Characterization of spent nuclear fuels by ion chromatography–inductively coupled plasma mass spectrometry

Abstract

Ion chromatography (IC) coupled to ICP-MS was applied to the characterization of two different spent fuel samples [uranium oxide (UO₂) and mixed uranium–plutonium oxide (MOX)] and the results were compared with those obtained by other techniques. Isotope dilution analysis with ion chromatographic separation was applied to the determination of the fission products (Rb, Sr, Cs, Ce, Nd, Sm, Eu and Gd). The standard additions method was employed for the determination of monoisotopic fission products and actinides (Y, La, Pr, ¹⁴⁷Pm, ²³⁷Np, ²⁴¹Am, ²⁴³Am and ²⁴⁴Cm). Total U and Pu were determined only by ID-TIMS. Nd, Am and Cm isotope concentrations were determined also by ID-TIMS. ¹⁴⁴Ce, ¹⁵⁴Eu, ¹³⁴Cs and ¹³⁷Cs were determined in parallel by gamma spectrometry. Based on the ID-TIMS results for U, Pu and ¹⁴⁸Nd, fuel burn-up was calculated and the value introduced into the computer code KORIGEN in order to calculate the complete fuel inventory based on the known irradiation parameters for the two fuels. The agreement between the experimental IC–ICP-MS results and the theoretical calculations was within 15% for most isotopes.