Technical Meeting on Novel Design and Safety Principles of Nuclear Power Plants
IAEA Headquarters, Vienna, Austria 3–6 October 2016
Actions taken in WANO-Moscow
Centre to incorporate lessons learned from
Fukushima Accident
Sergey Vybornov Adviser , peer review programme World Association of Nuclear Operators – Moscow Centre
2 Technical Meeting on Novel Design and Safety Principles of Nuclear Power Plants
Vienna, Austria. 3–6 October 2016
Contents
Actions taken among WANO members to prevent severe accidents and mitigate their consequences
Changes in WANO peer reviews with focus on design vulnerabilities of existing plants
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Vienna, Austria. 3–6 October 2016
What is WANO
Mission of the World Association of Nuclear Operators is to maximise the safety and reliability of nuclear power plants worldwide by working together to assess, benchmark and improve performance through mutual support, exchange of information, and emulation of best practices.
Four main programmes:
Operating experience exchange
Technical and professional development
Technical support and exchange of technical information
Peer reviews
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Vienna, Austria. 3–6 October 2016
Lessons learned from Fukushima
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Vienna, Austria. 3–6 October 2016
SEVERE ACCIDENT MANAGEMENT PROJECT
WANO Post-Fukushima Commission:
“The full focus of WANO since its formation has been accident prevention, and no procedures were in place to address nuclear response or mitigation”.
We have to shift from a focus on accident prevention to a focus on both prevention and mitigation.
Recommendation No.1 resulted in the launching of the SAM Project.
Overall responsibility for the SAM Project was delegated to the WANO Moscow Centre.
WANO SAM Project: Background
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Vienna, Austria. 3–6 October 2016
7 Technical Meeting on Novel Design and Safety Principles of Nuclear Power Plants
Vienna, Austria. 3–6 October 2016
SAM project
The purpose of the SAM Project was to:
expand the scope of WANO programmes to include severe accident management
establish a worldwide standard for performing station and corporate assessments in the area of severe accident management
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Vienna, Austria. 3–6 October 2016
SAM project
As a result SAM Performance Objectives and Criteria (SAM PO&Cs) were developed and were supposed to be used during station peer reviews to review readiness of nuclear plants to manage beyond-design-basis and severe accidents.
The SAM PO&Cs are a set of the following three performance objectives, with corresponding criteria:
SAM.1: SAM MANAGEMENT AND LEADERSHIP
SAM.2: SEVERE ACCIDENT MANAGEMENT PROGRAMME
SAM.3: SEVERE ACCIDENT RESPONSE
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Vienna, Austria. 3–6 October 2016
SAM project
Decision was made that all WANO member utilities/stations should carry out self-assessments.
Self-assessments have been conducted for WANO member stations worldwide (Final report issued on 30 August 2015 ).
Question: Are Severe Accident Management programs adequate:
to provide effective direction and coordination of mitigation strategies to prevent the escalation of a beyond-design-basis event into a severe accident,
to mitigate the consequences of a severe accident and achieve a long-term safe stable state if a severe accident has occurred.
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Vienna, Austria. 3–6 October 2016
Results of self-assessment
Overall results: members meet most standards and are prepared to manage severe accidents effectively. However:
Some – not adequately provided with equipment and facilities (mobile emergency equipment to ensure long-term heat removal from the core and from spent fuel, equipment for in-containment hydrogen suppression, alternative paths for water supply, seismic protection of systems, structures and components, etc.
Development of SAMGs and other documentation for severe accident response has not been completed.
Sufficient capability is not ensured to manage severe accidents, including multi-unit events, from protected emergency control centres both during the design-basis phases and during prolonged events.
Weaknesses in SAM training (simulator training, drills for SAM, handover of command and control during prolonged events, relief/rotation, communication, multiple-unit drills.
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Performanc
e Objective Category
Number of Stations
SAT AI UNSAT
SAM.1 SAM MANAGEMENT AND
LEADERSHIP 17 6 -
SAM.2 SEVERE ACCIDENT MANAGEMENT
PROGRAM 10 13 -
SAM.3 SEVERE ACCIDENT RESPONSE 19 4 -
SAM self-assessment
SAM Performance Objectives Implementation, WANO – MC
Technical Meeting on Novel Design and Safety Principles of Nuclear Power Plants Vienna, Austria. 3–6 October 2016
Source: WANO-MC Director presentation “WANO Post-Fukushima Severe Accident Management Project”
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Further steps
revise the SAM PO&Cs based on the self-assessment results and comments from the members
incorporate the revised SAM PO&Cs in the WANO PO&Cs
make arrangements to review SAM on peer reviews
proceed with adding SAM to the scope of WANO programmes and activities.
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Vienna, Austria. 3–6 October 2016
DESIGN INFORMED PEER REVIEWS
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Vienna, Austria. 3–6 October 2016
Design informed peer reviews
WANO’s mission is “to maximise the safety and reliability of nuclear power plants”; for achieving this mission, it is very important to have in mind that nuclear safety of a plant strongly depends on two fundamentals:
the “design phase” which results in the definition of the Design Basis and Beyond Design basis considerations of the plant,
the “operation phase” which corresponds to the day-by-day life of the plant.
The Design Project has been established by the 2011 with the mandate to provide recommendations to extend the scope of WANO activities to include some aspects of Design.
The Design Project “Design-Informed Peer Reviews” = More global appreciation of the nuclear safety of a plant
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Vienna, Austria. 3–6 October 2016
Objectives of the Design Informed Peer Reviews
To appreciate the nuclear safety performance of the plant taking into account the main characteristics of the design,
To ensure potential design vulnerabilities are known and managed by the plant,
To evaluate whether the Fundamental Safety Functions (control of reactivity, removal of heat from the reactor core and from the spent fuel, confinement of radioactive material), are challenged or not by the plant operation performance.
As a result:
More focused peer review teams
An analysis of the available data in terms of safety function performance
Design Information Survey (DIS)
P1 Generic
questions P3
Control of reactivity
P4 Confinement
P5 Heat
Removal
P6 Emergency
Power supply
P7 Monitoring
of plant parameters
P2 External Events
Unit: X Station name
Is this event considered as
Design Basis, Design
Extension Condition,
Beyond Design Basis or
not relevant for the station?
If the event is not taken into
account for your station,
explain why.
Specify the Design Basis
limit values and the
duration for the specific
event where appropriate
and give a reference (e.g.
maximum water (wave)
height / temperature;
frequency and acceleration;
liquid equivalent, etc.).
Provide the maximum
values for which it is
proven that the plant is
protected against, if
different from previous
question (e.g. maximum
water (wave) height /
temperature; duration;
frequency and acceleration;
liquid equivalent, etc.)
Has such an event
occurred which challenged
safety functions at your
station since erection? If
yes, provide the event code
and characteristic value
(e.g. Max. water height /
temperature; duration;
frequency and acceleration;
liquid equivalent; etc.
External Events
Did the Design Basis Limit
values change since the
plant was built? (Was the
event originally foreseen
for the station?)
Se
ism
ic
Earthquake
Ex
tre
me
Me
teo
rolo
gic
al / H
yd
rolo
gic
al
Co
nd
itio
ns
Extreme air temperature (high and low)
Extreme humidity / Drought
Lightning
Heavy Rain
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Probabilistic Safety Assessment Survey (PSAS)
Initiating events and operational modes.
Identifies the systems and components of higher importance
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Safety Function Examination (SaFE)
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A-B-C-X … - Excel spreadsheets: facts and conclusions grouped for
Safety functions
Technical Meeting on Novel Design and Safety Principles of Nuclear Power Plants Vienna, Austria. 3–6 October 2016
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Results for the peer review team
This information is then used in order to:
Determine areas that might warrant particular focus of the peer review team,
Highlight some priorities for the on-site Peer Review,
Evaluate the potential cumulating challenge to Fundamental Safety Functions.
DiPR were conducted for several technologies: BWR (different types), PWR (different types), PHWR, AGR, VVER
Target: in 2019 all 100% member stations will host design informed peer reviews
Feedback from the customers
Station A:
“Valuable feedback. The DiPR has identified aspects that need to be reconsidered before […] implementing any modifications, not necessarily design modification.”
Station B:
“The analysis shows that the DiPR analysis added value to the existing process by identifying gaps in safety function performance that were not otherwise identified by the peer review.”
Station C:
“Station has not got inputs and additional questions on design resulted from the peer review”.
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Technical Meeting on Novel Design and Safety Principles of Nuclear Power Plants Vienna, Austria. 3–6 October 2016 20
Conclusions
The methodology has proved to be robust and valuable:
New approach provides new insights e.g. aggregation of small gaps that can result in a cumulative challenge.
Independent review provides a new perspective e.g. margin assessments for unexpected conditions.
Results can be used to inform or validate decision making on e.g. capital projects, modifications, safety reviews…
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QUESTIONS???
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2016
WANO Moscow Centre
Tel: +7 495 376 15 87
Fax: +7 495 376 08 97
Web: www.wanomc.ru
E-mail: [email protected]
Sergey Vybornov
Tel: +7 495 221 02 74
E-mail: [email protected]
