Radioactive alkali fluoride salts are generated during the operation of molten salt reactors(MSRs) and reprocessing of their spent fuel, and appear in the formof fluidity granule, or powder. In order to prevent the ra...Radioactive alkali fluoride salts are generated during the operation of molten salt reactors(MSRs) and reprocessing of their spent fuel, and appear in the formof fluidity granule, or powder. In order to prevent the radionuclides from being released into the environment(especially, via exposure to water), it is necessary to develop a new technology for the temporary storage or final disposal of wastes containing radioactive fluorides. The immobilization of alkali fluoride wastes in phosphate glasses has been proposed. In this study, iron phosphate(IP) glasses and sodium aluminophosphate(NaAlP) glasses were evaluated for the immobilization of simulated radioactive fluoride wastes. IP and NaAlP glass matrixes were mixed with simulated wastes and reacted in air at temperatures in the range of 950–1200°C. A high waste loading was obtained in the experiment. The properties of the waste forms were characterized by X-ray diffraction and Raman spectroscopy. The latter indicated that IP glass contains less Q^2 without Q^3(2 and 3 represent the number of bridging oxygens on a PO_4 tetrahedron), and it is concluded that IP glass is more stable than NaAlP glass. Leaching tests were performed in deionized water by using the product consistency test A(PCT-A method), and the result shows that the leaching resistance of IP waste forms is better than that of NaAlP waste forms. This study demonstrates the potential of IP glass for the stabilization and immobilization of radioactive fluoride wastes from MSRs.展开更多
基金supported by the“Strategic Priority Research Program”of the Chinese Academy of Sciences(XD02005003)
文摘Radioactive alkali fluoride salts are generated during the operation of molten salt reactors(MSRs) and reprocessing of their spent fuel, and appear in the formof fluidity granule, or powder. In order to prevent the radionuclides from being released into the environment(especially, via exposure to water), it is necessary to develop a new technology for the temporary storage or final disposal of wastes containing radioactive fluorides. The immobilization of alkali fluoride wastes in phosphate glasses has been proposed. In this study, iron phosphate(IP) glasses and sodium aluminophosphate(NaAlP) glasses were evaluated for the immobilization of simulated radioactive fluoride wastes. IP and NaAlP glass matrixes were mixed with simulated wastes and reacted in air at temperatures in the range of 950–1200°C. A high waste loading was obtained in the experiment. The properties of the waste forms were characterized by X-ray diffraction and Raman spectroscopy. The latter indicated that IP glass contains less Q^2 without Q^3(2 and 3 represent the number of bridging oxygens on a PO_4 tetrahedron), and it is concluded that IP glass is more stable than NaAlP glass. Leaching tests were performed in deionized water by using the product consistency test A(PCT-A method), and the result shows that the leaching resistance of IP waste forms is better than that of NaAlP waste forms. This study demonstrates the potential of IP glass for the stabilization and immobilization of radioactive fluoride wastes from MSRs.
