ASN Report 2018

1.1  ̶  The front-end fuel cycle To produce fuels that can be used in the reactors, the uranium ore must undergo a number of chemical transformations, from the preparation of the “yellow cake” through to conversion into uranium hexafluoride (UF 6 ), the form required for enrichment. These operations take place primarily on the Orano Cycle 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 Cycle operates: ∙ ∙ the Comurhex facility (BNI 105) for converting uranium tetrafluoride (UF 4 ) into UF 6 ; ∙ ∙ the Georges Besse II UF 6 ultra-centrifuge enrichment plant (BNI 168); ∙ ∙ the TU5 facility (BNI 155) for conversion of uranyl nitrate UO 2 (NO 3 ) 2 produced by reprocessing spent fuel at La Hague into uranium sesquioxide (U 3 O 8 ); ∙ ∙ the W plant (Installation Classified for Protection of the Environment (ICPE) within the perimeter of BNI 155) for converting depleted UF 6 into U 3 O 8 ; ∙ ∙ areas for the storage of uranium and thorium in various forms (BNI 93, 178 and 179); ∙ ∙ the Atlas analysis laboratory (BNI 176); ∙ ∙ a Defence BNI (DBNI) which more particularly operates the radioactive substances storage areas, virtually all of which are for civil uses; ∙ ∙ the Socatri facility (BNI 138) which manages waste from the Tricastin site and carries out nuclear equipment maintenance and decommissioning. • The TU5 facility and the Orano Cycle 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 (UO 2 (NO 3 ) 2 ) produced by the Orano Cycle plant at La Hague, converting it into U 3 O 8 (a stable solid compound able to guarantee safer uranium storage conditions than in liquid or gaseous form). Once converted, the uranium from reprocessing is placed in storage on the Tricastin site. • The Orano Cycle uranium conversion plants – BNI 105 BNI 105, which notably transformed reprocessed uranyl nitrate into UF 4 or U 3 O 8 , is being decommissioned (see chapter 13). Controlled facilities classified as ICPEs are included within its perimeter and dedicated to the fluorination of UF 4 into UF 6 , so that it can be subsequently enriched in the GB II plant. Each year, they produce about 14,000 tonnes of UF 6 from the UF 4 coming from the Orano Cycle facility in Malvési. Their status is that of an ICPE subject to licensing with institutional controls (“Seveso” installations) and they are subject to the system of financial guarantees for ensuring the safety of the installations and, finally, to Directive 2010/75/UE of the European Parliament and Council of 24 November 2010, known as the “IED Directive” on industrial emissions (integrated pollution prevention and reduction). • The Georges Besse II gas centrifuge enrichment plant – BNI 168 BNI 168, called Georges Besse II (GB II), licensed in 2007, is a plant enriching uranium by means of gas centrifugation. This process involves injecting UF 6 into a cylindrical vessel rotating at very high speed. Under the effect of 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 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. At the beginning of 2009, ASN authorised commissioning of the South unit, comprising eight modules, followed in 2013 by the North unit, comprising six modules, the first two of which are designed to enrich the uranium from spent fuel reprocessing. Enriched uranium Spent MOX fuels 110 t. Plutonium Reprocessed uranium Fuel fabrication Enrichment 1 st conversion 2 d 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 tons/year 7,500 t. 940 t. 10 t. 1,000 t. 120 t. 1,000 t. 120 t. 1,000 t. 8,500 t. Fuel cycle diagram 320  ASN report on the state of nuclear safety and radiation protection in France in 2018 11 – NUCLEAR FUEL CYCLE INSTALLATIONS