Comparison of materials accounting in conversion and coconversion processes

Materials accounting systems performances are compared for plutonium nitrate-to-oxide conversion [Oxalate (III)] and uranium-plutonium coconversion (Coprecal and modified Coprecal). These processes have the same design basis plutonium throughput and achieve this throughput in parallel operating lines. However, the process line configurations differ. In comparing the materials loss detection sensitivities for the three processes, we find better materials loss detection sensitivity for the Oxalate (III) process than for either of the two Coprecal processes, better single-balance detection sensitivity for the original Coprecal than for the modified Coprecal, and better long-term detection sensitivity (> 1d) for the modified Coprecal than for the original Coprecal. Sensivity differences result from differences in in-process inventories, feeding arrangements, and scrap generation