Efficacy of chlorinated cobaltdicarbollide in a modified diluent, 20% nitrobenzene in xylene was tested for the extraction
and recovery of Cs from simulated high-level waste (HLW) solutions generated from PHWR-fuel reprocessing. Concentration of
the reagent, composition of the diluent, numbers of contacts, the nature of stripping agents are some of the parameters optimized
for the complete removal of Cs from such waste solutions. The above solvent extraction procedure can be applied to genuine
HLW solutions for effective reduction of the dose due to Cs so that HLW can be handled in fume hoods for its characterization.