After upgrading the Pakistan Research Reactor-1 from 5 MW (Th) to 10 MW (Th), increased inventory of (100)-Ag and Sb-124 in the waste stream demanded, some sort of treatment to bring the radioactivity levels within the disposal limits. A chemical treatment, making use of scavenging precipitation of the radionuclides with hydrous oxides of iron, was studied. Fe(II) hydrous oxide: coprecipitation, by, using green vitriol provided complete removal of silver activity band an acceptable decontamination factor (DF) for antimony. Coagulant doses and other parameters for decontamination of the bulk of the waste were studied and optimized. Various parameters and results of the process are presented. High DFs for silver and antimony radionuclides have been achieved.