RHONE-ALPES

V. EURODIF PRODUCTION (WHICH BECAME A SUBSIDIARY OF AREVA NC)

Purpose/type: "civilian" plant for enriching uranium

Period of operation: since 1979

Process: gaseous diffusion

Raw materials: UF6 from Comurhex

Nominal capacity: 10.8 million separative work units (SWU); could provide enriched uranium for 100 PWR of 900 MWe each, almost twice EDF’s electronuclear park

Production: in 2003 10.6 million SWU; in 2005 10.4 million SWU

"The power of the plant is adjusted according to the season" [CIGEET 30.vi.99]. One may suppose that this means that the plant operates at low power when the price of electricity is high.

The plant went into industrial operation in June 1982. At that time, Eurodif anticipated that the plants would be operational until the year 2000. However, in order to prolong the life of the installation, numerous improvements were made during the 90s. Since 1999, teh Eurodif plant has been the object of a re-evaluation of safety. Following the examination of the re-evaluation by the Groupe permanent dexperts pour les laboratoires et usines December 25, 2000, DSIN formulated several demands: the transmission of files in regard to the risk of a criticality, the resistance of the installation to an earthquake, and accidents (fall of an airplane, leak of liquid UF6). The DSIN "approved the most recent versions of the safety reports and regulations for operations, with the reservation that modifications are to be made within two years"[DSIN 00].

 The shut-down of the gaseous diffusion plant is presently planned for 2012-13. It will be replaced by a centrifuge plant, Georges Besse II, which is scheduled to begin operation in 2009 at reduced capacity.  At full capacity, to be reached in 2016, Georges Besse II will produce 7.5 million SWU/yr.  Construction of the centrifuge plant began in mid-2006  [ NucF 22.x.07].

V.A. Infrastructure

1400 stages are divided into 70 groups of 20 stages each. The 70 groups are arranged within four buildings, connected by technical passages. About 2000 t of UF6 are present in gaseous form in the cascade.

This building is responsible for the reception of the UF6 to be enriched, for quality control and for isotopic adaptation of the products coming from the cascade while passing through Annexe U, and for the dispatch of the enriched and depleted UF6.

This building is responsible for the "entries-departures" from the cascade: feeding in natural UF6 by the "belly", the withdrawal of enriched UF6 at the head, the withdrawal of depleted UF6 at the tail and the purging of impurities. The annex is opposite the main buildings to which it is connected by a technical gallery.

The storage of at least 111,000 t is authorized. In 1990, in exchange for an increase in its authorization, Eurodif confirmed its agreement "to reduce the total quantity of uranium hexafluoride stored starting in 1993 in order to reduce the capacity to 50,000 t in 2005 and to reabsorb it completely at the close of the plant’s operation " [DSIN 90]. Eurodif requested an increase to 120,000 t in 1991, it seems, and DSIN asked it to justify its commitments [DSIN 91].

V.B .Atmospheric effluents

The air from the ventilation system in the cascade is directly released at 70 points. This air is monitored, because during an accident there is a risk of releasing UO2F2

The light gaseous impurities are enriched (in the same way as U235) in the cascade. Thus, during a purge of a cascade, gases like HF, ClF3 and other compounds of fluorine, the vapors of refrigerating materials and uranium compounds are released. At Eurodif the effluents are treated, before release "in Annex U a washing column including an electrostatic filter and a rinse with potassium carbonate."

In 1999 the plant released 3.2 kg of uranium, 1.5 kg of chlorures, and 0.6 kg of fluorures. The total activity released was 0.17 GBq, according to Eurodif [Eurodif 00].

V.C. Liquid effluents

A furnace at Eurodif burns contaminated oils. Other contaminated liquids are treated by Socatri [Con ix.00].

The treatment of purged gas and products used in the plant—for example, the destruction of fluorinated residues—produces liquid effluents. All the effluents with uranium are transported to a treatment station of Socatri. The effluents are treated there by precipitation of the radioelements, which leads to a release of liquid into the Donzère- Mondragon canal (see Socatri under Provence). According to Eurodif, releases into surface waters in 1999 contained 0.2 kg of uranium (0.007 GBq) [Eurodif 00].

V.D. Solid wastes

Solid wastes include:

--sludge produced by the activities above;

--sludge produced by the treatment of cooling water before use, and non-radioactive. 

--used parts including barriers;

--depleted uranium—waste or reusable product, depending on one’s point of view. UF6 containing 159 t of uranium produces 135 t of depleted uranium and 24 t of enriched uranium at 3.25% uranium 235 or an annual reload of a third of a core of a 900 MW PWR reactor [Birraux 94].

Other problems

Consumption of energy. In 1999 Eurodif consumed 14, 900, 000, 000 kWh of electricity and 40,850,000 kWh of industrial gas (equivalent power, [Groupe 00]. At its nominal capacity, Eurodif requires 3000 MWe of power. The four Tricastin reactors generate 3760 MWe when operating at full capacity.

Consumption of water. Eurodif consumes 21 million m3 of industrial water per year. It pumps water from the Donzère-Mondragon canal. About a fourth of this water is released into the canal; the remaining three fourths are released by the cooling towers [Groupe 00].

Enrichment of reprocessed uranium. In the early nineties, Eurodif carried out experiments in enriching reprocessed uranium (Repu). The use of Repu may have increased the difficulty of maintenance operations, of decontamination and of release of effluents, because of the radioactivity of the neptunium, plutonium, and technetium [Gresley 94]. In a gaseous diffusion plant, a great part of the technetium remains fixed in the pipes [Resnikoff 93] while the thallium 228 accumulates in the diffusers [Baetslé 94].

Groundwater pollution. Indications of pollution of groundwater by tetrachlorethylene have been detected by Eurodif, according to the GTC [HC98}. The presence of borium and of ammonia has also been noted [DSIN 00

                                                                                  --last entered August 15, 2007

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