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Rapid immobilization of cesium in radioactive molten salt waste via supercritical water hydrothermal synthesis
Author(s) -
Ran Maobiao,
Gou Xiaoliang,
Chen Shunzhang,
Shu Xiaoyan,
Liu Yi,
Zhang Shengdong,
Lu Xirui
Publication year - 2025
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.20511
Subject(s) - hydrothermal circulation , caesium , molten salt , radioactive waste , supercritical fluid , supercritical water oxidation , hydrothermal synthesis , salt (chemistry) , hydrothermal reaction , chemical engineering , materials science , chemistry , waste management , nuclear chemistry , inorganic chemistry , organic chemistry , engineering
Abstract To swiftly address Cs presence in radioactive molten salt waste, we utilized nonradioactive CsCl to simulate 137 CsCl. Through supercritical water hydrothermal synthesis with metakaolin, we converted it to pollucite and sodalite within 10 min. With Cs/Al and Si/Al mole ratios set at 0.4 and 2.0, respectively, the primary phase in the solidified form was predominantly pollucite, with CsCl solubility reaching 25.52 wt.%. All elements were uniformly distributed within the solidified form. Additionally, the supercritical water hydrothermal synthesis not only aided CsCl immobilization but also improved the chemical stability of the solidified form. The normalized leaching rate of Cs after 28 days is less than 4.03 × 10 −6 g m −2 day −1 , which is much lower than the existing solidification substrate. This investigation presents a fresh approach to the rapid disposal of radioactive molten salt waste.