Safety Benchmark of Borssele Nuclear Power Plant
|Borssele Benchmark Commission, P.Nabuurs, J.Lyons, R.Stück, B.Tomic, A.M.Versteegh
|1.01.8.20/75 (BORSSELE - ALGEMEEN)
|Available at government website, with Dutch summary, here
Uit de publicatie:
Safety Benchmark of Borssele Nuclear Power Plant Second report of the Borssele Benchmark Committee – 2018 Summary and Conclusions The task of the Borssele Benchmark Committee To establish an expert opinion on the safety is to determine whether the Elektriciteits level of KCB, as compared with the other 236 Produktiemaatschappij Zuid-Nederland (EPZ) water-cooled and water-moderated power ensures that ”Borssele nuclear power plant reactors in operation in the EU, USA and Canada, (Kerncentrale Borssele – KCB) continues to be the Committee had to develop its own methodo- among the twenty-five percent safest water- logy. There are no internationally harmonised cooled and water-moderated power reactors evaluations available for all safety aspects of a in the European Union, the United States of nuclear power reactor that expresses the safety America and Canada. As far as possible, safety in one well-defined number. Requirements for shall be assessed on the basis of quantified nuclear safety are established in most countries performance indicators. If quantitative in line with international safety standards of comparison is not possible for the design, the International Atomic Energy Agency (IAEA) operation, maintenance, ageing and safety and (within the EU) with the guides set up by management, the comparison shall be made the Western European Nuclear Regulators on the basis of a qualitative assessment by Association (WENRA) and the European Nuclear the Committee.” Safety Regulators Group (ENSREG). However, the responsibility lies with the national regula- This condition is part of an agreement not to tory authorities and despite the efforts of the close the plant in 2013 – as was politically international organisations to harmonize these intended – but to allow it, in principle, to requirements, national differences remain, and continue operation until 31 December 2033, the importance attached to various safety if safety requirements are met as stated in aspects is not necessarily uniform. regulations and license. In principle, advanced Probabilistic Safety This agreement was formalised in a covenant, Analysis (PSA) would make it possible to combine which also included the installation of the all relevant safety aspects of design and opera- Borssele Benchmark Committee to evaluate tions into one model. However, PSA methodo- whether KCB meets this condition. logies have not been standardized, and PSAs have not been conducted for all nuclear power This document represents the second report of plants. For those plants that do have PSAs, not the Committee. all of them are available to the Committee. To develop PSAs would require an enormous effort Since the publication of the first Committee and would be hindered by the unavailability of report, some reactors have been permanently standardised reactor specific information and shut down. Therefore, the list of reactors was data for all the 237 peer reactors. revised to include only the reactors still in operation by 31 December 2016 (the cut-off Furthermore, opinions about what is important date set by the Committee for its assessment). for nuclear safety evolve due to operating The final list of reactors involved in the bench- experience, including root cause analyses of mark contains a total of 237 reactors. incidents. Ranking reactor safety is, therefore, a compli- Secondly, the wider use of the Safety Aspects cated, if not impossible task with a time- of Long Term Operation (SALTO) review mission dependent outcome. Nevertheless, the made it possible to conduct the evaluation of Committee is convinced that it developed a ageing using the recently refined and interna- meaningful methodology based on all available tionally consistent methodology developed information in combination with expert assess- by the IAEA for SALTO review. The use of the ment, that could be used to compare the safety findings in SALTO reports is now the basis of of KCB with the other reactors the Committee the ageing benchmark, in a way comparable to had to assess. Operational safety evaluations that uses the IAEA OSART findings (chapter 5). For the second report, the Committee retained the overall structure of the methodology Thirdly, the increased worldwide consciousness previously developed, and improved it to reflect about the importance of safety culture is recent developments. In particular, three recent reflected in a more consistent and standardized developments led to refinements and additions: approach (chapter 8). Firstly, post-Fukushima studies and their follow Schematically the Committee opted for the up brought new insights about design safety, approach as shown in Figure 1-1 (see page 8). leading to refinement and extension of the design benchmark methodology (chapter 4) and a separate evaluation of siting (chapter 6).