The plutonium resulting from the reprocessing of uranium oxide fuels is used in the Melox plant operated by Orano in Marcoule, to fabricate MOX fuel which is used in certain 900 Megawatts electric (MWe) nuclear power reactors in France. The MOX nuclear fuels are not currently reprocessed after being used in the reactors. Pending their reprocessing or disposal, the spent MOX fuels are stored in the pools of the La Hague plant. The main material flows for the “fuel cycle” are presented in Table 1 (see previous page). Other facilities are needed for the operation of the Basic Nuclear Installations (BNIs) mentioned below, more particularly the IARU facility (formerly Socatri), which is responsible for the maintenance and decommissioning of nuclear equipment, as well as the treatment of nuclear and industrial effluents from the Orano platform in Tricastin. 1.1 THE FRONT-END “FUEL CYCLE” Before fuels are fabricated for use in the reactors, the uranium ore must undergo a number of chemical transformations, from the preparation of the Yellow Cake through to conversion into UF6, the form in which it is enriched. These operations take place primarily on the Orano sites of Malvési, in the Aude département, and Tricastin in the Drôme and Vaucluse départements (also known as the Pierrelatte site). On the Tricastin site, Orano operates: ∙ the TU5 facility (BNI 155) for conversion of uranyl nitrate (UO2(NO3)2) produced by reprocessing spent fuel at La Hague into triuranium octoxide (U3O8); ∙ the W plant (ICPE within the perimeter of BNI 155) for converting depleted UF6 into U3O8; ∙ the former Comurhex facility (BNI 105) for converting uranium tetrafluoride (UF4) into UF6, which contains the Philippe Coste plant; ∙ the GB II (BNI 168) UF6 ultra-centrifuge enrichment facility; ∙ the Atlas analysis laboratory (BNI 176); ∙ areas for the storage of uranium and thorium in various forms (BNIs 93, 178, 179 and 180); ∙ the IARU facility (BNI 138 – formerly Socatri) which manages waste from the Tricastin site and carries out nuclear equipment maintenance and decommissioning; ∙ a Defence Basic Nuclear Installation (DBNI) which more particularly operates the radioactive substances storage areas, virtually all of which are for civil uses. The TU5 facility and the Orano W plant – BNI 155 BNI 155, called “TU5”, can handle up to 2,000 tonnes (t) of uranium per year, enabling it to reprocess all the UO2(NO3)2 produced by the Orano plant at La Hague, converting it into U3O8 (a stable solid compound able to guarantee safer uranium storage conditions than in liquid or gaseous form). Once converted, the reprocessed uranium is placed in storage on the Tricastin site. The Orano uranium conversion plants – BNI 105 BNI 105, which notably transformed reprocessed uranyl nitrate into UF4 or U3O8, is being decommissioned (see chapter 14). The Philippe Coste plant is located inside its perimeter and is devoted to the fluorination of UF4 into UF6, to allow its subsequent enrichment in the GB II plant. It has a production capacity of about 14,000 t of UF6 from the UF4 coming from the Orano facility in Malvési. It has ICPE status subject to authorisation with institutional controls (“Seveso” class installation) and is monitored by ASN accordingly. The tonnages represented on the diagram correspond to “nominal” operation, which has not been the case in recent years. Reprocessed uranium Spent MOX 110 t Plutonium Reprocessed uranium Fuel fabrication Enrichment 1st conversion Interim storage Spent MOX interim storage Extraction of ore Interim storage pending final disposal MOX fabrication Fission products Technological waste Depleted uranium Nuclear reactor Flows expressed in tonnes/year 7,500 t 940 t 10 t 1,000 t 120 t 1,000 t 120 t 1,000 t 8,500 t 2nd conversion “Fuel cycle” diagram 332 ASN Report on the state of nuclear safety and radiation protection in France in 2023 • 12 • “Nuclear fuel cycle” facilities
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