Method of forecasting power distribution of FBR type reactors

Purpose: To enable accurate forecasting for the power distribution of a reactor core by calculating the power distribution by way of an approximate calculation method and then rapidly correcting the calculation result by the use of variation coefficients of the experimental data for the inlet and outlet temperatures of fuel assembly, flow rate and neutron fluxes outside of the reactor between the operation start-up time and the present time. Method: The present power distribution of a FBR type reactor is calculated in a short time by using an approximate calculation method based on one group coarse mesh diffusion calculation. Then, the result of the calculation is corrected by utilizing the variation coefficients of the experimental data for the inlet and outlet temperatures of fuel assembly, flow rate and neutron fluxes outside of the reactor between the operation start-up time and the present time, to thereby estimate the present power distribution of the reactor core in which burn-up is advanced. By correcting the result of the approximate calculation for the present power distribution of the reactor core by utilizing the experimental data, the power distribution for the reactor core can be estimated at high accuracy. (Moriyama, K.)