Abstract

In a high dominance ratio system, the problem of slow fission source convergence is faced during the Monte Carlo criticality calculation. The Wielandt method and the Superhistory method have been proven to reduce the dominance ratio. Still, the Wielandt method and the Superhistory method have also proven to be unable to accelerate the convergence of the fission source. With the estimation of errors in the cumulative fission source and the batch size optimization methodology, the optimal batch size growth for the Wielandt method and the Superhistory method is proposed. Compared with the direct simulation with the optimal batch size growth, the Wielandt simulation and the Superhistory simulation better use the optimal batch size growth. A single fuel rod model was tested, and the results show that the new method is helpful for the acceleration of fission source convergence.

摘要

在高优势比系统中，在蒙特卡罗临界计算过程中面临裂变源收敛慢的问题。Wielandt 方法和 Superhistory 方法已被证明可以降低优势比。尽管如此，维兰德方法和超历史方法也被证明无法加速裂变源的收敛。通过累积裂变源中的误差估计和批量大小优化方法，提出了维兰德方法和超历史方法的最佳批量大小增长。与具有最佳批量大小增长的直接模拟相比，维兰德模拟和 Superhistory 模拟更好地使用了最佳批量大小增长。测试了单个燃料棒模型，