Preparation of solid water-equivalent radioactive standards

Abstract

Radioactive water standards prepared in Marinelli beakers can pose a problem due to potential leakage that can both compromise the standard and present a safety hazard. These difficulties can be circumvented by solidifying the standard such that it remains fundamentally water-equivalent. This paper describes a procedure that avoids the need to irradiate the standard. This entails the use of a small quantity of a super absorbent polymer, namely lightly cross linked polyacrylate. The polymer granules are simply added to the radioactive solution and thoroughly mixed to achieve homogeneity during the solidification process. Extensive measurements have confirmed the solid standard to be both homogeneous and water-equivalent.