1. Department of Geosciences, University of Oslo, P.O. Box 1047 Blindern, 0316 Oslo, Norway
2. Laboratory for Waste Management (LES), Paul Scherrer Institute, CH-5232 Villigen, Switzerland
3. The University Centre in Svalbard (UNIS),
P.O. Box 156, N-9171 Longyearbyen, Norway