Вибір оптимальних умов опромінення зразків у матеріалознавчому каналі ядерного реактора ВВР-М

Abstract

The methodology for choosing the optimal conditions for irradiation of specimens in the material testing channel of the VVR-M research nuclear reactor is presented in the article. The solution to such a problem is necessary to justify the possibility of irradiation of specimens in the material testing channel under given irradiation conditions. In this case, the irradiation conditions include not only the height distribution of the neutron flux density, but also the spectrum of neutrons and the temperature of the specimen in the material testing channel. This approach optimizes the work of VVR-M reactor by placing the maximum possible number of specimens in the material testing channel for irradiation. Also, the optimization of the VVR-M operation involves choosing the location of the research channel in the VVR-M core, where, during the planned irradiation time, the maximum flux density of fast neutrons or neutrons of other energies will be reached, depending on the task. The neutron-physical model of the research nuclear reactor VVR-M in the calculation code SCALE was used for research. The reliability in the determination of neutron-physical characteristics in the VVR-M material testing channel is confirmed by the results of validation carried out at the previous stage of research. It is shown that in order to ensure the necessary accuracy in the determination of the neutron flux parameters in the material testing channel, it is necessary to take into account the fuel burnup, as well as the actual scheme of fuel assemblies rearranging in the VVR-M core for various fuel loads. The results of calculations of important neutronphysical characteristics of the model of a VVR-M nuclear reactor for fuel loading, which is in operation today, on the basis of which it is possible to optimize the choice of the location of the material testing channel in the VVR-M core are presented in the article.