Three-energy gamma-ray absorptiometer (TEGA) for nondestructive assay of plutonium and uranium in solution

An experimental approach for the nondestructive characterization of plutonium and uranium solutions is presented. The technique relies on the transmission of photons of three different properly chosen energies, and allows an independent and simultaneous determination of plutonium and uranium by the different absorption of the two elements in the range of K-edge energies. The performances achievable have been evaluated through measurement of a set of solutions using the hardware of the compact K-edge densitometer. The plutonium and uranium concentrations ranged from 50 to 150 g/l. In this concentration range, the relative precision is below 3.0% for uranium assay and below 6% for plutonium assay. Further improvements of the performances of the technique are discussed. 3 refs., 9 figs., 1 tab.