Criticality safety study of unirradiated Cintichem target storage

摘要

Sandia National Laboratories has been chosen by the US Department of Energy as the primary domestic source for the production of molybdenum-99, utilizing the Annular Core Research Reactor. The method to be used to produce (sup 99)Mo through the fission of (sup 235)U in 93% enriched UO(sub 2) is based on the process formerly used by Cintichem, Inc. of Tuxedo, New York. The UO(sub 2) is electroplated in a thin coating to the inside of stainless steel Cintichem targets which will be irradiated in the central region of the reactor core. The proposed on-site storage plan for the unirradiated targets is to store them in a dry, secure compartment similar to a file cabinet. Each cabinet drawer will be initially filled with targets and emptied as targets are removed for irradiation. The main objective of this analysis was to postulate and model a set of incredible accident scenarios beyond the proposed storage plan which would possibly induce criticality with the targets in the safe, and determine the k-effective and its associated standard deviation for these conditions. A parametric analysis was performed using Los Alamos National Laboratory's MCNP (Monte Carlo Neutral Particle) code, Version 4A.