Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 83

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

MIRS: an imaging spectrometer for the MMX mission

Barucci, M. A.*; Reess, J.-M.*; Bernardi, P.*; Doressoundiram, A.*; Fornasier, S.*; Le Du, M.*; Iwata, Takahiro*; Nakagawa, Hiromu*; Nakamura, Tomoki*; Andr$'e$, Y.*; et al.

Earth, Planets and Space (Internet), 73(1), p.211_1 - 211_28, 2021/12

 Times Cited Count:8 Percentile:81.82(Geosciences, Multidisciplinary)

The MMX InfraRed Spectrometer (MIRS) is an imaging spectrometer on board of MMX JAXA mission. MIRS is built at LESIA-Paris Observatory in collaboration with four other French laboratories, collaboration and financial support of CNES and close collaboration with JAXA and MELCO. The instrument is designed to fully accomplish MMX's scientific and measurement objectives. MIRS will remotely provide near-infrared spectral maps of Phobos and Deimos containing compositional diagnostic spectral features that will be used to analyze the surface composition and to support the sampling site selection. MIRS will also study Mars atmosphere, in particular to spatial and temporal changes such as clouds, dust and water vapor.

Journal Articles

Role of advection in atmospheric ammonia; A Case study at a Japanese lake basin influenced by agricultural ammonia sources

Kubota, Tomohiro; Kuroda, Hisao*; Watanabe, Mirai*; Takahashi, Akiko*; Nakazato, Ryoji*; Tarui, Mika*; Matsumoto, Shunichi*; Nakagawa, Keita*; Numata, Yasuko*; Ouchi, Takao*; et al.

Atmospheric Environment, 243, p.117856_1 - 117856_9, 2020/12

 Times Cited Count:2 Percentile:10.2(Environmental Sciences)

The dry and wet depositions of atmospheric ammonia (NH$$_{3}$$) is one of the important pathways of nitrogen loads to aquatic ecosystems. Crop and livestock agriculture, one of the largest emitters of NH$$_{3}$$ in Asian countries, are known to cause high spatial and seasonal variation of NH$$_{3}$$ and influence the surrounding lake basin areas via its dry and wet deposition. However, the spatial characteristics of the NH$$_{3}$$ concentration in basin scale are not completely understood for regulation in NH$$_{3}$$ emission. Here we aim to clarify dominant factors of spatial and seasonal variations of the NH$$_{3}$$ concentration in a eutrophic lake basin surrounded by agricultural areas in Japan. Passive sampling over various land use categories in the basin was conducted at 36 sites in total from October 2018 to January 2020. Interestingly, the observed NH$$_{3}$$ concentration near the livestock houses were higher in winter than summer, which was inconsistent with knowledge of seasonal changes of current NH$$_{3}$$ emission inventory based on temperature-driven volatilization process. Comparing monthly NH$$_{3}$$ concentrations with various meteorological factors, we suggested the importance of seasonal advection of NH$$_{3}$$ from high emission sources to which has been rarely paid attention by the previous past studies. As for this, should be considered for lake ecosystem management since deposition of NH$$_{3}$$ is known to be closely related to the ecological processes such as phytoplankton blooming.

JAEA Reports

Biosphere assessment methodology commonly applicable to various disposal concepts

Kato, Tomoko; Fukaya, Yukiko*; Sugiyama, Takeshi*; Nakai, Kunihiro*; Oda, Chie; Oi, Takao

JAEA-Data/Code 2019-002, 162 Pages, 2019/03

JAEA-Data-Code-2019-002.pdf:2.78MB

The radioactive waste generated from Fukushima Daiichi nuclear power station (FDNPS) accident have features such as wide range of radioactivity level (from low to high) and huge amount etc. It would be necessary for the waste from the FDNPS accident to develop suitable disposal concept and to be disposed safely and reasonably. When considering such appropriate disposal concepts in site-generic phase, it is necessary to appropriately develop models and parameters depending on the disposal concepts, such as disposal depth and specification of engineered barrier. In addition, it is desirable to evaluate the safety of repository with common models and parameters independent on the disposal concepts. In the safety assessment of disposal, it is useful to show the difference in performance of repository with "dose" as an indicator of safety assessment. Biosphere model and parameter set and flux-to-dose conversion factors calculated using them are originally dependent on the disposal concepts. However, the biosphere models and the parameter set in safety assessment of near-surface disposal, sub-surface disposal and geological disposal are prepared in each case, and are different according to the age and purpose of the discussion. In this study, an example of biosphere model and parameter-set of groundwater sceinario commonly applicable to various disposal concepts were shown, to calculate flux-to-dose conversion factors, as common indicators independent to disposal concept. And, a set of flux-to-dose conversion factors was also calculated by using the commonly available biosphere model and parameter set. By applying the flux-to-dose conversion factors, it is possible to compare the performance of disposal concepts to the waste generated from FDNPS accident, focusing on the parts depending on the disposal concepts.

Journal Articles

Probabilistic risk assessment method development for high temperature gas-cooled reactors, 1; Project overviews

Sato, Hiroyuki; Nishida, Akemi; Ohashi, Hirofumi; Muramatsu, Ken*; Muta, Hitoshi*; Itoi, Tatsuya*; Takada, Tsuyoshi*; Hida, Takenori*; Tanabe, Masayuki*; Yamamoto, Tsuyoshi*; et al.

Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 7 Pages, 2017/04

JAEA, in conjunction with Tokyo City University, The University of Tokyo and JGC Corporation, have started development of a PRA method considering the safety and design features of HTGR. The primary objective of the project is to develop a seismic PRA method which enables to provide a reasonably complete identification of accident scenario including a loss of safety function in passive system, structure and components. In addition, we aim to develop a basis for guidance to implement the PRA. This paper provides the overview of the activities including development of a system analysis method for multiple failures, a component failure data using the operation and maintenance experience in the HTTR, seismic fragility evaluation method, and mechanistic source term evaluation method considering failures in core graphite components and reactor building.

Journal Articles

Probabilistic risk assessment method development for high temperature gas-cooled reactors, 2; Development of accident sequence analysis methodology

Matsuda, Kosuke*; Muramatsu, Ken*; Muta, Hitoshi*; Sato, Hiroyuki; Nishida, Akemi; Ohashi, Hirofumi; Itoi, Tatsuya*; Takada, Tsuyoshi*; Hida, Takenori*; Tanabe, Masayuki*; et al.

Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 7 Pages, 2017/04

This paper proposes a set of procedures for accident sequence analysis in seismic PRAs of HTGRs that can consider the unique accident progression characteristics of HTGRs. Main features of our proposed procedure are as follows: (1) Systematic analysis techniques including Master Logic Diagrams are used to ensure reasonable completeness in identification of initiating events and classification of accident sequences, (2) Information on factors that govern the accident progression and source terms are effectively reflected to the construction of event trees for delineation of accident sequences, and (3) Frequency quantification of seismically-initiated accident sequence frequencies that involve multiplepipe ruptures are made with the use of the Direct Quantification of Fault Trees by Monte Carlo (DQFM) method by a computer code SECOM-DQFM.

Journal Articles

Estimation of the inventory of the radioactive wastes in Fukushima Daiichi NPS with a radionuclide transport model in the contaminated water

Shibata, Atsuhiro; Koma, Yoshikazu; Oi, Takao

Journal of Nuclear Science and Technology, 53(12), p.1933 - 1942, 2016/12

 Times Cited Count:18 Percentile:85.95(Nuclear Science & Technology)

JAEA Reports

Analysis results of contaminated water and rubbles/soils in Fukushima Daiichi Nuclear Power Station; The Release of FY2014 edition of the analysis results of contaminated water and rubbles/soils

Asami, Makoto; Watahiki, Hiromi; Oi, Takao; Shibata, Atsuhiro; Ashida, Takashi

JAEA-Data/Code 2015-020, 80 Pages, 2015/11

JAEA-Data-Code-2015-020.pdf:45.07MB
JAEA-Data-Code-2015-020-appendix(DVD-ROM).zip:602.44MB

FY2014 edition of the analysis results on contaminated water in the circulating system and on rubbles/soils of Fukushima Daiichi Nuclear Power Station (1F NPS) was compiled. This technical report shows the function of the electronic file of the FY2014 edition of the analysis results on contaminated water and on rubbles/soils and presents the user manual with example and gives the electronic file by appendix CD.

JAEA Reports

Development of a database on analyses of contaminated water in Fukushima Daiichi Nuclear Power Station; The Release of FY2013 edition of the database on the analyses of contaminated water

Asami, Makoto; Watahiki, Hiromi; Oi, Takao; Makino, Hitoshi; Shibata, Atsuhiro; Kameo, Yutaka; Meguro, Yoshihiro; Ashida, Takashi

JAEA-Data/Code 2014-016, 37 Pages, 2014/09

JAEA-Data-Code-2014-016.pdf:37.04MB
JAEA-Data-Code-2014-016-appendix(CD-ROM).zip:60.46MB

A database on the analyses of samples obtained from contaminated water in the circulating system of Fukushima Daiichi Nuclear Power Station was built. This database contains the analyses of 25 samples of JAEA and 313 samples of TEPCO which have been published in FY 2011 to FY 2013. Also, as well as the analyses on contaminated water, the information on the stored and treated amount in accumulated water and the amount of produced waste, which has been published by TEPCO and which might be required in order to estimate the inventory of secondary waste (sludge, used vessels) generated by treatment of contaminated water are contained in this database. This technical report shows the function of this database and user manual with example and presents the FY2013 edition of database by appendix CD.

JAEA Reports

Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage, 2; Progress report on NUMO-JAEA collaborative research in FY2012 (Joint research)

Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Hayano, Akira; Makino, Hitoshi; Wakasugi, Keiichiro; Mitsui, Seiichiro; Oda, Chie; Kitamura, Akira; Osawa, Hideaki; et al.

JAEA-Research 2013-037, 455 Pages, 2013/12

JAEA-Research-2013-037.pdf:42.0MB

Following FY2011, JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation stage. With regard to (1) study on rock suitability in terms of hydrology, the tree diagram of methodology of groundwater travel time has been extended for crystalline rock, in addition, tree diagram for sedimentary rock newly has been organized. With regard to (2) study on scenario development, the existing approach has been improved in terms of a practical task, and applied and tested for near field focusing on the buffer. In addition, the uncertainty of some important processes and its impact on safety functions are discussed though analysis. With regard to (3) study on setting radionuclide migration parameters, the approaches for parameter setting have been developed for sorption for rocks and solubility, and applied and tested through parameter setting exercises for key radionuclides.

JAEA Reports

Enhancement of the methodology of repository design and post-closure performance assessment for preliminary investigation stage; Progress report on NUMO-JAEA collaborative research in FY2011 (Joint research)

Shibata, Masahiro; Sawada, Atsushi; Tachi, Yukio; Makino, Hitoshi; Hayano, Akira; Mitsui, Seiichiro; Taniguchi, Naoki; Oda, Chie; Kitamura, Akira; Osawa, Hideaki; et al.

JAEA-Research 2012-032, 298 Pages, 2012/09

JAEA-Research-2012-032.pdf:33.68MB

JAEA and NUMO have conducted a collaborative research work which is designed to enhance the methodology of repository design and performance assessment in preliminary investigation phase. The topics and the conducted research are follows; (1) Study on selection of host rock: in terms of hydraulic properties, items for assessing rock property, and assessment methodology of groundwater travel time has been organized with interaction from site investigation. (2) Study on development of scenario: the existing approach has been embodied, in addition, the phenomenological understanding regarding dissolution of and nuclide release from vitrified waste, corrosion of the overpack, long-term performance of the buffer are summarized. (3) Study on setting nuclide migration parameters: the approach for parameter setting has been improved for sorption and diffusion coefficient of buffer/rock, and applied and tested for parameter setting of key radionuclides. (4) Study on ensuring quality of knowledge: framework for ensuring quality of knowledge has been studied and examined aimed at the likely disposal facility condition.

Journal Articles

Identified charged hadron production in $$p + p$$ collisions at $$sqrt{s}$$ = 200 and 62.4 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06

 Times Cited Count:176 Percentile:99.41(Physics, Nuclear)

Transverse momentum distributions and yields for $$pi^{pm}, K^{pm}, p$$, and $$bar{p}$$ in $$p + p$$ collisions at $$sqrt{s}$$ = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different $$sqrt{s}$$ collisions. We also present the scaling properties such as $$m_T$$ and $$x_T$$ scaling and discuss the mechanism of the particle production in $$p + p$$ collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.

Journal Articles

Azimuthal correlations of electrons from heavy-flavor decay with hadrons in $$p+p$$ and Au+Au collisions at $$sqrt{s_{NN}}$$ = 200 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Aramaki, Y.*; et al.

Physical Review C, 83(4), p.044912_1 - 044912_16, 2011/04

 Times Cited Count:7 Percentile:49.81(Physics, Nuclear)

Measurements of electrons from the decay of open-heavy-flavor mesons have shown that the yields are suppressed in Au+Au collisions compared to expectations from binary-scaled $$p+p$$ collisions. Here we extend these studies to two particle correlations where one particle is an electron from the decay of a heavy flavor meson and the other is a charged hadron from either the decay of the heavy meson or from jet fragmentation. These measurements provide more detailed information about the interaction between heavy quarks and the quark-gluon matter. We find the away-side-jet shape and yield to be modified in Au+Au collisions compared to $$p+p$$ collisions.

JAEA Reports

A Study for the safety evaluation of geological disposal of TRU waste and influence on disposal site design by change of amount of TRU waste (Joint research)

Hasegawa, Makoto; Kondo, Hitoshi; Kamei, Gento; Hirano, Fumio; Mihara, Morihiro; Takahashi, Kuniaki; Funabashi, Hideyuki; Kawatsuma, Shinji; Ueda, Hiroyoshi*; Oi, Takao*; et al.

JAEA-Research 2011-003, 47 Pages, 2011/02

JAEA-Research-2011-003.pdf:3.99MB

In 2009, NUMO and JAEA set up a technical commission to investigate the reasonable TRU waste disposal following a cooperation agreement between these two organizations. In this report, the calculation result of radionuclide transport for a TRU waste geological disposal system was described, by using the TIGER code and the GoldSim code at identical terms. Comparing the calculation result, a big difference was not seen. Therefore, the reliability of both codes was able to be confirmed. Moreover, the influence on the disposal site design (Disposal capacity: 19,000 m$$^{3}$$) was examined when 10% of the amount of TRU waste increased. As a result, it was confirmed that the influence of the site design was very little based on the concept of the Second Progress Report on Research and Development for TRU Waste Disposal in Japan.

Journal Articles

Study on evaluation method of potentional geological environmenral changes of "uplift and erosion" for performance assessment on a high level radioactive waste geological disposal system

Kawamura, Makoto; Ebashi, Takeshi; Makino, Hitoshi; Niizato, Tadafumi; Yasue, Kenichi; Inagaki, Manabu; Oi, Takao

Oyo Chishitsu, 51(5), p.229 - 240, 2010/12

Uplift, subsidence, denudation, and sedimentation are phenomena over long-term in a regional scale. It is difficult to ignore the impacts of those phenomena on a disposal system completely in long-term. Therefore, type and extent of the impacts on geological and disposal environmental conditions, and disposal systems need to be evaluated quantitatively in order to develop perturbation scenarios. We have been developing a systematic methodology to develop perturbation scenarios based on the appropriate understanding of those phenomena. The variety of the change of geological environment and evolution pattern of the environment, which are caused by the variation of the uplift, subsidence, denudation, sedimentation phenomena and those rates, are understood by arranging the information in the framework of the thermal-hydrological-mechanical-chemical-geometrical (T-H-M-C-G) system, and the impacts of those environmental change to the performance of the repository system are also examined by using the T-H-M-C-G system. In this study, firstly, the potential changes of the geological environment were identified by examination of possible combinations of the uplift/denudation and subsidence/ sedimentation. The effects of the initial environmental condition are also considered. Geohistorical information and View of Modern analogue theory should be used in this stage. This procedure is essential to set up the scenarios regarding uplift/denudation and subsidence/sedimentation, to clarify the trend and/or range of the change of the geological environmental conditions. Then, the phenomena which give the large impacts to a disposal system were extracted based on the T-H-M-C-G system. By applying the developed framework which deals with the impacts on the HLW disposal system realistic view and builds evaluation scenarios and models based on step wise manner, we acquired the prospect that realistic uplift and denudation scenario could be built to this examination procedure.

JAEA Reports

Study on perturbation scenario for potential effect of uplift, denudation, subsidence and sedimentation on a HLW disposal system

Kawamura, Makoto; Ebashi, Takeshi; Makino, Hitoshi; Niizato, Tadafumi; Yasue, Kenichi; Oi, Takao

JAEA-Research 2008-119, 32 Pages, 2009/03

JAEA-Research-2008-119.pdf:8.06MB

Uplift, subsidence, denudation, and sedimentation are phenomena over long-term in a regional scale. It is difficult to ignore the impacts of those phenomena on a disposal system completely in long-term. Therefore, type and extent of the impacts on geological and disposal environmental conditions, and disposal systems need to be evaluated quantitatively in order to develop perturbation scenarios. JAEA has been developing a systematic methodology to develop perturbation scenarios based on the appropriate understanding of those phenomena. The variety of the change of geological environment and evolution pattern of the environment, which are caused by the variation of the uplift, subsidence, denudation, sedimentation phenomena and those rates, are understood by arranging the information in the framework of the thermal-hydrological-mechanical-chemical-geometrical (T-H-M-C-G) system, and the impacts of those environmental change to the performance of the repository system are also examined by using the T-H-M-C-G system. In this study, firstly, the potential changes of the geological environment were identified by examination of possible combinations of the uplift/denudation and subsidence/ sedimentation. The effects of the initial environmental condition are also considered. Geohistorical information and Modern analogue theory should be used in this stage. This procedure is essential to set up the scenarios regarding uplift/denudation and subsidence/sedimentation, to clarify the trend and/or range of the change of the geological environmental conditions. Then, the phenomena which give the large impacts to a disposal system were extracted based on the T-H-M-C-G system. By applying the developed framework which deals with the impacts on the HLW disposal system realistic view and builds evaluation scenarios and models based on step wise manner, we acquired the prospect that realistic uplift and denudation scenario could be built to this examination procedure.

JAEA Reports

A Demonstration of the usefulness of the systematic approach to evaluate the importance of concerns affecting the geological disposal of radioactive wastes

Oi, Takao; Inagaki, Manabu; Kawamura, Makoto; Ebashi, Takeshi

JAEA-Research 2008-111, 32 Pages, 2009/03

JAEA-Research-2008-111.pdf:3.95MB

A demonstration of the usefulness of the systematic approach to evaluate the importance of concerns affecting the geological disposal of radioactive wastes.

Journal Articles

Assessment approach for a safety margin of parameters on the high-level radioactive waste disposal

Ebashi, Takeshi; Koo, Shigeru*; Oi, Takao

Genshiryoku Bakkuendo Kenkyu, 15(2), p.99 - 115, 2009/03

In order to demonstrate the robustness of the design of a high-level waste (HLW) disposal system, an important measure is to preliminarily set parameter values, which take into account safety margins for an acceptable dose. In evaluating the safety margin, it is necessary to estimate a range of parameters for an acceptable dose by a sensitivity analysis based on the appropriate conditions for each scenario. In this study, the comprehensive sensitivity analysis method was applied to performance assessment of a HLW disposal system. This paper presents the approach to assess a safety margin for parameters. As a result, safety margins for the parameters of the engineered barrier system (glass dissolution rate, overpack failure time, buffer thickness) were illustrated under conservative conditions of the natural barrier. Such an approach will provide useful information for scenario analysis and offer insights into the design and construction of a robust system for HLW disposal concept.

Journal Articles

Development of the methodology on priority of element-specific biosphere parameters for geological disposal applicable to any proposed repository site

Kato, Tomoko; Suzuki, Yuji*; Oi, Takao

Hoken Butsuri, 44(1), p.72 - 79, 2009/03

It is difficult to acquire all of biosphere parameters at the repository site because we have to deal with several hundreds of the parameters in one calculation case of the biosphere assessment. Before site-specific activities, it is important to develop the data acquisition methodology of biosphere parameters applicable to any proposed repository site. In this study, we developed the methodology for identification of the priority of the parameters for the effective data acquisition of biosphere parameters at the site. First of all, flow diagram was constructed to evaluate the availability of the existing generic biosphere dataset. We found that it was effective for the data acquisition at the site to focus on the element-specific parameters with the existing dataset. Secondly, we identified the priority of the data acquisition for element-specific parameters at the site, with considering the variation of radiation dose by combining the significant element-specific parameters. As a result, we identified the availability of the existing generic biosphere dataset and the priority on data acquisition of the element-specific parameters of key radionuclides in the safety assessment of geological disposal that should be acquired at the site. This priority list would be useful for effective data acquisition at the site.

Journal Articles

A Systematic approach to evaluate the importance of concerns affecting the geological disposal of radioactive wastes

Oi, Takao; Inagaki, Manabu; Kawamura, Makoto; Ebashi, Takeshi

Materials Research Society Symposium Proceedings, Vol.1124, p.407 - 412, 2009/00

In the safety assessment of geological disposal system of radioactive waste, diverse apprehensions have been extracted from the viewpoint of the impact on the safety and the researches relating to those have been carried out strenuously. However, systematical investigation for presenting the relative importance of those has so far scarcely been conducted. The demonstration of the importance is critical issue to contribute the improvement of reliability of safety assessment. In this study, the following investigations were carried out with the goal of developing the systematic approach which can present the relative importance of the apprehensions: (1) Establishment of Total Assessment Work Frame [TAWF], (2) Establishment of the organaization procedure for evaluating the relative importance.

Journal Articles

Application of the comprehensive sensitivity analysis method to a Korean geological disposal concept

Ebashi, Takeshi; Hwang, Y.-S.*; Lee, Y.-M.*; Oi, Takao; Koo, Shigeru*

Journal of Nuclear Science and Technology, 45(11), p.1138 - 1149, 2008/11

 Times Cited Count:11 Percentile:59.25(Nuclear Science & Technology)

In this study, as a part of the joint research between JAEA and KAERI, the comprehensive sensitivity analysis method developed by JAEA was applied to a Korean HLW disposal concept that spent fuel will be directly disposed in a rock. The purpose of this study was to confirm whether the threshold values of near-filed parameters yielding a "successful condition" where maximum dose does not exceed a target value can be extracted with regard to direct disposal concept of spent fuel. As a result, the successful conditions composed of near-field parameters were illustrated under different conservative conditions of the natural barrier. In conclusion, the comprehensive sensitivity analysis method can be applied to extraction of a successful condition composed of near-field parameters for direct disposal concept of spent fuel. Such an approach will provide useful information for scenario analysis and offer insights into construction of a robust system for direct disposal concept of spent fuel.

83 (Records 1-20 displayed on this page)