Studies of uranium—cerium admixture solutions by EDXRF spectroscopy

Abstract

Uranium and cerium were studied in nitric acid solutions after presentation to an energydispersive x-ray fluorescence (EDXRF) spectrometer on filter-paper fixed on Scotch tape. ce La and U La peaks were used as aaalyte lines after excitation with a tungsten tube target at low potential (20 kV). These non-conventional excitation conditions were considered to be suitable for low contents of cerium strongly but high contents of uranium weakly in a nuclear fuel. Lower net integrated line intensities observed in an actinide as compared with a lanthanide are discussed along with the scattered, Auger and Coster-Kronig intensities responsible for the production of background before calibrations with known concentrations. Difiiculties in establishing an explicit relationship between these with change in matrix composition are discussed. The known concentrations of the mixed solutions when compared with the results from various computer programs using regression analysis showed that the algorithm developed by Plesch and Thiele for Siemens is better than the others. An accuracy of <2% was achieved. The importance of certified, standard or simulated reference materials is realized for quality analysis of occasional samples.