1. Department of Earth and Environmental Sciences, Division of Soil and Water Management, Katholieke Universiteit Leuven, Kasteelpark Arenberg, 20, 3001 Heverlee, Belgium
2. Department of Earth and Environmental Sciences, Division of Geology, Katholieke Universiteit Leuven, Celestijnenlaan 200 E, 3001 Heverlee, Belgium
3. FANC (Federal Agency of Nuclear Control), Ravensteinstraat 36 1000 Brussel, Belgium