PNNL

Abstract

The research described herein discusses the use of fluorination as a rapid separations technique for trace quantification of short lived isotopes. Fluorination can rapidly remove prominent, interfering radionuclides from the target and improve the detection sensitivity for refractory analytes. A single crystalline sample of 238UO2 was exposed to a 14 MeV neutron source to produce a mixed fission and activation product sample. Selective removal of ?2e 1010 atoms of U, Mo, Rh, Tc, Sb, I, and Te as volatile fluorides from a 3.4e11 atoms of Zr, Ag, Cd, Ba, La and Ce as their non-volatile fluorides was achieved through high-temperature (760-805 K) fluorination using NF3 gas. Gamma spectroscopy was used to observe the before and after activities of prominent gamma emitters within the sample. Partial volatilization of Zr, Ag, Ru, and 239Np was also observed with virtually no loss in the Ba, La, and Ce activities measured following treatment. The dilute nature of the fission product population in the freshly irradiated 238UO2 and their volatility behaviors are discussed.