Abstracts ASN Report 2019

ȵǣɎ ɯǣɎǝ ɯƏɀɎƺ ȵǣƬǸ ٮ ɖȵ ɎȒȒǸ ȵǼƏƬƺ Ȓȇ ژגא hɖȇƺ א ׎׏ ژח ƏȇƳ ǔǣǼǼǣȇǕ of the first drum began at the end of 2019. ASN inspected the future licensee’s preparation of the waste retrieval facilities ǣȇ א ׎׏ ژח ƏȇƳ ƬȒȇɀǣƳƺȸɀ ɎǝƏɎ Ɏǝƺ ȒȸǕƏȇǣɀƏɎǣȒȇ ǣȅȵǼƺȅƺȇɎƺƳ ǣɀ satisfactory. ASN notes recurrent difficulties when starting the retrieval operations. Orano Cycle must ensure that these difficulties are resolved rapidly in order to ensure waste retrieval in accordance with the requirements of resolution א ׎׏׎ ٮ!(ٮ ׎׏ ח ׎ ژ Ȓǔ ژחא hɖȇƺ א ׎׏׎ً ƏȅƺȇƳƺƳ ǣȇ zȒɮƺȅƫƺȸ א ׎׏ ח ِ HAO silo and SOC (Organised Storage of Hulls) Áǝƺ…ɴǣƳƺ RǣǕǝ ƬɎǣɮǣɎɵ ǔƏƬǣǼǣɎɵ ٢R…٫ zX זژ ׎٣ ƺȇɀɖȸƺƳ Ɏǝƺ ǔǣȸɀɎ steps of the spent nuclear fuel reprocessing process: reception, storage, then shearing and dissolution. The dissolution ɀȒǼɖɎǣȒȇɀ ȵȸȒƳɖƬƺƳ ǣȇ zX זژ ׎ ژ ɯƺȸƺ Ɏǝƺȇ ɎȸƏȇɀǔƺȸȸƺƳ ɎȒ Ɏǝƺ Ȩ גٮא ׎׎ ژ ǣȇƳɖɀɎȸǣƏǼ ȵǼƏȇɎ ǣȇ ɯǝǣƬǝ Ɏǝƺ ɀɖƫɀƺȷɖƺȇɎ ȸƺȵȸȒƬƺɀɀǣȇǕ operations took place. zX זژ ׎ ژ ƬȒȅȵȸǣɀƺɀ ي • HAO North, spent fuel unloading and storage site; • HAO South, where the shearing and dissolution operations were carried out; • the “filtration” building, which accommodates the filtration system for the HAO South pool; • the HAO silo, in which are stored the hulls and end- pieces (fragments of cladding and fuel end-pieces) in bulk, fines coming primarily from shearing, and resins and technological waste from the operation of the HAO ǔƏƬǣǼǣɎɵ ƫƺɎɯƺƺȇ ׏ ژהוח ƏȇƳ ׏ וחח ٕ • the Organised Storage of Hulls (SOC), comprising three pools in which the drums containing the hulls and end- pieces are stored. In 2019, the licensee continued the operations prior to retrieval of the waste from the HAO silo (notably the construction of the future waste retrieval unit) and started the tests important to safety. The legacy fission product solutions stored ǣȇ Ɏǝƺ ³¨I ژא ɖȇǣɎ Ȓǔ Ɏǝƺ Ȩ גٮא ׎׎ ژ ȵǼƏȇɎ For the packaging of the fission products from the reprocessing of the GCR reactor fuels and containing molybdenum in particular (PF UMo), the licensee has opted for cold crucible vitrification. The package thus produced is a standard package of vitrified UMo waste (CSDU). Orano Cycle continued the ȸƺɎȸǣƺɮƏǼ Ȓǔ Ɏǝƺɀƺ ɀȒǼɖɎǣȒȇɀ ǣȇ א ׎׏ ژח ƏȇƳ ƺȇƬȒɖȇɎƺȸƺƳ ɮƏȸǣȒɖɀ unforeseen technical difficulties linked to the use of the cold crucible. ASN will be attentive to the completion of retrieval of these solutions, planned for 2020. Legacy waste retrieval and packaging project deadlines ASN has regulated all the legacy waste retrieval and packaging programmes on the La Hague site by requirements set out in ȸƺɀȒǼɖɎǣȒȇ א ׎׏ ٮ!(ٮג ׎ ژאוג Ȓǔ (ژח ƺƬƺȅƫƺȸ א ׎׏ ג ِ Áǝǣɀ ȸƺɀȒǼɖɎǣȒȇ defines the priorities with regard to the safety of waste retrieval and packaging operations and sets milestones for each of the programmes concerned. The retrieval of this waste has fallen significantly behind the initial schedule and has continued to do so over the last few years. ASN has examined the deadline push-backs requested by Orano Cycle and their justifications; it considers that the delays must be accompanied by compensatory measures to reduce the risk to as low a level as possible, because the buildings in which this legacy waste is stored do not meet current safety standards. ASN thus considers that the waste retrieval and packaging projects must be managed in exemplary fashion and have robust reference frameworks that allow the implementation of rapid retrieval solutions in order to minimise the risks as early as possible. On this account, ASN considers that Orano Cycle must make effective improvements in the management of the retrieval projects for the legacy waste produced by the operation of Ɏǝƺ Ȩ גٮא ׎׎ ژ ȵǼƏȇɎً ȵƏȸɎǣƬɖǼƏȸǼɵ ɎǝȒɀƺ ƬȒȇƬƺȸȇǣȇǕ Ɏǝƺ ɀǼɖƳǕƺɀ ɀɎȒȸƺƳ ǣȇ Ɏǝƺ ³Á0 ژא ɀǣǼȒɀً Ɏǝƺ ɯƏɀɎƺ ǣȇ Ɏǝƺ R…ɀǣǼȒ ƏȇƳ ɎǝƏɎ in silo 130. Áǝƺ ɀƏǔƺɎɵ ǣɀɀɖƺɀ ƏɀɀȒƬǣƏɎƺƳ ɯǣɎǝ ɀǣǼȒ ׏ ב ׎ ژ ³ǣǼȒ ׏ ב ׎ ژ ɯƏɀ ƳƺɀǣǕȇƺƳ ƏȇƳ ƫɖǣǼɎ ǣȇ ƏƬƬȒȸƳƏȇƬƺ ɯǣɎǝ Ɏǝƺ safety requirements in effect in the 1960’s. Today, the civil ƺȇǕǣȇƺƺȸǣȇǕ ɀɎȸɖƬɎɖȸƺ Ȓǔ ɀǣǼȒ ׏ ב ׎ ژ ǣɀ ɯƺƏǸƺȇƺƳ ƫɵ ƏǕƺǣȇǕ and by a fire that occurred in 1981. Furthermore, part of the waste that was initially stored dry is now submerged in a large volume of water that served to extinguish the ׏ זח ׏ ژ ǔǣȸƺِ Áǝƺ ɯƏɎƺȸ ǣɀ ɎǝƺȸƺǔȒȸƺ ǣȇ ƳǣȸƺƬɎ ƬȒȇɎƏƬɎ ɯǣɎǝ Ɏǝƺ waste and can contribute to corrosion of the carbon steel liner, which at present is the only containment barrier. One of the major risks therefore concerns the dispersion of radioactive substances into the environment (infiltration of contaminated water into the water table). Another factor that can compromise the safety of ɀǣǼȒ ׏ ב ׎ ژ ǣɀ ǼǣȇǸƺƳ ɎȒ Ɏǝƺ ȇƏɎɖȸƺ Ȓǔ Ɏǝƺ ɀɖƫɀɎƏȇƬƺɀ present in the waste, such as magnesium, which is pyrophoric. Hydrogen, a highly inflammable gas, can also be produced by phenomena of radiolysis or corrosion (presence of water). These elements contribute to the risks of fire and explosion. 76 ASN Report on the state of nuclear safety and radiation protection in France in 2019 REGIONAL OVERVIEWOF NUCLEAR SAFETY AND RADIATION PROTECTION NORMANDIE