УТОЧНЕНИЯ НЕЙТРОННО-ФИЗИЧЕСКОЙ МОДЕЛИ РЕАКТОРА СМ-3 ДЛЯ РАСЧЁТОВ С ИСПОЛЬЗОВАНИЕМ ИМИТАТОРА IMCOR_SM

Abstract

When calculating the maintenance of the operation of nuclear reactors, the most popular are calculations according to precision programs based on detailed core models, which make it possible to predict the characteristics of the upcoming reactor campaign or to calculate the conditions for irradiation of materials in it. Such calculations are of particular importance when justifying the modernization of a reactor or loading new irradiation devices. With small changes in the layout of the core, it is possible, on the basis of operational data, to estimate the magnitude of the systematic error of the design model arising from simplifications in the description of the core, and then make an appropriate correction later. When significant changes take place in the core, for example, during the modernization of the reactor, such corrections can no longer be used, since such an approach can lead to additional uncertainty in the calculations. Due to the fact that neutron-physical calculations in carrying out these works are the most important, the refinement of calculation models and finding the sources of systematic uncertainty is of great practical importance. The paper describes the refinements of the design model of the SM reactor. The division of beryllium into separate zones with the same nuclide composition has been clarified. An optimal list of nuclides for calculations was selected, and the effect of thermal expansion of materials on reactivity was investigated. The approach used by the authors is applicable to other models of research reactors.