Curing method of compacted buffer blocks in high-level radioactive waste repository
In the high-level radioactive waste geological disposal repository,the canisters are usually surrounded by the buffer material in the form of compacted blocks,which is the key link to block nuclide migration.In order to ensure the engineering performance of the block,the surrounding environment should be controlled at all stages of manufacture,storage,transportation and installation to reduce the deterioration of buffer blocks.The long-term curing performance test of compacted Gao-miao-zi(GMZ)bentonite samples with different packaging methods,such as bare samples,film covering,film covering&sealing were carried out under the relative humidity of 0～100%.The test results indicate that the mass change ratio of the samples with water content 13%～15%was less than 1%when the environmental humidity is 80%～92%.Among them,the mass change ratio of the samples was not more than 0.3%under the relative humidity of 92%,which was the best curing environment.The method using film covering and sealed packaging can greatly expand the range of relative humidity.The mass change of the samples under different relative humidity were greatly reduced.When the relative humidity exceeds 57%,the mass change ratio of samples does not exceed 1%,and the minimum mass change ratio occurs under the relative humidity of 92%,which was only 0.032%.The research results of this paper can provide basic parameters and technical support for the long-term storage of meter-scale large buffer blocks.
国家科技期刊平台
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