ASN Report 2020

FACILITIES UNDERGOING DECOMMISSIONING Superphénix reactor and fuel storage facility The Superphénix fast neutron reactor (BNI 91), a 1,200 MWe sodium-cooled industrial prototype is situated at Creys- Malville in the Isère département . It was def initively shut down in 1997. The reactor has been unloaded and the majority of the sodium has been neutralised in concrete. Superphénix is associated with another BNI, the APEC fuel storage facility (BNI 141). The APEC essentially comprises a pool containing the fuel unloaded from the reactor pres- sure vessel and the area for storing the soda concrete pack- ages resulting f rom neutralisation of the sodium f rom Superphénix. ASN considers that the safety of Superphénix decom­ missioning operations and of APEC operation is on the whole satisfactory. In 2018, ASN authorised commencement of the second Superphénix decommissioning phase, which consists in opening the reactor pressure vessel to dismantle its internal components, in dedicated facilities constructed in the reactor building, by direct or remote manipulation. The safety and radiation protection measures implemented by EDF for these operations are on the whole satisfactory. In 2020, a f ire broke out on a decommissioning worksite, leading EDF to activate its on-site emergency plan and prompting ASN to carry out a reactive inspection. Short­ comings were found at various levels in the execution of the procedures during this incident, particularly as regards communication with the stakeholders. Concerning the management of facility obsolescence, EDF reported difficulties in procuring certain items of equipment and significant delays in the replacement and repair of parts. ASN has asked the licensee to carry out a site-level diagnosis and to draw up an action plan on this subject. ASN will focus particular attention on the improvement in the site’s emergency organisation in 2021. Siloette, Siloé, LAMA reactors and effluents and solid waste treatment station – CEA Centre The CEA Grenoble centre (Isère département ) was inaugurated in January 1959. Activities associated with the development of nuclear reactors were carried out there before being gradually transferred to other CEA centres in the 1980’s. The Grenoble centre now carries out research and development in the areas of renewable energies, health and microtechnology. In 2002, the CEA Grenoble centre began a site delicensing process. The site accommodated six nuclear installations which have gradually stopped their activities and are now in the decommissioning phase with a view to delicensing. Delicensing of the Siloette reactor was declared in 2007, that of the Mélusine reactor in 2011, of the Siloé reactor in January 2015 and of the LAMA reactor in August 2017. The last BNIs on the site (BNI 36 and 79) are the Effluents and Solid Waste Treatment Station and the decay storage facility (STED). All the buildings have been dismantled, in accordance with their Decommissioning Decree. The technical discussions between ASN and the CEA concerning the radiological and chemical remediation of the soil of the STED continued in 2018. All the operations that can be technically achieved at a reasonably acceptable cost have been carried out. In view of the presence of residual chemical and radiological contamination, the licensee submitted a delicensing f ile along with a f ile for establishing active institutional controls in December 2019, which were deemed inadmissible by ASN in 2020 and for which the licensee must submit a new request. ASN Report on the state of nuclear safety and radiation protection in France in 2020 49 REGIONAL OVERVIEWOF NUCLEAR SAFETY AND RADIATION PROTECTION AUVERGNE-RHÔNE-ALPES