OPERATIONAL USE OF NWIS FOR STORAGE VERIFICATION OF WEAPONS COMPONENTS AT THE OAK RIDGE Y-12 PLANT

Nuclear weapons identification system (NWIS) signatures are in use for verification of nuclear weapons components in storage at the Oak Ridge Y-12 Plant. They have recently been used to resolve a Department of Energy Inspector General’s audit finding and to resolve another deficiency in Nuclear Material Control and Accountability (NMC&A) with regard to confirmation of weapons components in storage at the Y-12 Plant. This method is now being used for regular confirmation of inventory. NWIS correlation measurements with 252Cf produce some signatures, in particular the cross power spectral density between the detectors and the source, that are insensitive to background radiation or to changes in background. Thus, these signatures are very useful for measurements in large storage arrays.