ASN Report 2022

Tricastin uranium-bearing material storage yards, P35 and FLEUR Following the delicensing of part of the Pierrelatte DBNI by decision of the Prime Minister, the Tricastin uranium-bearing materials storage yards (BNI 178) have been created. This facility groups the uranium storage yards and the new emergency management premises of the Tricastin platform. Following on from this delicensing process, facility “P35” (BNI 179) was created. It comprises ten uranium storage buildings. A complementary storage facility called “FLEUR”, for which the DAC underwent a public inquiry from 2 November 2020 to 3 December 2020, was authorised by Decree on 18 March 2022. Commissioning of this new BNI 180 was authorised by ASN resolution 2023-DC-0750 of 3 January 2023. The overall level of safety of BNIs 178 and 179 was satisfactory in 2022. ASN notes that the licensee’s action plan for the periodic safety review of the storage yards is being followed very closely. In 2022, ASN inspected the end of the construction of the first two additional storage buildings associated with the FLEUR project. ASN approved the baseline safety requirements for the emergency management building and its equipment. Tricastin Operational Hot Unit The Tricastin Operational Hot unit (BCOT) constitutes BNI 157. Operated by EDF, it was intended for the maintenance and storage of equipment and tooling, fuel elements excluded, originating from contaminated systems and equipment of the nuclear power reactors. In a letter dated 22 June 2017, EDF declared final shutdown of the BCOT in June 2020. The storage activities and maintenance operations are now carried out in its Saint-Dizier maintenance base. The last operating activity consisted in finishing cutting up the used fuel cluster guide tubes from the PWRs operated by EDF. The decommissioning authorisation application is currently being examined. The public inquiry ran from 15 February to 17 March 2022. ASN considers that the level of safety of the BCOT is on the whole satisfactory. In 2023, ASN will be attentive to compliance with the applicable baseline for conducting the ongoing decommissioning preparation operations until 2024, pending issuing of the decommissioning decree. ROMANS-SUR ISÈRE SITE On its Romans‑sur‑Isère site in the Drôme département, Framatome operates BNI 63-U, baptised “Nuclear fuel fabrication plant” resulting from the merging of two BNIs, namely the unit fabricating fuel elements for research reactors (formerly BNI 63) and the unit fabricating nuclear fuel for the PWRs (formerly BNI 98). Framatome nuclear fuel fabrication plants The fabrication of fuel for electricity generating reactors involves the transformation of UF6 into uranium oxide powder. The pellets fabricated from this powder in Framatome’s Romans‑sur‑Isère plant, called “FBFC”, are placed in zirconium metal clads to constitute the fuel rods, then brought together to form the assemblies for use in the NPP reactors. In the case of experimental reactors, the fuels are more varied, with some of them using, for example, highly-enriched uranium in metal form. These fuels are fabricated in the Romans‑sur‑Isère plant called “Cerca”. The “Cerca” plant includes building F 2, which houses the “uranium zone” in which compacted powder cores placed in aluminium frames and plates are produced. The licensee has undertaken to replace this uranium zone by a new uranium zone called “NZU”, in order to improve more specifically the containment of the premises, the process and the prevention of risks in the event of an extreme earthquake. The NZU construction work began in late 2017. These new buildings shall accommodate the current activities of the uranium zone of building F 2. Construction of the NZU continued in 2022, notably with the manufacture and installation of new equipment and performance of the first operating tests. The update of the safety analysis report and the new RGEs associated with the NZU were submitted to ASN in the first half of 2021, leading to complementary information requests on its part. With regard to the progress of the NZU project, due to technical problems and the impact of the Covid-19 pandemic, Framatome requested partial commissioning of the NZU (for the material storage premises only), to allow transfers of materials between the MA2, F 2 and NZU buildings, for which ASN issued an authorisation in October 2022. A request for a modification of the Order of 22 June 2000 regulating water intakes, discharges and environmental monitoring of the Romans‑sur‑Isère nuclear site was also submitted to ASN in July 2020. This request follows on from several changes, including the increase in the production capacity of the FBFC, the stopping of certain activities, the changes made to the liquid effluent treatment facilities, and the changeover from continuous discharging of liquid effluents to discharging via tanks. This case led to two ASN resolutions which came into effect in December 2022: the first setting the environmental discharge limits, the second setting requirements relative to the conditions of effluent discharge, water intakes and consumption and environmental monitoring. In substance, these new resolutions reinforce the regulation of discharges by improving environmental monitoring, the regulation of chemical gaseous discharges and a lowering of the preceding maximum discharge values except for fluorine and hexavalent chrome, for which the absence of significant environmental impacts has been demonstrated. A substantial modification request submitted for FBFC in December 2020 aims to allow increased production of fuels based on enriched reprocessed uranium. It is currently being examined by ASN. 44 ABSTRACTS – ASN Report on the state of nuclear safety and radiation protection in France in 2022 Regional overview of nuclear safety and radiation protection • AUVERGNE‑RHÔNE‑ALPES •