Human resource development related to remote control technology for monitoring inside RPV pedestal during retrieval of fuel debris (Contract research); FY2019 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; The University of Tokyo*

JAEA-Review 2020-028, 68 Pages, 2021/01

JAEA-Review-2020-028.pdf:4.01MB

The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2019. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Human Resource Development Related to Remote Control Technology for Monitoring Inside RPV Pedestal during Retrieval of Fuel Debris". This study deals with construction of a monitoring platform for understanding the status inside a reactor during fuel debris removal, and measurement and visualization by sensors moving on the platform. In addition, to develop research personnel through research education by participating in such research projects, classroom lectures, and facility tours is also a goal of this project. In FY2019, the main activities were conceptual design, prototyping, and conceptual planning.

Image-based view selection for shape comparison of mode water regions in virtual reality spaces

Yano, Midori; Ito, Takayuki*; Tanaka, Yusuke*; Matsuoka, Daisuke*; Araki, Fumiaki*; Czauderna, T.*; Stephens, K.*

Proceedings of Joint International Conference on Supercomputing in Nuclear Applications + Monte Carlo 2020 (SNA + MC 2020), p.201 - 208, 2020/10

Visual analysis plays an important role in understanding and evaluating the climate models, their variables, and their outputs because complex processes are required for the tuning of the climate models. Virtual Reality (VR) technologies are effective for 3D visualization and have been recently employed for visual analysis of more various scientific data. However, researchers may have some problematic situations while using VR space depending on user operations and target geometries. Here, we propose an image-based view selection method to solve these situations and understand differences in ocean states between simulations and observations based on shapes of mode water regions. This view selection takes evaluation criteria for shape comparison of mode water regions generated from simulations and observations into account. This paper introduces two example cases applying this view selection and discusses on a degree of shape matching of mode water regions of each case.

Evaluation growing and collapsing behaviors of cavitation bubbles under flowing condition

Kawamura, Shunsuke; Naoe, Takashi; Ikeda, Tsubasa*; Tanaka, Nobuatsu*; Futakawa, Masatoshi

Advanced Experimental Mechanics, 4, p.33 - 37, 2019/08

A mercury enclosure vessel made of stainless steel is used as a spallation target in the pulsed spallation neutron source at J-PARC. It is severely damaged by the cavitation induced with pressure waves in association with the pulsed proton beam injection. A double-walled structure with a narrow mercury channel was adopted in the front end of the target vessel to reduce the cavitation damage. It has been experimentally demonstrated that the cavitation damage could be mitigated in the narrow channel but its mechanism has been unclarified yet. In this study, we investigated the cavitation from growing to collapsing through visualizing the spark-induced cavitation bubbles under flow field using a high-speed video camera. Furthermore, we measured the wall vibration due to the cavitation bubble collapse with changing flow velocity parametrically. It was found that the microjet collided perpendicular to the wall in the stagnant flow condition while it collided with an inclined angle from the perpendicular direction, suggesting that the collision pressure on the wall was reduced by flowing.

Visualization of fractures in an Excavation Damaged Zone in the Horonobe Underground Research Laboratory (Joint research)

Aoyagi, Kazuhei; Chen, Y.*; Sakurai, Akitaka; Ishii, Eiichi; Ishida, Tsuyoshi*

JAEA-Research 2017-014, 49 Pages, 2018/01

JAEA-Research-2017-014.pdf:16.29MB

In this research, we performed the resin injection experiment at the 350 m gallery of the Horonobe Underground Research Laboratory in order to identify the three dimensional distribution of fractures induced around the gallery owing to excavation. To this end, the low viscosity resin mixed with a fluorescent substance was developed and applied to the in situ resin injection experiment. As a result, the resin was successfully penetrated into the fractures around the gallery without disturbing their situation and then fixed within them. After the experiment, the rock cores around the injection borehole were drilled for the observation. The observation under ultraviolet light revealed that the extent of the development of fractures was about 0.9 m into the borehole wall. In addition, the aperture of the fractures distributed within 0.3 m from the gallery wall was ranged 1 to 2 mm, and that distributed from 0.3 to 0.9 m was less than 1 mm. On the other hand, in the borehole televiewer (BTV) survey, only one fracture within 0.2 m from the wall could be detected owing to the resolution of the survey system. Thus, it is expected that the BTV survey underestimate the extent of the development of fractures.

Interactive visualization for singular fibers of functions :

Sakurai, Daisuke; Saeki, Osamu*; Carr, H.*; Wu, H.-Y.*; Yamamoto, Takahiro*; Duke, D.*; Takahashi, Shigeo*

IEEE Transactions on Visualization and Computer Graphics, 22(1), p.945 - 954, 2016/01

https://doi.org/10.1109/TVCG.2015.2467433

Scalar topology in the form of Morse theory has provided computational tools that analyze and visualize data from scientific and engineering tasks. Contracting isocontours to single points encapsulates variations in isocontour connectivity in the Reeb graph. For multivariate data, isocontours generalize to fibers inverse images of points in the range, and this area is therefore known as fiber topology. However, fiber topology is less fully developed than Morse theory, and current efforts rely on manual visualizations. This paper therefore shows how to accelerate and semi-automate this task through an interface for visualizing fiber singularities of multivariate functions : . This interface exploits existing conventions of fiber topology, but also introduces a 3D view based on the extension of Reeb graphs to Reeb spaces. Validation of the interface is performed by assessing whether the interface supports the mathematical workflow both of experts and of less experienced mathematicians.

Development of software tools for 4-D visualization and quantitative analysis of PHITS simulation results

Furutaka, Kazuyoshi

JAEA-Data/Code 2014-027, 32 Pages, 2015/02

JAEA-Data-Code-2014-027.pdf:7.25MB

A suite of software tools has been developed to facilitate the development of apparatus using a radiation transport simulation code PHITS by enabling 4D visualization (3D space and time) and quantitative analysis of so-called dieaway plots. To deliver useable tools as soon as possible, the existing software was utilized as much as possible; ParaView will be used for the 4D visualization of the results, whereas the analyses of dieaway plots will be done with ROOT toolkit with a tool named "diana". To enable 4D visualization using ParaView, a suite of tools (angel2vtk, DispDCAS1, CamPos) have been developed for the conversion of the data format to the one which can be read from ParaView and to ease the visualization.

Report on processing speed for visualization of large-scale data

Hoshi, Yoshiyuki; Kume, Etsuo

JAERI-Data/Code 2005-010, 48 Pages, 2005/09

JAERI-Data-Code-2005-010.pdf:8.7MB

In scientific and engineering calculations, recently, computational sizes and amounts of calculated results have been increased rapidly due to speedup of computers and increase in memory size. Post processing or visualization of a huge amount of numerical data plays a very important role for understanding the meaning of the data. Computational loads for visualization of large-scale data are still heavy even for graphic computers. Processing speeds for visualization of large-scale data are measured using general-purpose visualization software on graphic computers in JAERI. A guideline is summarized in this report to choose appropriate graphic computers according to the size of the data.

User guide of AVS/ITBL for numerical environmental system

Suzuki, Yoshio; Matsumoto, Nobuko*; Yamagishi, Nobuhiro*; Arakawa, Takuya*; Kuraishi, Hideaki*

JAERI-Data/Code 2004-013, 163 Pages, 2005/02

JAERI-Data-Code-2004-013.pdf:33.81MB

The Center for Promotion of Computational Science and Engineering of the Japan Atomic Energy Research Institute has carried out the ITBL (Information-Technology Based Laboratory) project which is one of e-Japan priority policy programs. AVS/ITBL is the visualization tool which has been developed aiming at realizing the efficient visualization in the ITBL environment. This visualization tool is one of the tools of ITBL infrastructure software and operates in cooperation with AVS/Express. In this paper, utilization of AVS/ITBL to the numerical environmental system, which is one of the applications in ITBL project, is presented. And the outline of the operation in this utilization is indicated.

Research and development of the visualization grid in ITBL project

Takeshima, Yuriko; Suzuki, Yoshio*; Matsumoto, Nobuko*; Sai, Kazunori*; Nakajima, Norihiro

Proceedings of 4th International Symposium on Advanced Fluid Information and Transdiciplinary Fluid Integration (AFI/TFI 2004), p.157 - 158, 2004/11

The Information-Technology-Based Laboratory (ITBL) project aims to construct a virtual research environment which shares intellectual resources such as the super computers by the grid computing, softwares and data in Japan and supports joint researches at a distance. In the project, two visualization systems: the PATRAS/ITBL and the AVS/ITBL have been developed. The feature of the PATRAS/ITBL is the collaborative, real-time visualization of data resulting from an execution of numerical simulations. The AVS/ITBL visualization system enables remote postprocessing visualization of any data stored on any supercomputer located in the ITBL network. The global structure and technologies of these systems are presented.

("3D"+"2D+Time") visualization of vapor/water in the reactor observed by neutron beam

Kureta, Masatoshi

VizJournal, (11), 5 Pages, 2004/06

This paper explains the neutron radiography thermal-hydraulic measurement technique, especialy visualization technique, which was developed at Japan Atomic Energry Research Institute. Observation of large and fine-mesh data obtained by the new measurement technology is important from a research point of view. We developed the advanced visualization software which puts into practice effective observation by using new visualization methods, and we made the vizualization of phenomena possible by using VR and/or animation displays etc. by this system. Especially in this paper, the visualization techniques which were used in a prize-winning work of the "Visual Sience Festa 2003" by NIKKEI SCIENCE as easy to read for a general reader as possible by using many figures and movies.