Consequence analysis of a hypothetical contained criticality accident in the Hanford Critical Mass Laboratory

Abstract

The original hazards summary report (i.e., SAR) for the CML addressed the consequences of a hypothetical accidential critical excursion occurring with the experimental assembly room open. That report indicated that the public would receive insignificant radiation exposure regardless of the type of atmospheric condition, while plant personnel could possibly receive exposures greater than the annual exposure limits for radiation workers, when a strong inversion existed. This analysis investigates the consequencs of a hypothetical accident criticality occurring with the experimental assembly room sealed. Due to the containment capabilities designed and built into the critical assembly room, the consequences are greatly reduced below those presented in HW-66266. Despite the incorporation of many extremely conservative assumptions to simplify the analysis, the radiation doses predicted for personnel 100 meters or more distant from the CML are found to be smaller than the annual radiation dose limit for members of the public in uncontrolled areas during routine, nonaccident operations. Therefore, the results of this analysis demonstrate that the occurrence of a hypothetical critical excursion within the sealed experimental assembly room at the Hanford Critical Mass Laboratory presents only a small, acceptable risk to personnel and facilities in the area and no additional safety systems or controls are needed for the continued safe operation of the CML. 11 references, 4 tables. (ACR)