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Yonekawa, Minoru; Iwasaki, Maho; Shimada, Kozue; Yanagiya, Shoko; Tsukada, Manabu; Iizuka, Yoshiyuki; Kaneko, Munenori; Unno, Toshimichi
JAEA-Testing 2015-002, 151 Pages, 2016/03
JAEA-Testing-2015-002.pdf:4.29MB
JAEA-Testing-2015-002-appendix(CD-ROM).zip:5.7MB
Preparatory Office for Hot Laboratory Operation Management in Fukushima Research Infrastructural Creation Center has advanced research and development for decommissioning of TEPCO'S Fukushima Daiichi Nuclear Power Station. For this purpose, work procedure manual of chemical analysis for safety evaluation on processing, disposal and management of radioactive waste such as low dose level rubbles and fuel debris has been prepared. The manual will be used for personnel training and animation function of PowerPoint was used as the beginner of the chemical analysis to understand easily. This report describes about nuclides which were established analysis method and completed to make animation of work procedure.
Sato, Isamu; Onishi, Takashi; Tanaka, Kosuke; Iwasaki, Maho; Koyama, Shinichi
Journal of Nuclear Materials, 461, p.22 - 28, 2015/06
We observed one of the simplified processes by conducting primitive experiments. CsI was heated at 1323 K to be vaporized and deposited on sampling parts with a temperature range of 1023 - 423 K and then B
O
was vaporized at 1973 K to be reacted with Cs/I there. After heating tests, each sampling part was soaked into alkali water to dissolve the surface-deposits for ICP-MS analysis. The results showed that CsI deposited at the sampling parts kept above approx. 850 K was striped by BO vapour. This behaviour will be thermodynamically discussed to study the Cs/I/B chemistry in the severe accidents.
Sato, Isamu; Onishi, Takashi; Tanaka, Kosuke; Iwasaki, Maho; Koyama, Shinichi
Journal of Nuclear Materials, 461, p.22 - 28, 2015/06
Times Cited Count：8 Percentile：56.13(Materials Science, Multidisciplinary)In order to evaluate B influence on the release and transport of Cs and I during severe accidents, basic experiments have been performed on the interaction between deposited Cs/I compounds and vapor/aerosol B compounds. CsI and BO were utilized as a Cs/I compound and a B compound, respectively. Deposited CsI on the thermal gradient tube (TGT), which is exposed to temperatures ranging from 423 K to 1023 K was reacted with vapor/aerosol BO, and then observed to determine how it changed Cs/I decomposition profiles. As a result, vapor/aerosol BO stripped a portion of deposited CsI within a temperature range from 830 K to 920 K to make gaseous CsBO and I. In addition, gaseous I was re-deposited at a temperature range from 530 K to 740 K, while CsBO travelled through the sampling tubes and filters without deposition. It is implied that B influences Cs carriers such as CsBO to transport Cs to the colder regions.
Sato, Isamu; Miwa, Shuhei; Tanaka, Kosuke; Nakajima, Kunihisa; Hirosawa, Takashi; Iwasaki, Maho; Onishi, Takashi; Osaka, Masahiko; Takai, Toshihide; Amaya, Masaki; et al.
Proceedings of 2014 Water Reactor Fuel Performance Meeting/ Top Fuel / LWR Fuel Performance Meeting (WRFPM 2014) (USB Flash Drive), 6 Pages, 2014/09
A new research program on severe accidents is lunched for the evaluation of FP release and transport behavior in BWR system. The purpose of the program is to improve the FP release and transport model using experimental database about FP chemistry focusing on Cs and I chemistry. In this program, effects of B including in control rod materials, B
C for the Cs and I chemistry are paid attention. The experimental database used for the improvement will consist of results to obtain with newly-prepared test device under atmosphere with broad-ranging oxygen and/or steam partial pressure simulated those in BWR. The state of preparation for these experimental studies and analyses is introduced. In addition, the preliminary test was moved into action to show B chemical effect on Cs and I transport under one of the processes, which is deposited Cs compounds and B vapor and aerosol interaction. In this experiment, a "B stripping effect" to deposited CsI was observed.
Iwasaki, Maho; Tanaka, Kosuke; Sato, Isamu; Miwa, Shuhei; Osaka, Masahiko; Amaya, Masaki; Koyama, Shinichi; Seki, Takayuki*; Tokoro, Daishiro*; Ishigamori, Toshio*
no journal, ,
no abstracts in English
Shimada, Kozue; Iwasaki, Maho; Kurosawa, Katsuaki; Hamada, Yosei; Yonekawa, Minoru; Sato, Soichi; Kaji, Naoya; Koyama, Tomozo; Nakayama, Shinichi
no journal, ,
Iwasaki, Maho; Sato, Soichi; Kaji, Naoya
no journal, ,
no abstracts in English
Sato, Soichi; Iwasaki, Maho; Miura, Katsue; Furusho, Yoshiaki*; Nakayama, Shinichi
no journal, ,
Do, V. K.; Yamamoto, Masahiko; Taguchi, Shigeo; Kuno, Takehiko; Miura, Katsue; Iwasaki, Maho; Sato, Soichi
no journal, ,
Technical support for environmental restoration of Fukushima and decommissioning of Fukushima Daiichi Nuclear Power Station (1F) are the most important mission of Japan Atomic Energy Agency (JAEA). In this presentation, we outline Okuma Analysis and Research Center and our mission on technical development for analyzing rubble and wastes from the decommissioning of 1F. Novel analytical methods are being developed at the center for determining difficult-to-measure nuclides. In addition, some analytical techniques based on liquid electrode plasma optical emission spectrometry, a novel optically spectroscopic method, for measuring elemental composition of highly active liquid wastes is reported.
Do, V. K.; Horita, Takuma; Miura, Katsue; Iwasaki, Maho
no journal, ,
Radioactive Material Analysis and Research Facility has been recently established to support the analysis of samples including fuel debris and radioactive wastes from the decommissioning of Fukushima Daiichi Nuclear Power Station (1F). ICP-MS is considered as a potential analytical tool for long-lived nuclides in fuel debris because of its superior sensitivity. Moreover, the use of ICP-MS is aimed to increase the analysis capacity, which make possible to repeat measurements in order to obtain precise results and to reduce exposed dose of analysts because ICP-MS is much more rapid than radiometric methods. Employing latest advanced technologies, a triple quadrupole ICP-MS, Agilent 8900 (ICP-QQQ-MS), enables to suppress the isobaric interference. In this presentation, we report some demonstrative separations of difficult-to-measure nuclides using the ICP-QQQ-MS system. The obtained results indicate that the separations are possible with suitable reaction gases.
Iwasaki, Maho; Sato, Soichi
no journal, ,
The Tohoku Earthquake and the tsunami that followed occurred in March 2011. The surge from the tsunami caused loss of cooling system in Tokyo Electric Power Company Holdings Fukushima Daiichi Nuclear Power Station (1F). The loss of cooling system allowed the fuel in reactor units 1-3 at least partially meltdown and caused hydrogen explosions in unites 1 and 3. As the results of the explosions, a large amount of radioactive materials were released into the environment and contaminated a vast area containing the 1F site. Japan Atomic Energy Agency, JAEA, currently sets up an Okuma Analysis and Research Center next to the 1F site, which aims at characterizing radioactive wastes and fuel debris generated in the 1F site. Radioactive waste samples taken in the 1F site are planned to be analysed by mainly conventional radiometric methods. These measurements require complicated and time-consuming process including chemical separation and purification in advance. To avoid the chemical separation, Inductively Coupled Plasma-Quadrupole Mass Spectrometry, ICP-QMS, which has an advantage of sensitivity over radiometric analysis for long-lived radionuclides, was applied. Isobaric interference is the major task to be solved for the mass spectrometric analysis. The procedure of the mass-based analytical method for radionuclides and the detailed results for an example case for Zr-93 are described in this presentation.
Horita, Takuma; Iwasaki, Maho
no journal, ,
no abstracts in English
Iwasaki, Maho; Suzuki, Tatsuya*; Yamamura, Tomoo*; Konashi, Kenji*; Shikamori, Yasuyuki*; Noguchi, Shinichi
no journal, ,
no abstracts in English
