The application of Sr-spec resin in the analysis of 90Sr in effluent and environmental samples at KNPS

Abstract

Radiostrontium (90Sr and 89Sr) has been released to the environment by global fall-out following atmospheric nuclear explosions, by waste discharges and fall-out from the Chernobyl. 89Sr, with a half-life of 50.5 days, quickly decays to undetectable levels, while 90Sr is radiobiologically more important because of its longer half-life of 28.78 years, and because it behaves chemically similar to Ca, and accumulates in bones and teeth. Cost effective and relatively simple procedures for determination of radiostrontium are desirable. An accurate determination of radionuclides from various sources in the environment is essential for assessment of the potential hazards and suitable countermeasures both in case of accidents, authorised releases and routine surveillances. Reliable radiochemical separation and detection techniques are needed for accurate determination of alpha and beta emitters. Rapid analytical methods are needed in case of an accident for early decision-making. At the Koeberg Nuclear Power Station (KNPS), 90Sr analysis are performed on liquid effluent samples making use of the traditional fuming nitric acid method, and subsequent counting of particulate samples on an alpha/beta proportional counter. This method is often at times very time – consuming, and involves many precipitation steps. The use of fuming nitric acid is also very dangerous and could lead to severe personnel injuries in the event of an accident. This project focussed on the application of Sr-Spec resin in the analysis of 90Sr. This work presents the methods for 90Sr analysis for both effluent samples as well as environmental samples. This research also focussed on the calibration of the different radiometric instruments, which are the Liquid Scintillation Counter, the Alpha/Beta Counter as well as the Gamma Detector.