Status and perspectives for MOX fuel production in Russia

TABLE 1. HISTORY OF MOX FABRICATION IN RUSSIA

Manufacturing process	Manufacturing pilot	Reactor	No. of assemblies (mass of Pu)
Comilling (pellets)	Dimitrovgrad (1970)	BOR-60 (1973)	(a few tens of kg)
Pyrometallurgy	Dimitrovgrad (1970)	BOR-60 (1975)	(a few tens of kg)
Coprecipitation	PO Mayak (1980) Dimitrovgrad (1970)	BOR-60 (1980)	(10 kg)
Plasma chemistry	Moscow (1980)	BOR-60 (1981)	2 fuel pins (about 1 kg)
Comilling (pellets)	PO Mayak (1980)	BN-350 (1980)	10 fuel assemblies (about 80 kg)
Amonia coprecipitation (pellets)	PO Mayak (1980)	BN-350 (1992)	1 fuel assembly (about 10 kg)
Amonia coprecipitation (pellets)	PO Mayak (1980)	BN-600 (1992)	8 fuel assemblies (about 80 kg)
Comilling (pellets)	PO Mayak (1980)	BN-600 (1990)	12 fuel assemblies (about 100 kg)

Research on the use of plutonium in light-water reactors began only recently as a part of the plutonium disposition program and as a result of the lack of state financial support for fast reactor programs. No experiments have been carried out yet in industrial VVER-1000 reactors, although research is being conducted on the use of MOX in VVER-1000 reactors and aimed mainly at the use of MOX fuel in the new VVER-640 (or NP-500) reactors. A special testing facility has been established in order to generate experimental data and establish a design program for the use of MOX fuel. Research on fuel rod arrangement in uranium-plutonium fuel assemblies for VVER reactors is also proposed at this facility. A program to use MOX-only fuel assemblies in an existing reactor is being developed as well. Existing MOX fuel fabrication facilities Two pilot plants for MOX fuel fabrication exist in Russia: the Paket and Granat plants, both located at Mayak (Chelyabinsk-65). These two plants are designed to work with weapons-grade plutonium, and are designed to produce MOX fuel for fast reactors. Their capacity is not large-the maximum throughput of plutonium at the Granat plant is 50 kg per year (or one metric ton of MOX fuel) with a limited single loading of 300 g of plutonium. The capacity of the Paket plant is 100 kg of plutonium per year, or 30-36 fuel assemblies, which corresponds to one metric ton of MOX fuel with 20% plutonium content. The Paket plant was started up in 1980. At this facility, uranium and plutonium oxide powders, which have been produced separately, are mechanically mixed together. Next, a binding agent is added to the mixture, and everything is again mixed, granulated, and pressed into fuel pellets. Then the pellets are dried and sintered. After that, fuel pellets are tested, cladding is prepared, the pellets are placed into columns, the columns are placed into the cladding, and the rods are welded and tested. After decontamination, the rods are taken to the Elektrostal plant, where fuel assemblies are produced. Russian specialists believe that the Paket plant can also be used to fabricate experimental fuel rods from weapons plutonium for research thermal neutron reactors. The Granat facility, which began operating at the beginning of 1988, is devoted to fabrication of granulated MOX fuel for fast reactors, with plutonium from reprocessed fast reactor spent fuel or from weapons plutonium, with a plutonium concentration of up to 25%. The Granat facility has currently stopped operating for safety reasons. This facility consists of 14 glove boxes. The MOX fuel fabrication technology at Granat is based on co-precipitation of uranium and plutonium from nitric acid solutions. The resulting granules are very dry and generate almost no dust when handled. These granules are then taken to the Paket plant for fabrication into pellets and rods. Construction began in 1984 on the "Complex 300" plant, which is designed to prepare fuel rods for fast reactors. The capacity of the plant is 30 metric tons of MOX per year. Work on the plant was stopped in 1989 because of delays in the construction of BN-800 reactors. The plant is located in a four-story building which measures 300x54x20 meters with an overall floorspace of 64,000 m2. On the second floor there is a line of chambers designed to accomodate a production line to manufacture fuel rods from MOX granulate. A complete set of production equipment exists, but has not been installed. The MOX fuel fabrication technology at Complex 300 is the same as that used at that used at the Paket plant. However, because Complex 300 (unlike Paket) is also designed to work with reactor-grade plutonium, it is equipped with shielded boxes and manipulators. As a result of the halt in construction, the condition of the building and assembly equipment has deteriorated. On the whole, Russian experts are skeptical about continuing construction on this plant, since the technical solutions proposed in its design are much less sophisticated than those in design concepts for similar MOX fuel fabrication facilities in the West. It is unlikely that the Complex 300 plant could be used for fabrication of MOX fuel for thermal reactors using military plutonium, since it is designed to make fuel pellets for fast reactors which have a number of differences from pellets for thermal reactors. In addition, the assembly equipment is not designed to handle military plutonium. At the present time, Russia is working closely with Germany and France in order to develop a pilot MOX fuel production plant which would take advantage of Western experience and technology. Two designs are under consideration. The first is the "Tomox 1300" facility, specified in the joint French-Russian AIDA-MOX program to convert 1300 kg of weapons plutonium into MOX fuel annually. The total capacity of the facility would be 30 metric tons of MOX fuel per year. A joint German-Russain study proposes a pilot plant with capacity of one metric ton of weapons-grade plutonium per year, which corresponds to 10 metric tons of fuel for LWRs with a maximum plutonium content of 15%. These preliminary studies have been completed, and currently all three sides are carrying out negotiations on the location and financing for the plant. The estimated cost is about $130 million. Further study is needed to determine whether or not this pilot plant could also be used for fabrication of MOX fuel for fast neutron reactors with up to 45% plutonium content. Anatoli Diakov is a professor of physics at the Moscow Institute of Physics and Technology. In 1990 he established jointly with Professor Frank von Hippel the Center for Arms Control, Energy and Environmental Studies at the Moscow Institute of Physics and Technology. Dr. Diakov's current activities include work on the Russian policy for weapon grade plutonium disposition, transparency and irreversibility of nuclear arms reduction.