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Collaborative Laboratories for Advanced Decommissioning Science; NAIS*
JAEA-Research 2025-004, 102 Pages, 2025/08
JAEA-Research-2025-004.pdf:3.33MB
For planning radioactive waste management at the Fukushima Daiichi Nuclear Power Station of the Tokyo Electric Power Company Holdings, Incorporated, estimation of radioactivity is essential with considering both contamination from the damaged fuel and activation during reactor operation; with regard to the latter, biological shielding is an important object due to its large amount. It is difficult to conduct field investigations or collect analysis samples at the site, hence the radioactivity should be estimated by calculative analysis with considering the actual conditions of the constituent materials, especially for activation of minor components and water, which affects the neutron flux. Besides it is important to assess the uncertainties involved in the calculation analysis. In this study, the trace composition and water content in the biological shielding concrete were investigated, and a three-dimensional computational model was constructed for the Unit 2 reactor building at the site to estimate the radioactivity concentration. In order to evaluate the uncertainty in the results, the factors contributing to the uncertainty were extracted and the uncertainty resulted from those factors on the calculation results, i.e. the influence of the diversity of the calculation model the parameters used in the calculation model. Based on the results, the dominant factors contributing to the uncertainty were extracted, and the handling as radioactive waste was discussed.
Collaborative Laboratories for Advanced Decommissioning Science; Tokyo Institute of Technology*
JAEA-Review 2024-026, 80 Pages, 2024/10
JAEA-Review-2024-026.pdf:1.96MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2022. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Study on degradation of fuel debris by combined effects of radiological, chemical, and biological functions" conducted from FY2019 to FY2022. In the project, radiochemists, nuclear chemists, nuclear physicists, material scientists, and environmental biologists are teamed to elucidate the mechanism of the degradation of fuel debris by combined effects of radiological, chemical, and biological functions.
Collaborative Laboratories for Advanced Decommissioning Science; Tokyo Institute of Technology*
JAEA-Review 2022-066, 91 Pages, 2023/03
JAEA-Review-2022-066.pdf:5.88MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Study on degradation of fuel debris by combined effects of radiological, chemical, and biological functions" conducted in FY2021. In the project, radiochemists, nuclear chemists, nuclear physicists, material scientists, and environmental biologists are teamed to elucidate the mechanism of the degradation of fuel debris by combined effects of radiological, chemical, and biological functions. In fiscal year 2021, the members of the project team have conducted on the microbial degradation of the simulated fuel debris under 
-ray irradiation, complex formation of pentavalent uranium, construction of microchannel system to detect micro-particles and the simulated fuel debris, sorption of tetravalent elements ...
Collaborative Laboratories for Advanced Decommissioning Science; Tokyo Institute of Technology*
JAEA-Review 2022-005, 93 Pages, 2022/06
JAEA-Review-2022-005.pdf:6.95MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Study on degradation of fuel debris by combined effects of radiological, chemical, and biological functions" conducted in FY2020. In the project, radiochemists, nuclear chemists, nuclear physicists, material scientists, and environmental biologists are teamed to elucidate the mechanism of the degradation of fuel debris by combined effects of radiological, chemical, and biological functions. In fiscal year 2020, the members of the project team have conducted on the degradation of He ions irradiated simulated fuel debris, complex formation of tetravalent elements, uranium (VI) detection in microchannel, sorption of trivalent elements by iron bearing materials, and microbial degradation by model microorganisms …
Furuta, Takuya
Igaku Butsuri, 41(4), P. 194, 2021/12
Number of medical uses of Particle and Heavy Ion Transport code System (PHITS) has been increased due to the recent high demands of medical use of radiations. The summary of such research works was described in the review article on medical application of Particle and Heavy Ion Transport code System PHITS published in Radiological Physics and Technology in 2021. There was a request from the editorial board of Japan Society of Medical Physics (JSMP) for writing an introductory article of this article in their internal journal. The research works on medical applications described in the review article, useful functions for medical application in PHITS, and newly opened user forum of PHITS have been introduced.
Furuta, Takuya; Sato, Tatsuhiko
Radiological Physics and Technology, 14(3), p.215 - 225, 2021/09
Number of the PHITS users has steadily increased since 2010 from when it is officially counted. Among them, increase of new users in medical physics is outstanding. Many research works in medical physics using PHITS have been published and the applications are widely spread in different fields such as applications to different types of radiotherapy, shielding calculations of medical facilities, application to radiation biology, and research and development of medical tools. In this article, we will introduce useful functions for medical application in PHITS by referring to examples of various medical applications.
Kochiyama, Mami; Okada, Shota; Sakai, Akihiro
JAEA-Technology 2021-010, 61 Pages, 2021/07
JAEA-Technology-2021-010.pdf:3.56MBJAEA-Technology-2021-010(errata).pdf:0.75MB
It is necessary to evaluate the radioactivity inventory in wastes in order to dispose of radioactive wastes generated from dismantling nuclear reactor in the shallow ground. In this report, we examined radioactivity evaluation method for near surface disposal about biological shield concrete near the core generated from the dismantling of JPDR. We calculated radioactive concentration of the target biological concrete using the DORT code and the ORIGEN-S code, and we estimated radioactivity concentration Di (Bq/t). For DORT calculation, the cross-section library created from the MATXSLIB-J40 file from JENDL-4.0 was used, and for ORIGEN-S, the attached library of SCALE6.0 was used. As a result of comparing the calculation results of the radioactivity concentration with the past measured values in the radial direction and the vertical direction, we found that the trends were generally the same. We calculated radioactive concentration of the target biological concrete Di (Bq/t), and we compared with the estimated Ci (Bq/t) equivalent to the dose criteria of trench disposal calculated for 140 nuclides. As a result we inferred that the except for about 2% of target waste could be disposed of in the trench disposal facility. We also preselected important nuclides for trench disposal based on the ratios (Di/Ci) for each nuclide, H-3, C-14, Cl-36, Ca-41, Co-60, Sr-90, Eu-152 and Cs-137 were selected as important nuclides.
Collaborative Laboratories for Advanced Decommissioning Science; Tokyo Institute of Technology*
JAEA-Review 2020-046, 69 Pages, 2021/01
JAEA-Review-2020-046.pdf:4.81MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2019. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Study on Degradation of Fuel Debris by Combined Effects of Radiological, Chemical, and Biological Functions". In the project, radiochemists, nuclear chemists, nuclear physicists, material scientists, and environmental biologists are teamed to elucidate the mechanism of the degradation of fuel debris by combined effects of radiological, chemical, and biological Functions. In FY2019, the members of the project team focused on literature survey, preliminary experiments, and installation of experimental devices for the planned research.
Sato, Tatsuhiko; Yokoya, Ritsuko; Niita, Koji*
Radiation Protection Dosimetry, 122(1-4), p.41 - 45, 2006/12
Times Cited Count：82 Percentile：97.34(Environmental Sciences)Estimation of biological effects due to exposure of HZE particles is one of the key issues in the planning of long-term space missions and heavy ion cancer therapies. Detailed information on the specific energy distributions around their tracks is indispensable in the issue. We therefore calculated the specific energy distributions in liquid water around the tracks of protons and several kinds of heavy ions with energies from 1 MeV/n to 100 GeV/n. The calculations were performed by a Monte Carlo electron track structure simulation code coupled with the Katz's delta-ray production model. An analytical function to reproduce the simulation results has been developed in order to predict the distribution for all kinds of heavy ions with wide energy ranges. By incorporated into the Particle and Heavy Ion Transport code System PHITS, the function enables us to calculate the specific energy distribution in macroscopic matters such as specified organs of astronauts or tumor of patients within a short computational time.
by BIX-3, a single-crystal diffractometer for biomacromoleculesKurihara, Kazuo; Tanaka, Ichiro*; Chatake, Toshiyuki*; Adams, M. W. W.*; Jenney, F. E. Jr.*; Moiseeva, N.*; Bau, R.*; Niimura, Nobuo
Proceedings of the National Academy of Sciences of the United States of America, 101(31), p.11215 - 11220, 2004/08
Times Cited Count：52 Percentile：62.29(Multidisciplinary Sciences)The structure of a rubredoxin (Rd) from , an organism that grows optimally at 100 
C, was determined using the neutron single-crystal diffractometer for biological macromolecules (BIX-3) at the JRR-3 reactor of JAERI. Data were collected at room temperature up to a resolution of 1.5 
, and the completeness of the data set was 81.9 %. The model contains 306 H atoms and 50 D atoms. A total of 37 hydration water molecules were identified. The model has been refined to final agreement factors of 
= 18.6 % and 
= 21.7 %. Several orientations of the O-D bonds of side chains, whose assignments from X-ray data were previously ambiguous, were clearly visible in the neutron structure. While most backbone N-H bonds had undergone some degree of H/D exchange throughout the molecule, five H atom positions still had distinctly negative (H) peaks. The neutron Fourier maps clearly showed the details of an extensive set of H bonds involving the ND
terminus that may contribute to the unusual thermostability of this molecule.
to ion beam radiationHayashi, Hirotaka*; Wada, Seiichi; Funayama, Tomoo; Narumi, Issei; Kobayashi, Yasuhiko; Watanabe, Hiroshi*; Furuta, Masakazu*; Uehara, Kaku*
Journal of Eukaryotic Microbiology, 51(3), p.321 - 324, 2004/06
Times Cited Count：5 Percentile：6.19(Microbiology)no abstracts in English
Fukuda, Mitsuhiro; Ito, Hisayoshi; Oshima, Takeshi; Saido, Masahiro; Tanaka, Atsushi
Charged Particle and Photon Interactions with Matter, p.813 - 859, 2003/11
An ion beam has been widely applied to a variety of research fields of materials, space, and bio-sciences. Notable results, which were hard to obtain in applications of a ray and an electron beam, have been produced by the ion beam application. Ion beams interacting with matter have such superior properties as highly localized ionization and excitation, production of secondary particles, implantation of different atoms, and nuclear transmutation of constituent atoms. Skillful utilization of the ion beam properties makes remarkable progress in creation of new materials and precise investigation of matters. The ion beam irradiation research facility, TIARA, was established in 1993 at JAERI for extensive applications of ion beams. An accelerator complex provides light to heavy ion beams with a broad energy range from keV to GeV. Various ion beam technologies pioneering the ion beam applications have been developed at TIARA. In this paper, new applications of accelerated ion beams to material, space, and biological science and engineering carried out mainly at TIARA are reviewed.
Maekawa, Fujio; Tamura, Masaya
Proceedings of ICANS-XVI, Volume 3, p.1051 - 1058, 2003/07
A three-dimensional (3-D) shielding calculation model for MCNPX was produced for shielding design of 1-MW JSNS. The model included simplified target-moderator-reflector assembly, helium-vessel and neutron beam extraction pipes, shutters, shield blocks, gaps and void spaces between these components, and so on, and could treat streaming effects precisely. The particle splitting and kill method with cell importance parameters was adopted as a variance reduction method. The cell importance parameters for such a large target station of about 15 m in diameter and 12 m in hight in which neutron fluxes attenuated more than 12 orders of magnitude could be determined appropriately by automated iteration calculations. This calculation procedure enabled detailed 3-D shielding design calculations for the whole target station in a short time, i.e., within 2 days, and contributed for progress of shielding designs of JSNS.
Endo, Akira; Yamaguchi, Yasuhiro
Radiation Research, 159(4), p.535 - 542, 2003/04
Times Cited Count：15 Percentile：40.65(Biology)The first criticality accident in Japan occurred in a uranium processing plant in Tokai-mura in September, 1999. In this accident, two workers on the site were heterogeneously exposed to neutrons and rays produced by the nuclear fission. Heterogeneous exposure influenced the clinical course observed in the skin and organs of these workers. By request from medical groups, we attempted to clarify the dose distribution of the two heavily exposed workers with the aid of computer simulation, which is currently the only means by which to address this complicated problem. This paper presents elucidated skin dose distributions, depth dose distributions inside the trunk, and neutron-to- dose ratios.
Kume, Tamikazu
Proceedings of 9th International Conference on Radiation Curing (RadTech Asia '03) (CD-ROM), 4 Pages, 2003/00
Utilization of bio-resources by radiation has been investigated for recycling the natural resources and reducing the environmental pollution. Polysaccharides such as chitosan and sodium alginate were easily degraded by irradiation and induced various kinds of biological activities, i.g. anti-microbial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction. Radiation degraded chitosan was effective to enhance the growth of plants in tissue culture. It was demonstrated that the liquid sample irradiation system using low energy EB was effective for the preparation of degraded polysaccharides. Methylcellulose (MC) can be crosslinked under certain radiation condition as same as carboxymethylcellulose (CMC) and produced the biodegradable hydrogel for medical and agricultural use. Treatment of soybean seeds by low energy EB enhanced the growth and the number of rhizobia on the root.
Cl in biological shield concrete using pyrohydrolysis and liquid scintillation countingIto, Mitsuo; Watanabe, Kazuo; Hatakeyama, Mutsuo; Tachibana, Mitsuo
Analyst, 127(7), p.964 - 966, 2002/06
Times Cited Count：16 Percentile：43.54(Chemistry, Analytical)A method for the determination of Cl-36 in biological shield concrete of nuclear reactor was developed. Cl in the concrete sample was extracted quantitatively by pyrohydrolysis at 900 ºC and recovered in Na2CO3 solution for subsequent measurement of Cl-36 by liquid scintillation counting. WO3 was used as an accelerator in the pyrohydrolysis. The Cl extraction procedure was optimized by investigating experimental conditions with the use of ion chromatography and its recovery was evaluated by the analysis of the geochemical reference samples. Detection limit of Cl-36 was 0.02 Bq g-1 for sample weight of 2g. Relative standard deviation was 3 – 7 % for the samples containing 0.5 Bq g-1 levels of 36Cl. The newly developed method was applied to determine Cl-36 in biological shield concrete of the Japan Power Demonstration Reactor.
biological effectiveness of JRR-4 epithermal neutron beam; Experiment under free air beam and in water phantom (Cooperative research)Yamamoto, Tetsuya*; Yamamoto, Kazuyoshi; Matsumura, Akira*; Kumada, Hiroaki; Kishi, Toshiaki; Hori, Naohiko; Torii, Yoshiya; Horiguchi, Yoji; Nose, Tadao*
JAERI-Research 2002-011, 56 Pages, 2002/05
JAERI-Research-2002-011.pdf:3.17MB
The surviving curve and RBE of dose components generated in boron neutron capture therapy (BNCT) were separately determined in neutron beams at JRR-4. Surviving fraction of V79 cell with or without 
B was obtained using an epithermal neutron beam (ENB), a mixed thermal-epithermal neutron beam (TNB-1), and a thermal neutron beam(TNB-2), which were used or planned to use for clinical trial. The cell killing effect of these beams depended highly on the neutron beam used, according to the epithermal and fast neutron content in the beam. RBE of the boron capture were 3.99
0.24, 3.040.19 and 1.430.08, RBE of the high-LET dose components based were 2.500.32, 2.340.30 and 2.170.28 for ENB, TNB-1 and TNB-2, respectively. The experimental determination of biological effectiveness factor outlined in this paper is applicable to the dose calculation for each dose component of the neutron beams and contribute to an accurate RBE as comparison with a neutron beam at a different facility employed in ongoing and planned BNCT clinical trials.
Maekawa, Fujio; Teshigawara, Makoto; Takada, Hiroshi; Furusaka, Michihiro*; Watanabe, Noboru
JAERI-Tech 2002-035, 68 Pages, 2002/03
JAERI-Tech-2002-035.pdf:4.76MB
no abstracts in English
Ca in biological-shield concrete by low-energy X-ray spectrometryIto, Mitsuo; Watanabe, Kazuo; Hatakeyama, Mutsuo; Tachibana, Mitsuo
Analytical and Bioanalytical Chemistry, 372(5-6), p.532 - 536, 2002/03
Times Cited Count：17 Percentile：45.47(Biochemical Research Methods)An X-ray spectrometry method has been developed for the determination of Ca-41 in the biological shield concrete of nuclear reactors. To isolate Ca from other elements, the concrete sample was first decomposed with nitric, hydrofluoric and perchloric acids. Calcium was then separated from other coexisting radionuclides by ion-exchange chromatography and recovered as an oxalate precipitate. X rays at 3.3 keV from Ca-41 in the calcium oxalate pellet were measured. Detection efficiency of the X-ray measurement at 3.3 keV was calculated from those obtained by measuring Fe-55 standard pellets at 5.9 keV using mass absorption coefficients of the calcium oxalate pellet at each X-ray energy value. A lower limit of determination of 8 Bq g-1 was obtained for a sample weight of 1 g.
Tanaka, Ichiro; Kurihara, Kazuo; Chatake, Toshiyuki; Niimura, Nobuo
Journal of Applied Crystallography, 35(Part1), p.34 - 40, 2002/02
A high performance neutron diffractometer for biological crystallography (BIX-3) has been constructed at JRR-3M in Japan Atomic Energy Research Institute (JAERI) in order to determine the hydrogen positions in biological macromolecules. It uses several recent technical innovations, such as a neutron imaging plate and an elastically bent silicon monochromator developed by the authors. These have made it possible to realize a compact vertical arrangement of the diffractometer. Diffraction data have been collected from the proteins rubredoxin and myoglobin in about one month, to a resolution of 1.5, good enough to identify the hydrogen atoms with high accuracy. By adopting a crystal-step scan method for measuring Bragg diffraction intensities, the signal to noise ratio was much better than that of the Laue method. This shows that BIX-3 is one of the best-performing machines for neutron protein crystallography in the world currently.
