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JAEA Reports

Data comparison of measurement of carbon isotope standards between JAEA-AMS-TONO and JAEA-AMS-MUTSU

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.

Journal Articles

Penetration of $$^{129}$$I released from Fukushima Daiichi Nuclear Power Plant accident in the western North Pacific Ocean

Suzuki, Takashi; Otosaka, Shigeyoshi; Kuwabara, Jun; Kawamura, Hideyuki; Kobayashi, Takuya

JAEA-Conf 2018-002, p.103 - 106, 2019/02

To investigate the dynamics of radionuclides in the ocean released by the accident at Fukushima Daiichi Nuclear Power Plant (1F), vertical distributions of $$^{129}$$ I at three stations in the western North Pacific was revealed. The 1F accident-derived $$^{129}$$ I existed within the mixed layer at 3 stations. The maximum layer of the 1F accident-derived $$^{129}$$ I existed at the depth of 370 m - 470 m at the most southern station. Considering the dissolved oxygen concentration and the current velocity arround the station, the maximum layer of the 1F accident-derived $$^{129}$$ I would be fromed that $$^{129}$$I which existed in the surface seawater at other area of observation point was carried to the depth of 370 m - 470 m by the fast downward flow.

Journal Articles

Distribution and fate of $$^{129}$$I in the seabed sediment off Fukushima

Otosaka, Shigeyoshi; Sato, Yuhi*; Suzuki, Takashi; Kuwabara, Jun; Nakanishi, Takahiro

Journal of Environmental Radioactivity, 192, p.208 - 218, 2018/12

AA2017-0744.pdf:1.17MB

 Times Cited Count:10 Percentile:46.51(Environmental Sciences)

From August 2011 to October 2013, the concentration of iodine-129 ($$^{129}$$I) in the seabed sediment collected from 26 stations located within 160 km from the Fukushima Daiichi Nuclear Power Plant was estimated. The concentrations of $$^{129}$$I in seabed sediment off Fukushima in 2011 ranged between 0.02 and 0.45 mBq/kg. Although iodine is a biophilic element, the accident-derived radioiodine negligibly affects the benthic ecosystem. Until October 2013, a slightly increased activity of $$^{129}$$I in the surface sediment in the shelf-edge region (bottom depth: 200-400 m) was observed. The increase of the $$^{129}$$I concentrations in the shelf-edge sediments was affected by the (1) transport of $$^{129}$$I-bound particles from the land through rivers and (2) re-deposition of $$^{129}$$I desorbed from the contaminated coastal sediment to the shelf-edge sediments, which were considered to be dominant processes.

Journal Articles

Vertical distribution of $$^{129}$$I released from the Fukushima Daiichi Nuclear Power Plant in the Kuroshio and Oyashio current areas

Suzuki, Takashi; Otosaka, Shigeyoshi; Kuwabara, Jun; Kawamura, Hideyuki; Kobayashi, Takuya

Marine Chemistry, 204, p.163 - 171, 2018/08

 Times Cited Count:1 Percentile:7.66(Chemistry, Multidisciplinary)

To investigate the penetration of radionuclides released from Fukushima Daiichi Nuclear Power Plant (FDNPP), depth profiles were revealed at Kuroshio current, transition, and Oyashio current areas. The FDNPP-derived $$^{129}$$I was found in surface layer at Oyashio current and transition areas and in sub-surface layer at Kuroshio current area. Moreover, it was found that the FDNPP-derived $$^{129}$$I/$$^{134}$$Cs ratios in the Oyashio current and transition areas were higher than that in the FDNPP reactor. The higher FDNPP-derived $$^{129}$$I/$$^{134}$$Cs ratios suggest three potential mechanisms for the migration of radionuclides in the environment: (1) radioiodine was released more easily than radiocesium by the FDNPP accident, (2) $$^{129}$$I was supplied from the atmosphere by re-emitted $$^{129}$$I from contaminated areas around Fukushima, (3) leaked water that removed radiocesium reached the sampling stations. The FDNPP-derived $$^{129}$$I in sub-surface layer would be transported by the meander of the Kuroshio Extension current.

JAEA Reports

Nuclear Facilities Management Section Mutsu Office, Aomori Research and Development Center operations report; FY 2014&2015

Kuwabara, Jun; Oyokawa, Atsushi; Aoyama, Masaki

JAEA-Review 2017-039, 73 Pages, 2018/03

JAEA-Review-2017-039.pdf:5.16MB

Nuclear Facilities Management Section implemented the operation, maintenance and decommissioning of the first nuclear ship "MUTSU" and the operation and maintenance of the liquid waste facility and the solid waste facility where a small amount of nuclear fuel is used. The Nuclear Facilities Management Section became the Nuclear Facilities and General Facilities Management Section by organization unification in FY 2016. This is the report on the operations of the Nuclear Facilities Management Section for FY 2014 and FY 2015.

JAEA Reports

Decommissioning activities and R&D of nuclear facilities in the second midterm plan

Terunuma, Akihiro; Mimura, Ryuji; Nagashima, Hisao; Aoyagi, Yoshitaka; Hirokawa, Katsunori*; Uta, Masato; Ishimori, Yuu; Kuwabara, Jun; Okamoto, Hisato; Kimura, Yasuhisa; et al.

JAEA-Review 2016-008, 98 Pages, 2016/07

JAEA-Review-2016-008.pdf:11.73MB

Japan Atomic Energy Agency formulated the plan to achieve the medium-term target in the period of April 2010 to March 2015(hereinafter referred to as "the second medium-term plan"). JAEA determined the plan for the business operations of each year (hereinafter referred to as "the year plan"). This report is that the Sector of Decommissioning and Radioactive Waste Management has summarized the results of the decommissioning technology development and decommissioning of nuclear facilities which were carried out in the second medium-term plan.

JAEA Reports

Nuclear Facilities Management Section Mutsu Office, Aomori Research and Development Center operations report; FY 2012&2013

Tajima, Yoshihiro; Kuwabara, Jun; Oyokawa, Atsushi; Kabuto, Shoji; Araya, Naoyuki; Kikuchi, Kaoru; Miyamoto, Shingo; Nemoto, Hideyuki; Oe, Osamu

JAEA-Review 2016-003, 56 Pages, 2016/05

JAEA-Review-2016-003.pdf:7.16MB

Nuclear Facilities Management Section implements the operation, maintenance and decommissioning of the first nuclear ship "MUTSU" and the operation and maintenance of the liquid waste facility and the solid waste facility where a small amount of nuclear fuel is used. This is the report on the operations of the Nuclear Facilities Management Section for FY 2012 and FY 2013.

Journal Articles

Status of JAEA-AMS-MUTSU

Kuwabara, Jun; Kinoshita, Naoki; Tobinai, Kazuhito; Matsuno, Satoru; Oyokawa, Atsushi; Seki, Takeo; Yabuuchi, Noriaki

Dai-28-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.77 - 79, 2015/12

A Tandetron AMS system (JAEA-AMS-MUTSU) at Mutsu Office, Aomori Research and Development Center, Sector of Decommissioning and Radioactive Waste Management, JAEA, installed in 1997, has composed of 3 MV tandem accelerator and two beam lines (carbon and iodine). Status of the JAEA-AMS-MUTSU and trouble of ion source caused by deterioration of optical fiber cable are reported.

Journal Articles

Status of JAEA-AMS-MUTSU

Kuwabara, Jun; Kinoshita, Naoki; Hamada, Akio; Tobinai, Kazuhito; Seki, Takeo

Dai-27-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.27 - 30, 2015/03

A Tandetron AMS system (JAEA-AMS-MUTSU) at Mutsu Office, Aomori Research and Development Center, Sector of Decommissioning and Radioactive Waste Management, JAEA, installed in 1997, has composed of 3 MV tandem accelerator and two beam lines (carbon and iodine). Status of the JAEA-AMS-MUTSU and trouble cases about ion source are reported.

Journal Articles

Iodine-129 concentration in seawater near Fukushima before and after the accident at the Fukushima Daiichi Nuclear Power Plant

Suzuki, Takashi; Otosaka, Shigeyoshi; Kuwabara, Jun; Kawamura, Hideyuki; Kobayashi, Takuya

Biogeosciences, 10(6), p.3839 - 3847, 2013/06

 Times Cited Count:20 Percentile:56.89(Ecology)

no abstracts in English

Journal Articles

Distribution of iodine-129 in the northwestern North Pacific Ocean between Jan and Feb 2012

Suzuki, Takashi; Otosaka, Shigeyoshi; Kuwabara, Jun

Dai-15-Kai AMS Shimpojiumu Hokokushu, p.49 - 52, 2013/03

no abstracts in English

Journal Articles

Status of JAEA-AMS-MUTSU at 2010-2011

Kabuto, Shoji; Kinoshita, Naoki; Tanaka, Takayuki; Kuwabara, Jun; Seki, Takeo

Dai-24-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.9 - 12, 2011/07

A Tandetron Accelerator Mass Spectrometer (AMS) manufactured by High Voltage Engineering Europa in Netherlands had been set up at the Mutsu office of Aomori Research and Development Center, Japan Atomic Energy Agency (JAEA) in 1997. This AMS features 3 MV Tandetron accelerator and two independence beamlines for $$^{14}$$C and $$^{129}$$I measurement. In this report, we describe the summary of the current status at 2010-2011.

Journal Articles

Status of JAEA-AMS-MUTSU

Tanaka, Takayuki; Kabuto, Shoji; Kinoshita, Naoki; Suzuki, Takashi; Kuwabara, Jun; Seki, Takeo

Dai-13-Kai AMS Shimpojiumu Hokokusho, p.129 - 132, 2011/01

An accelerator mass spectrometry at Aomori Research and Development Center, JAEA (JAEA-AMS-MUTSU) was established in 1997 and the routine operation of $$^{14}$$C and $$^{129}$$I measurement was started from 1999 and 2003, respectively. This AMS has adopted the open door policy for the general users from the fiscal year of 2006 and various researches have been in progress by many users. In this presentation, we introduce the status of JAEA-AMS-MUTSU. The total number of measurements has increased well for five years after the open door policy excluding in 2008. The reasons for the decrease in 2008 were that we had stopped the operation of AMS for about one and half months because the operation system of AMS was upgraded, and that we could not measure the $$^{14}$$C for several months because the amplifier of detector had broken. We had resolved this trouble and our AMS can measure smoothly both $$^{14}$$C and $$^{129}$$I.

Journal Articles

Status of JAEA-AMS-MUTSU at 2009-2010

Tanaka, Takayuki; Kabuto, Shoji; Kinoshita, Naoki; Suzuki, Takashi; Kuwabara, Jun; Seki, Takeo

Dai-23-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.113 - 116, 2010/11

An accelerator mass spectrometry at Aomori Research and Development Center, JAEA (JAEA-AMS-MUTSU) was established in 1997 and the routine operation of $$^{14}$$C and $$^{129}$$I measurement was started from 1999 and 2003, respectively. This AMS has adopted the open door policy for the general users from the fiscal year of 2006 and various researches have been in progress by many users. In this presentation, we introduce the status of JAEA-AMS-MUTSU in the fiscal year of 2009. The $$^{14}$$C and $$^{129}$$I were measured by 480 and 677 samples in the fiscal year of 2009, respectively. The total number of measurements has decreased by 716 samples from that of the fiscal year of 2008. The reasons for this decrease were that we had stopped the operation of AMS for about one and half months because the operation system of AMS was upgraded, and that we could not measure the $$^{14}$$C for several months because the amplifier of detector had broken. We had resolved this trouble and our AMS can measure smoothly both $$^{14}$$C and $$^{129}$$I.

Journal Articles

Development of the digestion method of environmental samples by the silver-mediated electrochemical oxidation process for iodine analysis

Kuwabara, Jun

Dai-12-Kai AMS Shimpojiumu Hokokushu, p.112 - 115, 2010/05

In the analysis of the iodine isotope, dry combustion method is used for sample preparation. Depending on the kind of the sample, the iodine remaining situation occurs without volatilizing enough. The silver mediated electrochemical oxidation process was tried to obtain high recovery. Digestion of dried Konbu sample was completed in around 24 hours under 5 V of electric condition. After the digestion, AgI precipitate was obtained by adding sodium sulfite as reductant to the filtered sample solution.

Journal Articles

Wet-digestion of environmental sample using silver-mediated electrochemical method

Kuwabara, Jun

JAEA-Conf 2010-001, p.118 - 121, 2010/03

In pretreatment of environmental samples such as food for measurement of I-129, dry ashing method with electric furnace is often used. On the dry ashing method, suspicious case to certify the homogeneity of iodine from both sample and carrier may occur due to low iodine recovery depending on the sample type. In this study, wet ashing with silver-mediated electrochemical method was applied to pretreatment of environmental sample analysis. Dried Laminariaceae (Konbu) sample was tried to digest using electrolysis device with nitric acid and silver nitrate. At the condition of 1g sample, $$<$$10V and $$<$$2A, fibrous suspended matter disappeared in about 24 hours.

Journal Articles

Development of simple preparation method of seaweed samples for I-129 measurement by AMS

Kuwabara, Jun; Suzuki, Takashi; Amano, Hikaru

KEK Proceedings 2007-16, p.184 - 186, 2008/02

no abstracts in English

Journal Articles

Status and progress of JAEA-MUTSU Tandetron AMS

Amano, Hikaru; Kabuto, Shoji; Kinoshita, Naoki; Suzuki, Takashi; Tanaka, Takayuki; Otosaka, Shigeyoshi; Kuwabara, Jun; Kitada, Yoshinobu*; Watanabe, Yukiya*; Kitamura, Toshikatsu

Dai-19-Kai Tandemu Kasokuki Oyobi Sono Shuhen Gijutsu No Kenkyukai Hokokushu, p.1 - 4, 2007/01

no abstracts in English

Journal Articles

Successful BNCT for patients with cutaneous and mucosal melanomas; Report of 4 cases

Morita, Norimasa*; Hiratsuka, Junichi*; Kuwabara, Chiaki*; Aihara, Teruhito*; Ono, Koji*; Fukuda, Hiroshi*; Kumada, Hiroaki; Harada, Tamotsu*; Imajo, Yoshinari*

Proceedings of 12th International Congress on Neutron Capture Therapy (ICNCT-12), p.18 - 20, 2006/12

Since 2003, group of Kawasaki Medical School has conducted BNCT clinical trials on melanomas at the Kyoto University Research Reactor (KUR) and Japan Research Reactor No.4 (JRR-4). We report 4 patients given BNCT for malignant melanomas, 2 with superficial spreading types on the heel, 1 with mucosal melanoma in the nasal cavity, and 1with a melanoma on the vulva and in the vagina. Although 2 patients experienced normal-tissue damage that exceeded the tolerance level, all the participants were cured within a few months of treatment. BNCT was shown to be a promising treatment for mucosal, as well as for cutaneous, melanomas.

Journal Articles

Uranium analysis in spinach aqueous solution

Watanabe, Yoko; Kuwabara, Jun; Yamaguchi, Noriko*

KEK Proceedings 2006-5, p.19 - 22, 2006/11

no abstracts in English

48 (Records 1-20 displayed on this page)