Radiation Exposures in Fabricating ²³³U-Th Fuels

Radiation levels and exposures associated with the operation of the ORNL Kilorod Facility for the fabrication of ²³³UO₂-ThO₂ fuel were determined and are analyzed. Comparison between the measured activity of ²⁰⁸ Tl during a typical sequence of operations and the calculated activity of pure ²³² U demonstrates the effects of the several fabrication steps. Conceptual design calculations for a semi-continuously operating plant indicate that up to 100 kg/d of mixed oxide containing 200 parts/10^{6 232} U can be processed using 2-in.-thick (5.1 cm) lead-equivalent shielding.