ILE DE FRANCE-GRANDE COURONNE

CENTRE DAM--ILE DE FRANCE, CENTRE D’ETUDES DE BRUYERES-LE-CHATEL (BEG or B-III)

Purpose/type : research and development center

Operator : Direction des applications militaires (Dam)

Period of operation : since 1956

Materials handled : uranium, plutonium, tritium, deuterium, lithium

The Bureau d’études générales du CEA, responsible for developing a nuclear military program, chose the site of Bruyères-le-Châtel to construct its laboratories. At this center the first plutonium of the Dam was poured June 15, 1959, and the core of the device that exploded in the Sahara February 13, 1960, was made [DAM 88]. The center is reported to have fabricated in total more than 90% of the nuclear devices tested in the Sahara and in the Pacific [HC 98].

In the recent past B-III was oriented towards research and likely no longer fabricated devices exploded at Moruroa. The areas of activity directly related to this guide included studies of materials, in particular nuclear materials, and tasks connected to nuclear testing. The center had laboratories of metallurgy and chemistry, which defined and characterized materials used in the test devices. It prepared the instrumentation to be used in the nuclear tests and, after the tests had occurred, analyzed samples of radioactive material taken from the sites.

As of 1988, Bruyères-le-Châtel managed the stock of uranium 238 for all the centers of the Dam. Cogéma furnished the uranium either directly to Bruyères-le-Châtel or through Sicn. B-III then supplied the other centers of the Dam and also Cerca and Sicn. B-III also took care of residues [Ambolet 88].

Today the role of Bruyères-le-Châtel has changed. The CEA decided in 1996 to reorganize the Dam, due to the end to nuclear testing in the Pacific, a desire to streamline its activities, and the need to move the most dangerous activities involving radioactive materials away from urban areas. The CEA has gradually transferred activities oriented to materials technology from Bruyères-le-Châtel to Valduc (for nuclear materials) and to Le Ripault (for other materials) [HC 98]. According to Christian Bataille, Bruyères-le-Châtel is retaining laboratories for basic research and administrative offices [Bataille 97].  Moreover, it is equipped with powerful computers.  

Bruyères-le-Châtel received personnel from the Vaujours and Limeil centers of the Dam, which closed. The Polygone d'expérimentation de Moronvlliers (PEM) in Pontfaverger (Marne), formerly part of the Centre d'Etudes de Vaujours-Moronvilliers, is now an annex of the Centre Dam--Ile de France. 

The extent to which, or indeed whether, the Centre Dam--Ile de France still handles nuclear materials is not clear. The CEA, in its 1997 annual report, stated that it was regrouping “in a single center in the Parisian region (Bruyères-le-Châtel, B III), the scientific activities at the base of the conception of nuclear charges.” On the other hand, a CEA report on contamination at Bruyères-le-Châtel and three other sites sites noted, “Nuclear activities concerning defense ended [at Bruyères-le-Châtel] in 1997” [HC 98]. 

In 2004, according to the Web site of the CEA/Dam, the Ile de France center is engaged in three fields of activity:

--The nuclear test simulation program.  The center conducts studies in nuclear physics, carries out computer modeling of nuclear explosions, and designs and executes tests without nuclear materials that simulate parts of nuclear weapons explosions at Moronvilliers and at CEA/Cesta.

--Earth and environmental sciences.  The center is the executive agent in France for technical activities in the framework of the Comprehensive Test Ban Treaty and supports nuclear nonproliferation efforts.  The Département d’analyse et de surveillance de l’environnement (Dase) at the center operates an earthquake surveillance network that informs authorities of earthquakes within France. It is also in charge of the seismic stations within France that belong to the surveillance network for the Comprehensive Test Ban Treaty [défi x.99].

--Major nuclear-related projects such as the construction of the Laser Mégajoule and the decontamination and cleaning of Cogéma's enrichment plant at Pierrelatte and the plutonium-production facilities at Marcoule.  The center serves as a source of expertise.

                                                                             --updated 17 May 2004

II. INSTALLATIONS

Installations that might cause contamination

The change in the role of B III entails cleaning up and dismantling buildings and getting rid of much equipment, chiefly glove boxes and a foundry. “Certain equipment will remain in place ‘in mothballs’ in case problems occur in one of the production or reprocessing chains at Valduc. In all likelihood, these zones will not be decontaminated but will remain as they are” [Bataille 97]. A list of the “main potential sources of contamination”at the site indicates the status of installations that handle(d) radioactive materials. The installations are as follows:

A building with hot laboratories handling plutonium, tritium, and lithium hydride. The gaseous releases from this building were the only releases from the center that, during normal operations, contained tritium. The releases were made through two chimneys, each with the ability to evacuate 55,000 m3/hr of air. Beginning in 1978, the Dam worked at decreasing the tritium releases from the building through such changes as installing equipment to remove tritium from glove boxes. The building is being cleaned up and will be dismantled to level 2 on the scale of the International Atomic Energy Agency. Parts of the building that can be taken to pieces will be removed and the confinement zone reduced to a minimum.

A building using plutonium, uranium, tritium, and beryllium. Four chimneys capable of evacuating respectively 24,000, 27,000, 50,000, and 60,000 m3/h of air were responsible for the release of gaseous effluents. During normal operations these effluents were not radioactive, although tritium may at times have escaped. The building is undergoing cleanup and will be maintained under surveillance without dismantling.

A building using various radionuclides: products of fission and transuranics. Gases were released through two chimneys capable of evacuating respectively 25,000 and 30,000 m3/h of air. The releases were only “very weakly” contaminated during normal operations, chiefly with fission gas (halogens). The building is undergoing dismantling to level 2.

The building for the storage of solid wastes containing plutonium and tritium and packed in drums. According to Andra’s 1999 inventory, alpha wastes awaiting dispatch to Andra or Cadarache amount to 96 m3 (1 TBq); tritiated wastes awaiting dispatch to Valduc, 26 m3 (150 TBq). The building is being maintained in an active state.

Laboratory using transuranics, activation products, fission products, and molecules marked with tritium and carbon 14. Gaseous releases pass through a chimney capable of evacuating 37,000 m3/h, and are not normally radioactive. Most activities in this building are carried out for civilian purposes, and it is staying in operation.

Workshop for producing shaped pieces of natural uranium. Gaseous effluents were released through a chimney capable of evacuating 10,000 m3/h and in normal operation were not radioactive. This workshop has been totally dismantled and replaced with a computer center. As of 1998, the center had not furnished detailed information about the radioactivity of the ground after decontamination.

Equipment that includes two particle accelerators that may on occasion be “lightly contaminated,” particularly by tritium .

Building storing, among other wastes, 700 drums containing in total 26 kg of depleted uranium [HC 98].

The Computer Center

In 1997 the CEA created a computer center at Bruyères-le-Châtel with a Cray T90 computer.  The computers installed at the Centre de Limeil-Valenton were in 1999, after Limeil's closure, transferred to Bruyères-le-Châtel [CDRPC Obsan #1].  However, the CEA seems to need more effective machines for its future program to simulate nuclear tests.

The CEA has acquired a supercomputer from the American company Compaq. Named Téra, it is equipped with 2560 processors functioning in parallel.  The maximum power is 5 teraflops; actual sustainable power is 1.4 teraflops.  The CEA intends to replace the individual machines in the supercomputer twice.  "Thanks to computers that are of a new generation and in greater number,"  in 2009 Téra should reach 500 teraflops [défi v-vi.02].  

The CEA constructed an extension of the computer center to the west of the center.  This extension makes it possible to house the means of simulation and storage of information.  The building is underground and is connected to the computer center by two independent galleries [CEAInter ix.99].. Téra is at a depth of 9 meters as protection from electromagnetic emissions [défi v-vi.02].  Four centers of the Dam are able to utilize the computers at Bruyères-le-Châtel by means of electronic links.

                                                                                                              --updated 15.v.04

III. SOLID WASTES

According to the CEA, the solid wastes at Bruyères-le-Châtel are chiefly technological wastes and wastes from dismantling. They are essentially contaminated by alpha emitters and fission products, in particular tritium. In addition in past years, the center has had to store or dispose of highly radioactive samples from nuclear tests.

In the past, at least a portion of the wastes remained at the center. In 1991, Bruyères-le-Châtel “began repackaging [and dispatching] its old wastes.” Today the center dispatches wastes according to the following system:

--to Andra’s Centre de Stockage de l’Aube for final storage: wastes called low activity, category A;

--to Cadarache for temporary storage: waste not accepted at the Aube center, category B;

--to Valduc for treatment: “reprocessable products, rich in nuclear materials,” and for temporary storage tritiated waste [CEAD 97].

This system does not account for the highly radioactive test samples.

As of 1988, B-III managed the Dam’s store of residues of natural and depleted uranium. Valduc has today likely taken over this function. B-III evacuated to Annecy 1) for grilling in an oven, natural and depleted uranium residues free from oil, 2) for remelting, certain ungrillable residues and 3) for compaction, turnings of depleted uranium. It sent old residues covered in oil to another site, probably the polygon of Moronvilliers to be burned in the open air. Alloys rich in uranium, except for alloys of niobium or of molybdenum, could be dissolved in acid at Malvési [Ambolet 88].

As of 1978 the wastes described as “weakly” contaminated were removed by the Sita, a company that manages household waste. During a meeting of the CHS B-III, 28 June 1978, it was “stated that only wastes from hot laboratories are normally monitored by the SPR. For the others, monitoring is much more difficult and would be only occasional. It is to be noted however that all the wastes taken by the Sita are delivered to Tiru and burned like ordinary household wastes. In no case are they put into a public dump.” According to Bataille, so called very weakly contaminated wastes are today stored at the center for lack of anywhere to send them [Bataille 97].

IV. GASEOUS EFFLUENTS

The Journal officiel of 12 May 1995, published an authorization for radioactive releases. “The annual activity of radioactive gaseous effluents . . . must not exceed 1850 TBq (50 kCi) for tritium. These releases must not in any case add to the environment radioelements that are alpha emitters nor activity from gaseous halogens or aerosols.”

Releases of tritium, by far the main gaseous contaminant, peaked at 26 PBq (700,000 Ci) in 1973. In 1997 tritium releases amounted to 300 TBq (8000 Ci). Accidental releases of tritium occurred frequently, with the largest single release reported as 1170 TBq in 1976 [HC 98].

The center released 259 Tbq of tritium as part of a European Community program on fusion reactors 15 October 1986 [LeMo 13.v.87].

The authorization for radioactive releases published 12 May 1995 states in regard to liquids that “added volumetric activity, calculated after total dilution in the waters of the Rémarde must not exceed, in average daily value:

--20 Bq (0.5 nanocurie)/l for tritium;

--10 mBq (0.3 picocurie)/l for all radioelements other than tritium;

--1 mBq (0.003 picocurie)/l for alpha emitters.

The Rémarde, a tributary of the Orge, borders to the south the plateau on which Bruyères-le-Châtel is situated. The brook, the Grand Rué, which begins at the southern edge of the site, flows into the Rémarde. The Grand Rué was an intermittent stream before the construction of the center and is largely fed by water from the center [HC 98].

Radioactive liquids from the processes carried out in the nuclear installations are sent by truck to specialized treatment centers. Until around 1995, they went to Saclay. They have since gone to Cadarache. The change in destination is due to the fact that efforts to decrease the volume of liquid effluents raised the activity for a given volume and necessitated special treatment at Cadarache.

The liquid effluents released by the center are composed of:

--liquids that are banal from the point of view of chemistry and that have a level of radioactivity that “is in general below the limit for release to the public.” They are sent to a “Degremont” station for physical-chemical treatment by means of flocculation and, if needed, specialized treatment;

--“des eaux vannes” purified by biological treatment and treatment in the “Degremont” station;

--rain water and nonradioactive used water, released directly into the environment.

These three types of liquids are released into the Grand Rué and thence to the Rémarde after monitoring [HC 98].

V.C. Contact with groundwater?

The 1998 report of the working group on the contamination of INBSs notes only one incident of contamination of the ground with liquid: a break in a pipe, 28 December 1978, in the building Radiochimie. The water in the pipe contained americium. The CEA believes that the radioactivity remained in place, because measurement of radioactivity in the underground water at a point “downstream” from the incident has not indicated any resulting contamination [HC 98].

The tritium released by the Center has had an impact on the rain water (see below) and therefore on the rivers and groundwater. As a result, the Haut-Commissaire à l’énergie atomique in 1996 requested a study of transfers of tritium in the center’s environment and of the evolution of the tritium in the environment after “nuclear activities concerning defense” have ended [HC 98].

A possible contamination of the center’s surface water would take one of the following paths:

--infiltration directly towards the upper aquifer: that of the sands of Fontainebleau and, immediately below the sands, of the marly limestone of Brie. A small part of the water would be able to penetrate the generally impermeable marl and reach the aquifers below;

--contamination of the Grand Rué. Such contamination would be significant only if the direction of the flow of water in aquifers along the river were reversed as by pumping for agriculture;

--contamination of the deep underground Néocomien aquifer, which is tapped by a well 750 m deep for water for heating and for drinking at the center. An analysis of water from the Néocomien presented at a meeting in 1998 showed alpha activity between 0.15 and 0.20 Bq/l, beta activity of 0.5 Bq/l, and tritium activity less than 0.2 Bq/l. The staff of the center intended as of 1998 to conduct analyses that would show the natural origin of the alpha and beta activity. The center does not reinject into the aquifer the water that it draws from the aquifer. The Néocomien presents a strategic reserve of drinking water for Paris, and is not normally tapped [HC 98].

The level of the water table below B-III may have a bearing on any pollution or possible pollution of the upper aquifer. A hydrographic map indicates that in February 1964, the underground water was 1.07 m below the surface of the ground. During that period “fine clays and sands (sands of Fontainebleau) explain[ed] the condition of the ground, in part gorged with water and its tendency to sway (permanent monitoring [was] conducted there)” [Robert 70-71]. In 1993, the water table was lower, an official of the BRGM at Paris reported. However, the 1991 edition of the Présentation Générale de la Sûreté de l’Etablissement [PGSE] indicates that the aquifer corresponding to the Fontainebleau sands and the Brie limestone “’bathes the foundations of a portion of the center’s buildings’ (to the south-south-east)” [quoted in HC 98].

Samples were taken on the roof of buildings at the site. Alpha activity was 0.1 mBq/m3 in 1990. Between 1995 and 1997 activity increased by a factor of two. The CEA work group on contamination at the site noted that if the trend were to continue in 1998, the cause would have to be found. Beta and gamma activity were reported to be at the level of “natural” background. Tritium activity was 200 Bq/m3 maximum at the site. At 3 km downwind the level in 1998 was several tenths of a Bq/m3 [HC 98]

Between 1982 and 1989 the average annual activity in tritium varied between 100 and 380 Bq/l, but monthly averages could exceed 1000 Bq/l. We do not have more recent figures.

Tritium activity in the Grand Rué was 80 to 410 Bq/l with an average of 200 Bq/l from 1982 to 1997. It increased by 80 to 100 Bq/l between 1995 and 1997. Alpha activity was 0.08 to 0.18 Bq/l from 1982 to 1997; beta and gamma activity, 0.4 to 0.6 Bq/l. Tritium activity in the Rémarde after its juncture with the Grand Rué was 6 to 70 Bq/l from 1982 to 1997. Alpha activity from 1982 to 1997 was 0.03 to 0.09 Bq/l and beta and gamma activity 0.2 to 0.3 Bq/l.

In 1989 the volumetric activity of tritium directly underneath the center was in general between 300 and 600 Bq/l with a maximum of 3700 Bq/l at piezometer 3 (in 1979, piezometer 3 had measured 10,000 Bq/l). At Ollainville, one km to the south of the center, the groundwater contained 600 Bq/l in 1998. Between 1994 and 1997 the level of tritium in the groundwater underneath the center increased noticeably-by a factor of three at piezometer P7 to the south of the center. As of 1998 the reason for the increase had not been identified [HC 98].

In the grass in 1996, the average mass activity of tritium (tritiated water) varied between several Bq/fresh kg and 2000 Bq/fresh kg, with an average of 150 Bq/fresh kg.

Tritium activity in tree leaves sampled in 1989 at the center were approximately a thousand Bq/fresh kg. A map shows a zone of 60 km2 in which activity in terms of organically bound tritium in leaves is greater than 2 Bq/g of hydrogen. The CEA of Bruyères-le-Châtel has made a regional map based on 1996 sampling, that shows tritium measured in the combustion water of oak leaves. It demonstrates that the circles of influence of Bruyères-le-Châtel and Saclay in regard to tritium overlap. In the vicinity of Saclay, levels in the three hundreds of Bq/l were recorded. Close to B-III the level was 1000 Bq/l. A large zone of 100 Bq/l includes both Cen Saclay and B-III [HC 98].

The PGSE mentions, among other things that lithium hydride was used at Bruyères and that lithium wastes were burned in the open air in the 1970s.

The center sends the prefecture each month an account of its monitoring of the center and the surrounding area for toxic chemicals. However, the figures furnished do not cover the main toxic substances and in particular the heavy metals listed in decree 89-3 of 3 January 1989 in regard to water intended for human consumption [HC 98].

The Working Group created by the Haut-Commissaire à l’énergie atomique to evaluate radioactive and chemical contamination at INBSs notes that various studies of the site are underway, for the purpose of making possible a decision on how many supplemental piezometers are necessary to monitor the groundwater. It also notes that although there is no reason to suspect a priori the existence of significant radioactive or chemical contamination as the result of accidents, the following studies should be carried out:

--systematic analysis of radioactive contamination of the ground within the INBS;

--analysis of the levels of the substances listed in decree 89-3 (see above), in liquids released;

--delimitation on a map of tritium contamination of the groundwater.

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