Treatment of¹⁰⁶Ru Present In Intermediate Level Radioactive Liquid Waste With Nickel Sulphide

Abstract

Abstract 106Ru is one of the major radionuclides of concern in the aqueous radioactive waste generated during the reprocessing of the spent fuel. Intermediate level radioactive liquid waste (ILW) stream is generated during reprocessing of spent fuel and is neutralised with alkali to enable it to be stored in carbon steel tank. The waste is initially treated for 137Cs recovery using a specific resorcinol formaldehyde (RF) ion exchange resin. The effluent stream from the ion exchange treatment process has significant activity due to 106Ru. The present paper deals with a chemical treatment study for removal of 106Ru in the effluent using sulphides of cobalt and nickel. The decontamination factor of 250 obtained using NiS (at 2500 ppm concentration of Ni2+) is distinctly better than that obtained using CoS (at 7200 ppm concentration of Co2+).