1. Rockwell International, Rocketdyne Division, Canoga Park, California 91309
2. Missouri University Research Reactor, University of Missouri‐Columbia, Columbia, Missouri 65211
3. Department of Chemical Engineering, University of Missouri‐Columbia, Columbia, Missouri 65211
4. Central Research Institute of Electric Power Industry, Komae Research Laboratory, Tokyo, Japan
5. Kawasaki Heavy Industries, Limited, Nuclear Systems Division, Tokyo, Japan