Annual report on the environmental radiation monitoring around the Tokai Reprocessing Plant FY2022

Kokubun, Yuji; Nakada, Akira; Seya, Natsumi; Koike, Yuko; Nemoto, Masashi; Tobita, Keiji; Yamada, Ryohei*; Uchiyama, Rei; Yamashita, Daichi; Nagai, Shinji; et al.

JAEA-Review 2023-046, 164 Pages, 2024/03

JAEA-Review-2023-046.pdf:4.2MB

The Nuclear Fuel Cycle Engineering Laboratories conducts environmental radiation monitoring around the reprocessing plant in accordance with the "Safety Regulations for Reprocessing Plant of JAEA, Part IV: Environmental Monitoring". This report summarizes the results of environmental radiation monitoring conducted during the period from April 2022 to March 2023 and the results of dose calculations for the surrounding public due to the release of radioactive materials into the atmosphere and ocean. In the results of the above environmental radiation monitoring, many items were affected by radioactive materials emitted from the accident at the Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company, Incorporated (changed to Tokyo Electric Power Company Holdings, Inc. on April 1, 2016), which occurred in March 2011. Also included as appendices are an overview of the environmental monitoring plan, an overview of measurement methods, measurement results and their changes over time, meteorological statistics results, radioactive waste release status, and an evaluation of the data which deviated of the normal range.

Annual report on the environmental radiation monitoring around the Tokai Reprocessing Plant FY2021

Nakada, Akira; Kanai, Katsuta; Seya, Natsumi; Nishimura, Shusaku; Futagawa, Kazuo; Nemoto, Masashi; Tobita, Keiji; Yamada, Ryohei*; Uchiyama, Rei; Yamashita, Daichi; et al.

JAEA-Review 2022-078, 164 Pages, 2023/03

JAEA-Review-2022-078.pdf:2.64MB

Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2021 to March 2022. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co., Inc. (the trade name was changed to Tokyo Electric Power Company Holdings, Inc. on April 1, 2016) in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and exceeded the normal range of fluctuation in the monitoring, were evaluated.

Annual report on the environmental radiation monitoring around the Tokai Reprocessing Plant FY2020

Nakada, Akira; Nakano, Masanao; Kanai, Katsuta; Seya, Natsumi; Nishimura, Shusaku; Nemoto, Masashi; Tobita, Keiji; Futagawa, Kazuo; Yamada, Ryohei; Uchiyama, Rei; et al.

JAEA-Review 2021-062, 163 Pages, 2022/02

JAEA-Review-2021-062.pdf:2.87MB

Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed by the Nuclear Fuel Cycle Engineering Laboratories, based on "Safety Regulations for the Reprocessing Plant of Japan Atomic Energy Agency, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitant due to the radioactivity discharged from the plant to the atmosphere and the sea during April 2020 to March 2021. In this report, some data include the influence of the accidental release from the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co., Inc. (the trade name was changed to Tokyo Electric Power Company Holdings, Inc. on April 1, 2016) in March 2011. Appendices present comprehensive information, such as monitoring programs, monitoring methods, monitoring results and their trends, meteorological data and discharged radioactive wastes. In addition, the data which were influenced by the accidental release and exceeded the normal range of fluctuation in the monitoring, were evaluated.

Tritium removal of heavy water system and helium system in FUGEN

Takiya, Hiroaki; Kadowaki, Haruhiko; Matsushima, Akira; Matsuo, Hidehiko; Ishiyama, Masahiro; Aratani, Kenta; Tezuka, Masashi

JAEA-Technology 2020-001, 76 Pages, 2020/05

JAEA-Technology-2020-001.pdf:6.06MB

Advanced Thermal Reactor (ATR) FUGEN was operated for about 25 years, and now has been proceeding decommissioning after the approval of the decommissioning plan in Feb. 2008. The reactor, heavy water system and helium system are contaminated by tritium because of neutron absorption of heavy water, which is a moderator. Before dismantling these facilities, it is necessary to remove tritium from them for not only reducing the amount of tritium released to surrounding environment and the risk of internal exposure by tritium but also ensuring the workability. In first phase of decommissioning (Heavy Water and Other system Decontamination Period), tritium decontamination of the reactor, heavy water system and helium system started in 2008 and completed in 2018. This report shows the results of tritium decontamination of the reactor, heavy water system and helium system.

Development of ion beam breeding technology in plants and creation of useful plant resources

Hase, Yoshihiro; Nozawa, Shigeki; Asami, Itsuo*; Tanogashira, Yuki*; Matsuo, Yoichi*; Kanazawa, Akira*; Honda, Kazushige*; Narumi, Issey*

JAEA-Review 2013-059, JAEA Takasaki Annual Report 2012, P. 102, 2014/03

Development of ion beam breeding technology in plants and creation of useful plant resources

Hase, Yoshihiro; Nozawa, Shigeki; Okada, Tomoyuki*; Asami, Itsuo*; Nagatani, Takeshi*; Matsuo, Yoichi*; Kanazawa, Akira*; Honda, Kazushige*; Narumi, Issei

JAEA-Review 2011-043, JAEA Takasaki Annual Report 2010, P. 100, 2012/01

https://jopss.jaea.go.jp/pdfdata/JAEA-Review-2011-043.pdf

Uncertainty assessment of environmental fate of radioactive cesium in the river basins of Fukushima Prefecture through long-term simulation

Nittono, Akira*; Ikenoue, Tsubasa; Shimadera, Hikari*; Matsuo, Tomohito*; Kondo, Akira*

no journal, , 

The Fukushima Daiichi Nuclear Power Plant accident caused extensive Cs contamination. Long-term simulations have been conducted to predict the amount of Cs outflow from river basins to the ocean. However, there are uncertainties about the influences of rainfall, tree types and dams to the Cs outflow. This study focused on how much these three factors influence the Cs outflow in eastern Fukushima river basins from 2011 to 2040. The Cs outflow varied by -10 to +17% depending on precipitation, and by -16 to +19% depending on tree species, decreased by 21% by dams.

Study of removal technique and confirmation technique of removal condition in heavy water withdraw and tritium removal for decommissioning of FUGEN

Kadowaki, Haruhiko; Matsuo, Hidehiko; Yamane, Naoki; Matsushima, Akira

no journal, , 

no abstracts in English

Pulsed high magnetic field measurements in a quasi-degenerate diluted Yb system (Lu,Yb)RhZn

Kitazawa, Takafumi; Ikeda, Yoichi*; Matsuo, Akira*; Imajo, Shusaku*; Shimizu, Yusei*; Kawamata, Masahiro*; Tokunaga, Yo; Haga, Yoshinori; Opletal, P.; Sakai, Hironori; et al.

no journal, , 

A diluted Yb system (Lu,Yb)RhZn is an impurity Kondo alloy with quasi-octet degeneracy due to strong - hybridization. In addition to the large degeneracy of , we found field-induced single-ion magnetic anisotropy above about 5 T, which cannot be explained by the existing Kondo model. To understand the -electron state under magnetic fields, where the magnetic anisotropy develops, we measured the magnetization and specific heat of the diluted Yb system (Lu,Yb)RhZn under pulsed high magnetic fields. The magnetization curves coincided between the processes of increasing and decreasing magnetic fields. This indicates that eddy-current heating is sufficiently suppressed, and isothermal magnetization curves can be measured. The magnetic easy and hard axes along the and directions, respectively, remained unchanged even above the Kondo crossover field of 22.7 T, where the -electrons are localized. The field dependence of the electronic specific heat coefficients, estimated from the specific heat measurements, increased to about 1 J Yb-mol K and decreased around the Kondo crossover field. The decreasing electronic specific heat coefficients at the Kondo field suggest the localization of the -electrons. In addition, the anisotropic magnetic response was observed not only in magnetization but also in specific heat measurements.

Tritium removal test for decommissioning of FUGEN

Matsushima, Akira; Ishiyama, Masahiro; Matsuo, Hidehiko; Sato, Yuji

no journal, , 

no abstracts in English