[en] The concept for the disposal of Canada's nuclear fuel waste is to dispose of the waste in an underground vault, nominally at 500 m to 1000 m depth, at a suitable site in plutonic rock of the Canadian Shield. The feasibility of this concept and assessments of its impact on the environment and human health, will be documented by AECL in an Environmental Impact Statement (EIS). This report is one of nine primary references for the EIS. It describes the approach and methods that would be used during the siting stage of the disposal project to identify a preferred candidate disposal site and to confirm its suitability for constructing a disposal facility. The siting stage is divided into two distinct but closely related substages, site screening and site evaluation. Site screening would mainly involve reconnaissance investigations of siting regions of the Shield to identify potential candidate areas where suitable vault locations are likely to exist. Site screening would identify a small number of candidate areas where further detailed investigations were warranted. Site evaluation would involve progressively more detailed surface and subsurface investigations of the candidate areas to first identify potentially suitable vault locations within the candidate areas, and then characterize these potential disposal sites to identify the preferred candidate location for constructing the disposal vault. Site evaluation would conclude with the construction of exploratory shafts and tunnels at the preferred vault location, and underground characterization would be done to confirm the suitability of the preferred candidate site. An integrated program of geological, geophysical, hydrogeological, geochemical and geomechanical investigations would be implemented to obtain the geoscience information needed to assess the suitability of the candidate siting areas and candidate sites for locating a disposal vault. The candidate siting areas and candidate disposal vault sites would be carefully characterized to understand the groundwater flow conditions in the rock. This understanding would be used to situate the disposal vault in the rock so as to allow the flow and chemical characteristics of the groundwater to enhance the safety of the disposal system. The geoscience methods for characterizing the conditions within plutonic rocks of the Canadian Shield have been developed and tested by AECL at geologic research areas on the Shield. This report presents examples of the site characterization methods which are drawn from the studies at these research areas. The geoscience work performed at the Whiteshell Research Area (WRA) on the Shield in southeastern Manitoba comes closest to illustrating the spatial coverage of characterization that would be required for siting an actual nuclear fuel waste disposal vault in a candidate area of the Shield. The characterization work done at the site of the Underground Research Laboratory (URL) in the WRA demonstrates how to evaluate the geoscience conditions of the rock at a candidate disposal site, and illustrates how that information would be used to confirm the suitability of the site for disposal. This report presents evidence from case studies at the URL and the geologic research areas that the surface-based, borehole and underground site characterization methods developed by AECL are now sufficiently developed that they can be used to obtain the geoscience information needed for siting a disposal vault in plutonic rock of the Canadian Shield. We expect that these site characterization methods will continue to be improved and that new methods will be developed during the long time period required for implementation of the disposal project. Improvements and new developments are continuing through ongoing research at the site of the URL and at the other geologic research areas on the Shield. However the methods that are currently available are sufficiently well developed to allow siting to commence. (author)