Error Propagation as a Tool for Evaluating Process Performance

Calculation of the limit of error of inventory difference (LEID) has traditionally been done upon completion of a physical inventory of nuclear materials. LEID can be used as a performance tool and a sensitivity indicator during a processing campaign. A model has been developed which correlates product output with process performances given an a priori desired sensitivity. The model can be used as an inventory frequency indicator instead of the traditional time dependent requirements. The model requires more frequent inventories for poor process performance and allows longer processing campaigns for superior process and measurement capability. The model also provides a risk assessment capability of a process material balance area (MBA).