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Journal Articles

Spectrochemistry of technetium by liquid electrode plasma optical emission spectrometry and its applicability of quantification for highly active liquid waste

Yamamoto, Masahiko; Do, V. K.; Taguchi, Shigeo; Kuno, Takehiko; Takamura, Yuzuru*

Spectrochimica Acta, Part B, 155, p.134 - 140, 2019/05

The emission spectra of technetium (Tc) by liquid electrode plasma optical emission spectrometry have been investigated in this study. From the spectra, 52 emission peaks of Tc were observed in the 250-500 nm wavelength range. All peaks were assigned to the neutral state or singly ionized state. The relative intensities of these peaks were similar to those excited by an electric spark. The strongest intensity peaks were found at 254.3 nm, 261.0 nm, and 264.7 nm. Spectral interferences of coexisting elements in highly active liquid waste of reprocessing stream on those three strongest peaks were investigated using simulated sample. No spectral interferences were observed around the 264.7 nm Tc peak. Therefore, analytical performance using 264.7 nm peak was evaluated. The detection limit, estimated on standard and blank samples in 0.4 M nitric acid, was 1.9 mg/L. The relative standard deviation of Tc standard sample (12.0 mg/L) was 3.8% (N = 5, 1$$sigma$$).

Journal Articles

Effect of surface conditions of the filament used in thermal ionization mass spectrometry on an uranium isotopic measurement

Taguchi, Shigeo; Miyauchi, Hironari*; Horigome, Kazushi; Yamamoto, Masahiko; Kuno, Takehiko

Bunseki Kagaku, 67(11), p.681 - 686, 2018/11

In thermal ionization mass spectrometry, de-gassing is one of the important treatments to release impurities of filaments and to minimize the influence of background. In this work, the effect of the surface change in the tungsten filament induced by the conductively heating treatment on uranium isotopic ($$^{235}$$U/$$^{238}$$U) measurement has been investigated. It was found that the conductively heating treatment of the filament has the effect of smoothing the surface of the filament and also has the effect of improving the deposition of the sample on the filament surface. As a result of either these effects, the precision of uranium isotopic ($$^{235}$$U/$$^{238}$$U) measurement was improved.

Journal Articles

Separation technique using column chromatography for safeguards verification analysis of uranium and plutonium in highly-active liquid waste by isotope dilution mass spectrometry

Yamamoto, Masahiko; Taguchi, Shigeo; Horigome, Kazushi; Kuno, Takehiko

Proceeding IAEA Symposium on International Safeguards; Building Future Safeguards Capabilities (Internet), 8 Pages, 2018/11

In this study, the single-column extraction chromatographic separation has been developed for analysis of U and Pu in highly active liquid waste by isotope dilution mass spectrometry (IDMS). The commercially available TEVA$$^{textregistered}$$ resin is selected as an extraction chromatography resin. The U is chromatographically separated from fission products (FP) elements by nitric acid while Pu(IV) is adsorbed on the resin. After that, Pu is eluted by reducing to Pu(III). The method has been successfully achieved the separation with yielding the enough recovery and sufficient decontamination factors for subsequent IDMS analysis. The column dose rate after the FP removal is decreased to the background. The analytical results obtained by the developed method are in a good agreement with those of the conventional method. It provides simple and rapid separation and expected that the method can be applied to join IAEA/Japan on-site analytical laboratory.

JAEA Reports

Development of separation technique of Pu, Am, Np using solid phase extraction resin for the determination of impurity metal elements in plutonium nitrate solution by inductivity coupled plasma optical emission spectrometry

Taguchi, Shigeo; Yamamoto, Masahiko; Furuse, Takahiro*; Masaki, Yuji*; Kuno, Takehiko

JAEA-Technology 2018-005, 14 Pages, 2018/06

JAEA-Technology-2018-005.pdf:0.94MB

The method to remove Pu, Am and Np from plutonium nitrate solution recovered from spent nuclear fuel prior to ICP-OES measurement has been developed for the determination of 18 impurity metal elements (Fe, Cr, Ni, Mn, Al, Cd, V, Cu, Si, Zn, Mo, Sn, Ca, Mg, Na, Ag, Pb, B). In this method, two TRU resin packed columns were used for separation. In the first column, Pu and Am were mainly removed by adsorption. The recovered solution from the fist column was added to the second column after reduction of Np, and Am(III) and Np(IV) were removed by adsorption. The Pu nitrate solution (22g/L) of 2mL were treated by proposed method. The alpha emission nuclide was decreased to $$<$$5.8 Bq/mL in a solution diluted to 100mL. As a result of ICP-OES measurement, the recoveries of impurity metals separated by proposed method were almost 100%. This separation scheme can apply to the metal impurity elemental analysis in Pu nitrate solution recovered from spent nuclear fuel.

Journal Articles

Quantitative determination of total cesium in highly active liquid waste by using liquid electrode plasma optical emission spectrometry

Do, V. K.; Yamamoto, Masahiko; Taguchi, Shigeo; Takamura, Yuzuru*; Surugaya, Naoki; Kuno, Takehiko

Talanta, 183, p.283 - 289, 2018/06

 Times Cited Count:1 Percentile:62.19(Chemistry, Analytical)

We develop a novel analytical method employing liquid electrode plasma optical emission spectrometry for measurement of total cesium in highly active liquid wastes. Limit of detection and limit of quantification are 0.005 mg/L and 0.02 mg/L, respectively. The method is validated and applied to the real samples.

Journal Articles

Online coupling of two-phase flow solvent extraction microfluidics with inductively coupled plasma mass spectrometry

Do, V. K.; Yamamoto, Masahiko; Taguchi, Shigeo; Kuno, Takehiko; Surugaya, Naoki

Current Analytical Chemistry, 14(2), p.111 - 119, 2018/00

A direct coupling of two-phase flow solvent extraction microfluidics with ICP-MS for element-selective analysis is successfully established. Two-phase flow in microchannels of two combined glass chips for continuous extraction and back-extraction is stabilized through balancing the pressure by using an external coiled tube that functions as a flow resistor. The difference of fluid flow rate between microchannels and ICP-MS is adjusted by a proposed interface system including T-junction mixer and a switching valve. An online measurement of rhenium is successfully demonstrated. The calibration curve for Re is carried out in the range of 1 $$mu$$g/L to 20 $$mu$$g/L. The limit of detection is 0.2 $$mu$$g/L with a needed sample volume of one milliliter. Total time including extraction, back-extraction, and measurement is less than one hour. The development of the online coupling is a first step towards future applications to the selective measurement of highly radioactive elements.

Journal Articles

Replacement of the glove port equipped with glove box in Nuclear Fuel Reprocessing Facility

Horigome, Kazushi; Taguchi, Shigeo; Nishida, Naoki; Goto, Yuichi; Inada, Satoshi; Kuno, Takehiko

Nippon Hozen Gakkai Dai-14-Kai Gakujutsu Koenkai Yoshishu, p.381 - 384, 2017/08

no abstracts in English

JAEA Reports

Preparation of uranium and plutonium mixed spike optimized for MOX analysis by isotope dilution mass spectrometry

Horigome, Kazushi; Taguchi, Shigeo; Yamamoto, Masahiko; Kuno, Takehiko; Surugaya, Naoki

JAEA-Technology 2017-016, 20 Pages, 2017/07

JAEA-Technology-2017-016.pdf:1.68MB

Mixed spikes of uranium and plutonium have been prepared for the determination of uranium and plutonium in dissolved MOX solution by isotope dilution mass spectrometry. Enriched uranium metal NBL CRM116 and plutonium metal NBL CRM126 were accurately weighed and then dissolved in nitric acid, respectively. Their dissolved solutions were mixed in a mass ratio of 1 to 2. The preparation values of uranium and plutonium were 1.0530 $$pm$$ 0.0008 mg/g (k=2) of uranium with a $$^{235}$$U relative mass fraction of 93.114 wt% and 2.0046 $$pm$$ 0.0019 mg/g (k=2) of plutonium with a $$^{239}$$Pu relative mass fraction of 97.934 wt%, respectively. The concentrations of uranium and plutonium in spike were confirmed by reverse isotope dilution mass spectrometry using tracer of $$^{233}$$U and $$^{242}$$Pu. Finally, the prepared spike was validated by parallel analysis of simulated sample of dissolved MOX solution. This spike was applied to measure the uranium and plutonium amount content of dissolved MOX solutions using isotope dilution mass spectrometry.

JAEA Reports

Report on analytical activities in potentially hazardous materials mitigation measures at the Plutonium Conversion Development Facility; 2015.12 $$sim$$ 2016.10

Horigome, Kazushi; Taguchi, Shigeo; Ishibashi, Atsushi; Inada, Satoshi; Kuno, Takehiko; Surugaya, Naoki

JAEA-Technology 2017-008, 14 Pages, 2017/05

JAEA-Technology-2017-008.pdf:1.15MB

The plutonium solution had been converted into MOX powder to mitigate the potential hazards of storage plutonium solution such as hydrogen generation at the Plutonium Conversion Development Facility. The plutonium conversion operations had been started in April, 2014, and had been finished in July, 2016. With respect to the samples taken from the conversion process, about 2,200 items of plutonium/uranium solutions and MOX powders had been analyzed for the operation control in the related analytical laboratories at the Tokai Reprocessing Plant. This paper describes the reports on analytical activities and related maintenance works in the analytical laboratories conducted from December, 2015 to October, 2016.

JAEA Reports

Determination of metal impurities in MOX powder by direct current arc atomic emission spectroscopy; Application of standard addition method for direct analysis of powder sample

Furuse, Takahiro*; Taguchi, Shigeo; Kuno, Takehiko; Surugaya, Naoki

JAEA-Technology 2016-028, 19 Pages, 2016/12

JAEA-Technology-2016-028.pdf:1.79MB

Metal impurities in MOX powder obtained from uranium and plutonium recovered from reprocessing process of spent nuclear fuel are needed to be determined for its characterization. Direct current arc atomic emission spectroscopy (DCA-AES) is one of the useful methods for direct analysis of powder sample without dissolving the analyte into aqueous solution. However, the selection of standard material, which can overcome concerns such as matrix matching, is quite important to create adequate calibration curves for DCA-AES. In this study, we apply standard addition method using the certified U$$_{3}$$O$$_{8}$$ containing known amounts of metal impurities to avoid the matrix problems. The proposed method provides good results for determination of Fe, Cr and Ni at a significant quantity level contained in MOX samples.

JAEA Reports

Report on analytical activities in potentially hazardous materials mitigation measures at the Plutonium Conversion Development Facility; 2014.4 $$sim$$ 2015.12

Horigome, Kazushi; Suzuki, Hisanori; Suzuki, Yoshimasa; Ishibashi, Atsushi; Taguchi, Shigeo; Inada, Satoshi; Kuno, Takehiko; Surugaya, Naoki

JAEA-Technology 2016-026, 21 Pages, 2016/12

JAEA-Technology-2016-026.pdf:1.14MB

In order to mitigate potential hazards of storage plutonium in solution such as hydrogen generation, conversion of plutonium solution into MOX powder has been carried out since 2014 in the Plutonium Conversion Development Facility. With respect to the samples taken from the conversion process, about 3500 items of plutonium/uranium solutions and MOX powders have been analyzed for the operation control in the related analytical laboratories at the Tokai Reprocessing Plant. This paper describes the reports on analytical activities and related maintenance works in the analytical laboratories conducted from April 2014 to December 2015.

Journal Articles

Study on the behavior of radiolytically produced hydrogen in a high-level liquid waste tank of a reprocessing plant; Comparison between actual and simulated solutions

Kinuhata, Hiroshi*; Yamamoto, Masahiko; Taguchi, Shigeo; Surugaya, Naoki; Sato, Soichi; Kodama, Takashi*; Tamauchi, Yoshikazu*; Shibata, Yuki*; Anzai, Kiyoshi*; Matsuoka, Shingo*

Nuclear Technology, 192(2), p.155 - 159, 2015/11

 Percentile:100(Nuclear Science & Technology)

Experiments using a small-scale apparatus with 30 ml actual high-level liquid waste from the Tokai Reprocessing Plant were carried out to show that the hydrogen concentration in the gas phase reaches a steady-state value of much less than 4% (lower explosive limit) in the absence of sweeping-air. The H$$_{2}$$ concentration reached a steady-state value as was expected and it was compared with a value predicted from an equation with parameters which had been obtained using the simulated solution. Satisfactory agreement showed that the Pd-ion catalytic H$$_{2}$$ consumption reaction previously found in the simulated solution proceeded equally well in the actual solution.

JAEA Reports

Measurement of hydrogen generating from radiolysis of highly active liquid waste and its quantitative evaluation

Yamamoto, Masahiko; Surugaya, Naoki; Mori, Eito; Taguchi, Shigeo; Sato, Soichi

JAEA-Research 2015-013, 27 Pages, 2015/10

JAEA-Research-2015-013.pdf:2.84MB

The H$$_{2}$$ concentration generating from Highly Active Liquid Waste (HALW) of Tokai Reprocessing Plant is measured in a closed experimental system. The experimental results show that H$$_{2}$$ concentration gradually increases at first and then approaches a steady-state due to the H$$_{2}$$ consumption reaction by Pd ions. The highest H$$_{2}$$ concentration is 1200 ppm (0.1%) when the solution temperature is at 23$$^{circ}$$C. It is found that H$$_{2}$$ generating from HALW is equilibrated one order of magnitude lower than the H$$_{2}$$ combustion lower limit. Moreover, a model based on H$$_{2}$$ generation from HALW by the radiolysis and H$$_{2}$$ consumption reaction by Pd ions is proposed and applied to evaluate H$$_{2}$$ concentration behavior in the gas phase. The calculated H$$_{2}$$ concentrations from proposed model agreed well with the experimental values. It is demonstrated that the behavior of H$$_{2}$$ generating from HALW can be evaluated quantitatively by applying the proposed model in this study.

Journal Articles

Evaluation of plutonium(IV) extraction rate between nitric acid and tri-$$n$$-butylphosphate solution using a glass chip microchannel

Yamamoto, Masahiko; Taguchi, Shigeo; Sato, Soichi; Surugaya, Naoki

Journal of Separation Science, 38(10), p.1807 - 1812, 2015/05

 Times Cited Count:7 Percentile:53(Chemistry, Analytical)

The extraction of Pu with tri-$$n$$-butyl phosphate (TBP) is performed using a glass microchip to evaluate the extraction rate. The parallel two-phase laminar flow is constructed in a microchannel by introducing plutonium nitrate solution and TBP diluted with $$n$$-dodecane as aqueous and organic phase, respectively. It was found that extraction ratio of Pu increases with increasing the contact time of two phases. A numerical model based on the diffusion in the microchannel and the reaction at the interface was incorporated to evaluate the extraction rate. The experimental data points were subjected to least-squares fitting and the forward extraction rate of Pu(IV) was determined.

Journal Articles

The Cause of corrosion occurred in a glove box filter casing and its repair technique

Mori, Eito; Yamamoto, Masahiko; Taguchi, Shigeo; Sato, Soichi; Kitao, Takahiko; Surugaya, Naoki

Nippon Hozen Gakkai Dai-11-Kai Gakujutsu Koenkai Yoshishu, p.132 - 138, 2014/07

The contamination of the radioactive material was observed on the filter casing surface of the glove box installed at the analytical laboratory in Tokai Reprocessing Plant. The cause of the contamination was investigated with visual inspection, penetrant testing and ultrasonic thickness measurement. It was found that a micro through-hole due to the corrosion of stainless-steel was generated in the glove box filter casing. The repair work of the filter casing was performed keeping the glove box negative pressure. The corrosion part of filter casing was replaced and newly fabricated casing was connected to the glove box with Tungsten Inert Gas welding method.

Journal Articles

Determination of neptunium in a reprocessing plant by an on-line solid-phase extraction/electrochemical detection system

Taguchi, Shigeo; Yamamoto, Masahiko; Surugaya, Naoki

Journal of Radioanalytical and Nuclear Chemistry, 299(3), p.1539 - 1545, 2014/03

 Times Cited Count:1 Percentile:85.45(Chemistry, Analytical)

A flow-based electrochemical detection system coupled to a solid-phase extraction column was developed for the determination of neptunium. A Np(V) was oxidized completely to Np(VI) by electrolysis using a column electrode composed of carbon fibers. The effluent was loaded onto a TEVA column, and then onto UTEVA column with 3 mol L$$^{-1}$$ HNO$$_{3}$$. The Np(VI) was eluted with 0.01 mol L$$^{-1}$$ HNO$$_{3}$$, and then introduced directly into a flow-through electrolysis cell. An electrochemical detection with a working potential of +0.1 V (vs. Ag/AgCl) was used to detect Np(VI). The current produced on reduction of Np(VI) was monitored continuously, and the Np(VI) concentration was calculated from the peak area. The relative standard deviation of ten analyses was 2.4 % for a Np(VI) solution (0.50 mg L$$^{-1}$$) containing 1.0 g of Np. The detection limit calculated from three-times the standard deviation was 35 $$mu$$g L$$^{-1}$$ (70 ng Np).

Journal Articles

Determination of trace amounts of plutonium in low-active liquid wastes from spent nuclear-fuel reprocessing plants by flow injection-based solid-phase extraction/electrochemical detection system

Taguchi, Shigeo; Yamamoto, Masahiko; Surugaya, Naoki; Kurosawa, Akira; Hiyama, Toshiaki; Tanaka, Tatsuhiko*

Journal of Radioanalytical and Nuclear Chemistry, 288(2), p.435 - 441, 2011/01

 Times Cited Count:2 Percentile:75.97(Chemistry, Analytical)

Journal Articles

Determination of trace amounts of uranium by stripping voltammetry using a boron-doped diamond electrode

Taguchi, Shigeo; Surugaya, Naoki; Kurosawa, Akira; Hiyama, Toshiaki; Tanaka, Tatsuhiko*

Bunseki Kagaku, 59(11), p.1035 - 1041, 2010/11

 Percentile:100(Chemistry, Analytical)

no abstracts in English

Journal Articles

Rapid determination of trace uranium in liquid wastes from spent nuclear-fuel reprocessing plants using on-line solid-phase extraction / electrochemical detection

Taguchi, Shigeo; Surugaya, Naoki; Kurosawa, Akira; Hiyama, Toshiaki; Tanaka, Tatsuhiko*

Bunseki Kagaku, 58(10), p.901 - 907, 2009/10

 Percentile:100(Chemistry, Analytical)

An on-line analysis system using a solid-phase extraction column coupled to electrochemical detection has been developed for rapid determination of small amounts of uranium in liquid wastes of spent nuclear-fuel reprocessing plants. A sample solution with a concentration of 3 M HNO$$_{3}$$ was loaded onto the column: packed with U/TEVA$$^{textregistered}$$ resin. The interference elements were rinsed by passing 3 M HNO$$_{3}$$ through the column. The adsorbed uranium was eluted with 0.1 M HNO$$_{3}$$. The eluate was directly introduced into a flow-electrolysis cell. The result of five repeated analyses for a standard solution containing 2.5 $$mu$$g (0.1 mL at 25 $$mu$$g mL$$^{-1}$$) of uranium was found to be 2.5 $$pm$$ 0.025 $$mu$$g (mean $$pm$$ 1 $$sigma$$). The detection limit calculated from 3 times the standard deviation of background current was 56 ng. The analysis time required for one sample was within 5 min. The recoveries of uranium in actual nuclear waste reprocessing solutions were 92% $$sim$$ 112%.

Journal Articles

Determination of trace amount of uranium by mercury free stripping voltammetry

Taguchi, Shigeo

Bunseki, 2009(9), P. 522, 2009/09

no abstracts in English

60 (Records 1-20 displayed on this page)