Continuous liquid-liquid extraction of uranium from uranium-containing wastewater using an organic phase-refining-type emulsion flow extractor

Nagano, Tetsushi; Naganawa, Hirochika; Suzuki, Hideya; Toshimitsu, Masaaki*; Mitamura, Hisayoshi*; Yanase, Nobuyuki*; Grambow, B.

Analytical Sciences, 34(9), p.1099 - 1102, 2018/09

https://doi.org/10.2116/analsci.18N002

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.

Simple cation-exchange separation for ICP-MS measurement of Se in spent nuclear fuel sample

Asai, 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

Analyses of assay data of LWR spent nuclear fuels with a continuous-energy Monte Carlo code MVP and JENDL-4.0 for inventory estimation of Se, Tc, Sn and Cs

Okumura, 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

https://doi.org/10.15669/pnst.2.369

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.

Computational study for inventory estimation of Se-79, Tc-99, Sn-126, and Cs-135 in high-level radioactive wastes from spent nuclear fuels of light water reactors

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

https://doi.org/10.1115/ICEM2011-59087

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.

Post irradiation examination analyses with a continuous-energy Monte Carlo code MVP for long-lived fission products in LWR spent fuels

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.

Determination of long-lived radionuclide in spent nuclear fuel; Anion-exchange separation of tin for Sn determination

Toshimitsu, 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

Study on recovery of useful elements from simulated radioactive liquid waste by photo-reduction

Oba, Hironori; Saeki, Morihisa; Toshimitsu, Masaaki

no journal, , 

The recovery characteristics of useful elements such as platinum group metals from a simulated radioactive solution by photo-reduction using an UV-vis light were experimentally examined. A 10-components simulated solution was prepared by dissolving known amounts of metallic compounds (Ru, Rh, Pd, Mo, Zr, Ba, Sr, Cs, Nd) and sodium in nitric acid of 3 mol/l. The metallic palladium was selectively recovered from the simulated solution containing TiO-photocatalyst, while other elements mainly remained in solution. The recovery efficiency of Pd increased with the increase of the TiO concentration and was more than 99% at a TiO concentration above 2 g/l.

High sensitive analysis of elements in aqueous solution by using laser-induced breakdown spectroscopy

Oba, Hironori; Toshimitsu, Masaaki; Saeki, Morihisa; Tanabe, Rie*; Ito, Yoshiro*; Wakaida, Ikuo

no journal, , 

no abstracts in English

Development of in-vessel inspection technology using remote imaging and spectroscopy, 2; Development of laser-induced breakdown spectroscopy technique for solid samples submerged in water

Toshimitsu, Masaaki; Saeki, Morihisa; Sugiyama, Akira; Oba, Hironori; Thornton, B.*; Sakka, Tetsuo*

no journal, , 

no abstracts in English

Development of remote laser-induced breakdown spectroscopy for samples submerged in water

Toshimitsu, Masaaki; Saeki, Morihisa; Oba, Hironori; Thornton, B.*; Sakka, Tetsuo*

no journal, , 

A laser-induced breakdown spectroscopy (LIBS) technique for element analysis of samples submerged in water using a fiber optic light delivery set-up has been developed. The set-up delivers air to the sample surface via a tube and uses the same fiber optic for laser light delivery, and for observation of the light emitted by the micro-plasma generated for analysis. The emission spectra from metals, alloys and oxide samples such as Fe, SUS304, zircaloy-2, ZrO can be clearly observed at wavelengths ranging from 730 nm to 870 nm.