Long-term high-temperature operation of the HTTR

Goto, Minoru  ; Shinohara, Masanori ; Tochio, Daisuke ; Shimazaki, Yosuke ; Hamamoto, Shimpei  ; Tachibana, Yukio 

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) Coated fuel particle (CFP) 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, and (3) The intermediate heat exchanger keeps excellent heat transfer performance from beginning of operation. Additionally, the following two issues were validated using the HTTR burnup data. (1) The effectiveness of rod-type burnable poisons on reactivity control in the HTTR, and (2) The whole core burnup calculation method for nuclear characteristics of the HTTR.