PAYS DE LOIRE

L’ECARPIERE -- shut down

Purpose: production of uranium

An underground mine and three strip mines operated between 1954 and 1990 or 1991. The operation of the strip mines finished before that of the underground mine [RGN iii-iv.94]. They produced 350,000 t/yr of ore [OCDE 83].

Simo-Cogéma carried out heap lixiviation for poor ore (about 0.04%) and treated 4,024,000 t of ore to produce 1240 t of uranium in preconcentrates by the end of 1990 .

Simo exploited the mill from 1957 to 1991. The ore came from mines of the Vendée Division of Cogéma. With a capacity of 650 or 700 t/yr of uranium, the plant treated in total 9,253,000 t of ore at 1.51% to produce 13,423 t of uranium in the form of ammonium diuranate at 75% uranium by the end of 1990 [CEAInf 82; Pradel 82; Desgraupes 91; CEAMin 85].

According to Andra and Desgraupes, about 7,500,000 t of fine tailings and 4,000,000 t of tailings from leaching are on the surface of the site. The fine tailings are stored in the north and south basins and the others in the dikes, basins, and a slope [Andra 99, Desgraupes 91]. The Crii-Rad and J. Pradel of the CEA note the presence of wastes in the underground galleries. According to Andra, the total activity of the tailings is 183 TBq of radium 226. The Crii-Rad estimates a total activity of 889 TBq [Crii-Rad 94a, Pradel 82]. The site, classed as an ICPE, should be an INB, according to the regulations .

In 1992-93, analyses carried out by Crii-Rad on the water draining from the site show that the levels of contamination exceed, in every case, the limits fixed for radioactive releases into the environment .

In 1992-93, according to Crii-Rad, in “the zone of the basins, the levels [of radon] measured exceed 4000 Bq/m3 of air (to be compared with a value off site of 77 Bq/m3, which is already elevated); in the zone that the operator considers remediated, the levels of radon are three times higher than reference levels” [InfoU v-vi.94].

The installations for treating ore have been taken to pieces and the site “remediated.” In 1995, 120 ha of the site were being used for pasture. In spite of protests from ecologists, Cogéma tried to sell 40 ha of a former underground mining zone as well as land from the treatment unit with offices and workshops. The company intends to remain owner of the 80 ha that include the basin where tailings are stored [Ouest 5.x.85]. A project to use the site to store the wastes of Rhône Poulenc was not put into effect.

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