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Journal Articles

Measurement of thermal neutron capture cross section of $$^{71}$$Ga with dual monitor foils and covariance analysis

Panikkath, P.*; Otsuka, Naohiko*; Iwamoto, Yosuke; Mohanakrishnan, P.*

European Physical Journal A, 55(6), p.91_1 - 91_9, 2019/06

The thermal neutron capture cross section of $$^{71}$$Ga was evaluated to be around 4.7 b in many nuclear data libraries. On the other hand, it was evaluated to be 3.71 b in JENDL-4.0. Since these cross section data were obtained by the activation measurement with a monitor foil to determine the absolute value of cross section, data depend on the monitor foil adopted in the measurement. In this work, we measured the thermal neutron capture cross section of $$^{71}$$Ga with a few monitor foils. In the experiment, neutrons decelerated in concrete shield were irradiated with a sample with $$^{71}$$Ga foil and $$^{197}$$Au and $$^{55}$$Mn monitor foils. A covariance analysis was performed to obtain the off-diagonal weighted mean of the results determined with the two monitor reactions. As a result, the thermal neutron capture cross section of $$^{71}$$Ga was 4.05$$pm$$0.27 b and is close to the value of JENDL-4.0.

Journal Articles

CIELO collaboration summary results; International evaluations of neutron reactions on uranium, plutonium, iron, oxygen and hydrogen

Chadwick, M. B.*; Capote, R.*; Trkov, A.*; Herman, M. W.*; Brown, D. A.*; Hale, G. M.*; Kahler, A. C.*; Talou, P.*; Plompen, A. J.*; Schillebeeckx, P.*; et al.

Nuclear Data Sheets, 148, p.189 - 213, 2018/02

 Times Cited Count:8 Percentile:4(Physics, Nuclear)

The CIELO collaboration has studied neutron cross sections on nuclides that significantly impact criticality in nuclear facilities - $$^{235}$$U, $$^{238}$$U, $$^{239}$$Pu, $$^{56}$$Fe, $$^{16}$$O and $$^{1}$$H - with the aim of improving the accuracy of the data and resolving previous discrepancies in our understanding. This multi-laboratory pilot project, coordinated via the OECD/NEA Working Party on Evaluation Cooperation (WPEC) Subgroup 40 with support also from the IAEA, has motivated experimental and theoretical work and led to suites of new evaluated libraries that accurately reflect measured data and also perform well in integral simulations of criticality. This report summarizes our results and outlines plans for the next phase of this collaboration.

Journal Articles

Rock mass property evaluation based on the borehole wall images taken by using an ultrasonic scanner (USS)

Otsuka, Yasunori*; Ishikawa, Takanori*; Tajima, Katsuhiro*; Wada, Tetsu*; Aydan, $"O$mer*; Tokashiki, Naohiko*; Sato, Toshinori; Aoyagi, Kazuhei

Journal of Nepal Geological Society, 55(Special Issue), p.1 - 6, 2018/00

Ultrasonic wave reflection intensity of the wall of borehole drilled from bottom of the East Access Shaft in the Horonobe Underground Research Laboratory, Hokkaido, Japan, was obtained using an ultrasonic scanner (USS). In this paper, we compared results of USS observation with core logging data including core observation, optical digital scanner (ODS) observation, and result of Needle Penetration Index (NPI) tests. The results indicated that ultrasonic wave reflection intensity had a good correlation with other observation results. USS observation and NPI tests are useful techniques for determination of detailed rock mass classification.

Journal Articles

Dissemination of data measured at the CERN n_TOF facility

Dupont, E.*; Otsuka, Naohiko*; Harada, Hideo; Kimura, Atsushi; n_TOF Collaboration*; 224 of others*

EPJ Web of Conferences (Internet), 146, p.07002_1 - 07002_4, 2017/09

 Percentile:100

The n_TOF neutron time-of-flight facility at CERN is used for high quality nuclear data measurements from thermal energy up to hundreds of MeV. In line with the CERN open data policy, the n_TOF Collaboration takes actions to preserve its unique data, facilitate access to them in standardised format, and allow their re-use by a wide community in the fields of nuclear physics, nuclear astrophysics and various nuclear technologies. The present contribution briefly describes the n_TOF outcomes, as well as the status of dissemination and preservation of n_TOF final data in the international EXFOR library.

Journal Articles

Meeting nuclear data needs for advanced reactor systems

Harada, Hideo; Shibata, Keiichi; Nishio, Katsuhisa; Igashira, Masayuki*; Plompen, A.*; Hambsch, F.-J.*; Schillebeeckx, P.*; Gunsing, F.*; Ledoux, X.*; Palmiotti, G.*; et al.

NEA/NSC/WPEC/DOC(2014)446, 111 Pages, 2014/02

JAEA Reports

Simulator for materials testing reactors

Takemoto, Noriyuki; Sugaya, Naoto; Otsuka, Kaoru; Hanakawa, Hiroki; Onuma, Yuichi; Hosokawa, Jinsaku; Hori, Naohiko; Kaminaga, Masanori; Tamura, Kazuo*; Hotta, Koji*; et al.

JAEA-Technology 2013-013, 44 Pages, 2013/06

JAEA-Technology-2013-013.pdf:4.42MB

A real-time simulator for operating both a reactor and irradiation facilities of a materials testing reactor, Simulator of Materials Testing Reactors, was developed for understanding reactor behavior and upskilling in order to utilize for a nuclear human resource development and to promote partnership with developing countries which have a plan to introduce nuclear power plant. The simulator is designed based on the JMTR (Japan Materials Testing Reactor) and it simulates operation, irradiation tests and various kinds of anticipated operational transients and accident conditions caused by the reactor and irradiation facilities. The development of the simulator was sponsored by the Japanese government as one of the specialized projects of advanced research infrastructure in order to promote basic as well as applied researches. This report summarizes the simulation model, hardware specification and operation procedure of the simulator.

Journal Articles

Determination of resonance parameters and their covariances from neutron induced reaction cross section data

Schillebeeckx, P.*; Becker, B.*; Danon, Y.*; Guber, K.*; Harada, Hideo; Heyse, J.*; Junghans, A. R.*; Kopecky, S.*; Massimi, C.*; Moxon, M. C.*; et al.

Nuclear Data Sheets, 113(12), p.3054 - 3100, 2012/12

 Times Cited Count:58 Percentile:3.76(Physics, Nuclear)

Journal Articles

JENDL-4.0; A New library for innovative nuclear energy systems

Shibata, Keiichi; Iwamoto, Osamu; Nakagawa, Tsuneo; Iwamoto, Nobuyuki; Ichihara, Akira; Kunieda, Satoshi; Chiba, Satoshi; Katakura, Junichi; Otsuka, Naohiko*

Journal of the Korean Physical Society, 59(2), p.1046 - 1051, 2011/08

 Times Cited Count:8 Percentile:42.17(Physics, Multidisciplinary)

In JENDL-4, much emphasis is placed on the improvements of FP and MA data. For achieving this, new nuclear model codes POD and CCONE were developed, since experimental data are very scarce for those nuclei. The global coupled-channel optical model parameters, which were obtained in the wide mass region, were used for the evaluation of cross sections. Thermal cross sections of actinides were determined by carefully examining available experimental data. Special care was taken for the resonance region of $$^{235}$$U in order to reproduce measured criticalities and Na-void reactivities for U fueled fast-neutron cores. As for FP, resolved resonance parameters were updated for more than 100 nuclei. The cross sections of above the resonance region were evaluated by using the POD and CCONE codes. Fission product yield data were obtained from the ENDF/B-VII.0 data with some modifications. The new library, which contains neutron data for 406 nuclei, will be made available in 2010.

Journal Articles

Covariance evaluation for actinide nuclear data in JENDL-4

Iwamoto, Osamu; Nakagawa, Tsuneo; Chiba, Satoshi; Otsuka, Naohiko*

Journal of the Korean Physical Society, 59(2), p.1224 - 1229, 2011/08

 Times Cited Count:11 Percentile:34.66(Physics, Multidisciplinary)

Covariances of nuclear data in JENDL-4 have been evaluated. The covariance evaluations are basically based on available experimental data. The fission cross sections for 6 major actinides of $$^{233, 235, 238}$$U and $$^{239, 240, 241}$$Pu were evaluated simultaneously using experimental data of both cross sections and their ratios. The deduced covariance has correlations between the data of different nuclei. For minor actinide, covariances of the fission cross sections were obtained from evaluation using GMA code. For other many reaction cross sections, theoretical calculations with CCONE code were performed for cross section evaluations. The covariances were estimated using KALMAN code with sensitivities against model parameters. For resonance parameters and average number of fission neutrons, covariances were also evaluated.

Journal Articles

JENDL-4.0; A New library for nuclear science and engineering

Shibata, Keiichi; Iwamoto, Osamu; Nakagawa, Tsuneo*; Iwamoto, Nobuyuki; Ichihara, Akira; Kunieda, Satoshi; Chiba, Satoshi; Furutaka, Kazuyoshi; Otsuka, Naohiko*; Osawa, Takaaki*; et al.

Journal of Nuclear Science and Technology, 48(1), p.1 - 30, 2011/01

 Times Cited Count:851 Percentile:0.01(Nuclear Science & Technology)

The fourth version of Japanese Evaluated Nuclear Data Library has been produced. In the new library, much emphasis is placed on the improvements of fission product and minor actinoid data. Two nuclear model codes were developed to evaluate the cross sections of fission products and minor actinoids. Coupled-channel optical model parameters, which can be applied to wide mass and energy regions, were obtained for nuclear model calculations. Thermal cross sections of actinoids were determined by considering recent experimental data or by the systematics of neighboring nuclei. A simultaneous evaluation was performed for the fission cross sections of important uranium and plutonium isotopes above 10 keV. The data on FP were re-evaluated, and new evaluations were performed for 30 nuclides. The data on light elements and structural materials were partly re-evaluated. The new library was released as JENDL-4.0 in May 2010.

Journal Articles

JENDL actinoid file 2008

Iwamoto, Osamu; Nakagawa, Tsuneo; Otsuka, Naohiko*; Chiba, Satoshi; Okumura, Keisuke; Chiba, Go; Osawa, Takaaki*; Furutaka, Kazuyoshi

Journal of Nuclear Science and Technology, 46(5), p.510 - 528, 2009/05

JENDL Actinoid File 2008 (JENDL/AC-2008) was released in March 2008. It includes nuclear data for neutron-induced reactions for 79 nuclides from Ac ($$Z=89$$) to Fm ($$Z=100$$). The neutron energy range is $$10^{-5}$$ eV to 20 MeV. Almost all data for 61 actinoids in JENDL-3.3 were revised. New evaluations were performed for 17 nuclides which have half lives longer than 1 day. New comprehensive theoretical model code CCONE was widely used for the evaluation of cross sections and neutron emission spectra. Thermal cross sections for many nuclides were revised based on experimental data. Resonance parameters were readjusted to reproduce them. Simultaneous evaluations of fission cross sections were performed for six important nuclei. The least-squares fitting code GMA was used for evaluation of fission cross sections for minor actinoid. In this paper, we present the evaluation methods and results of the JENDL/AC-2008.

JAEA Reports

Covariances of resonance self-shielding factor and its temperature gradient for uncertainty evaluation of Doppler reactivity

Zukeran, Atsushi*; Chiba, Go; Otsuka, Naohiko*; Ishikawa, Makoto; Takano, Hideki*

JAEA-Research 2008-091, 162 Pages, 2009/02

JAEA-Research-2008-091-01.pdf:5.8MB
JAEA-Research-2008-091-02.pdf:45.78MB

Uncertainty of Doppler reactivity is theoretically formulated and then uncertainties of self-shielding factor and its temperature gradient due to errors of resonance parameters were evaluated from NJOY output. Sensitivity analysis was made for $$^{235}$$U, $$^{238}$$U, $$^{239}$$Pu and $$^{240}$$Pu of JENDL-3.3 based on JFS-3 70 group structure. Resultant sensitivity coefficients are provided for the uncertainty evaluation of Doppler reactivity.

Journal Articles

JENDL actinoid file 2008 and plan of covariance evaluation

Iwamoto, Osamu; Nakagawa, Tsuneo; Otsuka, Naohiko*; Chiba, Satoshi; Okumura, Keisuke; Chiba, Go

Nuclear Data Sheets, 109(12), p.2885 - 2889, 2008/12

 Times Cited Count:8 Percentile:44.04(Physics, Nuclear)

JENDL Actinoid File 2008 (JENDL/AC-2008) was released in March 2008. It provides nuclear data of neutron induced nuclear reactions for actinoid nuclides from Ac to Fm. The data for 62 nuclides in JENDL-3.3 were revised and newly evaluated data for 17 nuclides, which have a half-life longer than 1 day, were added. Nuclear reaction model code CCONE was widely used for the evaluations of cross sections and energy-angular distributions of secondary neutrons in fast energy region. Covariance data for the fission and capture cross sections and the number of neutrons per fission will be evaluated for important nuclides in the JENDL/AC-2008. The evaluation methods and the results will be presented and the plan of the covariance evaluations also will be mentioned.

Journal Articles

Toward the fourth version of Japanese Evaluated Nuclear Data Library (JENDL-4)

Shibata, Keiichi; Iwamoto, Osamu; Ichihara, Akira; Iwamoto, Nobuyuki; Kunieda, Satoshi; Otsuka, Naohiko*; Fukahori, Tokio; Nakagawa, Tsuneo; Katakura, Junichi

Proceedings of 16th Pacific Basin Nuclear Conference (PBNC-16) (CD-ROM), 6 Pages, 2008/10

Evaluated nuclear data play an important role in nuclear engineering. After we released the first version of Japanese Evaluated Nuclear Data Library JENDL-1 about 30 years ago, JENDL has been revised several times by considering the feedback from users and recent experimental data. JENDL-3.3, which was released in 2002, is being used in various fields, and its reliability has been confirmed. We are developing JENDL-4 for innovative reactors with much emphasis on the improvements of FP and MA data. Nuclear model codes were developed. The actinide data were already released as JENDL Actinoid File 2008. The complete library JENDL-4 will be made available in FY2009.

Journal Articles

Development of JENDL actinoid file

Iwamoto, Osamu; Nakagawa, Tsuneo; Otsuka, Naohiko*; Chiba, Satoshi; Okumura, Keisuke; Chiba, Go

Proceedings of International Conference on the Physics of Reactors, Nuclear Power; A Sustainable Resource (PHYSOR 2008) (CD-ROM), 8 Pages, 2008/09

Nuclear data for neutron induced reactions with actinides from Ac to Fm have been evaluated for JENDL Actinoid File (JENDL/AC). Almost all data in JENDL-3.3 have been updated based on available experimental data and using the newly developed theoretical model code CCONE. Integral benchmark tests for fission reactors are in progress using preliminary versions of JENDL/AC. The JENDL/AC will be released in 2008.

JAEA Reports

ERRORF; A Code to calculate covariance of self-shielding factor and its temperature gradient

Otsuka, Naohiko*; Zukeran, Atsushi*; Takano, Hideki*; Chiba, Go; Ishikawa, Makoto

JAEA-Data/Code 2008-012, 17 Pages, 2008/06

JAEA-Data-Code-2008-012.pdf:1.31MB

A computer code, ERRORF, was developed for calculation of covariance of self-shielding factor and its temperature gradient. This code is based on several modules. With this code, covariance of self-shielding factor and its temperature gradient can be calculated from evaluated nuclear library in the ENDF format.

Journal Articles

Recent advances in the JENDL project

Shibata, Keiichi; Nakagawa, Tsuneo; Fukahori, Tokio; Iwamoto, Osamu; Ichihara, Akira; Iwamoto, Nobuyuki; Kunieda, Satoshi; Otsuka, Naohiko; Katakura, Junichi; Watanabe, Yukinobu*; et al.

Proceedings of International Conference on Nuclear Data for Science and Technology (ND 2007), Vol.2, p.727 - 732, 2008/05

General- and special-purpose JENDL data files are being produced in cooperation with the Japanese Nuclear Data Committee. We have developed nuclear model codes to improve the quality of MA and FP data. In the FP region, we obtained global coupled-channel optical model parameters, which can be applied to neutron- and proton-induced reaction data up to 200 MeV. These parameters are used for statistical model calculation. Resolved resonance parameters of MA and FP nuclei were updated to improve the low-energy behavior of the cross sections by using recent measurements. As a follow-up of JENDL-3.3, which was released in 2002, covarainces of several nuclei were estimated for a study on ADS. Concerning special-purpose files, the compilation of the 2007 versions of JENDL High Energy File and Photonulcear Data Files is in the final stage.

Journal Articles

Covariance analyses of self-shielding factor and its temperature gradient for uranium-238 neutron capture reaction

Otsuka, Naohiko; Zukeran, Atsushi*; Takano, Hideki*; Chiba, Go; Ishikawa, Makoto

Journal of Nuclear Science and Technology, 45(3), p.195 - 210, 2008/03

 Times Cited Count:2 Percentile:78.3(Nuclear Science & Technology)

Covariances of the self-shielding factor and its temperature gradient for the uranium-238 neutron capture reaction have been evaluated from the resonance parameter covariance matrix and sensitivity of the self-shielding factor and its temperature gradient to microscopic nuclear data. The resonance parameters and their covariance matrix for uranium-238 were taken from JENDL-3.3, while the sensitivity coefficients were calculated by varying resonance parameters and temperature. A set of computer code modules has been developed for calculation of the sensitivity coefficients at numerous resonance levels. The present result shows that the correlation among resonance parameters yields a substantial contribution to the variances of the self-shielding factor and its temperature gradient. In addition to the variances of these quantities, their correlation matrices in the JFS-3 70 group structure are also obtained.

Journal Articles

Uranium-235 neutron capture cross section at keV energies

Otsuka, Naohiko; Nakagawa, Tsuneo; Shibata, Keiichi

Journal of Nuclear Science and Technology, 44(6), p.815 - 818, 2007/06

 Times Cited Count:2 Percentile:78.08(Nuclear Science & Technology)

The $$^{235}$$U neutron capture cross section was analyzedin the keV neutron energies by the least-squares method. The present analysis decreases the JENDL-3.3 cross sectionin the energy region from 20 to 200 keV and improves the C/E values of $$k_{rm eff}$$ for the BFS cores. The sodium void reactivity of the BFS cores is sensitiveto the capture cross sectionnear the upper limit of the resolved resonance region, where further investigation is necessary.

Journal Articles

Status of the JENDL general-purpose file

Shibata, Keiichi; Nakagawa, Tsuneo; Iwamoto, Osamu; Ichihara, Akira; Iwamoto, Nobuyuki; Kunieda, Satoshi; Fukahori, Tokio; Otsuka, Naohiko; Katakura, Junichi

Proceedings of American Nuclear Society Topical Meeting on Physics of Reactors (PHYSOR 2006) (CD-ROM), 10 Pages, 2006/09

no abstracts in English

31 (Records 1-20 displayed on this page)