Year
1985
Abstract
An analysis is made of the role of shipper and receiver measurements in safeguarding special nuclear materials (SNM) transferred from one facility to another, with emphasis on the case where the receiver requires an analytical accounting measurement of the transferred SNM and does not need the material for process purposes at the time of receipt. Seven possible diversion periods are considered, ranging from the interval between the shipper's final accounting measurement on the material and the time it is placed in the shipper's vault, through the actual transport of the material between facilities, to the time the material is removed from the receiver's vault and placed in the process. The detection power of various combinations of six possible shipper/ receiver measurements for these diversion opportunities is then evaluated; the measurements considered include the shipper's and receiver's accounting measurements, the latter at two possible times, and various nondestructive assay (NDA) confirmatory measurements. It is concluded that all safeguards measurement objectives can be met by a combination of a shipper's accounting measurement at the time the material is removed from the process, an appropriate shipper's NDA confirmatory measurement either immediately after canning or immediately before shipping, an equivalent receiver's NDA confirmatory measurement immediately after the material is received, and a receiver's accounting measurement when the material is placed in the process. Furthermore, it is found that a receiver's analytical accounting measurement immediately after receipt when the material is not yet required for process has dubious safeguards value.