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Journal Articles

Cutting-edge studies on nuclear data for continuous and emerging need, 8; Evolution of the nuclear data library JENDL

Iwamoto, Osamu; Shibata, Keiichi; Iwamoto, Nobuyuki; Chiba, Go*

Nippon Genshiryoku Gakkai-Shi, 60(6), p.357 - 361, 2018/06

Nuclear data library consists of the results of related studies on nuclear data. Nuclear data can show worth through utilization of the nuclear data library which is the outcome of the nuclear data study. As the last lecture over 8 serial ones, the Japanese nuclear data library JENDL is explained. Sections of "General purpose file and its history", "recent progress of special purpose file", and "international status of nuclear data library" are introduced and one of "prospect of JENDL and nuclear data study" is shown.

Journal Articles

Research and development roadmap for reactor physics 2017; Future of reactor physics projected by next generations

Yamamoto, Akio*; Chiba, Go*; Kirimura, Kazuki*; Miki, Yosuke*; Yokoyama, Kenji

Nippon Genshiryoku Gakkai-Shi, 60(4), p.241 - 245, 2018/04

no abstracts in English

Journal Articles

Role of multichance fission in the description of fission-fragment mass distributions at high energies

Hirose, Kentaro; Nishio, Katsuhisa; Tanaka, Shoya*; L$'e$guillon, R.*; Makii, Hiroyuki; Nishinaka, Ichiro*; Orlandi, R.; Tsukada, Kazuaki; Smallcombe, J.*; Vermeulen, M. J.; et al.

Physical Review Letters, 119(22), p.222501_1 - 222501_6, 2017/12

 Times Cited Count:26 Percentile:7.98(Physics, Multidisciplinary)

Fission-fragment mass distributions were measured for $$^{237-240}$$U, $$^{239-242}$$Np and $$^{241-244}$$Pu populated in the excitation-energy range from 10 to 60 MeV by multi-nucleon transfer channels in the reaction $$^{18}$$O + $$^{238}$$U at the JAEA tandem facility. Among them, the data for $$^{240}$$U and $$^{240,241,242}$$Np were observed for the first time. It was found that the mass distributions for all the studied nuclides maintain a double-humped shape up to the highest measured energy in contrast to expectations of predominantly symmetric fission due to the washing out of nuclear shell effects. From a comparison with the dynamical calculation based on the fluctuation-dissipation model, this behavior of the mass distributions was unambiguously attributed to the effect of multi-chance fission.

Journal Articles

Cutting-edge studies on nuclear data for continuous and emerging need, 1; Diversifying nuclear applications and need for the nuclear data

Suyama, Kenya; Kunieda, Satoshi; Fukahori, Tokio; Chiba, Go*

Nippon Genshiryoku Gakkai-Shi, 59(10), p.598 - 602, 2017/10

The nuclear data is the data on the reaction probability between the neutron and the nuclide in a narrow sense. However generally speaking, it is the data describing the physical change of the nuclide and the status of the nuclear ration. Since Japan had started the nuclear energy development, the nuclear data has been one of the most important technical development theme. Now, the nuclear data library of Japan, i.e., JENDL, is well recognized internationally because of the highest-accuracy and fully-furnished types of the included data. This serial lecture describes the significance and the status of the nuclear data development, the international trend, and the direction of the future development.

Journal Articles

Simultaneous measurement of neutron-induced fission and capture cross sections for $$^{241}$$Am at neutron energies below fission threshold

Hirose, Kentaro; Nishio, Katsuhisa; Makii, Hiroyuki; Nishinaka, Ichiro*; Ota, Shuya*; Nagayama, Tatsuro*; Tamura, Nobuyuki*; Goto, Shinichi*; Andreyev, A.; Vermeulen, M. J.; et al.

Nuclear Instruments and Methods in Physics Research A, 856, p.133 - 138, 2017/06

 Times Cited Count:3 Percentile:49.25(Instruments & Instrumentation)

Journal Articles

Fission fragments mass distributions of nuclei populated by the multinucleon transfer channels of the $$^{18}$$O + $$^{232}$$Th reaction

L$'e$guillon, R.; Nishio, Katsuhisa; Hirose, Kentaro; Makii, Hiroyuki; Nishinaka, Ichiro*; Orlandi, R.; Tsukada, Kazuaki; Smallcombe, J.*; Chiba, Satoshi*; Aritomo, Yoshihiro*; et al.

Physics Letters B, 761, p.125 - 130, 2016/10

 Times Cited Count:27 Percentile:6.1(Astronomy & Astrophysics)

JAEA Reports

Proceedings of the International Conference on Physics of Reactors (PHYSOR 2014); September 28-October 3, 2014, Kyoto, Japan

Suyama, Kenya; Sugawara, Takanori; Tada, Kenichi; Chiba, Go*; Yamamoto, Akio*

JAEA-Conf 2014-003, 76 Pages, 2015/03


Japan Atomic Energy Agency organized an international conference PHYSOR 2014 on the reactor physics which is one of basic researches in the nuclear engineering, in cooperation with Research Reactor Institute of Kyoto University. PHYSOR is the world's largest scale international conference in the reactor physics field. It originates in the conference held in Marseille, France in 1990, which originally had been organized in the United States as a Physics of Reactors Topical Meeting of the reactor physics division of the American Nuclear Society every two years. More than 500 papers had been submitted and finally 472 papers were presented in the conference after the paper review process. This report contains the presented papers, which the PHYSOR organizing committee has decided to publish in an official JAEA report with the permission by authors, except for several selected papers to be published in the Journal of Nuclear Science and Technology of the Atomic Energy Society of Japan.

Journal Articles

Proposal of a plutonium burner system based on HTGR with high proliferation resistance

Fukaya, Yuji; Goto, Minoru; Ohashi, Hirofumi; Tachibana, Yukio; Kunitomi, Kazuhiko; Chiba, Satoshi*

Journal of Nuclear Science and Technology, 51(6), p.818 - 831, 2014/06


 Times Cited Count:15 Percentile:14.54(Nuclear Science & Technology)

A plutonium burner HTGR concept of "Clean Burn" has been investigated based on the experience with the HTTR construction and operation, and the GTHTR300 design. The concept aims at effective and safe consumption of the surplus plutonium from LWR spent fuel once through. The Clean Burn employs IMF that can be fabricated without a need to mix the plutonium with uranium. In addition, the incineration of the plutonium can be performed effectively without plutonium generation from the matrix and the reactivity defect. The IMF is also made into a highly stable form to keep fuel integrity and geological disposal stability. The particular fabrication system and the stable form make the IMF more proliferation resistant than the conventional LWR-MOX fuel. This advantage is attractive to the Japanese nuclear fuel cycle policy. Moreover, the Clean Burn has naturally safe feature because based on HTGR concept. A detailed investigation have shown that the proposed concept is effective and promising.

JAEA Reports

Development of a standard data base for FBR core design, 14; Analyses of extensive FBR core characteristics based on JENDL-4.0

Sugino, Kazuteru; Ishikawa, Makoto; Numata, Kazuyuki*; Iwai, Takehiko*; Jin, Tomoyuki*; Nagaya, Yasunobu; Hazama, Taira; Chiba, Go*; Yokoyama, Kenji; Kugo, Teruhiko

JAEA-Research 2012-013, 411 Pages, 2012/07


Aiming at evaluating the core design prediction accuracy of fast reactors, various kinds of fast reactor core experiments/tests have been analyzed with the Japan's latest evaluated nuclear data library JENDL-4.0. Totally 643 characteristics of reactor physics experiments/tests and irradiation tests performed using the critical facilities: ZPPR, FCA, ZEBRA, BFS, MASURCA, ultra-small cores of LANL and power plants: SEFOR, Joyo, Monju were dealt. In analyses, a standard scheme/method for fast reactor cores was applied including detailed or precise calculations for best estimation. In addition, results of analyses were investigated from the viewpoints of uncertainties caused by experiment/test, analytical modeling and cross-section data in order to synthetically evaluate the consistency among different cores and characteristics. Further, by utilizing these evaluations, prediction accuracy of core characteristics were evaluated for fast power reactor cores that are under designing in the fast reactor cycle technology development (FaCT) project.

JAEA Reports

Uncertainty quantification of Doppler coefficient for MONJU

Chiba, Go*; Hazama, Taira; Kinjo, Hidehito*; Nishi, Hiroshi; Suzuki, Takayuki

JAEA-Research 2011-034, 42 Pages, 2011/12


Uncertainty of Doppler coefficient is quantified for a Monju core, reflecting present knowledge. Various uncertainty sources are evaluated: (1) Nuclear data and numerical method, (2) Fission product nuclear data, (3) Control rod position, (4) Approximated treatment of temperature dependence, (5) Averaged fuel temperature, (6) Approximated treatment of temperature spatial distribution, etc. Resulting uncertainty for Doppler coefficient is estimated at 11.7% for the 2 $$sigma$$ reliability.

Journal Articles

Benchmark calculations of sodium-void experiments with uranium fuels at the fast critical assembly FCA

Fukushima, Masahiro; Kitamura, Yasunori; Kugo, Teruhiko; Yamane, Tsuyoshi; Ando, Masaki; Chiba, Go; Ishikawa, Makoto; Okajima, Shigeaki

Progress in Nuclear Science and Technology (Internet), 2, p.306 - 311, 2011/10

Journal Articles

Sensitivity analysis for higher order Legendre coefficients of elastic scattering matrices

Chiba, Go

JAEA-Conf 2011-002, p.217 - 222, 2011/09

We perform a sensitivity analysis focusing on higher order Legendre coefficients of elastic scattering matrices. Through the sensitivity analysis, it is found that an attention should be paid to the kind of multi-group cross sections used for library effect calculations. Non-negligible library effects are observed in higher order Legendre coefficients of elastic scattering matrices of uranium-238 and iron-56 between JENDL-4.0 and other modern nuclear data files. It is concluded that higher order Legendre coefficients should be accounted for if accurate estimation of a library effect is required.

Journal Articles

Sensitivity analysis for curium isotope concentrations of light water reactor mixed-oxide burned fuel

Chiba, Go; Ishikawa, Makoto

JAEA-Conf 2011-002, p.211 - 216, 2011/09

With a help of the depletion perturbation theory, sensitivities of curium isotope concentrations to nuclear data are calculated for light water reactor mixed-oxide burned fuel. Through the present study, phenomenon of the curium isotope generations during a reactor operation is well understood. In addition, important nuclear data for accurate prediction of the curium isotope concentrations are specified. These information may be helpful to investigate a cause of discrepancy between experimental and calculation values for the curium isotope concentrations.

Journal Articles

On effective delayed neutron fraction calculations with iterated fission probability

Chiba, Go; Nagaya, Yasunobu; Mori, Takamasa

Journal of Nuclear Science and Technology, 48(8), p.1163 - 1169, 2011/08

 Times Cited Count:3 Percentile:69.29(Nuclear Science & Technology)

The effective delayed neutron fraction $$beta_{eff}$$ can be accurately calculated with the continuous-energy Monte Carlo method using the iterated fission probability (IFP) if the sufficiently large number of generations is considered. In order to deterministically quantify the required number of generations in the IFP-based $$beta_{eff}$$ calculations, the concept of the generation-dependent importance functions is introduced to $$beta_{eff}$$ calculations. Furthermore, the most appropriate reactor property used in the IFP calculations, which reduces the required number of generations, is theoretically derived. Through numerical calculations, it is shown that the several generations are required in the IFP-based $$beta_{eff}$$ calculations and that the use of the appropriate reactor property can reduce the required number of generations. An efficient procedure for the IFP-based $$beta_{eff}$$ calculations with the Monte Carlo method is also proposed.

Journal Articles

JENDL-4.0 integral testing for fission systems

Okumura, Keisuke; Sugino, Kazuteru; Chiba, Go; Nagaya, Yasunobu; Yokoyama, Kenji; Kugo, Teruhiko; Ishikawa, Makoto; Okajima, Shigeaki

Journal of the Korean Physical Society, 59(2), p.1135 - 1140, 2011/08

 Times Cited Count:2 Percentile:77.51(Physics, Multidisciplinary)

The new version of Japanese evaluated nuclear data library, JENDL-4.0, is tested with integral data of fission systems. This data testing is carried out with a wide range of integral data including the critical benchmarks preserved in the International Handbook of Evaluated Criticality Safety Benchmark Experiments, the experimental data of MOX-fueled critical assemblies relating to the plutonium aging effect, the critical data of various fast critical assemblies and the fast reactors JOYO and MONJU, and the post-irradiation examination data of the pressurized-water reactor Takahama-3 and the fast reactor JOYO. The benchmark calculations are performed with a continuous-energy Monte Carlo code MVP-II or a sophisticated deterministic neutron transport code system. Benchmark calculations with other libraries, such as JENDL-3.3, ENDF/B-VII.0 and JEFF-3.1, are also performed, and differences in performance of these libraries are discussed with a help of sensitivity profiles to nuclear data.

Journal Articles

Development of a unified cross-section set ADJ2010 based on adjustment technique for fast reactor core design

Sugino, Kazuteru; Ishikawa, Makoto; Yokoyama, Kenji; Nagaya, Yasunobu; Chiba, Go; Hazama, Taira; Kugo, Teruhiko; Numata, Kazuyuki*; Iwai, Takehiko*; Jin, Tomoyuki*

Journal of the Korean Physical Society, 59(2), p.1357 - 1360, 2011/08

 Times Cited Count:5 Percentile:57(Physics, Multidisciplinary)

In order to improve the prediction accuracy of core performances in the fast reactor core design study, the unified cross-section set has been developed in Japan. The unified cross-section set, which combines a wide range of integral experimental information with differential nuclear data, is produced by using the cross-section adjustment technique based on the Bayesian parameter-estimation theory. A new set ADJ2010 is currently under development. The present paper describes the results of the cross-section adjustment for ADJ2010 which is based on the JENDL-4.0 data. The evaluation of the core design accuracy for a commercial power fast reactor core is also discussed. ADJ2010 will be released soon and will be expected to be utilized for core design of future fast reactors.

Journal Articles

Event structure and double helicity asymmetry in jet production from polarized $$p + p$$ collisions at $$sqrt{s}$$ = 200 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Y.*; Al-Bataineh, H.*; Alexander, J.*; Aoki, K.*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review D, 84(1), p.012006_1 - 012006_18, 2011/07

 Times Cited Count:22 Percentile:29.11(Astronomy & Astrophysics)

We report on the event structure and double helicity asymmetry ($$A_{LL}$$) of jet production in longitudinally polarized $$p + p$$ collisions at $$sqrt{s}$$ = 200 GeV. Photons and charged particles were measured by the PHENIX experiment. Event structure was compared with the results from PYTHIA event generator. The production rate of reconstructed jets is satisfactorily reproduced with the next-to-leading-order perturbative QCD calculation. We measured $$A_{LL}$$ = -0.0014 $$pm$$ 0.0037 at the lowest $$P_T$$ bin and -0.0181 $$pm$$ 0.0282 at the highest $$P_T$$ bin. The measured $$A_{LL}$$ is compared with the predictions that assume various $$Delta G(x)$$ distributions.

Journal Articles

Identified charged hadron production in $$p + p$$ collisions at $$sqrt{s}$$ = 200 and 62.4 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06

 Times Cited Count:141 Percentile:0.63(Physics, Nuclear)

Transverse momentum distributions and yields for $$pi^{pm}, K^{pm}, p$$, and $$bar{p}$$ in $$p + p$$ collisions at $$sqrt{s}$$ = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different $$sqrt{s}$$ collisions. We also present the scaling properties such as $$m_T$$ and $$x_T$$ scaling and discuss the mechanism of the particle production in $$p + p$$ collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.

Journal Articles

Application of the hierarchical domain decomposition boundary element method to the simplified P$$_{3}$$ equation

Chiba, Go

Annals of Nuclear Energy, 38(5), p.1033 - 1038, 2011/05

 Times Cited Count:4 Percentile:61.6(Nuclear Science & Technology)

In the present paper, the hierarchical domain decomposition boundary element method (HDD-BEM), which has been developed to solve the diffusion equation, is applied to the simplified P$$_{3}$$ (SP$$_{3}$$) equation. The solution methodology of the HDD-BEM for the SP$$_{3}$$ equation is provided in the present paper. A computer program ABEMIE based on the HDD-BEM is developed, and a two-dimensional one-group anisotropic scattering benchmark problem is solved with it to verify the present HDD-BEM for the SP$$_{3}$$ equation. Through numerical benchmarking, it is shown that the present method results in good agreement with the solution obtained by using the existing SP$$_{N}$$ solver based on the finite element method for both eigenvalue and neutron flux distribution. This benchmark result suggests that the HDD-BEM can be an efficient solver for the SP$$_{N}$$ equation.

Journal Articles

Sensitivity analysis for neutron multiplication parameters of accelerator driven subcritical system

Chiba, Go; Nishihara, Kenji; Endo, Tomohiro*

Proceedings of International Conference on Mathematics and Computational Methods applied to Nuclear Science and Engineering (MC 2011) (CD-ROM), 12 Pages, 2011/05

Sensitivity calculations are carried out for some neutronic parameters on neutron multiplication in subcritical systems. Sensitivities of the subcriticality multiplication rate $$k$$$$_{rm sub}$$ and the generation-wise neutron multiplication rate $$k$$$$_{i}$$, which is a new neutronic parameter proposed in the present paper, are calculated, and these sensitivities are compared with the $$k$$$$_{rm eff}$$ sensitivities which have been conventionally used for sensitivity works. The present sensitivity calculations show that the sensitivities of $$k$$$$_{rm sub}$$ and $$k$$$$_{i}$$ in small values of $$i$$ are significantly different from the $$k_{eff}$$ sensitivities. This result indicates that the sensitivity analyses focusing only on the solution of the eigenvalue equation cannot provide full information on the core properties of subcritical systems, and that the sensitivities of the other neutronic parameters describing real neutron multiplication are essential.

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