ASN Report 2017

384 ASN report on the state of nuclear safety and radiation protection in France in 2017 Chapter 13  - Nuclear fuel cycle installations the toxic risk. These topics will be the subject of requirements contained in the ASN resolution planned for the beginning of 2018 and defining the conditions in which BNI 98 can continue to operate. The Cerca nuclear fuel fabrication plant – BNI 63 This plant is one of the oldest French nuclear facilities still in service. Work to ensure the conformity of the facility has started and work to improve the containment of radioactive substances and management of the earthquake and fire risks in the main building has been carried out. For this purpose, the licensee sent an authorisation application to ASN for the construction of a “new uranium zone” (area in the main building in which the uranium is in powder form) in accordance with the existing requirements, for which commissioning would be envisaged in October 2022. Compliance with ASN resolution 2015-DC-0485 of 8th January 2015, which requires that the licensee reinforce the facility by the end of 2017, was verified during the examination of the review file, notably during site inspections. 1.2 The back-end fuel cycle - reprocessing 1.2.1 Areva NC reprocessing plants in operation at La Hague The La Hague plants, intended for reprocessing of irradiated fuel assemblies from nuclear reactors, are operated by Areva NC. The various facilities of the UP3-A (BNI 116) and UP2-800 (BNI 117) plants and of the STE3 (BNI 118) effluent treatment station were commissioned from 1986 (reception and storage of spent fuel assemblies) to 2002 (R4 plutonium reprocessing facility), with most of the process facilities entering service in 1989-1990. The Decrees of 10th January 2003 set the individual reprocessing capacity of each of the two plants at 1,000 tonnes per year, in terms of the quantities of uranium and plutonium contained in the fuel assemblies before burn-up (in the reactor), and limit the total capacity of the two plants to 1,700 tonnes per year. The limits and conditions for discharges and for water intake by the site are defined by two ASN resolutions of 22nd December 2015. Areva asked for an increase in the storage capacity for standard vitrified (CSD-V) and compacted (CSD-C) waste packages within the UP3-A plant, which was authorised on 7th November 2016. The authorisation issued by ASN defined the maximum storage duration, beyond which the conditions for this storage must be publicly reanalysed. Operations carried out in the plant The reprocessing plants comprise several industrial units, each of which performs a specific operation. There are thus the reception and storage installations for spent fuel, facilities for shearing and dissolving it, for chemical separation of fission products, uranium and plutonium, for purification of the uranium and plutonium and for treatment of effluents and conditioning of waste. When they arrive in the plants, the spent fuel assemblies in their transport casks are unloaded either under water in the spent fuel pool, or dry, in a leaktight, shielded cell. The assemblies are then stored in pools for cooling. Afterwards, the assemblies are sheared and dissolved in nitric acid to separate the pieces of metal cladding from the spent fuel. The pieces of cladding, which are insoluble in nitric acid, are removed from the dissolver, rinsed in acid and then water, and transferred to a compacting and drumming unit. The nitric acid solution comprising the dissolved radioactive substances is then processed in order to extract the uranium and plutonium and leave the fission products and other transuranic elements. After purification, the uranium is concentrated and stored in the form of uranyl nitrate UO 2 (NO 3 ) 2 . It is intended for conversion in the TU5 facility on the Tricastin site into a solid compound (U 3 O 8 ), called “reprocessed uranium”. After purification and concentration, the plutonium is precipitated by oxalic acid, dried, calcined into plutonium oxide, packaged in sealed containers and placed in storage. The plutonium is then intended for the fabrication of MOX fuels in the Areva NC plant in Marcoule (Mélox). The effluents and waste generated by the operation of the plants The fission products and other transuranic elements resulting from reprocessing are concentrated, vitrified and packaged in standard vitrified waste packages (CSD-V). The pieces of metal cladding are compacted and packaged in compacted waste packages (CSD-C). The reprocessing operations described in the previous paragraph also use chemical and mechanical processes, the operation of which generates gaseous and liquid effluents as well as solid waste. The solid waste is packaged on-site, either by compacting, or by encapsulation in cement. The solid radioactive waste from the reprocessing of spent fuel assemblies from French reactors is, depending on its composition, either sent to the low- and intermediate-level, short-lived waste repository at Soulaines (see chapter 16) or stored on the Areva NC site at La Hague, pending a final disposal solution (in particular the CSD-V and CSD-C waste packages). In accordance with Article L. 542-2 of the Environment Code, radioactive waste from the reprocessing of spent fuels of foreign origin is shipped back to its owners. It is however impossible to physically separate the waste according to the fuel from which it comes. In order to guarantee fair distribution of the waste resulting from the reprocessing of the fuels from its various customers, the licensee proposed an accounting system to track items entering and leaving the La Hague plant. This system, called Exper, was approved by Order of the Minister responsible for Energy on 2nd October 2008. The gaseous effluents are given off mainly during fuel assembly shearing and during the dissolving operation.