A probabilistic risk assessment of an AGN-201M reactor

The fundamental liability of any nuclear reactor is the possibility of exposing the public and environment to excessive levels of nuclear radiation. This paper addresses the risk and potential vulnerability assessment of a maximum hypothetical release accident (MHRA) for the AGN-201M reactor located at the University of New Mexico (UNM). The MHRA is defined as the total release of all radiological effluents from the reactor facility to the environment. This paper presents the results of a levels I and II probabilistic risk assessment (PRA) through the disclosure of the following: (1) internal initiating events at full-power operation; (2) dominant accident sequences in the reactor event trees and their frequencies; and (3) radioactive material transport phenomena. The methodology used in the assessment follows NUREG/CR-4550 to include a detailed description of the reactor, its operational domain, and its safety systems. This assessment includes analysis of the safety systems, performance of the confinement structure and other mitigative systems, and identification of the fission products produced by the reactor. The internal events include both human error and random equipment failure. The source term is characterized for the worst-case scenario only, since the magnitude of the escaping effluents is deemed ineffectual for any subcategory release