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Kikuchi, Shin; Kondo, Toshiki; Doi, Daisuke; Seino, Hiroshi; Ogawa, Kengo*; Nakagawa, Takeshi*
Proceedings of 14th International Topical Meeting on Nuclear Reactor Thermal-Hydraulics, Operation, and Safety (NTHOS-14) (Internet), 12 Pages, 2024/08
Konno, Chikara; Kochiyama, Mami; Hayashi, Hirokazu
Mechanical Engineering Journal (Internet), 11(2), p.23-00386_1 - 23-00386_11, 2024/04
Activation cross-section libraries for the ORIGEN and ORIGEN-S codes have been generated from JENDL-5 and JENDL/AD-2017. The ORIGEN activation cross-section libraries of the 200 and 48 group structures were generated with the AMPX-6 code, while the ORIGEN-S activation cross-section libraries with a MAXS format of the 199 group structure were done with the PREPO2018 code. Activation calculations for JPDR were carried out in order to validate the produced ORIGEN and ORIGEN-S activation cross-section libraries. The following comparisons were performed: the ORIGEN calculation results with the produced activation cross-section libraries and bundled ones, the 200 group and 48 group ORIGEN calculations, the ORIGEN and ORIGEN-S calculations with the JENDL-5 activation cross-section libraries, etc. Most of the differences of the calculation results were less than 20%, which demonstrated that the libraries were produced adequately.
Suzuki, Tomoya*; Otsubo, Ukyo*; Ogata, Takeshi*; Shiwaku, Hideaki; Kobayashi, Toru; Yaita, Tsuyoshi; Matsuoka, Mitsuaki*; Murayama, Norihiro*; Narita, Hirokazu*
Separation and Purification Technology, 308, p.122943_1 - 122943_7, 2023/03
Times Cited Count:3 Percentile:19.99(Engineering, Chemical)HNO leaching is used in recycling Pd metal from spent products that primarily contain Ag, and most Pd residues are separated from solutions containing Ag(I). However, a small amount of Pd(II) often remains in these Ag(I) solutions. Therefore, the separation of Pd(II) and Ag(I) in HNO solutions is essential to promote efficient Pd recycling. In this study, the separation of Pd(II) and Ag(I) in HNO solutions was investigated using four N-donor-type adsorbents functionalized with amine (R-Amine), iminodiacetic acid (R-IDA), pyridine (R-Py), or bis-picolylamine (R-BPA). R-Amine, R-IDA, and R-Py selectively adsorbed Pd(II) over Ag(I), Cu(II), Ni(II), and Fe(III) from HNO solutions (0.3-7 M), but R-Amine exhibited a lower Pd adsorption efficiency. In contrast, 90% of Pd(II), Ag(I), and Cu(II) were adsorbed by R-BPA over the entire range of HNO concentrations. Structural analyses of the adsorbed metal ions using Fourier transform infrared spectroscopy and extended X-ray absorption fine structure spectroscopy revealed the separation mechanisms of the N-donor-type adsorbents. Pd(II) adsorption on R-IDA, R-Py, and R-BPA occurred via Pd(II) coordination of the functional groups (iminodiacetic acid, pyridine, and bis-picolylamine, respectively), whereas that on R-Amine occurred via anion exchange of NO with [Pd(NO)]. The coordinative adsorption mechanisms resulted in the higher Pd(II) adsorption behaviors of R-IDA, R-Py, and R-BPA. HCl (5.0 M) and thiourea (0.1 M) eluents desorbed 83% of Pd(II) from R-IDA and 95% from R-Py, respectively. R-Py was the most effective Pd(II) adsorbent based on adsorption selectivity and desorption efficiency.
Tsuchida, Daiki; Mitsukai, Akina; Aono, Ryuji; Haraga, Tomoko; Ishimori, Kenichiro; Kameo, Yutaka
JAEA-Data/Code 2022-004, 87 Pages, 2022/07
Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes until by the beginning of disposal. In order to contribute to this work, we collected and analyzed samples generated from JPDR, JRR-3 and JRR-4. In this report, radioactivity concentrations of 20 radionuclides (H, C, Cl, Co, Ni, Sr, Nb, Tc, Ag, I, Cs, Eu, Eu, U, U, Pu, Pu, Am, Cm) were determined based on radiochemical analysis and summarized as basic data for the study of evaluation method of radioactive concentration.
Tang, J.*; Seo, O.*; Rivera Rocabado, D. S.*; Koitaya, Takanori*; Yamamoto, Susumu*; Namba, Yusuke*; Song, C.*; Kim, J.*; Yoshigoe, Akitaka; Koyama, Michihisa*; et al.
Applied Surface Science, 587, p.152797_1 - 152797_8, 2022/06
Times Cited Count:9 Percentile:66.53(Chemistry, Physical)The hydrogen absorption and diffusion mechanisms on cube-shaped Pd nanoparticles (NPs) which are important hydrogen-storage materials were studied using X-ray photoelectron spectroscopy and DFT calculations. In the surface region, hydrogen absorption showed almost similar behavior regardless of the NPs size. It was found that the octahedral sites are more favorable than the tetrahedral sites for hydrogen occupation. We also clarified that the hydrogen atoms absorbing on the smaller-sized Pd NPs diffuse to the subsurface more actively because of the weakened Pd-H bond by the surface disordering, which plays an important role in hydrogen adsorption at a low H pressure.
Tobita, Minoru*; Haraga, Tomoko; Endo, Tsubasa*; Omori, Hiroyuki*; Mitsukai, Akina; Aono, Ryuji; Ueno, Takashi; Ishimori, Kenichiro; Kameo, Yutaka
JAEA-Data/Code 2021-013, 30 Pages, 2021/12
Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes until the beginning of disposal. In order to contribute to this work, we collected and analyzed concrete samples generated from JPDR facility. In this report, we summarized the radioactivity concentrations of 21 radionuclides (H, C, Cl, Ca, Co, Ni, Sr, Nb, Ag, Cs, Eu, Eu, Ho, U, U, Pu, Pu, Pu, Am, Am, Cm) which were obtained from radiochemical analysis of the samples in fiscal year 2018-2019.
Nakashima, Koichi*; Hironaka, Kota*; Ouchi, Kazuma*; Ajioka, Mao*; Kobayashi, Yoshio*; Yoneda, Yasuhiro; Yin, S.*; Kakihana, Masato*; Sekino, Toru*
ACS Omega (Internet), 6(48), p.32517 - 32527, 2021/12
Times Cited Count:6 Percentile:34.61(Chemistry, Multidisciplinary)The BaTiO nanoparticles synthesized by the hydrothermal method is examined by synchrotron X-ray and TEM observation. It was found that the particle size of synthesized BaTiO depends on the particle size of the raw material of TiO. Succeeded in synthesizing 100 nm size BaTiO nanocrystals showing uniform particle size distribution using TiO nanoparticles with optimized particle size. The obtained BaTiO nanocrystal is a tetragonal system of ferroelectric phase. A three-dimensional structure of BaTiO nanoparticles could be obtained by the electron beam tomography.
Sakai, Toshihiro; Ishii, Eiichi
JAEA-Data/Code 2021-009, 13 Pages, 2021/08
Japan Atomic Energy Agency is performing the Horonobe Underground Research Laboratory Project, which includes a scientific study of the deep geological environment as a basis of research and development for the geological disposal of high level radioactive wastes, in order to establish comprehensive techniques for the investigation, analysis and assessment of the deep geological environment in the sedimentary rock. The numerical data of 3D geological model in regional-scale was compiled in 2019 as JAEA-Data/Code 2019-007, and then this report updates a part of the numerical data of 3D geological model around the underground facilities.
Kochiyama, Mami; Okada, Shota; Sakai, Akihiro
JAEA-Technology 2021-010, 61 Pages, 2021/07
It is necessary to evaluate the radioactivity inventory in wastes in order to dispose of radioactive wastes generated from dismantling nuclear reactor in the shallow ground. In this report, we examined radioactivity evaluation method for near surface disposal about biological shield concrete near the core generated from the dismantling of JPDR. We calculated radioactive concentration of the target biological concrete using the DORT code and the ORIGEN-S code, and we estimated radioactivity concentration Di (Bq/t). For DORT calculation, the cross-section library created from the MATXSLIB-J40 file from JENDL-4.0 was used, and for ORIGEN-S, the attached library of SCALE6.0 was used. As a result of comparing the calculation results of the radioactivity concentration with the past measured values in the radial direction and the vertical direction, we found that the trends were generally the same. We calculated radioactive concentration of the target biological concrete Di (Bq/t), and we compared with the estimated Ci (Bq/t) equivalent to the dose criteria of trench disposal calculated for 140 nuclides. As a result we inferred that the except for about 2% of target waste could be disposed of in the trench disposal facility. We also preselected important nuclides for trench disposal based on the ratios (Di/Ci) for each nuclide, H-3, C-14, Cl-36, Ca-41, Co-60, Sr-90, Eu-152 and Cs-137 were selected as important nuclides.
Tsuchida, Daiki; Haraga, Tomoko; Tobita, Minoru*; Omori, Hiroyuki*; Omori, Takeshi*; Murakami, Hideaki*; Mitsukai, Akina; Aono, Ryuji; Ishimori, Kenichiro; Kameo, Yutaka
JAEA-Data/Code 2020-022, 34 Pages, 2021/03
Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes until the beginning of disposal. In order to contribute to this work, we collected and analyzed concrete samples generated from JRR-3 and JPDR. In this report, we summarized the radioactivity concentrations of 22 radionuclides(H, C, Cl, Ca, Co, Ni, Sr, Nb, Ag, Ba, Cs, Eu, Eu, Ho, U, U, Pu, Pu, Am, Am, Cm) which were obtained from radiochemical analysis of the samples.
Kitamura, Akira
JAEA-Data/Code 2020-020, 164 Pages, 2021/03
Part of JAEA's Thermodynamic Database (JAEA-TDB) for solubility and speciation of radionuclides (JAEA-TDB-RN) for performance assessment of geological disposal of high-level radioactive and TRU wastes has been updated with subsuming the database for geochemical calculations (JAEA-TDB-GC). This report has focused to update JAEA-TDB-RN after selecting change in standard Gibbs free energy of formation (), change in standard enthalpy change of formation (), standard molar entropy () and, heat capacity (), change in standard Gibbs free energy of reaction (), change in standard enthalpy change of reaction () and standard entropy change of reaction () as well as logarithm of equilibrium constant (log) at standard state. The extent of selection of these thermodynamic data enables to evaluate solubility and speciation of radionuclides at temperatures other than 298.15 K. Furthermore, the latest thermodynamic data for iron which have been critically reviewed, selected and compiled by the Nuclear Energy Agency within Organisation for Economic Co-operation and Development (OECD/NEA) have been accepted. Most of previously selected log have been refined to confirm internal consistency with JAEA-TDB-GC. Text files of the updated JAEA-TDB have been provided for geochemical calculation programs of PHREEQC and Geochemist's Workbench.
Tsukada, Takashi; Soma, Yasutaka
Hozengaku, 19(4), p.37 - 44, 2021/01
Corrosion Cracking phenomena in JPDR (Japan Power Demonstration Reactor) the first Japanese Light Water Reactor is reviewed. This review describes two major cracking failure. The first was found during inspection in 1966 as the cracking failure on weld-overlay cladding at the inner wall of the top head. A series of analysis showed that some of the cracks reached the base metal across the weld boundaries and further penetrated into the vessel wall. Significant depletion of ferrite content was detected in manually welded part considered to assisted the cracking. These inspection result in improvement of the welding procedure and no similar failures have been reported in Japanese reactor. This mode of failure gave rise to a new research field studying the corrosion fatigue behavior of low alloy steel because of importance to assess pressure boundary of the reactor. The experiment of JPDR also contributed to the establishment of international cooperation for studying EAC (environmentally assisted cracking). The second failure was found in 1972 near the welded part between stainless piping and safe end. The extensive research concluded that this failure was caused by Stress Corrosion Cracking.
Jee, H.*; Im, S.*; Kanematsu, Manabu*; Suzuki, Hiroshi; Morooka, Satoshi; Koyama, Taku*; Machida, Akihiko*; Bae, S.*
Journal of the American Ceramic Society, 103(12), p.7188 - 7201, 2020/12
Times Cited Count:18 Percentile:66.72(Materials Science, Ceramics)Aono, Ryuji; Mitsukai, Akina; Haraga, Tomoko; Ishimori, Kenichiro; Kameo, Yutaka
JAEA-Data/Code 2020-006, 70 Pages, 2020/08
Radioactive wastes which generated from research and testing reactors in Japan Atomic Energy Agency are planning to be buried at the near surface disposal field. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes by the time it starts disposal. In order to contribute to this work, we collected and analyzed the samples generated from JPDR and JRR-4. In this report, we summarized the radioactivity concentrations of 19 radionuclides (H, C, Cl, Co, Ni, Sr, Nb, Tc, Ag, I, Cs, Eu, Eu, U, U, Pu, Pu, Am, Cm) which were obtained from radiochemical analysis of those samples.
Metoki, Naoto
Kotai Butsuri, 55(7), p.285 - 296, 2020/07
Electron states are the main theme of "solid-state physics", which is essential for microscopic understanding of multipoles and superconductivity, etc. Rare earths (4) and actinides (5) provide variety of interesting states realized with competing interactions between the increasing number of electrons. Since crystal field splitting of many-body electron system is smaller than the bandwidth, (1) high resolution experiments are needed, (2) essentially no clear spectrum with well defined peaks is expected in itinerant Ce and U compounds, and (3) Np and Pu is strictly regulated. Therefore, systematic research on magnetic excitations by neutron scattering experiments of localized compounds and rare earth iso-structural reference is useful. We describe the electron states of heavy electron compounds NpPdAl and actinide and rare earth based iso-structural family.
Furutani, Misa; Kometani, Tatsunari; Nakagawa, Masahiro; Ueno, Yumi; Sato, Junya; Iwai, Yasunori*
Hoken Butsuri (Internet), 55(2), p.97 - 101, 2020/06
Herein, an oxidation catalyst was introduced after heating it to 600C to oxidize tritium gas (HT) existing in exhaust into tritiated water vapor (HTO). This study aims to establish a safer H monitoring system by lowering the heating temperature required for the catalyst. In these experiments, which were conducted in the Nuclear Science Research Institute, Japan Atomic Energy Agency, cupric oxide, hydrophobic palladium/silicon dioxide (Pd/SiO), and platinum/aluminum oxide (Pt/AlO) catalysts were ventilated using standard hydrogen gas. After comparing the oxidation efficiency of each catalyst at different temperatures, we found that the hydrophobic Pd/SiO and Pt/AlO catalysts could oxidize HT into HTO at 25C.
Bae, S.*; Jee, H.*; Suh, H.*; Kanematsu, Manabu*; Shiro, Ayumi*; Machida, Akihiko*; Watanuki, Tetsu*; Shobu, Takahisa; Morooka, Satoshi; Geng, G.*; et al.
Construction and Building Materials, 237, p.117714_1 - 117714_10, 2020/03
Times Cited Count:19 Percentile:67.17(Construction & Building Technology)Matsumiya, Masahiko*; Song, Y.*; Tsuchida, Yusuke*; Sasaki, Yuji
Separation and Purification Technology, 234, p.115841_1 - 115841_8, 2020/03
Times Cited Count:18 Percentile:57.03(Engineering, Chemical)The development of solvent extraction and direct electrodeposition processes is an important task to reduce the volume of secondary wastes. In this study, the extraction of Pd(II) from hydrochloric/chloride media using methylimino-bis--dioctylacetamide (MIDOA) in three diluents (acetophenone; AP, 1,2-dichloroethane; DCE, or 1-octanol; OC) and the electrochemical behavior of the extracted Pd(II) complex in the MIDOA/AP bath was investigated. Pd(II) was found to be reduced to Pd(0) metal via a two-electron transfer between -2.38 V and -3.40 V. The potentiostatic electrodeposition of the extracted Pd(II) complex enabled us to recover the blackish electrodeposits, which were identified as Pd metal.
Metoki, Naoto; Aoki, Dai*; Griveau, J.-C.*; Otsuki, Junya*
Journal of the Physical Society of Japan, 89(2), p.024707_1 - 024707_6, 2020/02
Times Cited Count:3 Percentile:27.02(Physics, Multidisciplinary)The pseudo triplet ground state in the heavy-fermion superconductor NpPdAl was concluded. The magnetic susceptibility can be reproduced by the singlet ground state with the main component of and the first excited doublet dominated by at ,K. The magnetization curve can be explained from the effective local hamiltonian for pseudo spin =1 with () equivalent to the quadrupole operator . The specific heat can be described with the Kondo model normalized to give the entropy R, corresponding to the pseudo triplet state. The derived Kondo temperature ,K comparable to the level splitting ,K indicates the contribution of the excited doublet to the possible multi-channel Kondo effect.
Metoki, Naoto
Journal of the Physical Society of Japan, 89(2), p.025001_1 - 025001_2, 2020/02
Times Cited Count:1 Percentile:10.32(Physics, Multidisciplinary)Good correspondence of the and - coupling scheme can be realized in the -electron states of the heavy-fermion superconductor NpPdAl and the isostructural family. The rare-earth and actinide elements are under a common strong uniaxial point charge potential with tetragonal point symmetry . The systematic development of the -electron states can be understood in the coupling scheme of configuration (the number of electrons ). We can find the corresponding states in - coupling scheme with three -orbitals , and determined from CePdAl with configuration.