POITOU-CHARENTES

Purpose/type: plant for the production of rare earths

Location:  industrial zone of Chef de Baie at La Rochelle (Charentes-Maritime) north of the bay of La Rochelle

Period of operation: since 1947 (activities transferred in 1947 from Serquigny [Eure])

Raw materials: monazite and other minerals

Materials handled: thorium 232, uranium 238

Rhône-Poulenc treated ores-particularly monazite until July 1994-to separate and produce rare earths. The 5 to 6% of thorium 232 that the monazite contains was a byproduct. At present the plant uses raw materials that come from monazite and bastnasite ore, largely purified of radioactivity before it reaches France [Andra 99].

The La Rochelle factory also produced thorium oxide from thorium coming from a Rhône Poulenc plant in the United States [Moody 92] .

Until the end of 1974, the plant released all radioactive liquids and solids directly into the sea. Since, and until the end of 1990, it sent at least a part of the solid residues to the CSM. These wastes are composed, among other substances, of thorium 232, uranium 238, and their descendants (including radium 226 and 228).

Radioactive dusts, thoron, chemical products .

Effluents containing radioactive and chemical products. They were released by a big pipe on the Pont-Neuf beach, and have contaminated the sediments of the bay of La Rochelle and the Pont Neuf beach [Leglu 88].

--A solid residue resulting from the processing prior to July 1994 and described by Andra as “Résidu solide banalisé” (RSB), solid residue made commonplace. As of June 1999, 8025 tons (50% moisture) with an activity of 217 GBq were on the site. The thorium 232 in the dry product represented 48 Bq/g; the uranium 238, 6 Bq/g.  Rhône-Poulenc placed 61,000 t of what Andra describes as RSB into a waste site located near its factory and belonging to the city of La Rochelle (Port de Pallice). The residues contain in particular thorium 232 (48 Bq/g dry product) and uranium 238 (6 Bq/g dry product), for a total of 1.65 TBq [Andra 00]. 

--Radioactive minerals that have not been attacked. According to Andra, they have been used to fill in a part of the plant site;

--Substances in suspension, the only residue produced by the minerals used today. 10,048 t (50% moisture) containing thorium 232 (2.6 Bq/g ) and uranium 238 (4.7Bq/g) for a total of 37 GBq are stored at the plant;

--Tailings, containing thorium 232, uranium 238, and their descendents including radium.  They are more radioactive than the RSB (see above).  They are located at Cadarache and presumably in the bay of La Rochelle.  They were stored for a time at the CSM.  

Andra refused to accept the tailings, starting in 1990, and the prefect refused an authorization to store them on the site. Storage at l’Ecarpière (Loire-Atlantique) was also forbidden. Cadarache finally agreed to store up to 8000 t of tailings [Andra 96]. According to the original agreement, the waste at Cadarache was to be removed between September 1997 and the end of August 1999 [Andra 95]. Following a public inquiry, the duration of the storage has been lengthened.

--Thorium nitrate and crude thorium hydroxide. The 2000 inventory of Andra states in a footnote that it does not take into consideration some 11,000 t of thorium nitrate (mass activity 1650 Bq/g) and about 20,000 t of crude thorium hydroxide (mass activity 720 Bq/g), the “historic” residue of the processing prior to mid-1994, because these substances are “commercialized at present “by Rhodia Terres Rares. The thorium nitrate is used in the manufacture of lamp sleeves; the hydroxide “is a potential raw material.” Apparently these substances are stored at the site [Andra 99]. The 1997 inventory of Andra listed the hydroxide as a waste.

RETURN TO POITOU-CHARENTES