1. Dep. of Chemical and Biochemical Eng., Ctr. for Ecosystems and Environmental Sustainability; Technical Univ. of Denmark; DK-2800 Kongens Lyngby Denmark
2. Dep. of Geosciences and Natural Resource Management; Copenhagen Univ.; DK-1350 Copenhagen Denmark
3. Geochemical Dep.; Geological Survey of Denmark and Greenland; DK-1350 Copenhagen Denmark
4. Inst. for Environment; Health, and Safety, Belgian Nuclear Research Ctr. (SCK•CEN); B-2400 Mol Belgium