Abstracts ASN Report 2021

Melox plant Created in 1990 and operated by Orano Recyclage, the Melox plant (BNI 151) produces MOX fuel which consists of a mix of uranium and plutonium oxides. ASN considers that the level of nuclear safety and radiation protection is satisfactory on the whole, particularly in the areas of maintenance, control of the fire risk, management of internal authorisations and the management of waste and the cooling functions. The effectiveness of the containment barriers is maintained at a satisfactory level. Breaks in containment, which can occur under normal operating conditions, are subject to specif ic monitoring and measures to limit them. As one of the identified causes of these ruptures is the perforation of gloves in glove boxes, the licensee has developed specif ic reinforced gloves. In addition, for several years now the licensee has had difficulties in producing the planned quantities of fuel in accordance with the safety specif ications of the nuclear reactors. These difficulties seem to originate from the characteristics of the uranium powders used. The licensee has therefore decided to qualify a new type of powder whose production requires the creation of a new facility situated on Orano’s Malvési site (see chapter 11 of the full ASN Report). This situation results in the production of a large quantity of fabrication rejects which are sent to La Hague for interim storage, leading in the short term to the site’s plutonium storage areas being filled to maximum capacity. If these difficulties continue, they could have major consequences for the fuel cycle as a whole. This issue was discussed with the ASN Commission at the hearings of 28 September 2021 and 10 February 2022. This situation induces significant maintenance needs at Melox, which have consequences in terms of radiation protection, with a growing reliance on outside contractors and a very high collective dosimetry. The solutions envisaged at present to improve this situation in the facility consist firstly in thoroughly cleaning the glove boxes to reduce the ambient dose levels, and secondly in deploying a major maintenance programme, with the aim of restoring the level of availability of the production tools. With this aim in view, research and development work has started on the processes for cleaning the facility equipment and on the materials to protect the workers. More particularly, the dosimetry at the lens of the eye remains high. Substantial research and development work has led to the gradual introduction of ergonomic radiation-proof glasses, adapted to the sight of the workers (including outside contractor employees), with the aim of complying with the new downwardly-revised regulatory limits. Furthermore, a vast Machinery Repair Programme (PPRM project) began in 2021. Construction of the emergency centre has fallen behind schedule for reasons linked to the technical and contractual difficulties encountered. At the request of the licensee, ASN has modif ied the requirement of the resolution concerning the deadline for commissioning of the emergency centre accordingly, which is now set at 2023. Centraco plant The Centraco plant (BNI 160), was created in 1996 and is operated by Cyclife France, a 100% subsidiary of EDF. The purpose of the Centraco plant is to sort, decontaminate, reuse, treat and package –particularly by reducing their volume– waste and effluents with low and very low levels of radioactivity. The waste resulting from the plant’s processes is then routed to Andra’s CSA repository. The facility comprises: • a melting unit, melting a maximum of 3,500 tonnes of metallic waste per year; • an incineration unit, in which the incinerable waste is burned, with a maximum of 3,000 tonnes of solid waste and 2,000 tonnes of liquid waste per year; • and storage areas. ASN considers that the level of safety of the facility is satisfactory on the whole, particularly with regard to meeting commitments, deviation management, water take-ups and effluent discharges, and the monitoring of discharges and the environment. ASN does however note an increase in the number of significant events reported in 2021. A new version of the On-Site Emergency Plan (PUI) was authorised by ASN in April 2021, to render it compliant with resolution 2017-DC-0592 of 13 June 2017 relative to the obligations of BNI licensees regarding emergency situation preparedness and management. Furthermore, Cyclife France sent ASN modification requests for its facility in 2020 to allow the treatment of particular types of waste in Centraco, with specific sorting put in place for this waste. ASN considers that the technical and organisational provisions presented by the licensee for this prior sorting operation in dedicated units are satisfactory in principle, but double-checking of the conformity of the waste introduced into the incineration or melting furnaces must be maintained without fail. ASN thus modif ied the requirements of ASN resolution 2008‑DC‑0126 of 16 December 2008 through resolution CODEP-CLG-2022-003400 of 19 January 2022. The monitoring and control of ageing of the facility, especially as concerns the fire-risk protection equipment, are one of the major challenges of the periodic safety review, the conclusions of which were submitted by the licensee in 2021. In 2021, the licensee more specifically implemented corrective measures to prevent the risk of jamming of the incineration furnace waste introduction chamber flaps further to a f ire outbreak in this chamber in 2020. ABSTRACTS – ASN Report on the state of nuclear safety and radiation protection in France in 2021 87 REGIONAL OVERVIEW OF NUCLEAR SAFETY AND RADIATION PROTECTION OCCITANIE