Chemical Behavior of Radioiodine in Boiling Water Reactor Systems II: Effects of Hydrogen Water Chemistry

The investigation of the chemistry and steam transport behavior of radioiodine in boiling water reactors has been extended to four more reactors during fullscale hydrogen water chemistry (HWC) tests. Under the reducing coolant chemistry environment, most of the radioiodine was found in the iodide (I^-) form. The iodine steam carryover was found to increase in varying degree under HWC conditions in two reactors and was practically unchanged in the other two reactors. The variations in radioiodine chemical forms and steam carryover are discussed in terms of radiolytic reactions, and the effect of copper ions in the reactor water is qualitatively evaluated. The effect of HWC on radioiodine transport is not significant.