Year
1995
Abstract
Nuclear weapons identification system (NWIS) signatures have been used successfully to confirm that B33 trainer parts in their Ml02 containers, shipped from military bases to the Oak Ridge Y-12 Plant, were as declared by the shipper to be nonenriched uranium. The verification was accomplished by comparing signatures for B33 trainer parts with signatures for mock-ups made with depleted uranium packaged at the Oak Ridge Y-12 Plant in M102 containers. These verifications were conducted in a timely, reliable manner and produced no false positives for the 512 verifications. As many as 32 verifications were performed in 1 day (normal 8-h shift). The verification measurements also revealed that the mass of eight Component 1 parts were not as declared by the shipper. Ten Component 2 parts showed anomalously high values of the coherence between the source and detectors, identifying increased transmission of particles through the parts, suggesting less nonenriched uranium in the containers. This finding was also confirmed when the containers were opened and it was found that the parts had been modified which reduced the mass of uranium ~4%. Other deviations in packaging that produced variations were all confirmed when the parts were removed from the container. NWIS signatures have been demonstrated to be adequate for shipper-to-shipper confirmatory measurement within the U. S. Department of Energy (DOE) and between the U.S. Department of Defense (DOD) and DOE. A nonintrusive use of NWIS signatures is demonstrated and would allow the use of this method by foreign nations at DOE or DOD facilities. A field-deployable system, based on a laptop personal computer system, is under development. Although the NWIS method was developed for nuclear weapons identification, the development of a small processor now allows it to be also applied in a practical way to subcriticality measurements, nuclear fuel process monitoring and quantitative nondestructive assay of special nuclear material.