Study on electrolytic reduction of pertechnetate in nitric acid solution for electrolytic extraction of rare metals for future reprocessing

Asakura, Toshihide; Kim, S.-Y.; Morita, Yasuji; Ozawa, Masaki*

Journal of Nuclear and Radiochemical Sciences, 6(3), p.267 - 269, 2005/12

https://doi.org/10.14494/jnrs2000.6.3_267

An electrolytic extraction (EE) method, i.e. electro-reductive deposition, of Tc from nitric acid aqueous solution was studied for future reprocessing. After 30 min of constant potential electrolysis by carbon electrode at -0.3 V vs. SSE (Standard Silver Electrode), Tc concentration in 3 M nitric acid decreased to 93 % of the initial value, which corresponds to 7 % of deposition. With co-existence of Pd, the value reached to 15 % of deposition equivalent by electrolysis at 0.0 V vs. SSE for 60 min. An acceleration effect of Pd on Tc deposition (promoter effect) was suggested. The concentration, however, increased to the initial value after further electrolysis and competing re-dissolution of deposited Tc was also suggested. In cyclic voltammetry measurements, it was found that the deposit from Tc-Pd-Ru-Rh solution dissolved easier than that from Pd-Ru-Rh did. In electrolyzed Tc solution, an absorption peak at 482 nm was found. It can be attributed to the complex with nitrite anion, and the complex formation is proposed as one possible mechanism of Tc re-dissolution.

Electrochemical behaviors of PuN and (U, Pu)N in LiCl-KCl eutectic melts

Shirai, Osamu; Kato, Tetsuya*; Iwai, Takashi; Arai, Yasuo; Yamashita, Toshiyuki

Journal of Physics and Chemistry of Solids, 66(2-4), p.456 - 460, 2005/02

https://doi.org/10.1016/j.jpcs.2004.06.040

Electrochemical behaviors of PuN and (U, Pu)N in the LiCl-KCl eutectic melt containing UCl and PuCl at 773 K were investigated by cyclic voltammetry. The electrochemical dissolution of PuN and (U, Pu)N began nearly at -1.0 V vs. the Ag/AgCl reference electrode. The rest potentials of PuN and (U, Pu)N were observed at about 0.15 V more negative potential than that of UN since the equilibrium potential of UN is about 0.15 V more positive than that of PuN. In the cyclic voltammogram measured by using (U, Pu)N as the working electrode, a steep rise of the positive current was observed at more positive potential than -0.4 V in analogy with the cyclic voltammogram measured by using UN as the working electrode. In addition, there were two anodic current waves in the voltammogram with (U, Pu)N, though the wave form was not clear. This indicates that UN and PuN would be dissolved independently irrespective of formation of the solid solution, (U, Pu)N.

Principle of electrolytic chromatography and coulopotentiography and its application to flow-injection analysis

Yoshida, Zenko; Kihara, Sorin*; Fujinaga, Taichiro*

Bunseki Kagaku, 53(4), p.195 - 205, 2004/04

https://doi.org/10.2116/bunsekikagaku.53.195

A quantitative electrolysis of an electro-active species in a sample solution can be achieved very rapidly when the solution is allowed to flow through and be electrolyzed at a column electrode. Complete electrolysis of the species is attained with a small over-voltage, even if the electrode reaction is slow. The electrolytic method using the column electrode is suitable for automated or remote-controlled operation. Because of unmatched advantages, the column-electrode electrolysis method has been widely applied to the coulometric determination of species in a flowing sample solution and to liquid chromatography as a coulometric detector. This technique is especially favorable for elucidating mechanism of such complicated reactions as that involving unstable intermediates. In the present article, a principle and a feature of the column-electrode electrolysis are presented and the advantages of these methods are reviewed based on recent works on its application to flow-injection analysis and to a study of the redox reaction of actinide ions or the reaction of short-lived radicals.

Recovery of U by electrolysis of UN in LiCl-KCl eutectic melts

Shirai, Osamu; Uozumi, Koichi*; Iwai, Takashi; Arai, Yasuo

Journal of Nuclear Science and Technology, 39(Suppl.3), p.745 - 748, 2002/11

http://www.tandfonline.com/doi/abs/10.1080/00223131.2002.10875574

no abstracts in English

Design study of feasible water detritiation systems for fusion reactor of ITER scale

Iwai, Yasunori; Yamanishi, Toshihiko; Okuno, Kenji; Yokogawa, Nobuhisa*; *; Yoshida, Hiroshi; O.K.Kveton*

Journal of Nuclear Science and Technology, 33(12), p.981 - 992, 1996/12

https://doi.org/10.3327/jnst.33.981

no abstracts in English

Hydrogen-methanol production system using nuclear process heat

; Omoto, Akira*; *; *; *; *; *; *; *; *; et al.

Enerugi, Shigen Gakkai Dai-11-Kai Kenkyu Happyokai Koen Rombunshu, p.33 - 38, 1992/00

no abstracts in English

Developments of tritium technology for next-step fusion devices under JAERI-DOE(LANL) collaboration

Naruse, Yuji; Okuno, Kenji; Yoshida, Hiroshi; Konishi, Satoshi; Anderson, J. L.*; Bartlit, J. R.*

Journal of Nuclear Science and Technology, 27(12), p.1081 - 1095, 1990/12

https://doi.org/10.3327/jnst.27.1081

no abstracts in English

High temperature gas-cooled reactor and its utilization

Netsu Enerugi Shohi To Chikyu Kankyo Hogo No Hohoron, p.173 - 187, 1990/05

no abstracts in English

Isotope effects in electrolytic formation of lithium amalgam

Fujie, Makoto; *; *; *

Journal of Nuclear Science and Technology, 23(4), p.330 - 337, 1986/00

https://doi.org/10.3327/jnst.23.330

no abstracts in English