Questions Raised by Application of Standards for Criticality Accident Alarm System Proposal of a 'Most Credible Accident of Concern' Concept for Aqueous Media

摘要

While the importance of the above mentioned CAAS standards is unquestionable, this study proposes the following clarifications: 1. Use of dose rate alone to detect a criticality accident does not guarantee that dose at 2 m will be less than 0.2 Gy if the accident is not quenched by appropriate safety actions; To improve understanding of the standards, the concept of "minimum accident of concern" could be usefully replaced by "number of fissions corresponding to a minimum dose of 0.2 Gy". 2. For accidents occurring in aqueous fissile media, the "most credible accident of concern" concept proposed in this document could both facilitate criticality safety assessment and make it more realistic.