2000 年 42 巻 1 号 p. 30-42
High Temperature Engineering Test Reactor (HTTR) is a graphite-moderated, helium-cooled reactor which has 30MW of thermal power amd 950°C of outlet coolant-gas temperature.
The fuel loading of the HTTR was started on July 1, 1998. from the core periphery. The first criticality was attained in annular type core of 19 columns on Nov. 10, 1998.
The startup core physics tests consisted mainly of tests for licensing and tests for establishing the technology bases necessary for HTGRs. It was confirmed in the former tests that all fuel blocks are loaded in certain positions and the excess reactivity is less than the limit. Experimental data for the annular core are obtained in the latter tests. Also, it was confirmed that the inverse kinetics method and delayed integral counting method are useful for the measurement of scram reactivity even if it takes about 10s for rod insertions. Furthermere, control rod worth curve, axial neutron flux distribution, etc. were measured to grasp the core performance.
All tests planned in the startup core physics tests had been successfully performed and were completed on Jan. 21, 1999. It was confirmed from the tests that the HTTR was capable to step up to the power ascension tests.