2.5. After site selection, for any disposal programme, a number of activities, grouped in broad areas, should be undertaken, namely, detailed site characterization and confirmation, design of the geological disposal facility, construction of the disposal facility, operation of the disposal facility (i.e. receipt and emplacement of waste) and closure of the disposal facility. These activities may not occur sequentially and there may be overlap. The last three of these correspond to three important steps in the regulatory approval of a geological disposal facility (see Fig. 1). The inclusion of additional steps will largely be a matter of national preference. Site characterization and design activities may be expected to continue, at some level, up to facility closure.