French Nuclear Reactors Reaching 40 Years

Transcription

1 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 st INRAG Conference on Nuclear RIsks Universität für Bodenkultur Vienna 17 April 2015 WISE-Paris 1

2 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 2

3 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 3

4 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 MWe - 4 units / 1 standard MWe (plus EPR under construction) A generic approach to life extension Therefore a generic risk for the nuclear strategy 4

5 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 5

6 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 WISE-Paris NURIS 2015 BOKU, Vienna 17 April

7 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

8 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 8

9 Scenarios Contrasted directions S1 S2 S3 Deteriorated safety Maintained safety Reinforced safety Reference requirements Limited evolution of existing requirements Strong evolution of existing requirements New set of requirements Conformity 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 Délais de réalisation Ongoing implementation through normal reexams Anticipation, proactive implementation, Implementation conditional to extension 9

10 Scenarios 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 A B C D E F G H I Technical options Reinforcement categories Protection against hazards cold source, electric feed, flooding, seism, fire Diffuse robustness hydraulic and electric equipments, structures Prevention of accident / reactor building vessel, primary circuit, steam generators Mitigation of accident / reactor building hydrogen risk, heat sink Containment / reactor building filters, containment wall, core-catcher Prevention of accident / fuel building additional storage, pool robustness, cooling Mitigation and containment / fuel building risque hydrogène, renforcement enceinte Ultimate means hard core for cold source, diesel generator Control and crisis management I&C, control room, crisis management building 10

11 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 11

12 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 12

13 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 13

14 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 14

15 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 15

16 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 ASN final generic decision in principle expected around 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) 16

17 Thank you for your attention and ready to answer your questions More information : WISE-Paris Yves Marignac, Director yves.marignac@wise-paris.org Tel : WISE-Paris NURIS 2015 BOKU, Vienna 17 April