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Yamagishi, Isao; Nagaishi, Ryuji; Kato, Chiaki; Morita, Keisuke; Terada, Atsuhiko; Kamiji, Yu; Hino, Ryutaro; Sato, Hiroyuki; Nishihara, Kenji; Tsubata, Yasuhiro; et al.
Journal of Nuclear Science and Technology, 51(7-8), p.1044 - 1053, 2014/07
Times Cited Count:16 Percentile:76.9(Nuclear Science & Technology)For safe storage of zeolite wastes generated by treatment of radioactive saline water at the Fukushima Daiichi Nuclear Power Station, properties of the Herschelite adsorbent were studied and its adsorption vessel was evaluated for hydrogen production and corrosion. Hydrogen production depends on its water level and dissolved species because hydrogen is oxidized by radicals in water. It is possible to evaluate hydrogen production rate in Herschelite submerged in seawater or pure water by taking into account of the depth effect of the water. The reference vessel of decay heat 504 W with or without residual pure water was evaluated for the hydrogen concentration by thermal hydraulic analysis using obtained fundamental properties. Maximum hydrogen concentration was below the lower explosive limit (4 %). The steady-state corrosion potential of a stainless steel 316L increased with absorbed dose rate but its increase was repressed by the presence of Herschelite. At 750 Gy/h and 60C which were values evaluated at the bottom of the vessel of 504 W, the localized corrosion of SUS316L contacted with Herschelite would not immediately occur under 20,000 ppm of Cl concentration.
Chen, R.*; Tanaka, Hisashi*; Kawamoto, Toru*; Asai, Miyuki*; Fukushima, Chikako*; Na, H.*; Kurihara, Masato*; Watanabe, Masayuki; Arisaka, Makoto; Nankawa, Takuya
Electrochimica Acta, 87, p.119 - 125, 2013/01
Times Cited Count:104 Percentile:94.98(Electrochemistry)A novel electrochemical adsorption system using a nanoparticle film of copper (II) hexacyanoferrate (III) was proposed for selectively removing cesium from wastewater. This system can be used for cesium separation without extra chemical reagents or any filtration treatment. Cesium uptake and elution can be simply controlled by switching the applied potentials between anodes and cathodes. Data from batch kinetic studies well fitted the intraparticle diffusion equation, reflecting a two-step process: a steepest ascent portion followed by a plateau extending to the equilibrium. The effective cesium removal with a high distribution coefficient ( 510 mL/g) can be adopted in a large pH range from 0.3 to 9.2, and in the presence of several diverse coexisting alkaline cations, suggesting it can be taken as a promising technology for actual nuclear wastewater treatment.
Yamagishi, Isao; Nagaishi, Ryuji; Terada, Atsuhiko; Kamiji, Yu; Kato, Chiaki; Morita, Keisuke; Nishihara, Kenji; Tsubata, Yasuhiro; Ji, W.*; Fukushima, Hisashi*; et al.
IAEA-CN-211 (Internet), 5 Pages, 2013/01
Since the accident at Fukushima Daiichi Nuclear Power Station, a large amount of radioactive contaminated water has been generated to cool damaged reactor cores. Adsorption of cesium with zeolite-like media was employed for treatment of this contaminated saline water. As spent zeolite media are highly radioactive, their safe storage is a pressing issue. Japan Atomic Energy Agency has extensively conducted R&D on the management of secondary wastes produced by the operation of the treatment system. Subjects on the safe storage of spent zeolites include the analysis of their characteristics and the evaluation of effectiveness of the present safety measures in consideration of decay heat emission and hydrogen generation by water radiolysis as well as durability of vessels exposed to saline. Preliminary results obtained are described in the present paper.
Chen, R.*; Tanaka, Hisashi*; Kawamoto, Toru*; Asai, Miyuki*; Fukushima, Chikako*; Kurihara, Masato*; Watanabe, Masayuki; Arisaka, Makoto; Nankawa, Takuya
Electrochemistry Communications, 25, p.23 - 25, 2012/11
Times Cited Count:49 Percentile:79.98(Electrochemistry)We first synthesized water-dispersed nanoparticle copper hexacyanoferrate (CuHCF) ink and then coated its nanoparticles on electrodes to electrochemically remove cesium from wastewater. Cesium uptake and elution can be controlled by switching the potentials between anodes and cathodes. Effective cesium removal can be adopted in a large pH range from 0.2 to 8.9, and in the presence of several diverse coexisting alkaline cations, suggesting that it can be taken as a promising technology for actual radioactive wastewater treatment. The prepared CuHCF nanoparticles can be simply and uniformly coated on electrodes by wet process like conventional printing methods, so any sizes or patterns are feasible at low cost, which indicated the potential as a promising sorption electrode of large size in the columns for sequential removal and recycle of Cs from wastewater.
Takemoto, Hiroki*; Fukushima, Masahiro; Chiba, Satoshi; Horiuchi, Hisashi*; Akaishi, Yoshinori*; Tosaki, Akihiro*
Physical Review C, 69(3), p.035802_1 - 035802_9, 2004/03
Times Cited Count:29 Percentile:81.07(Physics, Nuclear)no abstracts in English
Tanaka, Hisashi*; Kawamoto, Toru*; Asai, Miyuki*; Fukushima, Chikako*; Kurihara, Masato*; Arisaka, Makoto; Nankawa, Takuya; Watanabe, Masayuki
no journal, ,
The adsorption/desorption of cesium, which was included in the radioactive liquid waste was controlled by electrodes which were made by nanoparticle ink of hexacyano ferrous salts. As a result, we will report the development on the recovery method which was reusable.
Tanaka, Hisashi*; Asai, Miyuki*; Fukushima, Chikako*; Kawamoto, Toru*; Kurihara, Masato*; Arisaka, Makoto; Nankawa, Takuya; Watanabe, Masayuki
no journal, ,
Copper hexacyanoferrate complex could be repetitively adsorb cesium cation in terms of electrochemical reduction and oxidation. We demonstrated the adsorption performance of the thin membrane electrode which copper hexacyanoferrate complex was formed on a metal electrode and also attempted thickening of the copper hexacyanoferrate complex layer on the electrode. The copper hexacyanoferrate complex electrochemically adsorbed about 90% of Cs from the solution by 4 times repetition of the adsorption cycle. The electrochemical efficiency of the adsorption increased 50 times by thickening of the copper hexacyanoferrate complex layer on the electrode.
Ji, W.*; Fukushima, Hisashi*; Sato, Seichi*; Kozaki, Tamotsu*; Yamagishi, Isao; Nishihara, Kenji
no journal, ,
no abstracts in English
Fukushima, Hisashi*; Ji, W.*; Sato, Seichi*; Kozaki, Tamotsu*; Yamagishi, Isao; Nishihara, Kenji
no journal, ,
no abstracts in English
Tanaka, Hisashi*; Chen, R.*; Fukushima, Chikako*; Na, H.*; Asai, Miyuki*; Kawamoto, Toru*; Kurihara, Masato*; Arisaka, Makoto; Nankawa, Takuya; Watanabe, Masayuki
no journal, ,
Hexacyanoferrate complex could repeatedly adsorb and desorb cesium by electrochemical reduction and oxidation. We have recently developed to form a film on a metal electrode in terms of nano particle of the hexacyano ferrate complex "ink". The optimum condition of the electrochemical adsorption and desorption under the acidic condition would be reported in the present study.
Ji, W.*; Fukushima, Hisashi*; Sato, Seichi*; Watanabe, Naoko*; Kozaki, Tamotsu*; Yamagishi, Isao; Nishihara, Kenji; Terada, Atsuhiko
no journal, ,
no abstracts in English
Fukushima, Hisashi*; Sato, Seichi*; Watanabe, Naoko*; Kozaki, Tamotsu*; Yamagishi, Isao; Nishihara, Kenji
no journal, ,
no abstracts in English
Tanaka, Hisashi*; Chen, R.*; Asai, Miyuki*; Fukushima, Chikako*; Kawamoto, Toru*; Ishizaki, Manabu*; Kurihara, Masato*; Arisaka, Makoto; Nankawa, Takuya; Watanabe, Masayuki
no journal, ,
Hexacyanoferrate metal Complex (MHCF) is well-known as adsorption materials for Cesium ion. We have developed the effective processing method by making MHCF of nano particle ink. In this paper, we investigated the effect of the presence of other metal cations on electrochemical adsorption and desorption of cesium.
Chen, R.*; Tanaka, Hisashi*; Fukushima, Chikako*; Asai, Miyuki*; Kawamoto, Toru*; Kurihara, Masato*; Ishizaki, Manabu*; Arisaka, Makoto; Nankawa, Takuya; Watanabe, Masayuki
no journal, ,
Transition metal hexacyanoferrates (MHCFs) are preferred to be competitive ion exchangers over other materials due to their selectivity and high capacity. CuHCF has been much used as precipitants for alkali metal cations, especially cesium, to remove them from aqueous radioactive wastes. Instated of the conventional adsorption by using copper hexacyanoferrate powder, we developed and coated the CuHCF nanoparticles on the electrode substance, and then performed Cs removal in an electrochemical column System. The objective of this study was to develop a nanoparticle film of CuHCF for Cs removal and to suggest a promising column technology for sequential removal of actual radiocesium wastewater.