Abstract
Cement in a repository for radioactive waste disposal will produce a high pH in water within the repository. The pH is anticipated to decrease with time as water flows through the repository and leaches out soluble ions. This process has been simulated in accelerated laboratory experiments using sulphate resisting Portland cement and demineralised water. The evolution of pH and the aqueous concentrations of Ca, Si and Al have been monitored during leaching and compared with predictions based on a simplified model of cement chemistry and equilibrium data for the CaO-SiO/sub 2/-H/sub 2/O system. Reasonable qualitative agreement between the predictions and the experiments was found. Residual detailed discrepancies which were evident were caused by complete equilibrium not being attained in the leaching experiments. The experiments support the view that cement should maintain a pH above about 10.5 for timescales of the order of a million years under the low water flow rates expected at a repository. (author).
Citation Formats
Atkinson, A, Everitt, N M, and Guppy, R.
Evolution of pH in a radwaste repository: experimental simulation of cement leaching.
United Kingdom: N. p.,
1987.
Web.
Atkinson, A, Everitt, N M, & Guppy, R.
Evolution of pH in a radwaste repository: experimental simulation of cement leaching.
United Kingdom.
Atkinson, A, Everitt, N M, and Guppy, R.
1987.
"Evolution of pH in a radwaste repository: experimental simulation of cement leaching."
United Kingdom.
@misc{etde_5534690,
title = {Evolution of pH in a radwaste repository: experimental simulation of cement leaching}
author = {Atkinson, A, Everitt, N M, and Guppy, R}
abstractNote = {Cement in a repository for radioactive waste disposal will produce a high pH in water within the repository. The pH is anticipated to decrease with time as water flows through the repository and leaches out soluble ions. This process has been simulated in accelerated laboratory experiments using sulphate resisting Portland cement and demineralised water. The evolution of pH and the aqueous concentrations of Ca, Si and Al have been monitored during leaching and compared with predictions based on a simplified model of cement chemistry and equilibrium data for the CaO-SiO/sub 2/-H/sub 2/O system. Reasonable qualitative agreement between the predictions and the experiments was found. Residual detailed discrepancies which were evident were caused by complete equilibrium not being attained in the leaching experiments. The experiments support the view that cement should maintain a pH above about 10.5 for timescales of the order of a million years under the low water flow rates expected at a repository. (author).}
place = {United Kingdom}
year = {1987}
month = {Mar}
}
title = {Evolution of pH in a radwaste repository: experimental simulation of cement leaching}
author = {Atkinson, A, Everitt, N M, and Guppy, R}
abstractNote = {Cement in a repository for radioactive waste disposal will produce a high pH in water within the repository. The pH is anticipated to decrease with time as water flows through the repository and leaches out soluble ions. This process has been simulated in accelerated laboratory experiments using sulphate resisting Portland cement and demineralised water. The evolution of pH and the aqueous concentrations of Ca, Si and Al have been monitored during leaching and compared with predictions based on a simplified model of cement chemistry and equilibrium data for the CaO-SiO/sub 2/-H/sub 2/O system. Reasonable qualitative agreement between the predictions and the experiments was found. Residual detailed discrepancies which were evident were caused by complete equilibrium not being attained in the leaching experiments. The experiments support the view that cement should maintain a pH above about 10.5 for timescales of the order of a million years under the low water flow rates expected at a repository. (author).}
place = {United Kingdom}
year = {1987}
month = {Mar}
}