DURABILITY OF SOME GAMMA-IRRADIATED ALKALI BORATE GLASSES

Dissolution of glass coupons in acid solution with the general composi tion 80 B2O3, 10 Na2O and 10 RO (divalent oxide) has been monitored wi th and without gamma-irradiation. The increase in glass solubility upo n gamma-ray irradiation is interpreted in relation to the expected rad iation damage in the glass matrix, which is possibly due to the compet ition between the intrinsic defects and the induced defects incurred b y irradiation. The decrease in glass durability at 100-degrees-C is re lated to the increase in the activation energy of the corrosion proces s which leads to the dissolution of B from the glass and the formation of a surface layer. Moreover, the role of alkaline earth metal is als o discussed according to the influence of the size and activity coeffi cient of cations, as well as its ability to be adsorbed on the glass s urface. Also the amount of Na released from the leaching solution for the different ternary glasses was estimated and evaluated.