REACTOR DEVELOPMENTS FOR HIGH TEMPERATURE PROCESSES.

Problems connected with the development of nuclear reactors to provide direct heat for high temperature chemical processes are examined. This application will depend for its economic viability on the possibility of raising the temperature of the coolant to a substantially higher level than that of any chemical involved. Helium temperatures from the reactor core in excess of 1000 degree C are clearly desirable. Dual function systems are also highly desirable to obtain a maximum utilization of the heat from reactors of any given size. The current status and development progress of coated particle fuels for high temperature reactors gives complete confidence in the possibility of achieving the necessary high helium temperatures. The most difficult problems are expected to arise in connection with the materials which will be used outside the core in the highest temperature regions of the primary circuit of the reactors, particularly in the primary heat exchangers. At helium temperatures beyond 1000 degree C it may not be possible to rely on the use of metals for such purposes and recourse to ceramics or graphite in components and structures might be required.