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Abe, Takumi; Oizumi, Akito; Nishihara, Kenji; Nakase, Masahiko*; Asano, Hidekazu*; Takeshita, Kenji*
Progress in Nuclear Science and Technology (Internet), 7, p.299 - 304, 2025/05
Currently, much research continues on stable energy sources that do not emit CO
in order to achieve a carbon-neutral and sustainable society. Nuclear energy is one of the such sources, and various new reactors and reprocessing technologies are being developed. In order to implement the nuclear fuel cycle with these technologies, a nuclear fuel cycle simulator is required to quantitatively evaluate various quantities, such as the distribution of nuclear fuel materials and the scale of waste loading. For this purpose, NMB4.0 was developed in collaboration with Tokyo Institute of Technology and Japan Atomic Energy Agency. This code calculates the material balance of 179 nuclides including actinides and fission products (FPs) from the front-end to the back-end and simulates the nuclear fuel cycle in an integrated manner. Unlike other nuclear fuel cycle simulators, the code is capable of performing precise back-end analyses such as the number of radioactive wastes and the scale of the geological repository considering heat generation of waste package under diverse nuclear energy scenario, and is an open source code that runs on Microsoft Excel. By these features, it is possible to quantitatively study nuclear energy utilization strategies with various stakeholders. The presentation will detail the numerical model used in NMB4.0.
Kokubun, Yuji; Hosomi, Kenji; Nagaoka, Mika; Seya, Natsumi; Inoue, Kazumi; Koike, Yuko; Uchiyama, Rei; Sasaki, Kazuki; Maehara, Yushi; Matsuo, Kazuki; et al.
JAEA-Review 2024-054, 168 Pages, 2025/03
JAEA-Review-2024-054.pdf:2.73MB
The Nuclear Fuel Cycle Engineering Laboratories conducts environmental radiation monitoring around the reprocessing plant in accordance with the "Safety Regulations for Reprocessing Plant of JAEA, Part IV: Environmental Monitoring". This report summarizes the results of environmental radiation monitoring conducted during the period from April 2023 to March 2024 and the results of dose calculations for the surrounding public due to the release of radioactive materials from the plant into the atmosphere and ocean. In the results of the above environmental radiation monitoring, several items were affected by radioactive materials emitted from the accident at the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Company, Incorporated (changed to Tokyo Electric Power Holdings, Inc. on April 1, 2016), which occurred in March 2011. In addition, environmental monitoring plan, analysis and measurement methods, monitoring data and their chronological change, meteorological data after statistical processing, status of radioactive waste release and evaluation results of the data over the normal range are included as appendices.
with geometrically frustrated orthogonal antiferromagnetic dimerMetoki, Naoto; Yamauchi, Hiroki; Hagihara, Masato; Watanuki, Ryuta*; Kawamura, Seiko; Kofu, Maiko*; Nakajima, Kenji; Matsuda, Masaaki*
Physical Review B, 111(10), p.104424_1 - 104424_9, 2025/03
Times Cited Count：0 Percentile：0.00(Materials Science, Multidisciplinary)Inelastic neutron scattering experiments were carried out to understand the unusual successive order in NdB with the frustrated Shatry-Sutherland (SS) lattice. The pseudo-quartet with 
and 
splits into four levels in the magnetically ordered states. The spectra can be explained with the on-site magnetic interaction 
, the coupling of 
with quadrupole 
, and the uniaxial crystalline electric field. The 
-electron states reproduce the temperature dependences of the in-plane moment 
which is the primary order parameter, and a weakly induced 
as the secondary order parameter. The magnetic-quadrupole coupling emerges and play essential role under the geometrical frustration, where the Heisenberg interactions are cancelled out.
Nishihara, Kenji
Enerugi, Shigen, 45(6), p.359 - 363, 2024/11
no abstracts in English
Bachmann, A. M.*; Richards, S.*; Feng, B.*; Nishihara, Kenji; Abe, Takumi
Proceedings of International Conference on Nuclear Fuel Cycle (GLOBAL2024) (Internet), 4 Pages, 2024/10
This work demonstrates the value of code verification as an initial step in utilizing fuel cycle simulation. Cyclus and NMB are open-source fuel cycle simulators that provide computational modeling of nuclear fuel cycle alternatives and were chosen by Argonne National Laboratory and Japan Atomic Energy Agency (JAEA), respectively, for a multi-year collaboration on fuel cycle benchmarks. Both are relatively new and can be improved after conducting a rigorous code-to-code comparison. Initial verification of these simulators was performed using a set of hypothetical scenarios for once-through and multi-recycle fuel cycles. The results of this work identify how differences in scenario definitions and the modeling methodologies of the two simulators lead to differences in results in material inventories, mass flows, and other important metrics for fuel cycle assessments.
Sogabe, Joji; Ishida, Shinya; Tagami, Hirotaka; Okano, Yasushi; Kamiyama, Kenji; Onoda, Yuichi; Matsuba, Kenichi; Yamano, Hidemasa; Kubo, Shigenobu; Kubota, Ryuzaburo*; et al.
Proceedings of International Conference on Nuclear Fuel Cycle (GLOBAL2024) (Internet), 4 Pages, 2024/10
In the frame of France-Japan collaboration, the calculational methodologies were defined and assessed, and the phenomenology and the severe accident consequences were investigated in a pool-type sodium-cooled fast reactor.
Nishihara, Kenji; Sugawara, Takanori; Fukushima, Masahiro; Iwamoto, Hiroki; Katano, Ryota; Abe, Takumi
Proceedings of International Conference on Nuclear Fuel Cycle (GLOBAL2024) (Internet), 4 Pages, 2024/10
A pilot plant for the accelerator-driven system is proposed as a scaled-down version of a lead-bismuth cooled ADS with 800 MW thermal output for transmutation of minor actinides. In this presentation, the design policy of the pilot plant is presented.
Abe, Takumi; Nishihara, Kenji
Proceedings of International Conference on Nuclear Fuel Cycle (GLOBAL2024) (Internet), 4 Pages, 2024/10
The robustness of whole of a nuclear fuel cycle (NFC) can be evaluated by a simulation of future operation factors (OFs) of the NFC facilities and mass flow analysis coupled with the simulated OF. In this study, the impact of a reprocessing plant OF on a fast reactor OF was quantified.
Takeshita, Kenji*; Okamura, Tomohiro*; Nakase, Masahiko*; Nishihara, Kenji; Abe, Takumi
Proceedings of International Conference on Nuclear Fuel Cycle (GLOBAL2024) (Internet), 2 Pages, 2024/10
Using the dynamic nuclear fuel cycle simulator NMB4.0, the mass balance analysis of the nuclear fuel cycle assuming the introduction of the metal fuel fast reactor in the second half of this century was evaluated. The impact of the introduction of the fast reactor cycle on the back-end including final disposal was discussed.
Abe, Takumi; Nishihara, Kenji
Journal of Nuclear Science and Technology, 61(8), p.1048 - 1060, 2024/08
Times Cited Count：0 Percentile：0.00(Nuclear Science & Technology)Methods of direct disposal of mixed oxide spent fuel (MOXSF) consumed in light water reactors were investigated via heat transfer calculation. The temperature of the buffer material surrounding the waste is the most stringent limitation on the direct disposal of MOXSF. Therefore, the effects on the maximum temperature of the buffer material were examined by changing the occupied area, cooling term of MOXSF, and other parameters considering the direct disposal of uranium spent fuel. The results showed that it is necessary to change the cooling term and disposal depth in addition to the change of the occupied area. Accordingly, some disposal concepts that satisfy the limitation of the maximum buffer material temperature were derived, and estimates revealed that the occupied area per unit waste of the MOXSF is three to five times that of uranium spent fuel.
Yamagishi, Isao; Hato, Shinji*; Nishihara, Kenji; Tsubata, Yasuhiro; Sagawa, Yusuke*
JAEA-Data/Code 2024-002, 63 Pages, 2024/07
JAEA-Data-Code-2024-002.pdf:2.91MB
JAEA-Data-Code-2024-002-appendix(CD-ROM).zip:9.42MB
Adsorption columns filled with zeolite are used to treat contaminated water containing radioactive cesium generated by the Fukushima Daiichi Nuclear Power Station accident. As the contaminated water treatment progresses, the radioactive cesium in the adsorption column becomes highly concentrated, and the adsorption column becomes a high radiation source. To evaluate the radiation effects such as decay heat and radiolytic hydrogen production in the adsorption column, the concentration of radioactive cesium in the adsorption column is necessary, but since it is difficult to evaluate the concentration by measurement, it is estimated by simulation. In this research, a zeolite column adsorption dynamics simulation (Zeolite Adsorption Column: ZAC) code was developed to calculate the concentration of radioactive materials such as radioactive cesium in a zeolite filled adsorption column when they are injected into the column. The code was validated through comparison of calculation results with existing codes and experimental results of small column tests. This report presents the details of the model, the handling of the code, and the validity of the results for the developed code.
Tanaka, Kazuya; Yamaji, Keiko*; Masuya, Hayato*; Tomita, Jumpei; Ozawa, Mayumi*; Yamasaki, Shinya*; Tokunaga, Kohei; Fukuyama, Kenjin*; Ohara, Yoshiyuki*; Maamoun, I.*; et al.
Chemosphere, 355, p.141837_1 - 141837_11, 2024/05
In this study, biogenic Mn(IV) oxide was applied to remove Ra from mine water collected from a U mill tailings pond in the Ningyo-toge center. Just 7.6 mg of biogenic Mn(IV) oxide removed more than 98% of the 
Ra from 3 L of mine water, corresponding to a distribution coefficient of 10
mL/g for Ra at pH 7. The obtained value was convincingly high for practical application of biogenic Mn(IV) oxide in water treatment.
Miyazaki, Kanako*; Takehara, Masato*; Minomo, Kenta*; Horie, Kenji*; Takehara, Mami*; Yamasaki, Shinya*; Saito, Takumi*; Onuki, Toshihiko*; Takano, Masahide; Shiotsu, Hiroyuki; et al.
Journal of Hazardous Materials, 470(15), p.134104_1 - 134104_11, 2024/05
Times Cited Count：1 Percentile：31.14(Engineering, Environmental)
-wave resonance of 
+
Okudaira, Takuya*; Nakabe, Rintaro*; Auton, C. J.*; Endo, Shunsuke; Fujioka, Hiroyuki*; Gudkov, V.*; Ide, Ikuo*; Ino, Takashi*; Ishikado, Motoyuki*; Kambara, Wataru*; et al.
Physical Review C, 109(4), p.044606_1 - 044606_9, 2024/04
Times Cited Count：2 Percentile：74.11(Physics, Nuclear)
-odd/
-odd interactions on the 0.75 eV -wave resonance in 
+
forward transmission determined using a pulsed neutron beamNakabe, Rintaro*; Auton, C. J.*; Endo, Shunsuke; Fujioka, Hiroyuki*; Gudkov, V.*; Hirota, Katsuya*; Ide, Ikuo*; Ino, Takashi*; Ishikado, Motoyuki*; Kambara, Wataru*; et al.
Physical Review C, 109(4), p.L041602_1 - L041602_4, 2024/04
Times Cited Count：1 Percentile：18.90(Physics, Nuclear)
CoSiYamauchi, Hiroki; Sari, D. P.*; Yasui, Yukio*; Sakakura, Terutoshi*; Kimura, Hiroyuki*; Nakao, Akiko*; Ohara, Takashi; Honda, Takashi*; Kodama, Katsuaki; Igawa, Naoki; et al.
Physical Review Research (Internet), 6(1), p.013144_1 - 013144_9, 2024/02
Zhang, Y.*; Marusawa, Kenji*; Kudo, Kohei*; Morooka, Satoshi; Harjo, S.; Miyamoto, Goro*; Furuhara, Tadashi*
ISIJ International, 64(2), p.245 - 256, 2024/01
Times Cited Count：2 Percentile：57.76(Metallurgy & Metallurgical Engineering)Katsumura, Kosuke*; Takagi, Junichi*; Hosomi, Kenji*; Miyahara, Naoya*; Koma, Yoshikazu; Imoto, Jumpei; Karasawa, Hidetoshi; Miwa, Shuhei; Shiotsu, Hiroyuki; Hidaka, Akihide*; et al.
Nihon Genshiryoku Gakkai-Shi ATOMO
, 65(11), p.674 - 679, 2023/11
no abstracts in English
Nishihara, Kenji
Genshiryoku Nenkan 2024, p.78 - 83, 2023/10
The aim and overall picture of partitioning and transmutation technology will be described, and the recent research and development status of JAEA for each of partitioning and transmutation will be outlined.
