RHONE-ALPES

II. COGEMA (SINCE MARS 2006 AREVA NC), CONVERSION AND ENRICHMENT PLANTS

II.A. "Military" plant for the enrichment of uranium

Installations: 4 buildings, according to the level of enrichment

Period of operation: 1964-1996

Process: gaseous diffusion

Raw material: UF6 from Comurhex

Nominal capacity: estimated to be between 2 and 3 t of highly enriched uranium at more or less 20% in 29 years

During the enrichment process, uranium passed from one to the other of four main buildings: low plant (put into operation in 1964, enrichment to 2%); middle plant (1965, at 6-8%); high plant (1966, at 25%); very high plant (1967, at 90% and more).

The low and middle plants were shut down in 1982. In 1984, Pierrelatte began to operate only 7 months of each year. A part of the middle plant was attached to the high plant and put back into operation. In 1990, the installation was constituted of 1328 stages grouped in 89 groups divided up among three plants [Delacroix 90].

The nominal capacity is secret, but the majority of the estimates are around 400,000 and 600,000 SWU/yr. With a capacity of 500,000 SWU/yr, Pierrelatte would have produced about 2.5 t/yr of uranium of military quality if the depleted uranium, the enrichment tails, exited at 0.3% uranium 235 [Albright 97].

During its first years of operation, the plant served only French military ends. Nevertheless, around 1970 France furnished 2 t of enriched uranium to Italy for a critical model of a submarine propulsion reactor [CEANo ii.70]. In 1973, the CEA announced that "a non negligeable part of its activity would henceforth be oriented to civilian ends" [CEARa 72]. The Pierrelatte plant furnished uranium to several foreign clients including Synatom in Belgium, K. K. Kaiser in Switzerland and Escom in South Africa; to the CEA for the Phénix reactor, and to EDF which also bought enrichment services abroad.

In 1980 the high part of the enrichment plant did all its work for the military, and the low plant served as head plant for Eurodif. Eurodif was not yet able to enrich uranium to 3.5%, only to 2.1%. Therefore, the UF6 was transported to Pierrelatte to obtain the necessary enrichment [Comag ii-iii.80]. Eurodif attained its nominal capacity in June 1982 and the low plant was closed that same year.

The replacement of powerful fission heads doped with tritium (the MR-41), which used 75-125 kg of uranium each, with two stage thermonuclear heads, which used relatively little uranium, led to a reduction in the production of high-enriched uranium.

It is probable that the CEA tried to enrich reprocessed uranium in the plant.  In the framework of the American program to return rejects, the enrichment plant at Portsmouth in the United States (Portsmouth Gaseous Diffusion Plant) received from France, between 1972 and 1978, 1.4 metric tons of UF6 containing reprocessed uranium enriched to 56-82% in uranium 235 [Bechtel 00].  This material, if it was enriched in France, could only have been enriched at Pierrelatte.

The uranium that was being used at Tokaimura in Japan, September 30 1999, when a criticality accident occurred, had been "enriched to about 19% for use in a research reactor . . . at Pierrelatte, but before the shut down of the military [enrichment] facilities" [CIGEET 23.xii.99].

It is estimated that Pierrelatte produced in total 9.2 million SWU, with a possible error of plus or minus 30%. The nuclear warheads apart, the enriched uranium was used for civilian reactors, the Célestin, naval reactors and nuclear tests, in total (with a loss of 3%) between 4.0 and 4.8 million SWU, or 22 to 26 t of uranium. These figures would leave about 4.4 to 5.2 million SWU for the nuclear warheads. The warheads, each containing 15-30 kg, absorbed 7.4 to 14.8 t of uranium of military quality [Albright 97].

In 1968, half the gaseous diffusion barriers in use in the low-level plant were replaced with the aim of improving the performance of the plant. Other barriers must have been replaced later. Because of military secrecy, it was impossible to take them out of the plant. At least some of the barriers were buried on the site [see CDRPC 94].

For the other types of wastes, see wastes under Eurodif.

The report of the Groupe de Travail sur la Contamination Radioactive et chimique des Sites INBS (GTC; Working group on radioactive and chemical contamination of INBS sites), published in December 1998, stated that Cogéma had begun rinsing the high and very high plants and carrying out the operation called "macération" with ClF3 (which consists in extracting the uranium hexafluoride that has accumulated in the circuits of the high and very high plants) in preparation for dismantling. Moreover, pilot operations to qualify procedures for dismantling are underway [HC 98]. M. Bataille wrote that the initial work of decontamination is designed " to remove, by ‘trempage’ all the uranium present." (M. Bataille does not seem to have made a clear distinction between "trempage" and "macération.") "The residual uranium thus recovered, and also the uranium already enriched, representing the material in process of fabrication, will constitute a stock available for national defense "[Bataille 97].

During the meeting of the CIGEET, 28 December 1998, Cogéma stated: "An authorization has been obtained from the Safety Authority to begin the dismantling of the low-level plant, the point of departure for the complete dismantling which will take place over a period of five to ten years." At the meeting of the CIGEET, 30 June 1999, Cogéma announced that the "work of dismantling the plant called ‘military’ was already underway.

If reprocessed uranium was used in the cascade, as is likely, the presence of technetium 99 and thallium 28 could make dismantling more difficult (see below Other problems under Eurodif).

The dismantling is expected to cost about 1.8 billion francs [Bataille 97]. According to Cogéma, the defense minister should assume the costs of dismantling [NucF.vii.96]. According to M. Bataille, "The speed of execution of these works will depend on the evolution of the national defense budgets, but there are operations, necessary to assure the safety of the site, that cannot be deferred" [Bataille 97].

In 2000 the installations were the site of a pilot dismantling project.  The wastes stored in place in September 2000 waiting decontamination and packaging consisted of 2707 t of ceramics and metals, of which 650 t had already been decontaminated [Andra 00].

According to the Dam, dismantling should produce the following wastes:

Non-contaminated metals: structural steel, 15,000 t; copper, 700 t

Wastes intended for Andra: 10,000 to 15,000 drums of 200 l each; wastes of less than one Bq/g of activity, 11 700 t

Diffusion barriers (still covered by defense secrecy, they have to remain in place for the moment) [Bataille 97].

However, other wastes will inevitably be added to this list, as for example, contaminated effluents, which are not mentioned there.

II.B. Unité de récupération et d’élaboration des lingots d’uranium (URE; Unit for the recovery and elaboration of uranium ingots)

Purpose: fabrication of uranium metal; treatment of wastes

Installations: three workshops—metallurgy, recovery, decontamination

Period of operation ; since 1966

Processes: conversion by the dry method or the wet method; calciothermy or magnesiothermy

Raw materials: uranium at all enrichments, natural or reprocessed

The mission of the URE is the elaboration of uranium metal from UF6 and "the purification and recycling of uranium present in the various uranium compounds or coming from material treated in URE's various workshops."  Originally the facility transformed into metal, UF6 from the "military" enrichment plants and made highly enriched uranium ingots for the military [Cogéma 94b].  The factory is composed of several workshops, each carrying out specific functions, operated independently of one another, and composed of a certain number of autonomous units.

--Elaboration function:  elaboration of uranium metal and the transformation of various uranium compounds for the purpose of recycling uranium are carried out in three workshops.

--Recycling function:  in the Dismantling Workshop (ADR) and the Workshop  for Treatment and Recovery (ATR) uranium is recovered by means of units for soaking, degreasing, and specific treatments [CogDem 01].  Originally the wastes and rejects came from the "military" enrichment plant. In the nineties, URE also carried out civilian projects. For example, it treated, it seems, nonirradiated fuel fabricated for the HTR reactor at Fort Vrain in the United States. In 1993, Transnuclear sought authorization to send the fuel, a mixture of uranium enriched to 93% and of carburized thorium, to Cogéma’s establishment at Pierrelatte for the recovery of uranium (280 kg) and of thorium (2,481 kg). Cogéma was to return the materials recovered to the United States [USNRC 93a; Booth 96]. 

In 1999 a study of the risk of a criticality at the Tricastin site showed that this risk chiefly concerned  the URE "in which uranium enriched to 20% is manipulated in research reactors" (it is probable that the correct term is "for" and not "in" research reactors) [CIGEET 23.xii.99]

Cogéma's request for an authorization for gaseous and liquid releases, dated March 2001, stated:  "In the near future (the next two years), new missions of recycling highly enriched fuel are going to be entrusted to the URE."  When this happens, the URE will release, in addition to the present effluents, new effluents, the characteristics of which are expected to be the following:  0.3 GBq/yr for .uranium and its descendents, 0.02 GBq/yr for thorium and its descendents."

"The release of flurorure in 1999 was greater than in preceding years because of the start of a program for recovering uranium by the complete dissolution of fluorines that had been stored at URE since 1980.  In 2003, this release should return to a level comparable to those before 1999."  URE released 1555 kg of fluroure in 1999 and 708 kg in 1998 [CogDem 01].

II.C. TU2

Object: transformation of uranyl nitrate into UO2 for fuel and into U308 for storage

Period of operation: since 1986, at the industrial level. The installation was built in 1979-80

Procedure: by the wet method (DUA), modified

Raw material: uranium enriched to less than 1.4% including natural uranium and URT

Nominal capacity: between 600 and 800 t/yr of uranium

Actual production: in 2007 it converted uranyl nitrate from reprocessing, equivalent to 140 t of uranium

The TU2 workshop transforms uranyl nitrate from reprocessing into U308 for storage. For this purpose it has received uranyl nitrate from La Hague since 1986.   The installation converted natural or depleted uranyl nitrate for the manufacture of Mox at CFCa and at Melox.  TU2 has also produced UO2 for Candu reactors [Comag v-vi.90].

In 1999 TU2 produced 130 t of UO2 from depleted uranium and 70 t of U3O8 from reprocessed uranium.  In 2005 and 2006 it operated only in the UO2 configuration.  In 2007 it operated for half the year in the UO2 configuration and for half the year in the U3O8 configuration.  TU2 produced its final UO2 for Mox in 2007 [ Areva. Tricastan 07].   

Cogéma modified the standard wet method in order to produce successively U308, then UO2, instead of UO2 then UF4, and to produce UO2 which flows freely [New no.xi-xii.94]. The main innovation consisted in introducing a dryer with pulverization, which improved fluidity. 

TU2 received depleted uranium for Mox from the Comurhex plant at Malvési.  First, Usine W transformed depleted uranium from Eurodif into U308.  Then Comurhex transformed a part of this U308 into uranyl nitrate at Malvési  for dispatch to TU2 [Bladier 01].  

--revised December 11, 2008

II.D. TU3—shut down

Cogéma mentioned this workshop for the transformation of UF6 into UF4 in a 1991 brochure, but it was shut down before 1993 or during that year [Cogéma 91b; Bonnefoy-Claudet 93].

The nominal capacity of TU3 was 600 t/yr of uranium. The workshop furnished UF4 for the production of "[depleted] uranium metal, sought after for non-nuclear applications because of its very great density" [Cogéma 91b].

II.E. Usine W

Purpose: transformation of depleted UF6 into U3O8 to store and hydrofluoric acid (UF6) to sell

Period of operation: since 1984 (a second part, sometimes named plant W2, began operation in 1992)

Raw materials: depleted UF6 from Eurodif and, in at least 2008, from Urenco

Nominal capacity: since the end of 1992, 17,700 t/yr of uranium oxide and 20,000 t/yr of hydrofluoric acid

Actual production: in 2007, 6,393 t of U3O8; in 2008, 12,889 t of U3O8 (in tU) (in 1999, 13,312 t of U3O8 and 9135 t of hydrofluoric acid)

The plant has always received depleted UF6 from Eurodif.  In 2008 it also received depleted UF6 from Urenco.  The production and the packaging of U3O8 take place in two distinct buildings, the original building and a new building. Each contains two treatment lines. In mid-1999, Usine W had already treated about 195,000 t of UF6 [NucE v-vi.99]. A part of the U3O8 was stored in Parc P19 (below); another part outside of Pierrelatte (see Bessines). In total, 115,461 t of U308 were stored at Pierrelatte in 2002 [DSIN 02].

The hydrofluroic acid produced is "lightly" contaminated with uranium.  

The process is composed of the following two stages:

--vaporization of UF6;

--hydrolysis of UF6 in the presence of water vapor at 250° C to produce uranyl fluoride UO2F2, a solid, and hydrofluoric acid (HF) in the form of gas;

--the pyrohydrolysis of uranyl fluoride in the presence of water vapor at 750°C and hydrogen to produce U3O8, HF, and water vapor;

--the densification and packaging of the U3O8. The cubic metallic containers, with a capacity of 3200 l, constitute the packaging [Cogéma 94a].

The fluoride releases of the Cogéma establishment are principally connected with plant W. In 1987, they represented 23 kg of hydrogen fluoride, but they have decreased and in 1998 amounted to a hundred grams [HC 98].

II.F. P19 Storage Area

Located in two zones to the south of the low-level enrichment plant, the area is composed of seven buildings with a total capacity of 159,000 t of U3O8 containing 134,835 t of uranium.

The prefect’s decree of 16 March 1995 authorizes the storage of uranium that comes "exclusively from plant W," but that can contain 0.01% maximum of U236. Otherwise said, the depleted natural UF6 can be contaminated by reprocessed UF6.

II.G. KF Unit

Intended for the production of anhydrous potassium fluoride, this unit was put into operation in 1989. The raw material consists of 5000 t/yr of HF coming from plant W.

II.H. TU5

Purpose: transformation of uranyl nitrate into U3O8 for storage and into UF4 for fuel

Period of operation: since 1996

Raw materials: uranyl nitrate from La Hague and, at least in 2008, from Marcoule, hydrofluoric acid from plant W

Nominal capacity: 2000 t of uranium

Actual production: in 2007, 1097 t of U3O8; in 2008, 1365 t of U3O8 

II.H.1. THE PROCESSES, WHICH INCLUDE THE FOLLOWING STAGES:

--Production of UF4: reduction of uranyl nitrate by hydrogen in reactors with platinum catalyzers; creation of hydrated UF4 by combining uranium nitrates, HF, and water; filtration, washing, and drying; dehydration and thermal decomposition with anhydrous HF at 500° C;

--Production of U3O8: precipitation of UNH by hydrogen peroxide to create hydrated UO4; filtration, washing, and drying; dehydration and thermal decomposition at 700° C.

The regulations state that the level of U235 must be less than or equal to 1.2% for the fabrication of UF4 and less than or equal to 1.0% for the fabrication of U3O8. According to Cogéma, normal operation, whatever the method, will be at an enrichment of 1% or less [Cogéma 92a].

As of the end of 2006, the configuration of the installation did not allow it to produce UF4 [ASN 06].

II.H.2. AUTHORIZATION FOR RELEASES

The TU5 installation is subject to an annual authorization for gaseous radioactive releases of 100 MBq for uranium isotopes and 250 MBq for other radioelements, including 40 MBq for alpha emitters other than uranium; and to an authorization for chemical releases of 150 mg/m3 of Nox (NO and NO2) [HC 98]. It is subject to an annual authorization for liquid releases of 900 MBq for uranium isotopes, 800 MBq for alpha emitters other than uranium isotopes, and 400 GBq for all other radioelements [JO 11.xi.95].

II.H.3. GASEOUS EFFLUENTS

--hydrogenated effluents exiting from separators after catalytic reduction, UF4 pathway. They are treated in a washing column and the gases are then released.

--process effluents. They are washed, heated, and filtered by two "very high efficiency" filtration stages in series. The levels of uranium, fluorides, and nitrogen oxide are measured before release. The documents at our disposal do not give figures on the effectiveness of the filtration system.

II.H.4. LIQUID EFFLUENTS

The liquid effluents are mostly a matter of liquids that are largely mother waters from filtration. According to the request for modification of the INB, the mother waters are sent to several columns to be distilled. All the liquid effluents, including the water-based effluents from treatment by distillation, consisting essentially of water, uranium, nitrates, and "traces" of fission products, are sent to the Stel, where they are treated and released [Cogéma 92a]. However, the decree of November 1995 authorizing the release of radioactive effluents, provided that for three years certain effluents would be sent to Cogéma’s La Hague establishment [Con xii.97]. In 1999, DSIN authorized TU5 to put into operation an installation for treating the uranium effluents that were formerly transferred to La Hague [DSIN 99].

II.H.5. SOLID WASTES

It is matter of technological wastes and uranium materials caught in filters.

II.H.6. STORAGE OF PRODUCTS

TU5 can use areas P9 and P18, which have a total capacity equal to less than fives years of production at the plant, or less than 10,000 t of uranium. (see below).

The storage area, which existed in 1992, is located to the southeast of Usine W and beside the Stel. The area is "associated with Usine W," but can also store products from TU5 [Cogéma 92??]

Parc P18.

The area, which is located on land near the road that skirts the site on the east, is composed of five buildings. A double row of three levels of U3O8 cubes produced by Usine W surrounds the storage area—in total, 17,749 t of natural uranium, or 20,880 t of U3O8 [Cogéma 92a]. A mound of earth around the entire storage area reduces the radiation. Capacity is limited to 7360 t of either UF4 or U308, from TU5 [JO 24.ix.94].

II.I.A. Parcs d’entreposage P40—planned

According to DSIN, "a project for creating an area called P40, to store civilian material located in the storage areas of the INBs, is under study by Cogéma and could be the object of a demand in 2000" [DSIN 99].

II.I.B. Parcs d'entreposage within the Installation Nucléaire de Base Secrète (INBS) of Areva NP

A decree of January 16, 2009, created two installations within the perimeter of the INBS at Pierrelatte for the storage of materials bearing natural uranium or reprocessed uranium:

--Parc P50 groups the existing storage areas P01, P03, P04, and P17.

--Parc P60 groups the existing storage areas P06, P08, P12, P13, P16 (East and West), P23, and P25.  The uranium bearing materials in P60 are to be removed according to the following schedule:  P12, P13, P16, P23, and P25 by December 2014 and P06 and P08 by December 2016.  The installation P60 must be shut down December 31, 2017 [JORF no. 0040, 17.ii.09].

II.J. L’atelier de "transfert-échantillonage" de l’hexafluorure d’uranim (the transfer-sampling workshop for uranium hexafluoride, TE)

The mission of the workshop is to carry out:

--monitoring by sampling of the containers of UF6;

--isotopic adjustments of the UF6 in the containers to met the specifications of clients;

--transfers of UF6 from one container to another;

--interventions on the packaging [CogDem 01].

The workshop is composed of a transfer building, a sampling building; a zone for storing containers to be treated and a zone for storing treated containers waiting to be dispatched.  The container 48Y for UF6 that is natural or enriched to less than 1% contains 12.3 t of UF6; the container 30B for UF6 enriched to about 3.5% holds 2.2 t of UF6.  The treated uranium can be natural, depleted, or reprocessed, and at all enrichment levels.  

II.K. Maintenance shops

The workshops constitute a group of units that have as their mission:  the decontamination of materiel by aspiration or by dissolution (soaking); repairs of materiel from the point of view of surface quality; repackaging of materiel; and the maintenance of electric and electronic materiel. 

Atelier de démontage rouge (Red dismantling shop, ADR)—maintenance workshops for gaseous diffusion groups.

Atelier de maintenance des conteneurs (Shop for container maintenance, AMC)--This shop includes before and after storage parks.  It receives only uranium enriched to less than 5% uranium 235.

Atelier de décontamination (Decontamination shop, ATD)— In 1998, it was undergoing renovation. The shop was to be used for dismantling and decontaminating diffusion groups from the "military" enrichment units.

Atelier de traitement de surface (ATS)—shop used in the past for applying chrome to metal parts. Like ATD, the shop will be used for the dismantling and decontamination of diffusion groups from the "military" enrichment units.

Atelier de mécanique et de montage (AMM)--shop for mechanics and assembling.

Atelier d'électronique, mesure, informatique (EMI) [HC 98; CogDem 01].

II.L. Technical support installations

These installations include the following units:     

II.L.1. LABORATORY FOR CHEMICAL ANALYSIS, CALLED THE PRINCIPAL LABORATORY (LB)

II.L.2. DES PARCS DE STOCKAGE DES MATIÈRES URANIFÈRES (STORAGE AREAS FOR URANIUM-BEARING MATERIALS)

The establishment of Cogéma has thirteen storage parks, four of which are open and nine covered [CogDem 01].  

II.L.3. LA STATION DE TRAITEMENT DES EFFLUENTS CHIMIQUES (STATION FOR TREATING CHEMICAL EFFLUENTS, STEC)

A single station, operated by Cogéma, treats effluents from CEA Valrho, from Comurhex and from Cogéma,  ie15,000 to 20,000 m3 per year. The effluents are sent by tank truck or pipes to the Stec, which is located to the southeast of the INBS. According to the Groupe de Travail, the effluents undergo "a treatment consisting essentially of neutralization and dilution." The releases are made discontinuously, by batches, into the Donzère Mondragon canal, after monitoring [HC 98; CogDem 01].

The STEC includes five basins for storage/neutralization, including a 400 m3 basin in stainless steel designed for the releases from TU5; two storage tanks for the suspect effluents; two basins for pre-dilution; and four storage tanks for chemical products [CogDem 01].

The muds of the Stec are dried, put into containers, and sent to Andra. Their volume is only about 2 m3/yr [HC 98].

A map shows an "old gravel pit filled by releases in the form of sludges" near the Stec [Cogéma 89]. It is probable that the sludges come from a treatment of effluents carried out in the past.

II.L.4. THE STATION FOR THE TREATMENT OF WASTES (STD)

The station is located to the southwest of the INBS. It is responsible for the collection of solid contaminated wastes and water-based and organic liquids (except for liquid effluents which come from the Stec), treatment, packaging, management, and evacuation of wastes.  The file requesting authorization for releases does not indicate the types of treatment put into practice.  

II.L.5. UNE STATION DE TRAITEMENT [BRÛLAGE] DES HUILES ET SOLVANTS (BHS)--SHUT DOWN

This installation is integrated into the STD and is located in the east zone of the STD.  It has been "shut down since April 1993; it can, however, be put back into operation in the future" [CogDem 01].  The station has as its purpose the burning in a furnace, of contaminated oils and solvents produced by the establishment.  The unit for burning includes a burner of the mechanical grinding type;  the unit for treating gas and smoke is composed of a dust removal apparatus, a system for washing gas, a filtration unit, and a 10-meter-high chimney [CogDem 01].

II.L.6. Station de destruction des récipients et produits dangereux (SDRPD)

II.L.7.  Station de produits inflammables et dangereux (SPID)

II.L.8   Storage of ClF3

The storage of ClF3, for Eurodif, is composed of 500 kg bottles in a building to the south of the Establishment [CogDem 01].

II.M. Wastes

II.M.1. GASEOUS EFFLUENTS

In 1982, Cogéma Pierrelatte filed a request for an authorization for gaseous effluents which, "for questions of administrative procedure," did not succeed. However, limits were fixed on the bases of that request, notified by SCPRI—300 MBq/yr for the isostopes of uranium and 70 MBq/yr for other radionuclides except plutonium [HC 98]. In 1997 Cogéma deposited a new request, with lower limits, for gaseous and liquid effluents, in order that they might conform with decree 95-450 of 4 May 1995. The releases of the INBS will be examined under the authority of the Haut Commissaire à l’Energie Atomique (High Commissioner of Atomic Energy) [Cogémag iv,v,vi 98]. A public inquiry was anticipated in 2001.  Since its entry into service, the civilian installation TU5 has been subject to an authorization that is specific to it.

Before the entry into service of TU5, the gaseous radioactive releases of Cogéma were essentially those of the INBS—or on average several 10 MBq/yr, constituted in part of alpha activity and in part of beta activity. The releases are decreasing. In 1996, the radioactive gaseous releases of Cogéma amounted to 4.2 MBq in uranium isotopes and 1.3 MBq in beta activity [HC 98].

The chemical gaseous releases of Cogéma include especially the fluorides, tied principally to Usine W (see above), and the nitrous vapors coming from TU5.

II.M.2 LIQUID EFFLUENTS

The norms for liquid effluents of Cogéma (and effluents of other companies that go through Cogéma’s Stec) come from a 1996 prefect’s decree that limited the concentration in uranium to 1 mg/l; studies of toxicity carried out by Cogéma; and a 1985 decree relative to installations for treatment of surfaces. In 1997, Cogéma Comurhex, and the CEA Valrho requested authorizations for releases for their respective installations.

In 1999, the Stec released effluents representing in total 14.35 GBq in alpha activity and 5.88 GBq in beta activity. The effluents, which came from Cogéma, from Comurhex, and from the CEA, contained 205 kg of uranium, 111 g of mercury, 2611 kg of fluorides, 3125 kg of ammonia, and 119.6 t of nitrate (including TU5) [CogCP (00)].  Cogéma is the source of the largest alpha emissions from the site [HC 98].  

II.M.3. SOLID WASTES

II.M.3.a. Buried wastes

It is a question of 15,000 m3 of wastes, buried in a mound of earth with an area of 27,000 m2, located to the northeast of the INBS, opposite the canal. The wastes were buried between 1969 and 1976 in a more or less organized manner. The mound in question is now covered with vegetation. It contains:

--760 t of diffusion barriers from the "military" enrichment factory, containing uranium with between 0.6 and 3.5% uranium 235;

--14,000 m3 of fluorine (CaF2) from Comurhex;

--55 m3 of insoluble sludges coming from the Stec nd containing trivalent chrome;

--46 m3 of filters containing less than 1 kg of uranium in total.

Between 2.6 and 3.5 t of uranium would have been present initially in these wastes, half in the fluorines and half in the diffusion barriers.

In 1997, the authorities discovered that the mound had contaminated the groundwater, since the Gaffière, a brook that flows across the site, and a well belonging to Comurhex, had abnormally high levels of uranium and fluorine ions. Starting in 1980, the levels of uranium and fluorine reached 1 mg/l in the well and 50 micrograms/l in the Gaffière. A pump was then put in place by Comurhex (in well P15) in order to extract contaminated water and to release it into the canal (via the establishment’s rainwater network.) In 1995, the levels of uranium in the exhaust water had gone back down to 9 micrograms/l.

In 1997 and 1998, at the request of the Haut-Commissaire à l’énergie atomique, Cogéma carried out a study in the characterization of the residual material in the mound as well as a hydrogeological study. The study reached the following conclusions, among other things,: 900 kg of uranium had left the mound via underground water; the 1700 kg that remained would not be leachable; and the pumping at well P15 at the Comurhex site apparently decreased the level of uranium in the groundwater. However, the study also insisted on the importance of complementary studies, which should be carried out in order to determine the origin of the uranium remaining in the underground water. This uranium was on the order of ten micrograms per liter in the proximity of the Comurhex establishment instead of a microgram per liter in the natural state, and could come from the mound or from the Comurhex building itself [Con viii.99].

Cogéma does not believe that excavation of the buried material would be justified, but it is looking into the covering of the mound and the mechanical stabilization of the sections containing the diffusion barriers.

II.M.3.b. Other wastes

Andra’s 2000 inventory enumerates various wastes placed on Cogéma’s site. They are, for the most part, contaminated with uranium and represent in total about 9 GBq of activity. Cogéma’s wastes awaiting evacuation to the CSA or destruction by incineration (17 m3 of oil and 1115 m3 of solvents). The wastes of FBFC, Comurhex, and the CEA Valrho are awaiting packaging by Cogéma before delivery to Andra.

                                                                                                                              --last entered February 19, 2009

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