Lee Keunyoung, Kim Jimin
Decommissioning Technology Research Division, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon, 34057, Republic of Korea.
Environmental Research Division, Daejeon Metropolitan City Institute of Health and Environment, 407, Daehak-ro, Yuseong-gu, Daejeon, 34142, Republic of Korea.
Environ Res. 2023 Mar 15;221:115309. doi: 10.1016/j.envres.2023.115309. Epub 2023 Jan 14.
To date, radiocesium (Cs) has been considered stable in the form of pollucite mineralized through high-temperature heat treatment. This study presented a possibility through experimental results that the entire medium exists as amorphous aluminosilicate at a relatively low temperature, but cesium is partially and preferentially converted from a composite adsorbent into pollucite. Cesium lowers the eutectic point within the system and initiates the nucleation of pollucite prior to other elements. We confirmed that the partial mineral phase of cesium showed the same chemical stability as when the entire medium was converted to pollucite. X-ray absorption spectroscopy provided direct evidence for this phenomenon; also, the stability results of radioactive cesium shown through a series of sintering experiments supported the conclusion. This method can be applied as a method to immobilize radioactive cesium under relatively mild temperature conditions of atmospheric pressure, while eliminating the problem of diffusion due to its volatilization.
迄今为止，放射性铯（Cs）被认为以经过高温热处理矿化的铯榴石形式存在时是稳定的。本研究通过实验结果表明，在相对较低的温度下，整个介质以无定形铝硅酸盐形式存在，但铯会部分且优先地从复合吸附剂转化为铯榴石。铯降低了体系内的共晶点，并在其他元素之前引发铯榴石的成核。我们证实，铯的部分矿物相表现出与整个介质转化为铯榴石时相同的化学稳定性。X射线吸收光谱为这一现象提供了直接证据；此外，通过一系列烧结实验得出的放射性铯的稳定性结果也支持了这一结论。该方法可作为一种在大气压相对温和的温度条件下固定放射性铯的方法，同时消除其因挥发导致的扩散问题。
