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Nishiyama, Nariaki; Kawamura, Makoto; Umeda, Koji*; Niwa, Masakazu
Oyo Chishitsu, 64(3), p.98 - 111, 2023/08
It is important to accumulate research examples on the spatial distribution of dikes under volcanic edifices for risk assessment in volcanic disaster prevention and site selection and safety assessment for the geological disposal of high-level radioactive waste. The topography of volcanoes is considered to represent the location of magma intrusion associated with volcanic activity and its history. In this study, we attempted to determine the predominant orientation of radial dikes and evaluate the central conduit stability based on the distribution, centroid, and area of contour lines comprising the volcanic edifices using GIS-based topographic analysis. As a result of the topographic analysis, the predominant orientation of the dikes was successfully shown for the volcanoes with stable conduits. On the other hand, this analysis was not suitable for determine the predominant orientation of dikes in volcanoes with unstable conduits, thus the applicable range of this analysis is considered to be determined by the conduit stability. In addition, the conduit stability can be evaluated by using the area data of contour polygons, which represents the scope of application to the method for determination of the predominant orientation of dikes. This means that the conduit stability during volcanic activity can be evaluated even for volcanoes of which activity history is not yet known, and that topographic analysis is a useful tool for this purpose. The use of topographic analysis in this study will be expected to provide a new scale for the history of volcanic activity.
Nishiyama, Nariaki; Goto, Akira*; Tsukahara, Yuzuko; Kawamura, Makoto; Umeda, Koji*; Niwa, Masakazu
JAEA-Testing 2022-003, 51 Pages, 2022/09
JAEA-Testing-2022-003.pdf:5.24MB
JAEA-Testing-2022-003-appendix(CD-ROM).zip:1.12MB
Advancement of the evaluation technology of the magma activity range is essential as one of the technical issues related to volcanic and igneous activities in the evaluation of the long-term stability of the geological environment in the geological disposal of high-level radioactive waste. As an effective method, topographical analysis of volcanic edifices is expected to be used to determine the distribution area of dikes. In recent years, the development of computer-based topographic analysis technology has made it possible to simply perform a large volume of work that would otherwise be difficult due to the manual handling. This report describes an analysis method for the shape of contour lines that forms volcanic edifices using GIS software.
Tobita, Toru; Nishiyama, Yutaka; Otsu, Takuyo; Udagawa, Makoto; Katsuyama, Jinya; Onizawa, Kunio
Journal of Pressure Vessel Technology, 137(5), p.051405_1 - 051405_8, 2015/10
Times Cited Count：14 Percentile：56.3(Engineering, Mechanical)We conducted a series of fracture toughness tests based on the Master curve method for several specimen size and shapes, such as 0.16T-CT, pre-cracked Charpy type, 0.4T-CT and 1T-CT specimens, in commercially manufactured 5 kinds of A533B class1 steels with different impurity contents and fracture toughness levels. The reference temperature (
) values determined from the 0.16T-CT specimens were overall in good agreement with those determined from the 1T-CT specimens. The scatter of the 1T-equivalent fracture toughness values obtained from the 0.16T-CT specimens was equivalent to that obtained from the other larger specimens. The higher loading rate gave rise to a slightly higher , and this dependency was almost the same for the larger specimens. We suggested an optimum test temperature on the basis of the Charpy transition temperature for determining using the 0.16T-CT specimens.
Tobita, Toru; Udagawa, Makoto; Chimi, Yasuhiro; Nishiyama, Yutaka; Onizawa, Kunio
Journal of Nuclear Materials, 452(1-3), p.61 - 68, 2014/09
Times Cited Count：9 Percentile：58.71(Materials Science, Multidisciplinary)To investigate the changes in the mechanical properties of cladding materials irradiated with high neutron fluence, two types of cladding materials were fabricated using the submerged-arc welding and electroslag welding methods. The tensile tests, Charpy impact tests and fracture toughness tests were conducted before and after neutron irradiation with a fluence of 10
n/cm
at 290 
C. With neutron irradiation, the yield strength and ultimate strength increased, and the total elongation decreased. The Charpy upper-shelf energy was reduced and the ductile-to-brittle transition temperature was increased with neutron irradiation. There was no obvious decrease in the elastic-plastic fracture toughness (J
) of the cladding materials at high neutron fluence. The tearing modulus decreased with neutron irradiation, and considerable low J values were observed at high temperatures submerged-arc-welded cladding materials.
Yamaguchi, Yoshihito; Katsuyama, Jinya; Udagawa, Makoto; Onizawa, Kunio; Nishiyama, Yutaka; Li, Y.*
Proceedings of 22nd International Conference on Nuclear Engineering (ICONE-22) (DVD-ROM), 8 Pages, 2014/07
Tobita, Toru; Nishiyama, Yutaka; Otsu, Takuyo; Udagawa, Makoto; Katsuyama, Jinya; Onizawa, Kunio
Proceedings of 2013 ASME Pressure Vessels and Piping Conference (PVP 2013) (DVD-ROM), 8 Pages, 2013/07
Mini-CT (0.16T-CT) specimens up to eight can be taken from broken halves of surveillance Charpy specimens. We conducted a series of fracture toughness tests based on the Master curve method for several specimen size and shapes, such as 0.16T-CT, pre-cracked Charpy type, 0.4T-CT and 1T-CT specimens, in commercially manufactured 5 kinds of A533B class1 steels with different impurity contents and fracture toughness levels. Reference temperature To of 0.16T-CT specimens was approximately equal to those of 1T-CT and other type of specimens for all materials. We also examined a loading rate effect on TO of Mini-CT specimens for some materials within the specified range in the test method. Higher loading rate gave rise to slightly higher TO. The difference in TO between upper and lower loading rate of the standard was approximately 10C.
Horie, Akira*; Tomita, Takeo*; Saiki, Asako*; Kono, Hidetoshi; Taka, Hikari*; Mineki, Reiko*; Fujimura, Tsutomu*; Nishiyama, Chiharu*; Kuzuyama, Tomohisa*; Nishiyama, Makoto*
Nature Chemical Biology, 5(9), p.673 - 679, 2009/09
Times Cited Count：41 Percentile：66.71(Biochemistry & Molecular Biology)Yoshida, Ayako*; Tomita, Takeo*; Kono, Hidetoshi; Fushinobu, Shinya*; Kuzuyama, Tomohisa*; Nishiyama, Makoto*
FEBS Journal, 276(11), p.3124 - 3136, 2009/06
Times Cited Count：14 Percentile：30.18(Biochemistry & Molecular Biology)Nakashima, Satoru*; Kirino, Yusuke*; Nishiyama, Naoki*; Tonoue, Ryota*; Yokoyama, Tadashi*; Nagasawa, Makoto*; Harui, Rika*; Walker, C.; Sasamoto, Hiroshi
no journal, ,
Cementitious grout material will be used to reduce groundwater inflow into the repository of high level radioactive waste. High pH solution derived from cementitious grout material may cause alteration of rock mass by grout-rock interactions. With regard to evaluation of radionuclide migration, it is important to evaluate the long-term behavior of rock mass affected by grout-rock interactions since such altered rock mass potentially affects on migration behavior (e.g., diffusion and sorption) of radionuclide. This study presents the results of identification for trace secondary minerals (alteration products) by (micro)infrared spectroscopy and determination of reaction rate constants of formation for secondary minerals.
Tobita, Toru; Nishiyama, Yutaka; Otsu, Takuyo; Udagawa, Makoto; Onizawa, Kunio
no journal, ,
no abstracts in English
Tobita, Toru; Udagawa, Makoto; Katsuyama, Jinya; Onizawa, Kunio; Nishiyama, Yutaka
no journal, ,
For safe operation of light water reactors, the structural integrity of reactor pressure vessel (RPV) is confirmed based on the evaluation and prediction of aging degradation such as irradiation embrittlement and stress corrosion cracking. To contribute to this issues, we have performed to study on the improvement of fracture toughness evaluation method and development of probabilistic fracture mechanics (PFM) analysis code for RPVs. It was clarified that temperature dependence of the fracture toughness of RPV steels with different toughness levels can be evaluated with enough accuracy using miniature specimens. In addition, in order to evaluate the failure probability of the RPV head penetration due to the PWSCC at the nickel based dissimilar metal welds, we have developed a PFM analysis code PASCAL-NP. The major findings of these studies are summarized in the poster.
Tobita, Toru; Udagawa, Makoto; Nishiyama, Yutaka; Onizawa, Kunio
no journal, ,
The neutron irradiation test was performed using stainless steel overlay cladding material of the inner surface of light water reactor pressure vessel. We report the result of elastoplastic fracture toughness test before and after irradiation. The unstable fracture did not occur at all temperature from low temperature to high temperature before and after neutron irradiation, and a ductility fracture surface was observed. Although there was few decrease in fracture toughness caused by neutron irradiation, but low fracture toughness values were observed at the high temperature range.
Katsuyama, Jinya; Nishiyama, Yutaka; Udagawa, Makoto; Yamaguchi, Yoshihito; Katsumata, Genshichiro
no journal, ,
no abstracts in English
Nishiyama, Nariaki*; Kawamura, Makoto; Umeda, Koji*; Goto, Akira; Niwa, Masakazu
no journal, ,
The authors assume that the topography of the mountain body reflects the actual distribution area of the dike, and we are developing a method to do the model the distribution area of the center conduit and radial dikes by topographical analysis of the mountain body using GIS software. In this study, we proposed a method that enables topographical analysis volcanoes whose activity history is not clear, conducted topographical analysis at each volcano, and modeled the distribution area of dikes. As a result, the analysis method used in this study made it possible to capture the features of the topography formed by the activity of the volcano without including the expert judgement. This makes it possible to compare the analysis results of this study with the geology, and this analysis results are considered to be useful information. In addition, the distribution tendency of the centroid of each altitude obtained in this study shows the results consistent with the wide-area stress field at the time of the eruption, and shows the validity of the analysis results.
Ogata, Manabu; Tsukahara, Yuzuko; Kawamura, Makoto; Kanno, Mizuho; Nishiyama, Nariaki*; Sueoka, Shigeru; Komatsu, Tetsuya; Nakanishi, Toshimichi*; Yasue, Kenichi*
no journal, ,
Optically stimulated luminescence (OSL) dating method on feldspar is useful to date sediments on geomorphological time scale. In this presentation, we present the case studies for marine terraces in the Noto Peninsula and abandoned river valleys along the Oi River, for which the emergence ages were estimated by using feldspar OSL dating. This study was carried out as a part of the establishment of advanced technology for estimation of uplift rates using emergence ages of emergent landforms project.
Nishiyama, Nariaki*; Kawamura, Makoto; Umeda, Koji*; Goto, Akira; Niwa, Masakazu
no journal, ,
The topography of the volcanic mountain body is thought to reflect the actual distribution range of the dike. Based on this idea, we examined the modeling of the dike distribution and the evaluation of the central conduit stability focused on the shape of the contour lines. In this study, we drew the line with the maximum distance (long axis) in the contour distribution of each elevation and aggregated the orientation data, in addition to the data obtained from the analysis of Nishiyama et al. (2021). Moreover, we calculated the topographic parameter of each volcano, using the area data of the area enclosed by the contour lines (contour polygons). As a result, we found that the orientation of the long axis of the contour polygons of volcanic bodies shows the orientation trend in each volcano. The orientation of the line connecting the centroid of many volcanoes is consistent with that of the line connecting the centroid, which is roughly consistent with the direction of sigma 1 around the volcanoes. In general, dikes are characterized by extension in the direction of the maximum compression axis, and our topographic analysis results are consistent with this. As for the topographic parameters of each volcano using the area of contour polygons, the result suggests that it is possible to distinguish between volcanoes classified as central conduit stable and unstable by Takahashi (1994). Therefore, the topographic analysis is expected to be used to evaluate the stability of central conduit even for volcanoes whose activity history is not yet known. In the future, we will develop an evaluation method based on the above topographic features, and establish a method for evaluating the central conduit stability and modeling the distribution of dikes by topographic analysis.
Kawamura, Makoto; Nishiyama, Nariaki; Niwa, Masakazu; Umeda, Koji*
no journal, ,
As the efforts of the notation, "examination of the method of estimating the distribution range of the rock veins distributed under the Quaternary volcano body based on the topographical data of the numerical elevation model" and "Collection and organization of dikes from geological maps (database)" was carried out. These studies are expected to be used as basic information for evaluating the direction and range that are likely to be affected by the horizontal movement of magma due to future volcanic and igneous activities.
Tsukahara, Yuzuko; Ogata, Manabu; Kawamura, Makoto; Kanno, Mizuho*; Nishiyama, Nariaki; Sueoka, Shigeru; Nakanishi, Toshimichi*; Komatsu, Tetsuya
no journal, ,
One hundred thousand-year-scale uplift rate of the Japanese mountains is estimated mainly based on the Terrace to Terrace method (TT method; Yoshiyama and Yanagida, 1995). To apply the TT method, it is necessary to identify the pair of the sedimentary terraces of the last glacial period and the one before last glacial period. However, there are many mountains where such terrace pairs are not recognized. Therefore, as an alternative method to the TT method, we suggest the method based on landforms and deposits of incised meandering rivers (for example, Yasue et al., 2014; Ogata et al., 2021). In this presentation, we will report the results of a survey conducted in the middle of the Oi River as part of such research.
Hakoiwa, Hiroaki; Shimada, Koji; Kawamura, Makoto; Nishiyama, Nariaki; Goto, Akira*
no journal, ,
no abstracts in English
Kawamura, Makoto; Nishiyama, Nariaki; Jia, H.*; Koizumi, Yukiko*; Niwa, Masakazu; Umeda, Koji*
no journal, ,
Volcanic dykes were extracted from a geological map of 1/200,000, and location information was converted into GIS data. More than half of the major axis lengths of rock veins are less than 1 km, the distribution of quaternary volcanic dykes exposed on the surface is limited to within 10 km from the quaternary volcano. Regarding the relationship between the quaternary volcano and the dykes older than the quaternary period, it is considered that the relationship is low as a result of examining the relationship such as the distance and the extension direction of the dykes. We also examined the relationship between Neogene-Tertiary volcanic activity and the dykes distributed in the surrounding area. In the case of Ishizuchi Cauldron, it was shown that the maximum distance from the related rock veins was about 5 km. On the other hand, it was found that the dykes of the Kibi Plateau in the Chugoku region are distributed within a range of approximately 15 km from the central point of activity. Comprehensive information gathering as described above and statistical examination using them are useful as basic information for investigating and evaluating the range of influence of magma in the geological disposal.
