experienced a boiling crisis. The GPR also considered that the design and dimensioning of the back-up systems and auxiliary safety systems are on the whole satisfactory and observed that additional information was still required concerning the breaks liable to affect the fuel storage pool cooling system. In 2019 and 2020, in the light of this opinion and the conclusions of its technical examinations, ASN submitted requests for supplements to the safety case that are needed for it to make a final decision on the commissioning authorisation application. In June 2021, EDF sent ASN a new commissioning authorisation application. This application replaces the initial application of March 2015 and contains a complete update of the file appended to the initial application, incorporating certain additions requested and the conclusions of the examinations conducted since 2015. Partial commissioning authorisation for arrival of the fuel On 8 October 2020, ASN authorised partial commissioning of the installation for arrival of the fuel on the site. This authorisation enabled EDF to receive fuel assemblies and store them in the fuel storage pool, for use in the first fuelling of the reactor. This partial commissioning is one of the steps prior to commissioning of the Flamanville EPR reactor, but in no way prejudges this commissioning, which is the subject of a separate examination. 3.2 Construction, start-up tests and preparation for operation ASN is faced with numerous challenges concerning oversight of the construction, start-up tests and preparation for operation of the Flamanville EPR reactor. These are: ∙ checking the quality of equipment manufacturing and installation construction, in order to be able to issue a position statement on the ability of the installation to meet the defined requirements; ∙ ensuring that the start-up tests programme is satisfactory, that the tests are correctly performed and that the required results are obtained; ∙ ensuring that the various stakeholders learn the lessons from the construction phase and the performance of the start-up tests, including the upstream phases (selection and monitoring of contractors, construction, procurement, etc.) which will enable the as-built installation to comply with the safety case for the duration of the project; ∙ ensuring that the licensee takes the necessary steps so that the teams in charge of operating the installation after commissioning are well-prepared. To do this, ASN has set binding requirements regarding the design, construction and start-up tests for the Flamanville EPR reactor and for operation of the existing two Flamanville 1 and 2 reactors close to the construction site. As this is a nuclear power reactor, ASN is also responsible for labour inspection on the construction site. Lastly, ASN ensures oversight of the manufacture of the NPE that will be part of the primary and secondary systems of the nuclear steam supply system. In 2022, EDF continued with work to complete the installation, to make modifications to certain equipment and to draw up the various documents needed for operation. EDF also continued to analyse and remedy deviations, notably those affecting the MSS welds as well as three main primary system nozzles. EDF implemented a programme of additional inspections as part of the quality review requested by ASN owing to significant shortcomings observed in the monitoring of its contractors. EDF also continued to conduct the reactor start-up test programme and initiated preparations for the equipment requalification phase, scheduled in 2023 in preparation for commissioning. 3.3 Assessment of design, construction, start-up tests and preparation for operation of the Flamanville EPR reactor The examinations in progress ASN considers that the design of the Flamanville EPR reactor should be able to achieve the ambitious safety objectives set for the third generation reactors. It should also lead to a significant reduction in the probability of core melt and radioactive releases in the event of an accident, by comparison with the second generation reactors. The EPR reactor design in particular includes systems for managing severe accidents and is able to withstand extreme external hazards. This design only required very minor changes to take account of the lessons learned from the accident at the Fukushima Daiichi NPP. In 2022, EDF continued with the examinations linked to the commissioning authorisation application. A number of important technical subjects are still being examined. This is in particular the case with the design of the primary system safety valves, I&C upgrades, the performance of the containment internal water tank filtration system, the RGEs that will be applicable as of commissioning and incorporation of the lessons learned from the commissioning of the first EPR reactors abroad, in particular the various anomalies found on the cores of the EPR reactors in Taishan (China), including the fuel clad perforations observed in 2021. THE AGEING OF NUCLEAR POWER PLANTS EQUIPMENT As in any industrial installation, the equipment in NPPs experiences ageing. This ageing is the result of physical phenomena (corrosion of metals, hardening of polymers, hardening of certain steels under the effect of irradiation or temperature, swelling of certain concretes, etc.) which can degrade their characteristics according to their age or their operating conditions. This degradation obliges the licensee to repair or replace the equipment or to limit the lifetime of non-replaceable equipment, such as the reactor pressure vessel (see point 2.2.4). The ageing management process implemented by EDF is based on three main points: anticipating the effects of ageing as of the design stage, monitoring the actual condition of the facility and repairing or replacing equipment degraded by the effects of ageing. Before being installed, equipment important for safety more particularly undergoes a qualification process to ensure its ability to perform its functions in conditions corresponding to the situations in which it will be needed, accident situations in particular. The management of equipment ageing, and of the risk of obsolescence – which refers to difficulties linked to guaranteeing the procurement of spares over time – are essential to maintaining a satisfactory level of safety. They also contribute to reactor conformity being maintained over time. The control of ageing is given particular attention by ASN during the fourth periodic safety reviews. The provisions adopted or planned by EDF are examined and inspected, to ensure that the risks associated with ageing and obsolescence are controlled satisfactorily. ASN Report on the state of nuclear safety and radiation protection in France in 2022 313 • 10 • The EDF Nuclear Power Plants 10 01 07 08 13 AP 04 06 12 14 03 09 05 11 02
RkJQdWJsaXNoZXIy NjQ0NzU=