Combined Method of Calculating Nuclear Power Facility Protection

This article is devoted to a method for calculating the radiation protection based on combined use of the Monte Carlo method and the method of characteristics. The method implements a scheme for automatic reduction of dispersion CADIS (Consistent Adjoint Driven Importance Sampling) based on the solution of a multigroup adjoint problem by the method of characteristics using the MCCG3D code. The presented method makes it possible to generate spatial-energy weight windows on an auxiliary grid for Monte Carlo calculations. The general structure of the method including the results of model calculations showing its efficacy is presented.