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Tada, Kenichi; Nagaya, Yasunobu; Kunieda, Satoshi
no journal, ,
JAEA has been developing the nuclear data processing system FRENDY (FRom Evaluated Nuclear Data librarY to any application). The first goal of the development of FRENDY is generation function of the nuclear data library for the continuous energy Monte Carlo calculation code. To generate the nuclear data library, four procedures, i.e., (1) Generation of point wise cross section, (2) generation of the probability table, (3) processing the thermal scattering law data, and (4) generation of the nuclear data library, are required. In this presentation, generation of the ACE file which is the nuclear data library for the continuous energy Monte Carlo code is described. To verify FRENDY, the K
values which is using the ACE file which is processed by FRENDY are compared with that by NJOY99. The difference of the K values are less than 0.05%. This result indicates that FRENDY appropriately generate the ACE file.
Nakayama, Shinsuke
no journal, ,
Toward development of an activation cross section file, we evaluated neutron cross sections on copper isotopes in the incident energy range from 50 keV to 20 MeV. Although copper is important material, the evaluated values of activation cross sections on copper isotopes have not been updated for about thirty years, and some large discrepancies can be seen between the evaluated values and the recently measured ones. In the present study, therefore, we aimed to improve accuracy of activation cross sections. We used the CCONE code for nuclear reaction calculation. Direct component was calculated by the dispersive coupled-channel optical model and the distorted wave Born approximation. Pre-equilibrium and compound components were calculated by the two component exciton model and the Hauser-Feshbach model, respectively. The present evaluation results reproduced the existing measured data better than the evaluated data of JENDL-4.0.
Nakano, Hiroko; Hirota, Noriaki; Takeuchi, Tomoaki; Shibata, Hiroshi; Nemoto, Tadahiro*; Hanamoto, Yukio*; Tsuchiya, Kunihiko
no journal, ,
no abstracts in English
Maeda, Makoto; Ozu, Akira; Kureta, Masatoshi; Toh, Yosuke; Bogucarska, T.*; Crochemore, J.-M.*; Varasano, G.*; Pedersen, B.*
no journal, ,
no abstracts in English
Konno, Chikara; Tada, Kenichi
no journal, ,
The nuclear data library TENDL-2015 up to 200 MeV is being used as a standard nuclear data library worldwide, particularly in Europe. We found out the following three problems in the ENDF and ACE files in TENDL-2015 neutron sub-library; (1) no unresolved resonance data in most of the ACE files, (2) no secondary 
data in most of the ACE files, (3) No high-energy peaks in the capture reaction of a lot of the ENDF files. We examined effects of these problems and the followings were demonstrated; (1) insufficient self-shielding correction, (2) wrong spectra in neutron- coupling calculations and wrong DPA cross section data. Secondary data of the capture reaction and ACE files in TENDL-2015 neutron sub-library should be revised.
Cs neutron-capture cross-section as part of the ImPACT projectHales, B. P.; Nakamura, Shoji; Kimura, Atsushi; Iwamoto, Osamu
no journal, ,
There is currently a plan to measure the neutron-capture cross-section of 
Cs (half-life 2.3 million years), using the neutron beam at the Materials and Life science Facility (MLF) at J-PARC. In the course of measuring Cs, it is unavoidable that Cs (stable) will be an impurity within the sample. In order to derive high-quality Cs data, it is necessary to also measure Cs. We have measured the neutron-capture cross-section of Cs using ANNRI at the MLF at J-PARC, in the energy region from thermal to 1.5 keV, via the time-of-flight method. This measurement has better statistics and covers a wider energy range than previous measurements of Cs. Additionally, we have confirmed the misassignment of various resonances from previous experiments.
Morioka, Tatsuya; Sawazaki, Hiromasa; Uchida, Takenobu; Sato, Takeshi; Nakamura, Yoshihide; Shiotani, Hiroki; Kunogi, Kosuke
no journal, ,
Thermal natural convection occurred in Ar gas region between the inner and outer casing of the sodium pump in the past, which induces asymmetric circumferential temperature distribution on the casings. This thermal effect causes the contact of the pump shaft with the lower hydrostatic bearing, which places the bearing at risk for damage. This phenomenon strongly appears in long size pumps of sodium fast reactors. To prevent this risk for Monju primary sodium pump, convection prevention plates are installed between the inner and outer casing of the pump. Monju plant data indicates the plates decrease the circumferential temperature difference, and then no contact arose between the pump shaft and the bearing.
Yokoyama, Kenji; Takeda, Toshikazu*; Numata, Kazuyuki
no journal, ,
no abstracts in English
Furutachi, Naoya; Minato, Futoshi; Iwamoto, Osamu
no journal, ,
Nuclear reaction calculations using the statistical model require information of the nuclear level density. While the phenomenological models such as Fermi Gas model are often used to calculate the nuclear level density in usual nuclear data evaluations, reliability of such level density depends on parameter adjustments using experimental values. Therefore, development of microscopic calculation methods that does not depend on parameter adjustments is desired. One of the microscopic methods to calculate the nuclear level density is the combinatorial method that uses single-particle levels obtained from Hartree-Fock theory, and its reliability has been discussed through the reproducibility of the s-wave neutron resonance spacing 
. However, comparisons of cross sections with experiments are only preformed for (n,) reaction of some nuclei, and is still insufficient. Therefore, in this work, we calculate the nuclear level density using the combinatorial method, and apply it to the nuclear reaction calculations such as (n,) reaction and (n,2n) reaction calculations. The cross sections of these reactions adding to the s-wave neutron resonance spacing for stable nuclei are compared with the experiments systematically, and then the reliability of the nuclear level density is discussed.
Kawaguchi, Munemichi; Miyahara, Shinya; Uno, Masayoshi*
no journal, ,
no abstracts in English
Ozu, Akira; Maeda, Makoto; Komeda, Masao; Tobita, Hiroshi; Toh, Yosuke
no journal, ,
no abstracts in English
Nakao, Taro; Terada, Kazushi; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Osamu; Harada, Hideo; Igashira, Masayuki*; Katabuchi, Tatsuya*; Hori, Junichi*
no journal, ,
In the reaction cross section measurements using accelerator facilities, the total amount of the target particles is important. In case of the radioactive samples, however, the absolute amount is not always determined accurately. In addition, as the radioactive samples are required to be sealed properly for the safety reason, the non-destructive quantitative method is required. This presentation will report about the developments of the calorimetoric method for determination of amount of radioactive samples. Present study includes the result of "Research and Development for accuracy improvement of neutron nuclear data on minor actinides" entrusted to the Japan Atomic Energy Agency by the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT).
TcIwamoto, Nobuyuki; Mizuyama, Kazuhito; Iwamoto, Osamu
no journal, ,
no abstracts in English
Am with ANNRI at J-PARCKimura, Atsushi; Nakamura, Shoji; Terada, Kazushi; Nakao, Taro; Harada, Hideo; Katabuchi, Tatsuya*; Igashira, Masayuki*; Takamiya, Koichi*; Fukutani, Satoshi*; Fujii, Toshiyuki*; et al.
no journal, ,
no abstracts in English
Am with ANNRI at J-PARCTerada, Kazushi; Nakao, Taro; Kimura, Atsushi; Nakamura, Shoji; Mizuyama, Kazuhito; Iwamoto, Nobuyuki; Iwamoto, Osamu; Harada, Hideo
no journal, ,
Measurements of neutron capture cross sections of Am have been performed with Ge spectrometers at ANNRI in the J-PARC. We obtained capture cross sections of Am in neutron energy region from the thermal to 100 eV. The results were compared with previous measurements and evaluations.
Yamashita, Takuya; Sawada, Noriyoshi*
no journal, ,
Decontamination simulations were carried out using the restoration support system for environment "RESET" to provide to the national government and local governments information of decontamination effects and future dose rate necessary for forecasting the reconstruction plan of the difficult-to-return zone.
CsKawamura, Hideyuki; Furuno, Akiko; Kobayashi, Takuya; In, Teiji*; Nakayama, Tomoharu*; Ishikawa, Yoichi*; Miyazawa, Yasumasa*; Usui, Norihisa*
no journal, ,
Oceanic dispersion simulations include errors originated from source terms, oceanographic data, etc. In this study, the oceanic dispersion simulations were carried out with five oceanographic data in order to analyze an effect of oceanographic data on Cs dispersion and clarify Cs dispersion in the coastal area and the open ocean. The high-resolution simulation could well reproduce the observed Cs concentration in Fukushima Prefecture and it suggested that directly-released Cs into the ocean dispersed in the north-south direction during a few months after the Fukushima disaster. The relatively low-resolution simulations could reproduce main currents in the North Pacific and they suggested that the Kuroshio Extension played an important role on Cs transport from the coastal area to the open ocean. Moreover, it was demonstrated that Cs was transported from the mixed layer to the deeper layer 1 year after the Fukushima disaster.
-raysOmer, M.; Shizuma, Toshiyuki*; Hajima, Ryoichi*; Angell, C.*
no journal, ,
An elastic scattering experiment has been performed using 100% linearly polarized -rays generated by laser Compton backscattering at Duke University, NC, USA. Photons of energy of 2 MeV elastically scattered off uranium target were measured with high-purity Ge detectors. The results are used in the simulation study to improve the sensitivity of identifying isotopes by nuclear resonance fluorescence. Validation of the elastic scattering cross section of a polarized -rays is reported.
Serizawa, Hiroyuki; Osawa, Takahito; Oishi, Yuji*; Nemoto, Yoshiyuki; Kondo, Keietsu; Shohoji, Nobumitsu*; Kaji, Yoshiyuki
no journal, ,
A new reaction model for evaluating the activity of oxygen and hydrogen atoms of H
O molecules is proposed. The surprisingly high value of the activity implies that the production process of volatile metal hydroxides might be reconsidered.
Yamashita, Susumu; Uesawa, Shinichiro; Yoshida, Hiroyuki
no journal, ,
no abstracts in English