Study On Leaching Behavior Of Borosilicate Glass

It is very important to dispose high level radioactive waste safely and efficiently, which is the guarantee of stabilized and sustainable development of nuclear industry. Nowadays, a widely adopted reliable way of disposal is "glass solidification geological disposal". However, during the geological disposal of the high-level radioactive waste glass forms, it will contact and react with the groundwater, result in the leaching of radioactive nuclides, enter into the biosphere by groundwater circulation process, cause harmnesses to human environment. Therefore, it is crucial to study the leaching behavior under different conditions, which is also very important for effective evaluation glass forms safety in geological disposal environment.Due to the decay of radioactive nuclides, the temperature of waste glass will be raised, and it will suffer long term radiation. Therefore, it is very important to study the effects of temperature and radiation on the leaching behavior of waste glass. However, as far as we know, it is the first time to study electron irradiation effects on the leaching rate.Two kinds of borosilicate glass were studied under different leaching conditions (time, temperature). And also the effects of electron irradiation on the leaching rate were investigated. The doses were1×107,1×108and1×109Gy, respectively. Five leaching times(1,3,7,14and28days) were used in our experiment. The leaching temperatures were20,40,70and90℃, respectively. For self-made borosilicate glass, the experimental results show that:1) The leaching rate was less than lg/m2·d within28days and decreased with increase of leaching time.2) As increased of temperature, the leaching rate obviously increased. It’s low at20-40℃,and about an order of magnitude lower than that at90℃3) The leaching rate increases with the electron irradiation dose. but there was no change on the order of magnitude within the absorbed dose of109Gy.Compared with self-made borosilicate glass, the leaching rate of special glass is lower under the same leaching conditions. No obvious change after electron irradiation was observed, indicating higher radiation resistance of this special glass.