No abstract available

No abstract available

[en] Consideration is given to the state of problem on development of electronuclear reactor, based on 1GeV proton accelerator as alternative version of a facility for nuclear fuel freeding. Peculiarities of fuel production by electronuclear method are presented. Nuclear physical data provisions for engineering development of a target are discussed. The direction of electron nuclear reactor development on the basis of fuel element technology for fast reactor with metal fuel and sodium coolant is suggested. Results of modeling calcultions on such reactor efficiency in two modes: as a converter and as a breeder are presented. The first one utilizes the waste uranium in open fuel cycle, the second one uses it in closed cycle with plutonium addition. It is shown that electronuclear reactor has lower efficiency in electric power production, as compared with fast reactors. However, the electronuclear reactor produces almost 5 times as much of Pu per a unit of registered capacity. For electronuclear reactor there are no problems of nuclear safety which play an important role for fast reactors: electronuclear reactor is always subcritical

[en] This report discusses the practical approach to thorium utilization which might be effective to solve principle energy problems. Until now, the basic obstacle for a thorium fuel cycle was a need for a closed system. The technical advantages of a molten salt system are described

[en] The calculation of material buckling in a cold critical assembly is considered in detail. The technique is extremely simple, permitting rapid calculation without computers. Long intricate calculations, involving many minor effects that are difficult to assess, are not always justified, if only because of lack of accuracy in the physical constants. If certain effects become significant they can always be individually computed. It is admittedly not easy to decide which effects must be considered and which can be ignored. Hence, the importance we attach to the theoretical study of effects which are difficult to assess, aiming at simple, easily-understood formulae for their calculation which will clearly reflect their physical characteristics. 14 refs, 7 tabs

[en] The analogy between the Schroedinger stationary equation, describing the electron motion in the external field, and the single-group equation, describing in the diffusion approximation the neutrons flux in a nuclear reactor, is noted. The original approach is proposed on the basis of this analogy for numerical solution of the Schroedinger equation with application of a number of standard approaches for the equation solution, including the source iteration method and probably in the future the Monte-Carlo method, widely applied in the reactor calculation practice

[en] The progress in the field of designing and constructing a heavy-current proton linear accelerator became noticeable last year and allows one to count on large-scale industrial linac application. Symbiosis of linac and subcritical reactor as target has new opportunities for energetics. This accelerator concept is described

[en] Nuclear fission is the only reaction leading to actinide transmutation. In an accelerator based assembly, employing heavy water solution circulation actinides are almost permanently exposed to a high neutron flux. The actinide supply from the spent fuel elements of nuclear plants is balanced with removing fission products from the transmutation system. In the process of incineration in the hybrid water assembly there occurs a state when actinide concentrations do not change in time. It is in a steady state that the likely regimes of irradiation and transmutation performance of the system are studied. The fissions of the short-lived nuclide ²³⁸Np dominate in high level neutron fluxes, while in routine level fluxes it is the fissions of ²³⁹Pu that are dominant. It i shown that the transmutation performance depends on an acceptable energy deposition density rather than the type of the loaded actinide waste. (author) 13 figs., 3 tab., 5 refs

[en] The evaluation is made of consumption of the natural uranium necessary for performing several measurements on ''pure'' critical assemblies in order to obtain a set of evaluated constants for the calculation of heavy-water systems. The least informative ''measurements'' have been removed from a large set of model critical ''experiments''. The informativeness has been determined by the variation of the evaluation error, i.e., joint consideration of the microexperiments and macroexperimets. The calculations are performed anew at each new ejection step. The attained economy of the materials is approximately five times that in case of ''intuitive planning'' at an insignificant loss of accuracy. The conclusion is drawn to the effect that instead of a great number of experiments just a few critical measurements (three critical experiments per uranium lump with two various diameters at various lattice pitches) should be performed, provided they are performed and the results, processed as thoroughly as possible

[en] Results of the solution of neutron slowing-down and absorption problems in heterogeneous cells of nuclear reactors by an electronic computer have been analyzed. A blocked part of U²³⁸ effective resonance integral and its temperature dependence have been determined. The calculations have been performed in the one-level approximation. It is suggested that levels don't interfere. About 70 resolved resonance transitions are taken account of. The calculations have been carried out for three values of radii of natural metal uranium block: 0.5; 1.4; 2.6 cm at three uranium temperatures: 293, 500, 800 K. It is concluded that accuracy of the calculations based on the level parameters knowledge turns out to be higher than accuracy of integral measurements