Determination of fission products and actinides in spent nuclear fuels by isotope dilution ion chromatography inductively coupled plasma mass spectrometry

An Elan 5000 inductively coupled plasma mass spectrometry (ICP-MS) instrument was modified for its installation in a glove-box for the analysis of radioactive materials. An ion chromatographic system was coupled to the ICP-MS instrument. The chromatographic pump was set outside the box while the injection valve and separation column were installed inside the box coupled directly to the cross-flow nebulizer. Performance characteristics of the modified ICP-MS system were evaluated regarding long-term stability, optimum plasma and ion lens conditions, sensitivity and detection limits, polyatomic ions, mass discrimination, detector dead time and uranium matrix interferences. Chromatographic methods were developed for the separation of fission Cs from Ba, for the lanthanide elements (La to Gd) and for the actinides (U to Cm) in order to eliminate isobaric interferences. Isotope dilution analysis was applied for the determination of selected fission products and actinides in spent nuclear fuels after ion chromatographic separation.