关键词: 最小临界事故, 瞬发源项, 核临界事故报警系统, 布置方法, 报警阈值

Abstract: This paper expounds the significance and principle of the layout of nuclear criticality accident alarm system in spent fuel reprocessing plant, analyzes the mechanism of potential nuclear criticality accident, and preliminarily establishes a set of scenario hypothesis analysis method for nuclear criticality accident. The calculation method of the source term of the minimum criticality accident and tallying of three-dimensional dose field distribution of equipment room is studied. The method of contour plot of the minimum criticality accident dose field distribution of all equipment is applied to optimize selecting the appropriate location of the nuclear criticality accident alarm system from many dose field distribution maps, so as to ensure that all equipment with nuclear criticality accident risk can be covered. The principle and specific method of probe type selection of the nuclear criticality accident alarm system are also analyzed.

Key words: minimum criticality accident, instantaneous source term, nuclear criticality accident alarm system, layout method, alarm threshold