ESTIMATION OF AD JOINT-WEIGHTED KINECTICS PARAMETERS IN MONTE CARLO FORWARD CALCULATIONS

摘要

The effective delayed neutron fraction, ss_(eff), and the prompt neutron generation time, △, in the point kinetics equation are adjoint-weighted quantities. There have been some approaches to estimating them based on the use of either the constant source adjoint function or the self-consistent adjoint function. In this paper, we derive the MC algorithms for computing ss_(eff) and △ weighted by using two kinds of the adjoint functions that can be obtained from the MC forward eigenvalue calculations. The results of applications for the infinite homogeneous 2-group problems and some critical facilities are compared with analytic solutions and experimental measurements, respectively. It is demonstrated that ss_(eff) and △ from the use of the self-consistent adjoint function as the weighting function agree better with measurements within a 3% error.