Monte Carlo Inter-Cycle Correlation Reduction with the Application of the Modified Power Method

Abstract

The modified power method has been applied to reduce the inter-cycle correlation of the Monte Carlo simulation in this study. Previously it has been developed and implemented in the Monte Carlo simulation to accelerate the source convergence. The convergence of the original Monte Carlo simulation determined by the decay rate of the 1st mode in the source, which will finally converge to the 0th mode. The 1st mode is also the most important origin of the inter-cycle correlation of the sources of different cycles. The modified power method can give the first several eigenmode solutions at the same time, so it is efficient for both source convergence acceleration and inter-cycle correlation reduction by subtracting the higher modes from the source. The 1D slab problem is modeled in this study to demonstrate the performance of the modified power method.