Method of Nuclear Loss Calculation for Bulk Handling Process in PCDF

In a plutonium facility, loss of plutonium due to nuclear decay (nuclear loss) is evaluated and reported. Conventionally, the nuclear loss i calculated for each batch from plutonium weight, isotopic ratios and period. So, it is necessary to find clearly the diagram of batches. A new method to calculate nuclear loss without finding the batch diagram was designed and applied to the bulk handling process with process inventories including small samples in the Plutonium Conversion Development Facility (PCDF). A process area that includes all batches and process inventories is supposed. The total inventory at PIT in the area and the inventory change from/to the area are resolved onto each isotope. The nuclear loss is calculated for each isotope at the time of inventory changes. Results are added and reported periodically.