Long-term high-temperature operation in the HTTR, 1; Outline and main test results

Shinohara, Masanori ; Tochio, Daisuke ; Hamamoto, Shimpei  ; Inoi, Hiroyuki; Shinozaki, Masayuki; Nishihara, Tetsuo ; Iyoku, Tatsuo

HTTR constructed at the Oarai Research and Development Center of JAEA is the first HTGR in Japan. The reactor thermal power is 30 MW, the reactor maximum outlet coolant temperature is 850 C in rated operation mode and 950 C in high temperature test operation mode. Main objectives of the HTTR are to establish and develop HTGR technology and to demonstrate process heat application. 30-days operation in rated operation mode and 50-days operation in high-temperature operation mode were performed to obtain various characteristic data of HTGR. The main test results are as follows :(1) CPF of the HTTR has excellent confinement ability of fission product which is the highest performance in the world. (2) The measurement temperature of the core internals is good agreement with the design value so that their structural integrity is maintained. (3) The intermediate heat exchanger keeps excellent heat transfer performance from beginning of operation.