Optical properties of trinuclear citrate complexes containing 4f and 5f block metals

Aoyagi, Noboru; Palladino, G.*; Nagasaki, Shinya*; Kimura, Takaumi

Bulletin of the Chemical Society of Japan, 91(6), p.882 - 890, 2018/06

https://doi.org/10.1246/bcsj.20170419

The speciation and coordination geometries of M(III)-citrate complexes in aqueous solutions, where M denotes Eu, Tb, Lu, or Cm, are studied using potentiometric titration, nuclear magnetic resonance spectroscopies. Their photophysical properties are also characterized by time-resolved fluorescence spectra. The formation constants of mononuclear, dinuclear, and trinuclear Lu-citrate species were determined by potentiometric titration in 3.00 M NaClO aqueous media. Terminal carboxylic conformation in trinuclear complexes comprised both the five- and six-membered rings at different exchanging rates. Hydration states evaluated for Eu ions are the chemical formula of [Eu(Cit) (H O) ] and [Eu(OH)(Cit)(HO)]. These complexes in aqueous solution have geometrical similarity to the crystal structures in the literature. Furthermore, the entity of the hetero-trinuclear complex induces the intramolecular energy transfer from Tb to Eu. The incorporation of Cm into these homo/hetero-trinuclear citrate complexes proved to be a successful trial to probe the formation of actinide polymer at a trace level.

Symposium on "Science of nuclear fuel cycle and backend; Research and education" with a memory of Professor Joonhong Ahn, the University of California, Berkeley

Nakayama, Shinichi; Okumura, Masahiko*; Nagasaki, Shinya*; Enokida, Yoichi*; Umeki, Hiroyuki*; Takase, Hiroyasu*; Kawasaki, Daisuke*; Hasegawa, Shuichi*; Furuta, Kazuo*

Genshiryoku Bakkuendo Kenkyu (CD-ROM), 23(2), p.131 - 148, 2016/12

http://nuce.aesj.or.jp/jnuce/vol23/Jnuce-Vol23-2-p131-148.pdf

A symposium "Science of nuclear fuel cycle and backend - Research and education -" was held at the Univer-sity of Tokyo in June 25, 2016. This aimed at developing the research on nuclear fuel cycle and backend. The time and the number of participants of the symposium were limited, but the active discussion was conducted, and the common perception for the future was shared among the experienced participants in those fields. This paper provides the discussions made in the symposium, and also, as a memory to Professor Ahn, the University of California, Berkeley, his prominent achievements in academic research and education.

One-dimensional analysis of ECRH-assisted plasma start-up in JT-60SA

Hada, Kazuyoshi*; Nagasaki, Kazunobu*; Masuda, Kai*; Kobayashi, Shinji*; Ide, Shunsuke; Isayama, Akihiko; Kajiwara, Ken

Fusion Science and Technology, 67(4), p.693 - 704, 2015/05

https://doi.org/10.13182/FST14-811

no abstracts in English

Operation regime development

Suzuki, Takahiro; Nagasaki, Kazunobu*

Purazuma, Kaku Yugo Gakkai-Shi, 88(11), p.657 - 659, 2012/11

AA2012-0600.pdf:0.39MB

http://ci.nii.ac.jp/naid/110009554631

no abstracts in English

Analysis of ECRH pre-ionization for plasma start-up in JT-60SA

Hada, Kazuyoshi*; Nagasaki, Kazunobu*; Masuda, Kai*; Kinjo, Ryota*; Ide, Shunsuke; Isayama, Akihiko

Plasma and Fusion Research (Internet), 7(Sp.1), p.2403104_1 - 2403104_5, 2012/07

https://doi.org/10.1585/pfr.7.2403104

no abstracts in English

Burning of MOX fuels in LWRs; Fuel history effects on thermal properties of hull and end piece wastes and the repository performance

Hirano, Fumio; Sato, Seichi*; Kozaki, Tamotsu*; Inagaki, Yaohiro*; Iwasaki, Tomohiko*; Oe, Toshiaki*; Kato, Kazuyuki*; Kitayama, Kazumi*; Nagasaki, Shinya*; Niibori, Yuichi*

Journal of Nuclear Science and Technology, 49(3), p.310 - 319, 2012/03

AA2011-0278.pdf:0.56MB

https://doi.org/10.1080/00223131.2012.660021

The thermal impacts of hull and end piece wastes from the reprocessing of MOX spent fuels burned in LWRs on repository performance were investigated. The heat generation rates in MOX spent fuels and the resulting heat generation rates in hull and end piece wastes change depending on the fuel histories including the burn-up of UO spent fuels, the cooling period before reprocessing, the storage period of fresh MOX fuels. The heat generation rates of hull and end piece wastes from the reprocessing of MOX spent fuels with any of those histories are significantly larger than those from UO spent fuels with burn-ups of 45 GWd/THM. If a temperature below 80C is specified for cement-based materials used in waste packages after disposal, the allowable number of canisters containing compacted hull and end pieces in a package for 45 GWd-MOX needs to be limited to a value of 0.7 to 1.6, which is significantly lower than the value of 4.0 for 45 GWd-UO.

Recent research activities on breakdown and start-up towards future superconducting large tokamaks

Maekawa, Takashi*; Ide, Shunsuke; Kajiwara, Ken; Nagasaki, Kazunobu*; Isayama, Akihiko; Hada, Kazuyoshi*

Purazuma, Kaku Yugo Gakkai-Shi, 87(10), p.671 - 681, 2011/10

http://ci.nii.ac.jp/naid/110008750645

no abstracts in English

Application of parallel factor analysis for time-resolved laser fluorescence spectroscopy; Implication for metal speciation study

Saito, Takumi*; Sao, Hirokazu*; Ishida, Keisuke*; Aoyagi, Noboru; Kimura, Takaumi; Nagasaki, Shinya*; Tanaka, Satoru*

Environmental Science & Technology, 44(13), p.5055 - 5060, 2010/07

https://doi.org/10.1021/es9036995

Basic actinide chemistry and physics research in close cooperation with hot laboratories; ACTILAB

Minato, Kazuo; Konashi, Kenji*; Fujii, Toshiyuki*; Uehara, Akihiro*; Nagasaki, Shinya*; Otori, Norikazu*; Tokunaga, Yo; Kambe, Shinsaku

IOP Conference Series; Materials Science and Engineering, 9, p.012018_1 - 012018_7, 2010/05

https://doi.org/10.1088/1757-899X/9/1/012018

Basic research in actinide chemistry and physics is indispensable to maintain sustainable development of innovative nuclear technology. Actinides, especially minor actinides of americium and curium, need to be handled in special facilities with containment and radiation shields. To promote and facilitate the actinide research, close cooperation with the facilities and sharing of technical and scientific information must be very important and effective. A three-year-program "Basic actinide chemistry and physics research in close cooperation with hot laboratories", ACTILAB, was started to form the bases of sustainable development of innovative nuclear technology. In this program, researches on actinide solid-state physics, solution chemistry and solid-liquid interface chemistry are made using four main facilities in Japan in close cooperation with each other, where basic experiments with transuranium elements can be made. The O-NMR measurements were performed on (PuAm)O to study the electronic state and the chemical behaviour of Am and Cm ions in electrolyte solutions was studied by distribution experiments.

Neutron powder diffraction and difference maximum entropy method analysis of protium- and deuterium-dissolved BaSnInO

Nagasaki, Takanori*; Shiotani, Shinya*; Igawa, Naoki; Yoshino, Masahito*; Iwasaki, Kota*; Fukazawa, Hiroshi; Utsumi, Wataru

Journal of Solid State Chemistry, 182(10), p.2632 - 2639, 2009/10

https://doi.org/10.1016/j.jssc.2009.06.024

We propose a new method, a difference maximum entropy method (MEM) analysis of the neutron diffraction data, for revealing the detailed structure around hydrogen atoms in proton-conducting oxides. This MEM analysis uses the differences between the structure factors of protium- and deuterium-dissolved crystals. Simulations demonstrate that it not only provides the distribution of hydrogen atoms alone, but also improves the spatial resolution of MEM mapping around hydrogen atoms. Applied to actual diffraction data of protium- and deuterium-dissolved BaSnInO at 9 K, difference MEM analysis reveals that O-D bonds mostly tilt towards the second nearest oxygen atoms, and that the distributions of deuterium and oxygen atoms are probably insignificant in interstitial regions.