[en] The basic advantages of neutrino method for the remote control and diagnostics of the main physical-power parameters of an active zone of reactor, namely dynamics of changes of the average estimations are considered: - level of capacity and energy-output; - nuclear density of each of a component of nuclear fuel isotope composition and according to a mix of actinides fission products; - one-group integrated density of neutron flow

[en] The article adduces results of the optimum control periodicity account for the system of the reactor emergency cooling by high pressure pumps. Authors showed the control periodicity can be increased in several times with respect to regulations control periodicity

[en] The operating radiation monitoring systems (AKRB-03) for WWER-1000 units of Zaporozhskaya NPP was considered. Theirs main disagreements with the requirements of regulatory documents are pointed out

[en] The opportunity of a deferential approach at loading of dry storage systems with spent fuel is investigated based on the saved defects and changed geometry TBC while in service. The list and parameters of the data for the three-dimensional calculative analysis of cladding's thermal-creep by dry storage condition is determined

[en] The author describes the design concept, mechanism, system structure of the signal system and its utilization in reactor

[en] The development of power engineering in the 21 century will be governed by the tendency to a more uniform consumption per capita and by regions. The principally positive characteristics of nuclear energy - unlimited fuel resources, its high power capacity, ecological compatibility with the possibility of high concentration of wastes predetermine the development of a large-scale nuclear power engineering among the completing energy sources. The economical efficiency of nuclear engineering, its safety, sufficient characteristics for nuclear fuel reproduction and safeguards for the fission materials nonproliferation are the conditions for development of such a nuclear power engineering. The acceptable safety level is closely connected with the scale of power engineering and the areas of the nuclear energy sources application. However the progress in the direction of decreasing the potential danger of reactor facilities and lowering the price of protection systems is possible

[en] New results of the separate-effect tests on hydrogen absorption by Zircaloy and experiments on ZrO₂ shell failure are described. Description of the test conduct and main results obtained in the bundle experiments QUENCH-03 and QUENCH-04 is given. (orig.)

[en] The requirement of ultra high reliability of the safety critical software can not be demonstrated by testing alone. The specification based on formal method is recommended for safety system software. But there exist various kinds of formal methods, and this variety of formal method is recognized as an obstacle to the wide use of formal method. In this paper six different formal method have been applied to the same part of the functional requirements that is calculation algorithm intensive. The specification results were compared against the criteria that is derived from the characteristics that good software requirements specifications should have and regulatory body recommends to have. The application experience shows that the critical characteristics should be defined first, then appropriate method has to e selected. In our case, the Software Cost Reduction method was recommended for internal condition or calculation algorithm checking, and state chart method is recommended for the external behavioral description. (author)

[en] The interaction of molten metal drop and coolant is numerically analyzed to investigate the mechanism of fragmentation in vapor explosion. The numerical study is carried out by using a developed simulation code based on multi-phase thermal hydraulic model, which includes physical phenomena required for the analysis: heat transfer, mass change, liquid evaporation and treatment of surface. Several computational techniques are also implemented to improve the efficiency and stability of the numerical scheme. The obtained numerical results show that the growth of spikes on the molten metal drop surface is similar to that observed in Ciccarelli's experiment. The numerical study suggests that quick growth of spikes is the essential mechanism of fragmentation, which is caused by Taylor instability. (author)

[en] The current concept of the EPR (European pressurised water reactor) relies on a sufficiently homogeneous spreading of the melt in order to ensure its coolability after a passive initiation of flooding by water. The conditions under which a complete spreading can be expected are the subject of current theoretical and experimental results. The CORFLOW code allows to treat three-dimensional non-isothermal free surface flow. The influence of cooling on the spreading is modelled by a temperature dependent viscosity. The increase of the viscosity in the thermal boundary layer of the melt can eventually lead to a stop of the melt front. The experimental findings from the KATS series are analysed and CORFLOW results are presented. In addition the available similarity solutions are also used to validate the CORFLOW code. (orig.)