[en] Basic proposals on completing calculational procedures of sodium cooled reactors hydrogen safety justification, particularly steam generator (SG) box, are presented. It is pointed out that hydrogen appearance in SG box is possible only in accidents with multiple failures. The data presented shows that hydrogen safety and explosion-proofness of fast reactor facility SG box are provided without any special complex and expensive means

No abstract available

[en] The results of the analysis of the sate and prospects of developing NPPs with the fast neutrons reactors are presented. The basic trends of their development are considered. Comparison of the technical-economical indices of the power units with different coolants is given. Special attention is paid to developing the new generation of gas-cooled reactors, capable of increasing the safety levels and competitive efficiency as well as to solving the problem on the long-lived wastes storage

[en] The experience gained in the BN-350 plant is of fundamental importance with a view to sodium/water operation and separation in the steam generator by means of a simple wall. It was found that damage due to water ingress in the sodium loop can be prevented. Partitioned steam generators with a suitable protective system have certain advantages which enable localisation of the defect and also, if necessary, continued operation of the intact channels, independent of the extent of the original leak. (orig.)

[en] Design specific features of steam generators being a part of a NPP with the BN-350 type reactor are considered. The results of investigation of conditions for the steam generator reliable and safe operation are presented. The problems of steam generator maintenance and repair are discussed. Operational experience of the BN-350 type steam generator at different loadings and pressures has shown that they are convenient and simple in operation. Their characteristics correspond to calculational ones, automatic control systems assure the designed level of parameters. Accidents with water leakage in evaporators testify to the fact that in order to assure reliable operation of steam generator a thoroughful material and welded joints control is required in the process of manufacturing and assembly including tube production. The operational experience of the BN-350 type steam generators shows that even at considerable water leaks in sodium the emergency protection system can prevent the plant failure. It is concluded that the BN-350 type steam generators may be considered as one of possible variants when selecting construction of steam generators for prospective NPPs with sodium cooled fast breeder reactors

[en] Our national experience demonstrates reliable operation and high level of nuclear and radiational safety of fast reactors

[en] The main results of malfunction experimental studies connected with sodium-water interaction are presented. Considered are the main principles of calculational methods elaborated in order to analyze accidents in the steam generator and in the sodium circuit of an NPP with a fast reactor. Stated are the USSR modern approach to safety problems of the sodium-water steam generators with one-wall separation of coolants and demands to their emergency protective systems. It is shown that steam generators with sectioned design and appropriate procective system have some advantages; these designs allow one to localize consequences of an accident in a demaged area and to provide (if necessary) running of the steam generator using intact sections regardless of the initial volume of water flow into sodium

[en] Steps of the development of fast reactors in the world are analyzed. Achievements in the field of the elaboration and operation of sodium cooled fast reactors are performed. Means for the advancement of concurrent ability of this type of NPP units are discussed. State of works on types of gas, vapor, heavy metal cooled fast reactors briefly reviewed. Main problems in the realization of these directions of the development of fast reactors are posed

[en] The consideration is given to the problems and goals of the «Generation IV» International Forum, its structure, road map, basic characteristics, which is required to provide in the design of G-IV reactors. The main directions of works on reactor technologies of fast sodium reactor, fast lead reactor, fast gas reactor, supercritical water cooled reactor, molten salt reactor, supercritical water reactor are discussed

[en] A statistical model of a fuel element cluster considering the laws of channel flow section distribution obtained in experiments at the BN-600 reactor fuel assembly mock-up is suggested. Technique for calculating the fuel assembly temperature field based on the sequential calculation of a set of fuel assembly versions taking into account the interchannel heat and mass transfer is described. Variants of channel flow section distribution formed by fuel elements are realized using the Monte-Carlo method according to the given function of channel flow section probability density. As a result of the calculations statistical distributions of temperature increase in channels without account for the interchannel heat and mass transfer and with it are obtained. The effect of interchannel transfer on the reduction of maximum nonuniformity in coolant temperature increase caused by dispersion of channel flow sections is shown. The conclusion is made that if heat and mass transfer is not taken into account the value of coolant temperature increase in separate channels coincides with limited value obtained by the dispersion method