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Hemmi, Ko; Walker, A.*; Yamaguchi, Tetsuji
Radiochimica Acta, 109(7), p.539 - 546, 2021/07
Times Cited Count:0 Percentile:0.00(Chemistry, Inorganic & Nuclear)Plutonium(IV) sorption onto quartz in carbonate solutions was systematically investigated under anaerobic conditions to analyze the sorption behaviors of Pu(IV) with a non-electrostatic model (NEM). Pu(IV) sorption data was obtained from batch sorption experiments as a function of pH and carbonate concentration. The Pu(IV) sorption onto quartz showed similar tendencies to Th(IV), which is considered to be chemically analogous as a tetravalent actinoid. The distribution coefficient, d, of Pu(IV) onto quartz showed inverse proportionality to the square of the total carbonate concentration under the investigated pH conditions of 8 to 11. The modeling study, however, revealed a Th(IV) sorption model, which is
SOTh(OH)
and
SOThOH(CO
)
, could not be applied to simulate the Pu(IV) sorption onto quartz. It was inferred that the electrostatic repulsion between negatively charged ligands limited the formation of
SOM(OH)
and
SOMOH(CO
)
for Pu(IV) with smaller ionic radii than Th(IV). The Pu(IV) sorption model was developed as
SOPu(OH)
and
SOPu(OH)
. In addition, data of Pu(IV) sorption onto muscovite was obtained in order to be compared with data for quartz.
Mukai, Yasunobu; Nakamichi, Hideo; Kobayashi, Daisuke; Nishimura, Kazuaki; Fujisaku, Sakae; Tanaka, Hideki; Isomae, Hidemi; Nakamura, Hironobu; Kurita, Tsutomu; Iida, Masayoshi*; et al.
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 8 Pages, 2017/04
TRP has stored the plutonium in solution state for long-term since the last PCDF operation in 2007 was finished. After the great east Japan earthquake in 2011, JAEA had investigated the risk against potential hazard of these solutions which might lead to make hydrogen explosion and/or boiling of the solution accidents with the release of radioactive materials to the public when blackout. To reduce the risk for storing Pu solution (about 640 kg Pu), JAEA planned to perform the process operation for the solidification and stabilization of the solution by converted into MOX powder at PCDF in 2013. In order to perform PCDF operation without adaption of new safety regulation, JAEA conducted several safety measures such as emergency safety countermeasures, necessary security and safeguards (3S) measures with understanding of NRA. As a result, the PCDF operation had stared on 28th April, 2014, and successfully completed to convert MOX powder on 3rd August, 2016 for about 2 years as planned.
Kobayashi, Fuyumi; Sumiya, Masato; Kida, Takashi; Kokusen, Junya; Uchida, Shoji; Kaminaga, Jota; Oki, Keiichi; Fukaya, Hiroyuki; Sono, Hiroki
JAEA-Technology 2016-025, 42 Pages, 2016/11
A preliminary test on MOX fuel dissolution for the STACY critical experiments had been conducted in 2000 through 2003 at Nuclear Science Research Institute of JAEA. Accordingly, the uranyl / plutonium nitrate solution should be reconverted into oxide powder to store the fuel for a long period. For this storage, the moisture content in the oxide powder should be controlled from the viewpoint of criticality safety. The stabilization of uranium / plutonium solution was carried out under a precipitation process using ammonia or oxalic acid solution, and a calcination process using a sintering furnace. As a result of the stabilization operation, recovery rate was 95.6% for uranium and 95.0% for plutonium. Further, the recovered oxide powder was calcined again in nitrogen atmosphere and sealed immediately with a plastic bag to keep its moisture content low and to prevent from reabsorbing atmospheric moisture.
Umeda, Miki; Nakazaki, Masato; Kida, Takashi; Sato, Kenji; Kato, Tadahito; Kihara, Takehiro; Sugikawa, Susumu
JAERI-Tech 2003-024, 23 Pages, 2003/03
MOX dissolution with silver mediated electrolytic oxidation method is planned for the preparation of plutonium nitrate solution to be used for criticality safety experiments at Nuclear Fuel Cycle Safety Engineering Research Facility (NUCEF). Silver mediated electrolytic oxidation method uses the strong oxidisation ability of Ag(II) ion. This method is thought to be effective for the dissolution of MOX, which is difficult to be dissolved with nitric acid.In this paper, the results of experiments on dissolution with 100 g of MOX are described. It was confirmed by the results that the MOX powder to be used at NUCEF was completely dissolved by silver mediated electrolytic oxidation method and that Pu(VI) ion in the obtained solution was reduced to tetravalent by means of NO purging.
Sakurai, Satoshi; Arakawa, Takuya*;
Journal of Nuclear Science and Technology, 35(5), p.365 - 369, 1998/05
Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)no abstracts in English
Sakurai, Satoshi; Tachimori, Shoichi
Journal of Nuclear Science and Technology, 33(2), p.187 - 189, 1996/02
Times Cited Count:23 Percentile:85.41(Nuclear Science & Technology)no abstracts in English
; Arai, Yasuo; Iwai, Takashi; Omichi, Toshihiko
Journal of Nuclear Science and Technology, 28(7), p.689 - 691, 1991/07
no abstracts in English
Takeshita, Isao; Nomura, Masayuki; ; Izawa, Naoki; Yanagisawa, Hiroshi
Proc. of the 3rd Int. Conf. on Nuclear Fuel Reprocessing and Waste Management,Vol. 1, p.510 - 515, 1991/00
no abstracts in English
; ; ;
Journal of Nuclear Science and Technology, 19(8), p.681 - 683, 1982/00
Times Cited Count:2 Percentile:43.36(Nuclear Science & Technology)no abstracts in English
Hemmi, Ko
no journal, ,
no abstracts in English