Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 25

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

Application of data assimilation in groundwater hydrology; Characterization of hydraulic heterogeneity of hydrogeological structure based on in-situ data

Onoe, Hironori

Keisan Kogaku, 24(1), p.3851 - 3854, 2019/01

In this study, inverse analysis using observed data of pumping test was carried for confirmation of the applicability of inverse analysis method of groundwater flow based on in-situ data. Target of this inverse analysis was spatial distribution of hydrogeological heterogeneity of the fault. Inverse analysis had been applied to the area around the Mizunami Underground Research Laboratory, which is constructed by the Japan Atomic Energy Agency in order to construct scientific and technological basis for geological disposal of High-level Radioactive Waste. As a result of this study, the estimated results of inverse analysis are consistent with previous study result, and it was concluded that inverse analysis using hydraulic response due to pumping test is effective for hydrogeological characterization in deep underground.

JAEA Reports

Study on modeling and analysis of groundwater flow with inverse analysis, 2 (Joint research)

Onoe, Hironori; Yamamoto, Shinya*; Kohashi, Akio; Ozaki, Yusuke; Sakurai, Hideyuki*; Masumoto, Kiyoshi*

JAEA-Research 2018-003, 84 Pages, 2018/06

JAEA-Research-2018-003.pdf:17.44MB

In this study, numerical experiments considered hydrogeological structures, which has high heterogeneity around the Mizunami Underground Research Laboratory and inverse analysis using in-situ data were carried out. The results showed that concentration of hydrogeological structure to be estimated and location of monitoring point is important for application of inverse analysis. Furthermore, it is concluded that inverse analysis using hydraulic response due to pumping test is effective for hydrogeological characterization.

Journal Articles

Development of a back analysis method for the estimation of in situ stress based on the measured convergence in the Horonobe Underground Research Laboratory

Aoyagi, Kazuhei; Kamemura, Katsumi*; Nago, Makito*; Sugawara, Kentaro*; Matsubara, Makoto*

Proceedings of ITA-AITES World Tunnel Congress 2017 (WTC 2017) (USB Flash Drive), 10 Pages, 2017/06

An in situ stress state is one of the important factors in the design of deep underground facility of high-level radioactive waste disposal repository. This study establishes a practical and effective method for estimating in situ stress state on the basis of the measured convergence during gallery excavation. The convergence was measured in various directions of the loop gallery at 350m depth of the Horonobe Underground Research Laboratory; this allows determination of the stress state corresponding to the rock mass deformation behavior in an approximately 120 m* 200 m area. To estimate in situ stress state around that area, a back analysis method considering the existence of faults and fractures around the gallery was developed. The analyzed results showed a good agreement with the trend of in situ stress state estimated from hydraulic fracturing method.

JAEA Reports

Study on modeling and analysis of groundwater flow with inverse analysis (Joint research)

Kohashi, Akio; Onoe, Hironori; Yamamoto, Shinya*; Honda, Makoto*; Sakurai, Hideyuki*; Masumoto, Kiyoshi*

JAEA-Research 2015-022, 89 Pages, 2016/03

JAEA-Research-2015-022.pdf:27.85MB

In Japan, high-level radioactive waste (HLW) will be emplaced in a stable host rock formation deeper than 300 meters underground for geological disposal. It is important to understand heterogeneous distribution of hydraulic conductivity from the viewpoints of the safety assessment of geological disposal of HLW and construction of underground facilities. Inverse analysis based on the transient data is an efficient technique for estimating the heterogeneous distribution. In this study, numerical experiments with the adjoint state method and the ensemble Kalman filter were carried out in order to understand effective method for application of these inverse analysis. As a result of this study, the capability of each analysis techniques was shown.

Journal Articles

Evaluation of mechanical properties and microstructure in ion-irradiated surface layer

Naoe, Takashi*; Futakawa, Masatoshi; Naito, Akira*; Kogawa, Hiroyuki; Ikeda, Yujiro; Motohashi, Yoshinobu*

JSME International Journal, Series A, 48(4), p.280 - 285, 2005/10

Target vessel materials used in spallation neutron source will be exposed to proton and neutron irradiation and mercury immersion environments. In order to evaluate the surface degradation of the vessel candidate materials due to such environment, the triple-ion beam irradiation taking the spallation reaction into account and mercury immersion tests were carried out. Mechanical properties of the gradient surface layer ware evaluated by the inverse analysis with multi-layer model that considers distribution of surface characteristic was applied to the load and depth curves measured by using the instrumented indentation machine. Transmission electron microscopic observations ware performed to evaluate the changes of microstructure in irradiated surface layer using focused ion-beam cut micro-specimen. It was confirmed that the ductility loss is enhanced by the irradiation and mercury immersion, and simulated stress and strain curves of the ion-irradiated surface layer ware adequately in good agreement with the curves of experimental equivalent neutron-irradiated material.

Journal Articles

Mechanical property evaluation of gradient surface layer by inverse analysis using spherical-contact multi layer model

Naoe, Takashi*; Futakawa, Masatoshi; Naito, Akira*; Ioka, Ikuo; Kogawa, Hiroyuki

Jikken Rikigaku, 5(1), p.15 - 21, 2005/03

no abstracts in English

Journal Articles

Mechanical characterization of austenitic stainless steel ion irradiated under external stress

Ioka, Ikuo; Futakawa, Masatoshi; Naito, Akira; Nanjo, Yoshiyasu*; Kiuchi, Kiyoshi; Naoe, Takashi*

Journal of Nuclear Materials, 329-333(Part2), p.1142 - 1146, 2004/08

 Times Cited Count:0 Percentile:100(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

Mechanical property evaluation of surface layer corroded in thermochemical-hydrogen-production process condition

Futakawa, Masatoshi; Kubo, Shinji; Wakui, Takashi*; Onuki, Kaoru; Shimizu, Saburo; Yamaguchi, Akihisa*

Jikken Rikigaku, 3(2), p.109 - 114, 2003/06

Micro-indentation technique was applied to evaluate the mechanical properties of corroded surface layers of Ni-alloy, 316SS, Ti and Ta, which were exposed into the corrosive gaseous environment consisting of HI+I$$_{2}$$+H$$_{2}$$O+H$$_{2}$$. The corrosion condition was chosen so as to simulate one of the environments in the thermochemical hydrogen production, IS process, where the degradation due to the corrosion attack by HI and the hydrogen embrittlement is a key issue from the viewpoint of material integrity. The micro-indentation tests using a spherical indenter and the inverse analysis with Kalman filter were performed to quantitatively estimate material constants of corroded surface layer. Ni-alloy exhibited good corrosion resistance and Ta was remarkably influenced by the hydrogen embrittlement.

Journal Articles

Mechanical property evaluation of stressed microscale zone by indentation technique

Naoe, Takashi*; Futakawa, Masatoshi; Wakui, Takashi*; Kogawa, Hiroyuki

Nippon Kikai Gakkai Kanto Shibu Ibaraki Koenkai (2002) Koen Rombunshu, p.3 - 4, 2002/09

no abstracts in English

Journal Articles

Relationship between tensile curve and indentation load-depth curve for a Ni-base alloy with microstructures by cold work and aging

Yamamoto, Junichiro*; Futakawa, Masatoshi; Kurata, Yuji; Naoe, Takashi*

Nippon Kikai Gakkai Kanto Shibu Ibaraki Koenkai (2002) Koen Rombunshu, p.1 - 2, 2002/09

no abstracts in English

JAEA Reports

None

*;

JNC-TY7400 2000-004, 62 Pages, 2000/05

JNC-TY7400-2000-004.pdf:1.45MB

None

JAEA Reports

Enhancement of Nondestructive Evaluation Technique for Magnetic and Nonmagnetic Structural Components

JNC-TN9400 2000-021, 104 Pages, 2000/03

JNC-TN9400-2000-021.pdf:5.21MB

ln this report, research works performed in the Structura1 Safety Engineering Group of OEC/JNC are summarized as the final report of the doctoral fellowship. The main objective of this study is for the enhancement of the nondestructive evaluation techniques for structural components of both magnetic and nonmagnetic material. Studies in three topics have been carried out aiming at the quantitative evaluation of crack with the eddy current testing and the validation of a natural magnetic field based NDE method for detecting mechanical damages in a paramagnetic material. ln the first part of the study, an approach to the reconstruction of the natural crack was proposed and implemented with an idealized crack model for its validation. ln the second part, the correlation of the natural magnetization and the mechanical damages in the SUS304 stainless steel was investigated by using an experimental approach. ln part 3, an inverse method of the measured magnetic fields is proposed for the reconstruction of magnetic charges in the inspected material by using an optimization method and wavalet. As the first work, an approach to the reconstruction of an idealized natural crack of non-vanishing conductivity is proposed with use of signals of eddy current testing. Two numerical models are introduced at first for modeling the natural crack in order to represented it with a set of crack parameters. A method for the rapid prediction of the eddy current testing signals coming from these idealized cracks is given then by extending a knowledge based fast forward solver to the case of a non-vanishing conductivity. Based on this fast forward solver, the inverse algorithm of conjugate gradient method is updated to identify the crack parameters. Several examples are presented finally as a validation of the proposed strategy. The results show that both the two numerical models can give reasonable reconstruction results for signal of low noise. The model concerning the touch of ...

Oral presentation

Inverse analysis methods for characterization of hydrogeological heterogeneity, 1; Numerical experiments with adjoint state method

Masumoto, Kiyoshi*; Onoe, Hironori; Kohashi, Akio; Yamamoto, Shinya*

no journal, , 

no abstracts in English

Oral presentation

Inverse analysis methods for characterization of hydrogeological heterogeneity, 2; Numerical experiments with ensemble Kalman filter

Yamamoto, Shinya*; Honda, Makoto*; Sakurai, Hideyuki*; Onoe, Hironori; Masumoto, Kiyoshi*

no journal, , 

no abstracts in English

Oral presentation

Inverse analysis methods for characterization of hydrogeological heterogeneity, 3; The Influence of analysis methodology on the estimated result

Onoe, Hironori; Yamamoto, Shinya*; Masumoto, Kiyoshi*; Kohashi, Akio; Saegusa, Hiromitsu

no journal, , 

no abstracts in English

Oral presentation

Characterization of spatial hydrogeological heterogeneity with ensemble Kalman filter

Yamamoto, Shinya*; Honda, Makoto*; Sakurai, Hideyuki*; Onoe, Hironori; Masumoto, Kiyoshi*

no journal, , 

no abstracts in English

Oral presentation

Inverse analysis methods for characterization of hydrogeological heterogeneity

Kohashi, Akio; Onoe, Hironori; Yamamoto, Shinya*; Honda, Makoto*; Sakurai, Hideyuki*; Masumoto, Kiyoshi*

no journal, , 

no abstracts in English

Oral presentation

Estimation of hydraulic conductivity in fault zone by inversion of water head data

Ozaki, Yusuke; Kohashi, Akio; Onoe, Hironori; Yamamoto, Shinya*; Masumoto, Kiyoshi*

no journal, , 

The objective of this study is verification of feasibility to estimate hydraulic conductivity with inversion method of water head data in fault zone. Hydraulic conductivity in a fault zone is focused on as a target of inversion because the fault would significantly affect a water head field. A series of numerical test with synthetic model is performed under the condition that the number of fault to estimate hydraulic conductivity and the degree of freedom of hydraulic conductivity distribution in a fault zone is different. The information of hydraulic conductivity outside the faults and location of fault is given to the inversion a priori. Our inversion results shows that the accuracy of estimation is improved by constrain to the number of fault to estimate the hydraulic conductivity and freedom of hydraulic conductivity distribution in a fault. In addition, the number of fault to estimate the hydraulic conductivity should be limited for the certain estimation of hydraulic conductivity in all faults.

Oral presentation

A Study of multi-inverse analysis for modeling of hydrogeological heterogeneity of the rock mass

Suemitsu, Akinobu*; Masumoto, Kiyoshi*; Onoe, Hironori

no journal, , 

no abstracts in English

25 (Records 1-20 displayed on this page)