The Behavior of Radiolytically Produced Hydrogen in a High-Level Liquid Waste Tank of a Reprocessing Plant: Hydrogen Concentration Under Gamma Irradiation of the Simulated Solution

Simulated high-level liquid waste was irradiated by ⁶⁰Co gamma radiation, and changes in the gas-phase concentrations of the products H₂, O₂, and NO_x that accumulated in the absence of sweeping air were measured. The H₂ concentration reached a steady-state value of much less than 4% in line with the value predicted from the previously derived mathematical expression. The simulated dissolver solution was also irradiated, and another steady-state H₂ concentration of much less than 4% was obtained in accordance with the corresponding predicted value. These experimental results lend strong support for the applicability of a mathematical expression in predicting the H₂ concentration in a tank in the case of a sweeping-air function loss.