Near term test plan using HTTR (High Temperature engineering Test Reactor)

Takada, Shoji; Iigaki, Kazuhiko ; Shinohara, Masanori ; Tochio, Daisuke ; Shimazaki, Yosuke ; Ono, Masato ; Yanagi, Shunki; Nishihara, Tetsuo ; Fukaya, Yuji   ; Goto, Minoru  ; Tachibana, Yukio ; Sawa, Kazuhiro

JAEA has carried out research and development to establish the technical basis of HTGRs using HTTR. To connect hydrogen production system to HTTR, it is necessary to ensure the reactor dynamics when thermal-load of the system is lost. Thermal-load fluctuation test is planned to demonstrate the reactor dynamics stability and to validate plant dynamics codes. It will be confirmed that the reactor become stable state during losing a part of removed heat at heat-sink. A temperature coefficient of reactivity is one of the important parameters for core dynamics calculations, and changes with burnup because of variance of fuel compositions. Measurement of temperature coefficient of reactivity has been conducted to confirm the validity of calculated temperature coefficient of reactivity. A LOFC test using HTTR has been carried out to verify the inherent safety under the condition of LOFC while the reactor shut-down system disabled.