Radiolysis of water containing ferrous and chloride ions

Hata, Kuniki ; Sato, Tomonori  ; Inoue, Hiroyuki*

To evaluate the integrity of structural materials in stagnant water in primary containment vessels (PCVs) of Fukushima Daiichi Nuclear Power Plants, corrosion prediction is important. Because of high-dose rate in the PCVs, oxidative molecules, such as HO or O, are generated from water radiolysis. For the corrosion prediction of materials in PCVs, the amounts of these molecules should be estimated. Stagnant water in the PCVs contains small amounts of impurities, such as anions from seawater or groundwater and metal cations derived from materials by corrosion. Some of these impurities show high reactivity with radiolytic species and would affect the production behavior of the oxidative molecules. In this study, the influence of Cl on radiolysis of solutions, which contains small amount of Fe, was investigated by radiolysis simulation. Acidification of the solutions due to reactions of Fe under irradiation enhanced the reaction of Cl with radiolytic species, which resulted in the increase in the amounts of HO.