Understanding the recovery of Ruthenium from acidic feeds by oxidative solvent extraction studies

Abstract

Abstract Ruthenium (106Ru), a notorious fission product in nuclear reprocessing cycle, which gets partitioned at each step needs to be recovered. The recovery of Ru from acidic high level waste (HLW) is of great importance to the nuclear fuel cycle. Quantitative recovery of Ru was achieved from acidic feeds using oxidative trapping mechanism strategy where NaIO4 was used as an oxidant to convert different species of Ru in acidic phase to RuO4 while n-dodecane was used as trapping agent for RuO4. Stripping was attempted using NaOH and NaClO mixture. Attempt was made to optimize various parameters for 103Ru extraction and stripping. 103Ru tracer spiked simulated high level waste was used to understand the 103Ru behaviour in actual waste. The composition of stripping solution (alkaline hypochlorite) was also optimized to have >95% Ru into the aqueous phase in ca. 180 min.