The overall aim of Long-term Cement Studies (LCS) is to increase understanding of the cement leachate interaction effects in the repository near-field and geosphere so that modelling can make confident, robust safety-relevant assessments of future system behaviour, irrespective of repository host rock, EBS and waste type.

Specifically, the objectives of LCS are:

• Closing the circle (Figure 1) of laboratory work - in situ experiments - modelling - natural analogue studies, leading to improved system understanding of the implications of cement leachate interactions in a repository.
  
  
• Providing a firm basis for reactive transport modelling and demonstrating the ability to reconcile and predict the relevant processes.
  
  
• Performing a long-term in situ demonstration experiment under realistic boundary conditions, possibly with a solid source for the cement leachates.
  
  
• Supporting the above objectives with focussed laboratory experiments.
  
  
• Improve mechanistic understanding (by experiments and/or modelling) to the point where all participating organisations can address their own site-specific and design-specific issues.

Figure 1. Closing the circle (after Alexander et al., 1998).