1. ETH Zürich, Department of Mechanical and Process Engineering, Nuclear Safety and Multiphase Flows, Sonneggstrasse 3, Zürich 8092 Switzerland
2. Paul Scherrer Institute, Laboratory for Reactor Physics and Thermal-Hydraulics, Forschungsstrasse 111, Villigen PSI 5232 Switzerland
3. Idaho National Laboratory, 1955 North Fremont Avenue, Idaho Falls, Idaho 83415
4. University of Michigan, Department of Nuclear Engineering and Radiological Sciences, 2355 Bonisteel Boulevard, Ann Arbor, Michigan 48105