EXPLORING THE USE OF A DETERMINISTIC ADJOINT FLUX CALCULATION IN CRITICALITY MONTE CARLO SIMULATIONS

The paper presents a preliminary study on the use o f a deterministic adjoint flux calculation to improve source convergence issues by reducing the number of iterations needed to reach the converged distribution in criticality Monte Carlo c alculations. Slow source convergence in Monte Carlo eigenvalue calculations may lead to underesti mate the effective multiplication factor or reaction rates. The convergence speed depends on th e initial distribution and the dominance ratio. We propose using an adjoint flux estimation to modi fy the transition kernel according to the Importance Sampling technique. This adjoint flux is also used as the initial guess of the first generation distribution for the Monte Carlo simulat ion. Calculated Variance of a local estimator of current is being checked.