The recent Russian results on technetium transmutation into ruthenium are summarized, including the first isolation of artificial stable ruthenium from irradiated technetium targets. To cite this article: V.

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99TC is one of the most long-lived fission products (T1/2 = 2.14.105 yr) and has a considerable yield in the fission of nuclear fuel by neutrons ( -6 mass %). Its content is -I kg/ton in spent thermal-reactor fuel and may be 2-3 times greater in fast-reactor fuel. On the basis of the total electrical-energy production in reactors around the world, which was 252 GW-hr in 1994 [1], the accumulation of 99Tc may be -7.5 ton/yr. Despite many years of searching for applications of technetium, the total world demand for this nuclide currently is no more than a few hundred grams per year, principally for scientific research. Therefore, some non-Russian programs and Russian concepts for the treatment of radioactive wastes provide for the isolation of this radionuclide in a separate fraction and its storage until methods for rendering it harmless have been developed [2][3][4][5].A radical approach to the 99Tc problem calls for its transmutation; in non-Russian waste-treatment programs, combustion of this nuclide and some other fission products with actinides is envisaged. The rational for this is that the 99Tc nucleus has a high capture cross section for thermal and intermediate neutrons and the transmutation products formed are of low radioactivity. It has now been proven that, in principle, the combustion of 99Tc may be conducted in various reactors: in light-and heavy-water power reactors, in fast reactors, and in special transmutational reactors currently under development and also in neutron-generating linear accelerators [6][7][8][9][10][11]. However, there has been virtually no consideration of the practical application of the transmutation products of 99Tc --principally ruthenium, which belongs to the platinoid subgroup.Ruthenium, which costs $t0/g [12], is mainly used in the electrical-engineering and electronics industries. The world demand for this element is 7.4 ton/yr, with reserves of around 3100 ton [13] and could be completely satisfied by the transmutation of the 99Tc stored at power reactors. The extensive research on the development of methods of isolating platinoid metals from spent reactor fuel in various countries has led to limited success [13], and consequently the transmutation of 99Tc is not currently regarded as an industrially significant method of obtaining platinoid metals.In the present work, we consider the irradiation and processing of a technetium target to obtain ruthenium that is suitable for practical use.

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