Apart from the calculated quantity of uranium and plutonium mixed with the waste, there is always in a reprocessing factory a difference between the measured quantity that enters and the measured quantity that goes out-the definitive discrepancy (“écart”).

Since 1977 all the plutonium at La Hague is transformed into PuO2. The PuO2 is packaged in stainless steel boxes, on the order of 3 kg per box. Four to five of these boxes are put in soldered cases and the cases placed in tight containers and the containers stored in BSI (UP3) and in BST1 (UP2-400, but used by UP2-800) [Cogéma 92b].

Prolonged storage of separated plutonium reduces its energy value by decreasing its content in fissile isotopes and increases the problems of radioprotection during its manipulation. The plutonium 241 decays with a half-life of 14 years, giving americium 241, which decays with a period of 458 years by alpha disintegration into neptunium 237. Americium 241 is a very powerful gamma emitter; neptunium 237 is an alpha emitter with a period of 2 million years. A separation of americium 241 from plutonium is possible, but creates new wastes (see Valduc) and is expensive (between 50 and 75 francs per gram of plutonium) [Bemdem 90].

Uranium in the form of a solution of uranyl nitrate, ordinarily at 400 g/l, is stored in the MAU workshop in UP2-400 and in the T5 workshop in UP3, which can hold up to 1260 t of uranium.

Contracts with foreign clients for reprocessing at UP3 provided for storage of the plutonium produced by Cogéma without charge for a period of two months. If the client wanted long-term storage of the plutonium, it needed to let Cogéma know at least four months in advance and pay for the storage. For the uranyl nitrate, the UP3 contracts provided for free storage for up to three months. If the utility wanted longer storage, it had to notify Cogéma at least three years in advance [Wise 94a].

II.B. Atmospheric Effluents

Radioactive atmospheric effluents come from the dissolution of irradiated fuel, from the calcination of high level liquids during vitrification, from the air released by aeration installations, and possibly also from evaporation units. They are released into the environment after partial decontamination in the workshops where they are produced.

Since 2007, La Hague has been authorized to release each year the following radioactive gaseous effluents or aerosols: 150 TBq of tritium, 0.018 TBq of radioactive iodine, 470,000 TBq of radioactive rare gases including krypton, 28 TBq of carbon 14, 0.001 TBq of other artificial beta and gamma emitters, and 0.000,01 TBq of artificial alpha emitters [JO 10.i.07].  A decree of 27 February 1984, had authorized the release each year of 2,200,000 GBq of tritium, 480,000,000 GBq of krypton 85, 110 GBq of halogens, and 74 GBq of aerosols. A major revision, including introduction of a limit on carbon 14, was made in 2003 and small changes in 2007.  In 2003 for the first time limits were set on releases into the air of chemical substances.  

The radioisotopes that contribute the highest radioactivity to the gaseous effluents are:

--tritium. Less than 1% of the tritium in the irradiated fuel passes into the dissolution gas (about 50% remains trapped in the hulls; the remainder in the form of water in the acid dissolving solution);

--krypton 85. The krypton 85 in the irradiated fuel passes entirely into the gaseous effluents;

--carbon 14   

--iodine 129. The iodine-129 is released from the irradiated fuel in quasi-totality, but only a small portion is found in the dissolution gas;

--aerosols, including fine particles of uranium and plutonium.

The tritium and the krypton 85 that pass into the gaseous effluents are released in their entirety.  According to Areva, more than 96% of the gaseous iodine is absorbed by sodic solutions, which are then diluted in tritiated water. The carbon 14 is absorbed in part by solutions containing soda, which are also diluted in tritiated water. The major part of the remaining gaseous iodine is trapped in filters designed for this element [ArevaSnrLH 08, p. 38].  A filtration system having an efficiency described by Areva as 99.9% is designed to trap aerosols.

Releases of radioactive gaseous effluents in 2008 as reported by Areva were 46.4 TBq of tritium; 0.00714 TBq of radioactive iodine; 155,000 TBq of rare gases, in particular krypton 85; 13.5 TBq of carbon 14; 0.0001 TBq of other beta and gamma emitters, and 0.0000018 TBq of alpha emitters [ArevaSnrLH 08].

II.C. Liquid effluents

--THE ORGANIC SOLVENTS. In the late 1990s the treatment generated a decontaminated dilutant and a decontaminated solvent of concentrated TBP, which were reused, and a solution (about 1% of the original solvent) that contains almost all the radioactivity. Areva states the process has been changed and that in 2008 little organic solvent was produced.  Nevertheless, solvent is still being treated in the Atelier MDS (Solvent mineralization plant), which began operating in 1998 near the STE-3 spent solvent-storage building.

In MDS spent TBP, mixed with up to 40% used oil or diluent, is mixed with magnesium lime water and fed into a pyrolysis reacter where heat causes the water and diluent to evaporate and the TBP to react with magnesium hydroxide. This process splits the feed into a gaseous stream (butene, butanol, dodecane vapors, nitrogen, steam) and ashes (a mixture of magnesium oxide and phosphates). The ashes are mixed with concrete, grouted, and packed in drums for dispatch to Andra for shallow land disposal. The gases are filtered to separate out a fine dust of magnesium phosphates and magnesia. The radioactivity stays with the dusts. The vapors are incinerated and the off gases from incineration are scrubbed, filtered, and released through a stack. Our source does not state what happens to the dusts. The design throughput of MDS is 3 kg of TBP/hr [Moulin 98].  

Solvents regarded as "very weakly" or "weakly" contaminated may be sent to Socodei's Centraco plant at Marcoule for incineration.  The ashes from the incineration are packaged in cement and placed in metal casks for dispatch to Soulaines [Socodei 07; ArevaSnrLH 08].

--THE VERY HIGHLY RADIOACTIVE ACID SOLUTION containing fission products and transuranic elements. It is concentrated by evaporation, stored for a year in order to reduce the radioactivity, and then vitrified with other substances in the R7 and T7 workshops.

Cogéma vitrified the liquid stock of fission products coming from light water fuel reprocessed in UP2 and UP2-400 that was awaiting vitrification when R7 was put into service. Corrosive liquid waste from the uranium-molybdenum fuel used in early gas-graphite reactors remains to be vitrified [NucF 3.xi.08]. .Today solutions are vitrified as they are produced.

Vitrified wastes are poured into stainless steel containers, each holding 150 l. Each workshop can treat 60 l/h of wastes and produce 600 containers or (240 t or 90 m3 of glass) per year. R7 can store 4,500 containers and T7, 3600 containers. E-EV-SE, a modular extension of T7, can store 4000 containers without increasing its present capacity. NPH also stores vitrified waste.  Areva plans to construct an extension of E-EV-SE for 2012 [NucF 3.xi.08]. The new hall will have space for 4212 containers, which will be added to what Areva states is existing space for 12,500 containers. Construction began in October 2009 [ArevaPress 22.viii.09].

At the end of 2007, a total of 9088 containers representing a volume of 1488 m3 of vitrified waste were stored at La Hague [Andra 09].  In 2008, 793 containers of vitrified waste were produced, and at the end of the year 9541 such containers were stored at La Hague (some having been sent abroad) [ArevaSnrLH 08].   

The vitrified wastes include, according to Cogéma, 99% of the radioactivity of the irradiated fuel but represent about 3.5% of their mass [Cogéma 92b]. Because of the concentration of the radioactivity, a lethal dose would be received at one meter in less than one minute. The strong thermal emission of these wastes necessitates intermediate storage of at least thirty years before definitive storage [Wise 97].

--ACID EFFLUENTS OF MEDIUM AND LOW RADIOACTIVITY. The majority are treated and then reused or vitrified according to their level of radioactivity.

--BASIC SOLUTIONS. They are evaporated and the concentrates vitrified with the other very high activity wastes.

--OTHER AQUEOUS EFFLUENTS. These effluents come from the treatment of gaseous effluents, fuel storage pools, various cleaning operations, and laboratories.

Before STE3 entered into service, STE1 and STE2 treated effluents from UP2, mainly by co-precipitation. The sludge produced in STE2 was stored in bulk in six tanks located in STE2. According to Andra these tanks still contained 9077 m3 of sludge, representing 0.12EBq at the end of 2007 [AndraInv 09]. (An experiment in conditioning the sludge in bitumen had produced 340 barrels of waste).

Starting in about 1989, STE3-T treated the majority of the effluents coming from UP2 and UP3, likewise by coprecipitation. STE3-B coated the sludge from this treatment in bitumen. The sludge is stored in containers in STE-B and an extension of STE3, D/E-EB. Each installation can store 20,000 drums. As of the end of  2007,  STE3 contained 10,572 drums, representing 10.55PBq, largely of beta radiation [AndraInv 09].

Cogéma planned to shut down the units for coprecipitation and bitumen packaging at the end of 1995 [Bonnet 95]. These units continue to operate, but handle a reduced quantity of effluent. By 2008, under normal conditions of operation, almost no asphalted wastes were produced [ArevaSnrLH 08, p. 55].  To decrease its reliance on them, Cogma/Areva sorts effluents more selectively and has added new evaporation units. Instead of treating all effluents by floculation and decantation to produce sludge containing the majority of the activity and then incorporating this sludge in bitumen, Cogéma/Areva treats much of the effluent by evaporation, producing concentrates also containing the majority of the radioactivity and then incorporating these concentrates in glass.

After treatment, liquid effluents are filtered and monitored and released into the English Channel by means of a pipe, the end of which is located in the Raz Blanchard current.  The pipe travels under ground on land for 2500 meters and in the sea for 5000 additional meters [ArevaSnrLH 08]. An old discharge pipe no longer in use was dismantled in 2001-2003.

As of 2007, La Hague is authorized to release each year in liquid effluents18,500 TBq of tritium, 2.6 TBq of iodine, 42 TBq of carbon 14, 11 TBq of strontium 90, 8 TBq of cesium 137,  0.5 TBq of cesium 134, 15 TBq of ruthenium 106, 1.4 TBq of cobalt 60, 60 TBq of other beta and gamma emitters, and 0.14 TBq of alpha emitters [JO 10.i.07].  A decree of 28 March 1984 had authorized 37,000,000 GBq of tritium, 220,000 GBq of strontium 90 and of cesium 137, 1700 GBq of alpha emitters, and 1,700,000 GBq of beta/gamma emitters other than tritium per year. As with the gaseous effluents, the 1984 authorization was substantially revised in 2003 and slightly modified in 2007.  

In 2003 releases of chemical effluents were made subject to limitations for the first time.  These effluents contain chemical compounds and elements in solution (acids or bases, salts, metals, organic products).  More than twenty of them must now be reported to ASN.  Those released in the greatest quantity, according to figures from Areva, are nitrates (2,390 t in 2008) and nitrites (less than or equal to 34 t in 2008) [ArevaSnrLH 08].

Liquid effluents are classified as "V" if beta activity apart from tritium is less than 1.85 MBq per liter and if alpha is less than 3.7 kBq per liter.  Other radioactive effluent is classified as "A."  In 2008 La Hague released into the sea 1607 m3 of "A" effluent and 98,928 m3 of "V" effluent.  It also released through the pipe 574,850 m3 of water from various rain water networks and underground drainage networks [ArevaSnrLH 08].

Releases of radioactive liquids into the sea in 2008, as reported by Areva, contained 8,190 TBq of tritium; 1.06 TBq of  iodine; 6.24 TBq of carbon 14; 0.17 TBq of strontium 90; 1.0 TBq of  cesium 137; 0.075 TBq of cesium 134; 3.37 TBq of ruthenium 106; 0.12 TBq of cobalt 60; 4.18 TBq of other beta and gamma emitters;  and 0.020 TBq of alpha emitters [ArevaSnrLH 08].  

II.D. Solid Wastes

Andra, the national radioactive waste agency, reports that from its creation through the end of 2007 the La Hague site produced the following total volumes of waste in equivalent cubic meters when packaged:

High activity  1650 m3

Intermediate activity--long lived   19,171 m3

Low activity-long lived         4,952 m3

Low and intermediate activity- short lived      156, 213 m3

Very low activity                 17,113 m3.

These wastes include the solid products resulting from treating gaseous and liquid effluents, as described above and the categories of solid waste described below [AndraSyn 09].   

-CLADDING AND HULLS.

The cladding and cartridges (magnesium and graphite) from UNGG fuel are stored in bulk under water in silos in the north-west zone of the site. As of  2008  silos 115 and 130 contained a total of 1055 t of magnesium, graphite and metal [ArevaSNR LH 08], which Andra described in 2000 as  representing 24 TBq of alpha and 2.2 PBq of beta/gamma activity [Andra 00]. 

The hulls and end pieces from PWR fuel reprocessed in UP2/HAO were stored in bulk under water in a silo near the HAO installation and, since 1988, in closed containers arranged in old storage pools for irradiated fuel [MinIn 90, Andra 96]. In 1999 HAO, S1, S2, and S3 stored 2245.4 t of wastes [Andra 00]. 

The hulls and end pieces coming from PWR fuel reprocessed in UP3 and UP2-800 were cemented and then stored in the installations EDS and the extension D/E-EDS. This procedure stopped in 1995 and was replaced by storage in water while awaiting the startup of the Atelier de compactage des coques (Hulls compaction workshop, ACC).  At the end of 2007, 1518 casks of cemented hulls and end pieces were stored at La Hague.  Their radioactivity totaled 0.35 EBq, largely from activation products [Andra Inv. 09].  ACC, which started operation at the end of 2001, compacts hulls, end pieces, and technological waste that necessitates deep underground disposal. The compacted waste is in the form of disks and is stored in CSD-C canisters (universal canisters) identical in shape and size to canisters for vitrified waste. According to one source, most of the technological waste compacted was to come from the La Hague plant; some from the Melox plant [Chotin 98]. Building ECC stores packages produced by ACC.  DSIN authorized the storage in a pool at UP2-400 of 700 liters of hulls from Mox and UO2 fuel previously stored in the Atelier pilote de Marcoule [DSIN 99]. It seems likely that those hulls were destined for compaction in ACC.  As of the end of 2007, 6089 containers of compacted hulls and end pieces were stored at La Hague.  They have 818 PBq of beta activity [AndraInv 09].

--FINES from shearing and dissolution fines. Today they are vitrified with the solution of fission products. In the past they were stored with the cladding and the hulls.

--WASTES IN BITUMEN. See “other aqueous effluents” above. These wastes present an alpha activity of 3.7GBq/t and cannot be sent to Andra [Pradel 95].

--TECHNOLOGICAL WASTES. The wastes are decontaminated when necessary, preconditioned in standard 120-liter barrels, then conditioned by cementing or compacting [ArevaSNR LH 09, p. 53].  Since 1990, the AD2 workshop has grouped and packaged technological wastes from UP2 and UP3.   Most of the cemented technological wastes can go to a site belonging to Andra [Pradel 95]. Wastes that are irradiating or are too contaminated with alpha emitters to be sent to Andra are stored at La Hague in AD2 and EDS. The R1 and T1 workshops can also package and store technological wastes. The compaction workshop which treats hulls and end pieces was, in addition, to treat technological wastes from Zone 4, the process zone [Ledermann 96].

--RESINS. Resins are used to clean the water in storage pools.  As of the end of 2007, 332 m3 of two categories of resins and 51 t of two other categories were stored at La Hague awaiting conditioning [AndraInv 09, p. 54].  The radioactivity of the resins is chiefly due to cobalt 60. ACR (Atelier de Conditionnement des Résines) packages bead and crushed resins. The resins are concentrated by natural settling; pretreated with calcium to prevent them from reacting with cement; mixed with cement; and poured into metal drums, which are stored in shielded casks ready for “near-surface disposal.” ACR was to have a nominal capacity of 200 400-liter drums per year and a maximum capacity of 300 drums per year [Guerrand 98; ArevaSnrLH 08].

--OTHER WASTES. Among the other wastes at La Hague reported in 2009 are concretions from cleaning the discharge pipe (45 m3) [AndraInv 09] and 6538 drums of alpha-contaminated technological waste shipped to the installation from MOX fabrication plants and stored in Building 119 [ArevaSNR LH 08]

Special Problems Involving Legacy Waste

The majority of the waste from UP2-400 was stored without packaging. DSIN asked Cogéma to produce a plan for packaging the waste stored in bulk at the site and submitted the resulting plan to the Groupes permanents chargés des usines et des déchets (Permanent groups responsible for plants and wastes). Following the response of the Groups, DSIN, 27 January 1999, wrote a letter to Cogéma stating that recovery and packing of bulk waste in tanks at STE2, in silo 130, and in the HAO silo required priority action. The letter also asked Cogéma to make firm commitments on the retrieval and packaging of all other waste generated during reprocessing at UP2-400. Within a year of the letter Cogéma was to present a timetable for these activities; Cogéma was also to make an annual report on its progress in regard to the UP2-400 wastes. 

In 1999 DSIN credited Cogéma with the recovery of all the wastes in the trenches in the northwest corner of the site and with the repackaging of about 8000 m3 of waste from these trenches.  Despite the new requirements established that year, little further progress with the legacy waste has been made.  Following a study by the Groupes permanents d'experts pour les laboratoires et usines et pour les déchets  (Permanent groups responsible for laboratories, factories, and wastes) in November 2005, ASN confirmed the necessity of undertaking as rapidly as possible the retrieval of wastes in STE 2, silo 130, and the HAO silo.  In addition, Areva was asked to assign priority to alpha waste stored in Building 119.

In 2002 Cogéma promised to begin incorporating the sludge at STE 2 in bitumen.  However, on the basis of two experimental campaigns, ASN in September 2008 forbad further asphalting of the sludge in the facilities of STE 3.  Areva is studying, as alternative methods, cementing the waste or drying it through the DRY-PAC process.  ASN has specified that retrieval of the waste must be complete by the end of 2010 at the latest [ASN 08].

Silo 130 is a buried blockhouse, consisting of two 3000 m3 trenches, only one of which contains waste.  The waste, which consists of cladding and end pieces from UNGG fuel, technological waste, and rubble, is stored under water.  Areva plans to transfer the UNGG waste to the D/E EDS storage facility; remove the water from the silo and treat it in STE 3; then remove the waste and rubble from the bottom of the silo.  However, it is talking about the need to shore up the building first [ASN 08].

The HAO Silo is a buried basin [AndraSyn 09] containing cladding and end pieces form light water fuel cut up in HAO, plus fines, resins, and technological waste resulting from the operation of HAO.  The retrieval of the waste is made difficult by its heterogeneity and difficulty of access.  Dismantling the silo will require first dismantling equipment now on the silo's slab, building a retrieval cell, and qualifying the equipment that will be used.  In 2008 Areva told ASN that it was beginning new studies of how to proceed [ASN 08].  The decree authorizing the definitive shutdown and dismantling of HAO states that all waste must be removed from the silo by the end of 2022 [JO 4.viii.09].

Areva has been gradually decontaminating and cementing the alpha-contaminated technological waste from MOX production, housed in Building 119.  In 2008 UCD and AD2 processed 511 barrels [ArevaSnrLH 08].  The work will apparently be speeded up by devoting the workshop D/E EB of STE 3 entirely to this waste, which comes from abroad as well as from France [ASN 08].