NWIS Signatures for Confirmatory Measurements With B33 Trainers

Nuclear weapons identification system (NWIS) signatures have been used successfully to confirm that B33 trainer parts, shipped from military bases to the Oak Ridge Y-12 Plant, were, as declared by the shipper, nonenriched uranium. The B33 was a gun-assembled weapon consisting of two components. Verification was accomplished by comparing signatures for B33 trainer parts with signatures for mock-ups made with depleted uranium packaged at the Y-12 Plant in Ml02 containers. Measurements with a normal production war reserve (WR) Component 2 part and calculations for a normal WR Component 1 part showed the very high sensitivity of the frequency- domain signatures to the presence of enriched uranium. Some measured frequency-domain signatures were greater than a factor of 100 different for the WR units. These verifications alleviated the criticality safety and safeguard concerns for material returned to the Y-12 Plant for dismantlement. This work in 1993 was part of the weapons dismantlement program at the Y-12 Plant, with hardware partially funded by the U.S. Department of Energy (DOE) Office of Arms Control and Non- Proliferation through the National Security Program Office of the Y-12 Plant. The weapons dismantlement program dismantles nuclear weapons components and trainers, safely stores fissile materials, and disposes of the wide variety of materials in an environmentally acceptable manner, meeting all applicable DOE, state, and federal regulations.