Abstracts ASN Report 2021

New energy policy prospects which must address safety concerns at once Five of the six scenarios presented in the Réseau de transport d’électricité (RTE) report, produced at the request of the Government, on “Energies of the future”, aiming to achieve a decarbonised economy by 2050, are based on continued operation of the existing NPP fleet. At this stage, no conclusion on the continued operation of all these reactors beyond 50 years can be drawn from the information available to ASN during the generic examination of the fourth periodic safety review of the 900 MWe reactors, for which it issued its decision in February 2021. Due to the specific features of some reactors, it might not be possible, with the current methods, to demonstrate their ability to operate up to 60 years. Furthermore, over the longer term, one of the scenarios envisaged by RTE presents an electricity mix with a nuclear electricity share close to 50% in 2050. Consultation with industry revealed that the rate of construction of new nuclear reactors in order to achieve such a level would be hard to sustain, which led RTE also to base this scenario on the operation of some reactors beyond 60 years and the continued operation of the others until 60 years. This scenario, which is based on fundamental hypotheses of an operating lifetime which cannot at present be confirmed with regard to safety, also entails the risk of leading the electricity system into a dead-end, if the number of reactors able to operate until or indeed beyond 60 years proves to be insuff icient, and if this were only known belatedly. Moreover, the shutdown in a few years of a large number of reactors built during a short period of time in the 80s, could have “cliff-edge” consequences for electricity production capacity. ASN considers that the energy policy choices for the 2050 time-frame must be based on hypotheses that are robust and which can be justified in terms of safety. The choice of operating the current NPP fleet beyond 50 years and up to 60 years should include a step to justify this possibility, with sufficient margins for dealing with major or generic unexpected scenarios. In any case, if the hypothesis of continued operation of certain reactors beyond 60 years were to be an option, this should involve an examination, in advance, so that there is enough time –at least 15 years– to be able to adjust the energy policy choices in the light of its conclusions and avoid a situation in which the lack of forward planning leads to continued operation of the nuclear reactors based on a decision dictated purely by electricity needs or which is hazardous in terms of safety. The strong mobilisation of EDF must continue with a view to commissioning of the Flamanville EPR reactor The activities concerning weld repairs on the secondary systems (main steamlines and steam generator feedwater lines) of the Flamanville EPR, involved considerable efforts of EDF. Because of the deviations observed, about a hundred secondary system welds needed to be repaired. EDF produced specif ic mock‑ups and tests to qualify the repair processes. ASN carried out reinforced oversight of these worksites to ensure the quality of the new welds. According to the EDF schedule, repair of the welds on the secondary systems will continue until August 2022. Other work to correct deviations still has to be carried out ahead of commissioning, in particular concerning the primary system set-in nozzles. Moreover, ahead of the reactor commissioning authorisation, considerable work is still to be done on numerous topics with major safety implications, already identif ied several years ago. In particular, EDF must carry out numerous analyses, including tests, to justify the design of certain equipment, notably the reliability of the pressuriser valves and the performance of the f ilters for the water reinjected f rom the bottom of the reactor building in an accident situation. In some cases, this could require modif ications being made ahead of commissioning. EDF must also complete the required test programme for reactor commissioning and supplement it, in order to carry out requalif ication of the installation after the modif ications and repairs. ABSTRACTS – ASN Report on the state of nuclear safety and radiation protection in France in 2021 5 EDITORIAL BY THE COMMISSION