Application of the Direct Statistical Approach on a Multisurface Splitting Problem in Monte Carlo Calculations

Abstract

The direct statistical approach was used recently to obtain analytic expressions for the second moment and the average time per source particle in a general case of multisurface geometry splitting. A practical algorithm is given for the calculation of the second moment as a function of the splitting parameters on the surfaces. The algorithm is used to calculate an explicit expression for the efficiency in a problem involving streaming of neutrons in a straight section of a concentric coolant pipe of a fast reactor. The results are used to obtain the optimum splitting range on four surfaces.