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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.
Zn
Kitazawa, Takafumi; Ikeda, Yoichi*; Sakakibara, Toshiro*; Matsuo, Akira*; Shimizu, Yusei*; Tokunaga, Yo; Haga, Yoshinori; Kindo, Koichi*; Nambu, Yusuke*; Ikeuchi, Kazuhiko*; et al.
Physical Review B, 108(8), p.085105_1 - 085105_7, 2023/08
Times Cited Count：0 Percentile：0.00(Materials Science, Multidisciplinary)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.
Cu(PO
)SO 
5HO as a model antiferromagnetic spin-1/2 Heisenberg 
- chainFujihara, Masayoshi; Jeschke, H. O.*; Morita, Katsuhiro*; Kuwai, Tomohiko*; Koda, Akihiro*; Okabe, Hirotaka*; Matsuo, Akira*; Kindo, Koichi*; Mitsuda, Setsuo*
Physical Review Materials (Internet), 6(11), p.114408_1 - 114408_8, 2022/11
Times Cited Count：2 Percentile：7.48(Materials Science, Multidisciplinary)
= 1/2 Heisenberg - chain antiferromagnets have been investigated extensively due to their exotic magnetic states. Here, we report the magnetic behavior of birchite CdCu(PO)SO5HO and its effective spin model. Experimental studies by magnetic susceptibility, magnetization, heat capacity, and 
SR measurements indicate the absence of long-range order down to 0.4 K. Theoretical studies reveal that birchite is a model compound for the - antiferromagnetic chain: the intrachain interactions and are antiferromagnetic and their magnitude is about 100 times larger than the interchain interactions. The magnitude of is two to three times larger than that of , thus the spin gap is expected to be only a few percent of that of . The temperature dependence of the specific heat shows a broad peak at about 1 K (
0.036 ), which suggests the presence of a spin gap.
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.
Fujihara, Masayoshi*; Morita, Katsuhiro*; Mole, R.*; Mitsuda, Setsuo*; Toyama, Takami*; Yano, Shinichiro*; Yu, D.*; Sota, Shigetoshi*; Kuwai, Tomohiko*; Koda, Akihiro*; et al.
Nature Communications (Internet), 11, p.3429_1 - 3429_7, 2020/07
Times Cited Count：47 Percentile：92.12(Multidisciplinary Sciences)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.
axisPosp
il, J.*; Haga, Yoshinori; Kohama, Yoshimitsu*; Miyake, Atsushi*; Kambe, Shinsaku; Tateiwa, Naoyuki; Valika, M.*; Proschek, P.*; Prokleka, J.*; Sechovsk
, V.*; et al.
Physical Review B, 98(1), p.014430_1 - 014430_7, 2018/07
Times Cited Count：16 Percentile：58.15(Materials Science, Multidisciplinary)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
Hase, Yoshihiro; Nozawa, Shigeki; Okada, Tomoyuki*; Asami, Itsuo*; Nagatani, Takeshi*; Matsuo, Yoichi*; Kanazawa, Akira*; Honda, Kazushige*; Narumi, Issei
JAEA-Review 2012-046, JAEA Takasaki Annual Report 2011, P. 95, 2013/01
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
Funaki, Hironori; Tokiwa, Tetsuya; Ishii, Eiichi; Hatsuyama, Yoshihiro*; Matsuo, Shigeaki*; Tsuda, Kazuyasu*; Koizumi, Akira*; Ishikawa, Taiki*; Daijo, Yuichi*; Sugiyama, Kazutoshi*
JAEA-Data/Code 2008-013, 65 Pages, 2008/08
JAEA-Data-Code-2008-013.pdf:6.38MB
We conducted geological investigation of the pilot borehole of the ventilation shaft in Horonobe during October 2007 and March 2008. This report describes the field operations (core description, core photograph, and core sampling) and laboratory measurements (modal analysis and X-ray diffraction analysis), equipments as well as processing procedures, and shows the obtained results. The information obtained from this investigation will be reflected in spring water control plan on shaft excavation and additional plan of drainage treatment facilities.
Miyoshi, Nobuaki; Kadowaki, Haruhiko; Matsuo, Hidehiko; Matsushima, Akira
no journal, ,
no abstracts in English
Kadowaki, Haruhiko; Matsuo, Hidehiko; Yamane, Naoki; Asakura, Yamato*; Matsushima, Akira
no journal, ,
no abstracts in English
Kadowaki, Haruhiko; Matsuo, Hidehiko; Yamane, Naoki; Matsushima, Akira
no journal, ,
no abstracts in English
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.
Matsushima, Akira; Ishiyama, Masahiro; Matsuo, Hidehiko; Sato, Yuji
no journal, ,
no abstracts in English
Kitamura, Koichi; Sano, Kazuya; Nakamura, Yasuyuki; Matsushima, Akira; Matsuo, Hidehiko; Ishiyama, Masahiro; Haneda, Takahiro; Tezuka, Masashi
no journal, ,
The decommissioning program of proto-type Advanced Thermal Reactor (ATR) FUGEN has started in 2008 as first decommissioning of the commercial-scale water reactor. It consists of four periods, considering the transportation of spent fuels and the radioactive decrease of highly activated materials. It is expected that the whole program of decommissioning will be completed until 2028.Now, the decommissioning is under the first period, spent fuels and heavy water has been carrying out from FUGEN, and a part of the turbine system with relatively low radioactive contamination has been dismantled. FUGEN has a complicated core structure consisting 224 fuel channels with pressure tubes and calandria tank, etc. and used heavy water as moderator, unlike other light water reactor. So, the dismantling technology of the reactor core and the decontamination technology of tritium in heavy water system, etc. have been studying in order to dismantle them safely. In this presentation, the contents of the decommissioning program and its current status, the studying situation of dismantling technology of reactor core using Abrasive Water Jet (AWJ) which is a candidate of cutting technologies, the examination of tritium decontamination in heavy water system, the study for C-14 penetrated into concrete structure will be presented mainly.
Ando, Koji; Kadowaki, Haruhiko; Matsuo, Hidehiko; Yamane, Naoki; Matsushima, Akira
no journal, ,
no abstracts in English
HOFujihara, Masayoshi; Hagihara, Masato; Okabe, Hirotaka*; Nakamura, Jumpei*; Koda, Akihiro*; Matsuo, Akira*; Kindo, Koichi*; Munakata, Koji*; Ishikado, Motoyuki*
no journal, ,
no abstracts in English
ZnKitazawa, 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.
