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Journal Articles

Method for detecting optimal seismic intensity index utilized for ground motion generation in seismic PRA

Igarashi, Sayaka*; Sakamoto, Shigehiro*; Ugata, Takeshi*; Nishida, Akemi; Muramatsu, Ken*; Takada, Tsuyoshi*

Transactions of 24th International Conference on Structural Mechanics in Reactor Technology (SMiRT-24) (USB Flash Drive), 10 Pages, 2017/08

For the purpose of improving the precision of probabilistic seismic PRA for NPPs, the authors developed the methodology for generating hazard-consistent ground motions based on stochastic fault models which include seismic-source uncertainties by Monte Carlo Simulation. The PRA with HCGMs would require a lot of computer power. The optimization of ground-motions generations is one of the most important subjects for practical application of the PRA method. For optimizing the ground-motions generations, seismic sources for the generations should be selected effectively, and this can be conducted by utilizing optimal seismic index in the hazard analysis. In this study, the method for detecting the optimal seismic intensity index which corresponds with damage probabilities of the target equipment system was developed, and the validity of the proposed method was confirmed for some equipment systems, which has different weak equipment with each other.

Journal Articles

Hazard-consistent ground motions generated with a stochastic fault-rupture model

Nishida, Akemi; Igarashi, Sayaka*; Sakamoto, Shigehiro*; Uchiyama, Yasuo*; Yamamoto, Yu*; Muramatsu, Ken*; Takada, Tsuyoshi*

Nuclear Engineering and Design, 295, p.875 - 886, 2015/12

 Times Cited Count:2 Percentile:17.75(Nuclear Science & Technology)

Most probabilistic risk assessments (PRA) of structures involve the use of probabilistic schemes such as the scheme using probabilistic seismic hazard and fragility curves. Even when earthquake ground motions are required in Monte Carlo Simulations (MCS), they are generated to fit the specified response spectra, such as uniform hazard spectra at a specified exceedance probability. These ground motions, however, are not directly linked with corresponding seismic source characteristics. In this paper, the authors propose a methodology based on MCS to reproduce a set of input ground motions to develop an advanced PRA scheme that can explain the exceedance probability and sequence of functional loss in a nuclear power plant. These generated motions are consistent with the seismic hazard for the target site and their seismic source characteristics can be recognized in detail.

Journal Articles

Seismic response analysis of reactor building and equipment using a 3D-FE model for reliability enhancement of seismic risk assessment of NPP

Nishida, Akemi; Igarashi, Sayaka*; Sakamoto, Shigehiro*; Muramatsu, Ken; Takada, Tsuyoshi*

Dai-8-Kai Kozobutsu No Anzensei, Shinraisei Ni Kansuru Kokunai Shimpojiumu (JCOSSAR 2015) Koen Rombunshu (CD-ROM), p.108 - 113, 2015/10

Research and development on next-generation seismic probabilistic risk assessment by using 3D vibration simulators is ongoing to evaluate the seismic safety performance of nuclear plants with high reliability. Most structural PRA uses probabilistic schemes such as the scheme that uses probabilistic seismic hazard and fragility curves. Even when earthquake ground motions are required in Monte Carlo Simulations (MCS), they are generated to fit the specified response spectra, such as uniform hazard spectra at a specified exceedance probability. However, these ground motions are not directly linked with their corresponding seismic source characteristics. In this context, the authors propose a methodology based on MCS to reproduce a set of input ground motions to develop an advanced PRA scheme. This paper describes the methodology to reproduce a set of input ground motions briefly and the analytical results of a nuclear plant building and equipment using the set of input ground motions.

Journal Articles

Study on building function loss evaluated by hazard-consistent ground motions

Igarashi, Sayaka*; Sakamoto, Shigehiro*; Nishida, Akemi; Muramatsu, Ken; Takada, Tsuyoshi*

Dai-8-Kai Kozobutsu No Anzensei, Shinraisei Ni Kansuru Kokunai Shimpojiumu (JCOSSAR 2015) Koen Rombunshu (CD-ROM), p.535 - 541, 2015/10

In this study, building function loss induced by hazard-consistent ground motions (HCGMs), which are consistent with seismic hazard of the reference site and are associated with seismic source characteristics, was evaluated in order to confirm the influence by the variance and/or inter-period correlation of response spectra of ground motions on the resulted damage probabilities of equipment system. Firstly, the statistics values of the response spectra of HCGMs were evaluated, and 3 cases of simulated ground-motions sets are generated so that they fit to the median response spectra of HCGMs. The authors conducted structural response analysis with these ground motions set, and calculated annual damage frequency of equipment system. As a result, it was found that the variance of response spectra was more important factor on damage probability evaluation of systems than inter-period correlation.

Journal Articles

Seismic damage probability by ground motions consistent with seismic hazard

Igarashi, Sayaka*; Sakamoto, Shigehiro*; Uchiyama, Yasuo*; Yamamoto, Yu*; Nishida, Akemi; Muramatsu, Ken; Takada, Tsuyoshi*

Transactions of 23rd International Conference on Structural Mechanics in Reactor Technology (SMiRT-23) (USB Flash Drive), 10 Pages, 2015/08

In the preceding study, the methodology to generate ground-motion time histories for advanced PRA of NPPs was proposed by Nishida et al.. They are consistent with seismic hazard at reference site, and incorporate uncertainties of seismic-source characteristics. The ground motions utilized in conventional PRA are generated to fit to specified spectra such as UHS, and they are often generated without considering the variation of spectra. Even if it is considered, their inter-period correlations are generally assumed to be 1.0. In this paper, the authors prepared some cases of ground-motions sets. Ground motions are generated to fit to the response spectra calculated from hazard-consistent ground motions. While the target response spectra have the same median for all case, they have different variation and inter-period correlation. The response analyses of general RC structure and PWR building are conducted and the damage frequencies of simplified equipment system are compared.

Journal Articles

Structural response by ground motions from sources with stochastic characteristics

Igarashi, Sayaka*; Sakamoto, Shigehiro*; Nishida, Akemi; Muramatsu, Ken; Takada, Tsuyoshi*

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 10 Pages, 2015/05

In the preceding study, the ground-motion time histories consistent with seismic hazard were generated by Nishida et al.. In this study, structural response analyses of general RC structure are conducted with the 2,736 waves of ground motions which were generated from one seismic source, minami-kanto earthquakes. These ground motions incorporate the differences of their seismic-source characteristics. The multi-regression analyses are also conducted with the results of response analysis. As a result, the seismic moment, stress drop and Q-value coefficient showed clear positive correlation with seismic intensities and maximum structural responses. This can be expressed by the relationship between the Fourier spectra of seismic source and seismic-source characteristics. On the other hand, asperity location showed negative correlation with seismic intensities and maximum structural responses. The trend can be expressed by the relationship of location between reference site and faults.

Journal Articles

Characteristics of simulated ground motions consistent with seismic hazard

Nishida, Akemi; Igarashi, Sayaka*; Sakamoto, Shigehiro*; Uchiyama, Yasuo*; Yamamoto, Yu*; Muramatsu, Ken*; Takada, Tsuyoshi*

Transactions of 22nd International Conference on Structural Mechanics in Reactor Technology (SMiRT-22) (CD-ROM), 10 Pages, 2013/08

Most probabilistic risk assessments (PRA) of structures involve the use of probabilistic schemes such as the scheme using probabilistic seismic hazard and fragility curves. Even when earthquake ground motions are required in Monte Carlo Simulations (MCS), they are generated to fit the specified response spectra, such as uniform hazard spectra at a specified exceedance probability. These ground motions, however, are not directly linked with corresponding seismic source characteristics. In this context, the authors propose a methodology based on MCS to reproduce a set of input ground motions to develop an advanced PRA scheme that can explain the exceedance probability and sequence of functional loss in a nuclear power plant. These generated motions are consistent with the seismic hazard for the target site and their seismic source characteristics can be recognized in detail.

Journal Articles

Molecular analysis of carbon ion induced mutations in the yeast ${it ogg1}$ and ${it msh2}$ mutants

Matsuo, Yoichiro*; Nishijima, Shigehiro*; Hase, Yoshihiro; Nozawa, Shigeki; Sakamoto, Ayako; Narumi, Issei; Shimizu, Kikuo*

JAEA-Review 2009-041, JAEA Takasaki Annual Report 2008, P. 75, 2009/12

no abstracts in English

Journal Articles

Study on molecular mechanism of high-LET carbon ion beam induced mutations in ${it S. cerevisiae}$

Matsuo, Yoichiro*; Nishijima, Shigehiro*; Hase, Yoshihiro; Sakamoto, Ayako; Narumi, Issei; Shimizu, Kikuo*

JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 60, 2008/11

no abstracts in English

Journal Articles

Study of molecular mechanism of carbon ion beam induced mutations in the ${it Saccharomyces cerevisiae}$

Matsuo, Yoichiro*; Nishijima, Shigehiro*; Hase, Yoshihiro; Sakamoto, Ayako; Yokota, Yuichiro; Narumi, Issei; Shimizu, Kikuo*

JAEA-Review 2007-060, JAEA Takasaki Annual Report 2006, P. 86, 2008/03

no abstracts in English

Journal Articles

Study of molecular mechanism of ion beam induced mutations in the ${it Saccharomyces cerevisiae}$

Matsuo, Yoichiro*; Nishijima, Shigehiro*; Hase, Yoshihiro; Sakamoto, Ayako; Tanaka, Atsushi; Shimizu, Kikuo*

JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 76, 2007/02

no abstracts in English

Journal Articles

Specificity of mutations induced by carbon ions in budding yeast ${it Saccharomyces cerevisiae}$

Matsuo, Yuichiro*; Nishijima, Shigehiro*; Hase, Yoshihiro; Sakamoto, Ayako; Tanaka, Atsushi; Shimizu, Kikuo*

Mutation Research; Fundamental and Molecular Mechanisms of Mutagenesis, 602(1-2), p.7 - 13, 2006/12

 Times Cited Count:28 Percentile:58.33(Biotechnology & Applied Microbiology)

no abstracts in English

Oral presentation

Molecular analysis of heavy ion induced mutations in budding yeast ${it Saccharomyces cerevisiae}$

Matsuo, Yoichiro*; Nishijima, Shigehiro*; Hase, Yoshihiro; Sakamoto, Ayako; Tanaka, Atsushi; Shimizu, Kikuo*

no journal, , 

no abstracts in English

Oral presentation

Mechanisms of mutation induction in budding yeast by heavy ion irradiation

Matsuo, Yoichiro*; Nishijima, Shigehiro*; Shimizu, Kikuo*; Hase, Yoshihiro; Sakamoto, Ayako; Tanaka, Atsushi

no journal, , 

no abstracts in English

Oral presentation

Analysis of molecular mechanism of mutations induced by heavy ion beams

Matsuo, Yoichiro*; Nishijima, Shigehiro*; Hase, Yoshihiro; Sakamoto, Ayako; Tanaka, Atsushi; Shimizu, Kikuo*

no journal, , 

no abstracts in English

Oral presentation

Relationship between mechanisms of mutation induction by heavy ion beam irradiation and nucleosome structure

Matsuo, Yoichiro*; Nishijima, Shigehiro*; Shimizu, Kikuo*; Hase, Yoshihiro; Sakamoto, Ayako; Narumi, Issei

no journal, , 

no abstracts in English

Oral presentation

Molecular analysis of carbon ion induced mutations in the budding yeast Saccharomyces cerevisiae

Matsuo, Yoichiro*; Nishijima, Shigehiro*; Hase, Yoshihiro; Yokota, Yuichiro; Sakamoto, Ayako; Narumi, Issei; Shimizu, Kikuo*

no journal, , 

no abstracts in English

Oral presentation

Analysis of mutagenesis mechanisms of budding yeast by carbon ion beam irradiation

Matsuo, Yoichiro*; Nishijima, Shigehiro*; Hase, Yoshihiro; Sakamoto, Ayako; Narumi, Issei; Shimizu, Kikuo*

no journal, , 

no abstracts in English

Oral presentation

Molecular analysis of carbon ion induced mutants in the budding yeast ${it Saccharomyces cerevisiae}$

Matsuo, Yoichiro*; Nishijima, Shigehiro*; Hase, Yoshihiro; Yokota, Yuichiro; Sakamoto, Ayako; Narumi, Issei; Shimizu, Kikuo*

no journal, , 

no abstracts in English

Oral presentation

Oxidative damage and mutation induction mechanisms by heavy ion beam irradiation

Matsuo, Yoichiro*; Nishijima, Shigehiro*; Hase, Yoshihiro; Sakamoto, Ayako; Narumi, Issei; Shimizu, Kikuo*

no journal, , 

no abstracts in English

35 (Records 1-20 displayed on this page)