High temperature gas-cooled reactors

Takeda, Tetsuaki*; Inagaki, Yoshiyuki; Aihara, Jun; Aoki, Takeshi; Fujiwara, Yusuke; Fukaya, Yuji; Goto, Minoru; Ho, H. Q.; Iigaki, Kazuhiko; Imai, Yoshiyuki; et al.

High Temperature Gas-Cooled Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.5, 464 Pages, 2021/02

https://doi.org/10.1016/C2018-0-05383-9

As a general overview of the research and development of a High Temperature Gas-cooled Reactor (HTGR) in JAEA, this book describes the achievements by the High Temperature Engineering Test Reactor (HTTR) on the designs, key component technologies such as fuel, reactor internals, high temperature components, etc., and operational experience such as rise-to-power tests, high temperature operation at 950C, safety demonstration tests, etc. In addition, based on the knowledge of the HTTR, the development of designs and component technologies such as high performance fuel, helium gas turbine and hydrogen production by IS process for commercial HTGRs are described. These results are very useful for the future development of HTGRs. This book is published as one of a series of technical books on fossil fuel and nuclear energy systems by the Power Energy Systems Division of the Japan Society of Mechanical Engineers.

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.

Establishment of control technology of the HTTR and future test plan

Honda, Yuki; Saito, Kenji; Tochio, Daisuke; Aono, Tetsuya; Hirato, Yoji; Kozawa, Takayuki; Nakagawa, Shigeaki

Journal of Nuclear Science and Technology, 51(11-12), p.1387 - 1397, 2014/11

https://doi.org/10.1080/00223131.2014.919241

The operational experiments of the HTTR would be useful for future high-temperature gas-cooled reactors (HTGRs). Main PID control constants of the HTTR are selected with reasonably damped characteristics and without undershoot or overshoot. For utilization the HTGR as a commercial reactor, it should be demonstrated that the HTGR system can supply stable heat to a heat utilization system for the long-term operation. The control characteristics in the long-term high-temperature operation are evaluated by the result of operation performed in 2010. In addition, from a viewpoint of HTGRs with heat utilization system, a future possibility of the experiments for heat utilization design is examined.

Integrated on-line plant monitoring system for HTTR with neural networks

Nabeshima, Kunihiko; Subekti, M.*; Matsuishi, Tomomi*; Ono, Tomio*; Kudo, Kazuhiko*; Nakagawa, Shigeaki

Journal of Power and Energy Systems (Internet), 2(1), p.92 - 103, 2008/00

https://doi.org/10.1299/jpes.2.92

The neural networks have been utilized in on-line monitoring-system of High Temperature Engineering Tested Reactor (HTTR) with thermal power of 30 MW. In this system, several neural networks can independently model the plant dynamics with different architecture, input and output signals and learning algorithm. One of main task is real-time plant monitoring by Multi-Layer Perceptron (MLP) in auto-associative mode, which can model and estimate the whole plant dynamics by training normal operational data only. Other tasks are on-line reactivity prediction, reactivity and helium leak monitoring, respectively. From the on-line monitoring results at the safety demonstration tests, each neural network shows good prediction and reliable detection performances.

Benchmark experiments of MOX fueled LMFBR using FCA-XVII-1 core

Ando, Masaki; Iijima, Susumu*; Oigawa, Hiroyuki; Sakurai, Takeshi; Nemoto, Tatsuo*; Okajima, Shigeaki; Osugi, Toshitaka*; Ono, Akio; Hayasaka, Katsuhisa; Sodeyama, Hiroshi

JAEA-Data/Code 2006-006, 67 Pages, 2006/03

JAEA-Data-Code-2006-006.pdf:6.08MB

As a part of research and development of an advanced fueled fast reactor, we carried out benchmark experiments in the FCA-XVII-1 core with MOX simulating fuel to obtain reference data to be compared with those measured in the FCA-XVI-1 and XVI-2 cores simulating metallic fueled FBR. Following nuclear characteristics were measured in the experiments: Criticality, reaction rate ratio, sample reactivity worth, sodium void reactivity effect and U Doppler effect. Extra measurements were performed in modified FCA-XVII-1 cores to obtain experimental data for various reactor types: (1) Measurement of sodium void reactivity effect in various plutonium isotope compositions, (2) Measurement of sodium void reactivity effect in a core where axial blanket was replaced with a sodium layer and (3) Measurement of various nuclear characteristics in a nitride fuel region. This report describes methods and results of the above experiments and method of analysis.

Stability of magnesite and its high-pressure form in the lowermost mantle

Isshiki, Maiko*; Irifune, Tetsuo*; Hirose, Kei*; Ono, Shigeaki*; Oishi, Yasuo*; Watanuki, Tetsu; Nishibori, Eiji*; Takata, Masaki*; Sakata, Makoto*

Nature, 427(6969), p.60 - 63, 2004/01

https://doi.org/10.1038/nature02181

no abstracts in English

observation of ilmenite-perovskite phase transition in MgSiO using synchrotron radiation

Ono, Shigeaki*; Katsura, Tomoo*; Ito, Eiji*; Kanzaki, Masami*; Yoneda, Akira*; Walter, M.*; Urakawa, Satoru*; Utsumi, Wataru; Funakoshi, Kenichi*

Geophysical Research Letters, 28(5), p.835 - 838, 2001/03

https://doi.org/10.1029/1999GL008446

no abstracts in English

Hybrid monitoring system for high temperature gas cooling reactor

Nabeshima, Kunihiko; Tuerkcan, E.*; Suzudo, Tomoaki; Nakagawa, Shigeaki; Inoue, K.*; Oono, Tomio*; *; Suzuki, Katsuo

Proc. of Human-Computer Interaction International'99, 2, p.1187 - 1191, 1999/00

no abstracts in English

Reactor physics experiments and analyses on high conversion light water reactor

Osugi, Toshitaka; Okajima, Shigeaki; Ono, Akio; Obu, Makoto; ;

Proc. ANS Int. Reactor Physics Conf., Vol. 2, p.361 - 370, 1988/00

no abstracts in English

Soundness confirmation of systems and instruments by cold test of HTTR

Ono, Masato; Shinohara, Masanori; Iigaki, Kazuhiko; Tochio, Daisuke; Nakagawa, Shigeaki; Shimazaki, Yosuke

no journal, , 

In HTTR, it has passed about two years since the last performance confirmation test. During two years, the integrity of active equipment, leakage efficiency of coolant pressure boundary of piping and vessel and control system performance due to influence of damage and deterioration by earthquake and aging were not confirmed. To confirm them, the cold test by using HTTR was conducted and the system performances such as above mentioned items were evaluated by comparing with the plant data obtained by the past cold test. In the result, no abnormity was found in all the data in the cooling system of HTTR, and it was confirmed that the integrity of facilities and instruments of HTTR was maintained in good condition.