Equilibrium hydrogen concentration of Ni/NiO for exposure dose reduction

As a measure to reduce occupational exposure dose for workers at PWR nuclear power plants, it is important to reduce activation opportunity of corrosive products formed in the course of precipitating of elution substance from the component constituent material at the reactor core. Therefore, it is effective in exposure dose reduction to convert the chemical form of Ni, which was eluted from component material and attached to fuel clad surfaces, into NiO whose solubility is higher than that of Ni, by decreasing the concentration of dissolved hydrogen. Consequently, at Kyushu Electric Power, the equilibrium hydrogen concentration of Ni/NiO was confirmed by conducting at test where the hydrogen concentration changed under an actual-condition simulated environment. (author)