Los Alamos National Laboratory`s mobile PAN (Passive/Active Neutron) system for assay of TRU waste in 55 gallon drums

We describe the refurbishment, reactivation and rough calibration of a mobile second generation Passive/Active Neutron (PAN) assay system previously owned by the Carlsbad Area Office (CAO) and stored at the Idaho National Engineering Laboratory - Lockheed Idaho Technology Center (INEL-LITC). This system was transferred to LANL a little over one year ago. After substantial refurbishment for operations, including installation of operating software developed at INEL-LITC, we have completed a rough calibration of the system in preparation for the Performance Demonstration Program (PDP) expected to begin in the near future. We discuss compensation for the waste matrix neutron moderating and absorbing characteristics and present some data acquired during the calibration process which points out the possible waste matrix effects on the results of an assay. Future plans are also discussed.