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Aoya, Juri; Miyata, Katsuhiko*; Terakado, Akihito*; Otsuzumi, Yoji*; Kurosawa, Daiki*; Sunaba, Takanobu*; Oyama, Yuto*; Inada, Satoshi
Nihon Hozen Gakkai Dai-17-Kai Gakujutsu Koenkai Yoshishu, p.507 - 512, 2021/07
The high level radioactive liquid waste is analyzed for the vitrification process control and the vitrified waste quality in the hot cell of Tokai Vitrification Facility, Tokai Reprocessing Plant. There are 8 Master-slave manipulators, 7 lighting equipment, an electronic balance, and an inductively coupled plasma-optical emission spectrometer used for remote operation, securing visibility, total oxide analysis, and elemental analysis in the analytical hot cell. These equipment and analytical apparatus must be secured with the integrity all the time because the vitrification process cannot be proceeded without analysis of the high level radioactive liquid waste. We constructed the self-remote-maintenance technologies of these equipment and analytical apparatus which reduce the risks of radioactive contamination, radiation exposure, and injury of an operator and also were optimized with respect to a labor, time, and cost, based on the operation of approximately 20 years.
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.
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.
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
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.
Horigome, Kazushi; Taguchi, Shigeo; Ishibashi, Atsushi; Inada, Satoshi; Kuno, Takehiko; Surugaya, Naoki
JAEA-Technology 2017-008, 14 Pages, 2017/05
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.
Horigome, Kazushi; Suzuki, Hisanori; Suzuki, Yoshimasa; Ishibashi, Atsushi; Taguchi, Shigeo; Inada, Satoshi; Kuno, Takehiko; Surugaya, Naoki
JAEA-Technology 2016-026, 21 Pages, 2016/12
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.
Nishihara, Kenji; Yamagishi, Isao; Yasuda, Kenichiro; Ishimori, Kenichiro; Tanaka, Kiwamu; Kuno, Takehiko; Inada, Satoshi; Goto, Yuichi
Journal of Nuclear Science and Technology, 52(3), p.301 - 307, 2015/03
Times Cited Count:17 Percentile:81.3(Nuclear Science & Technology)After the severe accident at the Fukushima-1 nuclear power plant, large amounts of contaminated stagnant water have accumulated in turbine buildings and their surroundings. This rapid communication reports calculation of the radionuclide inventory in the core, collection of measured inventory in the stagnant water, and estimation of radionuclide release ratios from the core to the stagnant water. This evaluation is based on data obtained before June 3, 2011. The release ratios of tritium, iodine, and cesium were several tens of percent, whereas those of strontium and barium were smaller by one or two orders of magnitude. The release ratios in the Fukushima accident were equivalent to those in the TMI-2 accident.
Nishida, Naoki; Suwa, Toshio; Tanaka, Naoki; Inada, Satoshi; Kuno, Takehiko
Nihon Hozen Gakkai Dai-11-Kai Gakujutsu Koenkai Yoshishu, p.121 - 126, 2014/07
Corroded pore was found at stainless pipe for liquid waste solution from the analytical laboratory. Part of the pipe was cut for preparing samples to investigate the cause of the corrosion. The same size of stainless pipe was welded to recover it, under the strict radiation control. The restoration work was done inside of the vinyl house, as it is called "greenhouse", which was the small room completely separated by vinyl sheet. All the works, cutting, decontamination, digging groove and welding with back seal gas, were done inside of the greenhouse. We report the work method for recovery of corroded pipe containing radioactive materials
Nishihara, Kenji; Yamagishi, Isao; Yasuda, Kenichiro; Ishimori, Kenichiro; Tanaka, Kiwamu; Kuno, Takehiko; Inada, Satoshi; Goto, Yuichi
Nihon Genshiryoku Gakkai Wabun Rombunshi, 11(1), p.13 - 19, 2012/03
After the severe accident in the Fukushima-1 Nuclear Power Plant, large amount of contaminated stagnant water has been produced in turbine buildings and those surroundings. This rapid communication reports calculation of radionuclide inventory in the core, collection of measured inventory in the stagnant water, and estimation of radionuclide release ratios from the core to the stagnant water. The present evaluation is based on data obtained before June 3, 2011.
; ; ; Ikeda, Hisashi ; Jitsukata, Shu*; *
JNC TN8410 2000-022, 55 Pages, 2000/05
Measurement of U and Pu concentrations by wavelength dispersion type X-ray fluorescence spectrometry was studied. Sample holder was installed inside of glove box and other instruments, X-ray tube, monochromator and detectors were set out side of the glove box. X-rays was irradiated to sample though Be window. Fluorescent X-rays form sample were also passing though the same Be window and detected outside. Analytical conditions were optimized as follows. Sample thickness is 8 mm, which is 3ml of sample volume by the sample holder. Voltage and eurrent for X-ray tube is 50kV and 40 mA, respectively. Measurement was done twice, 60 seconds each, and averaged X-ray intensity was used to calculate elemental concentrations. Matrix correction was necessary to measure U and Pu concentration within 10% accuracy. Detection limits were calculated to 0.4 mg/L for U and 0.7mg/L for Pu. Calibration curve was liner up to 9 g/L fbr U and Pu. Two calculation methods, calibration curve method and standard addition method, were studied to measure Pu concentration in organic solution. Detection limit was 5.3 mg/L and 0.2 mg/L, respectively.
; *; Ikeda, Hisashi ; Kaminaga, Kazuhiro; ; ; Kuno, Yusuke
PNC TN8410 96-266, 67 Pages, 1996/05
None
Masui, Kenji; Kitao, Takahiko; Inada, Satoshi; Yamada, Keiji; Watahiki, Masaru
no journal, ,
no abstracts in English
Masui, Kenji; Suzuki, Yasaka*; Kitao, Takahiko; Inada, Satoshi; Yamada, Keiji; Watahiki, Masaru
no journal, ,
no abstracts in English
Ogura, Hiroshi; Inada, Satoshi; Igarashi, Kazuto*; Yamada, Keiji; Watahiki, Masaru
no journal, ,
no abstracts in English
Yamamoto, Masahiko; Taguchi, Shigeo; Do, V. K.; Inada, Satoshi; Kuno, Takehiko
no journal, ,
Microchip is a glass plate that has a microchannel typically below 100 m. Various chemical process can be performed in flow by introducing sample solution through this microchannel. One of the application of microchip is solvent extraction. If microchip can be applied to Pu analysis, it is possible to reduce waste generation, radiation exposure of laboratory staff and simplify the analytical operation. In this study, we have developed an online alpha liquid scintillation measurement system coupled with microchip application to the separation field of analysis pretreatment. Quantitative analysis of plutonium has been performed by using the developed system. In the conference, we present these experimental results.
Do, V. K.; Yamamoto, Masahiko; Taguchi, Shigeo; Inada, Satoshi; Takamura, Yuzuru*; Kuno, Takehiko
no journal, ,
A simple and rapid method for determination of Cs and Tc in highly radioactive liquid waste (HALW) using liquid electrode plasma (LEP) has been developed. Effects of pulsed voltage sequence and nitric acid concentration on emissions of these elements are investigated. The method is applied to the quantitative analysis of Cs and Tc in HALW samples at Tokai reprocessing plant.
Taguchi, Shigeo; Do, V. K.; Yamamoto, Masahiko; Inada, Satoshi; Takamura, Yuzuru*; Kuno, Takehiko
no journal, ,
Optical emission peaks of main FP such as Tc and Cs, and Fe were observed in spectra of simulated highly active liquid waste based on liquid electrode plasma. It was found that this optical emission spectrometry based on liquid electrode plasma could be applied to analysis for reprocessing solution.
Saegusa, Yu; Yamamoto, Masahiko; Nishida, Naoki; Taguchi, Shigeo; Watanabe, Nobuhisa; Inada, Satoshi; Kuno, Takehiko
no journal, ,
Iodine in gaseous radioactive waste at the reprocessing facility is collected on an activated charcoal filter. Iodine129 is measured by radioactive analysis using a Ge semiconductor detector. In this research, the correction method for the influence of self-absorption and iodine recovery is proposed. The influence of self-absorption is evaluated by determining the linear attenuation coefficient of activated charcoal filter. Iodine recovery on the activated charcoal filter is also evaluated by measuring -ray intensity from both side of the filter.
Yamamoto, Masahiko; Do, V. K.; Taguchi, Shigeo; Inada, Satoshi; Takamura, Yuzuru*; Kuno, Takehiko
no journal, ,
In this research, we focused on liquid electrode plasma optical emission spectrometry(LEP-OES), which is effective method to minimize the analytical device, to determine technetium (Tc) in reprocessing solution. Measurement conditions such as applied voltage, output pulse sequence and nitric acid concentration were optimized. Consequently, measurement condition at voltage of 1000V, pulse width of 2ms, pulse interval of 8ms, pulse number of 50 and nitric acid concentration of 0.4M offers the high peak intensity with good reproducibility. Also, interference of coexisting elements in sample from reprocessing steam was investigated for Tc peak at 254.3nm, 261.0nm, 264.7nm. The spectral interference of iron was observed at Tc peak of 254.3nm and 261.0nm although no spectral interference were observed at 264.7nm peak. It was found that determination of Tc by LEP-OES can be possible using this peak.