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Kokubu, Yoko; Matsubara, Akihiro; Fujita, Natsuko; Kuwabara, Jun; Kinoshita, Naoki
JAEA-Technology 2021-028, 33 Pages, 2022/02
JAEA-Technology-2021-028.pdf:2.18MB
Japan Atomic Energy Agency (JAEA) has two facilities of accelerator mass spectrometry, JAEA-AMS-TONO and JAEA-AMS-MUTSU at Tono Geoscience Center and Aomori Research and Development Center, respectively. In this report, characteristics of each facility and results of standard samples in the inner-comparison test of carbon isotope measurement will be described. Both facilities have been used for research by not only JAEA's staff but also researchers who belong to universities and other institutes on the shared use program of JAEA facilities. Recently, researchers trend to use both facilities with the expansion of demand for the carbon isotope measurement by using the accelerator mass spectrometer (AMS). However, each facility has a spectrometer made by a different manufacturer and equipped with different mechanical components. There is a difference in each ability to the carbon isotope measurement such as background level. This is, for example, due to different ion injection system adapted at each spectrometer. Further, each facility uses a different analytical method adjusted to each main research field. When a researcher uses both facilities, the researcher understands more about the characteristics and need to make a suitable choice of a facility for samples and the analytical method. The report presents a detailed information of characteristics of the spectrometer, sample preparation method and analytical method, and of ability of the measurement based on the inner-comparison test.
C from irradiated graphite materials, 1; Oxidation behaviors and the changes in pore structure of Q1 and IG-110 graphite due to the air reaction (Joint research)Fujii, Kimio
JAERI-Tech 2005-048, 108 Pages, 2005/09
JAERI-Tech-2005-048.pdf:25.05MB
The graphite-moderated power reactor was shut down in 1998 and its decommissioning program is being planned. Various graphites are used in the core of magnox-type reactors and HTTR as core-support structural materials and moderating materials of fast neutrons. For the nuclear graphite disposal, it is necessary to determine especially the treatment of long-lived nuclides, such as C which are generated in the graphite components during reactor operation. As a research, which solves the problem of the C concentration, the cooperative research is concluded between JAERI and Japan Nuclear Power Corp. in 1999, and the research for the basic data acquisition has been advanced up to the present. To find the optimum conditions for C reduction, basic data on oxidation reaction and the structure of graphite materials are indispensable. In the present experiment, we measure the air oxidation characteristics in the temperature range 450
800
C in Quality1 graphite and IG-110 graphite. Changes in pore diameter and pore size distribution due to air oxidation are discussed.
Fujii, Kimio; Matsuo, Hideto*
JAERI-Review 2002-034, 44 Pages, 2002/12
JAERI-Review-2002-034.pdf:3.34MB
Graphite material is used as a moderator and reflector of graphite-moderated gas-cooled reactors such as the Tokai Nuclear Power Station of Japan Atomic Power Company. For the decommissioning of those reactors, it is very important to obtain the density of carbon-14 in the graphite of which half-time is very long, and the development of the reduction technique for density of carbon-14 is one of the main technical issues as well. The reactor ceased the commercial operation on March 1998, and is in the process of the decommissioning. Technical developement on nuclear graphite disposal is one of the main issues, and it is pointed out that carbon-14 density is an impotant factor for the treatment on the disposal of the nuclear graphite. In order to resolve the problem, literatures survey was carried out for describing the status of technical development on resolving the problem. This report describes the outline of the literatures surveyed and the list of the related literatures is attached as well.
Mizushima, Toshihiko; Togawa, Orihiko; Mizutani, Yoshihiko*; Kabuto, Shoji*; Yamamoto, Tadatoshi
JAERI-Tech 2000-004, p.68 - 0, 2000/02
JAERI-Tech-2000-004.pdf:7.24MB
no abstracts in English
Mineo, Hideaki; ; *; Uchiyama, Gunzo; Fujine, Sachio
Proc. of 7th Int. Conf. on Radioactive Waste Mamagement and Environmental Remediation (ICEM '99)(CD-ROM), 3 Pages, 1999/00
no abstracts in English
C in tuffaceous soilNagao, Seiya;
Materials Research Society Symposium Proceedings, Vol.353, 0, p.1093 - 1100, 1995/00
no abstracts in English
C species in gaseous wasteEndo, Akira; *; ; ;
Health Physics, 62(4), p.319 - 327, 1992/04
Times Cited Count：3 Percentile：35.31(Environmental Sciences)no abstracts in English
; ;
Journal of Nuclear Science and Technology, 10(2), p.89 - 94, 1973/02
no abstracts in English
C discharged from the Rokkasho reprocessing plant to rice plantsOta, Masakazu; Nagai, Haruyasu; Katata, Genki; Terada, Hiroaki
no journal, ,
no abstracts in English
Kokubu, Yoko; Matsubara, Akihiro; Fujita, Natsuko; Watanabe, Takahiro; Umeda, Koji; Miyake, Masayasu*; Nishizawa, Akimitsu*; Owaki, Yoshio*; Nishio, Tomohiro*; Sanada, Katsuki*; et al.
no journal, ,
The JAEA-AMS-TONO facility at the Tono Geosciences Center, Japan Atomic Energy Agency has an AMS system. Since November 2014, the Toki Research Institute of Isotope Geology and Geochronology has been established at the Center, developing multiple radiometric dating of geological samples and the JAEA-AMS-TONO is the main facility in the institute. The facility has routinely analyzed C and 
Be for investigations into deep underground environments and has performed test measurement of 
Al. In this presentation, we report our present status.
Nagai, Haruyasu; Koarashi, Jun; Atarashi-Andoh, Mariko
no journal, ,
The proposed project aims to understand processes driving carbon cycling in terrestrial ecosystems and their sensitivity to changes in environment, and to predict carbon cycle feedback to climate change. We focus on soil organic carbon (SOC) in the terrestrial ecosystems. There is growing concern that global warming can lead to accelerated microbial decomposition of SOC and enhance the release of CO
from the soil to the atmosphere. Therefore, understanding the response of SOC to global warming is the key to predicting future climate change. Predicting the response of SOC to global warming requires quantitative evaluation of the SOC decomposability. Our approach is the use of C analysis to quantify the decomposability of SOC as a complex of SOC pools characterized by their carbon stocks and specific mean residence times (MRTs). We also introduce a unique methodology using the nuclear test-derived C in the analysis. We aim to expand this study into global scale with the collaboration between FNCA member countries.
