Rapid Immobilization of Simulated Radioactive Soil Waste Using Self-Propagating Synthesized Gd₂Ti₂O₇ Pyrochlore Matrix

Jiali Xue; Kuibao Zhang; Zongsheng He; Wenwen Zhao; Weiwei Li; Dayan Xie; Baozhu Luo; Kai Xu; Haibin Zhang

doi:10.3390/ma12071163

Rapid Immobilization of Simulated Radioactive Soil Waste Using Self-Propagating Synthesized Gd₂Ti₂O₇ Pyrochlore Matrix

Materials (Basel). 2019 Apr 10;12(7):1163. doi: 10.3390/ma12071163.

Authors

Jiali Xue¹, Kuibao Zhang^{2

3}, Zongsheng He⁴, Wenwen Zhao⁵, Weiwei Li⁶, Dayan Xie⁷, Baozhu Luo⁸, Kai Xu⁹, Haibin Zhang¹⁰

Affiliations

¹ State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China. xuejiali0304@163.com.
² State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China. zhangkuibao@swust.edu.cn.
³ Sichuan Civil-Military Integration Institute, Mianyang 621010, China. zhangkuibao@swust.edu.cn.
⁴ State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China. hezongsheng@swust.edu.cn.
⁵ State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China. zhaowenwen@swust.du.cn.
⁶ State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China. liweiwei@swust.du.cn.
⁷ State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China. xiedayan@swust.edu.cn.
⁸ State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China. luobaozhu@swust.edu.cn.
⁹ State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China. kaixu@whut.edu.cn.
¹⁰ Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China. hbzhang@caep.cn.

Abstract

A rapid and effective method is necessary in the disposal of severely radioactive contaminated soil waste. Simulated Ce-bearing radioactive soil waste was immobilized by self-propagating high-temperature synthesis (SHS) within 5 min in this study. The main work includes the rapid synthesis of soil waste forms, the analysis of phase composition, microstructure and chemical durability. These results show that the simulated nuclide Ce was successfully immobilized into the pyrochlore-rich waste matrice, whose main phases are SiO₂, pyrochlore (Gd₂Ti₂O₇) and Cu. The normalized leaching rates of Si and Na on the 42nd day are 1.86 × 10^-3 and 1.63 × 10^-2 g·m^-2·d^-1, respectively. And the normalized leaching rate of Ce also remains at low level (10^-5-10^-6 g·m^-2·d^-1) within 42 days.

Keywords: CeO2; Gd2Ti2O7 pyrochlore; Immobilization; Radioactive soil waste; SHS.

Abstract

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