Operation, test, research and development of the High Temperature Engineering Test Reactor (HTTR) (FY1999-2001)

Department of HTTR Project

The HTTR (High Temperature Engineering Test Reactor) with the thermal power of 30 MW and the reactor outlet coolant temperature of 850/950C is the first high temperature gas-cooled reactor (HTGR) in Japan, which uses coated-particle fuel, graphite for core components, and helium gas for primary coolant. The HTTR, which locates at the south-west area of 5000 m in the Oarai Research Establishment, had been constructed since 1991 before accomplishing the first criticality on November 10, 1998. Rise to power tests of the HTTR started in September, 1999 and the rated thermal power of 30 MW and the reactor outlet coolant temperature of 850C was attained in December 2001. JAERI received the certificate of pre-operation test, that is, the commissioning license for the HTTR in March 2002. This report summarizes operation, tests, maintenance, radiation control, and construction of components and facilities for the HTTR as well as R&Ds on HTGRs from FY1999 to 2001.