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Nishihara, Kenji; Iwamura, Takamichi*; Akie, Hiroshi; Nakano, Yoshihiro; Van Rooijen, W.*; Shimazu, Yoichiro*
Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.388 - 395, 2015/09
The present study focuses on transmutation of Pu and minor actinide in Japanese case without utilizing Pu as resource. Pu can be transmuted by two groups of technology: conventional ones without reprocessing of spent fuel from transmuter and advanced ones with reprocessing. Necessary number of transmuters, inventory reduction of actinide and impact on repository are revealed by nuclear material balance analysis. As a whole advanced technology performs better in transmutation efficiency, although required number of transmuters is larger.
Nishihara, Kenji; Akie, Hiroshi; Shirasu, Noriko; Iwamura, Takamichi*
Journal of Nuclear Science and Technology, 51(2), p.150 - 165, 2014/02
Times Cited Count：4 Percentile：30.92(Nuclear Science & Technology)Utilization of rock-like oxide (ROX) fuel in light water reactors for plutonium (Pu) burning was studied by material balance analysis for a case of Japanese phase-out scenario under investigation after the Fukushima accident. For the analysis, the nuclear material balance analysis (NMB) code was developed with features of accurate burn-up calculation, flexible combination of reactors and fuels and an ability to estimate waste and repository. Three scenario-groups of once-through, Pu burning in mixed oxide (MOX) fuel and in ROX fuel were analyzed. By construction of two full MOX- or ROX- reactors, Pu amount is reduced to about a half and isotopic vector of Pu is deteriorated as nuclear weapon especially in terms of spontaneous fission neutron. Effects by ROX are more significant than MOX in both amount and vector. Repository footprint and potential radio-toxicity is not reduced by MOX and ROX because heat and toxicity of MOX and ROX spent fuel is considerably high.
Ismailov, K.*; Nishihara, Kenji; Saito, Masaki*; Sagara, Hiroshi*
Annals of Nuclear Energy, 56, p.136 - 142, 2013/06
Times Cited Count：6 Percentile：44.02(Nuclear Science & Technology)The transmutation of iodine-129 in accelerator driven system (ADS) is studied. The sodium iodide assembly loadings inside the core of ADS and in the surrounding core region are considered. The introduced concept of ADS with a power of 800 MWt is able to transmute 250 kg/y of minor actinides (MAs) and 46 kg/y of Iodine-129 that supports ten PWRs. The initial loading masses of MAs and I-129 in ADS were equal to 3810 kg and 824 kg, respectively.
Ismailov, K.*; Saito, Masaki*; Sagara, Hiroshi*; Nishihara, Kenji
Progress in Nuclear Energy, 53(7), p.925 - 929, 2011/09
Times Cited Count：10 Percentile：60.88(Nuclear Science & Technology)A feasibility study on natural uranium spallation target in accelerator-driven system (ADS) for minor actinide (MA) transmutation was performed. As a result of comparative study of uranium and lead-bismuth (PbBi) targets in the bare case without blanket surrounding, it was found that uranium target had better neutron generation performance, but limited by the geometrical size due to high neutron absorption in 
U. In ADS for MA transmutation, uranium used as target instead of PbBi also absorbs neutrons passing the target area. More realistic concept of pin type uranium spallation target cooled by liquid PbBi was considered aiming at enhancing spallation target performance in terms of neutron generation efficiency and operation temperature. The uranium pin target design had nothing better effects on neutron balance of such system than a conventional PbBi target in ADS and it was concluded that uranium target was not suitable for the full-scale ADS.
Tomimoto, Hiroshi; Hamamoto, Shimpei; Tochio, Daisuke; Ueta, Shohei; Umeda, Masayuki; Nishihara, Tetsuo
JAEA-Technology 2009-026, 37 Pages, 2009/08
JAEA-Technology-2009-026.pdf:8.9MB
HTTR (High Temperature Engineering Test Reactor) loaded the first driver fuel in July 1998 and reached first criticality state in November 1998. After power increasing examination, HTTR has been conducting safety demonstration test and sequentially acquiring basic technical data of high temperature gas cool reactor. Temperature measurement inside the reactor is planed in the next midterm plan to improve HTTR performance. This report describes the investigation result of fuel temperature measurement method which is applicable to critical irradiation test.
Tomimoto, Hiroshi; Kato, Yasushi; Owada, Hiroyuki; Sato, Nao; Shimazaki, Yosuke; Kozawa, Takayuki; Shinohara, Masanori; Hamamoto, Shimpei; Tochio, Daisuke; Nojiri, Naoki; et al.
JAEA-Technology 2009-025, 29 Pages, 2009/06
JAEA-Technology-2009-025.pdf:21.78MB
The first driver fuel of the HTTR (High Temperature Engineering test Reactor) was loaded in 1998 and the HTTR reached first criticality state in the same year. The HTTR has been operated using the first driver fuel for a decade. In Fuel elements assembling, 4770 of fuel rods which consist of 12 kinds of enrichment uranium are loaded into 150 fuel graphite blocks for HTTR second driver fuel elements. Measures of prevention of fuel rod miss loading, are employed in fuel design. Additionally, precaution of fuel handling on assembling are considered. Reception of fuel rods, assembling of fuel elements and storage of second driver fuels in the fresh fuel storage rack in the HTTR were started since June, 2008. Assembling, storage and pre-service inspection were divided into three parts. The second driver fuel assembling was completed in September, 2008. This report describes concerns of fuel handling on assembling and storage work for the HTTR fuel elements.
Tomimoto, Hiroshi; Umeda, Masayuki; Nishihara, Tetsuo; Iyoku, Tatsuo
UTNL-R-0471, p.11_1 - 11_9, 2009/03
The first driver fuel of the HTTR (High Temperature Engineering test Reactor) was loaded in 1998 and the HTTR reached first criticality state in the same year. The HTTR has been operated using the first driver fuel for a decade. HTTR reactor core consist of twelve kinds of enriched uranium fuel elements. Fuel rods were designed for avoiding fuel rod false loading because fuel rods number is 4770, and it was considered on handling. Reception of fuel rods, assembling of fuel elements and storage of second driver fuels in the fresh fuel storage rack in the HTTR were started since June, 2008. Pre-service inspection was finished. And the second driver fuel assembling was completed in September, 2008. This report describes concerns of fuel handling on assembling and storage work for the HTTR fuel elements.
Wada, Atsushi*; Watanabe, Masayuki; Yamanoi, Yoshinori*; Nankawa, Takuya; Namiki, Kosuke*; Yamasaki, Mikio*; Murata, Masaki*; Nishihara, Hiroshi*
Bulletin of the Chemical Society of Japan, 80(2), p.335 - 345, 2007/02
Times Cited Count：22 Percentile：57.38(Chemistry, Multidisciplinary)Lanthanide complexes with linear and cyclic octadentate oligopyridine-amine ligands were synthesized, and their molecular structures were determined by single-crystal X-ray crystallography. All of the complexes had a distorted capped square antiprism (CSAP) geometry, and the coordination environments of lanthanide complexes were more distortedfor the complexes with the linear ligand than those with the cyclic ligand. The Eu
complexes with the linear ligand showed more intense emissions, which were attributed to the 
D
F
transition, than the complex withthe cyclic ligand in acetonitrile, which can be attributed to the distortion in the coordination environments. These results indicate that the coordination environments of lanthanide complexes, and thus the luminescence properties, can be controlled by tuning the geometrical structures of polydentate ligands.
Sasa, Toshinobu; Umeno, Makoto*; Mizubayashi, Hiroshi*; Mori, Keijiro*; Futakawa, Masatoshi; Saito, Shigeru; Kai, Tetsuya; Nakai, Kimikazu*; Zako, Akira*; Kasahara, Yoshiyuki*; et al.
JAERI-Tech 2005-021, 114 Pages, 2005/03
JAERI-Tech-2005-021.pdf:9.66MB
To perform the research and development for accelerator-driven system (ADS), Japan Atomic Energy Research Institute (JAERI) plans to build a Transmutation Experimental Facility under the JAERI-KEK joint J-PARC program. Transmutation Experimental Facility consists of two buildings, Transmutation Physics Experimental Facility to make reactor physics experiment with subcritical core, and ADS Target Test Facility for the preparation of irradiation database for various structural materials. In this report, purpose to build, experimental schedule, and design study of the ADS target test facility with drawer type spallation target are summarized.
Watanabe, Masayuki; Nankawa, Takuya*; Yamada, Teppei*; Kimura, Takaumi; Namiki, Kosuke*; Murata, Masaki*; Nishihara, Hiroshi*; Tachimori, Shoichi
Inorganic Chemistry, 42(22), p.6977 - 6979, 2003/11
Times Cited Count：34 Percentile：75.29(Chemistry, Inorganic & Nuclear)A tripodal ligand, tris(2-pyridyl)carbinol affords a novel tetradentate coordination mode in homodinuclear lanthanide complexes, which exhibit remarkably short distance between the metal ions. Strong fluorescence of Eu(III) and Tb(III) complexes with the ligand demonstrate that the ligand has a suitable excited state for energy transfer from the ligand to Eu(III) and Tb(III) center.
Iwanaga, Kohei; Yamane, Tsuyoshi; Nishihara, Kenji; Okajima, Shigeaki; Sekimoto, Hiroshi*; Asaoka, Takumi*
Proceedings of 11th International Conference on Nuclear Engineering (ICONE-11) (CD-ROM), 10 Pages, 2003/04
no abstracts in English
Wada, Atsushi; Watanabe, Masayuki; Yamanoi, Yoshinori*; Murata, Masaki*; Nishihara, Hiroshi*
no journal, ,
Lanthanide complexes with linear and cyclic octadentate oligopyridine-amine ligands were newly synthesized, and their molecular structures were determined by single-crystal X-ray crystallography. All of the complexes formed with the distorted CSAP geometry, the symmetry of which was higher for the complexes with the cyclic ligand than those with the linear ligand. The Eu and Tb complexes showed intense luminescence due to energy transfer from the ligand to the metal center (antenna effect). The Eu complexes with the linear ligand showed more intense emissions attributed to the 5D07F2 transition than the complex with the cyclic ligand, which can be explained by the decrease in symmetry around the lanthanide ion. The coordination of water molecules to Eu and Tb ions was strongly inhibited by surrounding the metal ions with the cyclic ligand, resulting in an appearance of intense luminescence in water. These results indicate that the symmetry and stability of lanthanide complexes, and thus the luminescence properties, can be successfully controlled by tuning the geometrical structures of multi-dentate ligands.
Watanabe, Masayuki; Nankawa, Takuya; Wada, Atsushi*; Namiki, Kosuke*; Murata, Masaki*; Nishihara, Hiroshi*; Kimura, Takaumi
no journal, ,
A tripodal ligand, tris(2-pyridyl)carbinol affords a novel tetradentate coordination mode in homodinuclear lanthanide complexes, which exhibit remarkably short distances between metal ions. Structures of dinuclear complexes synthesized from triflates exhibited the same structure other than the difference in the bond lengths which was induced by lanthanide contraction across the lanthanide series from Pr to Lu. In these complexes, the distance between two lanthanide ions was remarkably short. In this study the same type of dinuclear complexes were synthesized from nitrates. The nitrate ion can coordinate in both monodentate fand bidentate fashions. Since ionic radii are dependent upon the coordination number, nitrate could affect the metal-metal distance. In fact, dinuclear complexes exhibited longer distance between lanthanide ions than the triflates due to the increase of ionic radii of lanthanide ions. Some features of these dinuclear systems, which are induced from the difference of metal-metal distance, will be discussed in the presentation.
Watanabe, Masayuki; Ishimori, Kenichiro; Wada, Atsushi*; Kataoka, Yumiko*; Murata, Masaki*; Shinoda, Satoshi*; Nishihara, Hiroshi*; Tsukube, Hiroshi*; Kimura, Takaumi
no journal, ,
Soft-donor extractants containing sulfur- or nitrogen-donor are applicable to the separation of trivalent actinides (An(III)) from lanthanides (Ln(III)) by solvent extraction method. We designed two ligand systems which are expected to efficiently separate An(III) from Ln(III). The one is "Oligo-pyridine" ligand containing multiple pyridine moieties. The other is "Chirality-controlled" ligand containing chiral centers in the ligand. We synthesized more than thirty ligands and found out the ability on the separation of An(III) from Ln(III). In this presentation, we will discuss about the comprehensive results on the separation ability of An(III) from Ln(III) by means of "Oligo-pyridine" and "Chirality-controlled" ligands, and the extraction equilibrium of An(III) with selected tripodal ligands in detail.
N
nanoparticlesTamai, Yuta; Ishii, Yuya*; Hagiya, Hiroyuki; Kikuchi, Takayuki*; Yokoyama, Makoto*; Nishihara, Yoshikazu*; Takeda, Masayasu; Kakurai, Kazuhisa; Oku, Takayuki; Shinohara, Takenao; et al.
no journal, ,
Magnetic recording tape is widely used for a massive data storage with high reliability, and further increase of capacity, the recording density, is requested by IT organizations. The needle-shaped ferromagnetic metals has been used for the recording media. However, it is necessary to make the media a small and spherical shape to increase the recording density. We have performed the polarized neutron diffraction measurements of Fe
N round-shape nanoparticles, and determined the saturation magnetic moments and averaged core size of FeN nanoparticles covered by a laminate layer.
Hagiya, Hiroyuki; Oku, Takayuki; Kira, Hiroshi; Shinohara, Takenao; Suzuki, Junichi; Takeda, Masayasu; Tamai, Yuta; Kakurai, Kazuhisa; Sasaki, Yuji*; Kishimoto, Mikio*; et al.
no journal, ,
no abstracts in English
Hagiya, Hiroyuki; Oku, Takayuki; Kira, Hiroshi; Shinohara, Takenao; Suzuki, Junichi; Takeda, Masayasu; Kakurai, Kazuhisa; Yokoyama, Makoto*; Nishihara, Yoshikazu*; Oba, Yojiro*; et al.
no journal, ,
no abstracts in English
Hagiya, Hiroyuki; Oku, Takayuki; Kira, Hiroshi; Shinohara, Takenao; Suzuki, Junichi; Kakurai, Kazuhisa; Yokoyama, Makoto*; Nishihara, Yoshikazu*; Mamiya, Hiroaki*; Oba, Yojiro*; et al.
no journal, ,
no abstracts in English
Nishihara, Kenji; Iwamura, Takamichi*; Akie, Hiroshi; Shirasu, Noriko
no journal, ,
Use of Rock-like oxide (ROX) fuel is proposed for the purpose of reduction of plutonium amount in the case of gradually stopping nuclear power generation without introducing fast breeder reactors. In this study, the mass flow and repository of three scenarios that is once-through, Pu-thermal and ROX, was analysed. As the result, amount and attractiveness as nuclear weapon of Pu was decreased in the ROX scenario in comparison with the once-through scenario, although the repository size was not reduced.
Akie, Hiroshi; Shirasu, Noriko; Nishihara, Kenji; Iwamura, Takamichi*
no journal, ,
no abstracts in English
