainable. Given that the nuclear
industry has high upfront capital costs, access to private
finance at an affordable interest rate is key. By encouraging
investors to move away from ‘non-compliant’ activities, a
political decision to exclude nuclear will severely hamper
its ability to raise funds for the financing of projects. Given
that companies will already be obliged to report on the
share of their activities which are taxonomy-(non)compliant
as of 1 January 2022, we already expect to see this
lack of clarity around nuclear having a negative effect not
just on utilities, but also large companies active in the
nuclear supply chain.
Secondly, it will have a broader political impact. EU
legislation is already being modified to align it to the
taxonomy. Take for example the recent EU recovery fund.
In order to access EU funds and loans under this package,
Member States have to put forward national Recovery and
Resilience Plans (RRPs). According to the legislation, 37 %
of the funds allocated must go towards taxonomy
compliant activities, and the Commission has already
confirmed to us that, as a decision on nuclear has yet to be
taken, nuclear related projects cannot count towards this
37 %. For the remainder of the funds, projects must meet
the Do No Significant Harm principle, again raising the
question as to how nuclear is to be treated under the RRPs.
It should be noted that the
EU is currently reviewing its
Climate, Energy and Environmental
State Aid Guidelines
and the pro posal on the table
makes a direct link to the
taxonomy, suggesting that
the EU is contemplating
reviewing its State Aid legislation
in order to align it to
the taxonomy...
In the long-term, if certain policymakers are successful
in getting nuclear excluded from the taxonomy for political
reasons, this could mean that nuclear no longer has access
to any form of finance, be it State Aid or private investment.
This would essentially spell the end of the European nuclear
industry.
Where are we now in the decision-making process
and what will happen next, who will decide what
in the end and who could block what?
The Council and the European Parliament are now being
asked to vote on the first Delegated Act (DA), which covers
the climate mitigation and adaptation aspects of the
taxonomy. These two institutions have two options: they
can either adopt or reject the DA. They cannot modify it.
The process being followed is called a ‘Scrutiny period’,
under which they have 4 months to take a decision (with
the potential to extend this by a further 2 months).
Whilst this DA covers technologies under the energy
sector, it does not include nuclear and natural gas. In this
respect, the Commission has
been waiting for the conclusion
of the nuclear assessment in
order to decide on whether to
include it under a complementary
Delegated Act (cDA).
This cDA is expected to be
made public anytime between
September and November
2021. Like other DAs, a draft
We understand
that discussions are
ongoing within
the Commission
as to what to do
with nuclear.
cDA will be published and subject to a one-month public
consultation. After this, the cDA will be sent for ‘scrutiny’
following the process mentioned above.
As to who could block what, this remains an open
question. First of all, because we understand that
discussions are ongoing within the Commission as to what
to do with nuclear. It has been suggested that some are
already pushing for nuclear to be excluded from the cDA
for political reasons, regardless of the fact that the experts
conclude that it is sustainable (and thus taxonomy
compliant). This is the first hurdle to be overcome.
INTERVIEW 15
Interview
“Since the Beginning, FORATOM has Advocated for the Taxonomy to Follow a Technology Neutral Approach.” ı Yves Desbazeille
atw Vol. 66 (2021) | Issue 5 ı September
INTERVIEW 16
Secondly, even if nuclear is added to the cDA, it is
possible that the Technical Screening Criteria are much
more stringent than those proposed in the JRC’s assessment,
thus making it virtually impossible for any project to
comply with them.
And finally, once it goes to the Council and Parliament,
we expect to see those who are against nuclear strongly
pushing for the cDA to be rejected.
Besides this major issue, other nuclear developments
have been going on. FORATOM has signed a
MoU with the Canadian Nuclear Association. What
are the major goals for this cooperation?
FORATOM is in the process of signing a series of
Memoranda of Understanding (MoUs) with several
national nuclear associations. The overarching goal of
these is to strengthen cooperation on an international level
and to promote nuclear as a clean source of energy. In
addition to the one signed with the Canadian Nuclear
Association (CNA), FORATOM is also in discussions with
the US Nuclear Energy Institute (NEI) and the Japanese
Atomic Industry Forum (JAIF).
The main focus of the MoU signed with the CNA is
to promote clean, innovative and advanced nuclear
technologies. In this respect, it focuses on the following:
p advocating for more explicit and
prominent inclusion of nuclear
energy in Europe and Canada’s
energy and environmental policies;
p support for innovation in nuclear
energy, specifically the development
and deployment of small
modular reactors and advanced reactors;
p Identify and implement initiatives where FORATOM
and CNA could work together to promote nuclear as a
clean energy source to meet climate change goals,
reduce emissions and improve the quality of life.
As the European trade association, FORATOM’s clear goal
is to influence EU policy. But as we all know, climate
change is a global issue and it is for this reason that we find
it essential to work with our partners at international level.
Some of the initiatives where FORATOM is playing a
greater role, together with its partners, include the UN
Climate Conferences (ie COP) and the Clean Energy
Ministerial (CEM) Nuclear Innovation: Clean Energy
Future (NICE Future).
At international level, it is also important to note that
for several years FORATOM has increased relations with
institutions such as the IAEA, the OECD-NEA. It is also
member of the “Global leader summit” gathering together
the Managing Directors of all these organizations
Likewise, it is important
to note that the existence
of the Euratom Treaty
might be threatened.
What are other topics on Brussels agenda that
concern the nuclear industry, like e. g. the Hydrogen
Strategy of the EU?
There are an increasing number of policy files which are of
direct relevance to the nuclear industry. Those which are
currently on the table and which FORATOM is actively
engaging in can be summarised as follows:
p Fit for 55 package: The main focus of this package is to
review existing legislation and align it with the EU’s
target of reducing CO2 emissions by at least 55 % by
2030 ( compared to 1990 levels). It covers a broad range
of legislation such as the EU’s Emissions Trading
Scheme and the proposal for a Carbon Boarder
Adjustment Mechanism, as well as a revision of the
Renewable Energy and Energy Efficiency Directives.
p Industrial strategy: This initiative looks at, for
example, how to reduce industrial emissions, whilst at
the same time maintaining industry’s competitiveness
including access to affordable energy. Workforce and
skills are also issues dealt with under this strategy.
p Energy System Integration and the Hydrogen
Strategies: These two strategies aim to support a more
efficient and interconnected low-carbon energy sector.
The goal is to ensure a constant supply and access to
low-carbon energy sources.
p Guidelines on State aid for environmental protection
and energy: As mentioned above, the EU is
looking to review these guidelines, including suggestions
of aligning them more closely to the Taxonomy
Regulation.
There are of course many other issues which FORATOM
is actively engaged in. For example, there are several
Innovation, Research and Development projects which
are under development and which receive EU support.
Developments relating to the Espoo and Aarhus
Conventions, respectively dealing with environmental
impact assessments and access to Information, public
partici pation in decision-making and access to justice in
environmental matters, also require constant monitoring,
because, despite not being purely nuclear, they can have a
serious impact on the nuclear activities.
Likewise, it is important to note that the
existence of the Euratom Treaty might be
threatened – indeed, in the latter instance
several Member States continue to push for
this Treaty to be reopened, modified and
potentially revoked....
Another topic that we are actively working on, even if it
is not related to one specific EU policy file, is the long-term
operation of the existing nuclear fleet. Given the stringent
decarbonization goals which the EU has set for 2030,
FORATOM strongly believes that more attention needs to
paid to this. As LTO (Long Term Operation) remains the
cheapest form of electricity across the board, prolonging
the existing fleet would be the best way of achieving the
2030 targets in an affordable manner.
In national energy policies we have seen some
major developments recently, such as Belgium
opting for nuclear phase-out and fossil gas phase-in,
the Polish nuclear program consolidating and a
very interesting debate about new nuclear power
in the Netherlands. Can you give us a brief overview
on these and possibly other developments of this
kind in the EU or in Europe?
With the UK leaving the EU, we have of course lost one of
the biggest nuclear advocates at Brussels level and this has
made our task a bit more challenging. But at the same
time, we are seeing other Member States pick up where the
UK has left off. For example, France has become much
more vocal in its defence of nuclear in relevant discussions.
Furthermore, several Eastern Member States have been
sending a very clear message to Brussels that in order to
achieve the ambitious climate targets set by the EU, nuclear
must be recognized as part of the solutions. Their main
For example, France
has become much
more vocal in its
defence of nuclear in
relevant discussions.
argument is that they have a
long way to go to decarbonize
their economies and
therefore they need to be
allowed to use all lowcarbon
technologies to
ensure that the transition is
Interview
“Since the Beginning, FORATOM has Advocated for the Taxonomy to Follow a Technology Neutral Approach.” ı Yves Desbazeille
atw Vol. 66 (2021) | Issue 5 ı September
both affordable and does not lead to a shortage in energy
supplies (nor increased dependence on energy and raw
material imports...).
Finland has always been supportive to nuclear, and it
has been very interesting to see that even the Finnish
Green party is taking a more pragmatic approach to
nuclear by recognizing that the fight we have today is
against climate change and that nuclear may form part of
the solution. Public opinion of nuclear in Sweden is also at
an all-time high.
The same can be said for the Netherlands, where they
are currently considering the development of a new
nuclear project as they recognize that it has a role to play in
terms of decarbonizing the energy sector and ensuring
security of supply. But of course, there are Member States
which remain staunchly anti nuclear, namely Austria,
Germany and Luxembourg. Belgium and Spain are also
increasingly leaning towards this more ‘anti’ camp.
What we can say, though, is that many are showing a
great interest in Small Modular Reactors (SMRs). One
example of this is Estonia, which is seriously considering
SMRs as a potential solution for their energy mix which is
currently very CO 2 intensive.
Quite a number of think tanks and international
institutions have stressed the importance of nuclear
for reaching climate policy goals, many governments
agree, including recently the Biden administration
in the US. Which position on nuclear will prevail in
EU institutions in your opinion, that of fundamental
critics aiming for phase-out sooner or later or of
nuclear optimists envisioning a long term and
possibly growing role in a low carbon energy
system?
As indicated above, the EU remains very divided on the
issue of nuclear. The Treaties make it clear that each
Member State is free to choose its own energy mix, and
whether that includes or excludes nuclear is a national
prerogative. Of course, this does not prevent anti-nuclear
Member States trying to make
it as difficult as possible for
other to get nuclear projects
off the ground.
This discord is being felt
at EU level, with some
pushing for EU legislation
which de facto excludes nuclear.
Examples include the Just Transition Fund and
Invest EU, both of which automatically exclude nuclear
projects from having access to these funds without
providing any real justification for such an exclusion.
At the same time, many reputable organizations
continue to highlight the importance of nuclear in the fight
against climate change. Take, for instance, the latest IEA
report entitled ‘Net Zero by 2050’. According to this report,
nuclear energy will make “a significant contribution” in
the Net Zero Emission Scenario and will “provide an
essential foundation for transitions” to a net-zero emissions
energy system.
For us, it is essential that EU policy remain credible –
and this means basing policy on science. Let’s be clear: we
have less than 30 years to fully decarbonize our economy
and taking political decisions with no scientific justification
will lead us nowhere. This is why, as FORATOM, we
continue to insist that the EU adopt a technology neutral
approach to policy making which is based on the advice of
science and experts.
Let’s be clear: we have less than
30 years to fully decarbonize our
economy and taking political
decisions with no scientific
justification will lead us nowhere.
Given the opportunity, nuclear will be a help, not a
hindrance. Why?
First of all, because it is low-carbon and so it helps
achieve the decarbonization targets.
Secondly, it is available 24/7 and will ensure that
citizens and business have access to the energy they need
when they need it.
And finally: because it is affordable. Yes, nuclear project
come with high upfront costs. But they also have a long
lifespan of +60 years and require much lower system
costs.
Societal and political acceptance are key to the
application of nuclear power. But nuclear energy is
also a springboard for other political interests, not
power related. What are your expectations of
national and European policies to break this knot?
Nuclear power is indeed at the centre of many (heated)
debates at EU level. Most people are not actually aware of
the other solutions provided by nuclear. Let’s take, for
example, medical applications. The EU is a front runner
when it comes to the production of medical isotopes. And
yet very little is said about this – although let’s be clear,
many of those who are against nuclear energy are also
against its other applications....
As FORATOM, we are trying to draw more attention to
these other applications with, for example, the publication
of a position paper which focuses on medical uses of
nuclear technology, and which aims to respond, in part, to
the EU’s Beating Cancer Plan. We are also increasingly
highlighting the benefits which nuclear can bring in terms
of low-carbon hydrogen production, industrial applications,
space etc.
What people don’t necessarily realize is that legislative
proposals that aim to block nuclear energy could, in the
long term, also negatively affect these other applications.
For example, the taxonomy will in future cover other
sectors, potentially even healthcare. If nuclear power is
excluded, then this will potentially be used as an excuse to
Author
also leave out all medical uses as well.
What we need is for the Member States
to continue to fly the flag for nuclear. They
play a key role in the EU decision-making
process. And in this respect, FORATOM
and its members stand ready to support
the Member States in any which we can.
Nicolas Wendler
Head of Media Relations and Political Affairs
KernD (Kerntechnik Deutschland e.V.)
nicolas.wendler@kernd.de
INTERVIEW 17
Interview
“Since the Beginning, FORATOM has Advocated for the Taxonomy to Follow a Technology Neutral Approach.” ı Yves Desbazeille
atw Vol. 66 (2021) | Issue 5 ı September
18
OPERATION AND NEW BUILD
Operating Experience from Ageing
Events Occurred at Nuclear Power Plants
Antonio Ballesteros Avila and Miguel Peinador Veira
Introduction Nuclear safety of the operating nuclear power plants (NPP) has to be in the core of their life
management. NPPs have to be operated safely and reliably. European countries involved in nuclear energy are spending
their efforts in improving the safety of the operating plants and of those under construction, in accordance with the
Euratom Treaty obligations [Euratom Treaty, 2012]. In this respect, the IAEA requirements for the safe operation of
nuclear power plants identify, among others priorities, maintenance, testing, surveillance and inspection programmes
and ageing management of safety related components [IAEA, 2018].
Recognising the importance of peer
review mechanisms in delivering
continuous improvement to nuclear
safety, the amended Nuclear Safety
Directive [European Union, 2014]
introduced a European system of
topical peer reviews (TPR). The
subject “Ageing Management” was
chosen in 2017 as the first TPR exercise
on the basis of the age profile and
the potential long term operation
of European NPPs. The national
assessment reports [ENSREG, 2018]
prepared under this first TPR gave
numerous examples where operating
experience (OPEX) has been used to
inform ageing management. There are
many existing fora for sharing OPEX.
For example, the International Reporting
System (IRS) [IAEA, 2010]
and the International Generic Lessons
Learned Programme (IGALL) [IAEA,
2014] [IAEA, 2020] managed by the
IAEA, the Committee on Nuclear
Regulatory Activities (CNRA) and
the Committee on the Safety of
Nuclear Installations (CSNI) under the
OECD-NEA, and the European
Clearinghouse on Operating Experience
Feedback of the Joint Research
Centre (JRC) of the European
Commission [JRC, 2021] [Ballesteros
A., Peinador M., Heitsch M., 2015].
The original design life of structural,
mechanical and electrical components,
particularly those that technically limit
the power plant operation (e.g. reactor
pressure vessel, containment, etc.),
was originally estimated to be around
30-40 years, considering anticipated
operational conditions and ambient
environment under which they are
operated. In reality, the plant operational
conditions and ambient environment
parameters are below the limits
established during the initial design.
While economical feasibility falls into
the operating organization competence,
a decision regarding the plant
safety level depends on country’s
regulatory requirements. Generally, a
thorough technical assessment of
the plant physical condition is needed
to identify safety enhancements or
modifications, and the impact of
changes to NPP programmes and
procedures necessary for continued
safe operation.
Many operators in Europe have
expressed the intention to operate
their nuclear power plants for longer
than envisaged by their original
design. From a nuclear safety point of
view, continuing to operate a nuclear
power plant requires two things:
demonstrating and maintaining plant
conformity to the applicable regulatory
requirements; and enhancing
plant safety as far as reasonably
practicable. Depending on the model
and age of the reactor, national
regulators assume that granting longterm
operation programmes will
mean extending their lifetime by 10 to
20 years on average.
There are 106 nuclear power
reactors in operation in the European
Union (EU) in 13 of the 27 EU countries.
The age distribution of current
nuclear power plants is shown in
Figure 1. A major part of the EU
reactors are between 31 to 40 years
| Fig. 1.
Age distribution of the EU operating nuclear power reactors.
old. Hence, from both the safety and
security of supply viewpoints, ageing
of these power plants is of increasing
concern to European policy makers,
citizens and utilities.
Methodology
The final objective of this work is to
draw case-specific and generic lessons
learned from ageing related events
occurred at NPPs during a period of
approximately 10 years. Namely,
events reported between 01/01/2008
and 30/06/2018 in the IAEA IRS
database. The IRS is an international
database jointly operated by the
International Atomic Energy Agency
(IAEA) and the Nuclear Energy
Agency of the Organisation for
Economic Cooperation and Development
(OECD/NEA). The IRS was
established as a simple and efficient
system to exchange important lessons
learned from operating experience
gained in nuclear power plants of the
IAEA and NEA Member States. The
IRS database contains more than
4500 event reports with detailed
descriptions and analyses of the
event’s causes that may be relevant to
other plants.
Operation and New Build
Operating Experience from Ageing Events Occurred at Nuclear Power Plants ı Antonio Ballesteros Avila and Miguel Peinador Veira
atw Vol. 66 (2021) | Issue 5 ı September
Key word
Aging / ageing
Creep
Relaxation
Fatigue
“Irradiation damage”
Corrosion
Wear
Erosion
“Material degradation”
Deformation
Embrittlement
Cracking
Total
| Tab. 1.
Number of event reports in the IRS database.
The screening of ageing related
events was carried out in two steps:
p Step 1: The query capabilities of
the IRS database are used to
retrieve an initial list of potentially
relevant events.
p Step 2: The reports obtained from
the previous step are briefly
reviewed to confirm their relevance.
Even if apparently relevant,
a report could be screened out if it
is insufficiently detailed or if its
quality is too low to be useful for
the purposes of the study.
The query result in the IRS database
for the period 01/01/2008 –
30/06/2018 was a list of 173 ageing
event reports (step 1), which were
reviewed to confirm their relevance.
The querying results are summarized
in Table 1, where the number of event
reports is given together with the
guide words used for the screening.
IRS allows querying ageing events
using the IRS code 5.7.5. But it was
noted that some ageing events were
not classified under this specific code.
For that reason querying was also
carried out by searching ageing events
using different degradation mechanisms
and their consequences.
After detailed analysis of the 173
event reports (step 2), only 113
reports were considered as relevant.
All the reports were thoroughly
reviewed in order to characterise the
events. To facilitate this process, the
events were classified according to
the following criteria: plant status, the
means of detection, the systems
affected, the components affected, the
Number of IRS event reports
(search is performed in the Root Causes section
of the IRS reports or in the full reports, depending
on the case. For Aging/Ageing the IRS criterion
5.7.5 is applied)
Search by the IRS Criterion 5.7.5: 60 events
+ 4 events related to Ageing no categorised as 5.7.5
6 in full report
7 in full report
31 in Root Causes
1 in full report
41 in Root Causes
21 in Root Causes
9 in Root Causes
5 in full report
24 in Root Causes
12 in full report
22 in Root Causes
173 event reports
(taking into account that the same report
may be retrieved with different key words)
direct cause, the root causes, the
ageing mechanisms, the conse quences
and the corrective actions. Further to
the classification of events, the reports
are also reviewed to identify the
aspects of the event that can be
used as feedback from operating
experience. These «low-level lessons
learned» are attached to specific
events, and generally can be understood
only in the context of those
events. For this reason, an effort has
been done to define «high-level
lessons learned», or simply «lessons
learned» defined in such a way that
they are not too specific (so that they
are applicable only to one single
plant) nor too wide (so that they can
be considered as common sense, and
already known to everybody).
Analysis of events
This section presents the result of the
screening and classification process
described above. The number of
events for each family in a given category
(plant status, detection, affected
system, affected component, direct
cause, root cause, ageing mechanism,
consequences, corrective actions) is
shown in Table 2.
It was interesting to calculate the
average age of the nuclear power
plant when the event occurred. This
can be expressed by:
Average Age =
where,
n = final number of selected ageing
events
t 2 = time when the event happen
t 1 = time when the plant started
operation
The analysis provides an Average Age
of 28 years (331 months) with a large
standard deviation of 10 years (123
months) and a median of 30 years
(357 months). In other words, on
average, ageing related events occur
after 28 years from the start of reactor
operation.
Selected event reports have been
characterised according to the criteria
defined for this study: plant status,
detection means, affected system,
affected component, direct cause, root
cause, ageing mechanism, consequences
and corrective actions. The
most relevant findings are highlighted
below.
Plant status and
detection means
Figure 2 (left) shows the event distribution
related to plant status. Nearly
half of the events took place during
power operation. Figure 2 (right)
indicates that the major part of the
events were detected by “fault report
in control room” (58 %) followed by
“periodic test / in-service inspection”
(26 %). The fact that one of four
ageing events were detected in
periodic tests or in-service inspections
highlights the importance of having
sound inspection and maintenance
programmes to avoid sudden failures
during power operation with greater
implications on nuclear safety.
Systems and components
affected
The distribution of events per system
affected is presented in Figure 3.
The largest percentage (36 %) corresponds
to the primary reactor systems,
followed by electrical systems
(21 %) and essential auxiliary systems
(13 %).
The distribution of events per component
affected is given in Figure 4.
Passive and active mechanical components
are the most affected components
(38 % and 34 %, respectively),
followed by electrical (16 %),
I&C (9 %) and structural components
(3 %).
Direct and root causes
Figure 5 indicates that the main direct
cause was mechanical failure. The
distribution of root causes is given
in Figure 6. A maximum of three
different root causes was attributed
to each event. Deficiencies in maintenance
or surveillance is the most
important root cause, followed by
OPERATION AND NEW BUILD 19
Operation and New Build
Operating Experience from Ageing Events Occurred at Nuclear Power Plants ı Antonio Ballesteros Avila and Miguel Peinador Veira
atw Vol. 66 (2021) | Issue 5 ı September
Plant status
N. events
Root cause
N. times
OPERATION AND NEW BUILD 20
Power operation 54
Startup 7
Hot standby 2
Hot shutdown 2
Cold shutdown 12
Refuelling 20
Other or Unknown 16
Dectection of events
N. events
Periodic test / In service inspection 29
Fault report in control room 65
Work surveillance 6
Supplementary inspection 4
Other or Unknown 9
Affected system
N. events
Primary reactor systems 41
Reactor auxiliary systems 12
Essential service systems 1
Essential auxiliary systems 15
Electrical systems 24
Feed water, steam and power conversion systems 5
I&C systems 5
Service auxiliary systems 3
Structural systems 5
Other 2
Affected comp.
N. events
Passive mechanical components 43
Active mechanical components 38
I&C components 10
Electrical components 18
Structural components 4
Direct cause
N. events
Mechanical failure 83
Electrical failure 17
I&C failure 9
Structural failure 3
Other 1
Absent Ageing Managemet Programme 12
Deficiencies in Ageing Management Programme 25
Deficiencies in maintenance or surveillance 55
Wrong material selection 15
Equipment specification, manufacture, storage and installation 18
Deficiencies in design 30
Other or unknown 4
Ageing mechanism
N. times
Swelling 1
Relaxation 3
Fatigue 28
Thermal ageing 13
Irradiation damage 2
Corrosion 38
Wear 15
Erosion 4
Electrical ageing 15
Creep 1
Chemical ageing 1
Other 13
Unknown 3
Consequences
N. events
Degradation (damage) 28
Deformation 12
Embrittlement and cracking 36
Material loss 30
Other or Unknown 7
Corrective Actions
N. times
Equipment replacement or repair 112
Monitoring and/or inspection improvement 39
Changes in operation modes 8
Changes in maintenance programme 50
Changes in ageing management programme 18
Design modification 25
Other 2
| Tab. 2.
Number of events/times per family.
deficiencies in design and in ageing
management programmes. To this
respect, we infer that the establishment
of an effective ageing
management programme, as early
as possible in the lifetime of the
plant, will significantly contribute to
preventing events and the resulting
consequences.
Ageing mechanisms
The category “ageing mechanism”
was split in 13 families, as indicated
in Table 2, making it possible to
allocate several (maximum three)
ageing mechanisms to a single event.
Figure 7 shows that corrosion
(38 times) is the main cause of failure,
followed by fatigue (28 times). Other
important contributions are coming
from thermal ageing, wear and
electrical ageing.
As it will be showed later in the
section on lessons learned, many
events only appear after long term
operation of an aged component or
material, and the main cause was a
deficiency in design that was latent.
Figure 8 put some light on this issue
and illustrates that fatigue is the main
degradation mechanism in relation
to hidden deficiencies in design.
Figure 9 correlates deficiencies (or
absence) in ageing management
programme with the ageing mechanism.
In this case electrical ageing is
the most relevant contributor to
failure. This indicates the need for
improvement of the ageing management
programmes of electrical and
I&C components.
Consequences and corrective
actions
Figure 10 shows the distribution of
events among different consequences.
36 events were related to embrittlement
and cracking and 30 events
to material loss (mainly due to
corrosion).
Figure 11 illustrates the corrective
actions. A maximum of three corrective
actions were allocated to a single
event. As expected, the main corrective
action was the replacement or
repair of equipment. Changes in maintenance
programme was the second
Operation and New Build
Operating Experience from Ageing Events Occurred at Nuclear Power Plants ı Antonio Ballesteros Avila and Miguel Peinador Veira
atw Vol. 66 (2021) | Issue 5 ı September
| Fig. 2.
Plant status (left) and detections (right) means versus number of events.
OPERATION AND NEW BUILD 21
| Fig. 3.
Number of events (%) per system affected.
| Fig. 4.
Number of events per component affected.
| Fig. 5.
Number of events per direct cause.
| Fig. 6.
Distribution of root causes.
most usual corrective action followed,
in this order, by monitoring or inspection
improvement, design modification
and changes in ageing
management programme.
Lessons learned
The extraction of the lessons
learned from the operating experience
has been completed in two steps.
First (step 1), low level lessons learned
were retrieved from the IRS database,
or developed in some cases, for a large
number of the 113 analysed events. A
total of 110 low level lessons learned
were obtained. They are given,
together with a short summary of the
events, in Annex 2 of reference
[ Ballesteros Avila A., 2019]. Several
lessons are allocated to the same event
in many cases. These low level lessons
learned are very specific, so that they
would have a too limited applicability.
To address this issue, the low level
lessons learned were grouped under
similar topic or underlying key
message to get a high level lesson
learned (step 2). In the following
paragraphs the high level lessons
learned are presented:
Lesson learned #1 – Appropriate
measures should be taken and design
features should be introduced in the
design stage to facilitate effective
ageing management throughout the
life of the plant.
Lesson learned #2 – Ageing
Management Programmes as well as
maintenance programmes should be
reviewed and updated to take into
account modifications in the current
licensing bases.
Lesson learned #3 – The monitoring
of the environmental conditions,
as information source for ageing
management, is of high importance.
In particular, a review of possible
changes in environmental conditions
(e.g. temperature, radiation, etc.) that
could affect ageing should be performed
in case of operational changes
or structures, systems and components
(SSC) modifications.
Lesson learned #4 – The maintenance
and inspection programmes
should be evaluated and, if considered
necessary, updated (frequency,
Operation and New Build
Operating Experience from Ageing Events Occurred at Nuclear Power Plants ı Antonio Ballesteros Avila and Miguel Peinador Veira
atw Vol. 66 (2021) | Issue 5 ı September
OPERATION AND NEW BUILD 22
testing methods, procedures, etc.) on
the basis of the findings of the ageing
management programme.
Lesson learned #5 – Ageing
management programmes for specific
degradation mechanisms should
| Fig. 7.
Ageing mechanisms present in the events.
| Fig. 8.
Deficiencies in design versus ageing mechanism.
be developed to avoid or mitigate
accelerated ageing (e.g., flow
accelerated corrosion, fretting, stress
corrosion cracking, thermal ageing).
It is important also to identify
and justify possible associated
| Fig. 9.
Deficiencies in ageing management programmes versus ageing mechanism.
changes in process conditions (e.g.,
flow pattern, velocity, vibration) that
could cause premature ageing and
failure.
Lesson learned #6 – The adequacy
and effectiveness of the inspection
and monitoring methods should
be periodically reviewed to maintain
plant safety and to ensure feedback
and continuous improvements of
ageing management. The evaluation
of technology and methods should
consider the need for detection of
unexpected degradation, depending
on how critical the SSC is to safety.
Lesson learned #7 – Adequate
oversight by the licensee is recommended
during all phases of design,
procurement, testing, receipt inspection
and installation to avoid events
where wrong material is used. When a
wrong or low performance material is
already installed, the rate of material
degradation can often be reduced by
optimizing operating practices and
system parameters.
Lesson learned #8 – Data on
operating experience can be collected
and retained for use as input for the
management of plant ageing. Reviews
of operating experience can identify
areas where ageing management
programmes can be enhanced or new
programmes developed.
Lesson learned #9 – Earlier
detection of degradation is necessary
to ensure timely application of mitigation
strategies. There is the possibility
that such early physical damage (e.g.,
change of locally averaged material
properties) can be detected with
appropriate sensors.
Lesson learned #10 – The operating
organization should ensure
that ageing management programmes
are reviewed on a regular basis and,
if needed, modified to ensure that
they will be effective for managing
ageing. Where necessary, frequently
as a result of reviewing operating
experience, new ageing management
programmes have to be developed.
| Fig. 10.
Number of events per consequence.
| Fig. 11.
Distribution of corrective actions.
Operation and New Build
Operating Experience from Ageing Events Occurred at Nuclear Power Plants ı Antonio Ballesteros Avila and Miguel Peinador Veira
atw Vol. 66 (2021) | Issue 5 ı September
Advertisement
Conclusions
Ageing is a concern for the safe longterm
operation of NPPs. In particular
for the EU nuclear reactors, many of
them being between 31 – 40 years old.
In this respect, operating experience
from ageing events can contribute to
a great extent to enhance nuclear
safety.
The IRS database was screened to
select relevant events related to
ageing, which took place in the period
01.01.2008 – 30.06.2018. In total
113 events were analysed. The
analysis showed that “28 years” represents
the average age of a nuclear
power plant when the event occurred.
Deficiencies in maintenance or surveillance
is the most important root
cause, followed by deficiencies in
design and in ageing management
programmes. Corrosion is the main
degradation mechanism, followed by
fatigue. Other important contributions
are coming from thermal ageing,
wear and electrical ageing. Many
events only appear after long-term
operation of an aged component or
material, and the main cause was a
deficiency in design that was hidden.
110 low level lessons learned
( specific for the events) and 10 high
level lessons learned (generic) have
been obtained in this study. They
cover different areas, such as hidden
deficiencies in design, the impact of
ageing on maintenance and inspection,
deficiencies or lack of ageing
management programmes, use of
wrong material, etc.
This study highlights that the
continuous analysis of ageing related
events and the efficient utilization
of operational experience provides
important insights for improving the
quality of ageing management programmes
and for preventing the
occurrence of unusual events.
ı
ı
ı
ı
ı
IAEA, 2010. IRS Guidelines, Joint IAEA/NEA International
Reporting System for Operating Experience, IAEA Services
Series 19, Vienna.
https://www.iaea.org/publications/8405/irs-guidelines
IAEA, 2014. Approaches to Ageing Management for Nuclear
Power Plants: International Generic Ageing Lessons Learned
(IGALL) Final Report, IAEA-TECDOC-1736, IAEA, Vienna.
IAEA, 2018. Specific Safety Guide No. SSG-48, Ageing
Management and Development of Programme for Long Term
Operation of Nuclear Power Plants, IAEA Safety Standards,
Vienna.
https://www.iaea.org/publications/12240/
ageing-management-and-development-of-a-programme-forlong-term-operation-of-nuclear-power-plants
IAEA, 2020. Ageing Management for Nuclear Power Plants:
International Generic Ageing Lessons Learned (IGALL), Safety
Reports Series No. 82 (Rev. 1), IAEA, Vienna.
https://www.iaea.org/publications/13475/
ageing-management-for-nuclear-power-plants-internationalgeneric-ageing-lessons-learned-igall
JRC, 2021. European Clearinghouse on Operating Experience
Feedback.
https://clearinghouse-oef.jrc.ec.europa.eu/
Author
Antonio
Ballesteros Avila
Scientific Officer
Joint Research Centre of
European Commission,
Petten, The Netherlands
Antonio.Ballesteros-
Avila@ec.europa.eu
Antonio Ballesteros is a Scientific Officer of the Joint
Research Centre of European Commission. He has
extensive experience in the fields of material science,
operating experience of nuclear power plants and
nuclear safety. Strong research professional with a
PhD in radiation embrittlement from the Kurchatov
Institute.
Miguel Peinador Veira
Scientific Officer
Joint Research Centre of
European Commission,
Petten, The Netherlands
Miguel.Peinador-Veira@
ec.europa.eu
Miguel Peinador is a Scientific Officer of the Joint
Research Centre of European Commission. He has
experience in nuclear engineering, nuclear safety and
project management. He is currently leading the
European Clearinghouse on Operating Experi ence
Feedback of the Joint Research Centre (JRC)
12th
International
Symposium
Release of Radioactive
Materials
Provisions for Clearance
and Exemption
The new IAEA Safety
Guide DS500
on the “Application
of the concept of
clearance” is in the
process of endorsement
and will provide
detailed guidance on
the application of the
concept of clearance
for materials.
OPERATION AND NEW BUILD 23
References
In cooperation with
ı
ı
ı
ı
ı
Ballesteros A., Peinador M., Heitsch M., 2015. EU Clearinghouse
Activities on Operating Experience Feedback, BgNS Transactions
volume 20 number 2 (2015) pp. 93–95.
http://bgns-transactions.org/Journals/20-2/vol.20-2_03.pdf
Ballesteros Avila A., 2019. Analysis of ageing related events
occurred in nuclear power plants, Topical Study from the EU
Clearinghouse on Operating Experience, Technical Report by the
Joint Research Centre of the European Commission, JRC119082.
ENSREG, 2018. First Topical Peer Review Report “Ageing
Management”, European Nuclear Safety Regulator’s Group
ENSREG.
http://www.ensreg.eu/eu-topical-peer-review
Euratom Treaty, 2012. Consolidated version of the Treaty
establishing the European Atomic Energy Community.
https://eur-lex.europa.eu/legal-content/EN/TXT/
?uri=CELEX%3A12012A%2FTXT
European Union, 2014. Council Directive 2014/87/Euratom
of 8 July 2014 amending Directive 2009/71/Euratom.
https://eur-lex.europa.eu/legal-content/EN/TXT/
?uri=uriserv%3AOJ.L_.2014.219.01.0042.01.ENG
More information:
www.tuev-nord.de/
tk-rrm
Operation and New Build
Operating Experience from Ageing Events Occurred at Nuclear Power Plants ı Antonio Ballesteros Avila and Miguel Peinador Veira
atw Vol. 66 (2021) | Issue 5 ı September
24
AT A GLANCE
Ultra Safe Nuclear Corporation
Fully Ceramic Microencapsulated Fuel:
Possibilities and Prospect
An Historical Perspective on HTGR Fuel
High temperature gas-cooled reactors were conceptualized in the 1940s in
the U.S. (Daniel’s Pile) and ultimately realized in the 1950s in the UK (Dragon
Reactor). The various performance and safety benefits of these systems
could only be realized if a fuel system capable of retaining radionuclides at
high temperatures (> 1000°C) was possible.
In the late 1950s, the Dragon fuel developers abandoned
the vented fuel pin designs in favor of small spherical
coated fuel particles. Hence was born bi-, and
subsequently, tri-structural isotropic (TRISO) fuel
particles around which many of today’s advanced
reactors are designed. Decades of worldwide research
and development have resulted in a well-codified
basis of knowledge for manufacturing and performance
of the TRISO fuel form that is being leveraged in the
design and licensing of these reactors.
The high-temperature radionuclide retention capability
of TRISO fuel particles, coupled with reactor system
designs that allow passive heat removal during
off- normal conditions, are the basis of modern,
inherently- safe nuclear energy systems. Further
improvement in the radionuclide retention capability
and environmental stability of the fuel increase safety
margins, decreasing the necessary size of the ( Emergency
Planning Zone) EPZ. This is particularly important for
enabling economical distributed energy generation
using micro-reactors that are to be deployed in large
numbers (many hundreds or thousands).
New Possibilities with FCM®
Ultra Safe Nuclear Corporation (USNC) is the leading
developer of high temperature gas-cooled micro reactors
with its flagship Micro Modular Reactor, MMR. Key
to the design of the MMR, is its fully ceramic microencapsulated,
FCM®, fuel that comprises TRISO fuel
particles embedded inside of a refractory silicon carbide
ceramic.
FCM fuel was first conceptualized in 2010 by Ultra Safe
Nuclear Corporation (USNC) founder, Francesco Venneri,
along with scientists at Oak Ridge National Laboratory
(ORNL), and has undergone active research and
development since. USNC’s reactor technology was built
around this revolutionary fuel system and leverages its
immense safety and performance benefits to deliver
highly economic and inherently safe nuclear energy
systems.
The FCM fuel architecture is a major change from the
historic graphitic-matrix fuel forms and offers significant
benefits. The graphitic matrix exhibits complex irradiation
behavior (initially shrinks, then expands) and is only
able to retain its limited initial strength up to low doses.
The silicon carbide matrix, because of its well-known and
finite swelling behavior, is able to withstand very high
irradiation doses while retaining its configuration and its
strength. The graphitic matrix is also readily prone to
oxidation, making it susceptible to degradation in the
presence of trace amounts of air or moisture leaking into
the reactor coolant. The opposite is true for silicon
carbide as it exhibits exceptional air and steam oxidation
resistance.
Finally, and most importantly, the porous, highly
inhomogeneous, and amorphous graphitic matrix does
not form a hermetic barrier to fission product release.
Silicon carbide, on the other hand, is the key constituent
in TRISO fuel responsible for the exceptional fission
At a Glance
Ultra Safe Nuclear Corporation
atw Vol. 66 (2021) | Issue 5 ı September
25
product containment within the fuel particles. When
employed as a matrix surrounding the fuel particles, it
provides a second highly effective barrier to any trace
radionuclide release that may arrive from the particles.
These benefits of FCM fuel represent a major evolution
in what is now possible in advanced nuclear energy
systems such as MMR.
FCM as a Flexible Fuel Architecture
In the past few years, advances in manufacturing
technologies, specifically three-dimensional (3D)
printing, have been applied to the production of silicon
carbide matrix FCM fuel. The use of 3D printing results
in the possibility of geometrically-unconstrained reactor
core designs, offering further improvements in performance
and safety.
FCM fuel, owing to the presence of multiple inherent
barriers to radionuclide release, offers a geologically
stable repository-ready fuel form. These barriers also
increase the difficulty of any attempts at clandestine
recovery of actinides, resulting in increased proliferationresistance.
In addition to the possibility of once-through disposal of
high burnup uranium based FCM fuel, FCM provides an
ideal route for disposition of waste from other reactors
through transmutation of transuranic elements (TRU).
TRU (Np, Pu, Am) from reactor spent fuel may be transformed
into TRISO and FCM fuel and optimally destroyed
(burned) in MMRs. The FCM compacts act both as a
robust fuel form for deep burning and as an ideal waste
form for permanent disposition.
FCM Manufacturing at Scale
AT A GLANCE
The highly robust FCM fuel technology, and the
associated manufacturing methodology, are wholly
agnostic to the overall fuel geometry, type, and configuration
of the coated fuel particles. Therefore, FCM
fuel, as manufactured today, offers a fully flexible
architecture to enable efficient deployment in a range of
core designs and reactor systems. Some of these designs
benefit from other variants of coated particle fuel, such
as uranium nitride TRISO (instead of uranium oxidecarbide)
or BISO particles, that lend themselves to highly
compact or extraterrestrial-power systems.
USNC exclusively owns the intellectual property rights to
FCM fuel and associated silicon carbide 3D printing
technologies, leveraging them for design and deployment
of its various nuclear energy systems that include
and expand beyond MMR.
Repository Ready Fuel System
USNC is actively working on deployment of pilot and
commercial-scale manufacturing facilities for production
of FCM fuel. Two facilities in the United States (Salt Lake
City, UT and Oak Ridge, TN) are currently commissioned
and are undertaking pilot production activities. This
includes deployment and shakedown testing of
production modules for the various serial processing
steps to manufacture FCM fuel and full codification and
qualification of these modules.
USNC’s objective is the widespread deployment of safe,
clean, cost-effective, and reliable nuclear energy for the
benefit of humanity on earth and beyond. FCM fuel
technology is a core component of our value pro position.
We are working relentlessly to deploy large-scale
manufacturing of this highly robust fuel system and
invite partners who share our vision to join us in this
endeavor.
Kurt Terrani
Executive Vice President
Ultra Safe
Nuclear Corporation
USNC shares the vision of dramatically reducing the
radiotoxicity, volume, hazard index, and handling cost of
spent nuclear fuel originated from advanced reactors
and the current fleet of light water reactors. The high
radionuclide retention capability of the silicon carbide
matrix in FCM fuel, reduces radiological contamination
of core materials in advanced reactors. For example, the
large hexagonal graphite blocks in prismatic high
temperature gas-cooled reactors may only be disposed
of as low-level waste when they are fueled with FCM,
greatly reducing the waste volume.
Contact
Ultra Safe Nuclear Corporation
info@usnc.com
www.usnc.com
twitter.com/UltraSafeNuke
linkedin.com/company/usnc
At a Glance
Ultra Safe Nuclear Corporation
atw Vol. 66 (2021) | Issue 5 ı September
26
FUEL
Westinghouse
Fuel Design Advancements
Derek Wenzel, Uffe Bergmann and Juan Casal
The article presents recent advancements of the Westinghouse PWR and BWR fuel products and focuses on new
design features that are targeted to further improve the fuel reliability and performance in the near future.
Introduction PWR fuel
Westinghouse currently supplies fuel
to more than 100 PWR plants
worldwide consisting of 14x14, 15x15,
16x16, and 17x17 Westinghouse
NSSS, Combustion Engineering (CE)
16x16, KWU designs, and VVER fuel
designs. Design improvements have
been completed over the years to
enhance reliability, mitigate fuel
leakers, and address other fuel
related issues such as fuel distortion,
handling damage, and control rod
insertability. Theses advancements
have significantly improved fuel
performance in all PWR designs. As an
example, the con tinued use of the
Westinghouse NSSS design’s multilayer
debris protection with the Debris
Filter Bottom Nozzle (DFBN), Robust
Protective Grid (RPG) and fuel rod
oxide coating has mitigated debris
fretting leakers in the interior of the
fuel assembly. However, there are still
periodic peripheral rod leakers due to
the debris path between assemblies.
To combat the periodic peripheral
rod leakers, Westinghouse has developed
two different types of innovative
Advanced Debris Filter Bottom
Nozzle (ADFBN) designs. The development
of the first ADFBN design
has been deployed in several US
reactors. Through extensive testing,
the ADFBN design has been proven to
significantly reduce the debris leakage
path between assemblies and further
prevent peripheral rod leakers. A
follow up advanced nozzle has been
designed for additive manufacturing
(AM) processing to create complex
debris path traps to dramatically
improve debris filtering capability. The
AM design has shown significant debris
filtering improvement through rigorous
debris test simulations. Westinghouse
has incorporated this additional debris
protection techno logy into part of the
PRIME fuel design, which packages
multiple feature enhancements together
to improve fuel performance
and reliability that also support higher
burnups. These PRIME features are
being delivered in region quantities
beginning in 2021.
PRIME fuel description
The PRIME fuel design is built upon
the overall excellent performance
history of Westinghouse NSSS fleet
including 17x17 OFA, 17x17 RFA/
RFA-2, and 15x15 Upgrade fuel
designs. The PRIME fuel design
incorporates three new hardware
features. The first feature is the transition
from ZIRLO® grids to Low Tin
ZIRLO grids. The second feature is
the use of the reinforced dashpot
| Fig. 1.
Advanced PRIME Features.
design. The third feature is the use of
the PRIME bottom nozzle, which
utilizes the ADFBN side skirt filter
technology and also implements a
lower pressure drop feature. All three
PRIME features are adopted into the
existing skeleton design to further
advance fuel performance while
maintaining fuel reliability.
The PRIME fuel design features
are shown in blue font in Figure 1
below:
Fuel
Westinghouse Fuel Design Advancements ı Derek Wenzel, Uffe Bergmann and Juan Casal
atw Vol. 66 (2021) | Issue 5 ı September
FUEL 27
| Fig. 2.
Tube-in-Tube Dashpot Assembly Design Schematic.
| Fig. 3.
Swaged and External Dashpot Assembly Design Schematics.
Improved grid strap material
Low Tin ZIRLO material has been
chosen as the latest alloy to be used for
Westinghouse grids. This material has
lower tin content as compared to
standard ZIRLO, which provides for
enhanced performance with regard to
corrosion and grid growth. Westinghouse
has successfully implemented
similar Low Tin ZIRLO materials in
fuel rods in many reactors and the
rods have shown significantly reduced
oxide as compared to standard ZIRLO
and Zr-4 rod materials.
Improved skeleton stiffness
Many nuclear utilities have expressed
their interest in high burnup operation
that provides fuel economics
savings through increased cycle
lengths and fewer outages. However,
high burnup operation leads to fuel
performance limitations including
fuel distortion that could result in
incomplete rod insertion (IRI) concerns
as experienced back in the early
1990s in some plants. An IRI event can
occur when the control rodlet cannot
be fully inserted in the guide thimbles
of the fuel assembly due to excessive
drag force between the guide thimble
or dashpot tube inner surface and
control rodlet. Many factors contribute
to an IRI event including
fuel assembly dimensional stability.
Westinghouse has eliminated those
IRI concerns through introduction of
the RFA fuel design with ZIRLO
material, thicker guide thimble walls
and the tube-in-tube design with no
IRI performance issues reported.
To address potential fuel performance
limitations regarding
fuel distortion during high burnup
operation, Westinghouse has implemented
incremental skeleton stiffness
enhancements through development
of the reinforced dashpot design. The
new design provides additional
resistance to distortion in the dashpot
region during high burnup operation.
It is critical to provide higher distortion
resistance in the dashpot area
of the thimble tube since the dashpot
region has minimal clearance between
the control rodlet and the inner
surface of the thimble tube.
Two reinforced dashpot designs
were selected to improve skeleton stiffness
in the dashpot region for the
PRIME fuel package. The first chosen
reinforced dashpot design is the
existing tube-in-tube design, shown
in Figure 2, due to its positive field
experience and availability for fuel
designs ranging from 14, 15, and
17 RFA and 17XL RFA arrays. However,
it has not been universally implemented
across the Westinghouse NSSS
designs. The tube-in-tube dashpot
assembly design consists of a constant
diameter outer thimble assembly and
a separate internal dashpot assembly.
The second chosen reinforced dashpot
design is the external dashpot tube
design shown in Figure 3. The external
dashpot assembly is retro fitted into the
existing 17x17 OFA swaged guide
thimble assembly without any hardware
changes to the fuel assembly
skeleton hardware to minimize additional
changes to the 17x17 OFA fuel
design, which has performed exceptionally
over the years. The external
tube is placed between the bottom grid
and the bottom-most mid grid before
the swaged transition as shown
in Figure 3. The external tube is
mechanically fastened with two
restraint bulges to connect the external
dashpot tube to the guide thimble
tube. The external dashpot design
is exclusively part of the PRIME
17x17 OFA design.
Improved debris filtering
The debris protection features for
Westinghouse NSSS PWR fuel have
provided very good performance
historically with respect to debris
fretting leakers. These multi-layer
debris protection features are
illustrated in Figure 4. The historical
Debris Filter Bottom Nozzle (DFBN)
design had small flow hole sizes and is
designed to mitigate debris-induced
fuel rod fretting leakers by preventing
debris from entering the fuel assembly.
The Robust Protective Grid (RPG)
traps any debris that passes through
the DFBN against the elongated solidfuel-
rod-bottom end plug avoiding
penetration of the clad. Oxide coating
over the bottom six inches of each fuel
rod increases the surface hardness,
thus increasing wear resistance over
uncoated cladding.
| Fig. 4.
Proven Multi-layer Debris Protection Features.
Fuel
Westinghouse Fuel Design Advancements ı Derek Wenzel, Uffe Bergmann and Juan Casal
atw Vol. 66 (2021) | Issue 5 ı September
FUEL 28
PRIME bottom nozzle
The PRIME Bottom Nozzle design is
comprised of an improved top flow
plate and a lower side-skirt so that the
bottom of the skirt is 0.125 inch from
the lower core plate. The lowered
side-skirt avoids any interferences
with lower core plate protrusions
from any Westinghouse NSSS plant
and has demonstrated significant filtering
improvement over traditional
DFBN side-skirts through extensive
flow testing. The PRIME Bottom
Nozzle also been developed to incorporate
an optimized flow hole feature
to provide an added benefit to reduced
pressure drop relative to the existing
| Fig. 6.
Additively Manufactured (AM) Bottom Nozzle.
| Fig. 5.
PRIME Bottom Nozzle Optimized Flow Hole
Features to Reduce Pressure Drop.
| Fig. 7.
Additively Manufactured Bottom Nozzle Top Plate Filter.
DFBN designs. The top plate flow hole
has been optimized to incorporate a
double inlet and single outer chamfer
as shown in Figure 5, which provides
additional thermal-hydraulic performance
margin to the fuel assembly.
Additively manufactured
bottom nozzle
The AM Bottom Nozzle design, shown
in Figure 6, is made from Alloy 718
and utilizes a lowered skirt similar to
that of the PRIME Bottom Nozzle with
a top flow plate that dramatically
reduces the size of debris that can pass
through to the fuel rods. The additive
manufacturing process has the ability
to create high fidelity geometries
with high strength alloys, such as
Alloy 718, to enable the possibility of
creating this complex top flow plate.
Since the AM Bottom Nozzle is
made from a much stronger material
(Alloy 718) than current bottom
nozzles, which are made from stainless
steel, the thickness of the structural
members can be minimized which allows
for more overall flow area
through the top flow plate and reduces
the pressure drop of the structural
portion of the top flow plate. Complex
debris filtering features are added
between the structural members to use
the pressure drop margin to provide
dramatic improvement in top plate
debris filtering – reducing the size of
the debris that can pass through the
top flow plate by a factor greater than
10 and thereby render it harmless. The
specific concept used for the AM
Bottom Nozzle is the double spire (i.e.,
two meshes used), shown in Figure 7.
The two spires (or meshes) are offset
from each other to provide maximum
debris filtering capability. The AM
Bottom Nozzle design is planned to be
deployed in lead use fuel assemblies in
2022. The AM Bottom Nozzle design is
not part of the PRIME fuel design but
is an option to replace the PRIME
Bottom Nozzle to provide further
advanced debris protection.
BWR fuel product development
In the continued strive to offer Fuel
Products with additional value both in
terms of performance and reliability
to the BWR plants, Westinghouse
has pursued the development of the
TRITON11® fuel, a new 11x11-rods
design concept, as well as the new
StrongHold® fuel inlet debris filter to
be used in the Westinghouse SVEA-96
Optima3 and TRITON11 BWR fuel
products.
Given the current economic
pressure on the utilities, the key
| Fig. 8.
TRITON11 fuel design.
development objective of TRITON11
was to significantly reduce the fuel
cycle costs, together with the ability of
meeting the varying requirements
between the different BWR utilities
(such as extended cycle lengths,
power uprates and higher burnups),
while minimizing the risk of fuel leakers.
TRITON11 is the greatest leap in
Westinghouse BWR fuel innovation
since the introduction of the SVEA
concept in the early 1980’s. The
fuel assembly mechanical design for
Nordic ASEA-type reactors is shown in
Figure 8. In total, there are 109 fuel
rods: 91 fuel rods of full length, 10
part-length rods of approximately 1/3
length and 8 part-length rods of
approximately 2/3 length. All fuel
rods are resting freely on the bottom
tie plate and laterally supported by
10 spacer grids of the same sleevetype
design as used in SVEA-96
Optima 3 fuel. Three cylindrical water
channels referred to as water rods
provide non-boiling water for improved
moderation in the interior part
of the fuel bundle.
The TRITON11 fuel assembly
design has been verified by out-of-pile
testing and analyses to fulfill all
requirements for insertion of Lead
Test Assemblies (LTAs) in a nuclear
plant. This includes all mechanical,
thermal-hydraulic, and nuclear design
features as well as the ability to safely
transport the fuel in channeled condition
and the ability to perform
reliable fuel service, inspection, and
repair. The verification scope has been
significantly extended by use of more
advanced testing techniques and
analysis methods to gain further
insight in the behavior of the new
design. All manufacturing processes
for the first LTA deliveries have been
tested, verified, and qualified to meet
the high-quality standards and
efficiency recognized in Westinghouse
Fuel
Westinghouse Fuel Design Advancements ı Derek Wenzel, Uffe Bergmann and Juan Casal
atw Vol. 66 (2021) | Issue 5 ı September
Authors
| Fig. 9.
Visual inspection of the upper part of the TRITON11 assembly.
Derek Wenzel
Manager, Product &
Process Operations
Nuclear Fuel Engineering
and Parts
Westinghouse Electric
Company
Columbia, SC, USA
wenzelds@
westinghouse.com
FUEL 29
Dr Uffe Bergmann
Consulting Engineer
BWR & VVER Fuel
Technologies
Global Technology Office
Westinghouse Electric
Sweden AB
bergmauc@
westinghouse.com
| Fig. 10.
Left: StrongHold debris filter inlet side. Right: StrongHold AM debris filter inlet side.
products. The 18 LTAs, initially loaded
in two Nordic plants in 2019, included
in the in-pile demonstration program
for TRITON11, completed their
second annual cycle of operation in
May 2021. Poolside inspections
performed in both plants after one
and two years of operation, including
visual examination and dimensional
measurements on fuel bundles and
channels, have verified the anticipated
behavior, as exemplified in
Figure 9 for the upper part components.
As a response to the growing
concerns about debris fretting
leakers in BWR fuel, Westinghouse is
launching its new StrongHold debris
filter. The debris capture efficiency
of this new filter design was finely
optimized using a new enhanced
testing methodology. Further improvements
in capture efficiency were
obtained by utilizing the flexibility
of Additive Manufacturing (AM) to
create an extraordinary design
referred to as StrongHold AM. Both
filter designs have been proven to
capture thin metal wires, of any shape,
with 100 % efficiency down to a wire
length of 7 mm - and even lower for
the StrongHold AM filter. The now
completed out-of-pile testing and
verification of both designs included
testing of debris capture efficiency
and post-LOCA clogging, filter pressure
drop and filter mechanical
endurance. The StrongHold filter
showed additional margin, relative to
the previous TripleWave+ filter,
against clogging by the type of debris
that may be released during a LOCA.
StrongHold is based on the same
basic geometry as the TripleWave+
debris filter with a central wavy
obstacle. By introducing additional
perpendicular plates, the flow is split
into narrow square-shaped flow
channels as can be seen in Figure 10.
The version of the StrongHold debris
filter shown in the left panel is conventionally
manufactured by cutting and
stamping metal plates, assembling,
and welding. The more advanced
StrongHold AM version, shown in the
right panel, is built in one piece from
metal powder by use of AM technology.
The added mechanical
strength from the all-internal “welds”
of StrongHold AM filter enables a
reduction of the wall thickness. The
resulting reduction in pressure
drop enables some enhanced design
features that further improve its
capture efficiency for very short wires,
by topology optimization.
Both variants of the StrongHold
filter design will greatly reduce the
risk of debris fretting leakers in future
deliveries of SVEA-96 Optima3 and
TRITON11 fuel assemblies.
Trademarks
PRIME, ZIRLO, Low Tin ZIRLO, TRITON11, SVEA-96 Optima3,
StrongHold and HiFi are trademarks or registered trademarks
of Westinghouse Electric Company LLC, its affiliates and/or its
subsidiaries in the United States of America and may be registered
in other countries throughout the world. All rights reserved.
Unauthorized use is strictly prohibited. Other names may be
trademarks of their respective owners.
Juan J. Casal
Customer Solutions and
Product Manager
Fuel Hardware (BWR)
and Engineering Services
EMEA – Operating Plant
Services
Westinghouse Electric
Sweden AB
casaljj@
westinghouse.com
Fuel
Westinghouse Fuel Design Advancements ı Derek Wenzel, Uffe Bergmann and Juan Casal
atw Vol. 66 (2021) | Issue 5 ı September
FUEL 30
Kazatomprom and the Nuclear Fuel Cycle
Mazhit Sharipov
As it is well known, Kazakhstan has significant natural uranium reserves, ranking second in the world (15 %) after
Australia (28 %). Since 2010, Kazatomprom (the National Uranium Operator) has been the leading producer of natural
uranium (yellowcake) in the world, which has provided Kazakhstan with a 41 % share of global production.
Kazatomprom also seeks to expand its presence in other parts of the global nuclear fuel market.
| “ULBA-FA” LLP fuel assemblies production line.
Kazatomprom is systematically working
to achieve and maintain the status
of a Preferred and Reliable Partner
for the global nuclear industry over
the long-term. At the same time,
attention is paid to compliance
with the principles of Sustainable
Development and ESG (environment,
social responsibility and governance).
Kazatomprom is currently developing
its uranium deposits using
the in-situ recovery (ISR) method,
which is both the most environmentally
friendly and most costeffective
method of uranium mining.
Since 2018, the Company has also
been the global leader in uranium
sales.
NFC projects
Kazatomprom is interested not only in
the extraction and supply of natural
uranium, but also in the production
and sale of more refined uranium
products.
The advantages of the chosen
direction are the development of
technologies for creating uranium
products with higher added value, the
expansion of export potential, the
possibility of offering a complex
product on the global market and the
development of new sales channels.
Uranium processing
Ulba Metallurgical Plant (UMP) with
its long history, technology and
capacity, as well as its qualified
| Area for preparing press powders to be used
for production of fuel pellets.
| Fuel pellets.
engineering and technical personnel,
was appointed as the key uranium
processing enterprise for the development
of the Kazakhstan’s nuclear fuel
cycle.
Currently, UMP is one of the largest
manufacturers of uranium, beryllium
and tantalum products. It has more
than 70 years of experience in the
production and supply of high-tech,
world-class products that are used
in the nuclear, aviation, and space
industries, as well as in electronics,
medicine, instrumentation, science
and many other leading industries.
Today, uranium production at
UMP includes the production of U 3 O 8 ,
uranium dioxide powders from a
variety of raw materials (refining and
| Checking up the diameter of fuel pellets.
| Administrative building of Ulba Metallurgical Plant.
| Fuel pellets sintering area.
Fuel
Kazatomprom and the Nuclear Fuel Cycle ı Mazhit Sharipov
atw Vol. 66 (2021) | Issue 5 ı September
isotopic enrichment products, as
well as fuel fabrication by-products)
and fuel pellets. Uranium products
are certified by and supplied to the
largest fuel producers in the world in
countries throughout North America,
Europe and Asia.
UMP is also mastering the production
of new products and is
carrying out certification processes in
various countries. For the past
10 years, UMP has been manufacturing
and supplying fuel pellets to China
factories and there are also long-term
contracts.
The enterprise seeks to adapt its
products to new requirements and
it is therefore upgrading the pellet
production process.
UMP has completed the re-qualification
of its fuel pellet production
for French designed AFA 3G type fuel
assemblies, and it has polished the
technology for the production of fuel
pellets for other types of westerndesign
fuel assemblies. In the very
near future, it is expected that the processes
used in UMP's technological
line will be certified with the further
setting up the production of new
design fuel pellets and their supply to
new markets.
Participation in uranium
enrichment
Demonstrating adherence to the
principles of nonproliferation and
strictly adhering to the Nonproliferation
Treaty, obligations to the
| Launching Kazakhstan and Russia’s joint
project on uranium enrichment, 2013.
| Enriched uranium cylinder.
IAEA and international agreements
signed by Kazakhstan, Kazatomprom
implemented a project on uranium
enrichment in Russia.
At present, a joint project with the
Russian party is being carried out on
the basis of the world’s largest Russian
uranium enrichment enterprise – the
Ural Electrochemical Combine. Since
2014, the Kazakhstan-Russian joint
venture Uranium Enrichment Center
JSC had access to Russian uranium
enrichment services in the amount of
5 million SWU (separative work units)
per year.
This makes Kazatomprom a participant
in the enrichment market and
provides guaranteed access to one of
the most important stages of the
nuclear fuel cycle, without which it is
impossible to manufacture nuclear
fuel for nuclear power plants.
Plans for a refinery project
As part of the agreements reached
between Kazatomprom and the
Canadian company Cameco Corporation
in 2020, technologies for the
refining and conversion of uranium
were obtained. At some point in
the future, Kazatomprom plans to
implement a project at the UMP site
for the construction of a refinery using
the obtained technology.
It should be noted that the creation
of a refinery, which is a nuclear purity
U 3 O 8 production facility is intended
to minimize the environmental impact
in the region by eliminating the discharge
of liquid waste, the release of
associated gases and to reduce the
consumption of hazardous chemicals
during the processing of natural
uranium concentrate.
During 2020-2021, an assessment
of the technical capacity and economic
feasibility of such a project was
completed, which resulted in positive
conclusions. Currently, Kazatomprom
and UMP are starting to develop
| “Ulba-FA” fuel assemblies plant.
| Fuel assembly.
design documentation for the eventual
construction of a refinery.
In the future, Kazatomprom also
plans to consider the economic
feasibility of establishing a conversion
facility in Kazakhstan.
Nuclear fuel assembly
production project
Since 2015, a joint Kazakhstan-
Chinese project has been underway to
establish a facility for nuclear fuel
assembly production in Kazakhstan.
The goal of the project is to produce
200 tons of certified French design
AFA 3G fuel assemblies (FA) per year
(enriched uranium) for the reactors
operated by CGN in China.
The project is a unique and positive
example of multilateral, mutually
beneficial cooperation in the field of
nuclear energy, since companies from
Kazakhstan, China, France, USA and
Germany took part in the project.
In 2015, joint venture Ulba-FA LLP
was established (the founders: UMP –
51 %, CGNPC-URC – 49 %) for the
creation and further operation of
a nuclear fuel production plant on
the territory of the Republic of
Kazakhstan, to Chinese nuclear power
plants.
During 2015-2020, major efforts
were taken; agreements were
reached and documented between
Kazatomprom and CGNPC-URC on
the main principles and mechanisms
for the project implementation. The
joint venture Ulba-FA LLP received the
FUEL 31
Fuel
Kazatomprom and the Nuclear Fuel Cycle ı Mazhit Sharipov
atw Vol. 66 (2021) | Issue 5 ı September
FUEL 32
| Skeleton production area.
| Fuel assembly.
technology for the production of
FA with the AFA 3G design from
Framatome; the project documentation
on the FA plant was developed;
contracts were signed with the companies
from France, China and the
Republic of Kazakhstan for the
| Ceremony of signing the agreement on establishment of the IAEA LEU Bank.
manufacture of technological equipment,
as well as the issues on the
supply of components and uranium
raw materials required for production
of fuel assemblies are resolved.
At present, the construction of the
fuel assembly facility has come to the
final stage. This means that a unique
enterprise – a plant for the production
of nuclear fuel for nuclear plants – will
soon start operating in Kazakhstan.
Ulba-FA LLP completed all general
construction work and installation of
high-tech equipment; commissioning
of the entire pro duction line was carried
out and training of technical personnel
was organized. The fuel assembly
plant was accepted for operation
in 2020. All the necessary state licenses
(permits) were obtained to carry
out the declared activities in the field
of atomic energy use (nuclear fuel
production). The audit of the quality
management system by the end user
of the plant’s products has been
successfully passed.
Due to the coronavirus pandemic,
the deadline for completing the
qualification carried out jointly with
Framatome has been rescheduled. At
the moment, all work is on schedule
and the first pilot fuel assemblies have
now been manufactured. Commercial
production of fuel assemblies is
expected for the end of 2021, and in
accordance with the long-term
contract, the first deliveries of finished
products will be carried out next year.
Fuel pellets manufactured at
UMP will be used to fabricate fuel
assemblies at Ulba-FA LLP. Their
production was established more
than 10 years ago and certified for
compliance with the requirements of
nuclear fuel buyers and the developer
of the fuel pellet design.
The creation of the front-line
step of the nuclear fuel cycle in
Kazakhstan – the manufacture of
fuel assemblies – will help to realize
Kazatomprom’s longer-term strategic
goal of investing in processing and
other NFC stages to generate longterm
value for the Company. As a
result, a modern and fully automated
production process will be established
at UMP.
Non-proliferation Projects
Kazakhstan is rightfully recognized
as the leader of the non-proliferation
regime and, being a member of
the Treaty on the Non-Proliferation
of Nuclear Weapons (NPT), is actively
working to further expand the
peaceful use of atomic energy for the
benefit of humanity, to strengthen the
nuclear non-proliferation regime, and
to improve the level of international
security.
The IAEA LEU Bank
Kazakhstan, supporting the IAEA initiatives
aimed at strengthening global
nuclear safety, together with the
Agency, imple mented a project to create
a Low Enriched Uranium Bank
(LEU Bank) on its territory, and Kazatomprom
took an active part in the
project.
This project is one of the most
significant multilateral projects in
the field of non-proliferation and of
mass destruction weapons.
The LEU Bank was established
under the auspices of the International
Atomic Energy Agency
(IAEA) to ensure guaranteed supplies
of nuclear fuel to nuclear power plants
of the IAEA member states and is a
storage facility for low enriched
uranium, which is the starting
material for the manufacture of fuel
for nuclear power plants.
The purpose of creating the
LEU Bank is to ensure the efficient
functioning of the international
nuclear fuel market on a permanent
basis, so that states using nuclear
power or considering the possibility of
its inclusion in the structure of of their
energy production have confidence
that they will be able to obtain nuclear
fuel in a guaranteed and predictable
manner.
On August 29, 2017, an official
ceremony of completion of the construction
of the LEU Bank building
was held with the participation of
Fuel
Kazatomprom and the Nuclear Fuel Cycle ı Mazhit Sharipov
atw Vol. 66 (2021) | Issue 5 ı September
| Uranium hexafluoride cylinders.
| IAEA LEU Bank building.
| Supply of low enriched uranium
to the LEU Bank.
the President of the Republic of
Kazakhstan, the Director General of
the IAEA and other officials of foreign
states and international organizations.
In 2019, the delivery of materials
in the amount of 90 tons of low
enriched uranium in the form of
uranium hexafluoride was organized
to supply the LEU Bank, which is
located at the secure UMP site. This
volume does not exceed 10 percent of
the amount of uranium that was previously
stored at UMP as its own
production reserves.
The LEU Bank reached the operating
stage in 2020, with UMP as the
operator providing all conditions for
the safe storage of LEU.
The placement of the IAEA nuclear
material bank at the UMP recognizes
the high level of safety at the plant
that meets the strictest international
criteria, the qualifications and experience
of workers, and the quality
of the enterprise’s performance.
HEU to LEU processing
In 1999, after 25 years of trouble-free
operation in Kazakhstan, the BN-350
fast neutron reactor, which used
highly enriched nuclear fuel, was shut
down.
In addition, research reactors
running on highly enriched fuel
are being operated in Kazakhstan.
Since Kazakhstan is systematically
fol lowing the course of non-proliferation
and nuclear safety, it is taking
measures to reduce fuel enrichment
in order to liquidate the entire available
stock of highly enriched uranium
(HEU).
For these purposes, over the
period of more than 20 years, joint
trilateral projects are being implemented
between Kazakhstan, the
USA and the Russian Federation to
convert HEU to low enriched uranium
(LEU).
Within the framework of this
project, UMP has developed a technology
for the processing of HEU in
various aggregate states and at
different levels of enrichment (to LEU
with an enrichment of less than
19.5 %), and identified a site to
establish a processing facility.
The conversion of HEU to LEU was
successfully completed. Technologies
developed by Kazakhstan specialists
are highly appreciated by experts
from the IAEA and the US Department
of Energy.
The safe shutdown of the BN-350
reactor and the continuation of
the conversion of fuel for research
reactors in Kazakhstan from HEU
to LEU, significantly contributes to
international security and the nonproliferation
of nuclear weapons.
Conclusions
Thanks to the implementation of its
NFC projects, Kazatomprom not only
creates new production facilities, but
also acquires new knowledge and
competencies while improving the
qualifications of its specialists, and
adopting the best practices in the
nuclear field from the world’s leading
companies.
The implementation of multilateral
projects makes it possible to
expand interaction between companies
from different countries, where
working together on a specific project
in real practice allows experts to
exchange knowledge and experience,
which ultimately is a good example of
international cooperation.
Thus, while maintaining its
leadership in uranium mining,
Kazatomprom is working also to
establish new NFC production facilities
in the Republic of Kazakhstan, for
the production of more refined and
more valuable uranium products. This
is expected to allow the company to
strengthen its position in the global
nuclear market over the longer-term,
and expand its presence in other
stages of the nuclear fuel cycle.
Author
Mazhit Sharipov
Chief
Nuclear Fuel Cycle Officer
National Atomic
Company
Kazatomprom JSC
nac@kazatomprom.kz
Mazhit Sharipov graduated from the Obninsk Institute
of Nuclear Power Engineering, Faculty of Nuclear
Power Plants and Installations with a degree in Heat
Power Engineering. He began his career at the
Institute of Nuclear Physics of the Academy of Sciences
of the Kazakh SSR as an engineer of the Operation
Service of the Experimental Reactor Unit. He also held
various positions in the RoK Ministry of Energy and
Mineral Resources, the RoK Ministry of Industry and
New Technologies and the RoK Agency for Atomic
Energy. Currently Mazhit Sharipov is a Chief NFC
Officer at NAC Kazatomprom JSC.
FUEL 33
Fuel
Kazatomprom and the Nuclear Fuel Cycle ı Mazhit Sharipov
atw Vol. 66 (2021) | Issue 5 ı September
34
SITE SPOTLIGHT
Nuclear Expertise for Germany –
Indispensable Even After
the German Nuclear Phase-out
Spotlight on Advanced Nuclear Fuels GmbH (Framatome)
Framatome
For more than 60 years, Framatome’s professionals have
specialised in the design and construction of nuclear
power plants, the supply of steam generator systems,
the design and construction of components and fuel
assemblies, the integration of automation technology
and service for all types of nuclear reactors. Worldwide,
about 14,000 employees work for Framatome and its
subsidiaries, such as ANF.
The site near Hanau is a competence center for spacer
production for Framatome worldwide. ANF, with its
approximately 420 employees, is a wholly-owned
subsidiary of Framatome GmbH (Erlangen). Specialist
departments within the group of companies are
responsible for the development and design of the
fuel assemblies manufactured at ANF. The close
exchange between the divisions ensures the feedback
of experience and the continuous further development
of the products.
Framatome in Germany
Framatome in Germany with its subsidiary ANF bundle –
especially at the Erlangen, Lingen and Karlstein
sites – comprehensive engineering and manufacturing
capacities and are thus important know-how carriers
for German industry.
The company offers knowledge and experience across
the entire nuclear value chain. With its safety-oriented
technologies for several nuclear power plant types and
models (PWR, BWR, VVER, EPR), the competence
network has always made an important contribution
to the global industry.
Employees: > 3,000
Turnover: > 700 M€
Export share: > 85 %
Locations: Erlangen
Lingen
Karlstein
Framatome in Lingen
(Advanced Nuclear Fuels GmbH)
Advanced Nuclear Fuels GmbH (ANF), based in Lingen,
manufactures boiling water reactor and pressurised
water reactor fuel assemblies for the European market.
The site also offers special products, manufacturing
technology and consulting services for fuel element
manufacturers worldwide. In addition to the
plant in Lingen, ANF also has a component production
facility in Karlstein (Main).
In order to be able to manufacture fuel rods and fuel
elements, the Lingen plant needs cladding tubes and
components such as lower and upper tie plates as well
as spacers. These metallic components are manufactured
both in Germany – at the Karlstein plant – and
in Framatome’s international manu facturing network.
At the same time, the Lingen plant supplies uranium
powder and fuel rods to sister companies abroad. This
allows a flexible response to customer requirements
and synergies in research and development can be
exploited.
The Lingen fuel element plant is licensed to process up
to 650 tonnes of uranium per year in the form of fuel
elements. In addition, up to 800 tonnes of uranium per
year of conversion services may be provided. Since the
start of operation in 1979, 38,000 fuel elements with
more than 6.8 million fuel rods have left the Lingen
plant. The last fuel assemblies for the German market
were delivered in December 2020.
As a result of the German phase-out of nuclear power
generation, the site has received orders for the
reconstruction and dismantling of fuel assemblies that
have not yet been used, thus contributing to nuclear
fuel freedom in decommissioned German nuclear
power plants. Special competences in the development
and construction of manufacturing technologies form
another mainstay and ensure high manu facturing
quality and thus safety in nuclear power plants outside
Germany as well. ANF provides training and further
education for experts in radiation protection, fissile
material monitoring and other nuclear technology
personnel. This is knowledge and expertise that will still
be needed in Germany after 2022.
Site Spotlight
Nuclear Expertise for Germany – Indispensable Even After the German Nuclear Phase-out
atw Vol. 66 (2021) | Issue 5 ı September
35
Stefan Möller, employee in the
production of ANF in Lingen, assembling
a 17 x 17 fuel element for a pressurized
water reactor. The fuel rods are
auto matically pushed into the
predefined locations. Such a fuel element
contains approx. 0.5 t of uranium,
which is provided by the customer.
Hermann Grüter, employee of the fuel rod production, checks the surfaces of
the fuel rods as well as for straightness. This manual test is carried out on a
granite block and concludes several upstream test steps, for leaks for example.
SITE SPOTLIGHT
Transformation: a fuel element fabricator expands its portfolio
“We already dealt with the change in the market situation very actively and
consistently more than 10 years ago, especially in Germany,” explains Peter
Reimann, Managing Director of ANF. “Due to the German energy turnaround,
which heralded the end of elec tricity generation through nuclear power, the
pro duction volume for fuel elements declined notice ably. The “second” German
nuclear phase-out in 2011 has led to an approx. 50 per cent decline in the
manufacturing volume for pressurized and boiling water reactors to date,” he
explains further. “We were able to compen sate for this in part by manufacturing
special products,” he adds.
Peter Reimann,
Managing Director of ANF.
Thus, in recent years, the site has been increasingly transformed into a solution
provider for special products – for example, Gadolinium- and Chrome- doped
tablets and technology. The special com pe tences acquired over many years in
the development of technology solutions and in the construction of machines
and plants for fuel element fabrication are now being successfully marketed
and have become a secure pillar in the overall portfolio.
Current and Future Portfolio at the Framatome Site in Lingen
Development of industrial
Innovations
p
We continuously and sustainably
develop innovations
in manu facturing, technology
and processes and create an
innovation portfolio.
Production of top technologies and
provision of services
p
p
p
Sale of important high-end systems
for fuel element production, individually
adapted to customer requirements.
Complete after-sales services for plants.
New: Production and maintenance of transport
containers on behalf of the Framatome.
Manufacture of fuel products
p
p
p
The production of fuel elements continues
to be our core business and will continue to be
the main revenue driver in the coming years.
We are flexible and build different designs on a
very high, inter nationally recognized quality level.
New: We are expanding our range with an
Eastern European design, so we follow an EU
competition recommendation.
Site Spotlight
Nuclear Expertise for Germany – Indispensable Even After the German Nuclear Phase-out
atw Vol. 66 (2021) | Issue 5 ı September
SITE SPOTLIGHT
36
Before welding the end plug, a spring is inserted into the fuel rod.
This ensures a stable tablet column during production,
but also during transport of the fuel elements to the customer.
Ralf Krüssel, project engineer,
is part of the team
that successfully developed APIS.
Successful examples for special mechanical engineering
Welding systems
The welding systems developed at ANF using the
resistance pressure welding process are set up and
commissioned on site. The welding technology ensures
gas-tight fuel rods – and thus contributes to the safe
use of fuel elements in reactor operation. Behind this
are 50 years of experience and constant further
development of the technology. Welding systems
from Lingen are part of Framatome’s portfolio and are
used in fuel assembly fabrication worldwide.
Testing facilities
The development of the APIS (Automatic Pellet
Inspection System) by ANF Lingen dates back to the
1980s. Since that time, research has been carried out
on the automatic measurement of pellets and the
completion of a suitable system has been advanced.
After many trials and with a higher computer capacity
required for the measurements, it was then possible
in 2007 to qualify and use the first fully automatic
pellet inspection system. With this, all pellets (100 %
inspection) are inspected for various characteristics
automatically, at high speed and with objective
criteria, evaluated and sorted out if necessary. The
APIS as part of the pellet grinding line will also be used
as best practice in Framatome’s sister plant Romans in
the future. The system ensures quality and economic
efficiency. It also reduces the strain on employees at
the workplace. In the meantime, there is already a
further development, which is currently being set up
at the Framatome site in Romans.
“We are proud of the development of our technology
division, but it can only be operated and further
developed in the long term with a functioning fuel
assembly production,” explains Lingen site’s manager
Andreas Hoff. “Only with this can special machines
tested in our own production be marketed in the
longer term,” he adds. Hoff explains: “To compensate
for the declining volumes in fuel assembly production,
we produce special products in the pellet and rod area,
which make a major contribution to the economic
operation of the plant.”
In addition to technology and special machines, the
site markets its know-how worldwide through training
and education, service, consulting and expertise. ANF
experts sit on committees and working groups in the
nuclear industry and are sought-after contacts for
international bodies such as the International Atomic
Energy Agency (IAEA) and the European Safeguards
Research and Development Association (ESARDA).
For Peter Reimann, one thing is certain:
“Framatome GmbH and Advanced Nuclear
Fuels GmbH want to continue to support
the Federal Government in achieving the
goals of maintaining nuclear com petence
and contribute to ensuring that Germany
remains internationally recognized in the
field of nuclear technology.”
Site Spotlight
Nuclear Expertise for Germany – Indispensable Even After the German Nuclear Phase-out
atw Vol. 66 (2021) | Issue 5 ı September
37
Site manager Andreas Hoff at the
Lingen plant with a PWR fuel
element. In the background you
can see the underfloor storage
facility where fuel assemblies are
stored suspended before they are
transported on to the customer.
SITE SPOTLIGHT
Nuclear know-how in demand worldwide
For many countries, nuclear power generation is and will remain an essential part of the national climate
strategy for the coming decades. In Germany too, expertise is still needed for nuclear dismantling, interim
and final storage, but also on issues of national and international safety.
Framatome’s experience feedback in Germany from international projects with various reactor types from
different manufacturers in its current value-added depth complements the decades of experience and
broad expertise, and makes a significant contribution to reconciling national safety requirements and the
safe further development of nuclear energy.
The competences of Framatome GmbH and Advanced Nuclear Fuels GmbH contribute significantly to these
goals:
p
p
Retention of know-how and personnel: Only participation in international projects can ensure exchange
with international partners and thus feedback into training and teaching.
Maintaining competence for activities that are still pending in Germany: Participation in international
projects ensures that nuclear know-how continues to be available in Germany – an essential prerequisite
for maintaining competence for the upcoming challenges such as dismantling, final storage and safety
research in Germany.
p Maintaining a central role in international bodies: By participating in international projects, nuclear,
safety-relevant competences are maintained and expanded. In this way, the Federal Republic of
Germany continues to secure its position as a competent partner in the field of nuclear technology in
international organizations such as the UN, IAEA, OECD, EU and in standards bodies. It can thus continue
to ensure its influence in the future so that globally binding safety standards are met and nuclear
technology is used for the benefit of all.
p
p
Information about developments: Through its involvement in global value chains, the Federal Republic
can gain early access to information and knowledge about developments, projects, planning and
regulations. Without Germany’s active participation in the international nuclear industry, this
knowledge would not be available.
Fuel optimization: The development of fuel elements with high utilization as well as the conversion and
recovery of raw materials from unirradiated products will minimize the amount of used fuel elements
in Germany and worldwide.
Site Spotlight
Nuclear Expertise for Germany – Indispensable Even After the German Nuclear Phase-out
atw Vol. 66 (2021) | Issue 5 ı September
SITE SPOTLIGHT
38
Employees
Urenco-Group approx. 1600
Urenco Deutschland GmbH approx. 300
Turnover
Urenco-Group (2020) > 1700 m€
Urenco Deutschland GmbH (2020) > 400 m€
Nuclear Competencies in Germany –
a Legitimate Case Also After the Nuclear
Phase-out
Spotlight on Urenco Deutschland GmbH
Urenco – enrichment services and
fuel cycle products.
For more than 50 years, Urenco has offered its global
customers safe, cost-effective and reliable uranium
enrichment services based on centrifuge technology
developed in-house. It is the only supplier in the world
to operate enrichment facilities in several countries
simultaneously: the Netherlands (Almelo, since
1973), the United Kingdom (Capenhurst, since 1973),
Germany (since 1985) and the United States (Eunice,
NM, since 2010). Thus, as a supplier to 50 utilities in
21 countries, Urenco contributes significantly to a safe
and low-carbon electricity supply in many countries
around the world.
Centrifuge technology is also used in the Urenco
Group to separate other isotopes. These isotopes are
used, for example, in research or medicine. Last year,
operations began at the Tails Management Facility
(TMF) in Capenhurst. This enables responsible and
resource-conscious handling of depleted uranium.
In addition, Urenco is involved in the development of
U-Battery, an advanced modular reactor.
Site Spotlight
Nuclear Competencies in Germany – a Legitimate Case Also After the Nuclear Phase-out
atw Vol. 66 (2021) | Issue 5 ı September
39
Tails yard
SITE SPOTLIGHT
Urenco Deutschland GmbH – Developments at the site
At the end of the 1970s, the course was set for the location
of Germany‘s first and only uranium enrichment
plant at the Gronau site. The seismically inactive area and
the proximity to the already existing Dutch site were
some of the reasons for the location. The German
production team first gained experience in the Netherlands
before the plant in Gronau in the Münsterland area
went into operation in August 1985 after a successful
licensing and construction process. Since then, Urenco
Germany has produced about 67,000 tones of enriched
uranium.
The nuclear fuel produced from this work has generated
and continues to generate economically about
5.8 trillion kWh of electricity in nuclear reactors, about
10 times the electricity consumption of the whole of
Germany for the year 2019.
A lot happened since the late 1970s, when the site was
purchased, and August 1985, when the first cascades
went into operation. An important development step
happened on Valentine‘s Day 2005, when permission
was granted to expand the plant. At that time, the
responsible authorities in Düsseldorf and Berlin were
both led by a red-green government. The construction
of the uranium separation plant 2, or UTA-2 for short,
then took place. Finally, in autumn 2011, the last
cascades were put into operation and the total
capacity of the plant was increased towards the
approved 4,500 t of separative work per year. As the
last part of the expansion permit, the commissioning
of the structurally complete uranium oxide storage
facility is pending.
For the Federal Republic of Germany,
Walter Scheel and Hans Leussink signed as
responsible Federal Minister/Vice Chancellor
At the beginning of 2017, Urenco‘s Central Technology
Group (CTG) moved from Bad Bentheim (Lower
Saxony) to the Gronau site. Since then, the jointly used
76 ha site has been called the “Gronau Technology
Centre”. This name is all the more appropriate since
“Urenco Technology & Development” (UTD) evolved
from CTG in 2021. UTD consists of highly qualified
employees from all Urenco countries who work and
provide services for the entire group from its main site
in Gronau.
Urenco Deutschland GmbH –
Treaty commitments and oversight
In 1970, the signing of the Treaty of Almelo (NL) marked
the beginning of a hitherto unique international
cooperation in the field of uranium enrichment. Great
Britain, the Netherlands and Germany agreed to jointly
develop centrifuge technology and to use the nuclear
fuel produced exclusively for the peaceful use of nuclear
energy. Nonproliferation has been an important topic
from the very start. With this state anchoring, the
success story of Urenco began.
Over time, this international framework has been
extended. The Washington (1992) and Cardiff (2006)
treaties allow the sharing of technology with French
companies and the construction of a new plant in the
USA. In addition to the multi-state supervision via the
so-called Joint Committee, there are regular controls
by international institutions such as the International
Atomic Energy Agency (IAEA) or the European Atomic
Energy Community (Euratom). There other links with
the IAEA too. For years, Urenco Deutschland GmbH
has supported the IAEA in the training of future
inspectors; and in 2020, the sponsorship of the Marie
Sklodowska-Curie Fellowship Programme by Urenco
was announced by CEO Boris Schucht during an
appointment with IAEA Director General Rafael Grossi.
In addition, ETC Germany, as a subsidiary of Urenco, is
engaged on behalf of the German government with
specialist knowledge and unique expertise in the field
of nuclear nonproliferation and supports the IAEA.
Site Spotlight
Nuclear Competencies in Germany – a Legitimate Case Also After the Nuclear Phase-out
atw Vol. 66 (2021) | Issue 5 ı September
40
SITE SPOTLIGHT
The enrichment process
Cylinder handling UTA-2
Central control room
To initiate and sustain a controlled chain reaction in
natural water, uranium fuel must have a concentration
of U-235 greater than 3 %. Naturally occurring uranium
has a concentration of 0.711 % U-235. The actual
principle of enrichment is simple. By means of rapidly
rotating rotors inside rigid recipients, the difference in
mass between different uranium isotopes can be used
to initiate a separation process and increase the
concentration from 0.711 to about 3-5% U-235 for the
use of nuclear energy for power supply. What makes
this process so challenging and special can be described
as follows:
The cylinders
Roughly speaking, there are two standardised pressure
vessel types that are used to transport the uranium
with its accompanying fluorine (uranium hexafluoride
or UF 6 ). The 30B cylinders are about 2.20 metres long
and hold about 2.2 tonnes of UF6. In total, a cylinder
weighs 2.85 t. The larger 48Y cylinders with a length of
about 3.8 metres weigh about 15 t with UF 6 . As a rule,
the natural uranium and the depleted uranium are
delivered or transported in the 48Y cylinders. In
addition to road transport, the company‘s own railway
siding can also be used for this purpose. The smaller
30B containers are used to transport the final product
according to customer requirements. The manufacturers
of the containers and the production itself
are highly qualified. The cylinders are periodically
inspected and subjected to several tests in accordance
with hazardous goods legislation. These include a
28 bar pressure test, a drop test on an unyielding steel
plate and a fire test (48Y and 30B containers). In
addition, the tanks are made of thick-walled steel (13
or 16 mm) and are visually inspected every quarter in
the storage yard. In the almost four decades of
Urenco‘s operation, there has not been a single
incident or even sign of leakage from a cylinder.
When transporting both the 30B and 48Y cylinders,
protective packaging is also used to protect the
material and the cylinder against, for example, a
theoretical fully contained fire.
The process
For the real procedural process of uranium enrichment,
solid UF 6 (feed) is delivered by truck or rail. Both the
cylinders and the equipment provided are inspected
for possible external contamination and damage as
well as for their suitability. To check the uranium
content, the containers are transported to the separation
plant by a special transport vehicle, where they
are weighed and sampled.
In the plant built until 1998 (UTA-1), the UF6 is fed from
the transport containers by means of a heating station.
In this station, the feed containers are heated to
80 to 100 °C by electrically heated warm air, whereby
their contents liquefy completely. The vapour pressure
created above the liquid phase is fed to the centrifuges
after a multi-stage pressure reduction. After enrichment
in the centrifuges, the UF 6 is fed into deep- frozen
collection containers (desublimors). Here it is frozen
out of the gas phase at -70 °C (desublimated). Water is
used as a coolant for tails and air for product. The filled
desublimors are heated and the evaporating UF 6 flows
in gaseous form through pipes into the transport
cylinders, where it solidifies again through cooling.
In all plant sections built since 1998, feed is supplied
directly from the solid UF 6 phase under athmosphere
pressure. UF 6 pumps are used, which have a much
smaller UF 6 inventory and lower energy consumption
compared to the process described above. Also, in
contrast to the desublimors, much smaller quantities
of refrigerant are required. Product and tails are
desublimated directly with low-pressure pumps into
deep-frozen UF6 transport and storage containers.
There are physical limits to desublimation in a single
centrifuge. No further enrichment or depletion takes
place beyond a certain stage. In the centrifuge process,
the solution is to interconnect several centrifuges
to form so-called cascades. The UF 6 gas is separated
in cascaded centrifuges into an enriched stream
( product) and a depleted stream (tails) (see figure). In
the product transfer system in the technical infrastructure
building, product material of different U-235
concentrations is mixed in order to set the exact
concentration required by the customer for each
container. In the process, the UF 6 is homogenised
(mixed) by reheating and liquefaction. Finally, samples
are taken to determine the degree of enrichment,
before the containers filled with tails or product are
transported to the respective warehouses.
Site Spotlight
Nuclear Competencies in Germany – a Legitimate Case Also After the Nuclear Phase-out
atw Vol. 66 (2021) | Issue 5 ı September
41
Dr. Joachim Ohnemus
Urenco – Outlook for the future.
SITE SPOTLIGHT
Managing Director Dr Joachim Ohnemus sees Urenco
Germany well positioned for the future: „We benefit
from our German mentality. People in the group know
about German virtues. Guests, for example, are often
amazed at the condition of our first plant, which is
already 36 years old. The great effort when it comes
to maintenance measures, ageing management,
redundant design and normal cleaning services is
simply visible in the plant and on its components. In addition,
the installed centrifuges are proving to be very
durable. The cascades from the 1980s and 1990s are
still in operation and generating output. More over, we
are the only European plant to have installed the most
modern centrifuges in our new plant, UTA-2. Only our
US colleagues also use the TC-21. This makes us very
proud, of course, and ensures a balanced plant structure
with tried-and-tested technology that has proven its
efficiency for decades, and with the world‘s most
modern centrifuges and corresponding infrastructure
that has virtually ushered in a new generation.
Nevertheless, we must not rest on our laurels. As the
Urenco Group, we have launched various diversifi cation
projects in order to be able to respond to changing
customer requirements. At our site, Urenco Technology
& Development (UTD) is a sign of our further internationalisation
and the efficiency improvements of the
entire Urenco Group.
I am proud to have been able to follow the path of
Urenco Deutschland as Managing Director for 23 years.
At the end of my career, I am now looking forward to
the 2021 parliamentary elections before I hand over
the baton to my successor, Dr Jörg Harren. Not only can
he look forward to a healthy company in terms of
numbers, but above all to a very committed, wellcoordinated
and highly qualified workforce.“
Sustainability and Net Zero
Sustainability is integral to
everything we do and in 2021
we have refreshed our sustain ability strategy, which is now focused
on three building blocks: environmental impact; social impact and
governance and ethics.
This followed a materiality assessment, gathering the views of key
stakeholder groups through interviews with industry and sustainability
experts, a customer survey, and an employee survey and workshops.
All stakeholders were asked to identify priorities for Urenco from a
comprehensive list of sustainability topics. We took this feedback and
considered the key role that Urenco plays in facilitating the low carbon
energy that society needs; how we conduct our day-to-day activities
with minimal impact to the environment and the communities in which
we operate; and the strategic goals for our long term success.
The resulting refreshed sustainability strategy demonstrates how
Urenco contributes to a net zero world and the United Nations
Sustainable Development Goals (SDGs), and aligns with established
environmental, social and governance (ESG) frameworks.
We are currently working on defining new key performance indicators
and our roadmap to net zero by or in advance of 2040 as part of our
commitment to The Climate Pledge. The roadmap will focus on the
areas of ‘eliminate and reduce’, ‘substitute’ and ‘offset’ and this will be
finalised and communicated later this year.
U-Battery
U-Battery, a micro-modular reactor development programme
involving Urenco, progressed through to the next stage of the
UK Department of Business, Energy and Industrial Strategy’s
(BEIS) Advanced Modular Reactor (AMR) competition last year.
This saw a further £10m contribution from the UK Government
to conduct design and development work to bring the new
nuclear technology closer to market.
It follows the successful completion of a feasibility study that
made the business, economic and technical case for the
deployment of U-Battery in the UK and in Canada, where it
would be deployed in industrial applications, mining sites and
remote locations and have a positive effect on decarbonisation
and climate change efforts. It is also a highly versatile technology
that can be used for other beneficial purposes, such as the
production of hydrogen through the copper chlorine process.
U-Battery received an additional £1.1m of funding from BEIS to
design and build the two main vessels (the reactor and intermediate
heat exchanger) and the connecting duct. During the
next phases of the programme, U-Battery will be working to form
new partnerships for the longer term development of the AMR.
Site Spotlight
Nuclear Competencies in Germany – a Legitimate Case Also After the Nuclear Phase-out
atw Vol. 66 (2021) | Issue 5 ı September
42
DECOMMISSIONING AND WASTE MANAGEMENT
SSiC Nuclear Waste Canisters:
Stability Considerations During Static
and Dynamic Impact
Yanan Zhao, Heinz Konietzky, Juergen Knorr and Albert Kerber
Introduction High-level radioactive waste (HLW) is mainly a by-product of technical nuclear reactions. It has the
highest radioactivity and longest decay time (millions of years with significant radiation). Most HLW (more than 90 %)
comes from spent nuclear fuel. The deep geological disposal concept is considered without alternatives worldwide.
This concept includes the multibarrier
concept, which contains three
main elements:
p Canisters: HLW is sealed safely in
special long-term safe canisters.
p Engineering barrier: Canisters are
embedded into an engineered
sealing environment (e.g. bentonite)
inside the host rock.
p Geological barrier: Embedded
canisters are safely buried underground
protected by geological
layers.
This concept should work for
extremely long time (> 1 Mio. years),
so that any critical contact between
waste and biosphere is avoided.
Two concepts for canisters exist:
corrosion resistant ones and corrosion
allowed ones. Corrosion resistance
considers attack from water, acid,
alkali, salt, radiation, bacteria etc. for
a very long time (e.g. resistance
> 100,000 years). Allowed corrosion
means limited corrosion is accepted
and safety is guaranteed only for a
certain restricted time span (e.g.
about 1,000 years). The central point
is to choose most corrosion resistant
material while meeting also other
criteria. Different countries have
developed different philosophies in
terms of canister design. So far, the
following materials for canisters and
over-packs, respectively, are under
consideration: stainless steel/carbon
steel, nickel alloy, cast iron, pure
copper or copper coating, special
concretes, aluminum, SiC, ZrC,
ceramic coatings.
All the above-mentioned materials
and corresponding canister concepts
have their pros and cons. For nearly all
of them it is critical to proof extreme
long lifetime. In terms of resistance
and lifetime SiC and SSiC especially,
show some remarkable advantages.
Already Onofrei et al. [1] studied
the leaching characteristics of ceramic
canisters. Haslam et al. [2] evaluated
corrosion resistance of ceramic
coatings thermally sprayed on waste
containers in simulated ground water
of 90 °C. Donald et al. [3] estimated
the lifetime of SiC and ZrC coatings
for nuclear fuel in TRISO and TRIZO
concept for direct geological disposal.
Kerber and Knorr [4] proposed a
new concept by SSiC (solid-state
pressure-less sintered silicon carbide)
encapsulation of HLW. This concept
has drawn attention due to the
excellent corrosion resistance, low
permeability and high mechanical
strength of SSiC (see Table 1).
On the other side, SSiC is a brittle
material. Therefore, it is necessary to
consider the stability and potential
fracturing of SSiC canisters under
static and dynamic loading scenarios.
This paper considers this problem via
numerical simulations concentrating
Inert gas, reducing atmosphere Stable up to 2,320 °C
Oxidizing atmosphere
Hydrogen
Water vapor
Acids, diluted and concentrated
H 3 PO 4
HF/HNO 3
Potassium hydroxide solution
Molten sodium and
potassium-hydroxides
on tensile failure (mode-I crack
propagation in terms of fracture
mechanics). Unprotected and protected
(coated, covered) canisters are
investigated. It is not the aim of
this study to deliver comprehensive
simulations for final canister design,
but to provide the order of magnitude
of potentially induced impact stresses
for different loading scenarios and to
document, that proper cover ( coating)
of SSiC canisters can avoid any kind of
mechanical damage during transport,
installation and final storage.
Lab testing and numerical
calibration of SSiC
Special lab tests like illustrated in
Figure 1 were conducted to determine
the tensile strength of the SSiC.
Resistant up to 1.650 °C, above 1,000 °C
formation of protective layer of silica
Stable < 1,430 °C, > 1,430 °C appreciable attack
Stable < 1,150 °C, > 1,150 °C some reaction
Resistant at RT and elevated temperatures
Some attack
Appreciable attack
Appreciable attack
Appreciable attack > 500 °C
Fused sodium carbonate Appreciable attack > 900 °C
Sintered Density > 3.10 g/cm 3
Young’s Modulus
| Tab. 1.
Parameter of SSiC.
400 GPa
Poisson Ratio 0.16
Vickers Hardness HV200
25.7 GPa
Fracture Toughness (indentation with 10 N load) 4.9 MPa m 1/2
Thermal Conductivity
Strength (4-point-flexural test)
120 W/mK
400 MPa
Coefficient of Linear Thermal Expansion at RT 3.3 x 10 -6 K -1
Porosity 1 % – 2 %
Specific Electrical Resistance (depending on impurity level SiC)
Maximal Pore Size
Maximal Crystal Size
10 2 – 10 4 Ωcm
20 – 50 µm
35 µm
Decommissioning and Waste Management
SSiC Nuclear Waste Canisters: Stability Considerations During Static and Dynamic Impact ı Yanan Zhao, Heinz Konietzky, Juergen Knorr and Albert Kerber
atw Vol. 66 (2021) | Issue 5 ı September
Bulk modulus (GPa) 200
| Fig. 1.
Numerical simulation and lab tests of small hollow SSiC cylinders; Numerical model duplicating the lab
tests with indication of tensile failure development at peak pressure; Load-displacement curves of lab
tests and numerical simulation results assuming tensile strength of 150 and 200 MPa, respectively.
This type of test was chosen due to the
following reasons: (a) the extremely
high strength of the material would
make classical tensile tests complicated
and (2) this type of tests
duplicates very well the real canister
situation as hollow cylinder. The
tested cylinders are 5 cm in length and
have outer and inner radius of 2.5 cm
and 2.0 cm, respectively. The small
hollow SSiC cylinders were compressed
between 2 loading platens
until tensile failure initiated at the
inner cylinder wall leads to brittle
failure. In total five lab tests were
conducted, results are presented in
Figure 1. For a hollow cylinder under
compressive line loading the following
analytical solution developed by
Timoshenko exist for the failure load:
(1)
where:
ρ – ratio of inner to outer radius
of cylinder
R – outer radius of cylinder
P – tensile failure load
σ θ – tensile strength
θ – angle.
After conducting the lab tests, equivalent
numerical simulations were
performed (see Figure 1). A modified
elasto-plastic Mohr-Coulomb failure
criterion with tension-cut-off and
strain- softening was applied. To
duplicate the extreme brittle behavior,
after reaching the tensile strength,
softening starts immediately and
tensile strength is set to zero. The
cohesion was deduced from a test
with similar material (SiC-N) and set
to 4 GPa [5]. Tab. 2 shows the used
Shear modulus (GPa) 180
Friction angle (°) 40
Tensile strength (MPa) 150 / 200
Density (kg/m 3 ) 3100
Cohesion (GPa) 4
Dilation (°) 0
Elastic modulus (GPa) 415
Poison’s ratio µ 0.15
| Tab. 2.
Numerical model parameters for SSiC.
| Fig. 2.
Analytical and numerical simulation results for failure load P with varied
radius ratio ρ assuming tensile strength of 150 MPa.
model parameters. The distinct
element code 3DEC [6] was used for
the simulations.
According to Figure 1, the tensile
strength of SSiC is somewhere
between 150 MPa and 200 MPa. For
safety reasons, the tensile strength of
SSiC is set to 150 MPa in all further
calculations. According to Eq. (1) the
failure line load P is determined by
tensile strength σ θ , outer radius R,
as well as radius ratio ρ (ρ = r/R).
Figure 2 compares numerical and
analytical results for failure load P for
different radius ratios and proves that
numerical simulations deliver reliable
results.
DECOMMISSIONING AND WASTE MANAGEMENT 43
Simulation strategy
to consider static and
dynamic loading
Different loading scenarios are considered
under conservative assumptions.
Dynamic loading (impact) is
considered for scenarios during transport
and installation of the canisters.
Static loading via in-situ rock stresses
is considered after final placement of
the canister. Dynamic loading scenarios
comprise two cases: (a) free fall of
a canister and (b) rockfall from
the roof on the canister. In both cases
the considered maximum drop
height is 2 m. In case of static loading
the maximum disposal depth is
Decommissioning and Waste Management
SSiC Nuclear Waste Canisters: Stability Considerations During Static and Dynamic Impact ı Yanan Zhao, Heinz Konietzky, Juergen Knorr and Albert Kerber
atw Vol. 66 (2021) | Issue 5 ı September
DECOMMISSIONING AND WASTE MANAGEMENT 44
Material
Bulk modulus
(GPa)
Shear modulus
(GPa)
Density
(kg·m -3 )
Elastic modulus
(GPa)
1200 meters below surface with
different anisotropic stress ratios
(minimum to maximum principal
stresses) up to 1:3. SSiC canister and
foundation are modelled as elastic
material. The falling rock blocks are
simulated either as elastic material or
as assembly of distinct blocks with
calibrated elasto-plastic parameters,
which allows to consider the rock
disintegration during the impact.
Damping was not applied for the
dynamic simulations because data are
not available, but viscous boundary
conditions were applied to avoid
unrealistic reflections at the lower
bottom of the ground. This makes the
simulations once again conservative.
The interface stiffnesses at the contact
between the colliding parts (e.g.
between canister and rock block or
ground) are adjusted in such a way,
that impact induced stresses reach
maximum values (corresponding lab
data are not available). So far not
explicitly otherwise mentioned the
model parameters given in Table 3 are
applied.
µ jkn
(GPa·m -1 )
jks
(GPa·m -1 )
Rock & Foundation 40 29 2500 70 0.21 100 100
Buffer 1 0.5 2000 1.35 0.27 100 100
SSiC 200 180 3100 415 0.15 100 100
Clay-stone 40 18 2500 47 0.30 100 100
Clay-stone
jkn
TPa·m -1
75
| Tab. 3.
Matrix and interface contact parameters.
jks
TPa·m -1
25
jcoh
MPa
40
jtens
MPa
10
jfric
°
0
res_jcoh
MPa
0
jkn = jks = 440 TPa·m -1 for dynamic loading to avoid unrealistic penetration
| Fig. 3.
Left: Cross section of cylindrical canisters (see also Table 4); middle: Model set-up for canister completely
imbedded inside the host rock incl. buffer; right: Impact constellations of canisters after free fall.
Canister a/mm b/mm c/mm d/mm e/mm f/mm
HTR (5 pebbles) 62 305 92 335 15 15
CANDU 102 510 142 550 20 20
PWR/BWR 400 4930 470 5000 35 35
Vitrified waste 450 1350 500 1400 25 25
| Tab. 4.
Dimensions of canisters (see also Figure 3).
| Fig. 4.
Maximum tensile stress inside unprotected canister for different inclination
angles of VW (up) and HTR (middle) canister (see Table 5).
res_jtens
MPa
0
res_jfric
°
27
Four different canister types are
considered as given by Figure 3 (left)
and Table 4. The considered waste
canisters are hollow cylinders sealed
at one, respectively the two ends using
the technique of Rapid Sinter Bonding
(RSB) as proposed by Knorr and
Kerber [7].
Static loading scenarios
This loading case considers anisotropic
earth pressure on completely in
a rock mass embedded VW and HTR
canisters (Figure 3 (middle)). Table 5
lists all the considered earth pressure
constellations in terms of principal
stresses (X and Y (both horizontal)
and Z (vertical): 1:1:1, 2:1:1, 3:1:1,
2:2:1, 3:2:1, 3:3:1. These constellations
cover all typical stress states
existing in potential host rocks. The
considered maximum principal stress
ratio is 3:1. The angle between canister
axis and Z-axis is set to 0 °, 30 °,
60 ° and 90 °, respectively. Figure 4
documents the maximum induced
tensile stresses inside the SSiC canisters.
The considered depth is 1200 m,
and the vertical earth pressure will
be about 30 MPa. Overall, in any
case the maximum tensile stress in
the unprotected canister does not
exceed 50 MPa which is significantly
below the tensile strength of SSiC,
which is 150 MPa. Maximum tensile
stress is mainly distributed around
the two lids of the canister as shown
in Figure 5. The average stress in
the VW canister is bigger than that
in the HTR canister. The thickness of
the canister is a controlling factor.
For the VW canister, the thickness/
height ratio is 1/56, while the thickness/height
ratio for the HTR canister
is 1/22.
Exemplary, for the HTR canister
some selected simulations with a
buffer sealing (200 mm thick) were
performed. As Figure 6 documents,
such a clay (bentonite) buffer can
significantly reduce maximum tensile
stresses.
Decommissioning and Waste Management
SSiC Nuclear Waste Canisters: Stability Considerations During Static and Dynamic Impact ı Yanan Zhao, Heinz Konietzky, Juergen Knorr and Albert Kerber
atw Vol. 66 (2021) | Issue 5 ı September
| Fig. 5.
Maximum tensile stress [kPa] distribution for unprotected canister,
left: VW canister, rock stresses X: 30 MPa, Y: 10 MPa, Z: 10 MPa, inclination
angle 0 °; right: HTR canister, rock stresses X: 30 MP, Y: 30 MPa, Z:10 MPa,
inclination angle 30 °.
Loading case X/MPa Y/MPa Z/MPa (X/Z)
Case 1 10 10 10 1
Case 2 20 10 10 2
Case 3 30 10 10 3
Case 4 20 20 10 2
Case 5 30 20 10 3
Case 6 30 30 10 3
| Tab. 5.
Primary stresses (see Figures 5 and 6).
| Fig. 6.
Maximum tensile stress of unprotected HTR canister and buffer-sealed
canister for canister inclination angle of 0 ° and 30 ° (buffer thickness
200 mm).
DECOMMISSIONING AND WASTE MANAGEMENT 45
| Fig. 8.
Top: maximum tensile stress at impact [kPa];
Bottom: canister with deformed cover during the collision.
| Fig. 7.
Maximum tensile stress of unprotected canisters versus drop height.
Dynamic loading scenarios
Free fall of canister
For impact, drop height and canister
positions are the controlling factors.
The considered drop heights (distance
from the lowest point of the canister to
the foundation) are 0.5 m, 1.0 m,
1.5 m, and 2.0 m, respectively. The
canister positions during impact
(0°, 30°, 60°, 90°) are illustrated in
Figure 3 (right). Figure 7 shows the
maximum induced tensile stresses in
the different canisters for different
drop height and documents, that peak
tensile stresses can very locally reach
values considerably higher than the
material strength. Therefore, an
additional simulation was performed
assuming a protective cover (layer)
around the SSiC canister. Simulation
of a VW canister (drop height 1 m,
inclination angle 0°) with soft cover
(50 mm thick) confirms significant
reduction of maximum tensile stress
| Fig. 9.
Top: Considered constellations of dropping rock pieces at the time of
impact; Bottom: Induced maximum tensile stresses in VW canister for
different simulation cases.
Decommissioning and Waste Management
SSiC Nuclear Waste Canisters: Stability Considerations During Static and Dynamic Impact ı Yanan Zhao, Heinz Konietzky, Juergen Knorr and Albert Kerber
atw Vol. 66 (2021) | Issue 5 ı September
DECOMMISSIONING AND WASTE MANAGEMENT 46
at the inner boundary of the canister
from 1118 MPa (without cover) to
147 MPa (with cover) (Figure 8).
Free fall of rock blocks
First, preliminary pure elastic simulations
using the VW canister were
performed. Small rock pieces were
considered with weights of 0.5, 1.0
and 2.0 kg, respectively. Drop height
is 2.0 m (distance from the lowest
rock piece point to the highest line
of horizontally disposed canister).
Simulation cases 1 to 4 generate
dynamic line loads, case 5 to 7 lead to
point loads (see Figure 9 (up)).
Figure 9 (down) shows the maximum
induced tensile stresses in a VW canister
during impact for seven loading
cases. Similar results were obtained
for the other canister types. It becomes
obvious from Figure 9 (down), that
(a) even small rock pieces produce
tensile stresses close to the strength of
the SSiC material or even larger
ones and (b) point loading loads to
significant higher values compared to
line loading.
Rock weight
[kg]
D = 20 mm
E = 800 MPa
Such a pure elastic consideration is
too conservative, especially because
the limited strength of the rock pieces
is not taken into account. It has to be
expected that extreme high local
stresses during impact at point or line
contacts lead du massive fracturing of
the rock pieces, so that stresses above
the rock strength will not be reached.
To investigate this phenomenon the
rock pieces were set-up by numerous
distinct elements, so that fracturing
and disintegration can take place if
strength of the rock is exceeded.
Calibration was performed using
typical rock parameters. Figure 10
shows results from a calibration
process for claystone. Figure 10
reveals, that vertical splitting (tensile
cracking) is dominating like typically
observed during uniaxial lab tests.
D = 20 mm
E = 80 MPa
8 5 mm / 130 MPa 12 mm / 70 MPa
D = 80 mm
E = 100 MPa
40 17 mm / 70 MPa
| Tab. 6.
Maximum penetration depth and maximum induced tensile stresses inside a CANDU canister with
soft cover of thickness D and Young’s modulus E during pure elastic collision with claystone rock piece
(drop height 2 m, loading case 1 according to Fig. 16).
| Fig. 10.
DEM-model for claystone: up: stress-strain-curve from
uniaxial compression test, down: DEM model at the
time of failure indication cracking and disintegration.
| Fig. 11.
Top: claystone rock piece in point contact with CANDU canister;
Bottom: sequence of rock splitting process during impact
(drop height 2 m, weight 1 kg).
| Fig. 12.
Top: Maximum tensile stress inside the CANDU canister versus collision
time for rock piece elements with edge length of 4 mm, 6 mm, or 10 mm;
point contact according to Figure 9 (up) (drop height 2 m, weight 1 kg);
Bottom: Maximum tensile stress inside the CANDU canister during impact
with claystone rock pieces for loading case 1 (see Figure 9 (up)) versus
volume ratio (volume of distinct elements to volume of rock piece)
Decommissioning and Waste Management
SSiC Nuclear Waste Canisters: Stability Considerations During Static and Dynamic Impact ı Yanan Zhao, Heinz Konietzky, Juergen Knorr and Albert Kerber
NUCLEAR ENGINEER
EXPERIENCE IN COMPUTER MODELING, NEUTRONICS, CFD, ETC
Our mission and your passion
We are true believers in the necessity of sustainable green energy and we believe
that there is an inextricable close tie between the abundance of accessible energy
in the world, and the well being of our civilization.
As a growth company we are looking for two nuclear engineers or physicists who
have that same passion alongside several years of experience in computer
modeling, neutronics, CFD, etc. We assume that you have experience with
Serpent, OpenMC, MCNP, OpenFoam or similar and that you have a good
understanding of molten salt reactors and how they are different from LWRs.
Who are you?
Curiosity is part of our culture and how we train every day as a team to become
world champions of our mission. We are very curious of who you are and what
purpose you have in life. What is your story and what are your dreams? As team
players we depend on each other whether big or small projects and delivery.
Hence, we make a huge effort to keep our promises and deadlines because it
affects all of us. Our work pace can be intense at times due to our high ambitions,
and errors can be expensive. However, if you like to be challenged Copenhagen
Atomics might be the right place to work for you.
Professionally we hope you have experience with 3D CAD drawings and meshing
of such files. Preferably you also have knowledge in material properties and we
are keen that you are skillful with Linux and programming experience with e.g.
C++ or Python..
You can apply for this position at jobs@copenhagenatomics.com Please send
your CV along with 10 - 20 lines about yourself and your experience with nuclear
computer modeling and why you would like to work with MSRs.
About Copenhagen Atomics
Based in Copenhagen we’re an international growth team of 35 engineers,
technicians and designers who are in the process of developing nuclear power
plants to be manufactured on assembly lines in the future. We expect many new
colleagues to join our company within the next 5 years as we expand our breath
and capabilities even further.
Copenhagen Atomics ApS, Maskinvej 5, 2860 Søborg, Denmark | copenhagenatomics.com
atw Vol. 66 (2021) | Issue 5 ı September
DECOMMISSIONING AND WASTE MANAGEMENT 48
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
Nicolas Wendler
+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
Exemplary, Figure 11 illustrates
the collision process for point load
impact. Figure 12 (up) shows, that
the size of the distinct elements,
which control the fracturing process
in detail, is important to obtain
reliable stress values during the
impact process. The smaller the
elements, the more potential fracture
paths. However, it becomes also
visible, that below a certain threshold
the stresses will not any more
decrease. Compared with the pure
elastic modelling a significant reduction
in induced tensile stresses by a
factor of about 10 is observed. In
additional model runs also larger rock
pieces up to a weight of 512 kg were
considered (see Figure 12 (down)). It
again becomes obvious, that distinct
element resolution has significant
influence on modelling results. To get
reliable results for larger rock pieces
at least at the contact area higher
resolution is necessary. However, one
has also to consider that enhanced
resolution leads to a progressive nonlinear
increase in simulation time.
The effect of a soft cover was also
investigated using the pure elastic
approach. Table 6 shows simulation
results in terms of maximum penetration
depth and maximum induced
tensile stress. It clearly shows that a
soft cover can reduce tensile stresses
considerably, so that even for the
extreme conservative case of pure
elastic interaction, the induced tensile
stresses can be brought below the
strength of the material, which is
about 150 MPa.
Discussion and Conclusions
SSiC has excellent properties in terms
of long lifetime, high strength, low
porosity and excellent resistance
against radiation, high temperatures
and aggressive fluids. In that respect it
is superior to other materials under
consideration for nuclear waste
canisters. As documented, static earth
pressure even in case of high anisotropy
and unfavorable orientation of
the canister in relation to the principal
stresses will not reach the high failure
strength of SSiC canisters for considered
depths up to about 1200 m.
However, the very stiff and brittle
behavior of SSiC needs some more
detailed consideration in case of
dynamic impacts. Such worst case
loading scenarios like rockfall or free
fall of a canister can be investigated
Decommissioning and Waste Management
SSiC Nuclear Waste Canisters: Stability Considerations During Static and Dynamic Impact ı Yanan Zhao, Heinz Konietzky, Juergen Knorr and Albert Kerber
atw Vol. 66 (2021) | Issue 5 ı September
via field tests (large scale drop tests)
and numerical simulations. Under
pure elastic conditions and extreme
loading constellations (point and
line loads) as well as conservative
initial and boundary conditions (stiff
foundation, no damping, no protective
cover etc.) the dynamically
induced tensile stresses inside SSiC
canisters can locally and temporarily
reach – independent on canister type –
maximum tensile stresses beyond the
static tensile strength of SSiC. Even if
we consider that dynamic strength is
somewhat higher than the static one,
several constellations might give rise
of concern.
One should also take into account,
that reaching the failure envelope in
pure elastic simulations just indicate,
that damage is very likely, however,
nothing can be said about extent
and type of damage. Therefore, a
numerical simulation based safety
case should follow two directions: (a)
consideration of an additional cover
to absorb energy during potential
dynamic impact and (b) more realistic
modeling (considering of energy
absorption during collision, fracture
propagation, damping etc.). This
paper provides first hints and results
how these tasks can be handled. The
simulations with soft cover indicate
that a cover of about 10 cm with
stiffness in the order of about 100 MPa
would be able to reduce the dynamically
induced tensile stresses so that
any failure can be avoided.
The presented dynamic simulations
are only a very first step toward a
comprehensive numerical safety case.
The aim was to show, that the most
critical issue of SSiC – the stiff and
brittle behavior – can be managed.
More realistic numerical simulations
should consider the following aspects:
p Incorporation of realistic damping
p Replacement of the elastic models
for all components by calibrated
elastic-plastic models incl. damage
laws
p More profound specification of
load scenarios
p Consideration of dynamic material
properties
In summary, the conclusion can be
drawn, that SSiC is a suitable canister
material if a certain soft cover is used
during transport and emplacement
just in case that unexpected dynamic
collisions (rockfall of free fall of
canister) occur.
Acknowledgment
The conduction of the lab experiments
by Dr. Thomas Frühwirt (TU
Berg akademie Freiberg) is highly
acknowledged. The authors would
like to express their special thanks to
the China Scholarship Council (CSC)
for financially supporting the first
author’s PhD study in Germany.
References
[1] Onofrei, M., Raine, D.K., Brown, L. & Stanchell, F., (1985).
Leaching studies of non-metallic materials for nuclear fuel
immobilisation containers, Proc. Mat. Res. Soc. Symp.,
Materials Research Society., 44: 395-404
[2] Haslam, J.J., Farmer, J.C., Hopper, R.W., Wilfinger, K.R., (2005).
Ceramic coatings for a corrosion- resistant nuclear waste
container evaluated in simulated ground water at 90 °C,
Metallurgical and Materials Transactions., A (36): 1085-1095
[3] Donald W. M., Wen Wua., Francesco, V., (2012). Performance
of PyC, SiC, ZrC coatings in the geologic repository, Nuclear
Engineering and Design., 251: 102-110
[4] Kerber, A. and Knorr, J., (2013). SiC encapsulation of high-level
waste for long-term immobilization, atw 58. Jg Heft 1,
January: 8-13
[5] Lee, M.Y., Brannon, R.M., Bronowski, D.R., (2004). Uniaxial and
triaxial compression tests of silicon carbide ceramics under
quasi-static loading condition, Tech. Rep. SAND2004-6005,
Sandia National Laboratory
[6] Itasca (2020): 3DEC Manuals, Itasca Consulting Group,
Minneapolis, Minnesota, USA
[7] SiCeram (2018): Deutsche Patentanmeldung 10 2018 114
463.6 “Verfahren zum Verbinden von Bauteilen aus SSiC”,
GmbH, Jena, Germany
Authors
Yanan Zhao
TU Bergakademie
Freiberg,
Geotechnical Institute,
Freiberg, Germany
Dr. Yanan Zhao got a master degree in Geotechnical
Engineering from Northwest A&F University in China in
2015, and a PhD degree in Geotechnical Engineering
from TU Bergakademie Freiberg in 2021. Now he works
as post PhD at Powerchina Zhongnan Engineering
Corporation Limited, Changsha, Hunan Province, China.
Prof Dr Heinz
Konietzky
TU Bergakademie
Freiberg,
Geotechnical Institute,
Freiberg, Germany
Heinz.Konietzky@
ifgt.tu-freiberg.de
Prof. Dr. habil. Heinz Konietzky has studied Geotechnical
Engineering. For more than 15 years he has
worked in the private industry worldwide as project
engineer and consultant mainly for civil engineering
projects and for radioactive waste disposal. Since 2006
he works as university professor and director of the
Geotechnical Institute at TU Bergakademie Freiberg.
Prof Dr Jürgen Knorr
GWT-TUD GmbH,
Nuclear Power
Engineering, Dresden,
Germany
juergen.knorr@
tu-dresden.de
Since 1992 Jürgen Knorr is Professor for Nuclear
Engineering at Dresden University of Technology
(Emeritus since 2006). He graduated in physics and
prepared his PhD in nuclear technologies. From 1975
to 1992 he was responsible for the design, construction
and operation of the AKR training reactor (from
the German Ausbildungskernreaktor) in Dresden.
Between 1993 and 2000 Juergen was President of
the German Nuclear Society and Board Member of
the European Nuclear Society. The cooperation
with SiCeram GmbH for the application of high-tech
ceramics in nuclear sector startet in 2003.
Dr Albert Kerber
Managing director and
co-owner SiCeram GmbH,
Jena, Germany
a.kerber@jsj.de
Since 1998 Albert Kerber is the co-owner and
managing director of the company SiCeram GmbH
in Jena, Germany, with the emphasis on high performance
ceramics. After studying chemical engineering,
he gained his doctorate at the Technical University
Karlsruhe. The cooperation with Prof. Knorr started in
the year 2003 and focusses on the application of high
tech ceramic materials in the nuclear sector, especially
for innovative solutions in the field of nuclear waste
disposal.
DECOMMISSIONING AND WASTE MANAGEMENT 49
Decommissioning and Waste Management
SSiC Nuclear Waste Canisters: Stability Considerations During Static and Dynamic Impact ı Yanan Zhao, Heinz Konietzky, Juergen Knorr and Albert Kerber
atw Vol. 66 (2021) | Issue 5 ı September
50
RESEARCH AND INNOVATION
Improving Henry-Fauske Critical Flow
Model in SPACE Code and Analysis of
LOFT L9-3
BumSoo Youn
Introduction The SPACE code offers several options for critical flow model. One of the option is Henry/Fauske –
Moody model. When using this model, Henry-Fauske critical flow model is used for single phase liquid and Moody
model is used for 2-phase flow. For Henry-Fauske model, SPACE code assumes non-equilibrium(NE) factor of 0.14.
In previous OPR1000 SBLOCA analysis methodology based on RELAP5 code, non-equilibrium factor of 1.0 was used to
get more conservative break flow. To develop SBLOCA analysis methodology for OPR1000 using SPACE code, it was
necessary to use different non-equilibrium factor from SPACE default values for Henry-Fauske model. The SPACE code
was improved by adding additional option for Henry/Moody – Moody model, which uses user input non-equilibrium
factor. To accept user input equilibrium factor, the SPACE code is improved by expanding lookup table used in Henry/
Fauske – Moody model. To verify the new model, we perform verification calculations on LOFT L9-3 which is a
representative integral effect test(IET).
Experimental evaluation
Henry-Fauske critical model applied
to existing SPACE codes(NE=0.14)
will predict lower critical flow rates
over the period of transition from
subcooled liquid to two-phase
fluid compared to RELAP5 critical
flow models assuming a nonequilibrium(NE)
factor of 1.0.
Overview of LOFT L9-3
Experiments
The LOFT L9-3[1] experimental
purpose is to provide experimental
data to developers of analysis codes
for ATWS analysis, evaluate alternative
methods of reaching long-term
shutdown without inserting control
rods after ATWS, and verify the
applicability of point kinetics model
or transients. In addition, the experimental
data provided is used to determine
the behavior characteristics of
the primary system due to loss of main
feedwater flow rate on the secondary
side of the steam generator and to
determine the two-phase and overcooling
flow characteristics released
through PORV and SRV at high
pressure.
The LOFT L9-3 experimental
device is a 50MWt pressurized light
water reactor designed at a scale of
1/60 based on a 4-Loop Westinghousetype
nuclear power plant.
As shown in Figure 1 it consists of
five main components and subsystems,
including the reactor core,
primary coolant system, blowdown
mitigation system, emergency core
cooling system, and secondary cooling
system. The blowdown mitigation
system consists of a pump and steam
generator simulation device, a
Quick-opening discharge valve that
| Fig. 1.
LOFT Facility Schematic [Ref.1].
Research and Innovation
Improving Henry-Fauske Critical Flow Model in SPACE Code and Analysis of LOFT L9-3 ı BumSoo Youn
atw Vol. 66 (2021) | Issue 5 ı September
simulates a break, and a tank that
collects coolant released through a
break simulation valve.
The reactor core of the LOFT L9-3
experimental device is approximately
1/2 length(1.68m) of the commercial
reactor core, and the square core
group contains 21 guide tubes out of
225 rod positions(15×15).
Experimental Conditions
The LOFT L9-3 experimental conditions
begin at normal conditions,
such as core power of 48.7MWt, cold
leg temperature of 557.0K, hot leg
temperature of 576.4K, pressurizer
pressure of 14.98MP, and steam
generator pressure of 5.61MPa. The
key steady-state initial conditions of
the experiment are shown in Table 1.
LOFT L9-3 SPACE Modeling
SPACE modeling is shown in Figure 2.
SPACE code input from LOFT L9-3
experiments was written with
reference to NUREG/IA-0192[2]. The
reactor pressure vessel was divided to
simulate the upper and lower cavities
of the core bypass flow, and the core
was modeled as a non-fuel part in the
upper and lower part and a fuel part
represented by three vertical nodes.
The steam generator was modeled
by dividing it into 12 volumes for
U-tube and 19 volumes for secondary.
The main feedwater model was
modeled using TFBC Component,
especially the main feedwater and
steam flow parts, using control logic
to maintain constant pressure on the
secondary side.
The pressurizer was modeled with
nine volumes using the SPACE code
pressurizer model, and the surge line
under the pressurizer is connected to
cell C110 and the pressurizer spray
system is modeled with TFBC Component
C407 and C406. In particular,
Parameter Experiment SPACE
Mass flow rate(kg/s) 467.6 467.63
Hot leg pressure(MPa) 14.98 14.95
Cold leg temperature(K) 557.0 555.04
Hot leg temperature(K) 576.4 574.56
Power level(MWt) 48.7 48.7
PZR Liquid temperature(K) 615.2 614.78
PZR Pressure(MPa) 14.98 14.98
SG Liquid level(m) 3.15 3.19
SG Pressure(MPa) 5.61 5.55
SG Mass flow rate(kg/s) 25.7 25.6
| Tab. 1.
Initial value of experiment.
in the case of spray system, the spray
system is operated using the trip
signal so that fluid from cold
leg(C150) enters the pressurizer
through TFBC Component C407.
In the evaluation of LOFT L9-3
experiments using SPACE code, the
normal state was verified using null
transients, and then the transient
state was simulated using the Restart
file and the results were evaluated.
LOFT L9-3 Evaluation Results
Figure 3 shows the pressure change of
the pressurizer. According to the
experimental values in the figure, the
pressure of the system gradually
increases as the main feed water
supplied to the steam generator is
initially closed and the heat transfer
from the primary to the secondary
side of the steam generator decreases.
The pressurizer pressure increases
and reaches the setting of the pressurizer
spray system. When the setting
is reached, the pressurizer spray
system is activated and the pressurizer
pressure is reduced at 31 seconds. The
continuous decrease in heat transfer
to the steam generator causes the
pressure to rise again. The pressure of
the pressurizer is increased further as
the steam generator MSCV closes at
67.3 seconds. The pressurizer pressure
then reaches the opening setting of
the PORV and decreases when the
PORV is opened at 73.8 seconds.
However, due to the absence of a
replenishment of the main feedwater
of the steam generator, the pressure
rises again and the SRV setting of the
RESEARCH AND INNOVATION 51
| Fig. 2.
LOFT L9-3 Facility Nodalization for SPACE Code Verification.
Research and Innovation
Improving Henry-Fauske Critical Flow Model in SPACE Code and Analysis of LOFT L9-3 ı BumSoo Youn
atw Vol. 66 (2021) | Issue 5 ı September
RESEARCH AND INNOVATION 52
| Fig. 3.
Pressure change of the pressurizer.
pressurizer is reached at 96.8 seconds.
The pressurizer pressure reaches
the maximum pressure value at
97.5 seconds and then decrease. After
120 seconds, the pressurizer PORV
and SRV repeat open and close,
causing the pressure to repeat rise and
fall within a small range.
The SPACE predictions also show
similar results to the experimental
results. Initially, the main feedwater to
the steam generator is interrupted,
causing the pressurizer pressure to rise
just like the experiment. The pressure
that was decreasing due to the operation
of the pressurizer spray system
gradually increases again after the
spray system stops. The increased
pressure is reduced again in 55 seconds
by the operation of the spray system.
The MSCV of the steam generator
closes at 67.3 seconds, resulting in a
rapid increase in pressure as shown in
the experimental results. The pressure
then reaches the open setting of the
pressurizer PORV, which opened at
73.8 seconds, but continue to rise,
somewhat different from the experimental
value trend. The rising pressure
decreases at 90 seconds, but
without the com plement of the steam
generator’s main feedwater, the
pressure rises again and reaches a
| Fig. 4.
Pressure change of the steam generator.
maximum pressure slightly higher
than the experimental results at
103 seconds. Subsequently, the pressure
s reduced due to the operation of
the PORV, SRV, and pressurizer spray
systems of the steam generator, and
after 120 seconds, the rise and fall are
repeated near 15.5MPa to 16MPa.
The new Henry-Fauske critical
flow model shows more similar results
to experimental results than existing
models.
Figure 4 shows the change in the
pressure of the steam generator.
According to the results of the
experiment, the pressure of the steam
generator will gradually increase as
the main feedwater of the steam
generator is closed. As the level of the
steam generator gradually decreases,
and steam generator U-tubes become
uncovered heat transfer area decreases,
and the pressure that was
gradually rising decreases rapidly. The
pressure then rises as MSCV closes.
The rising pressure of the steam
generator has slowed from about
100 seconds, when the PORV and SRV
discharge flow of the pressurizer were
maximum, and has since remained at
a constant pressure(6.48MPa) while
maintaining a slightly higher pressure
than the initial value.
As the main feedwater of the steam
generator is stopped, the SPACE result
is also a graual increase in pressure,
as is the result of the experiment.
Gradually rising pressure peaks at
50 seconds and decreases with a slope
similar to the experimental value.
However, with MSCV closing at
673 seconds, the SPACE code prediction
rises sharply from the experimental
value after approximately
70 seconds. The rising pressure of the
steam generator tends to be similar to
the experimental value after about
130 seconds and maintains a constant
pressure.
Figure 5 shows the changes core
power. According to the experimental
results, if the main feedwater of the
steam generator is closed, the primary
system heat removal is lost and the
temperature and pressure of the
primary coolant are increased. As the
temperature of the coolant cooling
the core increases, the core power
decreases gradually due to the feedback
effect of the moderator. At
67.3 seconds, when the MSCV of the
steam generator is closed, the core
power is also rapidly reduced.
The SPACE code predictions tend
to decrease somewhat faster than the
experimental value between 70 and
| Fig. 5.
Core power change.
| Fig. 6.
Steam generator water level change.
Research and Innovation
Improving Henry-Fauske Critical Flow Model in SPACE Code and Analysis of LOFT L9-3 ı BumSoo Youn
atw Vol. 66 (2021) | Issue 5 ı September
| Fig. 7.
Coolant temperature change.
160 seconds, but the overall trend is
the same, and after 160 seconds, they
are almost the same.
Figure 6 shows the change in
water level on the secondary side of
the steam generator. According to the
results of the experiment, the water
on the secondary side of the steam
generator will be reduced due to heat
transfer with the primary side as the
main feedwater of the steam generator
is closed. The water level, which
had been continuously decreasing at
the same time as the main feed water
closed, will not completely depleted
after 120 seconds, and will gradually
stabilize at about 0.2 m high and
remain constant.
The overall trend predicted by the
SPACE code is similar to the experimental
results. However, the results of
the SPACE code begin to decrease in
water level and are almost depleted by
approximately 85 seconds. After that,
it remains completely depleted and in
a normal condition.
Figure 7 shows the temperature of
the coolant due to transient conditions.
Experimental results show
that the temperature of the coolant is
slowly increasing as the main feedwater
is closed. The increasing
temperature of the coolant rises
rapidly after 60 seconds due to the
continued loss of the heat sink, and
then the MSCV of the steam generator
closes at 67.3 seconds, which in creases
the temperature even more rapidly.
After 100 seconds, when the pressurizer
pressure is at its peak, the
pressure increase is slowed due to the
operation of SRV and PORV of the
pressurizer, and thus the temperature
increase is slowed. As the pressure of
the system is maintained constant, the
temperature of the coolant is maintained
constant.
As previously shown in Table 1,
the steady-state temperature conditions
using the SPACE code
| Fig. 8.
Discharge flow rate.
represent values about 2K lower than
the experimental conditions, so there
is a slight difference from the experiment
at the beginning of the transient
results. Although there is a difference
at the starting point, the result of
SPACE code also gradually increases
the temperature as the steam generator
main feedwater is stopped. As in
the experiment, the temperature rises
rapidly after 60 seconds, and remains
constant after 100 seconds.
Figure 8 shows the discharge flow
rate through PORV and SRV during
the transient. The main feedwater
stops, the pressure gradually rises,
and after 67.3 seconds the MSCV of
the steam generator closes, reaching
the opening set point of the PORV. At
100 seconds when the pressurizer
pressure reaches its maximum, the
discharge flow rate is maximum,
and after that, the PORV and SRV are
repeatedly opened and closed.
We compare the results with the
existing Henry-Fauske critical flow
model using the newly added Henry-
Fauske critical flow model in the
simulation with SPACE code for
discharge of coolant through the
PORV and the SRV. Overall, the
opening points are similar, but there
are some differences in the amount of
discharge. When using the newly
added Henry-Fauske critical flow
model, we can confirm that the
maximum discharge flow rate is
higher and conservatively predicted.
Conclusions
A new Henry/Fauske - Moody critical
flow model option was added to the
SPACE code. The SPACE code is
improved by expanding lookup table
used in Henry/Fauske - Moody model.
For validation of improved model,
LOFT L9-3 integral effect test is
analyzed. The new model show better
agreement with the experiment
results. The new critical flow model
will be used in the development of
SBLOCA analysis methodology of
OPR1000-type and WH 3-loop type
nuclear power plants.
Acknowledgments
This work was supported by the Korea
Hydro & Nuclear Power(KHNP)
(A19LP05, Establishment of optimal
evaluation system for safety analysis
of OPR1000and Westinghouse type
nuclear power plant(1)).
References
ı
ı
NUREG/CR-3427 ‘Experiment Analysis and Summary Report
for LOFT ATWS Experiments L9-3 and L9-4’.
NUREG/IA-0192 ‘Assessment of RELAP5/MOD3.2.2 Gamma
with the LOFT L9-3 Experiment Simulating an Anticipated
Transient without Scram’.
Author
BumSoo Youn
Senior Researcher
Nuclear Safety
Analysis Group
Central Research
Institute, Korea Hydro
and Nuclear Power Co.,
LTD., Republic of Korea
bsyoun81@khnp.co.kr
BumSoo Youn studied Nuclear Engineering and
completed his M.S in 2009 at the Kyunghee University.
After graduation, he worked as a researcher at KEPRI
and have been working as a Senior Researcher at
KHNP since 2011. He does research in the following
areas: Nucelar Safety Analysis, Thermal Hydraulic
Analysis, Design Based Accident Analysis, Beyond
Design Based Accident Analysis.
RESEARCH AND INNOVATION 53
Research and Innovation
Improving Henry-Fauske Critical Flow Model in SPACE Code and Analysis of LOFT L9-3 ı BumSoo Youn
atw Vol. 66 (2021) | Issue 5 ı September
RESEARCH AND INNOVATION 54
Non-destructive Radioactive Tracer
Technique in Evaluation of Photodegraded
Polystyrene Based Nuclear
Grade Ion Exchange Material
Pravin U. Singare
1 Introduction Poly styrene-divinyl benzene type ion exchange materials having sulfonic acid and quaternary
ammonium functional groups are widely used in various nuclear industries related applications where prolonged
service in adverse environmental condition is required. In nuclear industrial applications organic resin materials are
used for elimination of radioactive and other ionic impurities from water in moderator circuits [1]. In view of the
extensive application of organic ion exchange materials in nuclear industries, their technological development started
long back and are now made available at commercial scale to satisfy the needs of these industries. In spite of widespread
applications of ion exchange materials, there are some problems related to their durability over a prolonged time
period. The consistent performance of these materials depends upon the chemical nature of polymeric resin material,
adverse environmental factors namely humidity, acid rain, temperature fluctuation and time of exposure to ultraviolet
(UV) radiation, presence of traces of solvents, catalyst, metals and metal oxides from processing equipment and
containers. In outdoor applications, these ion exchange materials very often deteriorate due to weathering process
creating negative impact on their lifetime [2, 3]. The inability of polymeric resin materials to resist degradation
conditions often becomes visible within a short span. In some situations, few hours of exposure to degradation
conditions may result in extensive structural damage. The degradation process may lead to macromolecular chain bond
breaking resulting in decrease in average molar mass or may lead to cross-linking thereby increasing the molar mass.
Aging of polymeric materials will result alteration of polymer properties in long-term due to weathering conditions [4].
As a result, there is an increasing challenge in front of manufacturers to ensure about the life expectancy guarantee of
their polymeric resin materials, particularly under the conditions which are difficult for inspection or failure catastrophic
[5]. The wide spread utilization of polymeric resin materials has created the condition of emergence related to
performance durability of these materials under stringent long-term exposure conditions. These problems related to
durability of polymeric resin materials are associated with in-service environmental conditions and handling procedures
during maintenance, repair and modifications. Since the repair or replacement of degraded polymeric resin materials
is both labour and capital intensive, the durability of these materials is one of the critical issues from both safety and
economic point of view.
The photo-degradation brought
about by solar UV radiations is the
most serious problem associated with
an organic based resin. The solar
waves consist of UV radiations in the
wavelengths range of 290 to 400 nm,
corresponding to the energies in the
range of 415 to 300 kJ/mol. These
energies associated with the solar UV
radiations are similar to the bond
energies of many organic molecules.
When specific functional groups of
an organic compound absorb UV
radiation the chemical reactions
are initiated liberating free radicals
which further speedup the photo
degradation process. Among the UV
radiations, most harmful are the UV-B
radiations which are in the wavelength
range of 280 to 315 nm having
high energy in the order of
426-380 KJ mol -1 , while UV-A radiations
in the wavelength range of 315
to 400 nm are less harmful having
comparatively less energy in the order
of 389 and 300 KJ mol -1 [6]. The
deleterious effect of these radiations
will depend on the chemical nature of
the material, climatic conditions
namely temperature, humidity, exposure
time, presence of traces of
solvents, catalyst, metals and metal
oxides from processing equipment
and containers [7]. Photo-degradation
can take place via chain breaking
or cross-linking in absence of oxygen
and via photo-oxidative degradation
in presence of oxygen. In most
polymers, elevation in temperature
condition and prolonged exposure
to pollutants will raise the photooxidative
sensitivity thereby triggering
the photo-oxidative degradation
process [8]. Exposure to UV radiations
is usually observed superficially which
is indicated in terms of embrittlement
(surface cracking), discolouration
and loss of transparency. Further
exposure to UV radiations will bring
about photolytic, photo-oxidative, and
thermo-oxidative reactions in the
resin materials resulting in the
photo-degradation of polymeric resin
materials which is usually superficially
and slowly degrades the entire
material by changing the chemical
structure of the polymeric material
[9]. Depending upon the nature of the
polymeric resin material, the photo
degradation may results in polymer
chain scission, cross-linking leading
to irreversible change in physicochemical
conditions and also changes
at the molecular level [10]. Subsequent
to UV exposure, the polymeric
resin material follows different degradation
routes via formation of free
radicals and breaking of the polymer
chains thereby losing its mechanical
properties and molecular weight
making the materials useless after
some time [11].
The photo degradation of industrial
grade ion exchange resins operating
under severe environ mental stress
conditions is a serious problem with
economic and environmental implications.
Previous research focused
mainly on the study of bulk mechanical
properties, surface chemistry
and surface morphology of the
polymeric materials exposed to UV
radiations for different exposure
period [12, 13]. The study was also
performed to understand the role
of sensitizers in accelerating the
efficiency of the photo-degradation
Research and Innovation
Non-destructive Radioactive Tracer Technique in Evaluation of Photo- degraded Polystyrene Based Nuclear Grade Ion Exchange Material ı Pravin U. Singare
atw Vol. 66 (2021) | Issue 5 ı September
and the mechanism of UV light
induced photo-oxidation and photolysis
processes in polymeric materials
[14, 15]. A detail review was published
on photo-degradation of polystyrene
polymers which emphasise mainly
on the degradation mechanism of
polymers and role of stabilisers in
photo- degradation [16]. However, in
spite of extensive application of
polymeric resin materials in nuclear as
well as in the chemical industry, not
much work is reported in the literature
related to performance of photodegraded
polymeric resin materials
[17]. Therefore, in the present investigation,
a systematic study was
performed on the ion uptake reaction
kinetics and uptake behaviour of fresh
and photo-degraded nuclear grade anion
exchange resin Indion GS 300, using
non-destructive radiotracer
analytical technique.
2 Materials and Methods
2.1 Ion exchange resin
The anion exchange resin Indion GS-
300 as supplied by the manufacturer
(Ion exchange India Limited,
Mumbai) was a nuclear grade resin
in the OH-form with quaternary
ammonium functional group having
polystyrene matrix. The particle size
was in the range of 0.3 to 1.2 mm,
operating pH range was 0-14,
maximum operating temperature of
60 °C having the exchange capacity of
1.40 meq./mL. The moisture content
of the resin was 51.9 %.
2.2 Radio isotope used
The 82 Br radioactive tracer isotope
used here was supplied by Board of
Radiation and Isotope Technology
(BRIT), Mumbai, India. The isotope
used is an aqueous solution of
ammonium bromide in dilute
ammonium hydroxide having half life
of 36 d, radioactivity of 5mCi and
γ-energy of 0.55 MeV [18].
2.3 Conditioning
of the ion exchange resin
The resin grains of 30-40 mesh size
were used for the present investigation.
The soluble impurities of the
resin were removed by repeated
soxhlet extraction using water. Moreover,
distilled methanol was used
occasionally to remove non-polymerized
organic impurities. The resin
in hydroxide form was converted into
bromide form with 10 % potassium
bromide in a conditioning column.
Then the resin was washed with
distilled deionized water until the
washings were bromide free. The
resin in the bromide form was air
dried over P 2 O 5 and used for further
study (hereafter referred as fresh
resin).
2.4 Photo-degradation of ion
exchange resin
The photo-degradation of the resin
was carried in a UV chamber in an
ambient atmosphere where the
temperature was nominally 25 °C-
29 °C, with a humidity of 30-50 %.
The resin was photo-degraded in a UV
chamber by exposing them to radiation
of wavelength 284 nm and
384 nm for 24 h. After 24 h the
degraded resin was washed with
distilled water and ethanol mixture to
remove the degraded polymeric
fractions. The resin was then air dried
and used for further study (hereafter
referred as λ 384 photo degraded resin
and λ 284 photo degraded resin).
2.5 Study on bromide ion uptake
and reaction kinetics
The fresh and degraded resins in
bromide form weighing 1.000 g (m)
were equilibrated with 200 mL (V)
labeled bromide ion reaction medium
(0.200M) of known initial activity
(Ai) at a constant temperature of
30.0 °C. The temperature of the
reaction medium was maintained
constant using an in-surf water bath.
The bromide ion-isotopic exchange
reaction can be represented as:
R-Br + Br* - (aq.) ⇌ R-Br* + Br - (aq.)
(1)
Here R-Br represents ion exchange
resin in bromide form; Br* - (aq.) represents
aqueous bromide ion reaction
medium labeled with 82 Br radiotracer
isotope.
The activity in counts per minute
(cpm) of 1.0 mL of the reaction
medium was measured at an interval
of every 2 minutes for 3 h. The solution
was transferred back to the same bottle
containing labeled reaction medium
after measuring the activity. The final
activity (A f ) of the equili brated labeled
bromide ion reaction medium was
measured after 3h. The activity in
counts per minute (cpm) was measured
with γ-ray spectro meter equipped with
NaI (Tl) scintillation detector. The
activity measured at various time intervals
was corrected for background
counts. The procedure adopted for
labeling the reaction medium was
same as mentioned previously [19].
The percentage and amount of bromide
ions exchanged on the resin in
mmol were obtained from the A i , A f ,
values and the amount of exchangeable
bromide ions in 200 mL of reaction
medium. The study was extended
further by equilibrating the fresh and
degraded resins with 0.300M and
0.500M labeled bromide ion reaction
medium at 30.0 °C. Similar set of
experiments were repeated by equilibrating
1.000 g of fresh and degraded
resins in bromide form with 0.200M
labeled bromide ion reaction medium
at higher temperatures up to 45.0 °C.
2.6 Fourier-transform infrared
spectroscopy (FTIR) analysis
FTIR analysis of fresh and photodegraded
resins was performed using
a Bruker Optik, ALPHA-T FTIR
spectrometer having gold mirror
interferometer with ZnSe beam
splitter. The ATR probe consisted of a
zinc selenide focusing element and a
diamond internal reflectance element.
The probe was brought into intimate
contact with the sample surface using
mechanical pressure. 32 scans were
collected over the spectral range of
400 cm -1 to 4000 cm -1 . The probe was
purged with dry air and background
spectra were collected before each
sample spectrum was taken.
2.7 Scanning Electron
Microscopy (SEM) analysis
The degradation studies of ion
exchange resins was also studied by
examining the surface morphology of
fresh and photo degraded resin
samples using JSM-6380LA Scanning
Electron Microscope (Jeol Ltd.,
Japan). The powders were precisely
fixed on an aluminum stub using
double sided graphite tape and then
were made electrically conductive by
coating in a vaccum with a thin layer
of carbon, for 30 seconds and at 30 W.
The pictures were taken at an
excitation voltage of 15 KV and a
magnification of ×250 to ×500.
3 Results and Discussion
3.1 Effect of photo-degradation
on isotopic ion uptake
reaction kinetics
In the present investigation it was
observed that the initial activity of
solution decreases rapidly due to
rapid ion uptake reaction, then due to
slow ionic uptake the activity of the
solution decreases slowly due and
finally remains nearly constant.
Previous investigations have shown
that the above ionic uptake reactions
are of first order, as a result the
logarithm of activity when plotted
RESEARCH AND INNOVATION 55
Research and Innovation
Non-destructive Radioactive Tracer Technique in Evaluation of Photo- degraded Polystyrene Based Nuclear Grade Ion Exchange Material ı Pravin U. Singare
atw Vol. 66 (2021) | Issue 5 ı September
RESEARCH AND INNOVATION 56
against time gives a composite curve
in which the activity initially decreases
sharply and thereafter very
slowly giving nearly straight line,
evidently rapid and slow ion adsorption
reactions were occurring simultaneously
[19]. The activity exchanged
due to rapid, slow uptake reactions as
well as the specific reaction rate (k)
of rapid ion uptake reactions were
calculated in the same way as
explained previously [20-22]. The
amount of bromide ions exchanged
(mmol) on the resin were obtained
from the initial and final activity of
solution and the amount of ions in
200mL of solution.
It was observed that, under identical
experimental conditions, with rise
in temperature from 30.0 °C to 45.0 °C,
the k values (min -1 ) for bromide ion
uptake reactions were observed to decrease
for fresh as well as for λ 384 and
λ 284 photo- degraded resins (Table 1).
Thus for 0.200M bromide ion concentration
when the temperature was
raised from 30.0 °C to 45.0 °C, the k
values decrease from 0.238 to 0.226
min -1 for fresh resin, from 0.198 to
0.181 min -1 for λ 384 photo-degraded
resin and from 0.156 to 0.142 min -1 for
λ 284 photo-degraded resin (Table 1).
It was observed that, under identical
experimental conditions, with rise
in concentration of bromide ions in
the solution from 0.200M to 0.500M,
the k values (min -1 ) for ion uptake
reactions were observed to increase
for fresh as well as for λ 384 and λ 284
photo-degraded resins (Table 2).
Thus at 30.0 °C when the bromide
ion concentration was raised from
0.200M to 0.500M, the k values increase
from 0.238 to 0.276 min -1 for
fresh resin, from 0.198 to 0.223 min -1
for λ 384 photo-degraded resin and
from 0.156 to 0.176 min -1 for λ 284
photo-degraded resin (Table 2).
From the results, it appears that
under identical experimental conditions,
ion uptake reaction rate
decreases sharply as the photodegradation
wavelength decreases
from 384 nm to 284 nm. Thus for
0.200M bromide ion concentration at
a constant temperature of 30.0 °C, the
k value was 0.238 min -1 for fresh
resin, which decreases to 0.198 min -1
for λ 384 photo-degraded resin, which
further decreases to 0.156 min -1 for
λ 284 photo-degraded resin (Table 1).
Comparing the ion uptake reaction
rate (k) in min -1 for reactions
performed at different temperatures
of reaction medium and concentration
of labeled bromide ion solution,
it was observed that the k values
decrease with decrease in photodegradation
wavelength.
Temperature
of reaction
medium
°C
reaction
rate of rapid
isotopic
ion uptake
process
(min -1 )
Fresh resin λ 284 photo degraded resin λ 384 photo degraded resin
Amount
of isotopic
ions uptake
(mmol)
% of
isotopic
ions
uptake
reaction
rate of rapid
isotopic
ion uptake
process
(min -1 )
Amount
of isotopic
ions uptake
(mmol)
% of
isotopic
ion
uptake
reaction
rate of rapid
isotopic
ion uptake
process
(min -1 )
Amount
of isotopic
ion uptake
(mmol)
% of
isotopic
ion
uptake
30.0 0.238 21.9 54.8 0.156 18.4 45.9 0.198 20.2 50.5
35.0 0.233 19.9 49.7 0.152 15.1 37.8 0.19 18.1 45.3
40.0 0.229 17.8 44.6 0.147 11.9 29.7 0.186 16.0 40.1
45.0 0.226 16.1 40.3 0.142 8.6 21.6 0.181 14.0 34.9
Energy of
activation
(kJ.mol -1 )
Enthalpy of
activation
(kJ.mol -1 )
Free energy of
activation
(kJ.mol -1 )
Entropy of
activation
(kJ.K -1 mol -1 )
-2.77 -5.05 -4.66
-5.35 -7.63 -7.24
64.66 63.65 63.86
-0.231 -0.236 -0.234
| Tab. 1.
Effect of temperature of reaction medium on isotopic ion uptake reaction kinetics and isotopic uptake using fresh/photo-degraded Indion GS 300 resins.
Amount of ion exchange resin in bromide form = 1.000 g; Concentration of labeled bromide ion reaction medium = 0.200M; Volume of labeled bromide ion reaction medium = 200 mL;
Amount of exchangeable bromide ions in 200 mL labeled reaction medium = 40.00 mmol.
Concentration
of ions
in the
reaction
medium
(M)
Amount
of ions in
200 mL
labeled
solution
(mmol)
reaction
rate of
rapid
isotopic
ion uptake
process
(min -1 )
Fresh resin λ 284 photo degraded resin λ 384 photo degraded resin
Amount
of isotopic
ion
uptake
(mmol)
% of
isotopic
ion
uptake
reaction
rate of
rapid
isotopic
ion uptake
process
(min -1 )
Amount
of isotopic
ion
uptake
(mmol)
% of
isotopic
ion
uptake
reaction
rate of
rapid
isotopic
ion uptake
process
(min -1 )
Amount
of isotopic
ion uptake
(mmol)
% of
isotopic
ion
uptake
0.200 40.00 0.238 21.9 54.8 0.156 18.4 45.9 0.198 20.2 50.5
0.300 60.00 0.250 35.5 59.2 0.162 29.8 49.6 0.207 32.6 54.4
0.500 100.00 0.276 68.7 68.7 0.176 56.7 56.7 0.223 63.8 63.8
| Tab. 2.
Concentration effect on isotopic ion uptake reaction kinetics and isotopic uptake using fresh/photo-degraded Indion GS 300 resins.
Amount of ion exchange resin = 1.000 g; Volume of labeled ionic reaction medium = 200 mL; Temperature of reaction medium = 30.0 °C.
Research and Innovation
Non-destructive Radioactive Tracer Technique in Evaluation of Photo- degraded Polystyrene Based Nuclear Grade Ion Exchange Material ı Pravin U. Singare
atw Vol. 66 (2021) | Issue 5 ı September
3.2 Effect of photodegradation
on percentage
isotopic ion uptake
It was observed that for 0.200M
labeled bromide ion solution, as the
temperature of the reaction medium
increases from 30.0 °C to 45.0 °C, the
percentage of isotopic ion uptake
decreases by 14.5 % from 54.8 % to
40.3 % for fresh resins; by 15.6 % from
50.5 % to 34.9 % for λ 384 photodegraded
resin and maximum by
24.3 % from 45.9 % to 21.6 % for
λ 284 photo-degraded resin (Table 1).
For same temperature of reaction
medium, similar decrease in percentage
of bromide ion uptake was
observed as the photo-degradation
wavelength decreases from 384 nm to
284 nm. Thus for 0.200M labeled
bromide ion solution at a constant
temperature of 30.0 °C, in case of
fresh resin the percentage of ion
uptake was 54.8 %, while for λ 384
photo- degraded resin 50.5 % isotopic
ion uptake was observed, indicating
4.3 % decrease. Similarly, for λ 284
photo-degraded resin, the percentage
of isotopic ion uptake was 45.9 %
indicating 8.9 % decrease with
reference to fresh resin (Table 1).
Thus, it was observed that the
decrease in wavelength has higher
photo-degradation effect on the
resin which is reflected by higher
decrease in bromide ion uptake by the
resin.
It was observed that at 30.0 °C, as
the concentration of labelled bromide
ion solution increases from 0.200M to
0.500M, the percentage of isotopic ion
uptake increases by 13.9 % from
54.8 % to 68.7 % for fresh resins; by
13.3 % from 50.5 % to 63.8 % for λ 384
photo-degraded resin and by 10.8 %
from 45.9 % to 56.7 % for λ 284 photodegraded
resin (Table 2). Thus, as
the photo-degradation wavelength
decreases the degradation effect on
the resin was more which is reflected
by less increase in isotopic ion uptake
by the resin.
3.3 Thermodynamics of isotopic
ion uptake reactions
using fresh and photodegraded
resins
The energy of activation (E a ) for the
bromide ion uptake reactions taking
place in Indion GS 300 were calculated
by using Arrhenius equation
[23].
k = A × e -Ea/RT (2)
The plot of log (10) k against 1/T gives a
straight line graph (Figure 1), from
the slope of the plot, energy of activation
E a values for ion uptake reactions
using fresh and photo- degraded resins
were calculated by the equation [23].
E a = slope × -2.303x R (3)
The enthalpy of activation ΔH ‡ value
for the bromide ion uptake reactions
using fresh and photo-degraded resins
were calculated by using the Eyring-
Polanyi equation [23, 24].
log 10 k/T = -ΔH ‡ /2.303RT +
log 10 k B /h + ΔS ‡ /2.303R
(4)
Where:
k = reaction rate constant
T = absolute temperature
ΔH ‡ = enthalpy of activation
R = gas constant (8.314J.K -1 .mol -1 )
k B = Boltzmann constant
(1.3806 ×10 -23 J⋅K -1 )
h = Planck’s constant
(6.6261×10 -34 J⋅s)
ΔS ‡ = entropy of activation
RESEARCH AND INNOVATION 57
The plot of log 10 k/T versus 1/T gives a
straight-line graph (Figure 2), from
the slope of which enthalpy of
activation ΔH ‡ values for the bromide
ion uptake reactions using fresh and
photo-degraded resins were calculated
by the equation
Slope = ΔH ‡ /-2.303R (5)
| Fig. 1.
Arrhenius plot to determine energy of activation (Ea) for bromide isotopic ion uptake reactions
performed by using fresh and photo-degraded Indion GS 300 resins.
Amount of ion exchange resin in bromide form = 1.000 g; Temperature range = 30.0-45.0 °C; Concentration of labeled
exchangeable bromide ion solution = 0.200M; Volume of labeled bromide ion solution = 200 mL; Amount of exchangeable
bromide ions in 200 mL labeled solution = 40.00 mmol.
From the intercept of the above plot,
the entropy of activation ΔS ‡ values
for the bromide ion uptake reactions
using fresh and photo-degraded resins
were calculated by the equation
Intercept = 2.303 × log 10 (k B /h)
+ ΔS ‡ /R(6)
Knowing the values of enthalpy of
activation ΔH ‡ and entropy of activation
ΔS ‡ , free energy of activation ΔG ‡
for bromide ion uptake reactions
using fresh and photo-degraded resins
was calculated by the equation
ΔG ‡ = ΔH ‡ -TΔS ‡ (7)
| Fig. 2.
Eyring-Polanyi plot to determine the enthalpy of activation ΔH ‡ and entropy of activation ΔS ‡ for bromide
isotopic ion uptake reactions performed by using fresh and photo-degraded Indion GS 300 resins.
Amount of ion exchange resin in bromide form = 1.000 g; Temperature range = 30.0-45.0 °C; Concentration of labeled
exchangeable bromide ion solution = 0.200M; Volume of labeled bromide ion solution = 200 mL; Amount of exchangeable
bromide ions in 200 mL labeled solution = 40.00 mmol.
It was observed that during isotopic
ion uptake reactions using the fresh
resin, the values of energy of activation
(-2.77 kJ.mol -1 ), enthalpy of activation
(-5.35 kJ.mole -1 ), free energy of activation
(64.66 kJ.mol -1 ) and entropy
of activation (-0.231 kJ.K -1 mol -1 );
Research and Innovation
Non-destructive Radioactive Tracer Technique in Evaluation of Photo- degraded Polystyrene Based Nuclear Grade Ion Exchange Material ı Pravin U. Singare
atw Vol. 66 (2021) | Issue 5 ı September
RESEARCH AND INNOVATION 58
| Fig. 3.
Correlation between temperature of reaction medium and bromide isotopic ion uptake reaction rate of
the reactions performed by using fresh and photo-degraded Indion GS 300 resins.
Amount of ion exchange resin in bromide form = 1.000 g; Concentration of labeled bromide ion reaction medium = 0.200M;
Volume of labeled bromide ion reaction medium = 200 mL; Amount of exchangeable bromide ions in 200 mL labeled reaction
medium = 40.00 mmol
Correlation coefficient (r) for fresh resin =-0.9938; Correlation coefficient (r) for λ 384 photo degraded resin =-0.9886;
Correlation coefficient (r) for λ 284 photo degraded resin = -0.9986
| Fig. 4.
Correlation between temperature of reaction medium and percentage of bromide isotopic ion uptake for
the reactions performed by using fresh and photo-degraded Indion GS 300 resins.
Amount of ion exchange resin in bromide form = 1.000 g; Concentration of labeled bromide ion reaction medium = 0.200M;
Volume of labeled bromide ion reaction medium = 200 mL; Amount of exchangeable bromide ions in 200 mL labeled reaction
medium = 40.00 mmol
Correlation coefficient (r) for fresh resin =-0.9992; Correlation coefficient (r) for λ 384 photo degraded resin =-1.0000;
Correlation coefficient (r) for λ 284 photo degraded resin = -1.0000
| Fig. 5.
Correlation between concentration of labeled bromide ionic solution and bromide isotopic ion uptake
reaction rate of the reactions performed by using fresh and photo-degraded Indion GS 300 resins.
Amount of ion exchange resin = 1.000 g; Volume of labeled ionic reaction medium = 200 mL;
Temperature of reaction medium = 30.0 °C
Correlation coefficient (r) for fresh resin = 0.9998; Correlation coefficient (r) for λ 384 photo degraded resin = 0.9995;
Correlation coefficient (r) for λ 284 photo degraded resin = 0.9993
which increases to -4.66 kJ.mol -1 ,
-7.24 kJ.mol -1 , 63.86 kJ.mol -1 and
-0.234 kJ.K -1 mol -1 respectively for
λ 384 photo-degraded resin; which further
increases to -5.05 kJ.mol -1 , -7.63
kJ.mol -1 , 63.65 kJ.mol-1 and -0.236
kJ.K -1 mol -1 respectively for λ 284 photo-degraded
resin under similar
experimental conditions (Table 1).
The thermodynamic parameters calculated
here suggest that decrease in
wavelength of UV radiations has
more degradation effect on the resin
re sulting in less thermodynamic
feasibility of the isotopic ion uptake
reactions.
3.4 Statistical Correlations
The results of present investigation
show a strong negative correlation
between temperature of the medium
and bromide ion uptake reaction rate
(min -1 ) for the reactions performed
by using fresh, λ 284 photo degraded
and λ 384 photo degraded resins,
having r values of -0.9938, -0.9986
and -0.9886 respectively (Figure 3).
There also exist strong negative
correlation between percentage of
bromide ion uptake and temperature
of the medium for the reactions performed
by using fresh, λ 284 photo
degraded and λ 384 photo degraded
resins, having r values of -0.9992,
-1.0000 and -1.0000 respectively
(Figure 4).
However, a strong positive correlation
was observed between the concentration
of labeled ionic medium
and bromide ion uptake reaction rate
(min -1 ) for the reactions performed by
using fresh, λ 284 photo degraded and
λ 384 photo degraded resins, having r
values of 0.9998, 0.9993 and 0.9995
respectively (Figure 5). Also, a strong
positive correlation was observed
between the concentration of labeled
ionic medium and percentage of
bromide ion uptake for the reactions
performed by using fresh, λ 284 photo
degraded and λ 384 photo degraded
resins, having r values of 0.9998,
0.9999 and 0.9990 respectively
(Figure 6).
3.5 Characterisation of fresh
and photo-degraded resin
| Fig. 6.
Correlation between concentration of labeled bromide ionic solution and percentage of bromide isotopic
ion uptake for the reactions performed by using fresh and photo-degraded Indion GS 300 resins.
Amount of ion exchange resin = 1.000 g; Volume of labeled ionic reaction medium = 200 mL;
Temperature of reaction medium = 30.0 °C
Correlation coefficient (r) for fresh resin = 0.9998; Correlation coefficient (r) for λ 384 photo degraded resin = 0.9990;
Correlation coefficient (r) for λ 284 photo degraded resin = 0.9999
3.5.1 FTIR spectrum of fresh and
photo-degraded Indion GS
300 resin
The IR spectrum of the fresh Indion
GS 300 resin is shown in Figure 7. The
assignments of various bands and
peaks made in this study are in
reasonable agreement with those
reported in the literature for similar
Research and Innovation
Non-destructive Radioactive Tracer Technique in Evaluation of Photo- degraded Polystyrene Based Nuclear Grade Ion Exchange Material ı Pravin U. Singare
atw Vol. 66 (2021) | Issue 5 ı September
functional groups. In the FTIR
spectrum of fresh resin, the sharp
strong broad band was observed at
3366 cm -1 corresponding to the
vibration of O-H bond of the water or
the quaternary ammonium group
(R 4- N + ). This may be due to the
moisture content of the fresh resins.
The sharp band between 1380-
1349 cm -1 was for -C-N stretching
while a variable absorption bands
between 1633-1614 cm -1 was due to
the stretching vibrations of -C=C- of
alkenes group. The weak band at
3031 cm -1 was the characteristic
stretching band for aromatic ring. A
moderate band at 2925 cm -1 was due
to the C-H stretching band for -CH 2
group. A moderate and sharp band at
1416 cm -1 and 1470 cm -1 was due to
the -C-H bending bands for -CH 2
group. The variable band at 1511 cm -1
was the -C=C- stretching for aromatic
ring, the sharp band at 828 cm -1 and
moderate band at 705 cm -1 was the
characteristic bands of p-substituted
and o-substituted aromatic rings.
Comparison of IR spectrum of fresh
resin (Figure 7) and photo-degraded
resin (Figures 8 and 9) indicate
disappearance of characteristic -C-N
stretching band at 1349 cm -1 , -C-H
stretching band at 3031 cm -1 for
aromatic ring and a single band at
1614 cm -1 for -C=C- stretching in
alkenes.
| Fig. 7.
FTIR Spectrum of fresh Indion GS 300 resin.
| Fig. 8.
FTIR Spectrum of λ 284 photo-degraded Indion GS 300 resin.
RESEARCH AND INNOVATION 59
3.5.2 SEM study of fresh and
photo-degraded Indion GS
300 resin
The SEM image of fresh ion exchange
resins Indion GS 300 was taken to
examine its surface morphology. The
Figure 10(a) showed the surface
morphology of fresh Indion GS 300
resins which indicate its plane spherical
structure having smooth surface.
The SEM image of λ 384 and λ 284
photo-degraded Indion GS 300 resin
showed large cracks on the plane
spherical surface of the resin (Figures
10b and 10c). The SEM image of λ 384
photo-degraded resin show hair cracks
on the surface (Figure 10b). Whereas,
in case of λ 284 photo- degraded resin,
the completely broken surface with
large cracks were observed (Figure
10c), indicating higher photo-degradation
effect as compared to that of
the fresh and λ 384 photo-degraded
resin (Figures 10a and 10b).
Conclusion
In recent years, the industrial application
of polymeric resin materials has
increased considerably but it is now
well established that these materials
| Fig. 9.
FTIR Spectrum of λ 384 photo-degraded Indion GS 300 resin.
undergo rapid photo-degradation
when exposed to solar UV radiations.
The photo-degradation of resin materials
is one of the most serious
problems associated with an organic
based resin. Among the solar UV
radiations, most harmful are the high
energetic UV-B radiations (280 to
315 nm) in comparison to UV-A
radiations (315 to 400 nm) which are
of less energy. The polymeric resin
material Indion GS 300 in the present
study after exposure to UV radiation
of wavelength 284 and 384nm was
studied for the percentage isotopic ion
uptake, reaction kinetics and reaction
thermodynamics. The results of the
present investigation indicate that
isotopic ion uptake reaction rate
(min -1 ), percentage of isotopic ion
uptake are greatly affected for the
reactions performed by using λ 284 and
λ 384 photo degraded Indion GS 300
resin as compared to that of fresh
Indion GS 300 resin. The increase
in thermodynamic parameters like
Research and Innovation
Non-destructive Radioactive Tracer Technique in Evaluation of Photo- degraded Polystyrene Based Nuclear Grade Ion Exchange Material ı Pravin U. Singare
atw Vol. 66 (2021) | Issue 5 ı September
RESEARCH AND INNOVATION 60
| Fig. 10a.
SEM image of fresh Indion GS 300 resin.
energy of activation (kJ.mol -1 ),
enthalpy of activation (kJ.mol -1 ), free
energy of activation (kJ.mol -1 ) and
entropy of activation (kJ.K-1mol -1 )
calculated for the isotopic ion uptake
reactions using the fresh, λ 384 and λ 284
photo degraded Indion GS 300 resin
give an indication that decrease in
wavelength of UV radiations has
catastrophic effect on the resin
resulting in less thermodynamic
feasibility of the isotopic ion uptake
reactions.
Acknowledgement
The author is thankful to Professor
Dr. R.S. Lokhande (Retired) for his
valuable help and support by providing
the required facilities so as
to carry out the experimental work
in Radiochemistry Laboratory, Department
of Chemistry, University
of Mumbai, Vidyanagari, Mumbai
-400 058.
References
1. C. Srinivas, G. Sugilal and P. K. Wattal, Management of Spent
Organic Ion-Exchange Resins by Photochemical Oxidation.
WM’03 Conference, Tucson, Arizona (USA), February 23-27, 2003.
2. G. Wypych, Handbook of material weathering, 4 th edn.
Chemtec Publishing, Toronto, p 211 (2008).
3. H. Zweifel, In book: Stabilization of polymeric materials.
Springer-Verlag Berlin Heidelberg (1998).
4. M. Strlic, and J. Kolar, Aging and stabilization of papers.
Distributed by the National and university Library, Turjaska 1,
1000 Slovenia (2005).
5. J. Goldshtein and S. Margel, Synthesis and characterization of
polystyrene/2(5-chloro-2H-benzotriazole-2-yl)-6-(1, 1-dimethylethyl)-4-methyl-phenol
composite microspheres of narrow size
distribution for UV irradiation protection. Colloid Polym Sci 289,
1863–1874 (2011).
6. J. Pospisil and S. Nespurek, Addcon World conference,
Cologne, Germany, 17–18 Oct 2006.
7. W. Schnabel, Polymer degradation: principle and practical
applications. Chapter 14. München: Hanser International ;
New York (1981).
8. A. S. Maxwell, W. R. Broughton, G. Dean and G. D. Sims.
Review of accelerated ageing methods and lifetime prediction
techniques for polymeric materials. NPL Report DEPC MPR
016, National Physical Laboratory, Teddington, Middlesex,
ISSN 1744-0270 (2005).
9. L.Valkoa, E. Klein, P. Kovarik, T. Bleha and P. Simon, Kinetic
study of thermal dehydrochlorination of poly (vinyl chloride)
in the presence of oxygen: III. Statistical thermodynamic
interpretation of the oxygen catalytic activity. Eur. Polym. J. 37,
1123–1133 (2001).
| Fig. 10b.
SEM image of λ 384 photo-degraded Indion
GS 300 resin.
10. R.R. Mohamed, Photostabilization of polymers. S. Palsule (ed),
In book: Encyclopedia of Polymers and Composites,
Springer-Verlag Berlin Heidelberg (2015).
DOI 10.1007/978-3-642-37179-0_74-1
11. F.A. Bottino, A.R. Cinquegrani, G. Pasquale, L.L. Di and
A. Pollicino, Chemical modification, mechanical properties and
surface photooxidation of films of polystyrene. Polym. Test 12,
405–411(2003).
12. B.G. Kumar, R.P. Singh and T. Nakamura, Degradation of
carbon fiber-reinforced epoxy composites by ultraviolet
radiation and condensation. Journal of Composite Materials,
36(24), 2713-2721 (2002).
13. A.W. Signor, M.R. VanLandingham and J.W. Chin, Effect of
ultraviolet radiation exposure on vinyl ester resins:
characterization of chemical, physical, mechanical damage.
Polymer Degradation and Stability, 79(2), 359-368 (2003).
14. L.F.A. Pinto, B.E. Goi, C.C. Schmitt and M.G. Neumann.
Photodegradation of polystyrene films containing UV- visible
sensitizers. Journal of Research Updates in Polymer Science
2(1), 39–47 (2013).
15. P. Gijsman and M. Diepens, Photolysis and photooxidation in
engineering plastics. In M. C. Celina, N. C. Billingham, and
J. S. Wiggins (Eds.), Polymer degradation and performance
(pp. 287-306). (ACS Symposium Series; Vol. 1004).
Washington: American Chemical Society, (2009).
DOI: 10.1021/bk-2009-1004.ch024
16. E. Yousif and R. Haddad, Photodegradation and photostabilization
of polymers, especially polystyrene: review.
SpringerPlus, 2, Article No. 398 (2013).
17. A.N. Patange, Thermodynamics of Ion Exchange Reaction in
Predicting the Ionic Selectivity Behavior of UV Radiation
Degraded Nuclear-grade and Non-nuclear Grade Resins.
Oriental Journal of Chemistry, 34(4), 2051-2059 (2018).
18. D.D. Sood, Proceedings of International Conference on
Applications of Radioisotopes and Radiation in Industrial
Development, edited by D. D. Sood, A. V. R. Reddy, S. R. K. Iyer,
S. Gangadharan and G. Singh, BARC, Mumbai, India, p.47,
(1998).
19. P. U. Singare, Studies on kinetics and thermodynamics of ion
adsorption reactions by applications of short-lived radioactive
tracer isotopes. Ionics, 22(8), 1433-1443 (2016).
20. R.S. Lokhande and P.U. Singare, Comparative Study on Ion-
Isotopic Exchange Reaction Kinetics by Application of Tracer
Technique. Radiochim. Acta, 95(3), 173-176 (2007).
21. R.S. Lokhande, P.U. Singare and V.V. Patil, Application of Radioactive
Tracer Technique to Study the Kinetics and Mechanism
of Reversible Ion-Isotopic Exchange Reaction using Strongly
Basic Anion Exchange Resin Indion -850. Radiochemistry,
50(6), 638-641 (2008).
22. R.S. Lokhande and P.U. Singare, Comparative Study on Iodide
and Bromide Ion-Isotopic Exchange Reactions by Application
of Radioactive Tracer Technique, J.Porous Mater., 15(3),
253-258 (2008).
23. L.K. Onga, A. Kurniawana, A.C. Suwandi, C.X. Linb, X.S. Zhao
and S. Ismadji, Transesterification of leather tanning waste to
biodiesel at supercritical condition: Kinetics and thermodynamics
studies. The Journal of Supercritical Fluids, 75,
11–20 (2013).
24. V. Stavila, J. Volponi, A. M. Katzenmeyer, M. C. Dixon and
M. D. Allendorf, Kinetics and mechanism of metal-organic
framework thin film growth: systematic investigation of
HKUST-1 deposition on QCM electrodes, Chem. Sci., 3(5),
1531-1540 (2012).
| Fig. 10c.
SEM image of λ 284 photo-degraded Indion
GS 300 resin.
Author
pravin.singare@bhavans.ac.in
Pravin U. Singare
Associate Professor
(Chemistry)
Department of
Chemistry,
N.M. Institute of Science,
Bhavan’s College,
Mumbai, India
Pravin U. Singare has worked extensively on
characterization of nuclear and non-nuclear grade ion
exchange resins using radioactive tracer technique.
He is the member of Indian Society of Analytical
Scientists, National Association for Application of
Radio Isotopes and Radiation in Industry (NAARI),
Indian Nuclear Society (INS), and Indian Association
of Nuclear Chemists & Allied Scientists (IANCAS) all
from Bhabha Atomic Research Centre, (B.A.R.C.),
Anushaktinagar, Mumbai, and Indian Council of
Chemists (ICC), Agra, India.
Research and Innovation
Non-destructive Radioactive Tracer Technique in Evaluation of Photo- degraded Polystyrene Based Nuclear Grade Ion Exchange Material ı Pravin U. Singare
VGB-Standard
Water in Nuclear Power Plants with Light-Water Reactors
Part 1: Pressurised-Water Reactors. Part 2: Boiling-Water Reactors.
(formerly VGB-R 401)
Edition 2020 – VGB-S-401-00-2020-05-EN (VGB-S-401-00-2020-05-DE, German edition)
DIN A4, Print/eBook*, 92 Pages, Price for VGB-Members € 180.–, for Non-Members € 270.–, + Shipping & VAT
Almost half a century after publication of the first edition of a VGB-Guideline for the Water in Nuclear
Power Plants with Light-Water Reactors and approx. 13 years after the third edition in 2006, the task
of a renewed adaptation of the Guideline for the Water in Light-Water Reactors as VGB-Standard arises.
This VGB-Standard shall be the common basis for the operation of the plants. It provides the framework
for operating manuals or chemical manuals, but is in no way intended to replace them.
The task of these manuals is, among other things, to consider plant-specific features and to make
specifications that go beyond this VGB-Standard.
This VGB-Standard describes the water-chemical specification for the safe operation of light-water
reactors based on the material concept of the Siemens/KWU and comparable plants.
The revision takes into account, where appropriate, the knowledge and experience gained over the
last decade in the national and international environment.
VGB-Standard
for the Water in Nuclear
Power Plants with
Light-Water Reactors
Part 1: PWR
Part 2: BWR
(Formerly VGB-R 401)
VGB-S-401-00-2020-05-EN
Notice: A background paper (VGB-S-401-91-2020-05-EN) with further notes and summarised experiences will be available in July 2021.
Part 1, PWR. Contents (abbreviated)
1 Field of application
2 Definitions
2.1 General
2.2 Definition of the Action Levels for the reactor coolant circuit
2.3 Definition of the Action Levels for the water-steam cycle
2.4 Definition of the Action Areas for the water-steam cycle
2.5 Overview diagram of a PWR plant
3 Reactor coolant circuit
3.1 Fundamentals of reactor coolant chemistry
3.2 Explanations
3.3 Specifications
3.4 Special treatment methods
4 Water-steam cycle
4.1 Fundamentals of the chemistry of the water-steam cycle
4.2 Control parameters for start-up operation
4.3 Diagnostic parameters for start-up operation
4.4 Control parameters for continuous operation
4.5 Integral control parameters for continuous operation
4.6 Diagnostic parameters for continuous operation
4.7 Diagnostic parameters for make-up water
4.8 Specification of the media of the water-steam cycle
4.9 Special treatment methods and measurements
5 Literature
6 List of abbreviations
7 Annex 1: Overview main cooling circuit
8 Annex 2: Overview water/steam cycle
Part 2, BWR. Contents (abbreviated)
1 Field of application
2 Definitions
2.1 Control parameters
2.2 Diagnostic parameters
2.3 Normal operating values
2.4 Tolerable range
2.5 Action Levels
3 Fundamentals of chemistry in the reactor system and
in the water-steam cycle
3.1 Total overview
3.2 Reasons for the high chemical demands requirements on
the water-steam cycle including reactor water
3.3 Explanation of the chemical parameters for the reactor water and the water-steam cycle during plant operation
3.4 Explanation of the chemical parameters for reactor water in cold condition (< 100 °C) and for start-up readiness,
as well as for feed water before start-up
4 Specification values for reactor water and water/steam cycle
5 Specification values for auxiliary and secondary systems
6 Literature
* Access for eBooks (PDF files) is included in the membership fees for Ordinary Members (operators, plant owners) of VGB. www.vgb.org/vgbvs4om
VGB PowerTech Service GmbH
Verlag technisch-wissenschaftlicher Schriften
Deilbachtal 173 | 45257 Essen | Germany
Fon: +49 201 8128-200 | Fax: +49 201 8128-302 | E-Mail: mark@vgb.org | www.vgb.org/shop
atw Vol. 66 (2021) | Issue 5 ı September
62
NEWS
Top
Nuclear making Europe
fit for 55
(nei) FORATOM welcomes the
Commission’s Fit for 55 package and
fully supports all proposals which aim
to reduce CO 2 emissions in line with
the Climate Law and Paris Agreement.
Indeed, the bar has been set very high
as it will apply to a broad range of
sectors including industry, buildings
and transport.
“Achieving this target will not be
easy – many aspects need to be taken
into consideration to ensure that, in
the race to decarbonisation, other
problems do not arise”, states Yves
Desbazeille, FORATOM Director
General.
For example:
p How will be this transition
financed?
p Will we have enough low-carbon
energy to meet our needs?
p How can we ensure that industries
are able to decarbonise their
manufacturing processes whilst
remaining competitive?
p And how can we mitigate potential
social impacts (eg job losses,
energy poverty)?
“Nuclear has a key role to play in
this transition, together with other
low- carbon technologies” adds Mr
Desbazeille. “It is a low-carbon source
of energy, thus helping European
achieve its decarbonisation targets. It
is also affordable and available 24/7,
two key attributes when it comes to
finding competitive solutions for
energy-intensive industries in Europe”.
The nuclear sector remains committed
to working with the EU and
supporting technology neutral policies
which will help us achieve these
ambitious goals. Furthermore, and as
highlighted in the latest IEA and
OECD NEA report entitled ‘Projected
Costs of Generating Electricity 2020’,
the long-term operation of nuclear
power plants remains the cheapest
source of electricity across the board.
Therefore, prolonging the existing
fleet would be the best way of
achieving the 2030 targets in an
affordable manner.
| www.foratom.org (211711803)
NEI: Advanced Nuclear will
Balance Energy Supply and
Demand
(nei) As we prepare for a decarbonized
grid with more wind and solar,
it’s critical to prepare a way to balance
energy supply, which varies over the
course of the day, with demand.
Demand varies too, but on a different
schedule.
Balancing supply with demand has
always been essential to ensuring a
reliable grid. Energy use varies from
minute to minute, driven by people’s
use of air conditioning, heating,
lighting and other devices. Today, the
energy system meets those changes by
shifting how much fossil fuel it is
burning.
In solar intensive locations like
California, copious energy from the
sun at midday leads utilities to shut
Operating Results May 2021
Plant name Country Nominal
capacity
Type
gross
[MW]
net
[MW]
Operating
time
generator
[h]
Energy generated, gross
[MWh]
Month Year Since
commissioning
Time availability
[%]
Energy availability
[%] *) Energy utilisation
[%] *)
Month Year Month Year Month Year
OL1 Olkiluoto 1) BWR FI 910 880 484 432 112 2 945 004 279 979 721 65.04 89.37 62.85 87.77 63.13 88.35
OL2 Olkiluoto 1,4) BWR FI 910 880 378 347 351 3 015 004 269 917 726 50.81 89.90 50.58 89.81 50.75 90.45
KCB Borssele 1,4) PWR NL 512 484 499 223 019 1 671 972 173 740 769 58.20 91.41 58.22 91.42 58.23 90.16
KKB 1 Beznau 1,7) PWR CH 380 365 433 159 742 1 260 683 134 472 069 58.20 91.42 56.33 90.83 55.97 91.48
KKB 2 Beznau 6,7) PWR CH 380 365 744 282 009 1 377 536 141 753 837 100.00 100.00 100.00 100.00 99.78 100.08
KKG Gösgen 1,2,7) PWR CH 1060 1010 509 534 805 3 552 518 334 439 107 68.35 92.52 67.92 91.95 67.81 92.50
CNT-I Trillo 3) PWR ES 1066 1003 360 380 667 3 129 396 267 153 244 48.44 82.34 48.36 82.23 47.69 80.56
Dukovany B1 PWR CZ 500 473 744 366 520 1 289 586 120 934 025 100.00 72.43 99.45 71.38 98.53 71.19
Dukovany B2 PWR CZ 500 473 744 364 274 1 795 247 116 407 162 100.00 100.00 99.61 99.82 97.92 99.10
Dukovany B3 PWR CZ 500 473 660 314 737 1 731 972 115 092 529 88.71 97.68 87.87 97.37 84.61 95.61
Dukovany B4 PWR CZ 500 473 744 364 171 1 136 707 115 702 608 100.00 63.92 99.51 63.12 97.90 62.75
Temelin B1 PWR CZ 1080 1030 230 208 026 2 421 505 131 992 795 30.91 62.57 25.68 61.46 25.84 61.77
Temelin B2 PWR CZ 1080 1030 744 810 191 3 977 937 129 566 841 100.00 100.00 99.93 99.98 100.27 101.10
Doel 1 PWR BE 454 433 499 227 917 1 597 240 141 611 081 67.08 93.24 66.70 93.08 65.79 94.65
Doel 2 2) PWR BE 454 433 744 349 212 1 320 047 139 930 112 100.00 78.03 99.98 77.32 100.29 77.90
Doel 3 PWR BE 1056 1006 744 796 408 3 819 505 275 031 816 100.00 99.22 100.00 98.92 100.74 99.25
Doel 4 PWR BE 1084 1033 744 815 217 3 962 050 281 322 040 100.00 100.00 99.97 99.99 99.60 99.35
Tihange 1 PWR BE 1009 962 744 737 163 3 660 915 311 527 890 100.00 100.00 98.54 99.53 98.32 100.38
Tihange 2 PWR BE 1055 1008 395 310 332 2 621 020 268 324 837 53.02 74.46 39.44 68.46 39.44 69.04
Tihange 3 PWR BE 1089 1038 744 797 031 3 908 177 290 561 835 100.00 100.00 99.97 99.98 98.88 99.60
Plant name
Type
Nominal
capacity
gross
[MW]
net
[MW]
Operating
time
generator
[h]
Energy generated, gross
[MWh]
Time availability
[%]
Energy availability Energy utilisation
[%] *) [%] *)
Month Year Since Month Year Month Year Month Year
commissioning
GKN-II Neckarwestheim 4) DWR 1480 1410 744 1 013 850 5 027 350 356 378 894 100.00 100.00 100.00 99.98 97.51 99.39
KBR Brokdorf DWR 1406 1335 744 1 019 287 4 967 761 376 231 090 100.00 100.00 99.95 99.96 92.37 92.45
KKE Emsland 1,2) DWR 1430 1360 348 479 085 4 474 670 373 485 371 46.83 88.98 46.20 88.79 45.80 87.90
KKI-2 Isar DWR 1344 1288 744 1 062 814 5 302 849 382 731 892 100.00 100.00 100.00 99.99 95.82 98.29
KRB C Gundremmingen SWR 1485 1410 744 999 351 4 891 476 355 369 242 100.00 100.00 100.00 99.90 99.27 99.77
KWG Grohnde DWR 1400 1310 744 1 003 789 4 078 261 402 838 610 100.00 82.37 100.00 81.99 93.79 78.32
News
atw Vol. 66 (2021) | Issue 5 ı September
down their fossil-fired generation. As
the sun goes down, people come home
from work and turn on air conditioning
and TVs and start using appliances
like microwaves for dinner. As
demand increases, solar disappears.
Plain and simple, demand
threatens to rise faster than the fossilfueled
system can accommodate.
The solution is to store energy for
when it’s needed most, and that’s
where advanced nuclear technologies
have a strong role to play. These
nuclear innovations must be developed
in parallel with increased
deployment of wind and solar,
building a foundation of always-on,
carbon-free energy that can also help
maintain the instantaneous balance
between supply and demand.
Four of the newest advanced
nuclear designs are being prepared to
store energy, using innovative ways to
run a nuclear reactor continuously
while varying the electricity output.
When the reactor’s production of heat
exceeds the demand for electricity, the
excess energy is stored as heat. When
demand for electricity is higher than
what the reactor is producing, the
extra heat is drawn from the storage
tank and turned into electricity.
An example of this design is
the Natrium project, a partnership
between Bill Gates’s TerraPower and
GEHitachi that is backed by the United
States Department of Energy.
Natrium is choosing among four sites
of soon-to-be-retired coal plants in
Wyoming for a plant that can vary its
output from 100 megawatts to 500
megawatts.
TerraPower also has a design for a
molten chloride reactor that would
store energy as heat. Moltex Energy
and Terrestrial Energy also have reactors
in design that would use a giant
tank filled with salt or rocks as a bank
for depositing or withdrawing heat.
The concept keeps the reactor running
at full output almost all the time,
while creating heat storage and saving
the energy for when it’s most valuable
and needed.
While other options exist to store
energy, advanced nuclear technologies
are critical to this effort as they
offer both an efficient and environmentally
friendly energy storage
option. When compared to batteries
for example, heat storage is cheaper
and doesn’t require scarce minerals.
Policymakers and developers are
smartly investing in new innovative
nuclear designs. Their investments
have the potential to offer tremendous
returns with new designs churning
out the reliable, carbon-free energy
necessary to reach our climate goals,
while also helping match production
with demand by efficiently storing
energy as heat.
Advanced reactors will be essential
in multiple ways to our future energy
grid, offering unique capabilities to
complement wind and solar technologies
and demonstrating vital
inno vation to match our energy needs.
| www.nei.org (211711749)
*) Net-based values
(Czech and Swiss nuclear
power plants
gross-based)
1) Refueling
2) Inspection
3) Repair
4) Stretch-out-operation
5) Stretch-in-operation
6) Hereof traction supply
7) Incl. steam supply
BWR: Boiling
Water Reactor
PWR: Pressurised Water
Reactor
Source: VGB
63
NEWS
Operating Results June 2021
Plant name Country Nominal
capacity
Type
gross
[MW]
net
[MW]
Operating
time
generator
[h]
Energy generated, gross
[MWh]
Month Year Since
commissioning
Time availability
[%]
Energy availability
[%] *) Energy utilisation
[%] *)
Month Year Month Year Month Year
OL1 Olkiluoto BWR FI 910 880 720 654 062 3 599 066 280 633 783 100.00 91.13 99.48 89.71 98.74 90.08
OL2 Olkiluoto 1) BWR FI 910 880 267 225 370 3 240 374 270 143 096 37.13 81.15 34.59 80.65 34.02 81.10
KCB Borssele 1) PWR NL 512 484 0 0 1 671 972 173 740 769 0 76.26 -900 -73 0 75.21
KKB 1 Beznau 6,7) PWR CH 380 365 720 270 721 1 531 404 134 742 790 100.00 92.84 100.00 92.35 98.92 92.72
KKB 2 Beznau 7) PWR CH 380 365 720 268 898 1 646 434 142 022 735 100.00 100.00 100.00 100.00 98.26 99.78
KKG Gösgen 1,2,7) PWR CH 1060 1010 143 120 843 3 673 361 334 559 950 100.00 93.76 16.15 79.38 15.83 79.79
CNT-I Trillo 1,2) PWR ES 1066 1003 174 154 854 3 284 250 267 308 098 24.21 72.70 19.76 71.87 19.79 70.48
Dukovany B1 PWR CZ 500 473 720 349 270 1 638 855 121 283 294 100.00 77.00 100.00 76.12 97.02 75.47
Dukovany B2 PWR CZ 500 473 720 345 231 2 140 479 116 752 393 100.00 100.00 100.00 99.85 95.90 98.57
Dukovany B3 PWR CZ 500 473 0 0 1 731 972 115 092 529 0 81.49 0 81.23 0 79.76
Dukovany B4 PWR CZ 500 473 720 353 561 1 490 268 116 056 169 100.00 69.91 99.92 69.22 98.21 68.63
Temelin B1 PWR CZ 1080 1030 720 775 720 3 197 225 132 768 515 100.00 68.78 99.91 67.83 99.57 68.04
Temelin B2 PWR CZ 1080 1030 552 581 844 4 559 781 130 148 685 76.67 96.13 74.39 95.74 74.41 96.68
Doel 1 2) PWR BE 454 433 250 102 737 1 699 977 141 713 819 34.67 83.53 30.87 82.77 30.46 84.01
Doel 2 PWR BE 454 433 720 331 796 1 651 843 140 261 908 100.00 81.67 99.96 81.07 98.45 81.31
Doel 3 PWR BE 1056 1006 720 753 303 4 572 808 275 785 119 100.00 99.35 99.01 98.93 98.53 99.13
Doel 4 PWR BE 1084 1033 720 778 772 4 740 822 282 100 811 100.00 100.00 100.00 99.99 98.29 99.18
Tihange 1 PWR BE 1009 962 720 704 797 4 365 712 312 232 687 100.00 100.00 99.91 99.59 97.08 99.84
Tihange 2 PWR BE 1055 1008 720 735 259 3 356 279 269 060 096 100.00 78.69 99.15 73.55 97.64 73.78
Tihange 3 PWR BE 1089 1038 720 761 960 4 670 136 291 323 795 100.00 100.00 99.96 99.98 97.61 99.27
Plant name
Type
Nominal
capacity
gross
[MW]
net
[MW]
Operating
time
generator
[h]
Energy generated, gross
[MWh]
Time availability
[%]
Energy availability Energy utilisation
[%] *) [%] *)
Month Year Since Month Year Month Year Month Year
commissioning
GKN-II Neckarwestheim 1,2,4) DWR 1480 1410 256 309 100 5 336 450 356 687 994 35.56 89.32 35.56 89.30 30.48 87.97
KBR Brokdorf DWR 1406 1335 720 1 023 756 5 991 517 377 254 846 100.00 100.00 100.00 99.97 95.87 93.02
KKE Emsland DWR 1430 1360 720 992 975 5 467 645 374 478 346 100.00 90.81 100.00 90.65 98.07 89.59
KKI-2 Isar DWR 1344 1288 720 995 880 6 298 729 383 727 772 100.00 100.00 100.00 99.99 92.60 97.34
KRB C Gundremmingen SWR 1485 1410 720 932 684 5 824 160 356 301 926 100.00 100.00 98.02 99.59 95.64 99.08
KWG Grohnde DWR 1400 1310 720 967 132 5 045 393 403 805 742 100.00 85.29 99.63 84.91 93.30 80.80
News
atw Vol. 66 (2021) | Issue 5 ı September
64
NEWS
US: $1.2 Trillion Infrastructure
Bill Includes Plans for New
Reactors and Credits for
Existing Plants
(nucnet) President Joe Biden’s $1.2tn
infrastructure bill, passed this week by
the Senate, lays out plans for the
development of new nuclear reactor
technology and a credit programme
for existing reactors that face closure
because of economic reasons.
The bill, which still needs approval
from the House of Representatives,
says energy secretary Jennifer Granholm
will submit a report describing
how the Department of Energy could
improve energy resilience and reduce
carbon emissions with the use of small
modular reactors and microreactors.
The report should be submitted to
the Senate’s committee on energy and
natural resources and the House of
Representatives’ committees on energy
and commerce, and science, space and
technology not later than 180 days
after the legislation becomes law.
The bill says the DOE will offer
financial and technical assistance to
entities to conduct feasibility studies
to identify suitable locations for the
deployment of SMRs, microreactors
and advanced reactors in isolated
communities.
The bill includes a proposal to
develop at least one regional clean
hydrogen hub to demonstrate the
production of clean hydrogen from
nuclear energy.
Another key element of the bill for
the nuclear industry is its call for a
credit programme for commercial
nuclear reactors. It calls on Ms
Granholm to evaluate nuclear reactors
that are projected to be permanently
shut down because of economic factors
and to allocate credits to those that
qualify.
In order to qualify for credits, the
owner or operator of a nuclear plants
will need to file an application with
the DOE.
The bill says the application will
need to incorporate information
including “the average projected
annual operating loss in dollars per
megawatt-hour, inclusive of the cost of
operational and market risks, expected
to be incurred by the nuclear reactor
over the four-year period for which
credits would be allocated”. The application
should also include an estimate
of the potential incremental air pollutants
that would result if the nuclear
reactor were to cease operations.
Press reports in the US have said
the legislation will come too late to
prevent the Byron and Dresden
nuclear power plants in Illinois from
being shut down this year. Operator
Exelon said proposed Illinois legislation,
separate from the federal infrastructure
bill, that would provide state
subsidies is “the only solution that can
pass in time to provide the certainty
we need”.
Exelon, the nation’s largest operator
of nuclear plants, has filed plans to
decommission its Byron and Dresden
units, citing a lack of action from state
lawmakers on clean energy legislation
that would help save the facilities. The
company said that without a legislative
solution, these same market
inequities will also force it to close its
Braidwood and LaSalle nuclear facilities
sometime in the next few years.
The US feet of 93 nuclear plants,
which provides about 20 % of the
nation’s electricity, have been facing
revenue shortfalls because of declining
energy prices and market rules
that the nuclear industry says favour
fossil fuel plants.
The Washington-based Nuclear
Energy Institute has said a combination
of policy and economic factors
has led to the premature closure of
several highly reliable plants with
high capacity factors and relatively
low generating costs.
It said additional plants will face
the prospect of early closure unless
policies that value the benefits of
nuclear energy are put in place.
Europe
United Nations: Europe Needs
‘Consistent Policies And Clear
Market Frameworks’ For New
Nuclear
(nucnet) Decarbonising energy is a
significant undertaking that will
require deployment of all available
low-carbon technologies, including
nuclear power, but governments must
provide positive, long-term policy
signals for new reactor development,
according to a new technology brief
from the United Nations Economic
Commission for Europe (UNECE)*.
The brief says consistent policies
and clear market frameworks will enable
investment in new nuclear power
projects and support stable supply
chains.
In an apparent reference to
Europe’s sustainable finance taxonomy,
it says “green finance classifications
should be based on scientific
and technology-neutral methodologies”.
Multilateral banks and
international finance institutions
should consider nuclear projects as
part of their “sustainable lending activities”.
The sustainable finance taxonomy
is a package of regulations that
governs investment in activities that
the EU says are environmentally
friendly.
The European commission decided
not to include nuclear energy in the
taxonomy, which entered into force
last summer, but said it would include
it under a complementary delegated
act in 2021. The act would carry the
technical screening criteria for determining
the conditions under which
nuclear could qualify as contributing
to sustainability and climate change
mitigation.
The commission asked the Joint
Research Centre, its scientific expert
arm, to assess nuclear power against
the taxonomy’s “do no significant
harm” criteria. When the report was
ready in April, the commission asked
two other expert groups – the Euratom
Article 31 expert group on radiation
protection and the scientific committee
on health, environmental and
emerging risks (Scheer) – to review
the JRC’s report and provide additional
opinions.
The EC then said it would need to
take into account the three reports
before it makes a decision about the
inclusion of nuclear in delegated acts
in the taxonomy. Delegated acts are
legally-binding rules which will
supplement the taxonomy.
The UNECE brief calls for governments
to accelerate the development
and deployment of small modular
reactors and advanced reactor technologies,
with technical, financial and
regulatory support “essential” for the
deployment and commercialisation of
these new nuclear technologies.
International harmonisation of
licensing frameworks is also needed if
new nuclear projects are to succeed.
The policy brief also says securing
the long-term operation of existing
nuclear plants will avoid unnecessary
CO 2 emissions and decrease the costs
of Europe’s energy transition.
UNECE, set up in 1947, is one of five
regional commissions of the United
Nations. Its main aim is to promote
pan-European economic integration.
UNECE includes 56 member States in
Europe, North America and Asia.
News
atw Vol. 66 (2021) | Issue 5 ı September
Uranium
Prize range: Spot market [USD*/lb(US) U 3O 8]
140.00
) 1
Uranium prize range: Spot market [USD*/lb(US) U 3O 8]
140.00
) 1
120.00
120.00
65
100.00
100.00
80.00
80.00
60.00
40.00
20.00
Yearly average prices in real USD, base: US prices (1982 to1984) *
60.00
40.00
20.00
NEWS
0.00
1980
Jan. 2009
Jan. 2010
1985
Jan. 2011
Jan. 2012
* Actual nominal USD prices, not real prices referring to a base year. Year
1990
Jan. 2013
1995
Jan. 2014
Jan. 2015
2000
Jan. 2016
2005
Jan. 2017
Jan. 2018
2010
Jan. 2019
2015
Jan. 2020
2020
2021
Year
* Actual nominal USD prices, not real prices referring to a base year. Sources: Energy Intelligence, Nukem; Bild/Figure: atw 2021 * Actual nominal USD prices, not real prices referring to a base year. Year
Sources: Energy Intelligence, Nukem; Bild/Figure: atw 2021
| Uranium spot market prices from 1980 to 2021 and from 2009 to 2021. The price range is shown.
In years with U.S. trade restrictions the unrestricted uranium spot market price is shown.
Separative work: Spot market price range [USD*/kg UTA]
Conversion: Spot conversion price range [USD*/kgU]
180.00
26.00
) 1 ) 1
24.00
160.00
22.00
140.00
120.00
100.00
80.00
60.00
40.00
20.00
0.00
Jan. 2021
Jan. 2022
Sources: Energy Intelligence, Nukem; Bild/Figure: atw 2021
0.00
Jan. 2009
Jan. 2010
Jan. 2011
Jan. 2012
Jan. 2013
Jan. 2014
* Actual nominal USD prices, not real prices referring to a base year. Year
| Separative work and conversion market price ranges from 2009 to 2021. The price range is shown.
)1
In December 2009 Energy Intelligence changed the method of calculation for spot market prices. The change results in virtual price leaps.
* Actual nominal USD prices, not real prices referring to a base year
Sources: Energy Intelligence, Nukem; Bilder/Figures: atw 2021
20.00
18.00
16.00
14.00
12.00
10.00
8.00
6.00
4.00
2.00
0.00
Jan. 2009
Jan. 2010
Jan. 2011
Jan. 2012
Jan. 2013
Jan. 2014
Jan. 2015
Jan. 2015
Jan. 2016
Jan. 2016
Jan. 2017
Jan. 2017
Jan. 2018
Jan. 2018
Jan. 2019
Jan. 2019
Jan. 2020
Jan. 2020
Jan. 2021
Jan. 2021
Jan. 2022
Jan. 2022
Sources: Energy Intelligence, Nukem; Bild/Figure: atw 2021
Market data
(All information is supplied without
guarantee.)
Nuclear Fuel Supply
Market Data
Information in current (nominal)
U.S.-$. No inflation adjustment of
prices on a base year. Separative work
data for the formerly “secondary
market”. Uranium prices [US-$/lb
U 3 O 8 ; 1 lb = 453.53 g; 1 lb U 3 O 8 =
0.385 kg U]. Conversion prices [US-$/
kg U], Separative work [US-$/SWU
(Separative work unit)].
2017
p Uranium: 19.25–26.50
p Conversion: 4.50–6.75
p Separative work: 39.00–50.00
2018
p Uranium: 21.75–29.20
p Conversion: 6.00–14.50
p Separative work: 34.00–42.00
2019
p Uranium: 23.90–29.10
p Conversion: 13.50–23.00
p Separative work: 41.00–52.00
2020
January to March 2020
p Uranium: 24.10–27.40
p Conversion: 21.50–23.50
p Separative work: 45.00–53.00
April 2020
p Uranium: 27.50–34.00
p Conversion: 21.50–23.50
p Separative work: 45.00–52.00
May 2020
p Uranium: 33.50–34.50
p Conversion: 21.50–23.50
p Separative work: 48.00–52.00
June 2020
p Uranium: 33.00–33.50
p Conversion: 21.50–23.50
p Separative work: 49.00–52.00
July 2020
p Uranium: 32.50–33.20
p Conversion: 21.50–23.50
p Separative work: 50.50–53.50
August 2020
p Uranium: 30.50–32.25
p Conversion: 21.50–23.50
p Separative work: 51.00–54.00
September 2020
p Uranium: 29.90–30.75
p Conversion: 21.00–22.00
p Separative work: 51.00–54.00
October 2020
p Uranium: 28.90–30.20
p Conversion: 21.00–22.00
p Separative work: 51.00–53.00
November 2020
p Uranium: 28.75–30.25
p Conversion: 19.00–22.00
p Separative work: 51.00–53.00
December 2020
p Uranium: 29.50–30.40
p Conversion: 19.00–22.00
p Separative work: 51.00–53.00
January 2021
p Uranium: 29.50–30.50
p Conversion: 19.00–22.00
p Separative work: 51.00–53.00
February 2021
p Uranium: 28.75–29.10
p Conversion: 20.00–22.00
p Separative work: 52.00–54.00
March 2021
p Uranium: 27.25–31.00
p Conversion: 20.00–22.00
p Separative work: 52.00–55.00
April 2021
p Uranium: 28.40–31.00
p Conversion: 19.00–21.00
p Separative work: 51.00–54.00
May 2021
p Uranium: 29.15–31.35
p Conversion: 19.50–21.50
p Separative work: 52.00–54.00
June 2021
p Uranium:31.00–32.50
p Conversion: 19.50–21.50
p Separative work: 54.00–56.00
| Source: Energy Intelligence
www.energyintel.com
News
atw Vol. 66 (2021) | Issue 5 ı September
66
NUCLEAR TODAY
John Shepherd
is editor-in-chief
of the online publication
New Energy 360 &
World Battery News.
Sources:
IPCC report summary:
https://bit.ly/3AtOFh9
MEPs letter to EC:
https://bit.ly/3xDe2eB
As Science Turns Up the Heat on Climate Change Sceptics,
How Long Before the Nero-like Nuclear Deniers Must Change
Their Tune?
The loss of life and catastrophic impact of the floods that swept through Europe earlier this year, coupled with the horrific
scenes of wildfires raging in southern Europe, the US and elsewhere, have been the starkest wake-up call to date of the
effects of climate change.
Climate change deniers have still been out there, a little bit
like the apocryphal account of Nero, the former emperor of
Rome, “fiddling” while the city was engulfed by a near
week-long fire.
But what cannot be denied is the science telling us that
human activities, including the generation of greenhouse
gases (GHGs), are contributing to increasing climatic
devastation.
As I submitted this article to the editor, the latest report
from the UN’s Intergovernmental Panel on Climate Change
(IPCC) stated: “Climate change is intensifying the water
cycle. This brings more intense rainfall and associated
flooding, as well as more intense drought in many regions.”
The report added that emissions of GHGs from human
activities “are responsible for approximately 1.1 °C of
warming since 1850-1900”. Averaged over the next 20 years,
the IPCC’s report said global temperature is expected to
reach or exceed 1.5 °C of warming.
The report also noted that weather conducive to wildfires
could be traced to human influence and gave new estimates
of the chances of crossing the global warming level of 1.5 °C
in the next decades, finding that “unless there are immediate,
rapid and large-scale reductions in greenhouse gas
emissions, limiting warming to close to 1.5 °C or even 2 °C
will be beyond reach”.
Energy production accounts for two-thirds of total greenhouse
gas, so efforts to reduce emissions and mitigate climate
change must include this sector and nuclear power can be a
massive part of the solution – as those involved in the industry
should never tire of reminding themselves and others.
Nuclear plants produce almost no GHGs or air pollutants
during their operation. This edition of atw is focused on
uranium and the nuclear fuel cycle, so with that in mind, it’s
worth reminding ourselves that over the course of its life
cycle, nuclear produces about the same amount of carbon
dioxide-equivalent emissions per unit of electricity as wind,
and one-third of the emissions per unit of electricity when
compared with solar.
Sadly, even nuclear has an even bigger hurdle to
overcome – that most exasperating of human activity that
sometimes stands in the way of fighting climate change: a
combination of environmental and political dogma.
Let’s take Germany, where federal elections are due in
September 2021, as an example.
Long before flooding wrecked communities along the
Rhine and Ahr rivers, Annalena Baerbock, the Greens’
candidate seeking to replace outgoing chancellor Angela
Merkel, thrust the issue of climate change into the election
campaign.
Baerbock told the German news magazine, Der Spiegel:
“Germany has been fortunate for decades in suffering
relatively few natural catastrophes, however, that’s meant
that the disaster protection measures haven’t been
sufficiently developed.”
I don’t know if the would-be Green chancellor was asked
about her party’s decades of opposition to nuclear energy
and whether that had had an impact on the environment,
but I’m guessing not.
So what about other potential German leaders heading to
the ballot box? German vice-chancellor and finance minister,
Olaf Scholz, the Social Democrats’ candidate to replace
Merkel, pledged a “billions-strong recovery programme” and
said he wanted to see changes to the country’s disaster
prevention plans and climate protection measures. But as I
write he too had yet to spell out the details.
Legislation that came into force in Germany in 2002
limited the operating lifetimes of German reactor units to
about 32 years. The politically-inspired move aimed to
ensure the gradual phase-out of the use of nuclear power in
the country.
Merkel, a former research scientist, said early on in her
chancellorship that she personally was against the
phase-out.
Meanwhile, a group of five EU Member States, led by
Germany, have written to the European Commission, asking
for nuclear energy to remain excluded from the EU
Taxonomy on Sustainable Finance – the classification system
to establish a list of environmentally-sustainable economic
activities.
The letter was signed, Nero-like, by the environment or
energy ministers of Austria, Denmark, Germany, Luxembourg
and Spain and pointed to “shortcomings” in a report
published last April by the Joint Research Centre (JRC).
The JRC, whose mission is to support EU policies with
independent evidence throughout the whole policy cycle,
had said nuclear energy did no more harm to human health
or the environment than any other power- producing
technology considered to be sustainable.
However, there were some who sought to keep the
embers of a sensible, science-based approach to environmental
economics alive. Nearly 100 members of the
European Parliament called on the European Commission to
follow the science and include nuclear under the taxonomy
classification system.
Their move was backed by Yves Desbazeille, the directorgeneral
of Foratom, the Brussels-based trade association for
the nuclear energy industry in Europe. He said EU member
states that wished to invest in low-carbon nuclear “should
not be prevented from doing so just because others are
politically opposed” to nuclear.
Amid all of this, it was ironic that Germany marked 60
years of generating electricity from nuclear power, after the
first power supply to the grid came from the Kahl
experimental boiling water reactor plant in June 1961. This
was the first time that electricity from nuclear energy had
been fed in and used in Germany.
Nuclear’s detractors might, if pushed, offer a grudging
acceptance to the impact of nuclear in tackling emissions,
but they would probably go on to argue that switching the
entire world’s electricity production to nuclear would still
not solve the problem of GHGs. Given that electricity
production is only one of many human activities that release
GHGs, that’s likely true.
However, the nuclear industry itself would be the first
to say its technology is not the ‘silver bullet’ needed to slay
the monstrosities wrought by climate change. Nuclear, by
all sensible accounts, should be allowed to form part of
the solution. The sooner those who seek to lead have the
courage to accept that essential truth the better for the
whole planet.
Nuclear Today
As Science Turns Up the Heat on Climate Change Sceptics, How Long Before the Nero-like Nuclear Deniers Must Change Their Tune?
ı John Shepherd
#52KT
www.kerntechnik.com
Media Partner
52 nd KERNTECHNIK
2022
Call for Papers
29 – 30 March 2022
HYPERION Hotel, Leipzig
Submit your paper now!
You are warmly invited to submit your paper to the 52 nd KERNTECHNIK 2022.
As one of Europe‘s most recognized and best established nuclear technology conferences the KERNTECHNIK,
organised by KernD and KTG, is a must-attend event for international experts and decision-makers.
Interesting sessions are awaiting you:
1. Nuclear Competence and Nuclear Safety
2. International Trends and Developments in Nuclear
3. Decommissioning and Waste Treatment
4. Interim Storage and Final Disposal
Our programme committee is looking forward
to your contribution!
For more information check:
www.kerntechnik.com/kerntechnik-en/referenten
YOUR PARTNER FOR CLEAN
AND RELIABLE ENERGY
Westinghouse is a leading infrastructure services provider to the global power
generation industry, with a deep commitment to innovation in nuclear technology.
Supporting some of the world’s most advanced commercially available plants,
Westinghouse is focused on enhancing plant safety and extending plant lifespan
by reducing outage times and maintenance costs. Backed by more than 130 years
of innovation, we are leading the way in nuclear technology, helping the world meet
growing electricity demand with clean, reliable nuclear energy.
For more information, visit:
www.westinghousenuclear.com
Westinghouse
Electric Company
@WECNuclear
Westinghouse
Electric Company
wecchinanuclear