Estimation of kinetics parameters by Monte Carlo fixed-source calculations for point kinetic analysis of accelerator-driven system

The point kinetics model for an initially subcritical system such as the accelerator-driven system (ADS) requires the adjoint-weighted kinetics parameters to be estimated in its reference subcritical state with external sources. Monte Carlo (MC) algorithms are newly developed to calculate the kinetics parameters weighted by the adjoint function, which is the solution to the inhomogeneous adjoint equation, in the MC fixed-source mode calculations. The developed algorithm is verified through a simple two-group problem by comparing with analytic solutions. The one-point kinetics analyses using the estimated kinetics parameters are applied for beam trip transient problems and a control rod drop experiment in ADS at the Kyoto University Critical Assembly.