Outline of High Temperature Engineering Test Reactor

High Temperature Engineering Test Reactor (HTTR)is the first and only one high-temperature gas-cooled reactor in Japan. The first criticality of the HTTR was achieved on November 10,1998. The reactor outlet coolant temperature of 950°C under full thermal power of 30MW was achieved on April 19, 2004 for the first time in the world. From January to March in 2010, HTTR was operated successfully for 50 days under high temperature and full power conditions.

• Thermal Power : 30MW
• Coolant : Helium gas
• Outlet / Inlet coolant temperature : 395 / 850, 950°C
• Primary coolant pressure : 4MPa
• Core Material : Graphite
• Core Height / Core Diameter :2.9m / 2.3m
• Average Power Density :2.5MW/m³
• Fuel : Low Enriched UO₂·Coated particle / Graphite dispersion Type
• Fuel Element Type :Pin in block Type
• Reactor pressure vessel :Steel( 2·1/4Cr-1Mo )