Current status of the multi-isotopic transuranic-waste-assay system

A 208-1 barrel sized working version of a multiisotopic transuranic assay system using both passive neutron multiplicity and pulsed active measurements to identify and quantify spontaneous neutron emitters and fissile TRU isotopes was designed and constructed. The system can separately quantify up to seven individual transuranic isotopes under favorable conditions with the intrinsic sensitivity to screen or assay barrels at or below the 10 nCi/g transuranic level. Three sigma sensitivity for Pu-239 is measured at about 0.5 mg. A large range of waste matrix materials was accommodated by the system, as well as extremes in both gamma ray and neutron backgrounds.