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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.
Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count：43 Percentile：96.93(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 
C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
Seno, Yasuhiro*; Noguchi, Akira*; Nakayama, Masashi; Sugita, Yutaka; Suto, Shunkichi; Tanai, Kenji; Fujita, Tomoo; Sato, Haruo*
JAEA-Technology 2016-011, 20 Pages, 2016/07
JAEA-Technology-2016-011.pdf:7.56MB
Cementitious materials are expected to be used for the construction of an underground repository for the geological disposal of radioactive wastes. Ordinary Portland Cement(OPC) would conventionally be used in the fields of civil engineering and architecture, however, OPC has the potential to generate a highly alkaline plume (pH
12.5), which will likely degrade the performance of other barriers in the repository such as the bentonite buffer and/or host rock. Low alkaline cementitious materials are therefore being developed that will mitigate the generation of a highly alkaline plume. JAEA has developed a High-volume Fly ash Silica fume Cement (HFSC) as a candidate low alkaline cementitious material. The workability of the HFSC shotcrete was confirmed by conducting In-situ full scale construction tests in the Horonobe underground research laboratory. This report summarizes the results of immersion tests to assess the long-term pH behavior of hardened HFSC cement pastes made with mix designs that are expected to be able to be used in the construction of an underground repository in Japan.
Tada, Hiroyuki*; Kumasaka, Hiroo*; Saito, Akira*; Nakaya, Atsushi*; Ishii, Takashi*; Sanada, Masanori; Noguchi, Akira*; Kishi, Hirokazu*; Nakama, Shigeo; Fujita, Tomoo
Dai-13-Kai Iwa No Rikigaku Kokunai Shimpojiumu Koen Rombunshu (CD-ROM), p.133 - 138, 2013/01
The authors have been developing methods for constructing tunnels using the minimum quantities of cement-type support materials in high-level radioactive waste disposal facilities and advancing research and development about the technical formation of rock segment using low alkaline mortar. In this study, the mechanical characteristic values concerning the rock segment and backfill materials were examined. The stability analysis of tunnel supported by the rock segment and backfilling with gravel were performed. Technical formation and effectiveness of the alternative supports planned for further reduction in cement influence was confirmed from a study result above-mentioned.
Noguchi, Akira; Kishi, Hirokazu; Hatanaka, Koichiro; Naito, Morimasa
Proceedings of 19th International Conference on Nuclear Engineering (ICONE-19) (CD-ROM), 6 Pages, 2011/10
A standardized method for choosing a mix design of low pH shotcrete is proposed for their intended use in the construction of a High Level Radioactive Waste (HLW) repository in order to be applied to the various geological environment of the location of the HLW repositories. There are two improvement in this method. One is estimating binder composition to satisfy low pH. The other is estimating water bender ratio to satisfy the strength of sprayed concrete. The method uses a sequential development process with consideration given to a number of physicochemical requirements, incorporates current shotcrete technology. The method is demonstrated in its entirety through a series of experiments and tests using a low pH cement binder comprised of a mixture of ordinary Portland cement, fly ash (FA) and silica fume (SF), referred to here as high-volume FA SF cement (HFSC). Moreover, the method is referred from the demonstration of HFSC shotcrete in Horonobe underground research laboratory.
Nagao, Keisuke*; Okazaki, Ryuji*; Nakamura, Tomoki*; Miura, Yayoi*; Osawa, Takahito; Bajo, Kenichi*; Matsuda, Shintaro*; Ebihara, Mitsuru*; Ireland, T.*; Kitajima, Fumio*; et al.
Science, 333(6046), p.1128 - 1131, 2011/08
Times Cited Count：130 Percentile：95.22(Multidisciplinary Sciences)A steroid surface materials record regolith processes and a history of cosmic-ray irradiation. Noble gas isotopes in three rocky grains from Itokawa have been determined. High concentrations of solar He, Ne, and Ar, as high as those in lunar soils, are released at variable temperatures from each sample. The isotopic compositions are essentially identical to those of solar wind but distinguishable in He relative abundance. These noble gas characteristics can be explained by repeated implantation and preferential loss of solar He by removal of weathered He-rich rim on the grain surface through friction among regolith grains on Itokawa. Residence time of regolith materials on Itokawa is alculated to be shorter than 10 Myr, suggesting that regolith materials of small asteroids would escape easily to space.
Hayashi, Katsuhiko; Noguchi, Akira; Kishi, Hirokazu; Kabayashi, Yasushi*; Nakama, Shigeo; Fujita, Tomoo; Naito, Morimasa; Tada, Hiroyuki*; Kumasaka, Hiroo*; Goke, Mitsuo*; et al.
JAEA-Research 2010-057, 101 Pages, 2011/03
JAEA-Research-2010-057.pdf:7.47MB
Cement-type materials that are used for supports or grouting at high-level radioactive waste disposal facilities leach into the groundwater and create a highly alkaline environment. Of concern in highly alkaline environments are the alteration of bentonite used as buffers or backfill materials, and of surrounding rock mass, and the increased uncertainty regarding the provision of performance of the disposal system over a long period of time. In this study, to reduce the quantity of cement-type materials that cause highly alkaline environments, technical feasibility of the support structure including the materials which considered the long-term performance of the HLW disposal system are discussed by using knowledge and technology accumulated in JAEA and Shimizu Construction. Moreover, based on the results, the problems remained in the application to the future HLW disposal institution are summarized.
Nakayama, Masashi; Sato, Haruo; Sugita, Yutaka; Noguchi, Akira
JAEA-Research 2010-055, 25 Pages, 2011/02
JAEA-Research-2010-055.pdf:2.08MB
In Japan, any high level radioactive waste repository is to be constructed at over 300 m depth below surface. Tunnel support is used for safety during the construction and operation, and shotcrete and concrete lining are used as the tunnel support. Concrete is a composite material comprised of aggregate, cement and various additives. Low alkaline cement has been developed for the long term stability of the barrier systems whose performance could be negatively affected by highly alkaline conditions arising due to cement used in a repository. JAEA has developed a low alkaline cement, named as HFSC, containing over 60wt% of SF and FA. JAEA are presently constructing an URL at Horonobe for research and development in the geosciences and repository engineering technology. HFSC was used experimentally as the shotcrete material in construction of part of the 140 m deep gallery in Horonobe URL. The objective of this experiment was to assess the performance of HFSC shotcrete in terms of mechanics, workability, durability, and so on. HFSC used in this experiment is composed of 40wt% OPC, 20wt% SF, and 40wt% FA. This composition was determined based on mechanical testing of various mixes of the above components. Because of the low OPC content, the strength of HFSC tends to be lower than that of OPC in normal concrete. The total length of tunnel using HFSC shotcrete is about 73 m and about 500 m
of HFSC was used. This experimental construction confirmed the workability of HFSC shotcrete. Although several in-situ experiments using low alkaline cement as shotcrete have been performed at a small scale, this application of HFSC at the Horonobe URL is the first full scale application of low alkaline cement in the construction of a URL in the world. In this report, we present detailed results of the in-situ construction test.
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Re-labeled antibody (A7) for radioimmunotherapy with rhenium(I) tricarbonyl core as a chelate siteOgawa, Kazuma*; Kawashima, Hidekazu*; Kinuya, Seigo*; Shiba, Kazuhiro*; Onoguchi, Masahisa*; Kimura, Hiroyuki*; Hashimoto, Kazuyuki; Odani, Akira*; Saji, Hideo*
Annals of Nuclear Medicine, 23(10), p.843 - 848, 2009/12
Times Cited Count：9 Percentile：31.42(Radiology, Nuclear Medicine & Medical Imaging)Rhenium is one of the most valuable elements for internal radiotherapy because Re have favorable physical characteristics. However, there are problems when proteins such as antibodies are used as carriers of Re. Labeling methods require the complicated processes. Therefore, we planned the preparation by a simple method and evaluation of a stable Re-labeled antibody. For this purpose, we selected Re(I) tricarbonyl complex as a chelating site. A7 was used as a model protein. Re-labeled A7 was prepared by directly reacting a Re(I) tricarbonyl precursor with A7. Re-(CO)
-A7 were prepared with radiochemical yields of 23-28%. After purification, Re-(CO)-A7 showed a radiochemical purity of over 95%. In biodistribution experiments, Re-labeled A7 showed high uptakes in the tumor.
Nakayama, Masashi; Kobayashi, Yasushi; Noguchi, Akira; Miura, Norihiko*; Noda, Masaru*; Iriya, Keishiro*; Hitomi, Takashi*
JAEA-Research 2009-036, 49 Pages, 2009/11
JAEA-Research-2009-036.pdf:20.34MB
In Horonobe Underground Research Laboratory (Horonobe URL) Project, construction practicality test with HFSC (Highly Fly-ash contained Silica-fume Cement) is planned in a part of the gallery. It is necessary to validate that HFSC has performance under the actual construction, before HFSC is placed in the gallery. The main tasks in 2008 are follows; (1) suggestion of mix design for liner concrete of shaft in Horonobe URL, (2) investigation of long term pH changes in order to use for modeling, and (3) an experiment for interaction between HFSC and ground water around Horonobe URL. (1) 4 types of mix proportion are designed for ordinary concrete and high strength concrete which contains polypropylene fiber or not. As early age strength, 5N/mm
is required because of concrete formwork. HFSC424 with low water binder ratio can fulfill this requirement in combination with super plasticizer. (2) pH and components of solid and liquid phase which were made in 2003, and stored in water were analyzed. And cement paste of shotcrete which are made in 2006 were also analyzed. In this pH of shotcrete is lower than other in situ concrete since accelerating agent may act as decreasing factor of pH. (3) An experiment which investigates dissolution of HFSC cement hydrates to ground water around Horonobe URL. According to the experiment, dissolving depth of HFSC is 4 times small comparing to Ordinary Portland Cement hydrates after 30th water exchange.
Hayashi, Kimio; Nakagawa, Tetsuya; Onose, Shoji; Ishida, Takuya; Nakamichi, Masaru; Katsuyama, Kozo; Iwamatsu, Shigemi; Hasegawa, Teiji; Kodaka, Hideo; Takatsu, Hideyuki; et al.
JAEA-Technology 2009-007, 168 Pages, 2009/03
JAEA-Technology-2009-007.pdf:31.88MB
In-pile functional tests of breeding blankets have been planned by Japan Atomic Energy Agency (JAEA), using a test blanket module (TBM) which will be loaded in the International Thermonuclear Experimental Reactor (ITER). In preparation for the in-pile functional tests, JAEA has been being performed irradiation experiments of lithium titanate (Li
TiO), which is the first candidate of solid breeder materials for the blanket of the demonstration reactor (DEMO) under designing in Japan. The present report describes (1) results of a detailed design and trial fabrication tests of a dismantling apparatus for irradiation capsules which were used in irradiation experiments by the Japan Materials Testing Reactor (JMTR) of JAEA, and (2) results of a preliminary investigation of a glove box facility for post-irradiation examinations (PIEs). In the detailed design of the dismantling apparatus, datailed specifications and the installation methods were examined, based on results of a conceptual design and basic design. In the trial fabrication, cutting tests were curried out by making a mockup of a cutting component. Furthermore, a preliminary investigation of a glove box facility was carried out in order to secure a facility for PIE work after the capsule dismantling, which revealed a technical feasibility.
Sato, Kaoru; Noguchi, Hiroshi; Endo, Akira; Emoto, Yutaka*; Koga, Sukehiko*; Saito, Kimiaki
Radiation Protection Dosimetry, 127(1-4), p.205 - 208, 2007/11
Times Cited Count：13 Percentile：66.15(Environmental Sciences)Calculation of specific absorbed fractions (SAFs) used in internal dosimetry requires a human phantom. However, radiation exposure occurs under various postures, which may affect the shape and location of organs. Therefore, it is important to clarify the effect of posture on SAFs. In the present study, a voxel phantom was developed on the basis of CT images in upright posture, and the difference of SAFs between supine and upright postures was investigated. The authors developed the voxel phantom of Japanese adult in supine posture named JM for the evaluation of SAFs of Japanese adult male. The subject, who was employed for the construction of JM, was selected as a volunteer again to obtain the CT images. The developed voxel phantom in upright posture was named JM2. The voxel size of JM2 is 0.98mm
0.98mm1mm, which is the same as that of JM. The fine voxels reproduce the shape and location of organs in the body realistically. It is possible to compare directly the change in the shape and location of organs due to the postures between JM and JM2, since the CT images for construction of the both phantoms were obtained from the identical person. This paper describes the physical characteristics of JM and JM2 and discusses the impact of posture on SAFs for photons in selected organs.
Ao, Hiroyuki; Akikawa, Hisashi; Ueno, Akira; Hasegawa, Kazuo; Yamazaki, Yoshishige; Ikegami, Masanori*; Noguchi, Shuichi*; Hayashizaki, Noriyosu*; Paramonov, V.*
Proceedings of 22nd International Linear Accelerator Conference (LINAC 2004), p.75 - 77, 2004/00
The J-PARC (Japan Proton Accelerator Research Complex) LINAC will be commissioned with energy of 181-MeV using 50-keV ion source, 3-MeV RFQ, 50-MeV DTL and 181-MeV SDTL (Separated DTL) on September 2006. It is planed to be upgraded by using a 400-MeV ACS (Annular Coupled Structure), which is a high-beta structure most suitable for the J-PARC, in a few years from the commissioning. The first ACS type cavity, which will be used as the first buncher between the SDTL and the ACS, is under fabrication. Detailed design and tuning procedure of ACS cavities has been studied with RF simulation analysis and cold-model measurements. The results of cold-model measurements, fabrication status, and related development items are described in this paper.
Endo, Akira; Sato, Kaoru; Noguchi, Hiroshi; Tanaka, Susumu; Iida, Takao*; Furuichi, Shinya*; Kanda, Yukio*; Oki, Yuichi*
Journal of Radioanalytical and Nuclear Chemistry, 256(2), p.231 - 237, 2003/05
Times Cited Count：7 Percentile：45.83(Chemistry, Analytical)Size distributions of 
Cl, 
Cl, 
Br and 
Br aerosols generated by irradiations of argon and krypton gases containing di-octyl phthalate (DOP) aerosols with 45MeV and 65MeV quasi-monoenergetic neutrons were measured to study the formation mechanism of radioactive particles in high energy radiation fields. Effects of the size distribution of the radioactive aerosols on the size of added DOP aerosols, the energy of irradiation neutrons and the kinds of nuclides were studied. The observed size distributions of the radioactive particles were explained by attachment of the radioactive atoms generated by the neutron-induced reactions to the DOP aerosols.
Kawai, Katsuo; Endo, Akira; Noguchi, Hiroshi
JAERI-Data/Code 2002-013, 66 Pages, 2002/05
JAERI-Data-Code-2002-013.pdf:2.75MBJAERI-Data-Code-2002-013-DoseCD.pdf:81.85MB
Effective dose coefficients by inhalation and ingestion have been calculated for 334 nuclides, including (1) nuclides with half-lives 
10min and their daughters that are not listed in ICRP Publications and (2) nuclides with half-lives 
10min that are produced in a spallation target. Dose calculation was carried out using a nuclear decay database DECDC and a decay data library newly compiled from the ENSDF. The dose coefficients were calculated with the computer code DOCAP based on the respiratory tract model and biokinetic model of ICRP. The calculated results are presented as tables, which are the same forms as those in ICRP Publs.68 and 72. The complete listings of the dose coefficients are arranged on a CD-ROM, DoseCD, as indexed tables for inhalation of ten particle sizes, ingestion and injection into blood for workers and members of the public. The dose coefficients calculated in the present study are useful to calculate internal doses for a variety of radionuclides produced in high energy proton accelerator facilities.
Endo, Akira; Noguchi, Hiroshi; Tanaka, Susumu; Kanda, Yukio*; Oki, Yuichi*; Iida, Takao*; Sato, Kaoru; Tsuda, Shuichi
Applied Radiation and Isotopes, 56(4), p.615 - 620, 2002/04
Times Cited Count：3 Percentile：23.41(Chemistry, Inorganic & Nuclear)Formation mechanism and size distribution of radioactive aerosol particles generated in a high-energy neutron field were studied in order to evaluate a particle size parameter for internal dose evaluation in high-energy accelerator facilities. Argon gas containing DOP aerosols was irradiated by a 65MeV quasi-monoenergetic neutron beam of TIARA. The number size distribution of the DOP aerosols and the activity-weighted size distribution of Cl and Cl aerosols, formed from the (n, 2np) and (n, np) reactions of 
Ar, were measured using an electrical low-pressure impactor. The activity-weighted size distribution of the radioactive aerosols was well explained by the simple attachment model of the radioactive atoms to the DOP aerosols.
Tanabe, Tetsuro*; Fujine, Michihiko*; Noguchi, Hiroshi*; Yagi, Yasufumi*; Hirano, Yoichi*; Shimizu, Hajime*; Akiba, Masato; Araki, Masanori; Kubota, Yusuke*; Miyahara, Akira*
Journal of Nuclear Materials, 200(1), p.120 - 127, 1993/03
Times Cited Count：9 Percentile：66.93(Materials Science, Multidisciplinary)no abstracts in English
Yokoyama, Sumi; Sato, Kaoru; Manabe, Kentaro; Endo, Akira; Noguchi, Hiroshi; Kaneko, Hirohisa; Oki, Yuichi*; Osada, Naoyuki*; Kanda, Yukio*; Iida, Takao*; et al.
no journal, ,
no abstracts in English
Osada, Naoyuki*; Oki, Yuichi*; Kanda, Yukio*; Yokoyama, Sumi; Sato, Kaoru; Manabe, Kentaro; Noguchi, Hiroshi; Endo, Akira; Tanaka, Susumu*; Kaneko, Hirohisa; et al.
no journal, ,
no abstracts in English
