ASN Report 2022

A summer marked by an exceptional heatwave and drought which had no impact on nuclear safety The summer of 2022 was marked by an exceptional heatwave and drought which, for the first time since 2003, obliged ASN to issue resolutions waiving thermal discharge requirements and keeping five reactors in operation. This situation had no consequences for nuclear safety. Environmental monitoring was specifically strengthened so that any deterioration of the environment could be rapidly detected. The initial results of this monitoring, produced at the end of 2022, revealed no impact on the environment downstream of the facilities. According to the Intergovernmental Panel on Climate Change (IPCC), the frequency of this summer’s extreme episodes could double or even triple by the year 2050. The management of their consequences will require consolidation of scientific knowledge on the environmental consequences of water intake and discharge, along with forward planning concerning the long-term global issues. A backdrop of war in Ukraine that is undermining safety responsibilities With regard to the situation of the nuclear facilities in Ukraine, ASN together with its European counterparts conducted a joint assessment of the radiological consequences of a possible accident scenario. The work to reinforce nuclear facilities in the wake of the accident on the Fukushima Daiichi Nuclear Power Plant – NPP (Japan) led to an increase in the robustness of the Zaporizhzhia NPP (Ukraine), notably regarding the loss of off-site power risk. However, nuclear facilities are not designed to withstand acts of war. ASN considers that it is fundamental that the licensee of a facility can in all circumstances exercise its prime responsibility for safety, notably by maintaining control of the decision-making chain, and that the operators can act without being subjected to physical and psychological pressure, whether for day-to-day management of safety or in the event of a possible accident situation. ASN also recalls that Ukraine’s State Nuclear Regulatory Inspectorate of Ukraine (SNRIU), which is legally responsible for the oversight of nuclear safety, should be able to carry out its duties without hindrance. EPR commissioning which remains conditional on the final milestones to be reached In 2022, EDF devoted major efforts on the Flamanville site to carry out the final activities required prior to commissioning, to requalify the facility following the modifications and repairs made. ASN however underlines that significant work is still to be done ahead of commissioning, to carry out the final hot testing campaign on the site and also to complete the conformity justifications of the nuclear pressure equipment. At the request of ASN, EDF conducted in-depth analyses to identify the causes of the anomalies affecting the fuel and the core, which had been observed in the first EPR reactors abroad, along with their consequences for safety. EDF in particular learned the lessons regarding the design of the fuel assemblies which will be incorporated as from the first loading into the reactor, to prevent the risk of loss of fuel integrity. EDF is also examining the design of a system to prevent the hydraulic phenomena observed in the first reactors. ASN recalls that analyses are still needed to substantiate the design of certain safety-related equipment, notably the reliability of the pressuriser valves and the performance of the filters for the water reinjected from the bottom of the reactor building in an accident situation. Innovative small reactor projects which raise unprecedented safety issues In a context where the aim is decarbonised energy production, there is considerable interest worldwide in Small Modular Reactors (SMR), more particularly in those countries with no NPPs. This interest should not however overshadow the nuclear safety and security issues raised by these reactors. They should be accorded just as much importance as the decarbonised electricity generation concerns. The deployment of these small reactors for various uses could in particular lead to them being sited in industrial or built-up areas, raising specific questions such as the licensee’s capacity to control the risk of malicious acts or the proliferation of nuclear materials. Moreover, the deployment of these small reactors will not only require an industrial chain for their construction, but also the development and implementation of specific management for spent fuel and waste which do not yet exist. … 4 ABSTRACTS – ASN Report on the state of nuclear safety and radiation protection in France in 2022 Editorial by the Commission