Calculation of pin power distributions in fuel subassembly of China Experimental Fast Reactor

Pin power distributions in the China Experimental Fast Reactor(CEFR) should be calculated for thermal hydraulics calculation. Monte Carlo program was used to calculate the pin power distributions and the statistical error of the calculation results is guaranteed to be less than 0.8%. Another program based on nodal diffusion theory, NAS, was used to provide reference for the Monte Carlo results of pin power distributions. It is indicated that the maximum deviation of pin power distributions obtained with the two programs is less than 3%. Thus, application of Monte Carlo program to calculation of pin power distributions in the fuel subassembly of CEFR is credible, and moreover can be generalized to reactor design.