Application of vibrational sum frequency generation spectroscopy to studies of chemical reactions on water surface and actinide interface chemistry

Kusaka, Ryoji

Bunko Kenkyu, 72(4), p.155 - 162, 2023/08

Vibrational sum frequency generation (VSFG) spectroscopy is an optical second-order nonlinear vibrational spectroscopy using ultrashort pulse lasers. Because VSFG spectroscopy is a unique and powerful tool for studying molecular structures of interfaces, it has been widely used in many research fields. However, there still undoubtedly remains some VSFG research areas that have not studied well, partly because VSFG measurements are not so easily performed in comparison with relatively general spectroscopy methods. This review presented recent applications of VSFG spectroscopy to two research topics: (1) chemical reactions on water surfaces, and (2) actinide chemistry.

Interface atom mobility and charge transfer effects on CuO and CuO formation on CuPd(111) and CuPt(111)

Tsuda, Yasutaka; Gueriba, J. S.*; Makino, Takamasa*; Dio, W. A.*; Yoshigoe, Akitaka; Okada, Michio*

Scientific Reports (Internet), 11, p.3906_1 - 3906_8, 2021/02

https://doi.org/10.1038/s41598-021-82180-w

Chemical trapping of Sr vapor species by Zircaloy cladding under a specific chemical condition

Mohamad, A.*; Nakajima, Kunihisa; Suzuki, Eriko; Miwa, Shuhei; Osaka, Masahiko; Oishi, Yuji*; Muta, Hiroaki*; Kurosaki, Ken*

Proceedings of International Topical Workshop on Fukushima Decommissioning Research (FDR 2019) (Internet), 4 Pages, 2019/05

In the accident of Fukushima Daiichi Nuclear Power Station, formation of a volatile SrCl could have occurred by the sea-water injection into the core. This can cause the release of non-volatile group Sr from the fuel to induce chemical reactions with reactor structural materials, such as stainless steel and Zircaloy (Zry) cladding. Such reactions could cause the changes in distribution of Sr in the reactor. Chemical reactions between Sr species and Zry were therefore investigated experimentally. As the result, it can be said that Sr vapor species were chemically trapped right after the release from fuel. This trapping effect of Sr by Zry-cladding implies a possibility of preferable Sr retention in the oxide phase of debris.

Research and development on chemical reactors made of industrial structural materials and hydriodic acid concentration technique for thermochemical hydrogen production IS process

Kubo, Shinji; Iwatsuki, Jin; Takegami, Hiroaki; Kasahara, Seiji; Tanaka, Nobuyuki; Noguchi, Hiroki; Kamiji, Yu; Onuki, Kaoru

JAEA-Technology 2015-028, 32 Pages, 2015/10

JAEA-Technology-2015-028.pdf:23.69MB

JAEA has been conducting a study on IS process for thermochemical hydrogen production in order to develop massive hydrogen production technology for hydrogen society. Integrity of the chemical reactors and concentration technology of hydrogen iodide in HIx solution were studied. In the former study, the chemical reactors were trial-fabricated using industrial materials. A test of 30 times of thermal cycle test under circulating condition of the Bunsen reaction solution showed integrity of the Bunsen reactor made of fluororesin lined steel. Also, 100 hours of reaction tests showed integrity of the sulfuric acid decomposer made of silicon carbide and of the hydrogen iodide decomposer made of Hastelloy C-276. In the latter study, concerning electro-electrodialysis using cation-exchange membrane, sulfuric acid in the anolyte had little influence on the concentration performance. These results suggest the purification system of HIx solution can be simplified. Based on the Nernst-Planck equation and the Smoluchowski equation, proton transport number, water permeance, and IR drop of the cation exchange membrane were formulated. The derived equations enable quantitative estimation for the performance indexes of Nafion membrane and, also, of ETFE-St membranes made by radiation-induced graft polymerization method.

Comparative molecular simulation studies of oxidation reactions and hydrogen release for zirconium metals and silicon carbide under severe accident conditions

Machida, Masahiko; Nakamura, Hiroki; Srinivasan, S. G.*; Van Duin, A. C. T.*

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 4 Pages, 2015/05

Zircalloy has been widely employed as an excellent material covering the fuel rod. The mechanical and thermal properties have been explored by various experiments. In terms of its use as the fuel cladding, its response to oxidation reactions is an important topic when it is exposed to high temperature and high pressure steam during severe accidents. Especially, the hydrogen production accompanied by the oxidation is critical because it can lead to the crisis of the hydrogen explosion, as observed in the Fukushima Nuclear Power Plant accidents. Silicon carbide (SiC) has been considered as an alternative cladding material owing to an advantage that hydrogen production is much suppressed in the equivalent condition compared to Zircalloy. Therefore, we simulate the oxidation reaction for both materials, i.e. Zirconium metal and SiC in atomistic level by using the ReaxFF reactive force field method to simulate the chemical reaction molecular dynamics. Through such comparative studies between Zirconium and SiC in the same condition, we clarify how the temperature and the steam pressure accelerates the oxidation reaction and the resultant hydrogen production in both materials at typical severe accident conditions. The advantage using ReaxFF is that it allows us to directly trace the oxygen diffusion inside the Zirconium metal and SiC depending on the temperature and vapor pressure together with the oxidation reaction. We can compare the reaction processes in both materials. Especially, we paid attention to the rate of hydrogen production in both materials.

Experimental and modeling study to predict long-term alteration of bentonite buffer materials with alkaline groundwater

Takazawa, Mayumi; Negishi, Kumi; Sakamoto, Yoshifumi; Akai, Masanobu; Yamaguchi, Tetsuji; Iida, Yoshihisa; Tanaka, Tadao; Nakayama, Shinichi

JAERI-Conf 2005-007, p.236 - 241, 2005/08

https://jopss.jaea.go.jp/pdfdata/JAERI-Conf-2005-007.pdf

no abstracts in English

Modeling of variation in permeability of compacted bentonite with alkaline fluid for long-term safety assessment of geological disposal system

Takazawa, Mayumi; Yamaguchi, Tetsuji; Sakamoto, Yoshifumi; Akai, Masanobu; Tanaka, Tadao; Nakayama, Shinichi

NUMO-TR-04-05, p.A3_59 - A3_62, 2004/10

no abstracts in English

Radiochemical reactions between tritium oxides and carbon monoxide

Shu, Wataru; Ohira, Shigeru; Suzuki, Takumi; Nishi, Masataka

Fusion Engineering and Design, 70(2), p.123 - 129, 2004/02

https://doi.org/10.1016/j.fusengdes.2003.09.001

As a study on radiochemical reactions in the process of tritium recovery from the in-vessel components of future deuterium-tritium fusion machine like ITER beta-induced reactions in a N-balanced system of tritium oxides (TO/TO) with CO were examined by laser Raman, Fourier transition infrared (FT-IR) and mass spectroscopy. The depletion of CO follows a first-order reaction with a rate constant of 0.02 day, whereas the formation of CO is a complex process whose rate constant decreases from 2 day to 0.02 day. The main species on the 49th day after mixing CO are the produced CO and the balanced gas (N) in the gaseous phase, and the tritiated water predominates in the condensed phase. Tritiated substances like aldehyde, alcohol and carboxylic acid found in T-CO system were not detected in the products of reactions between tritium oxides and carbon monoxide at the same detection limit.

Present status and future subjects of the analytical studies related with application of charged particles and RI to materials science and biotechnology

Working Group in the Advisory Committee of the Analytical Studies for Application of Charged Particl

JAERI-Review 2003-008, 42 Pages, 2003/03

JAERI-Review-2003-008.pdf:3.12MB

The position in the research field of radiation application of "Theoretical Analysis Group for Radiation Application" which will be set up within fiscal 2003, and the relation between the research that this analytical group will advance in future and the analytical research made so far at JAERI Takasaki are summarized. First, the theoretical analysis group for radiation application extracts only the core element from the analysis of reactive process of charged particles in the materials and from the irradiation effect, and then constructs the simplified model. Second, the validity of the constructed model is verified by advancing the theoretical analysis based on the model, and the calculated result is fed back to the experiment, and then the verification is carried out. Finally, the general-purpose theorization will be conducted by generalizing and universalizing the obtained model concerning the specific system. The obtained outcomes will be applied to other systems, and, will consequently, contribute to the promotion of new technological development.

Initial oxidation states on Si(001) surface induced by translational kinetic energy of O at room temperature studied by Si-2p core-level spectroscopy using synchrotron radiation

Yoshigoe, Akitaka; Teraoka, Yuden

Surface Science, 482-485(Part.1), p.189 - 195, 2001/06

no abstracts in English