Activity Measurement of Iodine Fission Products in 2LiF-BeF2 Salt and Its Application in Redox Potential Surveillance for a Thorium Molten Salt Reactor

Junxia Geng; Zhongqi Zhao; Zhiqiang Cheng; Wenxin Li; Qiang Dou; Qingnuan Li

doi:10.1021/acs.inorgchem.2c00436

Activity Measurement of Iodine Fission Products in 2LiF-BeF₂ Salt and Its Application in Redox Potential Surveillance for a Thorium Molten Salt Reactor

Inorg Chem. 2022 May 16;61(19):7406-7413. doi: 10.1021/acs.inorgchem.2c00436. Epub 2022 May 4.

Authors

Junxia Geng^{1

2

3}, Zhongqi Zhao^{1

2

3}, Zhiqiang Cheng^{1

2

3}, Wenxin Li^{1

2}, Qiang Dou^{1

2

3}, Qingnuan Li^{1

2

3}

Affiliations

¹ Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
² Center for Excellence on TMSR Energy System, Chinese Academy of Sciences, Shanghai 201800, China.
³ University of Chinese Academy of Sciences, Beijing 100049, China.

PMID: 35508183
DOI: 10.1021/acs.inorgchem.2c00436

Abstract

The activities of ¹³¹I, ¹³²I, ¹³³I, and ¹³⁵I produced by neutron-induced fission of ²³⁵U in 2LiF-BeF₂ (FLiBe) eutectic salt and their dependence on the redox potential were studied. The dependence observed experimentally suggested that the activity ratio for ¹³¹I to ¹³²I could be used as an indicator of the redox potential for FLiBe salt. Relying on the selective adsorption of iodine ions on the activated silver probe by ion exchange, a novel method for activity distribution measurement of the iodine isotopes in FLiBe salt was founded. The method is simple, fast, and easy to operate and would be suitable particularly to in situ monitor the redox potential of a thorium molten salt reactor, where the redox potential should keep at a high level to avoid possible safety risk induced by ²³³Pa deposition in the reactor.