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Nagano, Tetsushi; Naganawa, Hirochika; Suzuki, Hideya; Toshimitsu, Masaaki*; Mitamura, Hisayoshi*; Yanase, Nobuyuki*; Grambow, B.
Analytical Sciences, 34(9), p.1099 - 1102, 2018/09
Times Cited Count：12 Percentile：45.06(Chemistry, Analytical)A previously reported emulsion flow (EF) extraction system does not include a device for refining used solvent. Therefore, the processing of large quantities of wastewater by using the EF extractor alone could lead to the accumulation of wastewater components into the solvent and diminished extraction performance. In the present study, we have developed a solvent-washing-type EF system, which is equipped with a unit for washing used solvent to prevent accumulation, and successfully applied it for treating uranium-containing wastewater.
Sn content in spent nuclear fuel sampleAsai, Shiho; Toshimitsu, Masaaki; Hanzawa, Yukiko; Suzuki, Hideya; Shinohara, Nobuo; Inagawa, Jun; Okumura, Keisuke; Hotoku, Shinobu; Kimura, Takaumi; Suzuki, Kensuke*; et al.
Journal of Nuclear Science and Technology, 50(6), p.556 - 562, 2013/06
Times Cited Count：11 Percentile：63.81(Nuclear Science & Technology)The Sn content in a spent nuclear fuel solution was determined by ICP-MS for its inventory estimation in high-level radioactive waste. An irradiated UO
fuel was used as a sample to evaluate the reliability of the methodology. Prior to the measurement, Sn was separated from Te, which causes major isobaric interference in the determination of Sn content, along with highly radioactive coexisting elements using an anion-exchange column. The absence of counts attributed to Te in the Sn-containing effluent indicates that Te was completely removed. After washing, Sn retained on the column was readily eluted with 1 M HNO
. The isotope ratios of Sn were successfully determined and showed good agreement with those obtained through ORIGEN2 calculations. The results reported in this paper are the first experimental values of Sn content in the spent nuclear fuel solution originating in spent nuclear fuel irradiated at a nuclear power plant in Japan.
Kojima, Kensuke; Okumura, Keisuke; Asai, Shiho; Hanzawa, Yukiko; Okamoto, Tsutomu; Toshimitsu, Masaaki; Inagawa, Jun; Kimura, Takaumi; Kaneko, Satoru*; Suzuki, Kensuke*
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 5 Pages, 2011/12
Accurate inventory estimation of long-lived fission products (LLFPs) in LWR spent fuels is important for the quality management and for long-term safety assessment of high-level radioactive vitrified wastes. In Japan, ORIGEN2 has been widely used to estimate the fuel compositions. However, equipped library data in the original ORIGEN2 are old and are not validated enough for LLFPs, such as 
Se, 
Tc, Sn and 
Cs, because available post irradiation examination (PIE) data are limited for these nuclides, which have difficulties in radiochemical analyses. For more accurate the estimation, new ORIGEN2 libraries are developed from the latest nuclear data library JENDL-4.0 for cross sections and fission yields, and from other libraries for half-lives, and so on. The new libraries are validated by PIE analyses of the sample fuels irradiated in Cooper, Calvert-Cliffs-1, H. B. Robinson-2, and Ohi-1. As a result, it was found that the new library gives good results for the estimation.
Se in spent nuclear fuel sampleAsai, Shiho; Hanzawa, Yukiko; Suzuki, Hideya; Toshimitsu, Masaaki; Okumura, Keisuke; Shinohara, Nobuo; Kimura, Takaumi; Inagawa, Jun; Suzuki, Kensuke*; Kaneko, Satoru*
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 5 Pages, 2011/12
Se, Tc, Sn and CsOkumura, Keisuke; Asai, Shiho; Hanzawa, Yukiko; Suzuki, Hideya; Toshimitsu, Masaaki; Inagawa, Jun; Okamoto, Tsutomu; Shinohara, Nobuo; Kaneko, Satoru*; Suzuki, Kensuke*
Progress in Nuclear Science and Technology (Internet), 2, p.369 - 374, 2011/10
For accurate inventory estimation of long-lived fission products in LWR spent fuels, a new burn-up chain model and decay data based on the latest nuclear data such as JENDL-4.0 was developed. MVP-BURN with the latest nuclear data was applied to several post irradiation examinations including inventory measurements of Se, Tc, Sn and Cs. One of them is a new measurement by JAEA. From the PIE analyses, it is found that the new PIE data obtained by JAEA is consistent with the other PIE data by different laboratory with different techniques. It is also confirmed that the present calculation results show good agreements with experimental ones within about 10% for productions of Se and Cs. In contrast, amounts of Tc and Sn are overestimated by about 50%. These discrepancies are likely due to the effect of insoluble residue produced during sample dissolution and/or errors of fission yields in the analyses.
Okumura, Keisuke; Asai, Shiho; Hanzawa, Yukiko; Okamoto, Tsutomu; Suzuki, Hideya; Toshimitsu, Masaaki; Inagawa, Jun; Kimura, Takaumi; Suzuki, Kensuke*; Kaneko, Satoru*
Proceedings of 14th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2011) (CD-ROM), p.1443 - 1450, 2011/09
Inventory estimation of long-lived fission products (LLFPs) in high-level radioactive wastes (HLW) from spent nuclear fuels of light water reactors is important for a safety assessment of their disposal. In order to develop an inventory estimation method of difficult-to-measure LLFPs (Se-79, Tc-99, Sn-126, and Cs-135), a parametric study was carried out by using a sophisticated burnup calculation code and data. In the parametric study, fuel specifications and irradiation conditions are changed in the conceivable range. The considered parameters are fuel assembly types (PWR / BWR), U-235 enrichment, moderator temperature, void fraction, power density, and so on. From the calculated results, we clarify the burnup characteristics of the target LLFPs and their possible ranges of generations. Finally, candidates of the key nuclide are proposed for the scaling factor method of HLW.
Asai, Shiho; Okumura, Keisuke; Hanzawa, Yukiko; Suzuki, Hideya; Toshimitsu, Masaaki; Inagawa, Jun; Kimura, Takaumi; Kaneko, Satoru*; Suzuki, Kensuke*
Proceedings of 14th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2011) (CD-ROM), p.1437 - 1442, 2011/09
Asai, Shiho; Hanzawa, Yukiko; Okumura, Keisuke; Suzuki, Hideya; Toshimitsu, Masaaki; Shinohara, Nobuo; Kaneko, Satoru*; Suzuki, Kensuke*
Proceedings of 13th International Conference on Environmental Remediation and Radioactive Waste Management (ICEM 2010) (CD-ROM), p.261 - 264, 2010/10
Okumura, Keisuke; Asai, Shiho; Hanzawa, Yukiko; Suzuki, Hideya; Toshimitsu, Masaaki; Inagawa, Jun; Katakura, Junichi; Shinohara, Nobuo; Kaneko, Satoru*; Suzuki, Kensuke*
Proceedings of Joint International Conference of 7th Supercomputing in Nuclear Application and 3rd Monte Carlo (SNA + MC 2010) (USB Flash Drive), 5 Pages, 2010/10
For accurate inventory estimation of long-lived fission products in LWR spent fuels, a new burn-up chain model and decay data based on the latest nuclear data were developed for MVP-BURN. They were applied to three post irradiation examinations including inventory measurements of Se, Tc, Sn and Cs. One of them is new measurements performed by JAEA. From the PIE analyses, it is found that the new measurements by JAEA are consistent with the other PIE data obtained by different laboratory with different techniques. It is also confirmed that the present calculation results show good agreements with experimental ones for Se and Cs within about 10%. In contrast, amounts of Tc and Sn are overestimated by about up to 50%. These discrepancies are likely due to the effect of insoluble residue in the measurements and/or errors of fission yields in the analyses.
Saeki, Morihisa; Toshimitsu, Masaaki; Oba, Hironori
no journal, ,
One ton of high-level radioactive waste (HLRW) that is generated from nuclear power plant contains a few kilograms of refractory and platinum-group metals, such as Mo, Zr and Pd. Separation of refractory and platinum-group metals from HLRW contributes to smooth operation of vitrification process. On the other hand, titanium oxide materials adsorb metals by ion-exchange function and micronize metals by photocatalyst function. In this work, we attempted to separate the refractory and platinum-group metals from simulated solution of HLRW by using the titanium oxide nanoparticles, and investigate dependence of recovery efficiency on the particle size.
Kochiyama, Mami; Ishimori, Kenichiro; Toshimitsu, Masaaki; Katayama, Atsushi; Saito, Naoaki*; Omura, Hideki*; Takahashi, Kuniaki
no journal, ,
no abstracts in English
Saeki, Morihisa; Toshimitsu, Masaaki; Oba, Hironori
no journal, ,
We proposed separation technique of platinum-group metals (PGMs) from a solution of high-level radioactive waste by using laser-induced particle formation, and performed its proof-of-principle experiment. The simulated solution of high-level radioactive liquid wastes (HLLW) was prepared by dissolving Pd, Rh, Ru and neodymium (Nd) into distilled water. The Nd metal was added as representative of lanthanide and minor actinide. After 40-min irradiation of an UV laser to mixture of the simulated solution of HLLW and ethanol, the Pd, Rh and Ru metals were separated from the Nd ion as particle with sub-micron size. The Pd, Rh and Ru metals were recovered with efficiency of 100%, 94-99%, 65-69%, while the Nd ion was completely kept in the sample solution. Moreover, we investigated dependence of recovery efficiency on various experimental parameters. The results suggest mutual separation of Pd and Rh by arrangement of the intensity of the irradiation laser.
Oba, Hironori; Saeki, Morihisa; Toshimitsu, Masaaki; Wakaida, Ikuo; Tanabe, Rie*; Ito, Yoshiro*
no journal, ,
We investigated the feasibility of laser-induced breakdown spectroscopy (LIBS) for the determination of elements in a liquid solution in the form of a jet flow and using nanosecond laser pulses. A comparison of LIBS sensitivity between two types of flows for liquid analysis was performed. A pipette nozzle tip was used to create a columnar flow of 520
m diameter, whereas a trapezoidal-shaped groove nozzle tip produced an ultrathin sheet flow of 5
40m thickness. The limit of detection of Na atoms was estimated to be about 14 ng/mL by use of the columnar flow, whereas 1.1 ng/mL in the case of the sheet flow.
Wakaida, Ikuo; Oba, Hironori; Oba, Masaki; Matsumoto, Ayumu; Ruas, A.; Toshimitsu, Masaaki; Akaoka, Katsuaki; Miyabe, Masabumi
no journal, ,
For the decommissioning of "Fukushima Daiichi Nuclear Power Station", Optical Fiber based LIBS probe is constructed, and under water condition, we have successfully observed some specific spectra from the simulated sample of molten debris made by sintered oxide of Zr and U. For the use of more longer optical fiber, long-pulse laser with the pulse duration about 100 ns will be introduced to compensate the delivery power loss and/or to enhance the emission signal to be about several times by the time integration of emission signal. As for the signal enhancement technique, microwave assisted LIBS technique coupled with simple antenna for the combination use with fiber LIBS will be under developing, and about ten times enhancement was observed under the atmosphere condition. For the application to the liquid phase sample, especially for the analysis of the polluted cooling water, the thin-sheet liquid jets will be also introduced as the convenience and high sensitive monitoring for dissolved elements of nuclear fuel debris.
Matsumoto, Ayumu; Oba, Hironori; Toshimitsu, Masaaki; Akaoka, Katsuaki; Wakaida, Ikuo
no journal, ,
Matsumoto, Ayumu; Oba, Hironori; Toshimitsu, Masaaki; Akaoka, Katsuaki; Wakaida, Ikuo
no journal, ,
no abstracts in English
Matsumoto, Ayumu; Oba, Hironori; Toshimitsu, Masaaki; Akaoka, Katsuaki; Wakaida, Ikuo
no journal, ,
no abstracts in English
Oba, Hironori; Matsumoto, Ayumu; Toshimitsu, Masaaki; Akaoka, Katsuaki; Wakaida, Ikuo
no journal, ,
no abstracts in English
Sn determinationToshimitsu, Masaaki; Asai, Shiho; Hanzawa, Yukiko; Suzuki, Hideya; Inagawa, Jun; Okumura, Keisuke; Shinohara, Nobuo; Kimura, Takaumi; Kaneko, Satoru*; Suzuki, Kensuke*
no journal, ,
no abstracts in English
Matsumoto, Ayumu; Oba, Hironori; Toshimitsu, Masaaki; Akaoka, Katsuaki; Wakaida, Ikuo
no journal, ,
no abstracts in English
