The effect of boric acid on oxygen suppressing under γ-ray irradiation at 25°C

Simulation to understanding the reaction mechanism between boric acid that is being added into the PWR primary water and radio lysis products under y-rays irradiation at 25°C was done. Simulation has been done by using 'Facsimile' software based on continuing kinetic reaction. As inputs are set reactions that consist of 61 reactions, G-values under y-rays irradiation, dose rate of 10 and 104 Gy/s, initial concentration of oxygen for aeration (0.25M) and deaeration, and boric acid up to 1M. Outputs are series of concentration vs irradiation time. The putput data is being analysed by plotting them into graph by using 'Origin '. Validation was done by comparing the results with the previous work. From validation, it is know that the set reaction that is being used does not give any significant difference, then decided that the set reactions used is valid. The relation between concentration of boric acid and oxygen concentration logarithmically is linearly decrease. From the simulation, it can be understood either that the addition of H3B03 is not only for controlling the neutron reactivity but also give positive effect on suppressing the oxygen concentration that play role on corrosion process. (author)