Determination of 89Sr and 90Sr from low- and intermediate-level radioactive liquid waste

This paper reports on the method, results, and experiences of the Sr-89 and Sr-90 analysis performed on low-and intermediate-level radioactive liquid waste samples from the Paks Nuclear Power Plant. The analysis is based on a combined separation method, which results in the separation and detection of radiostrontium (Sr-89 and Sr-90) and of Y-90. After the suitable pretreatment of the samples, radiostrontium is concentrated using the Sr-Spec(R) (EIChroM Industries, Darien, IL, 60561 USA) chromatographic column. The eluted radiostrontium is precipitated in a thin layer and its activity measured by a low-background, gamma-ray-compensated, alpha-beta detector. The chemical yield is determined by atomic emission spectroscopy. The Y-90 activity of the samples is also measured by the procedure described elsewhere. This measurement is based on the selective adsorbing property of the yttrium-ammonium-oxalate and the yttrium-oxalate double salt mixture of yttrium. Under the proper conditions ( pH, oxalate anion activity, mass ratio of the salts) the quantitative yield of Y-90 can be achieved, as determined by using the Y-88 inner standard. As a result, the radioactive concentration of Sr-90 in the samples could be calculated. It was concluded that Sr-89 was not present in the samples because of the relatively long tin years) storage life of these samples. However, this combined method can be easily adapted to matrices sampled at nuclear test sites.