Design of High Temperature Engineering Test Reactor (HTTR)

Abstract The following design details of the high temperature engineering test reactor (HTTR) are described: nuclear, thermal-hydraulic seismic and safety performance, metal and graphite components, core components and reactor internals, and cooling, reactivity control, instrumentation and control systems. The new design criteria have been developed for graphite structures, and a super heat-resistant alloy, Hastelloy XR, was newly developed for high temperature components such as heat transfer tubes of an intermediate heat exchanger. The performance and structural integrity of the fuel core components and reactor internals were verified in advance by the research and development described in Chapter 3, R&D on Components. As for the safety design, the strategy of defense in depth was implemented so that the safety engineering functions such as control of reactivity, removal of residual heat, and confinement of fission products shall be well performed to ensure safety.