Medium-Temperature Phosphate Glass Composite Material as a Matrix for the Immobilization of High-Level Waste Containing Volatile Radionuclides

The search for matrices and technological solutions for the reliable immobilization of volatile radionuclides and high-level waste (HLW) components is an actual radiochemical problem. Methods of obtaining of sodium alumino-iron phosphate (NAFP) and iron phosphate (FP) glass composite materials synthesized at temperatures of 450-750 degrees C, their structure and hydrolytic stability were investigated in this paper. The structure of the samples was studied by XRD and SEM-EDS. It was shown that, in the case of FP materials, the phase composition varies depending on the synthesis temperature, while NAFP materials have a complex multiphase composition at all crystallization temperatures. It has been established that the samples of the obtained glass composite materials have a high hydrolytic stability. At the same time, FP material obtained at 650 degrees C are the most stable, which makes this medium-temperature method of synthesis promising for the immobilization of volatile HLW components.

Automated summary

The search for matrices and technological solutions for the reliable immobilization of volatile radionuclides and high-level waste components is an important radiochemical problem. This study investigated the preparation methods, structure, and hydrolytic stability of sodium alumino-iron phosphate (NAFP) and iron phosphate (FP) glass composite materials synthesized at temperatures of 450-750 degrees C. XRD and SEM-EDS techniques were used to study the structure of the samples. It was found that the phase composition of FP materials varied depending on the synthesis temperature, while NAFP materials had a complex multiphase composition at all crystallization temperatures. The obtained glass composite materials showed high hydrolytic stability, with FP materials synthesized at 650 degrees C being the most stable, making this medium-temperature synthesis method promising for the immobilization of volatile high-level waste components.