Removal of ruthenium from high level radioactive liquid waste generated during reprocessing of spent fuel

High level acidic liquid wastes (HLW) are generated during reprocessing of spent fuel. It contains minor actinides, corrosion products, activation products and short lived and long lived fission products. Sodium borosilicate glass has been adopted as a solid matrix for immobilisation of HLW worldwide. Radio ruthenium (Ru) is the most troublesome fission product. Major part of Ru volatilises as RuO4 during vitrification. Its subsequent decomposition to RuO2 leads to plating out on cooler surfaces in the off gas lines resulting in hot spots. The problems associated with Ru volatilization could be aggravated in case of short cooled fuel having higher Ru activity. The present work involves the development of a process for the separation of Ru from HLW stream by volatilization using KMnO4 (Potassium permanganate) and O3 (Ozone) as oxidizing agent and its subsequent trapping on adsorbent material PEEK pellets (Poly Ether Ether Ketone)