137Cs稳定晶格固化与其高温挥发的矛盾是含Cs核废料固化要解决的关键问题。本项目结合铯榴石（CsAlSi2O6）稳定性、高Cs包容量、137Cs晶格固化等优势和地聚合物固化体低温合成、工艺简单等特点，提出以载Cs地聚合物凝胶为前驱体，温和水热条件下（T≤220℃，P≤1.2MPa），在凝胶中原位生长微晶铯榴石，得到由微晶铯榴石晶格固化相和地聚合物凝胶相组成的铯榴石型微晶地聚合物固化体。重点研究微晶铯榴石低温原位生长机理及固化体组成和结构调控机制，揭示Cs在固化体中的存在状态和行为；同时探索137Cs的β衰变产物Ba离子等对固化体结构和性能影响。铯榴石型微晶地聚合物的制备工艺简单、条件温和，在实现137Cs的铯榴石晶格固化同时避免了其高温挥发，将为含Cs核废料固化基材遴选、固化工艺和最终处置方案的确定提供理论基础，具有重要的工程应用价值。

Contradiction between crystal lattice immobilization and volatization of cesium-137 at high sintering temperature is the key scientific problem in preparing nuclear waste forms. Based on the stability, high capability, crystal lattice immobilization of pollucite and the low temperature, simple process of Geopolymer forms, the proposed project put forward the in-situ growth of microcrystalline pollucite in gel by using cesium loaded Geopolymer as precursor under moderate hydrothermal conditions (T≤220℃, P≤1.2MPa), and the cesium-137 will be eventually positioned in pollucite crystal lattice. From this, the microcrystalline Geopolymer with pollucite-type Structure (MGP) waste form will be attained. The growth mechanism of microcrystalline pollucite in gel at low temperature and the structure and performance regulation mechanism of MGP will be researched, which will clarify the behavior and occurrence of cesium-137. In addition, effect of the decay product (Ba) of cesium-137 in MGP will also be researched. The moderate hydrothermal conditions and simple process will be considered from the preparing of cesium loaded Geopolymer to the formation of MGP, which will avoid the volatization cesium-137 and realize the crystal lattice immobilization simultaneously. It is expected that the proposed project would provide the beneficial references for waste form matrix, immobilization process and disposal of nuclear waste containing cesium-137.