1.1 The “fuel cycle” front-end 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 uranium sesquioxide (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 Georges Besse II UF6 ultra-centrifuge enrichment plant (BNI 168); ∙ the Atlas analysis laboratory (BNI 176); ∙ areas for the storage of uranium and thorium in various forms (BNIs 93, 178 and 179); ∙ 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 of uranium per year, enabling it to reprocess all the uranyl nitrate (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 13). 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 Georges Besse II plant (GB II). It has a production capacity of about 14,000 tonnes 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 Georges Besse II ultra-centrifuge enrichment plant –BNI 168 BNI 168, called Georges Besse II (GB II), for which creation was authorised in 2007, is a plant enriching uranium by means of gas ultra-centrifugation. This process involves injecting UF6 into a cylindrical vessel rotating at very high speed. Under the effect of the centrifugal force, the heavier molecules (containing uranium-238) are separated from the lighter ones (containing uranium-235). By combining several centrifuges, creating a cascade, it is then possible to recover a stream of uranium enriched with fissile U-235 isotope and a depleted stream. GB II comprises two enrichment units (South and North units) and a support unit, the REC II. Enrichment of the uranium resulting from reprocessing, which would require prior authorisation from ASN, is not currently implemented in this plant. The tonnages shown in the diagram correspond to rated operation which has not been observed 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 314 ASN Report on the state of nuclear safety and radiation protection in France in 2021 11 – “NUCLEAR FUEL CYCLE” INSTALLATIONS
RkJQdWJsaXNoZXIy NjQ0NzU=