ASN Report 2018

reactors facilitates their decommissioning compared with other reactor technologies. The decommissioning of this type of installation presents no major technical challenges and its feasibility is guaranteed. Whatever the service life of the reactors in operations, EDF will be confronted with the simultaneous decommissioning of several PWRs in the coming years and will therefore have to organise itself to industrialise the decommissioning process in order to meet the requirement to decommission each installation in the shortest time possible. 2.1.2  –  Nuclear power reactors other than PWRs The nuclear power reactors that are not PWRs are all industrial prototypes. These comprise the first-generation Gas-Cooled Reactors, the EL4-D heavy water reactor on the Brennilis site, and the sodium-cooled fast breeder reactors Phénix and Superphénix. These reactors have been shut down for several decades, which has led to loss of knowledge of the installation and its operation and loss of the skills associated with these reactors. The decommissioning of these reactors is characterized by the lack of prior national or international experience. As with the PWRs, decommissioning begins with the removal of the nuclear fuel, which removes 99% of the radioactivity present in the installation. As the thermal powers of these reactors are relatively high (all greater than 250 MWth), their decommissioning necessitates the cutting away and removal of the activated parts of the reactor core. Remotely-operated means are therefore used in these highly irradiating zones. In view of their unique nature, specific and complex operations have to be devised and carried out to decommission them. The GCRs have the particularity of being extremely massive and large-sized reactors, necessitating innovative cutting and access techniques under highly irradiating conditions. The decommissioning of these reactors will oblige EDF to manage significant volumes of waste. The final disposal route for some of this waste is in the process of being determined, such as the graphite bricks, for which LLW-LL disposal is envisaged. Decommissioning of the EL4-D reactor (prototype heavy water reactor) has been hindered, firstly due to the lack of prior experience in the decommissioning techniques to use, and secondly due to unforeseen setbacks in the commissioning of the storage facility dedicated to the most highly active waste (Iceda, see introductory section and chapter 14). The decommissioning of the sodium-cooled reactors (Phénix and Superphénix) has met with no major technological obstacles. The specific challenges lie chiefly in the control of the fire risk due to the presence of sodium and the safety of these treatment processes. Installations definitively shut down or in the process of decommissioning as at 31 December 2018 La Hague (Areva NC) BNI 33 - Spent fuel reprocessing plant (UP2) BNI 38 - STE2 BNI 47 - ÉLAN IIB La Hague BNI 80 - HAO Saclay (CEA) BNI 18 - Ulysse BNI 40 - Osiris BNI 49 - High-Activity Laboratory (LHA) Brennilis (EDF) BNI 162 - EL4-D Chinon (EDF) BNI 94 - Irradiated Materials Facility (AMI) BNI 133 - Chinon A1D BNI 153 - Chinon A2D BNI 161 - Chinon A3D Saint-Laurent-des-Eaux (EDF) BNI 46 - Saint-Laurent-des-Eaux A1 and A2 Fontenay-aux-Roses (CEA) BNI 165 - Process BNI 166 - Support Tricastin (Areva NC) BNI 105 - Comurhex Tricastin (Eurodif Production) BNI 93 - Eurodif Chooz (EDF) BNI 163 - Chooz A Bugey (EDF) BNI 45 - Bugey 1 Creys-Malville (EDF) BNI 91 - Superphénix Veurey-Voroize (SICN, subsidiary of Areva) BNI 65 and 90 - SICN Grenoble (CEA) BNI 36 - STED BNI 79 - Decay interim storage facility *The CEA shut down the Masurca reactor in December 2018. Marcoule (CEA) BNI 71 - Phénix Cadarache (CEA) BNI 25 - Rapsodie BNI 32 - ATPu BNI 37B - Effluent Treatment Station (STE) BNI 39 - Masurca* BNI 42 - ÉOLE BNI 52 - ATUE BNI 53 - MCMF BNI 54 - LPC BNI 56 - Radioactive waste interim storage area BNI 92 - Phébus BNI 95 - Minerve 340  ASN report on the state of nuclear safety and radiation protection in France in 2018 13 – DECOMMISSIONING OF BASIC NUCLEAR INSTALLATIONS