Pulse radiolysis study on aqueous solutions containing seawater components

Hata, Kuniki ; Hanawa, Satoshi ; Kasahara, Shigeki; Muroya, Yusa*; Katsumura, Yosuke*

Fukushima Daiichi Nuclear Power Units 1 - 3 experienced seawater injection into the reactor cores as an emergent measure to cool the reactors for a short period after the accident. As a result, structural materials in the reactors have been exposed to unexpected corrosion environment due to anions, such as Cl, in seawater. Furthermore, strong oxidants, such as ClO and ClO, through radiolysis of seawater by -rays would make the corrosion environment severer. Several studies on radiolysis of seawater at ambient temperature had been performed in the field of geological disposal of high level wastes, and amount of ClO and gas products had been evaluated. However, further examination is required on radiation induced reactions among seawater components to predict precisely the corrosion environment of the structural materials exposed to seawater. In the present study, the reactions of Cl derived radicals with Br were measured by pulse radiolysis. The production of mixed radical anion, BrCl, was observed in aqueous solutions containing 1 mol dm Cl with small amounts of Br. Model calculations are required to evaluate reaction rates of the reactions occurred in the complex solutions.