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Isogawa, Hiroki*; Naoi, Motomasa*; Yamasaki, Seiji*; Ho, H. Q.; Katayama, Kazunari*; Matsuura, Hideaki*; Fujimoto, Nozomu*; Ishitsuka, Etsuo
JAEA-Technology 2022-015, 18 Pages, 2022/07
As a summer holiday practical training 2021, the impact of 10 years long-term shutdown on critical control rod position of the HTTR and the delayed neutron fraction () of the VHTRC-1 core were investigated using Monte-Carlo MVP code. As a result, a long-term shutdown of 10 years caused the critical control rods of the HTTR to withdraw about 4.00.8 cm compared to 3.9 cm in the experiment. The change in critical control rods position of the HTTR is due to the change of some fission products such as Pu, Am, Pm, Sm, Gd. Regarding the calculation of the VHTRC-1 core, the value is underestimate of about 10% in comparison with the experiment value.
Okita, Shoichiro; Nagaya, Yasunobu; Fukaya, Yuji
Journal of Nuclear Science and Technology, 58(9), p.992 - 998, 2021/09
Times Cited Count:2 Percentile:31.78(Nuclear Science & Technology)Fujimoto, Nozomu; Nojiri, Naoki; Yamashita, Kiyonobu*
Nuclear Engineering and Design, 233(1-3), p.155 - 162, 2004/10
Times Cited Count:2 Percentile:17.18(Nuclear Science & Technology)The HTTR uses low-enriched uranium fuel with burnable poison rod. For validation of the nuclear design code system for the HTTR, a critical assembly of VHTRC had been constructed. The calculation uncertainties of effective multiplication factor, neutron flux distribution, burnable poison reactivity worth, and control rod worth, temperature coefficients were evaluated. Calculation accuracy of a Monte Carlo code is also evaluated.
Suzuki, Katsuo; Nabeshima, Kunihiko; Yamane, Tsuyoshi; Fujii, Yoshio*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 2(4), p.408 - 417, 2003/12
On-line and real-time estimation of time-varying reactivity in a nuclear reactor is necessary for early detection of reactivity anomaly and safe operation. Using a digital nonlinear H estimator, an experiment of real-time dynamic reactivity estimation was carried out in the VHTRC of JAERI. Some technical issues of the experiment are described, such as reactivity insertion, data sampling frequency, anti-aliasing filter, experimental circuit and digitalizing nonlinear H reactivity estimator, and so on. Then, we discussed the experimental results obtained by the digital nonlinear H estimator with sampled data of the nuclear instrumentation signal for the power responses under various reactivity insertions. Good performances of estimated reactivity were observed, with almost no delay to the true reactivity and sufficient accuracy between 0.05cent and 0.1cent. From the results of the experiment, it is concluded that the digital nonlinear H reactivity estimator can be applied as on-line real-time reactivity meter for actual nuclear plants.
Yoshida, Tadashi*; Okajima, Shigeaki; Sakurai, Takeshi; Nakajima, Ken; Yamane, Tsuyoshi; Katakura, Junichi; Tahara, Yoshihisa*; Zukeran, Atsushi*; Oyamatsu, Kazuhiro*; Osawa, Takaaki*; et al.
Journal of Nuclear Science and Technology, 39(Suppl.2), p.136 - 139, 2002/08
no abstracts in English
Takeuchi, Motoyoshi; Nakajima, Katsutoshi; Fukumura, Nobuo*; Nakayama, Fusao*; Ohori, Hideshi*
Dekomisshoningu Giho, (24), p.27 - 46, 2001/09
no abstracts in English
Yasuda, Hideshi
RANDEC Nyusu, (45), p.6 - 7, 2000/05
no abstracts in English
Fujimoto, Nozomu; Yamashita, Kiyonobu; Akino, Fujiyoshi
JAERI-Research 99-052, p.51 - 0, 1999/09
no abstracts in English
Yamashita, Kiyonobu; Takeuchi, Mitsuo; Fujimoto, Nozomu; Fujisaki, Shingo; Nakano, Masaaki*; Nojiri, Naoki; Tamura, Seiji*
Nihon Genshiryoku Gakkai-Shi, 41(1), p.35 - 38, 1999/00
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)no abstracts in English
Akino, Fujiyoshi; Yamane, Tsuyoshi
Nihon Genshiryoku Gakkai-Shi, 40(4), p.262 - 264, 1998/00
no abstracts in English
Nojiri, Naoki; Yamashita, Kiyonobu; Fujimoto, Nozomu; Nakano, Masaaki*; Yamane, Tsuyoshi; Akino, Fujiyoshi
JAERI-Tech 97-060, 34 Pages, 1997/11
no abstracts in English
Akino, Fujiyoshi; Takeuchi, Motoyoshi; Ono, Toshihiko; Kaneko, Yoshihiko
Journal of Nuclear Science and Technology, 34(2), p.185 - 192, 1997/02
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)no abstracts in English
Yamashita, Kiyonobu; Ando, Hiroei; Nojiri, Naoki; Fujimoto, Nozomu; Nakata, Tetsuo*; Watanabe, Takashi*; Yamane, Tsuyoshi; Nakano, Masaaki*
Proc. of SARATOGA 1997, 2, p.1557 - 1566, 1997/00
no abstracts in English
Fujii, Yoshio; Suzuki, Katsuo; Akino, Fujiyoshi; Yamane, Tsuyoshi; Fujisaki, Shingo; Takeuchi, Motoyoshi; Ono, Toshihiko
JAERI-Data/Code 96-001, 102 Pages, 1996/02
no abstracts in English
Yamashita, Kiyonobu; Shindo, Ryuichi; Murata, Isao; Maruyama, So; Fujimoto, Nozomu; Takeda, Takeshi
Nuclear Science and Engineering, 122, p.212 - 228, 1996/00
Times Cited Count:23 Percentile:85.72(Nuclear Science & Technology)no abstracts in English
Akino, Fujiyoshi; Takeuchi, Motoyoshi; Ono, Toshihiko; Fujisaki, Shingo
PHYSOR 96: Int. Conf. on the Physics of Reactors, 2, p.E281 - E289, 1996/00
no abstracts in English
Yamane, Tsuyoshi; Akino, Fujiyoshi;
PHYSOR 96: Int. Conf. on the Physics of Reactors, 2, p.E290 - E299, 1996/00
no abstracts in English
; Yamane, Tsuyoshi
JAERI-Research 95-081, 32 Pages, 1995/11
no abstracts in English
; Yamane, Tsuyoshi; Sasa, Toshinobu
JAERI-Data/Code 94-013, 17 Pages, 1994/10
no abstracts in English
Akino, Fujiyoshi; Takeuchi, Motoyoshi; Ono, Toshihiko
Journal of Nuclear Science and Technology, 31(8), p.861 - 863, 1994/08
Times Cited Count:4 Percentile:53.92(Nuclear Science & Technology)no abstracts in English