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Yanagisawa, Hiroshi; Umeda, Miki; Motome, Yuiko; Murao, Hiroyuki
JAEA-Technology 2022-030, 80 Pages, 2023/02
Nuclear criticality benchmark analyses were carried out for TRIGA-type reactor systems in which uranium-zirconium hydride fuel rods are loaded by using the continuous-energy Monte Carlo code MVP with the evaluated nuclear data library JENDL-5. The analyses cover two sorts of benchmark data, the IEU-COMP-THERM-003 and IEU-COMP-THERM-013 in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) Handbook, and effective neutron multiplication factors, reactivity worths for control rods etc. were calculated by JENDL-5 in comparison with those by the previous version of JENDL. As the results, it was confirmed that the effective neutron multiplication factors obtained by JENDL-5 were 0.4 to 0.6% greater than those by JENDL-4.0, and that there were no significant differences in the calculated reactivity worths by between JENDL-5 and JENDL-4.0. Those results are considered to be helpful for the confirmation of calculation accuracy in the analyses on NSRR control rod worths, which are planned in the future.
Nagaya, Yasunobu; Mori, Takamasa
Journal of Nuclear Science and Technology, 42(5), p.428 - 441, 2005/05
Times Cited Count:64 Percentile:95.83(Nuclear Science & Technology)A new method to estimate a change in the effective multiplication factor due to the perturbed fission source distribution has been proposed for Monte Carlo perturbation calculations with the correlated sampling and differential operator sampling techniques. The method has been implemented into the MVP code for verification. Simple benchmark problems have been set up for fast and thermal systems and the applicability of the method has been verified with the problems. In consequence, it has been confirmed that the method is very effective to estimate the change. It has been also shown that there are some cases where the perturbed source effect is significant and the change in reactivity cannot be estimated accurately without taking the effect into account. Even in such cases, the new method can estimate the perturbed source effect and the estimation of the change in reactivity has been remarkably improved.
Cullen, D. E.*; Blomquist, R. N.*; Dean, C.*; Heinrichs, D.*; Kalugin, M. A.*; Lee, M.*; Lee, Y. K.*; MacFarlane, R.*; Nagaya, Yasunobu; Trkov, A.*
UCRL-TR-203892, p.1 - 40, 2004/04
no abstracts in English
Takamatsu, Kuniyoshi; Shimakawa, Satoshi; Nojiri, Naoki; Fujimoto, Nozomu
JAERI-Tech 2003-081, 49 Pages, 2003/10
In the case of evaluations for the highest temperature of the fuels in the HTTR, it is very important to expect the power density distributions accurately; therefore, it is necessary to improve the analytical model with the neutron diffusion and the burn-up theory. The power density distributions are analyzed in terms of two models, the one mixing the fuels and the burnable poisons homogeneously and the other modeling them heterogeneously. Moreover these analytical power density distributions are compared wtih the ones derived from the gross -ray measurements and the Monte Carlo calculational code with continuous energy. As a result the homogeneous mixed model isn't enough to expect the power density distributions of the core in the axial direction; on the other hand, the heterogeneous model improves the accuracy.
Nojiri, Naoki; Nakano, Masaaki; Ando, Hiroei; Fujimoto, Nozomu; Takeuchi, Mitsuo; Fujisaki, Shingo; Yamashita, Kiyonobu
JAERI-Tech 98-032, 59 Pages, 1998/08
no abstracts in English
Nakano, Masaaki; Yamashita, Kiyonobu; Fujimoto, Nozomu; Nojiri, Naoki; Takeuchi, Mitsuo; Fujisaki, Shingo; ; Nakata, Tetsuo*
JAERI-Tech 98-017, 61 Pages, 1998/05
no abstracts in English
Nagaya, Yasunobu; Nakagawa, Masayuki; Mori, Takamasa
Journal of Nuclear Science and Technology, 35(1), p.6 - 19, 1998/01
Times Cited Count:3 Percentile:31.90(Nuclear Science & Technology)no abstracts in English
Yamashita, Kiyonobu; Shindo, Ryuichi; Murata, Isao
The Safety,Status and Future of Non-Commercial Reactors and Irradiation Facilities,Vol. 1, p.350 - 358, 1990/09
no abstracts in English
Okuno, Hiroshi; Naito, Yoshitaka; ;
JAERI-M 89-140, 32 Pages, 1989/10
no abstracts in English
; ;
JAERI-M 86-140, 39 Pages, 1986/09
no abstracts in English
JAERI-M 85-139, 34 Pages, 1985/09
no abstracts in English
Kikuchi, Yasuyuki; Narita, Tsutomu;
Journal of Nuclear Science and Technology, 17(7), p.567 - 570, 1980/00
Times Cited Count:15 Percentile:93.41(Nuclear Science & Technology)no abstracts in English