ASN Report 2017

387 ASN report on the state of nuclear safety and radiation protection in France in 2017 Chapter 13  - Nuclear fuel cycle installations On 4th June 2013, Areva NC requested authorisation to modify the UP3-A plant in order to increase storage capacity: ཛྷ ཛྷ creation of 4,199 additional spaces with the outfitting of pit 40 of the E/EV/LH extension; ཛྷ ཛྷ creation of 8,398 additional spaces with the construction of the E/EV/LH 2 extension, a facility with an identical design to that of the E/EV/LH and comprising two new pits (pits 50 and 60). This modification was authorised on 7th November 2016. ASN authorised the introduction of CSD-V waste packages into pit 40 in November  2017. In April 2017, Areva NC also requested a modification of the UP3-A plant creation authorisation decree so that CSD-C storage could be extended. This application is currently being reviewed by ASN. The special fuels reprocessing unit project With a view to obtaining authorisation to receive and reprocess spent fuels from the Phénix reactor, Areva transmitted a safety options file for a new reprocessing unit at the beginning of 2016. This was in response to an ASN requirement of March 2014 which prescribes the submission of an application before 31st December 2018 for authorisation to modify the facility, which will be the subject of a public inquiry. Areva therefore presented ASN with a project to install a new special fuels reprocessing unit. This unit would comprise new shearing and dissolving equipment, in particular for the spent fuels from test and research reactors and from the Phénix reactor. In March  2017, ASN informed Areva NC that the safety options for this new unit were on the whole satisfactory. ASN considers that the results of the Areva NC activities on the La Hague site are satisfactory enough with regard to nuclear safety, personnel exposure and compliance with environmental discharge limits, while noting that improvements are required with regard to the management and monitoring of handling operations and to the reliability of operational documentation (see chapter  8). 1.3 The back-end fuel cycle: fabrication of MOX fuel The Mélox uranium and plutonium-based fuel fabrication plant BNI 151 Mélox, situated on the Marcoule nuclear site, operated by Areva NC, is today the world’s only nuclear installation producing MOX fuel, which consists of a mixture of uranium and plutonium oxides. In 2017, ASN observed that the safety situation in the facility is on the whole satisfactory. The containment of radioactive substances, radiation protection and criticality risk control issues are dealt with rigorously. In 2016, the licensee applied for authorisation to produce a limited quantity of experimental fuels in order to qualify new types of fuels for possible use in fast neutron reactors. In 2017, it applied for authorisation to conduct a production campaign that could be authorised by ASN in 2018. In 2017, ASN authorised Areva NC to begin construction work on a new emergency management building. 1.4 The back-end fuel cycle: long-duration storage Given the anticipated time-frame identified by the review of the previous “cycle consistency” file, for saturation of spent fuel storage capacity and given the time needed to design and build a new facility, ASN asked EDF to present its strategy concerning this subject. Following on from this, Article 10 of the Order of 23rd February 2017 implementing Decree 2017-231 of 23rd February 2017, implementing Article L. 542-1-2 of the Environment Code and establishing the requirements of the National Radioactive Material and Waste Management Plan (PNGMDR) required that “before 30th June 2017, EDF also send ASN the technical and safety options for the creation of new storage capacity.” In 2017, EDF thus submitted a safety options file for a centralised spent fuel pool project taking account of current safety requirements. This project, for which the location has not yet been decided, should allow storage of spent fuels for which reprocessing or disposal can only be envisaged in the long-term future. The envisaged operating life for this storage facility is about a century. ASN will issue an opinion on these safety options in early 2019. FUNDAMENTALS Mélox and corresponding safety implications The Mélox plant fabricates nuclear fuel referred to as “MOX” (mixture of plutonium and depleted uranium oxides). The plutonium, which comes from the reprocessing of spent fuels at the La Hague plant, is extremely radiotoxic for man. Tthe use of plutonium therefore requires that the licensee take appropriate measures against the risks of dispersion of radioactive substances, criticality and exposure to ionising radiation. In order to control the risk of worker contamination, the licensee carries out the fuel fabrication operations in “gloveboxes” so that the workers are not in direct contact with the plutonium. In addition, “dynamic” confinement is used, on the one hand between the gloveboxes and the rooms housing them and, on the other, between the rooms and the building containing them, in order to reduce the risk of worker or environmental contamination should there be a loss of confinement in a glovebox containing plutonium. In order to control the criticality risk (triggering of an uncontrolled fission chain reaction), «criticality control modes” (control by limiting mass, through geometry, etc.) are implemented. The risk of exposure to ionising radiation is the subject of enhanced vigilance in this facility, given the radioactive materials used there.