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U and 
ThFilipescu, D.*; Gheorghe, I.*; Goriely, S.*; Nishio, Katsuhisa; Utsunomiya, Hiroaki*; Suzaki, Fumi; Hirose, Kentaro; 10 of others*
Physical Review C, 109(4), p.044602_1 - 044602_23, 2024/04
Tada, Kenichi; Nagaya, Yasunobu; Taninaka, Hiroshi; Yokoyama, Kenji; Okita, Shoichiro; Oizumi, Akito; Fukushima, Masahiro; Nakayama, Shinsuke
Journal of Nuclear Science and Technology, 21 Pages, 2023/04
Times Cited Count：6 Percentile：99.12(Nuclear Science & Technology)The new version of the Japanese evaluated nuclear data library, JENDL-5, was released in December 2021. This paper demonstrates the validation of JENDL-5 for fission reactor applications. Benchmark calculations are performed with the continuous-energy Monte Carlo codes MVP and MCNP and the deterministic code system MARBLE. The benchmark calculation results indicate that the performance of JENDL-5 for fission reactor applications is better than that of the former library JENDL-4.0.
Ono, Masahiro*; Uchibori, Akihiro; Okano, Yasushi; Takata, Takashi*
JAEA-Testing 2022-004, 193 Pages, 2023/03
JAEA-Testing-2022-004.pdf:3.31MB
A computer code TRACER (Transport phenomena of Radionuclides for Accident Consequence Evaluation of Reactor) version 2.4.1 has been developed to evaluate species and quantities of fission products (FPs) released into cover gas due to a fuel pin failure in an LMFBR. The TRACER version 2.4.1 includes the models related to NUREG-0772 and also new or modified computational program codes in order to possess a new function shown below, and partial modify of coefficient of FP transition model between coolant and cover gas. This manual includes manual conventions for TRACER Version 2.3, addition of reference such as formula, improvement of explanation of input file creation method, addition of improvement of NUREG-0772 model added to TRACER code, modification of figure of sample analysis performed in appendix. It includes modifications and additions of sample analysis.
Metoki, Naoto
Hamon, 32(4), p.173 - 176, 2022/11
Nuclear spin polarization and the hyperfine splitting of Nd compounds were studied by means of neutron scattering. We can determine the magnetic moment from the unusual upturn of the antiferromagnetic Bragg intensities due to the interference with the nuclear spin contribution and the magnetic moment.
Nakayama, Shinsuke; Furutachi, Naoya; Iwamoto, Osamu; Watanabe, Yukinobu*
NEA/NSC/R(2020)4 (Internet), p.345 - 349, 2022/10
Long-lived fission products (LLFPs) generated in nuclear reactors are strongly desired to be converted to stable or short-lived nuclides. Recently, it has been considered to transmute LLFPs by spallation reactions with high energy particles, and some experimental studies revealed that spallation reaction cross-sections induced by deuteron are larger than proton-induced ones. These results suggest the possibility that nuclear transmutation of LLFPs using deuteron beams is more efficient than one using proton beams. On the other hand, we have been developing a code system dedicated for deuteron-induced reactions, called DEURACS. DEURACS has been originally developed to contribute to the design of deuteron accelerator neutron sources. In the present study, we apply DEURACS to calculation of deuteron-induced spallation reactions on LLFPs. Through comparison with measured data, the applicability of DEURACS will be discussed.
Al
and Nd
Pd
Ge
Metoki, Naoto; Shibata, Kaoru; Matsuura, Masato*; Kitazawa, Hideaki*; Suzuki, Hiroyuki*; Yamauchi, Hiroki; Hagihara, Masato; Frontzek, M. D.*; Matsuda, Masaaki*
Journal of the Physical Society of Japan, 91(5), p.054710_1 - 054710_6, 2022/05
Times Cited Count：0 Percentile：0(Physics, Multidisciplinary)Hyperfine splitting of Nd nuclei in NdPdAl has been studied by means of high-resolution neutron spectroscopy. We observed inelastic peaks at 
eV coming from the hyperfine splitting in the magnetically ordered phase due to the hyperfine interactions between Nd nuclei (
=7/2) and the 4
electrons with 
ground state composed of mainly 
. At very low temperatures, nuclear spin of Nd is polarized with increasing occupation probability of low energy levels and contributes to the enhancement of the antiferromagnetic Bragg intensities: the elastic non-spin-flip channel is dominant. As an application of this phenomenon, we determined the Nd moment and hyperfine splitting from the temperature dependence of an antiferromagnetic Bragg intensities for NdPdGe.
Iwamoto, Hiroki
JAEA-Conf 2021-001, p.24 - 29, 2022/03
Various spallation reaction models have been developed for the use of neutronic and shielding design of high-energy accelerator facilities such as J-PARC and ADS. However, their complicated theory for the de-excitation process has made improving their prediction accuracy difficult. In particular, it has been pointed out that the conventional models underestimate the yield of the spallation products produced from the fission reaction. This work has thus aimed to model the probability was described using a simpler, systematic expression, and then confirmed to predict fission cross sections for various incident energies and target nuclei with improved accuracy [1]. In this presentation, we will present the description of our model and research results. [1] H. Iwamoto and S. Meigo, "Unified description of the fission probability for highly excited nuclei", Journal of Nuclear Science and Technology, 56:2, 160-171 (2019).
Aritomo, Yoshihiro*; Iwamoto, Akira*; Nishio, Katsuhisa; Ota, Masahisa*
Physical Review C, 105(3), p.034604_1 - 034604_8, 2022/03
Times Cited Count：2 Percentile：49.92(Physics, Nuclear)
O + 
NpTanaka, Shoya*; Hirose, Kentaro; Nishio, Katsuhisa; Kean, K. R.*; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Aritomo, Yoshihiro*
Physical Review C, 105(2), p.L021602_1 - L021602_5, 2022/02
Times Cited Count：2 Percentile：30.99(Physics, Nuclear)Iwamoto, Hiroki; Meigo, Shinichiro; Nakano, Keita; Yee-Rendon, B.; Katano, Ryota; Sugawara, Takanori; Nishihara, Kenji; Sasa, Toshinobu; Maekawa, Fujio
JAEA-Research 2021-012, 58 Pages, 2022/01
JAEA-Research-2021-012.pdf:7.23MB
A radiation shielding analysis was performed for the structure located above the spallation target of an accelerator-driven system (ADS), assuming one cycle of an 800 MW thermal and 30 MW beam power operation. In this analysis, the Monte Carlo particle transport code PHITS and the activation analysis code DCHAIN-PHITS were used. The structures to be analyzed are a beam duct above the target, a beam transport room located above the ADS reactor vessel, beam transport equipment, and the room ceiling. For each structure, the radiation doses and radioactivities during and after the operation were estimated. Furthermore, the shielding structure of the ceiling was determined. As a result, it was found that the radiation dose at the site boundary would be sufficiently lower than the legal limit by applying the determined shielding structure. Moreover, under the condition of this study, it was shown that the effective dose rate around the beam transport equipment positioned above the target after the operation exceeded 10 mSv/h, and that the maintenance and replacement of the equipment in the room would require remote handling.
Ir M
ssbauer spectroscopic parameters of Vaska's complexes and their oxidative adductsKaneko, Masashi; Nakashima, Satoru*
Inorganic Chemistry, 60(17), p.12740 - 12752, 2021/09
Times Cited Count：3 Percentile：31.46(Chemistry, Inorganic & Nuclear)In the present study, density functional theory (DFT) calculation was applied to Vaska's complexes of formula 
-[IrCl(CO)(PPh
)
], and their oxidative adducts with small molecules (YZ) including H, i.e., -[IrCl(YZ)(CO))(PPh)], to successfully correlate the electronic states of the complexes with the corresponding Ir Mssbauer spectroscopic parameters. After confirming the reproducibility of the DFT methods for elucidating the equilibrium structures and Ir Mssbauer isomer shifts of the octahedral Ir complexes, the isomer shifts and quadrupole splitting values of Vaska's complexes and their oxidative adducts were calculated. A bond critical point analysis revealed that the tendency in the isomer shifts was correlated with the strength of the covalent interaction in the coordination bonds. In an electric field gradient (EFG) analysis of the oxidative adducts, the sign of the principal axis was found to be positive for the complex with YZ = Cl and negative for the complex with YZ = H. This reversal of the sign of the EFG principal axis was caused by the difference in the electron density distribution for the coordination bonds between Ir and YZ, according to a density of states analysis.
Hidaka, Akihide
Fission Product Behavior under Severe Accident, p.85 - 88, 2021/05
no abstracts in English
Schmitt, C.*; Lemasson, A.*; Schmidt, K.-H.*; Jhingan, A.*; Biswas, S.*; Kim, Y. H.*; Ramos, D.*; Andreyev, A. N.; Curien, D.*; Ciemala, M.*; et al.
Physical Review Letters, 126(13), p.132502_1 - 132502_6, 2021/04
Times Cited Count：16 Percentile：83.29(Physics, Multidisciplinary)Okamura, Tomohiro*; Oizumi, Akito; Nishihara, Kenji; Nakase, Masahiko*; Takeshita, Kenji*
JAEA-Data/Code 2020-023, 32 Pages, 2021/03
JAEA-Data-Code-2020-023.pdf:1.67MB
Nuclear Material Balance code (NMB code) have been developed in Japan Atomic Energy Agency. The NMB code will be updated with the function of mass balance analysis at the backend process such as reprocessing, vitrification and geological disposal. In order to perform its analysis with high accuracy, it is necessary to expand the number of FP nuclides calculated in the NMB code. In this study, depletion calculation by ORIGEN code was performed under 3 different burn-up conditions such as spent uranium fuel from light water reactor, and nuclides were selected from 5 evaluation indexes such as mass and heat generation. In addition, the FP nuclides required to configure a simple burnup chain with the same calculation accuracy as ORIGEN in the NMB code was selected. As the result, two lists with different number of nuclides, such as "Detailed list" and a "Simplified list", were created.
Iwamoto, Hiroki
Kaku Deta Nyusu (Internet), (128), p.13 - 25, 2021/02
no abstracts in English
O+Np reactionVermeulen, M. J.; Nishio, Katsuhisa; Hirose, Kentaro; Kean, K. R.; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Tsekhanovich, I.*; Andreyev, A. N.; Ishizaki, Shoma*; et al.
Physical Review C, 102(5), p.054610_1 - 054610_11, 2020/11
Times Cited Count：5 Percentile：51.79(Physics, Nuclear)Aritomo, Yoshihiro*; Miyamoto, Yuya*; Nishio, Katsuhisa
Nihon Butsuri Gakkai-Shi, 75(10), p.631 - 636, 2020/10
no abstracts in English
Kanamura, Shohei*; Takahashi, Yuya*; Omori, Takashi*; Nohira, Toshiyuki*; Sakamura, Yoshiharu*; Matsumura, Tatsuro
Denki Kagaku, 88(3), p.289 - 290, 2020/09
no abstracts in English
Sasaki, Yuji
Kagaku Kogaku, 84(9), p.425 - 427, 2020/09
The reduction of waste volume and hazardous substance though separation methods concerning atomic energy must be requested. As disposal methods or temporary measures, geological disposal, transmutation and interim storage are proposed. In order to perform effectively the disposal methods, the development of separation method of aimed elements is indispensable. Here, the new separation method of U and Pu from spent nuclear fuel and minor actinide separation and fission products from high level radioactive waste are explained.
P
rez S
nchez, R.*; Jurado, B.*; Mot, V.*; Roig, O.*; Dupuis, M.*; Bouland, O.*; Denis-Petit, D.*; Marini, P.*; Mathieu, L.*; Tsekhanovich, I.*; et al.
Physical Review Letters, 125(12), p.122502_1 - 122502_5, 2020/09
Times Cited Count：14 Percentile：71.69(Physics, Multidisciplinary)