2.4 The back-end “nuclear fuel cycle” facilities The back-end facilities of the “nuclear fuel cycle” are the spent fuel storage pools, the spent fuel reprocessing plants and the facilities for storing waste from the treatment process. These facilities are operated by Orano and situated on the La Hague site. The first processing facility at La Hague was commissioned in 1966, initially for reprocessing the fuel from the first-generation GCRs. This facility, BNI 33, called “UP2-400” standing for “Production Unit No. 2-400 tonnes”, was definitively shut down on 1 January 2004 along with its support facilities, namely the effluent treatment station STE2 and the spent fuel reprocessing facility AT1 (BNI 38), the radioactive source fabrication facility ELAN IIB (BNI 47) and the “High Activity Oxide” facility (HAO), built for reprocessing the fuels from the “light water” reactors (BNI 80). Some of these facilities suffered accidents which led to contamination of the premises and their near environment, such as the 1981 fire in silo 130 which is part of BNI 38. Unlike the direct on-line packaging of the waste generated by the UP2-800 and UP3-A plants in operation, most of the waste generated by the first reprocessing plant was stored without treatment or packaging. Decommissioning is therefore carried out concomitantly with the legacy Waste Retrieval and Packaging (WRP) operations. About ten projects of this type are currently in progress in the old facilities (silos 115 and 130 in BNI 38 and the HAO silo in BNI 80). They will span several decades and are a prerequisite to the complete decommissioning of these facilities, whereas the decommissioning of the process parts of the plant is continuing with more conventional techniques. 2.5 The support facilities (storage and processing of radioactive effluents and waste) Many of these facilities, most of which were commissioned in the 1960’s and whose level of safety did not comply with current best practices, have been shut down. Old storage facilities were not initially designed to allow the removal of the waste, and in some cases they were seen as being the definitive waste disposal site. Examples include the SaintLaurent-des-Eaux silos (BNI 74), the pits, trenches and hangars of THE “DECAP” PROJECT By a resolution of 18 August 2022, ASN authorised implementation of the “DECAP” process (French acronym for “Removal of araldite-encapsulated fuels from Pégase”) in the CEA’s BNI 22 called “Pégase”. The “araldite-encapsulated” cans are sealed metal containers in which are placed spent fuel assemblies coated in a hardenable resin which sets them. This resin can react with the nuclear material by radiolysis, creating gases which can ultimately deform the cans. The DECAP process, currently being set up in the Pégase ➊ facility, will consist in repackaging in a shielded cell ➌, all the araldite-encapsulated cans stored at present in the facility’s pool, and transferring them to the Cascad ➋ facility for storage. This will involve several operations: ཛྷ piercing the wall of the outer can to evacuate any built-up gases, ཛྷ cutting away the outer can, ཛྷ extracting the inner can, ཛྷ piercing the wall of the inner can to evacuate any built-up gases, ཛྷ transferring the inner can to a container baptised “C3L” ➍. The “C3L” container, similar to those used on the Cascad facility, features a system for monitoring any build-up of gases. It is to be noted that further to the last periodic safety review of the Pégase facility, ASN required the repackaging operations to begin by the end of 2024 at the latest. The DECAP process will enable this requirement to be met. In this context, the CEA has set the target of finalising the repackaging of the Pégase pool cans by the end of 2030. ➊ Pégase ➍ “ C3L ” container ➌ Shielded cell ➋ Cascad facility ASN Report on the state of nuclear safety and radiation protection in France in 2022 349 • 13 • Decommissioning of Basic Nuclear Installations 13 01 07 08 AP 04 10 06 12 14 03 09 05 11 02
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