Abstract: In order to improve computational efficiency of large and complex problems, a Monte Carlo Continuation Calculation method is proposed for structures with multiple spatial surfaces and complex curved surfaces. In this method, the external boundary of the structure is used as the source for the continuation calculation, and the sum of the calculation results of the source writing process and the continuation calculation process is taken as the final result. In terms of efficiency improvement, the method can avoid repeated calculation of the same structure in the process of direct calculation by means of one source writing process and several continuation calculation processes, which greatly improves the computational efficiency. A typical reactor structure calculation model is established by MCNP, and the continuation calculation results of four structural schemes are compared with those of direct calculation method. The results show that the calculation of the continuation method is consistent with those of the direct method, and the efficiency of the continuation calculation method is about three times higher than that of the direct calculation method. Therefore, the Monte Carlo continuation Calculation method proposed in this study can achieve significant efficiency improvement for large and complex problems involving a large number of repeated calculations.

Key words: Monte Carlo method, continuation calculation, efficiency, multiple surface, complex surfaces