NEW DEVELOPMENTS IN MATERIALS FOR MOLTEN-SALT REACTORS
H. E. McCOY, R. L. BEATTY, W. H. COOK, R. E. GEHLBACH, C. R. KENNEDY, J. W. KOGER, A. P. LITMAN, C. E. SESSIONS and J. R. WEIR
Metals and Ceramics Division, Oak Ridge National Laboratory
Oak Ridge, Tennessee 37830
October 10, 1969
Operating experience with the Molten-Salt Reactor Experiment (MSRE) has demonstrated the excellent compatibility of the graphite-Hastelloy N-fluoride salt system at 650°C. Several improvements in materials are needed for a molten-salt breeder reactor with a basic plant life of 30 years; specifically: Hastelloy-N with improved resistance to embrittlement by thermal neutrons; graphite with better dimensional stability in a fast neutron flux; graphite that is sealed to obtain a surface permeability of <10-8 cm2 /sec; and a secondary coolant that is inexpensive and has a melting point of ~4o0°C. A brief description is given of the materials work in progress to satisfy each of these requirements.