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Journal Articles

Application of probabilistic fracture mechanics methodology for Japanese reactor pressure vessels using PASCAL4

Lu, K.; Katsuyama, Jinya; Li, Y.; Yoshimura, Shinobu*

Proceedings of 2019 ASME Pressure Vessels and Piping Conference (PVP 2019) (Internet), 9 Pages, 2019/07

Journal Articles

Guideline on probabilistic fracture mechanics analysis for Japanese reactor pressure vessels

Katsuyama, Jinya; Osakabe, Kazuya*; Uno, Shumpei; Li, Y.; Yoshimura, Shinobu*

Proceedings of 2017 ASME Pressure Vessels and Piping Conference (PVP 2017) (CD-ROM), 9 Pages, 2017/07

A structural integrity assessment methodology based on probabilistic fracture mechanics (PFM) is a rational methodology in evaluating failure frequency of reactor pressure vessels (RPVs) by considering the probabilistic distributions of various influence factors related to the aged degradation. We have developed a PFM analysis code PASCAL to evaluate the failure frequency of RPVs considering the neutron irradiation embrittlement and pressurized thermal shock (PTS) events. We have also developed a guideline on the structural integrity assessment of RPVs based on PFM to improve the applicability of PFM in Japan and to be able to perform the PFM analyses and evaluate through-wall cracking frequency of RPVs. The technical basis for PFM analysis is provided and the latest knowledge is included in the guideline. In this paper, an overview of the guideline and some typical analysis results obtained based on the guideline and Japanese database related to PTS evaluation are presented.

Journal Articles

Benchmark analyses of probabilistic fracture mechanics for cast stainless steel pipe

Hojo, Kiminobu*; Hayashi, Shotaro*; Nishi, Wataru*; Kamaya, Masayuki*; Katsuyama, Jinya; Masaki, Koichi*; Nagai, Masaki*; Okamoto, Toshiki*; Takada, Yasukazu*; Yoshimura, Shinobu*

Mechanical Engineering Journal (Internet), 3(4), p.16-00083_1 - 16-00083_16, 2016/08

Performance demonstration certification of non-destructive inspection for cast stainless steel (CASS) has been planned but the target flaw depth to be detected has not been determined yet in Japan. The target flaw size is closely connected to the allowable flaw size which is determined by flaw evaluation of the rules on fitness-for-service. For rational mitigation of the acceptable flaw size, application of probabilistic fracture mechanics (PFM) is one of the useful countermeasures compared with deterministic approach. In this paper, benchmark problems for a CASS pipe were proposed with intention applying and verifying PFM codes. As the fracture modes, fatigue crack extension, plastic collapse and ductile crack initiation were assumed. Six organizations participated in the benchmark analysis and failure probabilities from them were compared. As a result the failure probability of each problem showed good agreement and the code for application of CASS issue has been verified.

Journal Articles

Study on application of PFM analysis method to Japanese code for RPV integrity assessment under PTS events

Osakabe, Kazuya*; Masaki, Koichi*; Katsuyama, Jinya; Katsumata, Genshichiro; Onizawa, Kunio; Yoshimura, Shinobu*

Proceedings of 2015 ASME Pressure Vessels and Piping Conference (PVP 2015) (Internet), 8 Pages, 2015/07

A probabilistic fracture mechanics (PFM) analysis method for pressure boundary components is useful to evaluate the structural integrity in a quantitative way. This is because the uncertainties related to influence parameters can be rationally incorporated in PFM analysis. From this viewpoint, the probabilistic approach evaluating through-wall cracking frequencies (TWCFs) of reactor pressure vessels (RPVs) has already been adopted as the regulation on fracture toughness requirements against PTS events in the U.S. As a study of applying PFM analysis to the integrity assessment of domestic RPVs, JAEA has been preparing input data and analysis models to calculate TWCFs using PFM analysis code PASCAL3. In this paper, activities have been introduced such as preparing input data and models for domestic RPVs, verification of PASCAL3, and formulating guideline on general procedures of PFM analysis for the purpose of utilizing PASCAL3. In addition, TWCFs for a model RPV evaluated by PASCAL3 are presented.

Journal Articles

Benchmark analysis on probabilistic fracture mechanics analysis codes concerning multiple cracks and crack initiation in aged piping of nuclear power plants

Li, Y.; Osakabe, Kazuya*; Katsumata, Genshichiro; Katsuyama, Jinya; Onizawa, Kunio; Yoshimura, Shinobu*

Proceedings of 2014 ASME Pressure Vessels and Piping Conference (PVP 2014) (DVD-ROM), 8 Pages, 2014/07

Multiple cracks in the same welded joints have been detected in piping systems of nuclear power plants. Therefore, structural integrity assessments considering multiple cracks and crack initiation in aged piping have been important. Probabilistic fracture mechanics (PFM) is a rational methodology in structural integrity assessment of aged piping in nuclear power plants. Two PFM codes, PASCAL-SP and PRAISE-JNES, have been improved or developed in Japan for the structural integrity assessment considering the age related degradation mechanisms of pipes. In this paper, a benchmark analysis was conducted considering multiple cracks and crack initiation, in order to confirm their reliability and applicability. Based on the numerical investigation in consideration of important influence factors such as crack number, crack location, crack distribution and crack detection probability of in-service inspection, it was concluded that the analysis results of these two codes are in good agreement.

Journal Articles

Benchmark analysis on probabilistic fracture mechanics analysis codes concerning fatigue crack growth in aged piping of nuclear power plants

Katsuyama, Jinya; Ito, Hiroto*; Li, Y.*; Osakabe, Kazuya*; Onizawa, Kunio; Yoshimura, Shinobu*

International Journal of Pressure Vessels and Piping, 117-118, p.56 - 63, 2014/05

 Times Cited Count:6 Percentile:38.54(Engineering, Multidisciplinary)

Several probabilistic fracture mechanical (PFM) analysis codes have been improved or developed in Japan, such as PASCAL-SP developed at JAEA, and PRAISE-JNES developed at JNES for structural integrity assessment of aged piping in nuclear power plants. Although they were developed for different purposes, they have similar functions. In this paper, in order to confirm the reliability and applicability of two PFM analysis codes, PASCAL-SP and PRAISE-JNES, benchmark analyses on piping failure probability have been carried out considering typical aging mechanisms, such as fatigue crack growth for piping materials in BWR plants Moreover, a criterion is proposed to judge whether the differences between the analysis results from two codes can be acceptable. Based on the proposed criterion, it is concluded that the analysis results of these two codes are in good agreements.

Journal Articles

International round robin analysis of probabilistic fracture mechanics for reactor pressure vessel during cool-down and LTOP event

Kanto, Yasuhiro*; Onizawa, Kunio; Osakabe, Kazuya*; Yoshimura, Shinobu*

Proceedings of 10th International Workshop on the Integrity of Nuclear Components (ASINCO-10), p.189 - 194, 2014/04

The international Round Robin (RR) activity was performed in PFM sub-committees in JWES in conjunction with Korea and Taiwan research groups. The purposes of this program were to establish reliable procedures to evaluate fracture probability of reactor pressure vessels during pressurized thermal shock and to maintain the continuous cooperation among Asian institutes in the probabilistic approach to nuclear safety. The results of this work were summarized at the previous ASINCO workshop in 2010. Here, as the phase 2 of the program, a new international round robin activity is planned. This paper describes the outline of the problem. The aims of the program and the matters to be noticed is presented.

Journal Articles

Seismic structural response estimates of a fault-structure system model with fine resolution using multiscale analysis with parallel simulation of seismic; Wave propagation

Quinay, P. E. B.*; Ichimura, Tsuyoshi*; Hori, Muneo*; Nishida, Akemi; Yoshimura, Shinobu*

Bulletin of the Seismological Society of America, 103(3), p.2094 - 2110, 2013/06

 Times Cited Count:7 Percentile:64.74(Geochemistry & Geophysics)

We studied the seismic structural response of a fault-structure system using a large-scale, highfidelity model with multiscale analysis and parallel simulation. To reduce the computation cost of simulating seismic wave propagation (Ichimura and Hori, 2006), we extended the seismic wave propagation simulation tool to parallel computing which uses a distributed-memory computer. We developed a method for prepartitioning the three-dimensional model and performing the neighbor-independent submodel hybrid-grid meshing. We then verified and validated the extended simulation tool. Finally, we demonstrated its advantages for computing the dynamic responses of a fault-structure system model that includes a building structure of nuclear power plant, using a high fidelity model which is based on actual settings.

Journal Articles

Benchmark analysis and numerical investigation on probabilistic fracture mechanics analysis codes for NPPs piping

Li, Y.*; Ito, Hiroto*; Osakabe, Kazuya*; Onizawa, Kunio; Yoshimura, Shinobu*

International Journal of Pressure Vessels and Piping, 99-100, p.61 - 68, 2012/11

 Times Cited Count:6 Percentile:43.49(Engineering, Multidisciplinary)

A benchmark analysis was conducted using two probabilistic fracture mechanics analysis codes for aged piping in nuclear power plants, in order to confirm their reliability and applicability. These analysis codes have been improved or developed in Japan for the structural integrity evaluation and risk assessment considering the age related degradation mechanisms. In the benchmark analysis, the primary loop recirculation system piping in the boiling water reactor was selected as the typical piping system and stress corrosion cracking and fatigue were taken into account as the typical aging mechanisms. Moreover, a criterion was proposed for judging whether the differences between analysis results from the two codes are acceptable. Based on the benchmark analysis results and numerical investigation, it was concluded that the analysis results of these two codes agree very well.

Journal Articles

An Integrated geologic- and engineering-length scale forward modeling for response estimation of nuclear power plant due to the rupture of a nearby fault

Quinay, P. E.*; Ichimura, Tsuyoshi*; Hori, Muneo*; Nishida, Akemi; Yoshimura, Shinobu*

Proceedings of 15th World Conference on Earthquake Engineering (WCEE-15) (USB Flash Drive), 8 Pages, 2012/09

In this paper we discuss the development of seismic response estimation method for nuclear power plant building structures based on fault-structure system. In analysing this system, we model the source process, seismic wave propagation in the crust and soil structure, and the dynamic response of the building structure. Due to the varied length-scales involved in simulating from the fault rupture to the building dynamic response, the computation cost of analysis is high. Thus, we perform the analysis by combining a multiscale approach called the Macro-Micro Analysis (MMA), and distributed-memory parallel computing. As an application example, we compute the response of a model of a nuclear power plant building with the 2007 Chuetsu-oki earthquake as the source. We target accuracy of the forward modelling up to 1.0 Hz. Advantages for the analysis of NPP building in the structure-level and in the finite element level are discussed.

Journal Articles

Benchmark analysis on PFM analysis codes for aged piping of nuclear power plants

Ito, Hiroto*; Li, Y.*; Osakabe, Kazuya*; Onizawa, Kunio; Yoshimura, Shinobu*

Journal of Mechanical Science and Technology, 26(7), p.2055 - 2058, 2012/07

 Times Cited Count:2 Percentile:80.34(Engineering, Mechanical)

Probabilistic fracture mechanics is a rational methodology in the structural integrity evaluation and risk assessment for aged piping in nuclear power plants. Several probabilistic fracture mechanical analysis codes have been improved or developed in Japan. In this paper, to verify the reliability and applicability of two of these codes, a benchmark analysis was conducted using their basic functions in consideration of representative piping systems in nuclear power plants and typical aging mechanisms. Based on the analysis results, we concluded that the analysis results of these two codes are in good agreement.

Journal Articles

Summary of International PFM Round Robin analyses among Asian Countries on reactor pressure vessel integrity during pressurized thermal shock

Kanto, Yasuhiro*; Jhung, M.*; Ting, K.*; He, Y.*; Onizawa, Kunio; Yoshimura, Shinobu*

International Journal of Pressure Vessels and Piping, 90-91, p.46 - 55, 2012/02

 Times Cited Count:11 Percentile:29.05(Engineering, Multidisciplinary)

The International Round Robin (RR) activity was performed by the Probabilistic Fracture Mechanics (PFM) sub-committees of the Atomic Energy Research Committee of the Japan Welding Engineering Society (JWES) in conjunction with Korean, Taiwanese and Chinese research groups. The purposes of this program are to establish reliable procedures for evaluating the fracture probability of reactor pressure vessels (RPVs) during pressurized thermal shock (PTS) and to maintain the continuous cooperation among Asian institutes in the probabilistic approach to nuclear safety. This paper describes the outline of the problems and summarizes the results from all participant countries. The RR activity consists of two parts; deterministic analyses on stress and temperature in the reactor pressure vessel wall during PTS, and probabilistic analyses on vessel fracture probability due to PTS transients. The differences caused by the selection of analyzing programs and some input parameters are discussed.

Journal Articles

Progress of large scale seismic simulation for nuclear power plant in its entirety

Yamada, Tomonori; Shioya, Ryuji*; Yoshimura, Shinobu*

Shimyureshon, 30(2), p.65 - 69, 2011/06

In this paper, recent progress of full-scale simulation of nuclear power plant in its entirety with the growth of supercomputing resource is described. Future directions and possibility and also difficulties are discussed.

Journal Articles

International PFM Round Robin analyses by Japanese participants on reactor pressure vessel integrity during pressurized thermal shock

Onizawa, Kunio; Kanto, Yasuhiro*; Yoshimura, Shinobu*

Proceedings of 8th International Workshop on the Integrity of Nuclear Components 2010, p.137 - 146, 2010/04

The international Round Robin (RR) activity was established in PFM sub-committee in the Japan Welding Engineering Society. This paper summarizes the results from six Japanese participants in the international RR on probabilistic fracture mechanics (PFM) analyses on reactor pressure vessel integrity during pressurized thermal shock (PTS). The RR activity consists of two parts; deterministic analysis on temperature and stress during PTS, and probabilistic analysis on vessel fracture probability. The results from deterministic analysis by five participants were agreed well with among others. One exceptional case was calculation results based on a newly-developed finite difference method. For probabilistic analysis all participants used the same PFM analysis code PASCAL2. Results from five participants were compared with regard to the effects of inspection performance, Cu content and initial reference temperature on fracture probability. The results gave a reasonable agreement although slight differences among participants were found. The differences caused by the selection of some inputs and simulation method are discussed.

Journal Articles

Recent Japanese research activities on probabilistic fracture mechanics for pressure vessel and piping of nuclear power plant

Kanto, Yasuhiro*; Onizawa, Kunio; Machida, Hideo*; Isobe, Yoshihiro*; Yoshimura, Shinobu*

International Journal of Pressure Vessels and Piping, 87(1), p.11 - 16, 2010/01

 Times Cited Count:10 Percentile:32.77(Engineering, Multidisciplinary)

JAEA had sponsored research committees on probabilistic fracture mechanics (PFM) organized by the Japan Welding Engineering Society (JWES) for more than a decade. This work still continues with the same members in JWES. The purpose of the continuous activity is to provide probabilistic approaches in several fields of integrity problems of nuclear power plant. This paper shows some of the newest results of the JWES research committee. First topic is evaluation of the new JSME code case with rules of fitness-for-service from the view of PFM, including reactor pressure vessel subject to pressurized thermal shock loading, piping with a crack of the allowable size and effect of sizing accuracy for piping integrity. Another is development of new PFM techniques including reliability assessment of piping with domestic SCC data and maintenance optimization of LWRs based on risk and economic models. The last topic is the international round robin program just starting from 2008.

Journal Articles

Prediction and numerical validation of optimal number of subdomains on balancing domain decomposition method

Yamada, Tomonori; Ogino, Masao*; Yoshimura, Shinobu*

Nippon Keisan Kogakkai Rombunshu (Internet), 2009(14), 7 Pages, 2009/08

Computation efficiency of the balancing domain decomposition method is investigated in this paper. An iterative substructuring method with coarse grid correction is one of the most effective methods for parallel computing of large scale structural finite element analyses. In this study, a prediction curve of parallel computation cost of the balancing domain decomposition method is proposed, and the optimal number of subdomains is estimated. Numerical validation of the optimal number of subdomains is conducted and the measured computation time with the optimal number of subdomains shows better computation performance than those with other numbers of subdomains.

Journal Articles

Grid use not to consider grid; Proposal of seamless API and adaptation to applications

Nakajima, Kohei; Suzuki, Yoshio; Teshima, Naoya; Sugimoto, Shinichiro*; Yoshimura, Shinobu*; Nakajima, Norihiro

Zen NEC C&C Shisutemu Yuza Kai Heisei-20-Nendo Rombunshu (CD-ROM), 13 Pages, 2009/02

Grid computing environment is equipped with a lot of tools to manage jobs and computers. Thereby, user can use the computers without directly access. However, user has to acquire usage of these tools even when user does an easy job because all usages of these tools are peculiar to the grid base. A lot of users think that the grid is difficult even though these tools exist. Then, we developed script generator API to make the job script. These settings were made easy by this API in the user application. In this paper, the outline of this API and the adjustment to the application are described.

Journal Articles

Recent Japanese research activities on probabilistic fracture mechanics for pressure vessel and piping of nuclear power plant

Kanto, Yasuhiro*; Onizawa, Kunio; Machida, Hideo*; Isobe, Yoshihiro*; Yoshimura, Shinobu*

Proceedings of 7th International Conference on the Integrity of Nuclear Components, p.219 - 228, 2008/07

This paper describes a review of recent Japanese activities on probabilistic fracture mechanics (PFM) analyses. JAEA had sponsored research committees on PFM organized by the Japan Society of Mechanical Engineers and the Japan Welding Engineering Society (JWES) for more than a decade. This work still continues with the same members in JWES. The purpose of the continuous activity is to provide probabilistic approaches in several fields of integrity of reactor components. This paper summarizes some of the latest results of this activity. First topic is evaluation of the JSME rules on Fittness-For-Service from the view of PFM, including reactor pressure vessel with a crack of the allowable size, and effect of sizing accuracy in inspection. The next one is development of new PFM techniques including piping reliability assessment on domestic SCC data and maintenance optimization based on risk and economic models. The last is the international round robin program just starting from 2008.

Journal Articles

Implementation of ADVENTURE_Opt in the ITBL environment using ITBL client API

Miyamura, Tomoshi*; Arai, Kentaro*; Mimura, Yasunari*; Yoshimura, Shinobu*; Suzuki, Yoshio

Keisan Kogaku Koenkai Rombunshu, 12(2), p.655 - 658, 2007/05

ADVENTURE_Opt is one of the software modules in the ADVENTURE System, which is an open source software system for computational mechanics. The system is designed for conducting large-scale analysis and design. ADVENTURE_Opt can conduct optimization of artifacts using an optimization algorithm such as the Real coded GA, and the finite element analyses are conducted for evaluating an objective function. In this paper, the ADVENTURE_Opt is modified for using the ITBL environment, which is a grid-environment developed in the national project in Japan. In the computation using the ADVENTURE_Opt, conducting the finite element analyses is the most time consuming. In the present implementation, this computation is conducted in the ITBL environment and the other parts are conducted on a personal computer. The ITBL client API library is used for implementing the system.

Journal Articles

Comprehensive study on layout dependence of soft errors in CMOS latch circuits and its scaling trend for 65 nm technology node and beyond

Fukui, Hironobu*; Hamaguchi, Masafumi*; Yoshimura, Hisao*; Oyamatsu, Hisato*; Matsuoka, Fumitomo*; Noguchi, Tatsuo*; Hirao, Toshio; Abe, Hiroshi; Onoda, Shinobu; Yamakawa, Takeshi; et al.

Proceedings of 2005 Symposia on VLSI Technology and Circuits, p.222 - 223, 2005/00

no abstracts in English

32 (Records 1-20 displayed on this page)