Dimitriou, P.*; Dillmann, I.*; Singh, B.*; Piksaikin, V.*; Rykaczewski, K. P.*; Tain, J. L.*; Algora, A.*; Banerjee. K.*; Borzov, I. N.*; Cano-Ott, D.*; et al.
Nuclear Data Sheets, 173, p.144 - 238, 2021/03
-delayed neutron emission has been of interest since the discovery of nuclear fission. In nuclear power reactors, delayed-neutron data play a crucial role in reactor kinetics calculations and safe operation. -delayed neutron data also have a significant impact in the field of nuclear structure and astrophysics especially as nuclei farther away from stability are explored at the new generation of radioactive beam facilities. Several compilations of -decay half-lives and delayed-neutron emission probabilities are available, however, complete documentation of measurements and evaluation procedures is often missing for these properties. Efforts to address this gap in nuclear data and create an updated compilation and evaluation of -delayed neutron properties were undertaken under the auspices of the International Atomic Energy Agency (IAEA) which formed a Coordinated Research Project (CRP) on "Development of a Reference Database of Beta-delayed Neutron Emission Data". In this paper we summarize the work that was performed and present the results of the CRP.
Oizumi, Akito; Fukushima, Masahiro; Tsujimoto, Kazufumi; Chiba, Go*; Yamanaka, Masao*; Sano, Tadafumi*; Pyeon, C. H.*
KURNS Progress Report 2018, P. 38, 2019/08
In the nuclear transmutation system such as ADS, the nuclear data validation of MA is required to reduce the uncertainty caused by the nuclear data of MA. This study aims to measure the fission reaction rate ratios (FRRs) of Neptunium-237 (Np) or Americium-241 (Am) to Uranium-235 (U) by using a back-to-back (BTB) fission chamber in the KUCA built as a sub-critical core (k = 0.998) with the nuclear spallation neutron source. The result showed that the measured FRRs of Np/U and Am/U were 0.014 0.002 and 0.023 0.005, respectively. These measured values will be used for verification of evaluated nuclear data by conducting detailed analyses.
Iwamoto, Osamu; Shibata, Keiichi; Iwamoto, Nobuyuki; Chiba, Go*
Nihon Genshiryoku Gakkai-Shi ATOMO, 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.
Yamamoto, Akio*; Chiba, Go*; Kirimura, Kazuki*; Miki, Yosuke*; Yokoyama, Kenji
Nihon Genshiryoku Gakkai-Shi ATOMO, 60(4), p.241 - 245, 2018/04
no abstracts in English
Hirose, Kentaro; Nishio, Katsuhisa; Tanaka, Shoya*; Lguillon, 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
Fission-fragment mass distributions were measured for U, Np and Pu populated in the excitation-energy range from 10 to 60 MeV by multi-nucleon transfer channels in the reaction O + U at the JAEA tandem facility. Among them, the data for U and 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.
Suyama, Kenya; Kunieda, Satoshi; Fukahori, Tokio; Chiba, Go*
Nihon Genshiryoku Gakkai-Shi ATOMO, 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.
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
Lguillon, 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
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.
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
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.
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.
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 reliability.
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
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.
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.
Chiba, Go; Nagaya, Yasunobu; Mori, Takamasa
Journal of Nuclear Science and Technology, 48(8), p.1163 - 1169, 2011/08
The effective delayed neutron fraction 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 calculations, the concept of the generation-dependent importance functions is introduced to 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 calculations and that the use of the appropriate reactor property can reduce the required number of generations. An efficient procedure for the IFP-based calculations with the Monte Carlo method is also proposed.
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
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.
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
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.
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
We report on the event structure and double helicity asymmetry () of jet production in longitudinally polarized collisions at = 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 = -0.0014 0.0037 at the lowest bin and -0.0181 0.0282 at the highest bin. The measured is compared with the predictions that assume various distributions.
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
Transverse momentum distributions and yields for , and in collisions at = 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 collisions. We also present the scaling properties such as and scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.