LANGUEDOC-ROUSSILLON MALVESI LIQUID EFFLUENTS -- Water. Rainwater, cooling water, and water coming from valves is sent to a control basin, tested, and discharged into the Cadariège Canal or the Tauran Canal [CLES 25.v.93]. The water released is contaminated mainly with uranium, fluorine, and NO3-, according to Comurhex. The control basin is the bed of the former sulfur mine, with a volume of nearly 2,500,000 cubic meters. This basin receives industrial waste water from the Société Languedocienne Micron-Couleurs as well as from Comurhex; but it is Comurhex that manages the basin [DRILR 00]. In 1999, the basin held 60,000 cubic meters of mud containing 7.6 tons of stable uranium [Andra 99].-- Solutions from the cleansing of nitrous vapors; -- Ammonium nitrate. According to a document provided to the "Commission locale environnement et sécurité (CLES [Local Environment and Safety Commission]), Soferti at Bordeaux uses 4900 t/yr of this byproduct "as fertilizer" [CLES 28.vi.95]. A more recent document states that the "liquids from the precipitation/calcination stage are a very pure ammonium nitrate solution. They are concentrated and used as fertilizer" [DRILR 00]. -- Process effluents. These effluents -- principally the water-based solution coming from the purification shop and containing a little uranium, heavy metals, and other impurities in the form of nitrate -- are sent to the recovery shop, for recovery of the uranium to the extent possible and neutralization with lime. The resulting sludge is then sent to a series of basins. Most of the solids settle in Basins B1 and B2. The liquid is then pumped to the remaining basins. It evaporates little by little under the action of the sun and of the wind [CLES 25.v.93]. Basins B1 and B2 already existed when Comurhex began operation in 1959. Their dikes were composed of waste rock from sulfur mines. They had been used by the sulfur mine, and Comurhex took them over without changing them, although it has since had to repair them to try to prevent leaks. Today they constitute what is in effect a single basin, because the dike that separated them is submerged. Comurhex constructed Basins B3 to B6 in 1975, also on the site of former basins used by the sulfur operation. They were remodeled in 1986-87 and equipped with a lining. At that time B4 became part of B5. (B3 is today dry and no longer in use.) In 1980, B7 and B8 and, in 1995, B9 were constructed to the northeast of the earlier basins according to modern principles [DRILR 98]. B10 was later constructed north of and parallel to B9. B11 was created west of B10 and north of the early basins in February and March 2006 to help to cope with the results of heavy rains. B12, a 3 ha basin, was constructed later in 2006, between B11 and the earlier basins, and was to enter into service in January 2007 [Areva 06]. Andra, in a letter of June 7, 2006, stated that at that time the basins represented a total surface of 26.4 ha and had 5.1 km of dikes . According to Andra, the refinement activity produces 4.5 m3 of effluents for each ton of uranium treated. The annual flow in 1998 amounted to about 49,000 m3 of effluents, concentrated into 19,000 t of nitrate deposits containing 3.2 t of uranium [Andra 99]. The solid deposits in Basins 1, 2, and 3 in 1999 corresponded to about 236,200 t of nitrates and 22,890 m3 of diverse wastes, containing 295 t of uranium. The total activity of the uranium, thorium, and protactinium added up to 45 TBq. Liquid deposits in Basins 5 to 9 corresponded to 49,050 t of nitrates containing less than 52 kg of uranium [Andra 99]. During at least a part of the year water covers the solid wastes. When the water lowers, the drying of the sludge allows winds to pick up particles of toxic and radioactive material. During a storm, when the basins are under water, the wind can carry off drops [MiLi 4.iii.90]. Existence of a leak problem: In 1993 Comurhex admitted that there was a possibility of at least lateral leaks from the basins [CLES 28.ix.93]. A prefectoral decree of 13 September 1995 required Comurhex to obtain a study by a third party of Basins B1 through B6. The Ecole des Mines de Paris to whom the study was entrusted, learned that Basins B1/B2 leak industrial water contaminated by nitrates into the Canal de Cadariège which flows past them. The nitrates end up in the Bages-Sigean pond. A report published in 1999 says that the pond annually receives 380 t of nitrates, 80 t from the leak. Furthermore, around 40 t/yr of authorized and monitored discharges from the plant are added to those of Comurhex in the pond [DRILR 99]. Comurhex was fined 10,000 francs for not reporting the leaks; and a prefectoral decree of 6 November 1998 required Comurhex to undertake research on the leaks and to prevent them. The ANTEA office, called on for assistance by Comurhex, confirmed the leaks into the upper waters, but "assessed the impact on groundwater as small and within the perimeter of the site". It also stated that "the leaks result from the very structure of the basins" [DLILR 99]. The relation between the basins and the groundwater is "not certain," according to ANTEA [CLES 5.v.99]. Comurhex's Remedial Plan : Comurhex undertook a remedial plan, which included blocking and re-routing the Canal de Cadariège to make possible needed work to reinforce the structure of Basins B1 and B2. The Canal carried water from the Oeillal Spring and from the Bassin de Régulation to the Canal de la Robine and thence to the Bages-Sigean pond. A drainage ditch was to be built in the former bed of the Cadariège to catch any leaks from Basins l/2 and send them to the plant’s evaporation basins, which are lined. The rerouting of the Canal de Cadariège was completed in 2001 [Areva 06]. Problems in 2004-2006 with the System of Lagoons March 20, 2004, a dike at the B1 and B2 basins (180 m long by 15 m high) broke, allowing 30,000 m3 of sludge containing uranium, radium, and various chemical products to escape. The flow did not go beyond the property of Comurhex and did not reach the Canal de Tauran [Gaze v.2004; Areva 06]. January 29, 2006, as a result of heavy rains, the zone encompassing the lagoons was flooded with 50,000 m3 of water, but the cells holding the sludge that escaped from B1 and B2 in 2004 and the lagoons did not overflow. Production at the plant was, nevertheless, halted and did not resume until April 1, 2006. March 5, 2006, as the result of a very strong wind the basins overflowed [Areva 06a]. June 20, 2006, in the course of work on the dikes surrounding the lagoons, a pipe carrying effluent from the plant to basin B5 leaked and spilled 350 m3 of radioactive liquid, a part of which contaminated an adjacent train line. The contamination was not found for a month and was reported July 19, 2006 [Crii-Rad 06]. Reinforcement of the Lagoon System Comurhex-Areva announced in November 2006 that it had undertaken a 29-million-euro safety and environmental protection program. The program's seven major projects were rebuilding the dike at the B1 and B2 basins, broken in 2004; removing from temporary storage cells the sludge that overflowed in 2004 and putting it back in basins B1 and B2; strengthening the dikes to all the basins; constructing a 1.2 ha basin to hold up to 35,000 m3 of rain water; testing the effectiveness of covering the basins; and constructing basin 12. All these steps had been completed by November 2006 or were to be completed by the end of the year. . --updated January 24, 2007 copyright © Yggdrasil 2001-2007 | |||