Abstract

Whether to use highly enriched uranium (HEU) or low-enriched uranium (LEU) in space reactors is a highly debated topic. Most analyses focus on performance as the principal determinant of use, where HEU has inherent advantages. This paper identifies seven dimensions along which rigorous comparisons must be made to evaluate whether HEU or LEU is an appropriate enrichment level for space nuclear systems. These dimensions are performance, safety, security and nonproliferation, timeliness of a system to come to fruition, fuel availability, cost, and ability to include commercial partners. Our analysis shows that HEU and LEU systems provide different advantages depending on the dimension of interest, and whether the United States continues to use HEU or switches to LEU is ultimately a policy decision, not a technical one.

摘要

在空间反应堆中使用高浓缩铀 (HEU) 还是低浓缩铀 (LEU) 是一个备受争议的话题。大多数分析都将性能作为使用的主要决定因素，其中 HEU 具有先天优势。本文确定了七个维度，必须沿着这些维度进行严格的比较，以评估高浓铀或低浓铀是否是空间核系统的适当浓缩水平。这些维度是性能、安全、安保和防扩散、系统实现的及时性、燃料可用性、成本以及包括商业合作伙伴的能力。我们的分析表明，高浓铀和低浓铀系统根据利益的维度提供不同的优势，美国是继续使用高浓铀还是改用低浓铀最终是一项政策决定，而不是技术决定。