Preliminary high level waste conceptual cask designs and an assessment of a clad waste cask

Abstract

Neutron and gamma-ray transport calculations in one- and two-dimensional cylindrical geometry have been performed for a number of high-level waste and cladding waste conceptual cask shield designs. Stainless-steel-lined depleted uranium and lead were the primary gamma-shield materials considered in this study. The thicknesses of these shield-material regions were varied until the total dose rate, at 91.44 cm (3 ft) from the cask surface, was less than 1000 mrem/hr for accident environments. Neutron-shield materials including borated beechwood, water, serpentine, and calcium borate were then added to the cask surface until the total dose rate, at 1.83 m (6 ft) from the cask surface, was less than 10 mrem/hr for normal operating conditions. It was determined that the best combination of these shield materials, based on overall cask dimensions was depleted uranium and borated beechwood.