ROVENCE-ALPES-COTE-D’AZUR CENTRE DE CADARACHE (CEA-CADARACHE) I. DEVELOPMENT, PRODUCTION, AND TREATMENT OF FUEL I.A Complexe de fabrication des éléments combustibles au plutonium (Complex for the Fabrication of Fuel Elements with Plutonium, CFCa) Objective : production of Mox and treatment of wasteInstallations: Atelier de technologie de plutonium (ATPu) and Laboratoire de purification chimique (Chemical Purification Laboratory, LPC)Operator : CEA until 1991, then CogémaPeriod of operation : 1961-2004Process : formerly Cobroyage Cadarache (Coca); today Micronized Master Blend (Mimas)Raw material : plutonium and uranium oxidesNominal capacity : about 45 t/yr of MoxActual production : in 2003, 16.8 t of fuel rods for Mox; 5.1 t of discards
I.A.2 LABORATOIRE DE PURIFICATION CHIMIQUE, LPC For ATPu, this workshop assures the quality of the pastilles and the treatment of wastes and rejects, especially to recover fissile material. As of 1994, COGÉMA treated separately the "rejects," the "dirty rejects," the "rich rejects" and the ordinary "wastes." The "rejects" were recycled directly at the stage of powder mixing; the "dirty rejects” were treated by chemical means, if necessary by an extraction cycle of the Purex type. A dry procedure was to be put into use in 1995. For this process, the rejects were burned to ashes under a reducing atmosphere and then ground. The powder produced could be added to the fresh powder up to a level of 20%. The "rich wastes" were treated according to type. The cellulose wastes underwent acid digestion. Metallic wastes were washed with freon (because freon destroys atmostpheric ozone, a substitute should now be in use). Wastes that could be ground, after grinding, underwent alkaline washing. The sludge coming from the three processes was sent to a treatment unit for rejects, sometimes after dissolution and filtration or drying. The wastes included sulphuric wastes, contaminated freon, and alkaline wastes [Haas 94]. In 1985 the CEA put into use for the treatment of "rich wastes" a line that included cryogenic grinding. The CEA noted in 1990 that the installation for cryogenic grinding was to be "closed down in 1990, because of problems related to the difficulty in controlling the retention of plutonium in the installation (risk of criticality)" [CEAP 90]. Dismantling of the cryogenic facility is to begin in 2001 and last into 2004 [CEAD 97]. (Despite the treatment facilities at LPC, apparently rejected fuel pellets were placed in stainless steel fuel rods, which were bundled, and sent to La Hague for storage in HAO/Nord [DSIN 97]. )
I.B Workshop for the Treatment of Enriched Uranium (Atelier de traitement de l’uranium enrichi, ATUe)--no longer in operation Purpose : production of UO2 and treatment of wasteOperator : CEAPeriod of operation : 1965-1995, except the incinerator -1997Process : conversion by the dry method and the wet methodRaw materials : UF6, wastes and rejects from other sites Production was stopped in 1995, but the incinerator continued to operate until the end of 1997. In 1994, ATUe was responsible for:--the conversion of UF6 from enrichment plants into compressable UF6; --chemical reprocessing of rejects from the manufacture of fuel rods to recover uranium; --“melting of uranium metal for isotopic adjustments in a liquid medium”; ---incineration of weakly radioactive organic liquids [DSIN 94]. The incinerator, which went into service in 1981, offered in 1988 a 20-50 liter capacity. According to CEA researchers, the facility released less than 3,700 Bq/m3 of gas. It created 7 kg of ashes/m3 of liquids incinerated, except for solvent containing TBP; for TBP, 70 kg/m3 of liquids because of the addition of a calcium salt [Bartoli 88]. It was the CEA’s only incinerator for alpha-contaminated organic liquids [Con x.96].Dismantling is scheduled to begin in 2003 [DSIN 00]. When materials were being moved as part of the preparation for dismantling, 10 g of plutonium were unexpectedly found in a batch of uranium oxide [NucF 25.viii.97]. I.C Laboratoire d’examen de combustibles actifs (Radioactive Fuel Examination Laboratory, Leca) Station de traitement assainissement reconditionnement (Treatment, Cleansing, and Repackaging Station, Star) Purpose : examination, treatment, and packaging of fuel, particularly old fuelOperator: CEA Period of operation : Leca, since 1964; Star, since 1995Process : for old fuel, drying, hydridation, and oxidationNominal capacity : Star, 450 fuel rods/year Leca carries out destructive and nondestructive examinations of UNGG, PWR (in particular, Mox), and fast neutron reactor fuel, and fuel irradiated in experimental reactors at Cadarache. Leca is undergoing major renovation, which began in October 2000. The CEA hopes to be able to use the installation into 2010. The security of the renovated installation was to be reevaulated during 2001, by the Groupe permanent d'experts chargé des laboratoires et des usines (which works with DSIN).Star, an extension of Leca, is intended primarily for the treatment and repackaging of irradiated UNGG . It also carries out destructive and nondestructive examinations of PWR fuel. “[Star] is expected to take over eventually the examinations conducted today at Leca” [DSIN 99]. In September 1998 DSIN authorized the installation of the procedure Fabrice (refabrication of short fuel rods), formerly in Saclay’s Leci, in cell 6 of Leca. [Con xii.98]. Star’s first project is the treatment and packaging of 16 t of old UNGG fuel, stored for more than 25 years in two pools in INB 56 at Cadarache. Processing of the fuel in the two pools should be completed around 2006 [CEAPr 18.xi.99]. Water has entered the interior of the fuel containers and reacted with the uranium metal, creating unstable and pyrophoric products. In Cell C1, the CEA removes the cladding and stabilizes the fuel in a furnace with means for drying, dehydridation, and oxidation of the uranium metal. The stabilized fuel is sealed in containers in aluminum/AG3 alloy, and temporarily stored in a trench in cell C3 and then transported to a reprocessing plant or, since the shut down of UP1, towards the Cascad installation [CNE 98].In the future, Star will carry out special projects, perhaps the stabilization of the fuel from Brennilis. The installation is equipped to receive and to dispatch most types of European containers [défi ix.94]. Thus it will be able to treat fuel from foreign countries. ATMOSPHERIC EFFLUENTS Star is authorized to release 37 TBq/year of radioactive effluents including 3 Tbq/year of tritium. The release of alpha particles is forbidden [JO 31.vii.94]. The disintegration of the surface of UNGG fuel would generate pulverulent uranium contaminated with fission products. The CEA noted in 1994 that cell C1 where the fuel is treated “is expected to be highly contaminated” [CEAD 94]. To achieve zero release of alpha particles, the filtration systems would have to be 100% efficient, a rare if not an impossible achievement. LIQUID EFFLUENTS The “definitive study” notes that water in fuel containers will be quickly eliminated by evaporation in the extraction circuit. This water will be highly contaminated. It will therefore be necessary to use extremely efficient means of filtration.SOLID WASTES For each 450 containers of stabilized fuel elements, the CEA produces 4.5 t of highly contaminated steel wastes from the original containers, 500 kg of magnesium from the cladding, and 30 kg of aluminum alloy from rejected new containers. Maintenance of the cells likewise creates solid wastes [CEA (93?)]. In March 1997 DSIN authorized the storage of magnesium wastes from Star in Cadarache’s Storage Park for Radioactive Waste (INB 56) [Con vi.97]. I.D Atelier de découpage des assemblages combustibles (Workshop for Cutting Up Fuel Assemblies, LDAC) -shut down The workshop monitored and packaged irradiated fuel rods; and carried out neutronography studies for military ends until 1994. In the basement was a neutronography reactor “essentially composed of a vat containing a solution of uranyl nitrate enriched to 93%” [DSIN 92]. In 1991 the CEA emptied the uranyl nitrate solution and sent back to Valduc the solution and the effluents from rinsing the circuits. Likewise, in 1991, the CEA informed the DSIN that three cells that treated fuel would be dismantled in 1994-95. Apparently the workshop was damaged in the explosion during the treatment of sodium from Rapsodie, 31 March 1994. (Rapsodie and LDAC are both part of INB 25.) In May 1995 the workshop was still in a “post-accident context,” and inspectors visited it to make sure of the quality of the dismantling “or” construction taking place [Con viii.95] In March 1997 the CEA informed the DSIN of the final cessation of activities at the Laboratory and of the start of operations that will lead to the final shutdown [Con vi.97]. In 2000 the shop had been cleaned and was awaiting dismantling. In November 2000, DSIN authorized the operation of a laboratory of radioactive metalography, an ICPE located in the same laboratory as LDAC [DSIN 00].I.E Laboratoire d’études et de fabrication des combustibles avancés (Laboratory for Studies and Fabrication of Advanced Fuel, Lefca) Purpose : R&D concerning plutonium-based fuelOperator: CEAPeriod of operation : since 198? ; operation was authorized in 1981Procedure : dry processRaw materials : plutonium, uranium, and minor actinidesNominal capacity : several hundred kg of fuelLefca carries out basic studies on plutonium, uranium, actinides, and their compounds; studies outside the reactor relating to the behavior of fuel in the reactor and in different stage of the fuel chain, and the manufacture of capsules and experimental assemblies. Using dry processes, the laboratory can carry out programs relating to PWR/Mox fuel and those concerning Capra and Spin. Equipment includes an experimental fabrication line and a pilot fabrication line (Inca, New Installation for Advanced Fuel [Installation nouvelle pour combustibles avancés]). Inca is composed of a line for the production of Mox at 1/10 industrial scale. The capacity is several hundred kg of fuel; Inca can manipulate one kg of fissile material [DSIN 92]. PROBLEMS In the last few years, the laboratory has experienced a series of problems relating to the management of fissile material. The most important was observed in July 1997: during the investigation undertaken by the operator, the operator found 170 g of plutonium in a lot believed to contain only natural uranium oxide [DSIN 98; Con vii.98]. After that incident, the activities of the laboratory were stopped , and the CEA began an inventory of material in the laboratory, including the powder store and a store of fuel rods [Con xii.98]. A partial restart of the laboratory was authorized in April 1999 in order to make the inventory possible [Con x.99]. In February 2000, after completion of the inventory, resumption of nominal activity was authorized [DSIN 00]. The safety document transmitted by the CEA in 1996 and 1997 was judged not receivable in 1998 in regard to the earthquake risk. The safety document and the results of the inventory were to be the subject, during 2001, of examination by the Groupe permanent d'experts (working with DSIN). I.F Labo UO2 This laboratory carries out the qualification of UO2 powders and “simulation of certain stages of the process of fabricating Mox fuel while replacing plutonium by other elements (such as cerium).” All the elaboration processes can be tested [Millet 95].I.G Technicatome Workshops Technicatome is the industrial contractor that designs and produces nuclear reactors for submarines and for the aircraft carrier Charles-de-Gaulle. Its means of testing are grouped at Cadarache in the INBS-PN (Propulsion navale)::--prototype reactors (see below) --“halls for mechanical and electrical tests, for the development of various components (….), for assembly, and for the maintenance of embarked equipment” --“ a workshop for the fabrication of fuel for all prototype reactors and for the series equipping the SNLE, SNA, and aircraft carrier Charles-de-Gaulle” [CEACad nd].
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