Investigation of countermeasure against local temperature rise in vessel cooling system in loss of core cooling test without nuclear heating

Ono, Masato; Shimizu, Atsushi; Kondo, Makoto; Shimazaki, Yosuke; Shinohara, Masanori; Tochio, Daisuke; Iigaki, Kazuhiko; Nakagawa, Shigeaki; Takada, Shoji; Sawa, Kazuhiro

Journal of Nuclear Engineering and Radiation Science, 2(4), p.044502_1 - 044502_4, 2016/10

https://doi.org/10.1115/1.4032478

In the loss of forced core cooling test using High Temperature engineering Test Reactor (HTTR), the forced cooling of reactor core is stopped without inserting control rods into the core and cooling by Vessel Cooling System (VCS) to verify safety evaluation codes to investigate the inherent safety of HTGR be secured by natural phenomena to make it possible to design a severe accident free reactor. The VCS passively removes the retained residual heat and the decay heat from the core via the reactor pressure vessel by natural convection and thermal radiation. In the test, the local temperature was supposed to exceed the limit from the viewpoint of long-term use at the uncovered water cooling tube by thermal reflectors in the VCS, although the safety of reactor is kept. Through a cold test, which was carried out by non-nuclear heat input from gas circulators with stopping water flow in the VCS, the local higher temperature position was specified although the temperature was sufficiently lower than the maximum allowable working temperature, and natural circulation of water had insufficient cooling effect on the temperature of water cooling tube below 1C. Then, a new safe and secured procedure for the loss of forced core cooling test was established, which will be carried out soon after the restart of HTTR.

Study on natural convection heat transfer in vertical annular space of a double coaxial cylinder

Inaba, Yoshitomo; Takeda, Tetsuaki

JAERI-Research 2000-062, 73 Pages, 2001/02

JAERI-Research-2000-062.pdf:2.83MB

no abstracts in English

Safety analyses in the High Temperature Engineering Test Reactor(HTTR) related to the inherent safety during depressurization accidents

Kunitomi, Kazuhiko; Nakagawa, Shigeaki; Fujimoto, Nozomu; Shindo, Masami; Sudo, Yukio

The Safety,Status and Future of Non-Commercial Reactors and Irradiation Facilities,Vol. 1, p.281 - 286, 1990/10

no abstracts in English