ASN Report 2020

the reactor pressure vessel (see point 2.2) and its containment (see point 2.3), as well as obsolescence management, are essential for maintaining a satisfactory level of safety. After considering that the steps taken or planned by EDF, notably for identifying the various equipment degradation modes, implementing the corresponding countermeasures and integrating operating experience feedback, were on the whole satisfactory, in 2013 and then again in 2016, ASN – with the support of the IRSN – once more examined the ageing and obsolescence management approach and in March 2018 obtained the opinions of the GPR and GPESPN. ASN notes that EDF has taken account of the requests it made in 2013 and 2016. ASN considers that the steps taken or planned to ensure management of the ageing and obsolescence of the structures, systems and components of the 900 MWe reactors and thus contribute to maintaining their compliance beyond their fourth periodic safety review, supplemented by the undertakings made following the examination, are satisfactory. The programmes for equipment qualification for accident conditions are pertinent and enable this qualification to be extended beyond the fourth ten-yearly outage. Actions are still in progress to cover all the equipment concerned. The envisaged exceptional maintenance operations (replacements, repairs or renovations scheduled during or after the fourth ten- yearly outages) are consistent with the ageing assessments. The improvements identified for dealing with obsolescence are such as to guarantee satisfactory and lasting management of obsolescence. The programme of additional investigations defined by EDF and the planned procedures for processing the results are deemed to be on the whole satisfactory. ASN however identified weaknesses in the processing of operating experience feedback, advance planning of the decisions to be taken, the time taken to process certain generic ageing assessments and the assimilation by the NPPs of the demonstration of the suitability for continued operation. Finally, ASN considers that, without delaying their decom­ missioning, the final shutdown of the Fessenheim NPP reactors should be used as an opportunity to check the absence of any unexpected degradation or ageing phenomena, in particular on those parts of the installation that are hard to access. Moreover, the first Topical Peer Review, required by Council Directive 2014/87/Euratom of 8 July 2014, amending Directive 2009/71/Euratom establishing a community framework for the nuclear safety of nuclear installations, on the subject of ageing management, confirmed that the ageing management approach adopted for EDF’s nuclear reactors is appropriate. The national action plan drawn up to address the conclusions of this review was implemented in 2020, notably with regard to incorporation of the specific aspects of the sites in their local ageing management programme and the inspections on buried piping. In early 2021, ASN expects EDF to transmit information regarding the ageing management programme during the lengthy construction phases of new facilities and prolonged reactor outage periods. 2.11  Flamanville EPR The EPR is a PWR using a design that has evolved from that of the reactors currently in operation in France. It meets the following reinforced safety objectives: reduction in the number of significant events, limitation of discharges, reduced volume and activity of waste, reduced individual and collective doses received by the workers (in normal operation and incident situations), reduced overall frequency of core melt, taking account of all types of failures and hazards and reduced radiological consequences of any accidents. After a period of a decade during which no nuclear reactors were built in France, in May 2006 EDF submitted a creation authorisation application with the Ministers responsible for nuclear safety and for radiation protection, for an EPR type reactor with a power of 1,650 MWe on the Flamanville site, which was already home to two 1,300MWe reactors. The Government authorised its creation through Decree 2007- 534 of 10 April 2007, after a favourable opinion issued by ASN following the examination process. This Decree was modified in 2017 and in 2020, to extend the time allowed for commissioning of the reactor. After the issue of this Creation Authorisation Decree and the building permit, construction of the Flamanville EPR reactor began in September 2007. The first concrete was poured for the nuclear island buildings in December 2007. EDF aims to load fuel and start up the reactor at the end of 2022. This takes account of the time needed on the one hand to repair certain welds on the MSS and, on the other, to allow the end of the erection and testing operations. 2.11.1 Examination of the authorisation applications Examination of the commissioning authorisation application In March 2015, EDF sent ASN its commissioning authorisation application for the installation, including the safety analysis report, the general operating rules, a study of the facility’s waste management, the PUI, the decommissioning plan and an update of the facility’s impact assessment. Following a preliminary examination, ASN considered that all the documents required by the regulations were officially present, but it decided that additional justifications were needed if ASN was to be able to reach a final decision on the commissioning authorisation application. ASN began the technical examination of the subjects for which most of the information was available, although it did submit some requests on certain points. In June 2017, ASN received updated versions of the commission­ ing authorisation application files. Some elements still need to be provided before ASN is able to issue a position statement on the commissioning authorisation application file. In 2018, ASN more particularly issued requests for additional information regarding the general operating rules. ASN also obtained the opinion of the GPR on 4 and 5 July 2018 concerning the safety analysis report for the Flamanville EPR reactor. This meeting was devoted in particular to the action taken following the previous GPR sessions devoted to this reactor since 2015. The Advisory Committee considers that the reactor’s safety case is on the whole satisfactory and points out that some additional information is still required concerning how the fire risk is addressed and the behaviour of the fuel rods which have experienced a boiling crisis. The GPR also considers that the design and dimensioning of the back-up systems and auxiliary safety systems are on the whole satisfactory and observes that additional information is still required concerning the breaks liable to affect the fuel storage pool cooling system. In 2019, ASN submitted requests for supplements to the safety case that are needed for a final decision to be reached on the commissioning authorisation application. Finally, in 2020, ASN specified the required additions to the commissioning authorisation application so that it includes the conclusions of the technical examinations conducted. ASN Report on the state of nuclear safety and radiation protection in France in 2020 315 10 – THE EDF NUCLEAR POWER PLANTS 10