Formation of H2 and O2 in Radiolysis of Water Sorbed on PuO2

Samples of PuO2 containing sorbed water, when stored at room temperature, release hydrogen and oxygen into the gas phase. At a given content of water, the rates of formation of H2 and O2 are in direct proportion to the dose rate of plutonium radiation. With increasing concentration of water from 0.3 to 3% the rates of formation of H2 and O2 increase by a factor of 60-100, which is caused by increase in both the energy of α-radiation absorbed by water and radiation-chemical yields of formation of H2 and O2. The radiation-chemical yields of formation of oxygen and hydrogen at the 0.3% content of sorbed water are lower, and at the water content exceeding 1%, higher than the yields of these products in radiolysis of “free” water. On storage of powder-like and pelletized samples of PuO2 of power reactor origin with a 3% water content for 150-200 days, the stationary concentration of hydrogen approximately corresponding to the initial concentration of sorbed water is established.