Nuclear Techniques ›› 2016, Vol. 39 ›› Issue (2): 20602-020602.doi: 10.11889/j.0253-3219.2016.hjs.39.020602

• NUCLEAR ENERGY SCIENCE AND ENGINEERING • Previous Articles     Next Articles

Evaporation and separation of CsF in FLiNaK molten salt

JIA Yunpeng1,2, WANG Zihao1, GENG Junxia1, YANG Yang1, DOU Qiang1, CONG Haixia1, LI Qingnuan1, FU Haiying1   

  1. 1 Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Jiading Campus, Shanghai 201800, China;
    2 University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2015-09-18 Revised:2016-01-04 Online:2016-02-10 Published:2016-02-17
  • Supported by:

    Supported by the Strategic Priority Program of the Chinese Academy of Sciences (No.XDA02030000)

Abstract:

Background: The removal of CsF, a major fission product in molten salt reactor, on a regular basis is helpful for the improvement of neutron economy of the reactor. Purpose: This study aims to investigate the evaporation behavior of CsF under different experimental conditions in FLiNaK molten salt. Methods: Two different evaporation methods, namely vacuum distillation and reductive evaporation by metal lithium, were employed in this work. Results: The results from the experiments of vacuum distillation at 5 Pa revealed a linear correlation between evaporated mass of CsF and evaporation temperature. At 780℃, the CsF concentration in molten salt decreased from 1% to 0.14% upon distillation with a separation rate of 86% despite the loss of 9.5% of the carrier salt. Reductive evaporation by metal lithium was carried out at 700℃ and 1.01×105 Pa. The amount of evaporated CsF increased with the increase of lithium added into the molten salt. The separation rate was 91% at a molar ratio of lithium to CsF of 120. Conclusion: Fundamental data are provided to understand the evaporation behaviors of CsF in fluoride molten salt, which could further benefit the establishment of efficient separation technique for CsF removal from spent fuel.

Key words: CsF, FLiNaK, Evaporation, Reductive

CLC Number: 

  • TL426