Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 89

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

JAEA Reports

Physical property investigation of gloves for glove boxes in nuclear fuel reprocessing plants; Physical properties of used gloves and estimation of its life-time

Yamamoto, Masahiko; Nishida, Naoki; Kobayashi, Daisuke; Nemoto, Ryo*; Hayashi, Hiroyuki*; Kitao, Takahiko; Kuno, Takehiko

JAEA-Technology 2023-004, 30 Pages, 2023/06

JAEA-Technology-2023-004.pdf:1.94MB

Glove-box gloves, that are used for handling nuclear fuel materials at the Tokai Reprocessing Plant (TRP) of the Japan Atomic Energy Agency, have an expiration date by internal rules. All gloves are replaced at a maximum of every 4-year. However, degrees of glove deterioration varies depending on its usage environment such as frequency, chemicals, and radiation dose. Therefore, physical properties such as tensile strength, elongation, hardness of gloves are measured and technical evaluation method for the glove life-time is established. It was found that gloves without any defects in its appearance have enough physical properties and satisfies the acceptance criteria values of new gloves. Thus, it was considered that the expired gloves could be used for total of 8-year, by adding 4-year of new glove life-time. In addition, the results of extrapolation by plotting the glove's physical properties versus the used years showed that the physical properties at 8-year is on the safer side than the reported physical properties of broken glove. Also, the data are not significantly different from the physical properties of the long-term storage glove (8 and 23 years). Based on these results, life-time of gloves at TRP is set to be 8-year. The frequency of glove inspections are not changed, and if any defects is found, the glove is promptly replaced. Thus, the risk related to glove usage is not increased. The cost of purchasing gloves, labor for glove replacement, and the amount of generated waste can be reduced by approximately 40%, respectively, resulting in more efficient and rationalized glove management.

Journal Articles

Development of training course on non-destructive assay of nuclear material for Asian region, 2; Development of lectures and exercises on gamma-ray measurement

Yamamoto, Masahiko; Kono, Soma; Saegusa, Yu; Kuno, Takehiko; Sekine, Megumi; Inoue, Naoko; Noro, Naoko; Rodriguez, D.; Yamaguchi, Tomoki; Stinett, J.*

Proceedings of INMM & ESARDA Joint Annual Meeting 2023 (Internet), 10 Pages, 2023/05

The gamma-ray measurement part of the Non-Destructive Assay (NDA) course of safeguards and nuclear material accountancy was developed to focus on gamma-ray measurement allotting two days out of five days. The lectures on the basic characteristics and detection methods and mechanism of gamma-ray detectors were provided as e-learnings which were developed. The part for hands-on exercises were implemented in JAEA facility. Participants have set up each gamma-ray detector, and performed measurements of uranium and the other gamma-ray emitting nuclides. Also, uranium-235 enrichment measurements have been performed. In addition, the participants trained with a handheld gamma-ray spectrometer, HM-5, that is popular for IAEA safeguards as the preparation in the measurement exercise of fresh fuel assemblies in JRR-3, a research reactor facility of JAEA. This paper reports on the development, implementation, and feedback from participants on gamma-ray measurement part of the NDA course.

Journal Articles

Accurate and precise measurement of uranium content in uranium trioxide by gravimetry; Comparison with isotope dilution mass spectrometry and its uncertainty estimation

Yamamoto, Masahiko; Horigome, Kazushi; Kuno, Takehiko

Applied Radiation and Isotopes, 190, p.110460_1 - 110460_7, 2022/12

 Times Cited Count:1 Percentile:33.72(Chemistry, Inorganic & Nuclear)

Gravimetric measurement of U content in UO$$_{3}$$ with ignition in the air has been investigated. The ignition temperature, ignition time and aliquot sample mass are optimized as 900$$^{circ}$$C, 60 minutes, and 1 g, respectively. The method is validated by IDMS with uncertainty estimation. The obtained result by gravimetry is 0.78236$$pm$$0.00051 g/g (k=2) and agreed with IDMS value within its uncertainty. It has been found that U in UO$$_{3}$$ can be measured accurately and precisely by gravimetry.

JAEA Reports

Completion of waste removal work from the hot cell of Operation Testing Laboratory in Tokai Reprocessing Plant

Goto, Yuichi; Suzuki, Yoshimasa; Horigome, Kazushi; Miyamoto, Toshihiko*; Usui, Masato*; Mori, Eito*; Kuno, Takehiko

JAEA-Technology 2022-005, 42 Pages, 2022/07

JAEA-Technology-2022-005.pdf:4.48MB

Radioactive wastes were generated and stored in the hot cell of Operation Testing Laboratory of Tokai Reprocessing Plant due to the experiments related to the reprocessing technology development from 1974 to 2014. Waste removal work was strengthened by the shift work in the past, however another wastes were generated by the equipment dismantling. From 2006, an improved waste removal method was established by using bag-out technique and wastes were taken from the glove-box connected to the hot cell. The removal period, estimated from the conventional method using Cask No. 10, was reduced from 14 to 5 years. From 2016, upgrade of worker's awareness including related departments was performed by various software and hardware improvements. Also, the worker's skills were improved and equipment in Cask No.10 was checked for preventive maintenance. The prevention measures for past troubles were discussed with Radiation Control Department. In addition, transportation schedule including safety operation with Transportation Department and Waste Receiving Department was optimized to maintain the waste removal cycle. The removal period was reduced from 5 to 3 years by the above efforts. Finally, the work was completed in March 2020.

Journal Articles

Development of a local exhaust device for removal of radioactive waste from glove-box for handling nuclear fuel materials

Ishibashi, Atsushi; Saegusa, Yu; Aoya, Juri; Yamamoto, Masahiko; Taguchi, Shigeo; Kuno, Takehiko

Nihon Hozen Gakkai Dai-18-Kai Gakujutsu Koenkai Yoshishu, p.241 - 244, 2022/07

no abstracts in English

Journal Articles

Investigation of physical properties of glove for glove-box and estimation of its life-time

Kobayashi, Daisuke; Yamamoto, Masahiko; Nishida, Naoki; Miyoshi, Ryuta; Nemoto, Ryo*; Hayashi, Hiroyuki*; Kato, Keisuke; Nishino, Saki; Kuno, Takehiko; Kitao, Takahiko; et al.

Nihon Hozen Gakkai Dai-18-Kai Gakujutsu Koenkai Yoshishu, p.237 - 240, 2022/07

All gloves attached to glove-box in Tokai Reprocessing Plant have a fixed expiration date and have to be replaced every 4-year. However, degrees of glove deterioration are different depending on its usage environment (frequency, chemicals, radiation, etc.), because of rubber products. Therefore, physical properties such as tensile strength, elongation, hardness of gloves are measured, and the life-time of gloves are estimated. As a result, gloves without any defects in its appearance have enough physical property for acceptance criteria of new glove. The extrapolated physical property of glove is sufficiently larger than the reported values of damaged glove. No deterioration in physical properties of gloves, that are periodically replaced without any defects in its appearance, is observed and the usable life-time of the glove is estimated to be 8 years.

Journal Articles

Determination of alkali and alkaline earth elements in radioactive waste generated from reprocessing plant by liquid electrode plasma optical emission spectrometry

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

Journal of Radioanalytical and Nuclear Chemistry, 327(1), p.433 - 444, 2021/01

 Times Cited Count:0 Percentile:0.01(Chemistry, Analytical)

A simple, practical, and reliable analytical method for determination of Na, K, Ca, Sr, and Ba by liquid electrode plasma optical emission spectrometry is developed. Appropriate emission lines for quantification, interferences from co-existing elements, and effect of measurement conditions with cell damage have been investigated. The spike and recovery tests using actual sample have been performed for method validation, and negligible sample matrix effect has been observed. Consequently, the method is successfully applied to several radioactive wastes. The obtained data have been agreed well with data from computer calculation and inductively coupled plasma optical emission spectrometry within 10% difference.

JAEA Reports

Automation technique of analytical pre-treatment for radioactive sample measurement using the program written by visual basic for applications

Yamamoto, Masahiko; Karo, Yoshinori*; Kodaka, Noriyasu; Kuno, Takehiko

JAEA-Technology 2019-014, 68 Pages, 2019/10

JAEA-Technology-2019-014.pdf:2.93MB

Analytical devices like syringe pump, electric burette, fraction collector, and electric valve have been controlled by the program written with Visual Basic for Applications (VBA Macro) to automate the column separation of radioactive sample measurement. It is found that VBA Macro can control each device. Therefore, automatic conditioning and separation equipment were made by combining each device and sequentially controlling with the program. The automation conditioning equipment can repeatedly perform conditioning operation with maximum of 8 columns. The automation separation equipment can separate and recover Sr in simulated highly active liquid waste by using Eichrom Technologies Sr resin. It is found that the developed automation method, using commercially available VBA Macro, is effective to reduce labor work, operator's radiation exposure, and to prevent operational error of analysis, together with reducing the cost of automation.

Journal Articles

Development of an online measurement system using an alpha liquid scintillation counter and a glass-based microfluidic solvent extraction device for plutonium analysis

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

Applied Radiation and Isotopes, 152, p.37 - 44, 2019/10

 Times Cited Count:5 Percentile:67.25(Chemistry, Inorganic & Nuclear)

An online measurement system using an alpha liquid scintillation counter ($$alpha$$-LSC) coupled to microchip solvent extraction has been developed. A flow-through cell of $$alpha$$-LSC has been prepared by packing PTFE tube into glass tube to combine microchip. Two-phase flow in microchannel has been stabilized by using coiled tube. The Pu in organic phase has been mixed with scintillation cocktail by T-junction connectors. The system separates and detects Pu by online with detection limit of 6.5 Bq/mL, generating only $$mu$$L-level wastes.

Journal Articles

Treatment technology of highly radioactive solid waste generated by experimental tests and sample analysis in reprocessing facilities

Goto, Yuichi; Inada, Satoshi; Kuno, Takehiko; Mori, Eito*

Nihon Hozen Gakkai Dai-16-Kai Gakujutsu Koenkai Yoshishu, p.221 - 224, 2019/07

Test equipment, containers, and analytical wastes, generated by experiments using spent fuel pieces in hot cell of Operation Testing Laboratory and by analysis of highly active liquid wastes in hot analytical cell line of Tokai Reprocessing Plant, are treated as highly radioactive solid wastes. These wastes are stored in specific shielded containers called waste cask and then transport to the storage facility. The treatment of these highly radioactive solid wastes have been carried out for 40 years with upgrading waste taking out system and transportation device. As a results, automation of several procedures have been achieved utilizing conventional equipment, and work efficiency and safety have been improved.

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

 Times Cited Count:5 Percentile:42.51(Spectroscopy)

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

Proceedings of 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.

Journal Articles

Physical property evaluation of valve seal material at analytical radioactive liquid waste storage tanks in reprocessing facility

Goto, Yuichi; Yamamoto, Masahiko; Kuno, Takehiko; Inada, Satoshi

Nihon Hozen Gakkai Dai-15-Kai Gakujutsu Koenkai Yoshishu, p.489 - 492, 2018/07

Radioactive liquid waste from the Tokai Reprocessing Facility Analytical Laboratory is temporarily stored in intermediate waste storage tank by using receiving valves. Then, the liquid waste is transferred to liquid treatment facility by using liquid feed valves. The deterioration of the gasket part of these valves (leakage of waste liquid) was confirmed in 2004. Since then, the material of gaskets was changed from polyethylene to Teflon. In 2016, the gaskets were replaced by periodical update. Therefore, physical properties of used gaskets were investigated, and the relevance between radioactive level and degradation degree was evaluated.

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:10 Percentile:39.94(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

 Times Cited Count:4 Percentile:15.45(Chemistry, Analytical)

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

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

no abstracts in English

Journal Articles

Design and application of greenhouse on the maintenance of analytical machineries in Tokai Reprocessing Plant

Suzuki, Yoshimasa; Tanaka, Naoki; Goto, Yuichi; Inada, Satoshi; Kuno, Takehiko

Nihon Hozen Gakkai Dai-14-Kai Gakujutsu Koenkai Yoshishu, p.385 - 389, 2017/08

Greenhouse is used in order to prevent diffusion of radioactive materials on the maintenance of machineries and decomposition of the analytical equipment such as glove box in Tokai Reprocessing Plant (TRP). The specifications of the greenhouse change depending on a risk of the radiation exposure, operation and environment. Design and application of original greenhouses in the analytical laboratory of TRP is summarized.

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.

89 (Records 1-20 displayed on this page)