[1A08-12] Radiolysis, Corrosion 3

[1A10] Corrosion evaluation and mitigation in the PCV systems under the influence of α/β/γ radiolysis

(3) Effects of gaseous-phase radiolysis on water under irradiation

*Kuniki Hata¹, Atsushi Kimura², Tomonori Sato¹, Mitsumasa Taguchi², Chiaki Kato¹, Yutaka Watanabe³ (1. JAEA, 2. QST, 3. Tohoku Univ.)

Keywords:Radiolysis, Corrosion, Gamma ray, Nitrate ion, Hydrogen peroxide

In order to study effects of radiolysis of humid air on the corrosive environment for steel materials immersed in water in gas-liquid coexistence systems, gamma-radiolysis experiments were carried out, and concentrations of radiolytic products, such as hydrogen peroxide and nitrate ion, were measured. It was found that the concentrations of these products were dependent on the partial pressure of oxygen, and their production was sufficiently suppressed by deaeration. In this study, to estimate precisely the corrosive environment in primary containment vessels in TEPCO Fukushima Daiichi nuclear power stations, a radiolysis analysis method for gas-liquid coexistence systems was developed. The calculation results have showed a good similarity to the experimental results.