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Center for Computational Science & e-Systems
JAEA-Evaluation 2026-003, 41 Pages, 2026/06
JAEA-Evaluation-2026-003.pdf:1.08MB
Research on advanced computational science for nuclear applications, based on "the plan to achieve the medium- and long-term goal of the Japan Atomic Energy Agency", has been performed by Center for Computational Science & e-Systems (CCSE), Japan Atomic Energy Agency. CCSE established a committee consisting of external experts and authorities which evaluates and advises toward the future research and development. This report summarizes the results of the R&D performed by CCSE in FY2024 (April 1st, 2024 - March 31st, 2025) and their evaluation by the committee.
Nakajima, Ryota; Sakai, Tatsuya; Tani, Riku; Handa, Yuichi; Sunaoshi, Mizuho*; Inoue, Hidetaka*; Yamada, Satoshi; Shimizu, Osamu
JAEA-Technology 2025-012, 39 Pages, 2026/01
JAEA-Technology-2025-012.pdf:2.31MB
JAERI's Reprocessing Test Facility (JRTF) has transition to decommissioning since 1996 and inside the facility dismantled equipment and instrument. In the dismantling and removal work of glove boxes and other equipment, starting in October 2022, we prepared a "Manual for Separation of Dismantled Materials of JRTF" and carried out sorting and separation of the generated dismantled waste with the aim of producing waste package that meets the technical standards required for disposal to a landfill facility. This report describes the results and findings of sorting and separating the dismantled waste generated during the dismantling and removal work of glove boxes and other equipment in accordance with the "Manual for Separation of Dismantled Materials of JRTF".
Myagmarjav, O.; Noguchi, Hiroki; Tanaka, Nobuyuki; Kamiji, Yu; Sugimoto, Chihiro; Ishii, Katsunori; Nomura, Mikihiro*; Takegami, Hiroaki
International Journal of Hydrogen Energy, 198, p.152495_1 - 152495_9, 2026/01
Times Cited Count：1 Percentile：19.59(Chemistry, Physical)Wada, Kazuma*; Kazama, Hiroyuki*; Abe, Chikage*; Onishi, Takashi; Yamamoto, Masahiko; Taguchi, Shigeo; Kuno, Takehiko; Maeda, Koji; Idemitsu, Kazuya*; Suzuki, Tatsuya*
Journal of Radioanalytical and Nuclear Chemistry, 334(11), p.8961 - 8968, 2025/11
Times Cited Count：0 Percentile：0.00(Chemistry, Analytical)The feasibility of using commercially available polyvinylpolypyrrolidone (PVPP) as a pretreatment for mass spectrometry to separate actinides was investigated. Uranium, thorium, and plutonium were used as actinides in the study. Adsorption data for An(IV) and An(VI) were obtained by adsorption experiments in nitric acid. In addition, An(III)/An(IV)/An(VI) mutual separation was successfully performed by a column separation method using PVPP. Furthermore, the elution efficiency of U(VI) was improved by the introduction of carbonate ions. This method may be applicable as a mutual separation for actinide mass spectrometry.
Sasaki, Yuji; Kaneko, Masashi; Kumagai, Yuta; Ban, Yasutoshi
Progress in Nuclear Science and Technology (Internet), 8, p.202 - 204, 2025/09
Two extractants and a masking agent of TODGA (TetraOctyl-DiGlycolAmide), ADAAM (AlkylDiAmideAMine), and DTBA (DiethyleneTriamine-triacetic-BisAmide) were developed in JAEA. TODGA can extract both trivalent actinides (An) and lanthanides (Ln), DTBA may separate An from Ln, and ADAAM has high separation factor (SF: 6) for Am/Cm. The suitable conditions for the extraction, separation and isolations of An from Ln are investigated using these reagents. In this work, we show the basic information on extraction behavior of An and Ln using TODGA, DTBA and ADAAM and propose the suitable aqueous and the organic conditions for An+Ln extraction, An/Ln separation and Am/Cm separation.
Toigawa, Tomohiro; Tsubata, Yasuhiro; Kumagai, Yuta; Ban, Yasutoshi
Progress in Nuclear Science and Technology (Internet), 8, p.286 - 290, 2025/09
We propose a simple process simulation methodology that uses readily available information about radiation impact. A process simulation was conducted for a minor actinides (MA) separation process while considering the degradation of extraction ability by radiolysis. The simulation provided a processing limit of MA and enabled the evaluation of radiation stability.
Sasaki, Yuji; Kaneko, Masashi; Kumagai, Yuta; Ban, Yasutoshi
Solvent Extraction and Ion Exchange, 43(5-6), p.768 - 784, 2025/06
Times Cited Count：0 Percentile：0.00(Chemistry, Multidisciplinary)We developed a method called the alkyl-diamide amine (ADAAM(EH))-diethylenetriamine-triacetic acid-bis(diethylacetamide) (DTBA) technique for separating actinide (An) and lanthanide (Ln) elements from high-level liquid waste. ADAAM(EH) exhibits a high separation factor (SF) not only for Am/Cm but also for light/heavy Ln under acidic conditions (1.5 M HNO
). Consequently, Am can be separated from Cm as well as from middle Ln (Sm, Eu, and Gd) using ADAAM(EH) as an extractant. DTBA enables the stripping of Am and potentially separates it from Ln in the organic phase at low pH (
2). The lowest SF among the light Ln, observed for Nd/Am, exceeded 10, indicating that Am can be separated from light Ln by stripping using DTBA from the ADAAM(EH) extraction solvent. The density functional theory calculations for understanding the coordination bond properties of metal-DTBA complexes are performed, which supported higher affinity of DTBA toward Am than Nd.
Aoki, Katsutoshi*; Machida, Akihiko*; Saito, Hiroyuki*; Hattori, Takanori
Koatsuryoku No Kagaku To Gijutsu, 35(1), p.4 - 11, 2025/03
Iron reacts with hydrogen to form solid solutions with body-centered cubic, face-centered cubic, hexagonal close packed, and double hexagonal close packed structures at high temperatures and high pressures. Neutron diffraction is the most powerful tool for determining the occupation sites and occupancies of hydrogen atoms dissolved in a metal lattice. Structural parameters, including hydrogen occupation sites and occupancies, are refined via Rietveld analysis for neutron diffraction data. We present our expertise in Rietveld refinement of iron hydrides accumulated over 10 years.
Myagmarjav, O.; Tanaka, Nobuyuki; Noguchi, Hiroki; Kamiji, Yu; Ono, Masato; Nomura, Mikihiro*; Takegami, Hiroaki
Progress in Nuclear Science and Technology (Internet), 7, p.235 - 242, 2025/03
Sun, Haomin; Hibiki, Takashi*
International Journal of Heat and Mass Transfer, 237, p.126445_1 - 126445_14, 2025/02
Times Cited Count：4 Percentile：40.64(Thermodynamics)Teshigawara, Makoto; Lee, Y.*; Tatsumoto, Hideki*; Hartl, M.*; Aso, Tomokazu; Iverson, E. B.*; Ariyoshi, Gen; Ikeda, Yujiro*; Hasegawa, Takumi*
Nuclear Instruments and Methods in Physics Research B, 557, p.165534_1 - 165534_10, 2024/12
Times Cited Count：1 Percentile：22.55(Instruments & Instrumentation)At Japanese Spallation Neutron Source in J-PARC, the para-hydrogen fraction was measured by using Raman spectroscopy in-situ for an integrated beam power of 9.4 MW
h at 1 MW operation, to evaluate the functionality of the ferric oxyhydroxide catalyst. This result showed that full functionality of the catalyst was retained up to the 1 MW operation. We attempted to study the effect of neutron scattering driven para to ortho-hydrogen back-conversion rate in the absence of the catalyst effect with a bypass line without catalyst. The measured increase of ortho-hydrogen fraction was 0.44% for an integrated beam power of 2.4 MWh at 500 kW operation, however, which was considered to be due to not only to neutron collisions in cold moderators but also to the high ortho-hydrogen fraction of initially static liquid hydrogen in the bypass line and passive exudation of quasi-static hydrogen in the catalyst vessel to the main loop.
Mikhail, M. A. G.*; Kin, Tadahiro*; Eto, Taisei*; Tsukada, Kazuaki
Scientific Reports (Internet), 14, p.27132_1 - 27132_10, 2024/11
Times Cited Count：0 Percentile：0.00(Multidisciplinary Sciences)We have studied a straightforward and robust single-step cation exchange separation method to isolate medical copper radioisotopes 
Cu and 
Cu produced in the 
Zn(n, x) reaction with an accelerator neutrons technique. This study revealed the key role of a phosphate buffer pre-treatment of the cation exchange column in the separation process. It was found that incorporating the phosphate buffer into the column pre-treatment markedly enhances the retention of copper isotopes within the column throughout the separation procedure. This approach yields a high-purity radioactive copper sample with a high extraction efficiency of 94.4% of the initially produced copper, all within a relatively short experimental time frame of approximately 5 h for 100 g of starting material.
Center for Computational Science & e-Systems
JAEA-Evaluation 2024-001, 40 Pages, 2024/10
JAEA-Evaluation-2024-001.pdf:1.46MB
Research on advanced computational science for nuclear applications, based on "the plan to achieve the medium- and long-term goal of the Japan Atomic Energy Agency", has been performed by Center for Computational Science & e-Systems (CCSE), Japan Atomic Energy Agency. CCSE established a committee consisting of external experts and authorities which evaluates and advises toward the future research and development. This report summarizes the results of the R&D performed by CCSE in FY2023 (April 1st, 2023 - March 31st, 2024) and their evaluation by the committee.
Vauchy, R.; Hirooka, Shun; Horii, Yuta; Ogasawara, Masahiro*; Sunaoshi, Takeo*; Yamada, Tadahisa*; Tamura, Tetsuya*; Murakami, Tatsutoshi
Journal of Nuclear Materials, 599, p.155233_1 - 155233_11, 2024/10
Times Cited Count：2 Percentile：38.41(Materials Science, Multidisciplinary)The fluorite exsolution/recombination in U
Pu
O
(y = 0.30 and 0.45) and PuO was investigated using differential scanning calorimetry. The results are in relatively good agreement with the literature data, except for plutonia. Our values indicate that the critical temperature of the miscibility gap in Pu-O is 30
50 K lower than previously reported. Finally, the systematic experimental procedure allowed us refining the locus of the solvus existing in hypostoichiometric U
0Pu
O, U
Pu
O, and PuO dioxides.
Sugiura, Yuki; Ishidera, Takamitsu; Aoyagi, Noboru; Mei, H.; Saito, Takumi*; Tachi, Yukio
Applied Clay Science, 258, p.107476_1 - 107476_10, 2024/09
Times Cited Count：4 Percentile：53.08(Chemistry, Physical)Sasaki, Yuji; Kaneko, Masashi; Ban, Yasutoshi; Suzuki, Hideya*
Journal of Nuclear Science and Technology, 61(7), p.883 - 893, 2024/07
Times Cited Count：5 Percentile：58.89(Nuclear Science & Technology)The mutual separation of Am and Cm is conducted using an alkyl-diamide amine (ADAAM) extractant. ADAAM exhibits extremely high separation factor with respect to Am and Cm separation (5.9) in a nitric acid-
-dodecane system. The batch-wise multistage extractions are performed using a system containing 0.2 M ADAAM and 1.5 M nitric acid. In this multistage extraction, an organic solvent give 96.5% and 1.06% yields of Am and Cm. After the mutual separation of Am and Cm, an additional extraction step is included to reduce the volumes of these aqueous and organic phases. Taking these steps, Am and Cm can be recovered in just two or three stages in the aqueous phases.
C to 1000CImagawa, Yuya; Hashidate, Ryuta; Miyazawa, Takeshi; Onizawa, Takashi; Otsuka, Satoshi; Yano, Yasuhide; Tanno, Takashi; Kaito, Takeji; Onuma, Masato*; Mitsuhara, Masatoshi*; et al.
Journal of Nuclear Science and Technology, 61(6), p.762 - 777, 2024/06
Times Cited Count：8 Percentile：77.35(Nuclear Science & Technology)The Japan Atomic Energy Agency has been developing 9Cr-oxide dispersion strengthened (ODS) steel as a fuel cladding material for sodium-cooled fast reactors (SFRs). Previous studies have formulated the creep rupture equation for 650C to 850C. However, little data have been obtained above 850C, and no equation has been formulated. This study conducted creep tests to evaluate creep strength at 700C to 1000C. Two creep test methods, the internal pressure and ring creep tests under development, were used, and the validation of the ring creep test method was conducted. The results showed that 9Cr-ODS steel undergoes almost no strength change due to the matrix's phase transformation, and a single equation can express a creep rupture strength from 700C to 1000C. In validating the ring creep test method, analysis clarified the effect of stress concentration on the specimen. Plastic deformation occurs at high initial stress and may lead to early rupture. The results will be essential for future creep testing and evaluation of neutron-irradiated 9Cr-ODS steel.
Sun, Haomin; Kunugi, Tomoaki*; Yokomine, Takehiko*; Shen, X.*; Hibiki, Takashi*
Experimental Thermal and Fluid Science, 154, p.111171_1 - 111171_24, 2024/05
Times Cited Count：5 Percentile：60.24(Thermodynamics)Miyazawa, Takeshi; Tanno, Takashi; Imagawa, Yuya; Hashidate, Ryuta; Yano, Yasuhide; Kaito, Takeji; Otsuka, Satoshi; Mitsuhara, Masatoshi*; Toyama, Takeshi*; Onuma, Masato*; et al.
Journal of Nuclear Materials, 593, p.155008_1 - 155008_16, 2024/05
Times Cited Count：6 Percentile：79.07(Materials Science, Multidisciplinary)Mei, H.; Aoyagi, Noboru; Saito, Takumi*; Tanaka, Kazuya; Sugiura, Yuki; Tachi, Yukio
Applied Geochemistry, 162, p.105926_1 - 105926_8, 2024/02
Times Cited Count：8 Percentile：70.20(Geochemistry & Geophysics)