Abstract

Algorithms used to generate Monte Carlo input decks and to analyze the output over a range of uranium mass, water volume, and particle size in a regular lattice are described. The algorithms produce input decks for both homogeneous and heterogeneous, regular-lattice systems of 20% enriched uranium metal and water and then analyze the results to determine the minimum critical mass over a range of input mass and particle size. The output is presented and analyzed for a 20% enriched uranium metal and water system, and comparisons to existing technical reports and safety guides are discussed. Two particular existing recommendations are tested and compared with new results: the boundary between a homogeneous system and a heterogeneous system, and the recommended margins of safety that can be applied to account for the effects of heterogeneity.

摘要

描述了用于生成 Monte Carlo 输入甲板和分析在一定范围内的铀质量、水体积和规则晶格中的颗粒大小的输出的算法。该算法为 20% 浓缩铀金属和水的均质和异质规则晶格系统生成输入平台，然后分析结果以确定输入质量和颗粒尺寸范围内的最小临界质量。对 20% 浓缩铀金属和水系统的输出进行了介绍和分析，并讨论了与现有技术报告和安全指南的比较。测试了两个特定的现有建议并将其与新结果进行比较：同构系统和异构系统之间的边界，以及可用于解释异质性影响的推荐安全边际。