TEST AND EVALUATION OF A HIGH-SENSITIVITY ASSAY SYSTEM FOR BULK TRANSURANIC WASTE

Year
1983
Author(s)
J.C. Pratt - Los Alamos National Laboratory
T.H. Kuckertz - Los Alamos National Laboratory
J.T. Caldwell - Los Alamos National Laboratory
D.A. Close - Los Alamos National Laboratory
F.J. Schultz - Oak Ridge National Laboratory
W.E. Kunz - Los Alamos National Laboratory
K.W. Haff - Oak Ridge National Laboratory
Abstract
During the past year, we tested and evaluated the performance of an assay system that accommodates 55-gal. drums of transuranic waste at Oak Ridge National Laboratory. This neutron assay system provides a routine assay of fissile transuranic isotopes to the 1-mg sensitivity level with a pulsed active neutron interrogation based on the differential dieaway technique. A highly sensitive passive neutron measurement determines the content of spontaneous fission transuranic isotopes in each drum as well as an upper-bound estimate of the total alpha activity. All components of the combined, pulsed active and passive neutron assay system performed well on a routine basis during the test-and-evaluation period. We performed more than 400 combined passive and active assay measurements of waste drums at Oak Ridge. One-fifth of the initial set of waste drums measured contain less than 100 nCi/g of total transuranic isotopes and thus qualify legally as nontransuranic waste.