DETERMINATION OF NEODYMIUM-148 IN IRRADIATED URANIUM AND PLUTONIUM AS A MEASURE OF BURNUP

摘要

Nonradioactive fission product Nd 148 is determined by isotopic dilution mass spectrometry. The isotopic diluent is a blend of Nd150, U233. and Pu242. After an ion exchange separation of Pu, U, and Nd, each fraction is mounted on a Re filament for mass spectrometric analysis. Burnup (atom percent fission) is computed from the Nd148 -to-fuel ratio to an accuracy of 1. 2% (1 a) which includes a 0. 7% single instrument uncertainty in the Nd148 -to-fuel ratio and a 1. 0% uncertainty in the Nd148 fission yield.