高放废液（HLLW）中重要裂变核素铯（Cs）的放射性强度大、发热量高，会对高放废液的固化处理以及地质处置产生显著影响。本项目以HLLW中核素Cs的高效分离与安全处置为目标，采用孔内结晶技术，将杂多酸盐无机离子交换剂磷钼酸铵（AMP）负载到多孔性SiO2中，合成一种对Cs具有优良吸附性能且易于固化的新型无机盐类复合吸附材料，利用SiO2粒径小、孔径大和孔隙率高的特征，提高复合材料对Cs离子的吸附速度和容量，从HLLW中选择性分离Cs；然后以沸石为固化基材将吸附Cs后的复合材料直接煅烧成稳定的固化体进行处置。探讨吸附/固化机理，评价吸附材料的辐照和化学稳定性，以建立从HLLW中Cs的高效分离-固化流程。研究成果不仅可以丰富Cs的分离和固化理论，同时也为新型分离材料的开发提供一条新思路，为我国的放射性废物处理处置以及潜在资源的再利用提供重要的理论和技术支撑。

The nuclide Cs, contained in high-level liquid waste (HLLW), exhibits very high radioactivity and heat generation. Therefore, the selective separation and immobilization of Cs is an important subject for establishing an advanced nuclear fuel cycle. In this study, we attempt to load ammonium molybdophospahte (AMP) into the porous silica (SiO2) using crystallization method to synthesize a hybrid adsorbent for selective separation of Cs from HLLW and direct calcination of used absorbent as a stable ceramic solid form. The present work deals with the synthesis of AMP loaded silica, characterization, chemical stability, adsorption properties and column chromatographic separation. The thermodynamic and kinetic methods are used to evaluate the adsorption mechanism. Furthermore, the ceramic products immobilizing Cs is prepared and its solidification properties are investigated. Finally, the promising immobilization conditions are discussed. The results of this study are useful for the exploration of new materials for separation and solidification of Cs, and provide a scientific and technological support for the treatment and reutilization of nuclear wastes.