【摘要】 熔盐堆的运行和乏燃料的处理都不可避免地产生放射性氟化物废物.不同于传统堆产生的氧化物废物,这些氟化物废物大多以颗粒、粉末等分散形式存在,且具有腐蚀、化学稳定性差、易潮解等特点,所以其处理处置有赖于新技术新工艺的研究.本文分别选取铁磷酸盐（IP）玻璃和钠铝磷酸盐（NaAlP）玻璃固化模拟碱金属氟化物,并用X射线衍射分析、拉曼光谱和产品一致性检验方法对其结构和抗浸出性进行了测试.实验表明模拟氟化物在两种玻璃中的溶解度都很高（40 mol%以上）,NaAlP玻璃固化体中碱金属浸出率较高,这和其玻璃基材含有较多的Na有关,且拉曼光谱显示其结构中的磷氧四面体含有不稳定的Q³单元,而IP玻璃固化体对所有元素的浸出率都低于1 g m^-2 day^-1,故对固化熔盐堆产生的碱金属氟化盐有很大的潜在研究价值.更多还原

【Abstract】 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 Q² without Q³（2 and 3 represent the number of bridging oxygens on a PO₄ 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.更多还原