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Tada, Kenichi; Kondo, Ryoichi; Endo, Tomohiro*; Yamamoto, Akio*
Journal of Nuclear Science and Technology, 60(6), p.624 - 631, 2023/06
Times Cited Count：2 Percentile：53.91(Nuclear Science & Technology)The sensitivity analysis and the uncertainty quantification have an important role in improving the evaluated nuclear data library. The current computational performance enables us to the sensitivity analysis and uncertainty quantification using the continuous energy Monte Carlo calculation code. The ACE file perturbation tool was developed for these calculations using modules of FRENDY. This tool perturbs the microscopic cross section, the number of neutrons per fission, and the fission spectrum. The uncertainty quantification using the random sampling method is also available if the user prepares the covariance matrix. The uncertainty of the k-effective using the perturbation tool was compared to the current sensitivity analysis codes SCALE/TSUNAMI and MCNP/KSEN. The comparison results indicated that the random sampling method using this tool accurately estimates the uncertainty of k-effective.
Tazaki, Makiko; Kimura, Takashi; Shimizu, Ryo; Tamai, Hiroshi; Nakatani, Takayoshi; Suda, Kazunori
JAEA-Review 2022-020, 82 Pages, 2022/09
JAEA-Review-2022-020.pdf:2.14MB
As part of the "Research on Factor Analysis and Technical Processes for Achieving Denuclearization" started in 2018, comprehensive survey of nuclear development and denuclearization of Iraq was conducted, together with analysis of the characteristics and lessons learned from the denuclearization. Iraq's clandestine nuclear weapon related activities were initially focused on plutonium production, but it then switched its focus on producing highly enriched uranium, and built various facilities, including electromagnetic isotope separation (EMIS) and centrifuge uranium enrichment facilities. Denuclearization of Iraq began with the defeat in the 1991 Gulf War, which forced Iraq to accept United Nations Security Council Resolution 687 (1991) that year. The Resolution set out a framework for destruction, removal, or rendering harmless of Iraq's weapons of mass destruction (WMD) programs. Within the framework, the International Atomic Energy Agency (IAEA), with the support and cooperation of the newly established United Nations Special Commission (UNSCOM), had verified Iraq's past nuclear activities and denuclearization. Characteristics of Iraq's denuclearization include that 1) Iraq had no choice but to accept denuclearization, 2) IAEA was empowered to implement detectable inspection measures and methods, which later came to fruition as the IAEA Safeguards Agreement Additional Protocol (AP), 3) economic sanctions for the purpose of promoting denuclearization of Iraq were not very successful, and 4) denuclearization of Iraq and subsequent Iraq war, together with collapse of the Hussein regime, has affected the denuclearization of Libya, North Korea and Iraq. Furthermore, the lessons learned from the denuclearization are 1) the need for universalization of AP, and necessities for 2) economic sanctions that are suitable for the original purposes without being abused, 3) the need for diplomatic efforts including denuclearization frameworks and measures with a clear roadmap
Cs in water and phyto- and zooplankton in a reservoir affected by the Fukushima Daiichi Nuclear Power Plant AccidentTsuji, Hideki*; Nakagawa, Megumi*; Iijima, Kazuki; Funaki, Hironori; Yoshimura, Kazuya; Sakuma, Kazuyuki; Hayashi, Seiji*
Global Environmental Research (Internet), 24(2), p.115 - 127, 2021/06
Lake water, phytoplankton and zooplankton were sampled by a total of 12 quarterly surveys from August 2014 to May 2017 at a dam lake in the Fukushima nuclear disaster area, and variations of dissolved form of Cs and planktonic Cs were observed. Seasonal variations in dissolved Cs concentration with high in summer and low in winter were observed in the upstream, midstream and downstream areas of the lake, but no seasonal or site specific differences in planktonic Cs concentrations and dominant species were found. The amount of planktonic form of Cs in the water was less than 1.4% of the total Cs in the lake water, therefore the effect of plankton on the dynamics of Cs in the lake was minimal.
Takechi, Seiichi*; Tsuji, Hideki*; Koshikawa, Masami*; Ito, Shoko*; Funaki, Hironori; Hayashi, Seiji*
Rikusuigaku Zasshi, 82(1), p.1 - 16, 2021/02
Since the Fukushima Daiichi Nuclear Power Plant accident in 2011, soil minerals and organic matter including radiocesium have been deposited in the dam lakes near the nuclear power plant. There is concern that radiocesium will gradually leach from the lake bottom into the lake water, resulting in prolonged radioactive contamination of the freshwater ecosystems especially in downstream of the dams. In this study, we collected undisturbed sediment core samples at the center of the Yokokawa Dam lake in Fukushima Prefecture and suspended sediment in the inflowing river of the dam for 4 years and evaluated the amount of bioavailable form of radiocesium (exchanged, oxidized, and organic forms) in these samples by sequential extraction tests using the BCR method focusing on the temporal change.
Kondo, Ryoichi*; Endo, Tomohiro*; Yamamoto, Akio*; Tada, Kenichi
Proceedings of International Conference on Mathematics and Computational Methods applied to Nuclear Science and Engineering (M&C 2019) (CD-ROM), p.1493 - 1502, 2019/00
A perturbation capability of ACE formatted cross section files was developed using the modules of FRENDY. Uncertainty quantification using MCNP was carried out for the Godiva critical experiment by the RS method. We verified the results of the RS method by comparing with those obtained by the conventional sensitivity analyses. Moreover, uncertainty reduction using the bias factor method with the RS technique was applied to kinetic parameter, i.e., neutron generation time.
Stankovskiy, A.*; Iwamoto, Hiroki; 
elik, Y.*; Van den Eynde, G.*
Annals of Nuclear Energy, 120, p.207 - 218, 2018/10
Times Cited Count：8 Percentile：62.99(Nuclear Science & Technology)Propagation of high-energy (above 20-MeV) nuclear data uncertainties on the safety related neutronic responses in accelerator driven systems has been assessed. The total core power and production of radionuclides contributing to radiation source terms were focused on. The article features a method based on the Monte Carlo sampling of random nuclear data files from the covariance matrices generated from the sets of reaction cross sections obtained with model calculations of high-energy particle interactions with matter or picked up from already existing nuclear data libraries. It has been demonstrated that nuclear data uncertainties do not need to be propagated through particle transport calculations to obtain uncertainties on the responses. This advantage allowed to investigate the convergence of the sample average to the best estimate. The number of random nuclear data file sets needed to obtain reliable uncertainty on the total core power is around 300 that results in the uncertainty of 14%. The uncertainties on the concentrations of nuclides most important for the safety assessment that are accumulated in lead-bismuth eutectic during irradiation, range from 5 to 60%. Concentrations of some nuclides exemplified by Tritium converge much slower than neutron multiplicities so that several thousands of samples are needed to ensure reliable uncertainty estimates.
Watanabe, Takayoshi; Oyama, Takuya; Ishii, Yasuo; Niizato, Tadafumi; Abe, Hironobu; Mitachi, Katsuaki; Sasaki, Yoshito
KEK Proceedings 2017-6, p.122 - 126, 2017/11
no abstracts in English
Ye, F.*; Matsuda, Masaaki; Katano, Susumu; Yoshizawa, Hideki*; Belanger, D. P.*; Sepp
l, E. T.*; Fernandez-Baca, J. A.*; Alava, M. J.*
Journal of Magnetism and Magnetic Materials, 272-276, p.1298 - 1299, 2004/05
Times Cited Count：8 Percentile：41.01(Materials Science, Multidisciplinary)no abstracts in English
Kohara, Shinji*; Suzuya, Kentaro
Hoshako, 14(5), p.365 - 375, 2001/11
no abstracts in English
Ono, Hideo; Kohara, Shinji*; Umesaki, Norimasa*; Suzuya, Kentaro
Journal of Non-Crystalline Solids, 293-295, p.125 - 135, 2001/11
Times Cited Count：23 Percentile：70.56(Materials Science, Ceramics)no abstracts in English
2000/12)Kobayashi, Hideo; ; ; ; ; *; *
JNC TN8440 2001-005, 33 Pages, 2001/02
JNC-TN8440-2001-005.pdf:1.24MB
Four mass spectrometers are used for plutonium and uranium isotopic composition analysis in the Plutonium Fuel Center. Analytical errors of the analysis was evaluated based on routine control data obtained with measurement of reference materials. It was confirmed that the errors satisfied the International Target Values for safeguard analysis, and the random error of the analysis was improved by changing conventional method to total evaporation method.
Fujita, Ayumi
Physical Review B, 62(22), p.15190 - 15194, 2000/12
Times Cited Count：4 Percentile：27.84(Materials Science, Multidisciplinary)no abstracts in English
JNC TJ4420 2000-002, 794 Pages, 2000/03
JNC-TJ4420-2000-002.pdf:23.42MB
no abstracts in English
Mizuki, Junichiro; Konishi, Hiroyuki; Nishihata, Yasuo; Takahashi, Masamitsu; Suzuya, Kentaro; Matsumoto, Norimasa; Yoneda, Yasuhiro
Nihon Kessho Gakkai-Shi, 42(1), p.68 - 75, 2000/02
no abstracts in English
Sugihara, Yoichiro*; Mukai, Katsuyuki*; Nunomiya, Ichiro*
PNC TJ6357 97-001, 40 Pages, 1997/03
None
Enoeda, Mikio; Kawamura, Yoshinori; Okuno, Kenji; Tanaka, Kenichi*; Uetake, Mitsuru*; Nishikawa, Masabumi*
Fusion Technology, 28(3), p.591 - 596, 1995/10
no abstracts in English
Mitomo, Hiroshi*; Morishita, Norio; *
Polymer, 36(13), p.2573 - 2578, 1995/00
Times Cited Count：49 Percentile：87.45(Polymer Science)no abstracts in English
