National Policies in the Planning of Preand Post-Closure Actions

In their planning of repository construction, operation and closure, some programmes are considering concepts that include an extended “open period”, in which the waste is kept readily retrievable and there is flexibility in the timing of any decision to backfill and seal the underground openings in which the waste is emplaced, which may be delayed perhaps for some hundreds of years (Appendix 4, observations from responses to Question 5.1b). Such concepts aim to combine, to some extent, the positive aspects of geological disposal, in terms of passive safety and security, and longterm storage, in terms of flexibility in decision-making. 