Formation of AgI/Ag_3PO_4 solid solution on alumina for enhancing radioactive iodine adsorption at high temperatures  

作　　者：Xin Wang Tai-Wei Chu 

机构地区：[1]Beijing National Laboratory for Molecular Sciences,Radiochemistry and Radiation Chemistry Key Laboratory of Fundamental Science, College of Chemistry and Molecular Engineering, Peking University

出　　处：《Nuclear Science and Techniques》2018年第5期25-35,共11页核技术（英文）

基　　金：supported by the National Natural Science Foundation of China(Nos.11575010 and 21201013)

摘　　要：Radioiodine-131 is one of the pernicious radionuclides released during nuclear accidents, as its radioactivity can potentially affect public health and safety.To prevent radioiodine-131 from being released into the environment, the use of adsorbents that are highly efficient at high temperatures is significantly important. The radioactive gas from the nuclear core in an accident, such as the Fukushima nuclear accident, is usually released occurs under high-temperature conditions. Therefore, in this study, a 10 wt% silver phosphate-loaded alumina(Ag_3 PO_4/Al_2 O_3) adsorbent was prepared. Further, its performance toward radioiodine adsorption was tested at high temperatures up to 750 0 C, using Al_2 O_3 and traditional 10 wt% Ag/Al_2 O_3 adsorbent as controls. The results of the iodine adsorption test indicated that the 10 wt% Ag_3 PO_4/Al_2 O_3 adsorbent showed a higher decontamination factor than did the 10 wt% Ag/Al_2 O_3 adsorbent by two orders of magnitude at 650 and 750℃. Results of the iodine desorption test revealed that the new adsorbent could be effectively used at 750 ℃. The characteristic powder X-ray diffraction, nitrogen adsorption-desorption isotherm,X-ray photoelectron spectroscopy, and thermogravimetric analysis-differential scanning calorimetry data indicated that the enhanced adsorption ability at high temperatures was attributed to the formation of a solid solution between silver iodide and Ag_3 PO_4.Radioiodine-131 is one of the pernicious radionuclides released during nuclear accidents, as its radioactivity can potentially affect public health and safety.To prevent radioiodine-131 from being released into the environment, the use of adsorbents that are highly efficient at high temperatures is significantly important. The radioactive gas from the nuclear core in an accident, such as the Fukushima nuclear accident, is usually released occurs under high-temperature conditions. Therefore, in this study, a 10 wt% silver phosphate-loaded alumina(Ag_3 PO_4/Al_2 O_3) adsorbent was prepared. Further, its performance toward radioiodine adsorption was tested at high temperatures up to 750 0 C, using Al_2 O_3 and traditional 10 wt% Ag/Al_2 O_3 adsorbent as controls. The results of the iodine adsorption test indicated that the 10 wt% Ag_3 PO_4/Al_2 O_3 adsorbent showed a higher decontamination factor than did the 10 wt% Ag/Al_2 O_3 adsorbent by two orders of magnitude at 650 and 750℃. Results of the iodine desorption test revealed that the new adsorbent could be effectively used at 750 ℃. The characteristic powder X-ray diffraction, nitrogen adsorption-desorption isotherm,X-ray photoelectron spectroscopy, and thermogravimetric analysis-differential scanning calorimetry data indicated that the enhanced adsorption ability at high temperatures was attributed to the formation of a solid solution between silver iodide and Ag_3 PO_4.

关 键 词：Nuclear ACCIDENT RADIOIODINE Solid ADSORBENT High-temperature ADSORPTION 

分 类 号：TL[核科学技术]