Shuffler calibration and measurement of mixtures of uranium and plutonium TRU-waste in a plant environment

The active-passive shuffler installed and certified a few years ago in Los Alamos National Laboratory's plutonium facility has now been calibrated for different matrices to measure Waste Isolation Pilot Plant (WIPP)-destined transuranic (TRU)-waste. Little or no data presently exist for these types of measurements in plant environments where there may be sudden large changes in the neutron background radiation which causes distortions in the results. Measurements and analyses of twenty-two 55-gallon drums, consisting of mixtures of varying quantities of uranium and plutonium, have been recently completed at the plutonium facility. The calibration and measurement techniques, including the method used to separate out the plutonium component, will be presented and discussed. Particular attention will be directed to those problems identified as arising from the plant environment. The results of studies to quantify the distortion effects in the data will be presented. Various solution scenarios will be indicated, along with those adopted here