ASN Report 2020

Nogent-sur-Seine nuclear power plant Operated by EDF and situated in the municipality of Nogent-sur-Seine in the Aube département , 70 km north- west of Troyes, the Nogent‑sur‑Seine NPP comprises two PWRs each of 1,300 MWe, commissioned in 1987 and 1988. Reactor 1 constitutes BNI 129 and reactor 2 BNI 130. ASN considers that the performance of the Nogent-sur Seine site in nuclear safety, and to a lesser extent in radiation protection, is below the general assessment of EDF. The environmental protection performance stands out positively with respect to the average for the EDF plants and is considered satisfactory. With regard to nuclear safety, ASN considers that the operating rigour is not of the expected standard. The significant number of system configuration errors and deviations from the reactor operating technical specif ications must be addressed in priority by the licensee. ASN nevertheless notes progress in the rigour of monitoring in the control room. Final shutdown of the Fessenheim site and preparation for decommissioning Pursuant to the final shutdown declaration sent to the Minister responsible for nuclear safety and to ASN on 27 September 2019, EDF proceeded with the final shutdown of the two reactors of the Fessenheim NPP in 2020, the first on 22 February and the second on 30 June. In June 2020, EDF published a new version of the Fessenheim NPP decommissioning plan in response to ASN’s requests for complements to the initial version of the plan received with the final shutdown declaration. In this new version EDF provides the justifications requested by ASN concerning the strategy applied in choosing the decommissioning preparation operations and the details concerning primary system decontamination and the spent fuel removal schedule. In November 2020, EDF sent the decommissioning file provided for in Article L. 593‑27 of the Environment Code to the Minister responsible for nuclear safety with a view to obtaining the Decommissioning Decree. If the Minister deems this file admissible, it will refer it to ASN for examination as from 2021. Alongside this decommissioning file, ASN will also examine the concluding report of the periodic safety review of the two Fessenheim reactors submitted by EDF in September 2020. ASN will thus assess the conditions of safety of the installation during the decommissioning preparation and short-term decommissioning phases. EDF plans a 5-year decommissioning preparation phase, which will span the period until the reactor Decommissioning Decree is obtained. Once this decree is obtained, it should take about twenty years for site decommissioning to reach the final state, with the aim of delicensing the Basic Nuclear Installation. The main decommissioning preparation operations envisaged by EDF consist in removing all the fuel present on the site and decontaminating the primary system of each of the two reactors. The aim of this operation is to minimise the risks associated with ionising radiation during decommissioning of the installation. In addition, areas for treating and packaging the waste resulting from the future decommissioning work must be set out in the premises. Consequently, following final shutdown the cores of the two reactors have been completely unloaded; the spent fuel has been stored in the site’s cooling pools pending transfer to the La Hague treatment facilities. About ten spent fuel removal transport operations were carried out in 2020. ASN resolution 2020-DC-0699 of 17 November 2020 requires EDF to complete the fuel removal operations by the end of 2023. EDF has also started decommissioning preparation work, notably concerning removal of the old steam generators which is planned during the decommissioning preparation phase, with the aim of freeing up and reusing the storage building for the decommissioned steam generators. EDF plans transferring the six old steam generators, currently stored on site, to its Cyclife plant in Sweden for melting down and recovery. As for the decommissioned steam generators, EDF plans recovering them in a centralised cutting and melting facility that EDF would like to set up in France. Although Article 6 of the resolution of 21 February 2020, taken jointly by the Minister responsible for nuclear safety and the ASN Chairman, opens up the prospect of a change in the regulatory framework applicable to the management of very low level waste (VLLW) (see chapter 14) in order to introduce a new possibility of targeted waivers allowing, after melting and decontamination, recovery on a case-by-case basis of very low level radioactive metal waste, the corresponding regulatory framework remains to be developed with respect to French law. ASN carried out an in-depth inspection at the EDF’s Department of Dismantling Projects and Waste (DP2D) and on the Fessenheim site in November 2019. During that inspection ASN identified shortcomings in the management of the Fessenheim decommissioning project, which at the time did not give EDF an overall picture of the project with all its interactions. In response to this, EDF set up a project dedicated to the decommissioning preparation phase, the aim of which is to guarantee that the initial decommissioning state is reached by 2025: this new organisation integrates all the EDF contributing entities in this project, starting with the site. Through this project EDF has also bolstered its organisation in order to establish and validate the structuring decisions for the decommissioning preparation phase and then for the decommissioning itself. ASN considers that the organisational changes proposed by EDF are on the whole satisfactory and will make sure that they are reflected operationally in the management of the future operations. See chapter 13 for further information on the decommissioning of the Pressurised Water Reactors (PWRs). 62 ASN Report on the state of nuclear safety and radiation protection in France in 2020 REGIONAL OVERVIEWOF NUCLEAR SAFETY AND RADIATION PROTECTION