[en] During the last year after the 16-th International Conference on Reducing Fuel Enrichment in Research Reactors held in October, 1993 in Oarai, Japan, the conclusive stage of the Program on reducing fuel enrichment (to 20% in U-235) in research reactors was finally made up in Russia. The Program was started late in 70th and the first stage of the Program was completed by 1986 which allowed to reduce fuel enrichment from 80-90% to 36%. The completion of the Program current stage, which is counted for 5-6 years, will exclude the use of the fuel enriched by more than 20% from RF to other countries such as: Poland, Czeck Republick, Hungary, Roumania, Bulgaria, Libya, Viet-Nam, North Korea, Egypt, Latvia, Ukraine, Uzbekistan and Kazakhstan. In 1994 the Program, approved by RF Minatom authorities, has received the status of an inter-branch program since it was admitted by the RF Ministry for Science and Technical Policy. The Head of RF Minatom central administrative division N.I.Ermakov was nominated as the Head of the Russian Program, V.G.Aden, RDIPE Deputy Director, was nominated as the scientific leader. The Program was submitted to the Commission for Scientific, Technical and Economical Cooperation between USA and Russia headed by Vice-President A. Gore and Prime Minister V. Chemomyrdin and was given support also

No abstract available

No abstract available

No abstract available

[en] The main results of work performed as part of a program to decrease the enrichment of fuel in research reactors and prospects for the future are present. The goals, the main stages of the program, and the degree to which they have been completed are described. The results of laboratory, design, technological work, and reactor and post-reactors tests on new fuel elements and fuel assemblies are presented. It is shown that the existing scientific and technological results are the basis for performing development work on a new generation of fuel elements for existing and future designs of research reactors

[en] The results of in-pile tests of fuel assemblies with 36% enrichment are presented. The report contents the information about the results of fuel assembly IVV-2M type in-pile tests for the safe operation limits discovering in power ramp and loss of flow operation regimes. (author)

[en] This report describes research reactors in Russia and built abroad on Russian projects, and main features of the Russian programme of reducing fuel enrichment in research reactors. (author)

[en] The report presents the main results of works under the Russian RERTR Program carried out in the last year and plans for 1998. Works under the Russian RERTR Program proceeded during the last year after the 19th International Meeting on RERTR held in Seoul. It is known that the Russian Program stipulates three principle stages of the works. Stage 1 includes development of fuel elements and fuel assemblies of VVR-M2, IRT and MR types with higher density fuel uranium dioxide. Stage 2 is concerned with development of high-density fuel (U₃Si₂, U₃Si, U₆Fe, UZr and others). Stage 3 involves development of fuel elements and fuel assemblies of VVR-MS IRT and IVV-10 types with high-density fuel. (author)

[en] The data about the phase and structural state of (U,Mo)Al_x layer have been scarce so far, thereby precluding from development of the measures for reducing the rate of layer growing. This paper presents the results of the structure study on the dispersed uranium-molybdenum fuel after irradiation to different burn up levels from 33 to 97% and one-hour annealings within temperatures of 150 to 580 Celsius degrees by the neutron diffraction method. The following conclusions have been drawn, -) the percentage of γ-U-9%Mo phase depends only slightly on burnup; -) the percentage of UAl₃ crystal phase does not exceed 0.5% and is almost constant in the range of burnups from 33% to 97%; -) the percentage of the Mo₉₀U₁₀ phase is constant and equals to about 1.5% and hardly depends on burnup; -) the percentage of amorphous phase such as (U,Mo)Al_x depends on irradiation parameters and increases as fuel burnup rises; -) annealing in temperatures above 300-350 C degrees results in crystallization of the amorphous phase with formation of the UAl₃ intermetallic phase

No abstract available