ILE DE FRANCE-PETITE COURONNE

The CEA settled into the fort de Chatillon, part of the old fortifications of Paris, in 1946, a few months after the CEA’s creation. For almost ten years Fontenay was at the center of French nuclear research and development, with the first French atomic pile (Zoé), a pilot reprocessing plant, a workshop for concentrating uranium, and laboratories for the production and analysis of radioelements. At this period the bunkers and defenses of the fort remained intact [CEAPr 99].

In 1956, the CEA envisaged abandoning the site. Instead, between 1958 and 1962, it tore down all the nuclear installations except Zoé, leveled the terrain, and constructed the buildings that exist today, at that time oriented towards the chemistry of plutonium and transuranics, irradiation and examination of nuclear fuel, radiometallurgy, and controlled fusion. In recent years Fontenay specialized in reprocessing, plutonium, waste treatment, protection, and nuclear safety.

In 1995 the CEA terminated nuclear research at Fontenay. Four years later, the CEA announced that it would denuclearize the site, with the intention that it be available for non-nuclear research. The denuclearization is to be completed in 2010. Below, we present key installations from each generation.

Zoé (zero energy, oxide, heavy water); (Eau Lourde 1 [Heavy Water 1], EL-1)--shut down

Type: first French pile

Period of operation: 15 December 1948-1975

Power: originally zero; then 0.25 MW thermal maximum

Fuel: originally natural uranium oxide; then uranium metal

Moderator and cooling fluid: heavy water

Dismantling: to level 2 in 1977; the remaining structure is confined in concrete and constitutes the center of a museum of the atom.

PILOT PLANT FOR THE EXTRACTION OF PLUTONIUM—shut down

Designed originally for the treatment of fuel rods from Zoé, the pilot also had to reprocess the more radioactive fuel from EL2 at Saclay. From January 1954 to December 1957, it operated at a maximum rate of 5-6 kg/h, using the Purex process [Lallement 91; EnNu vii-ix.57]. The necessity of reprocessing fuel from EL2 caused numerous incidents, including a fire in the evaporation workshop [BIST iii.63].

The pilot was dismantled between January 1959 and June 1962 under extremely difficult conditions. No diagram of the installation existed, because it had been modified numerous times, and the pilot was highly contaminated, up to 53,000 times the maximum admissible limit in the plutonium concentration workshop [BIST iii.63]. The CEA admitted in 1990 that the "factory was entirely dismantled and emptied but with the regulations of 20 years ago. The situation must be reexamined in regard to today’s norms."

The wastes from dismantling included 800 t of lead, 400 of which were decontaminated by melting at Saclay, and 17,000 m3 of earth and rubble, of which 15,700 m3 were returned to the public domain. A part, for which the mass activity was near the detection limit, was stored on the Bauzot site (Saône et Loire) (see Bauzot).

In 1955, the CEA drew up regulations for handling liquid effluents and solid waste at Fontenay. In accordance with these regulations, the most radioactive liquids were sent to Marcoule and Saclay for treatment and packaging in the form of solids, presumably in bitumen. Less radioactive liquids were treated by flocculation and decanting at Fontenay and then discharged into a sewer, which carried them to the Achères purification station on the Seine. Solids with an activity of more than 1100 Bq/g went to Saclay and thence eventually to Andra, those with between 11 and 74 Bq/g went to Bauzot (dispatch of waste with 75 to 1000 Bq/g to Bauzot was permitted but not practiced), those with less than 11 Bq/g were put into local public dumps.

Zoé was succeeded by three reactors: Minerve (100 W thermal), Triton (1 MW thermal carried to 6.5 MW thermal), and Néréide or Triton II (600 kW thermal), installed in the pool of Triton. All three were pool piles moderated with heavy water. Triton, and probably also Minerve and Néréide, used laminated fuel with uranium enriched to 93%. Minerve, which entered into service in 1959, was moved to Cadarache in 1977. Triton and Néréide, in use from 1959 and 1960 respectively to 1982, have been dismantled. However, the basin of Triton and Néréide was conserved "as was", in part because of the difficulty of removing it and in part because of the possibility of reusing it to test equipment. Today it contains contaminated ventilation circuits [Lallement 91, Andra 00].

BÂTIMENT RADIOCHIMIE (BÂTIMENT 18)—shut down

Put into operation in 1960, this building was designed for studies in the chemistry of plutonium and transuranics and studies in radiochemistry. It housed the Laboratoire de chimie du plutonium (Plutonium chemistry laboratory. LCPu; INB 57) among other installations. Beginning in 1982, the building was shut down little by little. In 1995 the CEA transferred the activities of LCPu to Atalante (Marcoule).

The building houses:

--some twenty shielded cells with equipment for remote operation, in which very radioactive materials were studied. Walls are of lead or of thick concrete;

--134 glove boxes for handling purified plutonium freed of its fission products;

--a hundred tanks of low-, medium-, and high-activity effluents [CEAPr 26.i.99]

Activities have included:

EXPERIMENTATION IN REPROCESSING BY THE WET METHOD

The laboratory studies were carried out in three stages: inactive tests, alpha tests in the presence of plutonium, and alpha, beta, and gamma tests in the presence of plutonium and fission products. The last were carried out in chains of shielded and tight cells, among them Cyrano, Carmen, and Gascogne.

EXPERIMENTATION IN REPROCESSING BY THE DRY METHOD

The tests were carried out in the cell Attila (ATTaque d’Irradiés-combustibles-en Lits d’Alumine; Attack of irradiated fuel on aluminum beds) in 1996 and in a small cell Clovis [Sauteron 69].

PRODUCTION OF PLUTONIUM 238

In the shielded cell Pétrus, the CEA treated neptunium 237 targets that had been irradiated in the Célestin reactors at Marcoule, to obtain plutonium 238. These operations began "by dissolving the irradiated target in nitric acid and continued with an original process of selective extraction of the different transuranic elements in an organic solvent" [CEANo v.70].

WASTE TREATMENT

In the Elise and Prolixe chains, the researchers treated solid wastes by oxidizing leaching with electrogenerated silver II: Elise was put into operation for alpha wastes in 1987, and Prolixe for alpha and beta-gamma wastes in 1988. Leaching with silver II is used today for waste treatment in UP2-800 at La Hague.

The CEA used the Prodige chain to study the decontamination of certain organic effluents strongly contaminated with alpha and beta-gamma activity [CEAP 90]. The process consists of an alkaline treatment, evaporation, and mineralization in a sulfur medium. The distillate from evaporation was incinerated in ATUe at Cadarache, but the sulphated effluents from the mineralization "pose[d] a disposal problem" [CEAP 90; CEAD 95].

Attila was dismantled by STMI between September 1984 and January 1987 [Terrasson 89]. In 1999-2000 the CEA is sending the last nuclear materials in any quantity at Fontenay from LCPu to Marcoule for use in Atalante [DSIN 99, p. 333].

Cleanup has been going on since 1994 [CEAD 98, p. 64] and is to be finished by 2002. Dismantling is to start in 2002 and end by 2010 [CEAPr 26.i.99]. The dismantling program is expected to produce 5000 m3 of very low-level radioactive wastes; 1500 m3 of low-level waste, and 160 m3 of medium-level waste. Presumably these wastes are solid, and effluents are also produced, but the source does not so state [CEAPr 26.i.99].

BÂTIMENT PLUTONIUM (BUILDING 19)—shut down

Devoted to research on plutonium-based fuel, this building was in use from 1957 to 1984. Activities conducted there were transferred to Lefca at Cadarache, and dismantling to level 3 ended in 1986 [DSIN 93].

LABORATOIRE D’ÉTUDES DE COMBUSTIBLES À BASE DE PLUTONIUM (Laboratory for studies of plutonium-based fuel), also known as the Bâtiment radiométallurgie (Radiometallurgy Building) or Bâtiment 52—shut down

This "building," for which the principal role was applied research on fast breeder reactor fuels, was actually composed of two sections, each in a separate building:

--Section 1 (RM1). RM1, put into operation in 1962, was designed for the most part for studies of plutonium-based fuel that had not been irradiated. The radioactive zone measured only 250 m3. RM1 has been completely cleaned up.

--Section 2 (RM2). RM2, which operated from 1968 to--depending on the source--1982, 1983, or 1984, studied irradiated plutonium-based fuel. It included a row of fourteen massive, shielded cells with walls in high-density concrete and leaded windows a meter thick. The cells totaled 18,000 m3 and the building as a whole 22,000 m3 [CEA DuF].

RM2 has been cleaned up once, but a more thorough cleanup is taking place during 2000 [DSIN 99]. According to a press release, the cells were pre-decontaminated and the walls thoroughly washed between 1990 and 1995; the remaining work is cutting up the cells walls and taking apart the piping for utilities, which has low-level contamination. Cleanup has produced the following waste: 510 t of low-level waste (Category A); 11 t of medium-activity waste (B); 10.5 m3 of radioactive effluents; and 1660 m3 of liquid with very low activity [CEAPR 99].

The CEA planned for RM2 to be ready to be removed from the list of INBs in 2001 [DSIN 00]. Dismantlingto level 3  is to begin in f2003 and end in 2008 [CEAD 99].  

The CEA operated numerous devices for the study of fusion at Fontenay, the first being TA 2000, inaugurated in 1957. The best known, however, was the Tokamak de Fontenay-aux-Roses (TFR), which went into service in 1968. In 1977 the Département de Recherches sur la Fusion Controlée occupied four buildings at Fontenay. Here was laid the groundwork for the JET (Joint European Torus) in the United Kingdom and for Tore Supra at Cadarache [CEA DuF].  Cadarache has since taken the place of Fontenay in the study of fusion.

The Sted was placed in service in 1965. High-activity effluents from the second generation INBs were sent to Marcoule for treatment. Low- and medium-activity effluents were treated in the station at Fontenay describe below. Afterwards they apparently were released into the sewers, as were the very-low-level effluents from Fontenay and, between 1962 and 1975 the very-low-level effluents from Saclay, brought to Fontenay for that purpose [CEAPr 99]. The Sted is composed of buildings 53, 07, and 10.

The Sted serves today for grouping, decontaminating, packaging, storing, and dispatching waste. Solid waste now stored at Fontenay and future wastes from dismantling, will be sent to Andra (category A and long-lived B); to Cadarache (long-lived B waste to wait for underground storage; very low-level waste to wait for Andra’s projected very-low-level dump); or to Centraco (wastes that can be incinerated or are metallic with low activity). Some very-low-level waste may be reused, as in metallic containers for the nuclear industry. Liquid wastes from washing and rinsing contaminated walls will be sent in shielded tank trucks to Marcoule, Cadarache or, if they can be incinerated, to Centraco. The press release that speaks of these liquid wastes does not mention other aqueous effluents [CEAPr].  DSIN states that aqueous effluents are sent to Saclay or Cadarache to be treated [DSIN 99].  

The station was put into operation in 1970, and the treatment of effluents of low and medium activity ended in mid-1994. The station was "declared to be in partial cessation of industrial activity" and is "undergoing cleanup for removal from the list of INBs and dismantling" [Andra 99].  Dismantling was to begin in 2001.

In 1967 the CEA installed an incinerator for the bodies of contaminated animals. It was renovated and put back into operation in 1994. During the 1990s it incineratd laboratory animals and hospital waste. We do not know if the incinerator is still operating in 2002.  

Since 1969 this installation has packaged irradiating alpha, beta, and gamma waste. Today it also stores contaminated solvents. Irradiating wastes are stored in the Station de stockage de décroissance (Storage station for decaying).

Put into operation in 1970, the station is composed of alveoles and shafts in a reinforced concrete trench. The wastes were to be stored there for no longer than five years [CEAD 93; Pomarola 70]. In 2000 the wastes included evaporator concentrates and drums of ashes, high-activity waste, and solid wastes contaminated with radium [Andra 00].  medium- and high-activity technological wastes. The CEA has begun to send the wastes to Cadarache. The CEA will send 78 m3 of medium-activity waste to Cadarache for storage in Cedra (if constructed) between 2000 and 2004.

INB 34 and 73 for the treatment and storage of radioactive effluents and wastes will remain operational to support the dismantling of RM2 and Building 18. They will be shut down and progressively dismantled from 2006 to 2010 [CEAPr 99].

According to the records of the CEA, releases of liquid effluents have always been below the levels authorized at the time. From 1989-1998, the release of 40,000 MBq of beta/gamma per year was authorized; 50 MBq were released; 1,000 MBq of alpha were authorized, 40 MBq released; 200,000 MBq of tritium were authorized, 2700 MBq released. This contrasts with the period 1958-1975 when the authorization was 888,000 MBq beta/gamma per year and 170,000 MBq were released; the authorization of alpha was 88,800 MBq and 4,100 MBq were released; and there was no authorization for tritium but 2,900,000 MBq were released.

Effluents leaving the site for Achères travel through special piping that is 400 mm in diameter and dedicated to them. In the vicinity of the site, radioactivity has been deposited on the walls of the piping. At the site exit it comes to between 0.05 and 0.2 Bq/cm2 of alpha and between 0.01 and 0.05 Bq/cm2 of beta/gamma. Daily analyses by the CEA indicate that there is no measurable transfer of contamination from the walls to the waste water (CEAPr 26.i.99].

The only contamination that the CEA has recorded in the water beneath the site is 20 to 60 Bq/l of tritium in the water, which circulates at a depth of 60 m. [CEAPr 26.i.99].

"The annual authorizations for gaseous effluents are 20 TBq for gaseous and 10 GBq for halogens and aerosols." According to the CEA, "the average annual releases before operation of building 18 came to an end amounted respectively to 3.4 TBq and 0.11 GBq." Since 1995, they were on average 0.03 TBq and 0.0004 GBq [CEAPr 26.i.99].

Cleanup and dismantling at Fontenay are particularly "delicate because the archives of the CEA’s first ten years, and even of experiences in 1960/75, are incomplete or very difficult to access." In order to fill in the gap in information and prepare for dismantling, the CEA began researching the site in 1996 and will complete its study in 2000.

Cleanup of contaminated points identified on site but outside the buildings began in 1996 and is to continue into 2002. According to the CEA, the "hot spots," which are the result of "incidents" have low or very low radioactivity.

There remain, however, some uncertainties, in particular in the soil that is underneath current installations and that therefore cannot be explored until the installations have been dismantled. It will be necessary to watch out particularly for residues, structures, and networks buried in the fill used for leveling the site during the initial dismantling" [Con viii.99].

Between 1999 and 2004 the sewers on site will be renovated. Two separate networks will be established: one for rain water and sanitary water, and the other for chemical and very-low-level radioactive liquids. The latter will be equipped with a treatment unit and large storage capacity, to retain effluents if an incident occurs [CEAPr 26.i.99].

The years 2008 to 2010 will be devoted to cleaning the land on which the dismantled buildings stood.

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