Effect of Gamma and Alpha Irradiation on the Corrosion of the French Borosilicate Glass SON 68

摘要

Corrosion experiments with the French borosilicate glass SON 68 were conducted under gamma (6 Co source) and alpha (cyclotron) irradiation conditions. Static tests with glass powder were conducted at 90°C under saturation conditions with synthetic solutions rich in Si, B and Na. The initial pH was 9.8 and the SA/V was 3970 m~(-1). For gamma irradiation tests with the highest dose (～58000 Gy) the pH decreased by almost a unit, which lasted for two weeks. The ion-exchange between glass and solution was enhanced as evidenced by the increase of the Li-normalized mass loss within 93 days. The measured H2O2 concentration in the experiment with the glass was as high as 1.51 10~(-5) M. The alpha irradiation tests with a total dose of 1800 Gy did not affect the solution pH and therefore the leaching rate of the glass remained similar to that in the blank experiment after 59 days. However, the measured H_2O_2 concentration was as high as 2.32 10~(-5) M. This work indicates that high irradiation doses may enhance the ion-exchange process due to the pH decrease.