A new method to analyze 242mAm in low-level radioactive waste based on extraction chromatography and β-ray spectrometry.

A new method for identifying (242m)Am in low-level radioactive waste (LLW) using β-ray spectrometry is proposed. First, (152)Eu, (241+242m+243)Am, and (244)Cm in a digested solution of simulated LLW were separated from the major components of the digested solution and Pu using a transuranium element resin (TRU resin). Next, Am and Cm were separated from Eu using a tetravalent actinide element resin (TEVA resin). A β-ray spectrum of the fraction containing Am and Cm was recorded and the contribution of (239)Np, which is a daughter nuclide of (243)Am, was subtracted to determine the radioactivity of (242m)Am. Also mutual separation of Am, Cm, and Eu was carried out using a tertiary pyridine resin to determine (242m)Am by analyzing the increase of (242)Cm in the Am fraction just after separation of Am from Cm, which is the traditional method. The isotope ratio of (242m)Am/(241)Am determined by β-ray spectrometry agreed with that obtained by analyzing the traditional method.