Abstracts ASN Report 2019

Residual radioactive gases, in particular krypton and tritium, are checked before being released into the atmosphere. The liquid effluents are processed and generally recycled. After verification and in accordance with the discharge limits, certain radionuclides, such as iodine and tritium, are sent to the marine outfall pipe. The others are sent to on-site packaging units (solid glass or bitumen matrix). The solid waste is packaged on-site, either by compacting, or by encapsulation in cement, or by vitrification. The solid radioactive ŊĴņŇĸ ĹŅłŀ ŇĻĸ ŅĸŃŅłĶĸņņļŁĺ łĹ ņŃĸŁŇ ĹňĸĿ ĴņņĸŀĵĿļĸņ ĹŅłŀ ŅĸŁĶĻ reactors is, depending on its composition, either sent to the low and intermediate-level, short-lived waste (LLW/ILW-SL) repository at Soulaines (see chapter 14) or stored on the Orano Cycle site at La Hague, pending a final disposal solution (in particular the CSD-V and CSD-C waste packages). In accordance ŊļŇĻ ŅŇļĶĿĸ єׇӈӇӅіӅׇłĹ ŇĻĸ ŁʼnļŅłŁŀĸŁŇ łķĸё ŅĴķļłĴĶŇļʼnĸ 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 Ӆׇ ĶŇłĵĸŅ ӅӃӃӋє ׏ِ ג IɖƺǼ ƬɵƬǼƺ ƬȒȇɀǣɀɎƺȇƬɵ ǣȇ Ɏƺȸȅɀ Ȓǔ ȇɖƬǼƺƏȸ ɀƏǔƺɎɵ ƏȇƳ ȸƏƳǣƏɎǣȒȇ ȵȸȒɎƺƬɎǣȒȇ The "nuclear fuel cycle" comprises the fabrication of the nuclear fuel used in the nuclear power plant reactors, its storage and its reprocessing after irradiation. Several licensees are involved in ŇĻĸ ĶŌĶĿĸѓ ŅĴŁł ŌĶĿĸё ŅĴŀĴŇłŀĸё ĴŁķ ŁķŅĴє ASN monitors the overall consistency of the industrial choices made with regard to fuel management and which could have consequences for safety. In this context, ASN periodically asks Ňł ņňĵŀļŇ Ĵ Ѣ ŌĶĿĸ ŀŃĴĶŇѣ ĹļĿĸ ŃŅĸŃĴŅĸķ ĽłļŁŇĿŌ ŊļŇĻ ŇĻĸ fuel cycle stakeholders and presenting the consequences –for ĸĴĶĻ ņŇĸŃ łĹ ŇĻĸ ŁňĶĿĸĴŅ ĹňĸĿ ĶŌĶĿĸ҂ łĹ ѡņ ņŇŅĴŇĸĺŌ ĹłŅ ňņĸ łĹ the different types of fuel in its reactors. The last “Cycle Impact 2016” file, for the period 2016-2030, ŃŅłķňĶĸķ ļŁ ĶłĿĿĴĵłŅĴŇļłŁ ŊļŇĻ ŅĴŀĴŇłŀĸё ŅĴŁł ŌĶĿĸ ĴŁķ Andra, more particularly identifies the maximum thresholds (capacity saturations, maximum isotope content of fuel reached, etc.) foreseeable until 2040, on the basis of various energy mix scenarios. This update comprises a number of innovations with ŅĸņŃĸĶŇ Ňł ŇĻĸ ŃŅĸʼnļłňņ ĴŃŃŅłĴĶĻĸņ ļŁļŇļĴŇĸķ ļŁ ӄӌӌӌׇĴŁķ ӅӃӃӉѓ Ҋ The study period, which habitually covered ten years, was increased to fifteen years, in order to take account of the time actually observed in the nuclear industry for designing and building any new facilities identified as being necessary for implementation of the strategy. Ҋ Radioactive substances transport contingencies were explicitly taken into account. Ҋ Nuclear reactor closures were studied for the period of time considered, in particular assuming stable electricity demand until 2025, to take account of the planning provisions included ļŁ ŇĻĸ ŁĸŅĺŌ ŅĴŁņļŇļłŁ ĹłŅ ŅĸĸŁ ŅłŊŇĻ ĶŇ ӅӃӄӈіӌӌӅׇłĹ ӄӊׇ ňĺňņŇ ӅӃӄӈє Ҋ The strategy for managing and storing spent fuels pending reprocessing or disposal was explained. ĹŇĸŅ ĸŋĴŀļŁĴŇļłŁё ķĸĿļʼnĸŅĸķ ļŇņ łŃļŁļłŁ łŁ ӄӋׇ ĶŇłĵĸŅ ӅӃӄӋё the main conclusions of which are as follows. ASN considers that the “Cycle Impact 2016” file provides a satisfactory presentation of the consequences of the various nuclear fuel cycle scenarios on the nuclear facilities, transport operations and waste. However, the consequences of the unforeseen events which could affect the operation of the cycle need to be studied in greater depth. ASN underlines the need to anticipate any strategic change in the functioning of the fuel cycle by at least ten years so that it can be designed and carried out under controlled conditions of safety and radiation protection. It is a question, for example, of ensuring that –given the incompressible development times for industrial projects– the needs for new spent fuel storage facilities or for new transport packaging designs are addressed sufficiently early. łŅ ŇĻĸ ĶłŀļŁĺ ķĸĶĴķĸё ļŇ ŊłňĿķ ŁłŇĴĵĿŌ ĴŃŃĸĴŅ ŇĻĴŇ Ňł Ĵʼnłļķ reaching the maximum capacity of existing storage facilities too quickly (spent fuel pools at NPPs and at La Hague facilities), any reduction in output by reactors consuming MOX fuel must be accompanied by a reduction in that from reactors consuming fuel obtained from Enriched Natural Uranium (ENU), so that all ENU spent fuels are reprocessed. In the longer term, it will be necessary either to have new storage capacities that are significantly greater than the current and projected capacities, or to be able to use MOX fuel in reactors łŇĻĸŅ ŇĻĴŁ ŇĻĸ ӌӃӃׇ ĸ ŅĸĴĶŇłŅņё ŊĻļĶĻ ĴŅĸ ŇĻĸ łĿķĸņŇє Ļĸ Ňļŀĸі frame required for the design and production of these options is about ten years. ASN therefore asks the industrial players to start examining these two options without delay. ʼnĸŅŌ ӈׇŌĸĴŅņё ŇĻĸ łʼnĸŅŁŀĸŁŇ ňŃķĴŇĸņ ŇĻĸ ňĿŇļіŌĸĴŅ ŁĸŅĺŌ Plan (MEP). The functioning of the nuclear fuel cycle could evolve according to the orientations thus defined in this plan. ASN therefore asks the industrial players to study the safety and radiation protection consequences of implementing the MEP on the nuclear fuel cycle and its consistency at each of its revisions. ňŅŇĻĸŅ Ňł ŇĻļņ ĸŋĴŀļŁĴŇļłŁё ŇĻĸ ŌĸĴŅ ӅӃӄӌׇŊĴņ ŀĴŅľĸķ ĵŌ ņĸʼnĸŅĴĿ events which disrupted the balance of the cycle: Ҋ The Melox plant experienced difficulties in producing MOX ĹňĸĿ łĹ ŇĻĸ ŅĸńňļŅĸķ ńňĴĿļŇŌ ĹłŅ ŇĻĸ ĹĿĸĸŇ łĹ ŅĸĴĶŇłŅņє Ļĸ new production process in fact leads to a greater disparity in the ņļōĸ łĹ ŇĻĸ ķĸŃĿĸŇĸķ ňŅĴŁļňŀ ĺŅĴļŁņ ĴŁķ ŇĻňņ Ĵ ĻļĺĻĸŅ ķļņĶĴŅķ ŅĴŇĸє Ļļņ Ŀĸķ Ňł ŅĸķňĶĸ ŇĻĸ ŁňŀĵĸŅ łĹ ĴņņĸŀĵĿļĸņ in the core of eight reactors. As this situation is likely to last, ļŁ ӅӃӄӌׇĴņľĸķ ĹłŅ ĴňŇĻłŅļņĴŇļłŁ Ňł ĹňŅŇĻĸŅ ŅĸķňĶĸ the proportion of MOX assemblies in the cores of its reactors. ASN is examining this request and will issue a response in 2020. This situation also leads to a lesser consumption of the plutonium produced by the La Hague plants and a larger number of spent fuel assemblies in the pools. The surplus plutonium and non-conforming MOX will eventually have to be consumed. Ҋ A fission products evaporator-concentrator at La Hague has reached a level of corrosion which means that it can no longer be used without restriction until the next annual outage for major maintenance of the plant and must thus be closely monitored until the end of its operating life. łŅĸłʼnĸŅё ŇĻĸ łŇĻĸŅ ŅĸŃŅłĶĸņņļŁĺ ŃĿĴŁŇ ĴŇ Ĵ Ĵĺňĸ Ҏ ӅіӋӃӃҏ had to cease operations for several months owing to corrosion of its dissolver impeller, a part that is vital to the operation of its process. Although this event had no consequences for cycle consistency, it did lead ASN to maintain particular vigilance with regard to management of the ageing of the fuel cycle back- end facilities. These disruptions of the cycle back-end plants confirm the Łĸĸķ ļķĸŁŇļĹļĸķ ĵŌ ļŁ ļŇņ łŃļŁļłŁ łĹ ӄӋׇ ĶŇłĵĸŅ ӅӃӄӋׇĹłŅ ĶłňŁŇĸŅŀĸĴņňŅĸņ ņĻłňĿķ ĶłŀŀļņņļłŁļŁĺ łĹ ŇĻĸ ĶĸŁŇŅĴĿļņĸķ ņŇłŅĴĺĸ ŃłłĿ łĶĶňŅ ĴĹŇĸŅ ņĴŇňŅĴŇļłŁ łĹ ŅĸŁĶĻ ņŃĸŁŇ ĹňĸĿ ņŇłŅĴĺĸ capacity. 318 ASN Report on the state of nuclear safety and radiation protection in France in 2019 ׏׏ ٲ NUCLEAR FUEL CYCLE INSTALLATIONS