Investigation of the methodology for selecting cementitious materials for the different components in the underground facility. Deriving component requirements and investigation of the weighting methodology

For conceptual facility design, it is necessary to select appropriate cementitious materials to meet the requirements for each component of the underground disposal facility before detailed investigations are carried out for site selection. Cementitious materials will be used for constructing major components of the underground facility and suitable materials for each component are selected tentatively by comparing the selection methodology with relevant information about the component for which the cementitious material will be used. The objective of this study is to list and sort the required characteristics of cementitious materials for each component in the facility, in order to provide input for determining the material selection methodology. When deriving the required characteristics of the cementitious materials for each component, physico-chemical properties that will fulfil required operational functions and minimize effects on the safety function of the disposal system due to alteration or degradation were investigated. Based on these investigations, step changes in the state of the disposal system are identified, including the bedrock around the drifts, by considering alteration or degradation of the cementitious material. Significant components for ensuring the safety function can be identified by specifying the step changes in the state of the disposal system. (author)