Design, construction and utilization of High Temperature Engineering Test Reactor (HTTR)

The High Temperature Engineering Test Reactor (HTTR) is graphite moderated and cooled by helium gas, and prismatic fuel elements in the form of hexagonal blocks are used. The thermal output of the reactor is 30 MW and its highest outlet coolant temperature is 950degC which is achieved by various considerations in the design together with extensive research and development. Several important safety considerations for fuels, reactor shut-down system, back-up reactor cooling system, multiple barriers against FP release were also adopted in the design of HTTR. The construction of the HTTR facility is currently, progressing and the first criticality will be attained in FY 1996. The HTTR is used for establishing and upgrading the HTGR technology basis including safety demonstration and high temperature nuclear heat application. (author)