atw 2018-02

inforum

atw Vol. 63 (2018) | Issue 2 ı February

76

ABSTRACTS | ENGLISH

WANO to Increase Focus on New Nuclear

as Industry’s Centre of Gravity Shifts

Towards Asia

NucNet | Page 78

The World Association of Nuclear Operators

(WANO) intends to focus more on new nuclear units

coming into operation around the world as the

“ centre of gravity” in the industry shifts from the US

and Europe to the Middle East and Asia. The

organisation’s chief executive officer, Peter Prozesky,

told NucNet that new-build projects in China, India,

Turkey and the United Arab Emirates are giving

WANO the opportunity to make sure those countries

start the operational life of their new units “in a very

positive way”. In supporting countries with new

units beginning operation, WANO is working more

closely with the International Atomic Energy Agency

(IAEA). One of the IAEA’s tasks is to help emerging

nuclear countries develop the infrastructure and

capability they need to have nuclear power as part of

their energy mix.

Development of High Temperature Gas

Cooled Reactor in China

Wentao Guo and Michael Schorer | Page 81

High temperature gas cooled reactor (HTGR) is one

of the six Generation IV reactor types put forward

by Generation IV International Forum (GIF) in

2002. This type of reactor has high outlet temperature.

It uses Helium as coolant and graphite as

moderator. Pebble fuel and ceramic reactor core are

adopted. Inherit safety, good economy, high generating

efficiency are the advantages of HTGR.

According to the comprehensive evaluation from

the international nuclear community, HTGR has

already been given the priority to the research and

development for commercial use. A demonstration

project of the High Temperature Reactor-Pebblebed

Modules (HTR-PM) in Shidao Bay nuclear

power plant in China is under construction. In this

paper, the development history of HTGR in China

and the current situation of HTR-PM will be introduced.

The experiences from China may be taken as

a reference by the international nuclear community.

The Liability According to § 26 of the

German Atomic Energy Act – A Wallflower?

Christian Raetzke | Page 84

According to German law, liability for damage

caused by radioactivity can arise from several

regulation. In most cases, liability under the Paris

Convention on Third Party Liability in the Field of

Nuclear Energy, which applies in the field of nuclear

power, is at the forefront of discussion. According to

§ 26 of the German Atomic Energy Act, liability is

somewhat in the shadow of the Paris Convention. It

applies to the handling of radioactivity in medicine,

research and industry (e. g. for test emitters) as well

as activities involving natural and depleted uranium

and nuclear fusion. The article outlines the basic

elements of liability under Section 26 of the German

Atomic Energy Act, which may become increasingly

important in future due to recent developments

such as the phasing out of nuclear power in

Germany.

Investigation of Conditions Inside the

Reactor Building Annulus of a PWR Plant of

KONVOI Type in Case of Severe Accidents

with Increased Containment Leakages

Ivan Bakalov and Martin Sonnenkalb | Page 85

Improvements of the implemented severe accident

management (SAM) concepts have been done in all

operating German NPPs after the Fukushima Daiichi

accidents following recommendations of the

German Reactor Safety Commission (RSK) and as a

result of the stress test being performed. The

efficiency of newly developed severe accident

management guidelines (SAMG) for a PWR KONVOI

reference plant related to the mitigation of challenging

conditions inside the reactor building (RB)

annulus due to increased containment leakages

during severe accidents have been assessed. Based

on two representative severe accident scenarios the

releases of both hydrogen and radionuclides into the

RB annulus have been predicted with different

boundary conditions. The accident scenarios have

been analysed without and with the impact of

several SAM measures (already planned or proposed

in addition), which turned out to be efficient to

mitigate the consequences. The work was done

within the frame of a research project financially

supported by the Federal Ministry BMUB.

Sensitivity Analysis of MIDAS Tests Using

SPACE Code: Effect of Nodalization

Shin Eom, Seung-Jong Oh and Aya Diab | Page 90

The nodalization sensitivity analysis for the ECCS

(Emergency Core Cooling System) bypass phenomena

was performed using the SPACE (Safety

and Performance Analysis CodE) thermal hydraulic

analysis computer code. The results of MIDAS

(Multi- dimensional Investigation in Downcomer

Annulus Simulation) test were used. The MIDAS

test was conducted by the KAERI (Korea Atomic

Energy Research Institute) for the performance

evaluation of the ECC (Emergency Core Cooling)

bypass phenomenon in the DVI (Direct Vessel

Injection) system. The main aim of this study is to

examine the sensitivity of the SPACE code results

to the number of thermal hydraulic channels

used to model the annulus region in the MIDAS

experiment. The numerical model involves three

nodalization cases (4, 6, and 12 channels) and

the result show that the effect of nodalization

on the bypass fraction for the high steam flow rate

MIDAS tests is minimal. For computational

efficiency, a 4 channel representation is recommended

for the SPACE code nodalization. For the

low steam flow rate tests, the SPACE code overpredicts

the bypass fraction irrespective of the

nodalization finesse. The over- prediction at low

steam flow may be attributed to the difficulty

to accurately represent the flow regime in the

vicinity of the broken cold leg.

The Application of Knowledge

Management and TRIZ for solving

the Safe Shutdown Capability in Case of

Fire Alarms in Nuclear Power Plants

Chia-Nan Wang, Hsin-Po Chen,

Ming-Hsien Hsueh and Fong-Li Chin | Page 95

The Fukushima nuclear disaster in 2011 has raised

widespread concern over the safety of nuclear

power plants. This study employed knowledge

management in conjunction with the Teoriya

Resheniya Izobreatatelskih Zadatch (TRIZ) method

in the formulation of a database to facilitate the

evaluation of post-fire safe shutdown capability

with the aim of safeguarding nuclear facilities in the

event of fire. The proposed approach is meant to

bring facilities in line with US Nuclear Regulatory

Commission (NRC) standards. When implemented

in a case study of an Asian nuclear power plant, our

method proved highly effective in the detection of

22 cables that fell short of regulatory requirements,

thereby reducing 850,000 paths to 0. This study

could serve as reference for industry and academia

in the development of systematic approaches to the

upgrading of nuclear power plants.

Corrosion Processes of Alloyed Steels

in Salt Solutions

Bernhard Kienzler | Page 104

A summary is given of the corrosion experiments

with alloyed Cr-Ni steels in salt solutions performed

at Research Centre Karlsruhe (today KIT), Institute

for Nuclear Waste Disposal (INE) in the period

between 1980 and 2004. Alloyed steels show

significantly lower general corrosion in comparison

to carbon steels. However, especially in salt brines

the protective Cr oxide layers on the surfaces of

these steels are disturbed and localized corrosion

takes place. Data on general corrosion rates, and

findings of pitting, crevice and stress corrosion

cracking are presented.

Design and Development of a Radioecological

Domestic User Friendly Code for

Calculation of Radiation Doses and Concentration

due to Airborn Radionuclides

Release During the Accidental and Normal

Operation in Nuclear Installations

A. Haghighi Shad, D. Masti,

M. Athari Allaf, K. Sepanloo,

S.A.H. Feghhi and R. Khodadadi | Page 111

A domestic user friendly dynamic radiological dose

and model has been developed to estimate radiation

doses and stochastic risks due to atmospheric and

liquid discharges of radionuclides in the case of a

nuclear reactor accident and normal operation. In

addition to individual doses from different pathways

for different age groups, collective doses and

stochastic risks can be calculated by the developed

domestic user friendly KIANA Advance Computational

Computer Code and model. The current Code

can be coupled to any long-range atmospheric

dispersion/short term model which can calculate

radionuclide concentrations in air and on the

ground and in the water surfaces predetermined

time intervals or measurement data.

Event Report: Future Management –

Key Solutions for Nuclear Facilities

Matthias Rey | Page 121

Future management requires careful planning and

knowledge of what options are available, how far

optimizations make sense and which measures and

process changes have already proven themselves

elsewhere. The 2017 advanced course of the Swiss

Nuclear Forum took up this topic. On the first day

of the course, the focus was on solutions for

optimizing system operation and maintenance. The

second day focused on the employees in their

changing environment. As a novelty this year, the

topics of the morning input presentations were

discussed in depth in workshops on both afternoons.

Playing Politics with Nuclear is all Part

of the Game

John Shepherd | Page 134

If a week is a long time in politics – a statement

attributed to former British prime minister Harold

Wilson – then what about a month, or several

months – a period relevant for the use of nuclear

power? The nuclear industry has long accepted that

it can be used as a political football, to be kicked into

goal or off the pitch completely depending on the

situation at hand. Our industry therefore has power

in the political sense too, but with power comes

responsibility – nuclear leaders know that only too

well and now is as good as time as ever to lead by

example.

Abstracts | English

More magazines by this user