Gas diffusion in EBS materials: Final report

Research output: Report/bookER - External reportpeer-review

Institutes & Expert groups

  • NIRAS/ONDRAF

Documents & links

Documents

Abstract

In many countries, the preferred option for the long term management of high- and intermediate level radioactive waste and spent fuel is final disposal in a geological repository. Generation of gas will be unavoidable in this geological repository. In order to make a correct balance between gas generation and dissipation by diffusion, knowledge of the diffusion coefficients of gases in the host rock and the engineered barriers is essential. Diffusion coefficients for the Boom Clay host rock are available, but diffusion coefficients for gases in the engineered concrete barriers are still lacking. Therefore, diffusion experiments with dissolved gases were performed on two concrete based barrier materials considered in the current Belgian disposal concept. Experiments were performed by using the double through-diffusion technique for dissolved gases which was developed in 2008 by SCK CEN. Diffusion measurements were performed with four gases including helium, neon, methane and ethane. Information on the microstructure of the materials (e.g. pore size distribution) was obtained by combining N2-adsorption, mercury intrusion porosimetry (MIP), scanning electron microscopy (SEM) and water sorptivity measurements. A comparison was made with data obtained from cement-based samples (intact and degraded), and the validity of existing predictive models was investigated.

Details

Original languageEnglish
PublisherSCK CEN
Number of pages28
Publication statusPublished - 22 Feb 2022

Publication series

NameSCK CEN Reports
PublisherSCK CEN
No.ER-1076

Keywords

  • Diffusion, Gas, Engineered barrier, Concrete

ID: 7410805