Measurement of hydrogen generating from radiolysis of highly active liquid waste and its quantitative evaluation

Yamamoto, Masahiko   ; Surugaya, Naoki ; Mori, Eito; Taguchi, Shigeo ; Sato, Soichi 

The H concentration generating from Highly Active Liquid Waste (HALW) of Tokai Reprocessing Plant is measured in a closed experimental system. The experimental results show that H concentration gradually increases at first and then approaches a steady-state due to the H consumption reaction by Pd ions. The highest H concentration is 1200 ppm (0.1%) when the solution temperature is at 23C. It is found that H generating from HALW is equilibrated one order of magnitude lower than the H combustion lower limit. Moreover, a model based on H generation from HALW by the radiolysis and H consumption reaction by Pd ions is proposed and applied to evaluate H concentration behavior in the gas phase. The calculated H concentrations from proposed model agreed well with the experimental values. It is demonstrated that the behavior of H generating from HALW can be evaluated quantitatively by applying the proposed model in this study.