Effect of dimension of specimen on amounts of Cesium-137, Strontium-90 and Cobalt-60 leached from matrix of hardened cement grout

Abstract

The relationship between the fraction leached and the ratio of surface area and volume (S/V) of a specimen has been studied in order to evaluate the safety of a cement composite for disposal. The leaching fraction of radionuclides was measured for the different S/V ratios. In a case of either137Cs,90Sr or60Co, the amount leached is directly proportional to the S/V ratio. It is in harmony with the empirical formula proposed here, which can be derived from the diffusion equation with a semi-infinite plane source model. The amounts of137Cs,90Sr and60Co leached from a cement composite of 200 l drum size are estimated on the basis of the above relation, referring to the data obtained with a cylindrical shape specimen (4.5cm in dia. and 4.4cm high). © 1978 Taylor & Francis Group, LLC.