[en] Enrichment Technology is an innovative, high-tech company that develops, manufactures and installs gas centrifuges for enriching uranium. In addition, Enrichment Technology designs enrichment plants that use gas centrifuge technology. This technology offers the most efficient and cost-effective method for enriching uranium yet: high-performance, safe technology that dominates the market with a global share of 45 percent. A determining factor in Enrichment Technology's success is its mission: supplying its customers with safe, reliable technology. Production of the centrifuges requires versatile know-how and collaboration between different departments as well as interdisciplinary teams at the various sites. More than 2000 operators at 8 sites in 5 countries contribute their individual knowledge and personal skills in order to produce this exceptional technology. The head office is in Beaconsfield near London and the operational headquarters are in Almelo in the Netherlands. There are other sites in Germany (Juelich und Gronau), Great Britain (Capenhurst) as well as project sites in the USA and France. Capenhurst is where experienced engineers design new enrichment plants and organise their construction. Centrifuge components are manufactured in Almelo and Juelich, while the pipework needed to connect up the centrifuges is produced at the site in Gronau. In Juelich, highly qualified scientists in interdisciplinary teams are continuously researching ways of improving the current centrifuges. Communication between specialists in the fields of chemistry, physics and engineering forms the basis for the company's success and the key to extending this leading position in the global enrichment market. (orig.)

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[en] A study has been made of the feasibility of converting the 5-MW TR-2 reactor at CNAEM to use fuel with uranium enrichment of <20% (LEU) instead of its current 93% enriched (HEU) fuel. The criteria applied in judging the merits of the various LEU options used were: 1) fuel cycle costs must not be substantially increased relative to those with HEU fuel; 2) flux levels, or activation rates, at irradiation positions must not be reduced by more than 20% relative to those for the HEU core; and 3) adequate safety margins must be maintained. The study concentrated on LEU fuel design using U³O⁸-Al fuel meat with a uranium density in the range 2.3 to 3.0 g/cm₃ in the fuel meat with meat thickness varying between 0.9 and 1.00 mm, the number of plates in the LEU element being reduced from 23 in the HEU element to 19 to 20 to maintain adequate cooling. Fuels within this density range are expected to be commercially available within the next two years. From the results of the study it appears to be feasible to safely operate the TR-2 reactor using LEU fuel without increased fuel cycle costs or decreased performance using U²O⁸ fuels with densities in the 2.3 to 3.0 gU/cm₃ range. (author)

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[en] The disposition of surplus nuclear materials has become one of the most pressing issues of our time. Numerous agencies have invoked programs with the purpose of removing such materials from various international venues and disposing these materials in a manner that achieves non-proliferability. This paper describes the Nuclear Fuel Services, Inc (NFS) Nuclear Material Disposition Program, which to date has focused on a variety of Special Nuclear Material (SNM), in particular uranium of various enrichments. The major components of this program are discussed, with emphasis on recycle and return of material to the nuclear fuel cycle. (authors)

No abstract available

[en] Historically space reactors flown or designed for the U.S. and Russia used Highly Enriched Uranium (HEU) for fuel. HEU almost always produces a small and lighter reactor. Since mass increases launch costs or decreases science payloads, HEU was the natural choice. However in today's environment, the proliferation of HEU has become a major concern for the U.S. government and hence a policy issue. In addition, launch costs are being reduced as the space community moves toward commercial launch vehicles. HEU also carries a heavy security cost to process, test, transport and launch. Together these issues have called for a re-investigation into space reactors the use Low Enriched Uranium (LEU) fuel.

[en] In research reactors, highly enriched uranium (HEU) is used as fuel for their purposes of operation. However, the United States strongly required in 1977 that these HEU should be replaced by low enrichment uranium (LEU) of 20% or less, or even in unavoidable cases, it should be replaced by medium enrichment uranium (MEU). INFCE (International Nuclear Fuel Cycle Evaluation) which started its activity just at that time decided to discuss this problem in the research reactor group of No. 8 sectional committee. Japan has been able to forward the work, taking a leading part in the international opinion because she has taken the countermeasures quickly. INFCE investigated the problem along the lines of policy that the possibility of reducing the degree of enrichment should be limited to the degree in which the core structures and equipments of research reactors will be modified as little as possible, and the change of fuel element geometry will be done within the permissible thermohydrodynamic capacity, and concluded that it might be possible in near future to reduce the degree of enrichment to about 45% MEU, while the reduction to 20% LEU might require considerable research, development and verification. On the other hand, the joint researches by Kyoto University and ANL (Argonne National Laboratory) and by Japan Atomic Energy Research Institute and ANL are being continued. IAEA has edited the guidebook (IAEA-TECDOC-233) for reducing the degree of enrichment for developing countries. (Wakatsuki, Y.)

[en] A new concept of High Flux Reactor with Solid Coolant (HFRSC) is presented. Due to application of high temperature moving fuel with significant heat capacity, used to accumulate energy generated in the reactor core, it is possible to overcome technological and physical barriers limiting the values of neutron fluxes in case of traditional reactor design. For HFRSC MEU or LEU is a natural choice to ensure essential temperature coefficient of reactivity. Application of water in the reactor core only as a moderator creates an opportunity to avoid pressurized circuit and place reactor into pool with all the advantages both for reactor safety and easy access to experimental facilities. A comparison with traditional high flux research reactor concept (ANS) is presented. (author)

[en] In the last decade research reactor operators have focused mainly on the issues of disposal of spent research reactor fuel and the development of high density fuels. The safe supply of fresh uranium did not receive as much attention. This is surprising since the United States - who was the main supplier for LEU and HEU since the late 1950's - stopped supplying non-US research reactors with enriched uranium a decade ago. The reason for this stop of supply is described in this paper. This paper explains how research reactors in the E U continued to operate during the last decade, in spite of the fact that their primary supply source had not provided LEU and HEU over the same period. (author)