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Journal Articles

Characteristics of TPDN/SiO$$_{2}$$-P adsorbent for MA(III) recovery

Kofuji, Hirohide; Watanabe, So; Takeuchi, Masayuki; Suzuki, Hideya; Matsumura, Tatsuro; Shiwaku, Hideaki; Yaita, Tsuyoshi

Progress in Nuclear Science and Technology (Internet), 5, p.61 - 65, 2018/11

Journal Articles

Report on International Conference; Actinides 2017

Haga, Yoshinori; Yamamura, Tomoo*

Nippon Genshiryoku Gakkai-Shi, 60(3), P. 181, 2018/03

no abstracts in English

Journal Articles

Thermodynamic equilibrium constants for important isosaccharinate reactions; A Review

Rai, D.*; Kitamura, Akira

Journal of Chemical Thermodynamics, 114, p.135 - 143, 2017/11

 Times Cited Count:2 Percentile:78.74(Thermodynamics)

Isosaccharinic acid is a cellulose degradation product that can form in low-level nuclear waste repositories and is known to form strong complexes with many elements, including actinides, disposed of in these repositories. We (1) reviewed the available data for deprotonation and lactonisation constants of isosaccharinic acid, and the isosaccharinate binding constants for Ca, Fe(III), Th, U(IV), U(VI), Np(IV), Pu(IV), and Am(III), (2) summarized complexation constant values for predicting actinide behavior in geologic repositories in the presence of isosaccharinate, and (3) outlined additional studies to acquire reliable thermodynamic data where the available data are inadequate.

Journal Articles

Research and development for accuracy improvement of neutron nuclear data on minor actinides

Harada, Hideo; Iwamoto, Osamu; Iwamoto, Nobuyuki; Kimura, Atsushi; Terada, Kazushi; Nakao, Taro; Nakamura, Shoji; Mizuyama, Kazuhito; Igashira, Masayuki*; Katabuchi, Tatsuya*; et al.

EPJ Web of Conferences (Internet), 146, p.11001_1 - 11001_6, 2017/09

 Times Cited Count:1 Percentile:14.04

Journal Articles

Application of FE-SEM to the measurement of U, Pu, Am in the irradiated MA-MOX fuel

Sasaki, Shinji; Tanno, Takashi; Maeda, Koji

Proceedings of 54th Annual Meeting of Hot Laboratories and Remote Handling (HOTLAB 2017) (Internet), 6 Pages, 2017/00

During irradiation in a fast reactor, the microstructure change of the mixed oxide fuels and the changes of element distributions occur because of a radial temperature gradient. Therefore, it is important to study the irradiation behavior of MA-MOX for advancement of fast reactor fuels. In order to make detailed observations of microstructure and elemental analyses of MA-MOX, irradiated MA-MOX specimens were carried out PIE by using a FE-SEM equipped with WDX. Because fuel samples have high radio activities and emit alpha-particles, the instrument was modified. the instrument was installed in a lead shield box and the control unit was separately located outside the box. The microstructure changes were observed in irradiated MA-MOX specimen. The characteristic X-rays peaks were detected successfully. By measuring the intensities of characteristic X-rays, it was tried quantitative analysis of U, Pu, Am along radial direction of irradiated specimen.

Journal Articles

Flow-sheet study of MA recovery by extraction chromatography for SmART cycle project

Watanabe, So; Nomura, Kazunori; Kitawaki, Shinichi; Shibata, Atsuhiro; Kofuji, Hirohide; Sano, Yuichi; Takeuchi, Masayuki

Procedia Chemistry, 21, p.101 - 108, 2016/12

BB2015-3215.pdf:0.34MB

 Times Cited Count:2 Percentile:7.84

Journal Articles

Development of nitride fuel cycle technology for transmutation of minor actinides

Hayashi, Hirokazu; Nishi, Tsuyoshi*; Sato, Takumi; Kurata, Masaki

Proceedings of 21st International Conference & Exhibition; Nuclear Fuel Cycle for a Low-Carbon Future (GLOBAL 2015) (USB Flash Drive), p.1811 - 1817, 2015/09

Transmutation of long-lived radioactive nuclides including minor actinides (MA: Np, Am, Cm) has been studied in Japan Atomic Energy Agency (JAEA). Accelerator-driven system (ADS) is regarded as one of the powerful tools for transmutation of MA under the double strata fuel cycle concept. Uranium-free nitride fuel was chosen as the first candidate fuel for MA transmutation using ADS. To improve the transmutation ratio of MA, reprocessing of spent fuel and reusing MA recovered from the spent fuels is necessary. Our target is to transmute 99% of MA arisen from commercial power reactor fuel cycle, with which the period until the radiotoxicity drops below that of natural uranium can be shorten from about 5000 years to about 300 years. A pyrochemical process has been proposed as the first candidate for reprocessing of the spent nitride fuel. This paper overviews the current status of the nitride fuel cycle technology. Our recent study on fuel fabrication, fuel property measurements, reprocessing of spent fuel, development of the property database of MA nitride fuel, and fuel behavior simulation code are introduced. Our research and development (R&D) plan based on the roadmap of the development is also introduced.

Journal Articles

Socio-economic effects of the material science in JAERI

Yanagisawa, Kazuaki; Takahashi, Shoji*

Scientometrics, 78(3), p.505 - 524, 2008/10

 Times Cited Count:1 Percentile:71.44(Computer Science, Interdisciplinary Applications)

A socio-economic evaluation of Material Science (MS) of JAERI was made. The goal was to reveal the emphasized basic research fields (EBRF) of MS and to observe its socio-economic networking. High ranked keywords for the former and the number of co-authored papers for the latter were used along with many MS related papers. The obtained results are: (1) The EBRF of MS of JAERI were typically represented by the keywords of ion irradiation, actinides, etc., i.e., those having a strong relation to the nuclear field. Regarding actinides, the socio-economic networking between JAERI and PS occurred at the growth rate of 3-4% per 25 years, but 8% during the past 5 years. This implies that the research cooperation between the two was markedly enhanced. (2) The EBRF of MS between JAERI and 5 selected research bodies (SRB) represented by Tokyo University was directly compared and revealed that only 7 keywords as typically represented by neutron and accelerators. After overlapping, JAERI and SRB seem to be raising the national standard level.

Journal Articles

Extraction separation of Am(III) and Eu(III) with TPEN isomers and decanoic acid

Matsumura, Tatsuro; Takeshita, Kenji*

ACS Symposium Series, 933, p.261 - 273, 2006/07

Three TPEN isomers with different positon of nitrogen donor in pyridyl groups, t2pen, t3pen and t4pen, were synthesized and the extraction separation of Am(III) and Eu(III) with these ligands and a fatty acid, decanoic acid, was investigated. All isomers were similar in the complexation in the aqueous phase, such as the protonation and the formation of metal complex, however, they showed different extraction behavior of Am and Eu. The synergistic extraction effect for Am was observed for t2pen and the high separation factor about 100 was measured, when 1:2. The value is comparable to that for the extraction system with a famous nitrogen-donor extractant, BTP. On the other hand, the extractability of other isomers was very low and no separation of Am and Eu was observed. Only t2pen, in which nitrogen donor in pyridyl groups is positioned in the vicinity of the skeletal structure (N-C-C-N structure) of ligand, is available for the extraction separation of Am.

JAEA Reports

Research and development on partitioning in JAERI; Review of the research activities until the development of 4-group partitioning process

Morita, Yasuji; Kubota, Masumitsu*

JAERI-Review 2005-041, 35 Pages, 2005/09

JAERI-Review-2005-041.pdf:2.24MB

Research and development on Partitioning in JAERI are reviewed in the present report from the beginning to the development of the 4-Group Partitioning Process and its test with real high-level liquid waste (HLLW). In the 3-Group Partitioning Process established in around 1980, elements in HLLW are separated into 3 groups of transuranium element group, Sr-Cs group and the other element group. The 4-Group Partitioning Process subsequently developed contains the separation of Tc-platinum group metals additionally. The process was tested to demonstrate its performance with real concentrated HLLW. Until then, various separation methods for various elements were studied and selection and optimization of the separation methods were carried out to establish the process. Review of the experience, findings and results is very important and valuable for future study on partitioning. The present report is prepared from this point of view.

Journal Articles

Selective separation of Am(III) from Ln(III) with a novel synergistic extraction system, N,N,N',N'-tetrakis(2-methylpyridyl)ethylenediamine (TPEN) and carboxylic acid in 1-octanol

Mirvaliev, R.*; Watanabe, Masayuki; Matsumura, Tatsuro; Tachimori, Shoichi*; Takeshita, Kenji*

Journal of Nuclear Science and Technology, 41(11), p.1122 - 1124, 2004/11

 Times Cited Count:18 Percentile:21.09(Nuclear Science & Technology)

Transmutation is a technology aimed to reduce HLW from reprocessing process. Minor actinides in the HLW will be converted to short-lived nuclides. However, lanthanides in HLW adversely affects on the efficiency of the transmutation. It is well known that separating An(III) and Ln(III) is very difficult because of their similarity of chemical properties. Therefore, the separation is one of the essential subjects to establish the transmutation technology. Considerable efforts have been devoted to the development of new extractants for the separation. N,N,N',N'-tetrakis(2-methylpyridyl)ethylenediamine (TPEN) demonstrates 100-fold preference for Am(III) over Ln(III) between stability constants with the ions in the aqueous phase. We have reported that Am(III) was selectively extracted from the aqueous phase containing Ln(III) by TPEN in nitrobenzene system and synergistic system with TPEN and D2EHPA in octanol. This work presents our recent results that Am(III) is separated from Eu(III) by a synergistic extraction system with TPEN and decanoic acid diluted with 1-octanol.

JAEA Reports

Evaluation of socio-economic effects of R&D results at Japan Atomic Energy Research Institute, 2; Socio-economic evaluation of the basic research at JAERI

The Ad Hoc Committee for Evaluation of R&D Achievements

JAERI-Review 2003-036, 75 Pages, 2003/11

JAERI-Review-2003-036.pdf:9.68MB

no abstracts in English

JAEA Reports

Proceedings of the Symposium on the Joint Research Project between JAERI and Universities "Backend Chemistry for Fuel Cycle" and "Advanced Radiation Application Research"; Results of the 4th Phase Joint Research Project and the Future Plan, February 18, 2003, The University of Tokyo, Sanjyo Hall

Committee for the Joint Research Project between JAERI and Universities; Committee for the Universities' JAERI Collaborative Research

JAERI-Conf 2003-015, 103 Pages, 2003/11

JAERI-Conf-2003-015.pdf:8.92MB

The present report describes the Proceedings of the Symposium on the Joint Research Project between JAERI and Universities - Results of the 4th Phase Joint Research Project and the Future Plan -, held at the University of Tokyo on February 18, 2003. The joint research project composed of the backend chemistry project and the advanced radiation application project was to be concluded in the end of March 2003. Hence the symposium was held in order to review the results obtained in the 4th phase project and to exchange ideas on the effective measures for the future joint collaboration in view of the past activities.

Journal Articles

Fabrication of nitride fuels for transmutation of minor actinides

Minato, Kazuo; Akabori, Mitsuo; Takano, Masahide; Arai, Yasuo; Nakajima, Kunihisa; Ito, Akinori; Ogawa, Toru

Journal of Nuclear Materials, 320(1-2), p.18 - 24, 2003/09

 Times Cited Count:45 Percentile:5.17

In the Japan Atomic Energy Research Institute, the concept of the transmutation of minor actinides (MA: Np, Am and Cm) with accelerator-driven systems is being studied. The MA nitride fuel has been chosen as a candidate because of the possible mutual solubility among the actinide mononitrides and excellent thermal properties besides supporting hard neutron spectrum. MA nitrides of AmN, (Am,Y)N, (Am,Zr)N and (Cm0.4Pu0.6)N were prepared from the oxides by the carbothermic reduction method. The prepared MA nitrides were examined by X-ray diffraction and the contents of impurities of oxygen and carbon were measured. The fabrication conditions for MA nitrides were improved so as to reduce the impurity contents. For an irradiation test of U-free nitride fuels, pellets of (Pu,Zr)N and PuN+TiN were prepared and a He-bonded fuel pin was fabricated. The irradiation test started in May 2002 and will go on for two years in the Japan Materials Testing Reactor.

Journal Articles

Research and development on nuclear transmutation, B; Transmutation fuel and reprocessing

Minato, Kazuo; Arai, Yasuo

Genshikaku Kenkyu, 47(6), p.31 - 38, 2003/06

no abstracts in English

Journal Articles

Validation of minor actinide cross sections by studying samples irradiated for 492 days at the dounreay prototype fast reactor, 2; Burnup calculations

Tsujimoto, Kazufumi; Kono, Nobuaki; Shinohara, Nobuo; Sakurai, Takeshi; Nakahara, Yoshinori; Mukaiyama, Takehiko; Raman, S.*

Nuclear Science and Engineering, 144(2), p.129 - 141, 2003/06

To evaluate neutron cross-section data of minor actinides, separated actinide samples and dosimetry samples were irradiated at the Dounreay Prototype Fast Reactor for 492 effective full power days. Based on the burnup calculations of major actinide and dosimetry samples, the neutron flux distribution and the flux level were adjusted at the locations where minor actinide samples were irradiated. The burnup calculations were carried out for minor actinides using the determined flux distribution and flux level. This paper discusses the burnup calculations and the validation of minor actinide cross-section data in evaluated nuclear data libraries. We find that we can obtain reliable FIMA (fission per initial metallic atom) values by using the $$^{148}$$Nd method except that the uncertainties in the FIMA values are large for $$^{234}$$U, $$^{238}$$Pu, Am isotopes, and Cm isotopes because the $$^{148}$$Nd yields are known poorly for these isotopes and are probably overestimated. For these isotopes, measurements to improve the fission-yield data are needed. We also find that, in general, the JENDL-3.2 nuclear data for the minor actinides are adequate for the conceptual design study of transmutation systems. But, there are some nuclides (especially $$^{238}$$Pu and $$^{242}$$Pu) for which new measurements are needed particulary if the minor actinides constitute a major part of the nuclear fuel.

Journal Articles

Validation of minor actinide cross sections by studying samples irradiated for 492 days at the dounreay prototype fast reactor, 1; Radiochemical analysis

Shinohara, Nobuo; Kono, Nobuaki; Nakahara, Yoshinori; Tsujimoto, Kazufumi; Sakurai, Takeshi; Mukaiyama, Takehiko*; Raman, S.*

Nuclear Science and Engineering, 144(2), p.115 - 128, 2003/06

no abstracts in English

Journal Articles

Validation of minor actinide cross sections by studying samples irradiated for 492 days at the dounreay prototype fast reactor, 1; Radiochemical analysis

Shinohara, Nobuo; Kono, Nobuaki; Nakahara, Yoshinori; Tsujimoto, Kazufumi; Sakurai, Takeshi; Mukaiyama, Takehiko*; Raman, S.*

Nuclear Science and Engineering, 144(2), p.115 - 128, 2003/06

 Times Cited Count:7 Percentile:49.5(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Validation of minor actinide cross sections by studying samples irradiated for 492 days at the dounreay prototype fast reactor, 2; Burnup calculations

Tsujimoto, Kazufumi; Kono, Nobuaki; Shinohara, Nobuo; Sakurai, Takeshi; Nakahara, Yoshinori; Mukaiyama, Takehiko*; Raman, S.*

Nuclear Science and Engineering, 144(2), p.129 - 141, 2003/06

 Times Cited Count:9 Percentile:38.54(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Preparation of novel silica-based R-BTP extraction-resins and their application to trivalent actinides and lanthanides separation

Wei, Y.*; Hoshi, Harutaka*; Kumagai, Mikio*; Asakura, Toshihide; Uchiyama, Gunzo*

Journal of Nuclear Science and Technology, 39(Suppl.3), p.761 - 764, 2002/11

To separate long-lived minor actinides and specific fission products such as Zr and Mo from nitrate acidic high-level liquid waste, we studied an advanced partitioning process by extraction chromatography using minimal organic solvent and compact equipment. In this work, we synthesized several new type of nitrogen donor ligands, 2,6-bi-(5,6-dialkyl-1,2,4-triazine-3-yl)-pyridine (R-BTP) with different alkyl groups and prepared novel silica-based extraction-resins by impregnating these ligands into the SiO$$_{2}$$-P support with a diameter of 50 $$mu$$m. The adsorption performance of $$^{243}$$Am and Ln (III) from nitrate solution was investigated. It was found that the adsorption behavior depends strongly on the alkyl group in R-BTP. ${it n}$Bu-BTP/SiO$$_{2}$$-P and ${it n}$Hex-BTP/SiO$$_{2}$$-P showed high absorbability and selectivity for Am (III) over Ln (III). The separation factor is about 10$$^{4}$$ for Am/Ce and near 10$$^{2}$$ for Am/Eu-Gd, respectively. Effective Am (III) separation form Ln (III) by extraction chromatography using R-BTP/SiO$$_{2}$$-P extraction-resins is expected.

49 (Records 1-20 displayed on this page)