Comprehensive process flowsheet demonstration for the recovery of valuable radionuclides and partitioning of active–inactive constituents of high-level radioactive liquid waste: part – I

Le résumé fourni par la source

The High-level Radioactive Liquid Waste (HLW)-Advanced Treatment (HAT) process, designed and demonstrated at the Waste Immobilisation Plant in Kalpakkam, India, focuses on recovering valuable radionuclides and separating radioactive from inactive constituents in HLW. The process has been demonstrated with simulated, diluted, and actual waste solutions. The HAT uses various extractants like tri-butyl-phosphate (TBP), 1,3-dioctyloxycalixarene-crown-6 ;(CC6), di-tert-butyl cyclohexano-18-crown-6 (DTBCH18C6), tetra-2-ethylhexyl-diglycolamide (TEHDGA), bis-triazinyl-pyridine (BTP), and nano-titania impregnated epichlorohydrin crosslinked chitosan (TA-Cts-Eip) beads. The process, using 0.01 M HNO3, efficiently recovers uranium, cesium (Cs-137, Cs-134), strontium (Sr-90), rare earth elements, americium (Am-241), curium (Cm-244), and antimony (Sb-125). High separation efficiency, exceeding 99.99% for Am-241 and Cs-137, and 99.89% for Sr-90, has been achieved using this process. Decontamination factors were 3.92 × 105 for gross alpha and 3.83 × 107 for gross beta. Exotic solvents were recovered after carbonate wash, with low and acceptable residual radioactivity. The results indicate that the HAT process suits industrial-scale applications, maximizing radionuclide recovery, reducing waste, and ensuring safe management. Additionally, the thermal stability of the extractant and HAT solvents was briefly studied.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.