R&D on components

The following R&D on components were carried out for the design, safety review and performance evaluation of the HTTR; fuel, core components and reactor internals, passive cooling system, intermediate heat exchanger, and basic feature of air ingress during primary pipe rupture accident. As for the fuel, the design criteria and specifications for the HTTR, and fabrication process are described. As for core components and reactor internals, thermal-hydraulic tests on the core and core bottom structure of the HTTR were carried out with the helium engineering demonstration loop (HENDEL) under simulated reactor operating conditions. As for the IHX, experimental and numerical studies with partial models were carried out. This chapter explained the performance and structural integrity of the fuel core components and reactor internals were verified in advance by the research and development.