SOME CONSIDERATIONS ENABLING DYNAMIC INVENTORY IN FUEL CYCLE FACILITIES

The overall objective of this paper is to describe a technique for improving the capability of taking accurate physical inventories in fuel cycle facilities with a minimum of perturbation to plant operations. This will facilitate more frequent and more accurate determinations of material unaccounted for (MUF) and the limit of error of material unaccounted for (LEMUF), thus improving the ability to detect diversion in a timely manner. The most difficult part of an inventory is obtaining the measurements of material in process equipment. The current typical technique includes the draindown and cleanout of equipment, and the collection, sampling, and assay of removed material. This procedure results in a major disruption of operations in several ways, all of which affect adversely the efficiency of plant operations. The loss of production is the obvious, and probably most significant, adverse affect. To this must be added the effects of restoring equilibrium conditions after start-up, and the effects of recycling off-specification material collected during equipment cleanout and process start-up.