Determination of uranium concentration and burn-up of irradiated reactor fuel in contaminated areas in Belarus using uranium isotopic ratios in soil samples

Abstract

Summary An analytical method is described for the estimation of uranium concentrations, of 235U/238U and 236U/238U isotope ratios and burn-up of irradiated reactor uranium in contaminated soil samples by inductively coupled plasma mass spectrometry. Experimental results obtained at 12 sampling sites situated on northern and western radioactive fallout tails 4 to 53 km distant from Chernobyl nuclear power plant (NPP) are presented. Concentrations of irradiated uranium in the upper 0–10 cm soil layers at the investigated sampling sites varied from 2.1 × 10−9 g/g to 2.0 × 10−6 g/g depending mainly on the distance from Chernobyl NPP. A slight variation of the degree of burn-up of spent reactor uranium was revealed by analyzing 235U/238U and 236U/238U isotope ratios and the average value amounted to 9.4 ± 0.3 MWd/(kg U).