How to mark repositories in geological formation

The disposal of nuclear waste in deep geological formations provides a safe means of isolating the waste from people until the radioactivity has decayed. However, preventing people from intruding waste isolation systems is a different problem since it is difficult to foresee future human activities. It has therefore appeared that it is necessary to look for some reasonable means to reduce still further the probability of inadvertent human intrusion in the future. This paper presents a general reflection on how this goal could be reached and does not correspond to an official position which may be taken by ANDRA. (authors). 1 fig., 9 refs