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Journal Articles

JAEA activities related to the use of computer programs and databases in the nuclear field

Suzuki, Yoshio; Otani, Takayuki; Sakamoto, Kensaku; Takakura, Masahiro*; Kuwabara, Yasuhiro*

Proceedings of Joint International Conference on Supercomputing in Nuclear Applications + Monte Carlo 2020 (SNA + MC 2020), p.287 - 294, 2020/10

HPC Technology Promotion Office, Center for Computational Science and e-systems (CCSE) of Japan Atomic Energy Agency (JAEA) is responsible for the administration of computer programs (CPs) and databases (DBs) developed in JAEA to disseminate R&D results in JAEA to the outside and improve R&D efficiency. The information of these CPs and DBs can be found using Program and Database retrieval System (PRODAS) (https://prodas.jaea.go.jp), which is developed by our team. Those in Japan can also obtain CPs and DBs in the nuclear field possessed in OECD NEA Data Bank (NEADB), Radiation Safety Information Computational Center (RSICC) in the United States, and International Atomic Energy Agency (IAEA). In this paper, the recent situation of possession and dispatch of CPs and DBs developed within JAEA and the frameworks to obtain and provide CPs and DBs in nuclear field worldwide are presented.

JAEA Reports

Error estimation in observed acceleration data toward V&V of a seismic simulation

Suzuki, Yoshio; Iigaki, Kazuhiko

JAEA-Data/Code 2018-009, 41 Pages, 2018/09

JAEA-Data-Code-2018-009.pdf:3.14MB

Toward Verification & Validation (V&V) of a seismic simulation of entire nuclear plant, an approach to estimate errors included in observed acceleration data is proposed. On the comparison between simulation results and experimental/observational results in the process of V&V, errors which might be included in experimental/observational data should be estimated. It is considered that there exist following two causes for errors in observed acceleration data; measurement accuracy of an accelerometer measurement system and disturbance included in measured data. Techniques based on the specification of an accelerometer measurement system and the time series analysis are respectively adopted to estimate those errors. To clarify the actual procedure, those techniques are applied to acceleration data observed at High Temperature engineering Test Reactor (HTTR) at the Oarai Research and Development Institute of Japan Atomic Energy Agency.

Journal Articles

Investigation of error estimation method of observational data and comparison method between numerical and observational results toward V&V of seismic simulation

Suzuki, Yoshio; Kawakami, Yoshiaki*; Nakajima, Norihiro

Mechanical Engineering Reviews, 4(1), p.15-00525_1 - 15-00525_18, 2017/01

The method to estimate errors included in observational data and the method to compare numerical results with observational results are investigated toward the verification and validation (V&V) of a seismic simulation. For the method to estimate errors, it is found that errors are caused by the resolution, the linearity, the temperature coefficient for sensitivity, the temperature coefficient for zero shift, the transverse sensitivity, the seismometer property, the aliasing, and so on. Thus, it is needed to estimate errors individually for those factors and integrate them. For the method to compare numerical results with observational results, it is found that six methods have been mainly proposed in existing researches. Evaluating those methods using nine items, advantages and disadvantages for those methods are arranged. The method is not well established so that it is necessary to employ those methods by compensating disadvantages and/or to search for a solution to a novel method.

Journal Articles

An Illustration by the next generation numerical simulator for quake-proofing on the K

Nakajima, Norihiro; Suzuki, Yoshio; Miyamura, Hiroko; Nishida, Akemi; Kawakami, Yoshiaki; Guo, Z.; Tomiyama, Eiji*

Keisan Kogaku, 20(4), p.3338 - 3340, 2015/12

The issue 5 in the field 4 of "Monodukuri" in the HPCI strategy project is introduced. The title of the issue 5 is "research and development for the next-generation earthquake-resistant simulation of the large plants such as nuclear energy facilities". The illustration intends for a high temperature engineering examination research reactor. Implementation of FIESTA (Finite Element Analysis for Structure of Assembly) on K is described by reporting its efficiency and performance. To show a result of the numerical analysis, a visualization technique for the big data was described.

Journal Articles

Time domain response analysis for assembly by integrating components

Nakajima, Norihiro; Nishida, Akemi; Kawakami, Yoshiaki; Suzuki, Yoshio; Matsukawa, Keisuke*; Oshima, Masami*; Izuchi, Hisao*

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

The digital shaking table is introduced to carry out numerical experiments for the so called STRUCTURE of a petroleum plant. In numerical experiments, STRUCTURE was precisely modelled as it is designed and meshed into fine finite elements. The components of STRUCTURE were meshed one by one, and the code of a finite element analysis for structure of assembly gathered every meshed components to run time domain response analysis. Four waves are applied to the analysis to determine its behaviour. Four waves are namely as El Centro, Taft, Hachinohe, and Geiyo. The results of experiments are discussed by comparing accumulating data in the past. It is concluded to reconfirm the methodology of gathering meshed components and a finite element analysis for structure of assembly with the STRUCTURE.

Journal Articles

Numerical modeling assistance system in finite element analysis for the structure of an assembly

Nakajima, Norihiro; Nishida, Akemi; Kawakami, Yoshiaki; Suzuki, Yoshio; Sawa, Kazuhiro; Iigaki, Kazuhiko

Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 5 Pages, 2015/05

A numerical analysis controlling and managing system is implemented on K, which controls the modelling process and data treating, although the manager only controls a structural analysis by finite element method. The modeling process is described by the list of function ID and its procedures in a data base. The manager executes the process by order in the list for simulation procedures. The manager controls the intention of an analysis by changing the analytical process one to another. Experiments were carried out with static and dynamic analyses.

Journal Articles

2-dimentional visualization technique for exploring region of interest in 4-dimensional data

Miyamura, Hiroko; Kawamura, Takuma; Suzuki, Yoshio; Idomura, Yasuhiro; Takemiya, Hiroshi

Joho Shori Gakkai Rombunshi, 55(9), p.2216 - 2224, 2014/09

In numerical simulations, variations of calculation results with respect to a variable axis are often observed. When the target model is given in 3D, the simulation results become 4D. Such a multi-dimensional dataset given in more than 4D space is analyzed by detailed explorations of regions of interest (ROIs) in multi-dimensional space. However, for high-dimensional and large-scale datasets, this approach requires enormous processing time and effort, and may have difficulty in capturing all the ROIs. Therefore, we propose a technique that is based on a concept of spatiotemporal image. In our technique, a space axis is created by octree, a variable axis is defined in the direction perpendicular to the space axis. Our technique is applied to the results of 3D seismic simulations of a nuclear plant, and regions with characteristic frequency responses of each region are analyzed. Through the analyses, it is demonstrated that our technique can effectively capture ROIs from 4D datasets.

Journal Articles

Development of numerical modeling assistance system for finite element analysis

Nakajima, Norihiro; Nishida, Akemi; Kawakami, Yoshiaki; Suzuki, Yoshio

Nihon Kikai Gakkai Dai-24-Kai Sekkei Kogaku, Shisutemu Bumon Koenkai Koen Rombunshu (USB Flash Drive), 9 Pages, 2014/09

In this paper, a numerical analysis's controlling and managing system is suggested, which controls the modelling process and data treating for structural robustness, although a numerical analysis's manager only controls a structural analysis by finite element method. The modeling process is described by the list of function ID and its procedures in a data base. The analytical modeling manager executes the process by order of the lists for simulation procedures. The manager controls the intention of an analysis by changing the analytical process one to another. Modeling process was experimentally found that may subject to the intention of designing index. In the numerical experiments, K, supercomputer is utilized by using parallel computing resource with the controlling and managing system.

Journal Articles

Assembly structure analysis system

Nakajima, Norihiro; Nishida, Akemi; Matsubara, Hitoshi*; Hazama, Osamu*; Suzuki, Yoshio; Sawa, Kazuhiro; Iigaki, Kazuhiko

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

It is not convenient to experimentally analyze its behavior under strong loads of earthquakes, since the facility is extremely huge and complex. The proposed system performs numerical simulations to evaluate the behaviors of an assembly like a nuclear facility. This system projects the components of an assembly onto both/either a distributed and/or a parallel computing environment in order to conduct a simulation of the behavior of an assembly such as a nuclear facility. In a result discussion, a numerical experiment was carried out with a cantilever model and its result was compared with theoretical data. A good corresponding among them was obtained as a structural analysis of an assembly by using a parallel computer. As a conclusion, a suggested methodology has shown to calculate a behavior of an assembly with High Temperature engineering Test Reactor.

Journal Articles

An Introduction to visualization

Miyachi, Hideo*; Araki, Fumiaki*; Suzuki, Yoshio

Kashika Nyumon, 224 Pages, 2013/01

The visualization means "to make an invisible thing an visible thing", and "to make an visible thing an easily understandable thing. Widely, a clock which makes time a visible thing, and a speed meter which makes speed of a car an visible thing are a device of the visualization, however, in this book we introduce the image processing of the simulation result for the purpose of the confirmation, evaluation, and transmission of the simulation result. In this book we carefully explain the PC environment and the data conversion process for visualizatoin, the basic knowledge about computer graphics, the setting of visualization methods and their parameters, a role of the visualization in the numerical simulation, and a way of thinking of the visualization in the presentation.

Journal Articles

Research and development of full-scale three-dimensional vibration simulator for nuclear plant

Nishida, Akemi; Suzuki, Yoshio; Yamada, Tomonori; Kino, Chiaki; Uzawa, Ken*; Miyamura, Hiroko; Kawamura, Takuma; Takemiya, Hiroshi; Nakajima, Norihiro

RIST News, (54), p.33 - 37, 2013/01

Nuclear plants are complicated and huge structures and consist of a large number of parts. To simulate the behavior of such a complicated huge structure, it becomes important the viewpoint as a general system including pre-post-processing. Therefore, the CCSE proposed an approach for assembly structure analysis and implemented a framework of a full-scale 3D vibration simulator for an entire nuclear plant. Until now, we performed numerical experiments using the data of a building and equipment of HTTR, Oarai R&D Center, JAEA, and demonstrated that earthquake response simulation of large-scale structure as an entire nuclear plant was possible so far. In this report, the framework of the full-scale 3D vibration simulator, the assembly structure analysis approach and visualization technology for an evaluation of the results are shown. And finally, an example of application of the simulator for probabilistic risk assessment, PRA, started from 2011, is shown.

Journal Articles

R&D of a zooming analysis to verify a seismic simulation of an entire nuclear plant

Suzuki, Yoshio; Hoshi, Yoshiyuki*; Sakamoto, Kensaku; Nakajima, Norihiro

Proceedings of 4th International Conference on Computational Methods (ICCM 2012) (USB Flash Drive), 9 Pages, 2012/11

We research and develop a three-dimensional vibration simulator for an entire nuclear plant aiming at technical advances for more rational safety assessment of nuclear plant under an earthquake. The simulator includes "an entire structural simulation of ground-building-equipments (beam model)" and "an assembly structural simulation of parts to equipments (solid model)". As one approach to examine the quality of solid model which consists of thousands of parts, we have established a trial tool to perform the assembly structural simulation for a small number of parts by zooming in on a part of equipments in the entire structural simulation, and to compare results. To verify the tool, we applied the tool to static and dynamic simulations for a cantilever with various cross sections, and a static simulation of a small number of parts of nuclear plant, and confirmed results for solid model well coincide with those for beam model.

Journal Articles

R&D of validity evaluation system for seismic simulation of entire nuclear plant

Suzuki, Yoshio; Miyamura, Hiroko; Nakajima, Norihiro

Proceedings of 20th International Conference on Nuclear Engineering and the ASME 2012 Power Conference (ICONE-20 & POWER 2012) (DVD-ROM), 9 Pages, 2012/07

To estimate real behavior accurately by numerical simulations, it is indispensable to evaluate validity of simulation results because numerical simulations include various uncertainties such as "uncertainty due to randomness" and "uncertainty due to lack of knowledge". As one of approaches to evaluate validity of simulation results, we introduce "the degree of certainty" of simulations to real behavior. Here, to get a more accurate degree of certainty, we try to confirm the degree of influence about unevenness of uncertainty and to reduce uncertainty due to lack of knowledge. For this, we research and develop a validity evaluation system composed of three tools. We have applied them to our seismic simulation system which enables to execute the assembly structure analysis of an entire nuclear plant and confirmed that their functions are applicable to the simulation.

Journal Articles

R&D of verification & validation for seismic simulation of nuclear plant

Suzuki, Yoshio; Nishida, Akemi; Uzawa, Ken; Nakajima, Norihiro

Keisan Kogaku Koenkai Rombunshu (CD-ROM), 17, 4 Pages, 2012/05

Our goal is to evaluate the validity of results obtained from seismic simulation of entire nuclear plant, and then to estimate real behavior. In this study, we have established a trial tool to enable a zooming analysis from a combining analysis of ground-building-equipments (beam model) to an assembly structural analysis of equipments (solid model) in order to compare results of beam model and solid model. By applying the tool to analysis of a cantilever model with various cross sections, we have confirmed that results of solid model well coincide with theoretical solutions and results of beam model.

Journal Articles

Current status and future direction of full-scale vibration simulator for entire nuclear power plants

Uzawa, Ken; Watanabe, Tadashi; Nishida, Akemi; Suzuki, Yoshio; Takemiya, Hiroshi

High Performance Computing on Vector Systems 2011, p.171 - 184, 2012/01

The Center for Computational Science and E-systems (CCSE) has been promoting researches and developments for the full-scale 3D vibration simulator of an entire nuclear power plant, which is a virtual plant vibration simulator on inter-connected supercomputers. Application example of the vibration simulator to High Temperature Engineering Test Reactor (HTTR) and recent progress of collaborative work for JST-CREST program "Multiscale and multiphysics earthquake-proof simulation" are shown. This year, we started to implement the analysis capability of fluid effects to the vibration simulator. We have presented a two-phase flow model for analyzing a sloshing and suggested importance of turbulent effect to estimate the flow impact on the structure more precisely.

Journal Articles

Cerebral methodology based computing to estimate real phenomena from large-scale nuclear simulation

Suzuki, Yoshio

Proceedings of 19th International Conference on Nuclear Engineering (ICONE-19) (CD-ROM), 8 Pages, 2011/10

In nuclear field, it is indispensable to estimate real phenomena from simulations in order to improve the safety and security of nuclear power plants. Here, the analysis of uncertainty included in simulations is needed to reveal sensitivity of uncertainty due to randomness, to reduce the uncertainty due to lack of knowledge and to lead a degree of certainty by verification and validation (V&V) and uncertainty quantification (UQ) processes. To realize this, we propose "Cerebral Methodology based Computing (CMC)" as computing processes with deductive and inductive approaches by referring human reasoning processes. We have established its prototype system and applied it to a thermal displacement analysis of a nuclear power plant. The result shows that our idea is effective to reduce the uncertainty and to get the degree of certainty.

Journal Articles

Fault-tolerant mechanism of both job execution and file transfer for integrated nuclear energy simulation

Tatekawa, Takayuki; Teshima, Naoya*; Suzuki, Yoshio; Takemiya, Hiroshi

Progress in Nuclear Science and Technology (Internet), 2, p.591 - 597, 2011/10

By integrating simulation codes which simulate physical process or part of nuclear energy facility, large-scale and detailed simulation can be carried out. Such integrated simulations require several weeks or months of CPU times. Avoiding unscheduled outage of computers or network, we have developed fault-tolerant mechanism for cooperative execution of the codes. The mechanism covers abnormal end of jobs on supercomputers and error of file transfers. When the computer causes unexpected outage, the mechanism tries to submit job of simulation to alternative computer. Furthermore, by comparison the size of the files between before and after transfer, the mechanism detects error of the transfer. In the fault-tolerant mechanism, because the relations between the jobs and the file transfers are connected, we can decide an execution order of the codes by the definition of file flow. Therefore we can operate integrated simulations in which the codes are executed sequentially or concurrently.

Journal Articles

Full-scale 3D vibration simulator for an entire nuclear power plant on the simple orchestration application framework

Kim, G.; Nakajima, Kohei*; Teshima, Naoya*; Tatekawa, Takayuki; Suzuki, Yoshio; Takemiya, Hiroshi

Progress in Nuclear Science and Technology (Internet), 2, p.634 - 638, 2011/10

We developed grid-enabled application of full-scale 3D vibration simulator for an entire nuclear power plant on simple orchestration application framework (SOAF). The simulator is an analysis system to study seismic response of a whole digitalized nuclear power plant. In the simulator, components of a power plant are treated in hierarchical manner so that large components are grouped at primary level and small components such as pipes at secondary level. Boundary condition data are transferred from the primary level to the secondary level. SOAF provides functionality to enable users to simply define the data transfer in pipelined scenario which is technically difficult to realize using the existing grid technology. In this paper, we discuss technical issues of the realization of pipelined scenario on grid and demonstrate effectiveness of SOAF by analysis of High Temperature Engineering Test Reactor of JAEA using grid-enabled application implementing SOAF.

Journal Articles

Spatio-temporal mapping; A Technique for overview visualization of time-series datasets

Miyamura, Hiroko; Hayashi, Sachiko*; Suzuki, Yoshio; Takemiya, Hiroshi

Progress in Nuclear Science and Technology (Internet), 2, p.603 - 608, 2011/10

Numerical simulations have recently increased in scale and have often output high dimensional datasets. This makes it difficult for users to quickly grasp physical phenomena involved in such datasets. To overcome this difficulty, we propose a spatio-temporal mapping technique (spatio-temporal map) by using an information visualization technique. The spatio-temporal map is generated by mapping the values of a 3D and time-evolving physical quantity into a 2D space with spatial and temporal axes. Here, 3D spatial information is condensed into one dimension by subdividing a target model with an octree. By using the map, users can quickly find regions of interest (ROI). In addition, users can interactively change several aspects of the map such as its resolution and color coding method. By applying the spatio-temporal map to a full-scale 3D vibration simulator for an entire nuclear power plant, we confirmed that the map is a useful technique to quickly identify appropriate ROI.

Journal Articles

Visualization of blurry images of liquid by multi-scale analysis

Miyamura, Hiroko; Kureta, Masatoshi; Segawa, Mariko; Kubo, Jun*; Saito, Takafumi*; Suzuki, Yoshio; Takemiya, Hiroshi

Visualization of Mechanical Processes (Internet), 1(3), 8 Pages, 2011/10

The use of high frame rate neutron radiography has been proposed as a method for recording images of oil in a running car engine. However, it is difficult to capture the behavior of oil from such images, because the images are dark and blurry. Therefore, we attempt to overcome this problem using a multi-scale image processing technique, in which the oil regions are classified based on scale. This method can be used to focus attention on objects with a particular scale. In addition, we propose a technique by which to capture the time-dependent behavior of oil using spatio-temporal image analysis. Using these techniques, the region of interest can be determined and observed carefully.

181 (Records 1-20 displayed on this page)