[en] The aqueous solutions of oxalic acid and formic acid radiolysis under gamma rays was studied. The kinetics change of the hydrogen peroxide concentration, the COD and pH change, and the formation of gaseous products in their aqueous solutions depending on the absorbed dose were studied. In both solutions the acidity decreases, and this is due to the radiolytic decomposition of acids in the solution. From the initial part of kinetic curves, the radiation-chemical yields for CO₂ were calculated. The accumulation of gaseous products causes a risk for the secure storage of liquid radioactive waste. But with increasing partial pressure of carbon dioxide, its solubility rises in water and when the pH≥4, the carbon dioxide is in equilibrium with carbonic acid in the solution