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French Nuclear Reactors Reaching 40 Years
Decision process, reinforcement options and related costs
of a life extension of EDF nuclear reactors beyond their designed lifetime
Based on a report commissioned by Greenpeace France
Yves Marignac
Director of WISE-Paris
NURIS 2015
1st INRAG Conference on Nuclear RIsks
Universität für Bodenkultur
Vienna
17 April 2015
WISE-Paris
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Contents
“We all desire to reach an old age, but we all refuse that we’ve actually succeeded”
Francisco de Quevedo,
Politica de Dios y Gobierno de Cristo, 1619
Introduction
Objective of the study
Methodology
Situation
Technical/regulatory status of French plants
Safety, ageing and post-Fukushima issues
Concerns
Safety requirements applicable to PLEX
Decision and process and schedule
Scenarios
Contrasted technical scenarios
Related cost estimates
Conclusion
Lessons and recommendations
WISE-Paris
NURIS 2015 – BOKU, Vienna – 17 April 2015
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Introduction
Objective and method
Pressing political context
• 40 years of operation of French reactors approaching
• Since 2008, EDF has decided on a global strategy of life extension
French policy makers are convinced this is the best economic option
• However, operating costs already rise (Court of Account, 2012)
Moreover, life extensions are not granted (Nuclear Safety Authority, 2013)
• Meanwhile, France is now committing to reduce nuclear share
from above 75% of generation now down to 50% by 2025
Main objective
• Clarify the safety issues and discuss the options
• Raise public awareness about the risks and costs at stake
• Provide informed basis for decision making
by building contrasted reinforcement scenarios and estimate their costs
WISE-Paris
NURIS 2015 – BOKU, Vienna – 17 April 2015
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Situation
French nuclear fleet
An issue at national level
• 58 reactors on 19 sites
• A single operator – EDF
(>85% state-owned)
• A much standardized fleet
(all PWRs, 6 standards) :
- 34 units / 3 standards 900 MWe
- 20 units / 2 standards 1.300 MWe
- 4 units / 1 standard 1.450 MWe
(plus EPR under construction)
• A generic approach
to life extension
• Therefore a generic risk
for the nuclear strategy
WISE-Paris
NURIS 2015 – BOKU, Vienna – 17 April 2015
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Situation
Technical and regulatory age
The age of the French nuclear fleet
• 30 years of operation on average
(as of 31/12/2014, since first generation)
• A huge “cliff” effect (80% of reactors in 10 years)
• A decenial reactor per reactor
safety reassessement
with significant gap in the actual implementation
• A growing shift between the technical
and regulatory ages
- 27 reactors over 30 years of operation
- only 5 have completed 3rd reassessment and
obtained the authorization up to 40 years
- these 5 had 34 years operation on average
• No clear definition of a “40 years” limit
- neither calendary
- nor technical
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NURIS 2015 – BOKU, Vienna – 17 April 2015
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Concerns
Safety issues
ASN decision : come as close as possible of Generation III safety requirements (EPR)
A triple problematic
• Need to compensate ageing by reinforcements
• Introduction of new safety requirements after Fukushima-Daiichi
• Managing a growing uncertainty between theoretical and real status
years
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NURIS 2015 – BOKU, Vienna – 17 April 2015
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Concerns
Safety issues
Safety issues
• Intractable limits of the initial design
- for 30 to 40 years of operation at most (big / not replacable components)
- severe accidents discarded (before Three Mile Island and Tchernobyl)
• Unavoidable problems of ageing
- concerning big and especially not replacable components (vessel…)
- concerning diffuse equipement (e.g. pipings, electric wires…)
• Major failures of “in-depth defense” approach as demonstrated
by the return of experience after Fukushima
- design against external events
- reassessement of the risk of major accident on reactors
- evidence of the risk of severe accident arising from spent fuel storage
• Implementation of “stress tests” conclusions still a long process
=> Open questions regarding the final safety requirements,
the technical options and the feasibility of their implementation
WISE-Paris
NURIS 2015 – BOKU, Vienna – 17 April 2015
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Concerns
Decision process
Essential principes of access to information and participation
insuffisciently met in current processes
Processus
de décision
applicable
(VD3 + ECS)
• A technical process
leading to a technical
decision (between operator,
TSO and regulator)
• No formal process
of public participation
on generic requirements
or individual decisions
by reactor
• No or few formalisation
of opposable requirements
=> Need for a formal & serious
public participation process
WISE-Paris
NURIS 2015 – BOKU, Vienna – 17 April 2015
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Scenarios
Contrasted directions
S1
S2
S3
Deteriorated
safety
Maintained
safety
Reinforced
safety
Limited evolution
of existing requirements
Strong evolution
of existing requirements
New set
of requirements
Priority to reactive
maintenance
Mixed approach
Priority to preventive
maintenance
Technical
options
Consumption of margins,
minimal reinforcements
Targeted action,
ultimate “hard core”
Design upgrade,
strong reinforcements
Decision
process
Pursuing with
existing procedures
Reinforced participation
in existing procedures
First-license like
public process
Ongoing implementation
through normal reexams
Anticipation, proactive
implementation,
Implementation
conditional to extension
Reference
requirements
Conformity
Délais
de réalisation
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NURIS 2015 – BOKU, Vienna – 17 April 2015
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Scenarios
Technical options
Reinforcement categories
Systematic approach
• Based on the analysis of stakes
and the positions taken by ASN
• Based on the prevention and
mitigation of serious / major
accidents:
- in the reactor building
- in the spent fuel building
• A detail of 36 items
grouped in 9 categories
• Each item declined through
different solutions in each scenario
in the realm of technical realism
but not preempting their feasibility
cold source, electric feed, flooding, seism, fire…
B
hydraulic and electric equipments, structures…
Diffuse robustness
C
Prevention of accident / reactor building
D
Mitigation of accident / reactor building
E
Containment / reactor building
F
Prevention of accident / fuel building
G
Mitigation and containment / fuel building
H
Ultimate means
I
WISE-Paris
Protection against hazards
A
vessel, primary circuit, steam generators…
hydrogen risk, heat sink…
filters, containment wall, core-catcher…
additional storage, pool robustness, cooling…
risque hydrogène, renforcement enceinte…
“hard core” for cold source, diesel generator…
Control and crisis management
I&C, control room, crisis management building
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Scenarios
Cost estimates
Projections for one reactor
• Cautious assumptions,
medium values with uncertainty range
• High discrepancy of costs depending
on the level of safety
(also subject to local variations)
Scenario S1 : ~ 350 M€ ± 150 M€
Scenario S2 : ~ 1350 M€ ± 600 M€
Scenario S3 : ~ 4350 M€ ± 1850 M€
• A high profitability stake
for the operator
• Uncertainty bars:
- no crossing of scenarios
- no change in costs ratios
between scenarios
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NURIS 2015 – BOKU, Vienna – 17 April 2015
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Scenarios
Cost estimates
Sensitivity analysis
• S1 : 5 items = 50 % of uncertainty (ultimate equipments)
S3 : 4 items = 50 % of uncertainty (“bunkerisation”)
S2 more balanced
• 1/4 of items make 2/3 of the global cost difference
between scenarios
• Most of these items are crucial to the reinforcement
of reactors safety (especially “bunkerisation”)
• These big items are also the most uncertain
(ex. between €500 M€ and 1,5 Md€ for spent fuel building)
• Conversely, cost estimates are robust
to uncertainty on more diffuse costs
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NURIS 2015 – BOKU, Vienna – 17 April 2015
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Conclusion
Findings and recommendations
• The 40 years deadline (although not clearly defined) comes close,
and the “cliff” effect imposes to take urgent and massive action
• The natural trend is to go for life extensions by “fait accompli”
due to lack of action, in a poor political and regulatory framework
• EDF plans to invest in life extension without sufficient visibility
creates a strong risk of regulatory, industrial and financial entrapment
• The issue of the safety requirements applying to extension beyond 40 years
and the technical options remain uncertain, therefore also the costs
• The global life extension programme aimed for by EDF is most challenging:
- technical feasibility is not guaranteed,
- industrial capacity to manage heavy work on such a large scale
and in such a short time is doubtful,
- financial capacity of EDF is not there
• In any case, it seems that to maintain the French nuclear installed capacity
at its current level is already out of reach of EDF
WISE-Paris
NURIS 2015 – BOKU, Vienna – 17 April 2015
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Follow-up
Cost implications
Court of Accounts: EDF plan of €55 billion is unrealistic, corrected to €110 billion
First calculation of the impact on generating costs
Investments bring the generating cost up to €50 to €110/MWh
Current guaranteed gross tarif for generating cost is €42/MWh, ~above baseload market
€/kW
Source: Global Chance
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NURIS 2015 – BOKU, Vienna – 17 April 2015
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Follow-up
Public debate
National Assembly, Inquiry Commission on nuclear costs, 2014 report :
• “the report by WISE is one element of the debate on reactors’ life extension”
• ASN : “the frame of analysis and the questions raised by the WISE report [are] the right ones
and widely correspond to those of ASN”
• EDF / Nuclear Division Head : “also confirmed the relevance of this work and the accuracy
of a number of its assessments, although there is a big gap on 4 to 5 items which makes most
of the difference between EDF and WISE”
ASN in a Parliament Hearing, 15 April 2015 :
Post-Fukushima upgrade of a reactor will cost hundreds of million euros,
and is not the major part of the costs to pursue operation”
National Bill on Energy Transition (almost passed)
• No public consultation at national level on life extension programme
• No definition of the starting point to count 40 years, no specific regulation
• But life extension beyond 40 years of each reactor subject to a public inquiry, with EIA
However, EPR crisis is likely to increase pressure for low-cost large extension
WISE-Paris
NURIS 2015 – BOKU, Vienna – 17 April 2015
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Follow-up
Nuclear expertise
Two major areas for engagement of independent nuclear expertise
Monitoring the French safety assessment and decisions
• Long and complex safety assessment process is in its first phase
- ASN decision on generic terms of reference of 40 yers reassessment expected end of 2015
- ASN final generic decision in principle expected around 2018
- then reactor by reactor examination
• ASN publicly keen on maintaining high requirements:
French decisions will set a strong precedent
Stirring reflexion on the need for shutdown criteria
• Dominant representation: safety of reactors increases with time
conformity is monitored, reinforcements are introduced
• Realistic representation: safety of reactors is increasingly at risk
conception and fabrication margins are consumed, undetected non conformity increases
• Need to define before it is too late what the final limit should be, e.g.
- deterministic (thresholds corresponding to the ageing of key components)
- probabilistic (threshold regarding the relative increase of probability of some scenarios)
- regulatory (discovery of non conformity, failure to implement due repairs in time)
WISE-Paris
NURIS 2015 – BOKU, Vienna – 17 April 2015
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Thank you for your attention
and ready to answer your questions
More information :
WISE-Paris
Yves Marignac, Director
E-mail : yves.marignac@wise-paris.org
Tel : +33 6 07 71 02 41
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NURIS 2015 – BOKU, Vienna – 17 April 2015
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