A STUDY OF FISSION PRODUCTS IN THE MOLTEN-SALT REACTOR EXPERIMENT BY GAMMA SPECTROMETRY

摘要

The operation of the Molten-Salt Reactor Experiment (MSRE) has demonstrated that a mixture of fluoride salts is a practical fluid fuel that is quite stable under reactor conditions. The chemistry of the fission products is such, however, that some of them leave the circulating fuel salt and appear on the moderator graphite in the core, on the metal surfaces exposed to the salt, and on the metal surfaces in the off-gas system. Xenon and krypton fission gases are stripped in the off-gas system, where they decay to daughter nuclides. Some other elements (Mo, Nb, Ru, Te, and Sb) appear to exist in the metallic state and tend to plate out on metal or graphite surfaces or be carried out into the off-gas system as particles. Because it is important in the design of larger molten-salt reactor systems to know where and in what proportion fission products are distributed throughout the system, considerable efforts were made to obtain this information in the MSRE.