Year
2000
Abstract
Nuclear material consolidation and conversion of HEU to LEU is an essential element of the decommissioning process in Russia. Among other things, it is important to assure the receiver facility that the material it receives meets the acceptance criteria for proper operation of the re-packaging and down blending process. It is equally important for the shipper facility to check the shipments against the same criteria to be assured of acceptance at the receiver facility. Such measurements, however, present significant procedural challenges arising from calibration, operation, and sensitivity variations between different chemical and physical forms of the material. The most practical method to overcome these difficulties is to deploy a self-contained instrument van that is transported with the material shipment and is used to make the assays at the shipper site or, if required, at both the shipper and receiver sites. The measurement process as described also provides for detection of diversion. The same measurements can also ensure that the input material to the down blending operation meets the MPC&A contract terms and programmatic transparency objectives regarding the “attractiveness” of the HEU feed material. These terms make it essential that the material be measured for both total uranium concentration and for its U-235 enrichment.