Solution of practical problems of IRT-M reactor operation on the basis of three-dimensional multigroup program

Based on the three-dimensional multigroup program, the results of calculation of physical characteristics of the IRT-M research reactor with the system of loop channels have been analyzed. The program takes as a basis the method of synthesis of solution of two-dimensional and one-dimensional problems in ten-group diffusive approximation (the SIN-IRT program on the ES-1061 computer). The results of the program test on the basis of calculation of criticality of the reactor with different position of control rods in the presence of loop channels and without them are given. It is shown, that the deviation of keff calculated value for four critical conditions amounts no more than 1 %. The distribution of neutron fluxes and reactivity excess has been obtained, taking into account the actual core geometry and positions of control rods. The effect of positions of control rods on distribution of energy discharge along the loop channel has been considered. It is important in forecasting the fuel burnup in experimental loop channels in the process of resource tests