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Yoshigoe, Akitaka; Shiwaku, Hideaki; Kobayashi, Toru; Shimoyama, Iwao; Matsumura, Daiju; Tsuji, Takuya; Nishihata, Yasuo; Yaita, Tsuyoshi; Kogure, Toshihiro*; Motai, Satoko*; et al.
no journal, ,
Pinpoint chemical analysis for Cs-adsorbed vermiculite was performed by using synchrotron radiation photoelectron emission microscopy (SR-PEEM). It was found that Cs is distributed through the micro-size clay particles and we also succeeded to measure pinpoint X-ray absorption spectra for constituent element simultaneously. Furthermore, we precisely confirmed the existence of Fe in the sample.
Tsukada, Chie*; Yoshida, Hikaru; Ogawa, Satoshi*; Yoshigoe, Akitaka; Yagi, Shinya*; Yaita, Tsuyoshi
no journal, ,
The decontamination of radioactive Cs from the soil and the water has been required in Fukushima. Gold nanoparticles (AuNPs) are attractive candidate for Cs adsorbent. AuNPs fabricated by solution plasma method is not covered by dispersant and is almost clean. It is known that L-cysteine rapidly adsorbs and exists with high density on the AuNPs surface. The electrostatic attractive force may be useful to induce interactions between -COO- of L-cysteine and Cs ion in aqueous solution. This study reveals the adsorption reaction between the Cs and the Cys/AuNP. Cys/AuNP has a peak and CsCl/Cys/AuNP has no peak in Na 1s spectra. Cys/AuNP has no peak and CsCl/Cys/AuNP has a peak for Cs 3 spectra. From these results, Na on Cys/AuNP is replaced by Cs after reaction in CsCl aqueous solution. Cys/AuNP and CsCl/Cys/AuNP have a O 1s peak, where the peak position of CsCl/Cys/AuNP is higher than that ofCys/AuNP. This indicates the further polarization of -COO- by replacing Na by Cs.
Kato, Chiaki; Sato, Tomonori; Yamagishi, Isao; Arisaka, Makoto; Terada, Atsuhiko
no journal, ,
Electrochemical test of stainless steel (SUS316L) in zeolite containing artificial seawater under gamma-ray irradiation as a basic study on the local corrosion generation conditions of the used adsorption tower used for contaminated water treatment at the Fukushima Daiichi Nuclear Power Plant Accident. In addition, a drying test using the second Cs adsorption tower (SARRY) mock-up was conducted to report the change of Cl concentration in the tower and to investigate the possibility of local corrosion in the used Cs adsorption tower. The steady natural immersion potential of stainless steel became noble by gamma irradiation, and the potential increased as the absorbed dose rate increased. On the other hand, in the zeolite coexisting system, the potential increase under gamma irradiation was suppressed. The mechanism of increasing the potential of stainless steel under gamma irradiation is that HO generated by radiation activates the cathode reaction of stainless steel and that the potential of zeolite decreases to suppress the formation of HO. Also, from the dry test of the mock-up specimen, as the temperature of the zeolite layer rises, the residual water is sucked up by the dry zeolite layer, so that the salt content of the residual water is precipitated in the heat generating part and the evaporated water condenses on the inner surface of the container. It was confirmed that the residual water Cl concentration decreased due to the heat generation in the adsorption tower, which was confirmed by the mock-up test specimen. It was expected as a mitigation measure.
Matsui, Naoki*; Okubo, Takahiro*; Tachi, Yukio; Sugiura, Yuki; Yotsuji, Kenji*
no journal, ,
no abstracts in English