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Journal Articles

Neutron capture and total cross-section measurements and resonance parameter analysis of niobium-93 below 400 eV

Endo, Shunsuke; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Osamu; Iwamoto, Nobuyuki; Rovira Leveroni, G.; Terada, Kazushi*; Meigo, Shinichiro; Toh, Yosuke; Segawa, Mariko; et al.

Journal of Nuclear Science and Technology, 59(3), p.318 - 333, 2022/03

Journal Articles

Nondestructive quantitative analysis of difficult-to-measure radionuclides $$^{107}$$Pd and $$^{99}$$Tc

Toh, Yosuke; Segawa, Mariko; Maeda, Makoto; Tsuneyama, Masayuki*; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Ebihara, Mitsuru*

Analytical Chemistry, 93(28), p.9771 - 9777, 2021/07

Journal Articles

Development on computer system of the coupled thermo-hydro-mechanical and chemical process in the near-field of the high-level radioactive waste repository

Fujita, Tomo; Fujisaki, Kiyoshi; Suzuki, Hideaki*; Kawakami, Susumu; Yui, Mikazu; Chijimatsu, Masakazu*; Neyama, Atsushi*; Ishihara, Yoshinao*; Hishiya, Tomoyuki*

Proceedings of 2nd International Conference on Coupled T-H-M-C Processes in Geo-systems; Fundamentals, Modeling, Experiments and Applications (GeoProc 2006), p.416 - 421, 2006/00

We have initiated a research on the coupled Thermo-Hydro-Mechanical-Chemical (THMC) processes and are trying to carry out numerical experiments on the coupled THMC processes in order to predict the near-field long-term evolution. This paper describes the modified THMC model to add on the function of de-gases and gases diffusion, accumulation and dilution phenomena for mass transport analysis, and of ionic exchange, surface reaction and kinetic reaction for geochemical analysis. And also the results of demonstration study with THMC code are shown.

JAEA Reports

Development of the JNC Geological Disposal Technical Information Integration System Subjected for Repository Design and Safety Assessment -Document on Present State of Affairs-

Ishihara, Yoshinao*; Ito, Takashi*; Kobayashi, Shigeki*; Neyama, Atsushi*

JNC TJ8440 2004-005, 137 Pages, 2004/02

JNC-TJ8440-2004-005.pdf:2.42MB

On this work, system manufacture about disposal technology and safety assessment field was performed towards construction of the JNC Geological Disposal Technical Information Integration System which systematized three fields of technical information acquired in investigation (site characteristic investigation) of geology environmental conditions, disposal technology (design of deep repository), and performance/safety assessment.The technical information database managed focusing on the technical information concerning individual research of an examination, analysis, etc. and the parameter set database managed focusing on the set up data set used in case of comprehensive evaluation are examined.In order to support and promote share and use of the technical information registered and managed by the database, utility functions, such as a technical information registration function, technical information search / browse function, analysis support function, and visualization function, are considered, and the system realized in these functions is built.The built system is installed in the server of JNC, and the functional check examination is carried out.

JAEA Reports

Study on Radiation Dose from Vitrified Waste

WAKASUGI, Keiichiro; Miyahara, Kaname; Makino, Hitoshi; Ishiguro, Katsuhiko; Sawamura, Hidenori*; Neyama, Atsushi*; Nishimura, Kazuya*

JNC TN8400 2003-022, 84 Pages, 2003/11

JNC-TN8400-2003-022.pdf:9.58MB

The radiation dose from the vitrified waste which is the same specification set in the Reference Case of the second progress report (H12 report) was evaluated quantitatively taking into account of the shield of the canister and the overpack. In order to understand the feature of radiation dose from the vitrified waste in terms of shielding, the thickness of the concrete shield to decrease less than safety standard for a radiation controlled zone was evaluated. Main results are summarized as follows. (1)The effective dose rates in the case considering the vitrified waste and the canister decrease approximate 4$$sim$$5 orders of magnitude during the period of 1,000 years after vitrification due to decay of short half-life radionuclides. The effective dose rate doesn't decrease from 1,000 to 10,000 years. (2)The effective dose rates at the outside of overpack in the case considering the vitrified waste, canister and overpack are smaller than those inside of overpack approximate 5 orders of magnitude during the period of 100 years due to shielding effect of the overpack. However this difference is relatively small after 100 years since the contribution of $$gamma$$ radiation to total effective dose rates decrease due to decay of fission products. (3)Excepting a few cases, the result using the old law (dose equivalent rate) is larger than the result using the new law (effective dose rate). However the difference between these results is less than factor of 1.2. (4)The thickness of the concrete shield required to attenuate the effective dose during the period of 50 years less than safety standard for a radiation controlled zone is calculated as approximate 0.8m$$sim$$1.5m. The important factors to determine the thickness of the concrete shield are the $$gamma$$ radiation in the case of vitrified waste and the canister, and the neutron radiation in the case of vitrified waste, canister and overpack.

JAEA Reports

The Computational Design of Geological Disposal Technology Integration Syatem(II)

Ishihara, Yoshinao*; Neyama, Atsushi*; Kobayashi, Shigeki*; Iwamoto, Hiroshi*

JNC TJ8440 2003-006, 250 Pages, 2003/02

JNC-TJ8440-2003-006.pdf:4.06MB

In order to develop "Geological Disposal Technology Integration System" that is intended to systematize as knowledge base for fundamental study of geologixal environment, repository design and safety assessment, the computational design of an indispensable database and main function of "Geolodical Disposal Technology Integrated System" was done. The prototype was made in order to verify the system function.

JAEA Reports

Investigation Research on the Evaluation of a Coupled Thermo-Hydro-Mechanical-Chemical Phenomena (II); Outline Report

Ishihara, Yoshinao*; Chijimatsu, Masakazu*; Neyama, Atsushi*; Tanaka, Yumiko*; Amemiya, Kiyoshi*; Shiozaki, Isao*; Ito, Takaya*

JNC TJ8400 2003-033, 118 Pages, 2003/02

JNC-TJ8400-2003-033.pdf:1.66MB

In order to realize a coupling analysis in the near field of the geological disposal system, the coupling analysis code on the thermo-hydro-mechanical-chemical phenomena by THAMES, Dtransu and phreeqe60, which are existing analysis code, is developed in this study. And we carried out the case analysis on the thermo-hydro-mechanical-chemical phenomena by this code.

JAEA Reports

Investigation Research on the Evaluation of a Coupled Thermo-Hydro-Mechanical-Chemical Phenomena (II) - Result Report-

Ishihara, Yoshinao*; Chijimatsu, Masakazu*; Neyama, Atsushi*; Tanaka, Yumiko*; Amemiya, Kiyoshi*; Shiozaki, Isao*; Ito, Takaya*

JNC TJ8400 2003-032, 237 Pages, 2003/02

JNC-TJ8400-2003-032.pdf:2.5MB

In order to realize a coupling analysis in the near field of the geological disposal system, the coupling analysis code on the thermo-hydro-mechanical-chemical phenomena by THAMES, Dtransu and phreeqe60, which are existing analysis code, is developed in this study. And we carried out the case analysis on the thermo-hydro-mechanical-chemical phenomena by this code.

JAEA Reports

None

Ishihara, Yoshinao*; *; *; Neyama, Atsushi*; *; *

JNC TJ8440 2002-009, 179 Pages, 2002/03

JNC-TJ8440-2002-009.pdf:3.03MB

no abstracts in English

JAEA Reports

Evaluation of Irradiation Field of High-Level Radioactive Waste

Sawamura, Hidenori*; Neyama, Atsushi*; Nishimura, Kazuya*

JNC TJ1400 2003-003, 300 Pages, 2002/03

JNC-TJ1400-2003-003.pdf:4.83MB

None

JAEA Reports

Investigation research on the evaluation of a coupled thermo-hydro-mechanical-chemical phenomena; outline report

Chijimatsu, Masakazu*; Neyama, Atsushi*; Ishihara, Yoshinao*; Amemiya, Kiyoshi*; *; Iwata, Hiroshi*; Sagawa, Hiroshi*

JNC TJ8400 2002-004, 83 Pages, 2002/02

JNC-TJ8400-2002-004.pdf:0.91MB

In order to realize a coupling analysis in the near field of the geological disposal system, this study has been studied on the addition of the mass transport model to the coupled thermo-hydro-mechanical analysis code (THAMES) and preliminary coupling analysis by using development environmental tool (Diffpack) for numerical analysis. (1) In order to prepare the strategy on the addition of the mass transport model to the coupled thermo-hydro-mechanical analysis code (THAMES), we have studied on the requirement of THAMES-Transport and methodology of coupling analysis. After that we set out modification plan by the Eulerian-Lagrangian (EL) method. (2) Based on the document of modification plan, we have done addition of the mass transport model to the coupled thermo-hydro-mechanical analysis code (THAMES) and carried out verification analysis in order to confirm on the accuracy of THAMES-Transport. (3) In order to understand on the behavior of NaCl in the porewater under the coupled thermo-hydro-mechanical phenomena in the HLW engineered barrier system, we have calculated coupling phenomenon by using THAMES-Transport. Transportation and concentration phenomena of NaCl are calculated but precipitation of NaCl is not occurred under the analysis conditions in this report. (4) In order to confirm about feasibility of coupling analysis under the development environmental tool (Diffpack) for numerical analysis, we have carried out on the design work and writing program of the preliminary coupling system. In this study, we have adopted existing transport model (HYDROGEOCHEM) and geochemical model (phreeqe60) for preliminary coupling system. (5) In order to confirm program correctness of preliminary coupling system, we have carried out benchmarking analysis by using existing reactive-transport analysiscode (HYDROGEOCHEM). (6)We have been prepared short-range development plan based on through the modification study of THAMES and writing program of the preliminary coupling ...

JAEA Reports

Investigation research on the evaluation of a coupled thermo-hydro-mechanical-chemical phenomena; result report

Chijimatsu, Masakazu*; Neyama, Atsushi*; Ishihara, Yoshinao*; Amemiya, Kiyoshi*; *; Iwata, Hiroshi*

JNC TJ8400 2002-003, 155 Pages, 2002/02

JNC-TJ8400-2002-003.pdf:1.51MB

In order to realize a coupling analysis in the near field of the geological disposal system, this study has been studied on the addition of the mass transport model to the coupled thermo-hydro-mechanical analysis code (THAMES) and preliminary coupling analysis by using development environmental tool (Diffpack) for numerical analysis. (1)In order to prepare the strategy on the addition of the mass transport model to the coupled thermo-hydro-mechanical analysis code (THAMES), we have studied on the requirement of THAMES-Transport and methodology of coupling analysis. After that we set out modification plan by the Eulerian-Lagrangian (EL) method. (2)Based on the document of modification plan, we have done addition of the mass transport model to the coupled thermo-hydro-mechanical analysis code (THAMES) and carried out verification analysis in order to confirm on the accuracy of THAMES-Transport. (3)In order to understand on the behavior of NaCl in the porewater under the coupled thermo-hydro-mechanical phenomena in the HLW engineered barrier system, we have calculated coupling phenomenon by using THAMES-Transport. Transportation and concentration phenomena of NaCl are calculated but precipitation of NaCl is not occurred under the analysis conditions in this report. (4)In order to confirm about feasibility of coupling analysis under the development environmental tool (Diffpack) for numerical analysis, we have carried out on the design work and writing program of the preliminary coupling system. In this study, we have adopted existing transport model (HYDROGEOCHEM) and geochemical model (phreeqe60) for preliminary coupling system. (5)In order to confirm program correctness of preliminary coupling system, we have carried out benchmarking analysis by using existing reactive-transport analysiscode (HYDROGEOCHEM). (6)We have been prepared short-range development plan based on through the modification study of THAMES and writing program of the preliminary coupling ...

JAEA Reports

Investigation research of core-basic information associated with the coupling analysis; Outline report

Kataoka, Shinichi*; Kawahara, Kenichi*; Matsunaga, Kenichi*; Ishihara, Yoshinao*; Neyama, Atsushi*; Nakagawa, Koichi*; Iwata, Hiroshi*; Mori, Koji*

JNC TJ8400 2001-037, 33 Pages, 2001/03

JNC-TJ8400-2001-037.pdf:2.02MB

no abstracts in English

JAEA Reports

Investigation research of core-basic information associated with the coupling analysis; result report

Kataoka, Shinichi*; Kawahara, Kenichi*; Matsunaga, Kenichi*; Ishihara, Yoshinao*; Neyama, Atsushi*; Nakagawa, Koichi*; Iwata, Hiroshi*

JNC TJ8400 2001-036, 202 Pages, 2001/03

JNC-TJ8400-2001-036.pdf:7.58MB

The newest literature information in the foreign countries was researched, and this research showed the basic concept of the coupling analysis code to realize coupling analysis in near field of the geological disposal system. The outline of this research is shown in the following. (1)The combination of M (Mechanical) and (Chemistry) is placed on the weak relations, Because coupling analysis of the United States Yucca Mountain limits a site and the specifications of engineered barrier. (2)One of the purposes of this research is information collecting about coupling analysis code NUFT-C adopted in the United States Yucca Mountain. Therefore, we carried out an information exchange with the United States Lawrence Livermore National Laboratory. We could collect the development purpose of analysis code, key function, and information such as a test case analysis. (3)The investigation of the analysis code concerned with the newest information of coupling analysis which contains the geochemistry process and 2 phase system was done based on the public information for the purpose of building some concept of the coupling analysis code, the extraction of the development issues. It could be understood about the future development strategy and the precaution in addition to a phenomenon to deal with, the current status of the coupling analysis technique as a result of the investigation. (4)It was cleared about the mission of the coupling analysis code and the requirement items (function, quality) by this research. Then, some development options were presented. (5)It was studied about the procedure of developing it to satisfy the above requirement toward the conditions that a site isn't selected, the short development. The tool (Diffpack) which could cope with the speed-up of the calculation time and visualization flexibly was effective, and it was summarized about the test case by using this tool, the key function of this tool as that result.

JAEA Reports

Development of the evaluation methodology for earthquake resistance of the engineered barrier system (III)

Mori, Koji*; Neyama, Atsushi*; Nakagawa, Koichi*

JNC TJ8400 2000-064, 175 Pages, 2000/03

JNC-TJ8400-2000-064.pdf:5.23MB

In this study, the following tasks have been performed in order to evaluate the stability of earthquake resistance for the engineered barrier system(EBS) of High Level Waste (HLW) geological isolation system. (1)validation studies for the liquefaction model. The function of single-phase analysis without interaction between soil and pore water in three-dimensional effective stress analysis code, which had been developed in this study, have been verified using by actual vibration test data. This fiscal year, some validation studies for the function of liquefaction analysis was conducted usig by actual measured data through the laboratory liquefaction test. (2)Supplemental Studies for JNC Second Progress Report. Through the JNC second progress report, it was considered that the stability of earthquake resistance of the engineered barrier system would be maintained under the major seismic event. At the same time we have recognized that several model parameters for joint-crack element, which takes into account for the response behavior of material discontinuous surface such as between overpack and buffer material, will become important in the response behavior of the whole EBS. This year, we have studied about several topics, which arise from technical discussion on JNC second progress report and we have discussed about total seismic stability of EBS. (3)Supplemental Studies for joint study with NRIDP. At this fiscal year, the joint study with National Research Institute for Disaster Prevention (NRIDP) will be final stage. UP to this day, incremental validation studies had been continued using by mesuared data obtained from vibration test. In this final stage, validation analysis has been conducted again using by current version new analysis code and maintained the validation data which will be contribute to the joint study mentioned above.

JAEA Reports

Study on solubility and leaching property of iodine-129 waste-forms for geological disposal

Yanagisawa, Ichiro*; Katsurai, Kiyomichi*; Izumi, Jun*; Saigusa, Moriyuki*; Kitao, Hideo*; Tsuzuki, Yasuo*; Neyama, Atsushi*; Kato, Hiroyasu*; Nakazawa, Toshiyuki*; Okada, Kenichi*

JNC TJ8400 2000-037, 61 Pages, 2000/02

JNC-TJ8400-2000-037.pdf:2.78MB

no abstracts in English

JAEA Reports

Development of Thermodynamic Databases for Geochemical Calculations

Oda, Chie; Arthur, R. C,*; Sasamoto, Hiroshi; Shibata, Masahiro; Yui, Mikazu; Neyama, Atsushi*

JNC TN8400 99-079, 287 Pages, 1999/09

JNC-TN8400-99-079.pdf:9.78MB

Two thermodynamic databases for geochemical calculations supporting research and development on geological disposal concepts for high level radioactive waste are described in this report. One, SPRONS.JNC, is compatible with thermodynamic relations comprising the SUPCRT model and software, which permits calculation of the standard molal and partial molal thermodynamic properties of minerals, gases, aqueous species and reactions from 1 to 5000 bars and 0 to 1000$$^{circ}$$C. This database includes standard molal Gibbs free energies and enthalpies of formation, standard molal entropies and volumes, and Maier-Kelly heat capacity coefficients at the reference pressure (1 bar) and temperature (25$$^{circ}$$C) for 195 minerals and 16 gases. It also includes standard partial molal Gibbs free energies and enthalpies of formation, standard partial molal entropies, and Helgeson, Kirkham and Flowers (HKF) equation-of-state coefficients at the reference pressure and temperature for 1147 inorganic and organic aqueous ions and complexes. SPRONS.JNC extends similar databases described elsewhere by incorporating new and revised data published in the peer-reviewed literature since 1991. The other database, PHREEQE.JNC, is compatible with the PHREEQE series of geochemical modeling codes. It includes equilibrium constants at 25$$^{circ}$$C and 1 bar for mineral-dissolution, gas-solubility, aqueous-association and oxidation-reduction reactions. Reaction enthalpies, or coefficients in an empirical log K(T) function, are also included in this database, which permits calculation of equilibrium constants between 0 and 100$$^{circ}$$C at 1 bar. All equilibrium constants, reaction enthalpies, and logK(T) coefficients in PHREEQE.JNC are calculated usig SUPCRT and SPRONS.JNC, which ensures that these two databases are mutually consistent. They are also internally consistent insofar as all the data are compatible with basic thermodynamic definitions and functional relations in the SUPCRT ...

JAEA Reports

Development of the evaluation methodology for earthquake resistance of the engineered barrier system(II)

Mori, Koji*; Neyama, Atsushi*; Shirakawa, Toshihiko*

JNC TJ8400 99-080, 149 Pages, 1999/02

JNC-TJ8400-99-080.pdf:10.38MB

In this study, the following several tasks have been performed in order to evaluate the stability of earthquake resistance for the engineered barrier system of High Level Waste(HLW) geological isolation system. (1)Based on the wave propagation theory for one-dimensional multi-layer system, we have estimated the underground seismic wave that propagates in the HLW repository site. This analysis was based upon the JNC Virtual Geological Model and we used the E1-Centro earthquake data as the surface observed wave. Through this inversion analysis, we have found that this interest geological model has the about 60%(G.L.-1000m) and 20%(G.L.-500m) decreasing ratio of the acceleration to the surface observed acceleration level. (2)Since 1992 we have developed the three dimensional seismic response analysis code for the engineered barrier system, which based on Finite Element Methodology. This analysis code has various function to take into consideration ae realistic repository system(e.g. material nonlinear models, joint crack element and infinite viscous boundary element). We have made the study of the concrete analysis method designed to the near field seismic response analysis, through the sensitivity analysis using above various function. Based on these studies, we have evaluated the earthquake resistance stability for the near-field repository system. Two types of disposal concept were considered as the reference case associated with the JNC second progress report. Through this study, we have concluded that the shear stress due to earthquake in the buffer material is very small relative to that due to the earth load and the earthquake resistance stability will be maintained.

JAEA Reports

Development of the evaluation methodology for earthquake resistance of the engineered barrier system, II

Mori, Koji*; Neyama, Atsushi*; Shirakawa, Toshihiko*

JNC TJ8400 99-079, 32 Pages, 1999/02

JNC-TJ8400-99-079.pdf:3.51MB

In this study, the following several tasks have been performed in order to evaluate the stability of earthquake resistance for the engineered barrier system of High Level Waste(HLW) geological isolation system. (1)Based on the wave propagation theory for one-dimensional multl-layer system, we have estimated the underground seismic wave that propagates in the HLW repository site. This analysis was based upon the JNC Virtual Geological Model and we used the El-Centro earthquake data as the surface observed wave. Through this inversion analysis, we have found that this interest geological model has the about 60%(G.L.-1000m) and 20%(G.L.-500m) decreasing ratio of the acceleration to the surface observed acceleration level. (2)Since 1992 we have developed the three dimensional seismic response analysis code for the engineered barrier system, which based on Finite Element Methodology. This analysis code has various function to take into consideration the realistic repository system(e.g.material nonlinear models, joint crack element and infinite viscous boundary element). We have made the study of the concrete analysis method designed to the near field seismic response analysis, through the sensitivity analysis using above various function. Based on these studies, we have evaluated the earthquake resistance stability for the near-field repository system. Two types of disposal concept were considered as the reference case associated with the JNC second progress report. Through this study, we have concluded that the shear stress due to earthquake in the buffer material is very small relative to that due to the earth load and the earthquake resistance stability will be maintained.

JAEA Reports

None

Mori, Koji*; Neyama, Atsushi*; *; Nishimura, Kazuya*

PNC TJ1458 97-004, 26 Pages, 1997/02

PNC-TJ1458-97-004.pdf:0.88MB

None

40 (Records 1-20 displayed on this page)