Nuclear Safety Evaluation of Units Containing 238Pu and 239Pu as Oxides

摘要

This study evaluates the nuclear safety of (sup 238)Pu and PuO(sub 2) under a variety of conditions for shipping and storage and is applicable to mixtures of (sup 238)Pu-(sup 239)Pu oxides. Evaluations were made for a three-container shipping package (Plutonium Finishing Shipping Cask) for compliance with AECM Chapter 0529 Shipping Regulations. Some calculations were also made for the two inner containers as a storage unit to extend the usefulness to cover B-Line storage. This safety analysis was developed with (sup 239)Pu and (sup 238)Pu cross sections using KENO, a multigroup Monte Carlo criticality program. Conservative allowances were made so that the results are valid for all mixtures of (sup 238)Pu-(sup 239)Pu. For storage conditions a planar array one unit tall of two or three container packages is shown to be safe regardless of water moderation provided the spacing is 2.375 inches center-to-center or greater.