Molten Hydroxide Trapping Process for Radioiodine

Trowbridge, L.D.

Oak Ridge National Laboratory

关键词: Thermodynamics;    Testing;    Iodine;    Hydroxides;    Iodides;   

DOI  :  10.2172/885865
RP-ID  :  ORNL/TM-2002/247
RP-ID  :  DE-AC05-00OR22725
RP-ID  :  885865

美国|英语

来源: UNT Digital Library

【 摘 要 】

A molten hydroxide trapping process has been considered for removing radioiodine species from off-gas streams whereby iodine is reacted directly with molten hydroxides such as NaOH or KOH. The resulting product is the corresponding iodide, which can be separated by simple cooling of the molten mixture to grow the iodide primary phase once the mixture reaches 70-80 mol% in the iodide component. Thermodynamic analysis indicates that such a chemical process is highly favorable. Experimental testing of the trapping process using molecular iodine showed trapping of up to 96% of the volatile iodine. The trapping efficiency was dependent on operational parameters such as temperature and gas-melt contact efficiency, and higher efficiencies are expected as the process is further developed. While an iodide phase could be effectively isolated by slow cooling of a molten iodide-hydroxide mixture, the persistent appearance of hydroxide indicated that an appreciable solubility of hydroxide occurred in the iodide phase.