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Role and Potential of Nuclear Computational Science

Nuclear Fusion

Nuclear Reactor

High-intensity Proton Accelerator
dislocation

Extension to Project Research
Nuclear Fusion
Nuclear Reactor
High-intensity Proton Accelerator

Seismic Analysis

SP

Aged Material Deterioration

R&D for Computational Science
Seismic Analysis, Nuclear Material
Property Analysis, Prediction, etc.

R&D for Computer Science
Large-scale Parallel Computing, Visualization,
Large data processing, etc.

Radioactive Substance
Absorption

Operation & MaintenanceSupercomputer, Network

Visualization
Radiation Dose Database࡮
Distribution Map
Enhancement and Reinforcement of University-Industry Research Collaboration
Promotion of the Combination of Facilities and Equipment

Fig.11-1 Development of nuclear computational science research in JAEA
Nuclear computational science research is utilized not only for research projects in JAEA but also for the enhancement andreinforcement of university-industry research collaboration. In addition, we are promoting its application to research and development
for Fukushima support.

Computational science is the third research methodology,
following theory and experiment, and has maderemarkable progress by becoming a field that is indispensablefor the elucidation and prediction of phenomena difficult toobserve or replicate in experiments. The next-generation
supercomputer K was developed as a national project andhas begun to be used. A change in the environment
surrounding computational science has allowed its growth toaccelerate.
We study important issues in the nuclear field, including
those related to earthquake-resistance strength and deteriorationof aged material, which cannot be sufficiently investigatedwithout making full use of advanced computational
technology, as shown in Fig.11-1. In addition, we areinvolved in various research and development activities andwe develop and maintain the super-large-scale parallel
computational technology required as a generic technology
for such research. We ensure that the results of this researchsupport broad research themes, such as fast reactor or nuclear
fusion research, and allow for further development in this field.
The elucidation of the mechanism and the prediction of thedeterioration of nuclear reactor structure materials areimportant problems faced in the research on aged material
deterioration. Therefore, it is necessary to predict thesegregation of atomic impurities that lower the material
strength. In Topic 11-1, we introduce an example study that
evaluates the segregation quantity at the grain boundary ofphosphorus in irradiated materials by solving the diffusion
rate equation using the coefficient obtained by the firstprinciples calculation.

In the research cooperation with the Quantum Beam
Science Directorate, it is an important problem to analyze thedata for the neutron dispersion strength of an iron-based hightemperature superconductor observed in J-PARC and toelucidate the superconducting structure. We introduce a
research example of a virtual experiment on a scale that only
a supercomputer can handle using the modeling by the firstprinciples calculation in Topic 11-2.
In the earthquake-resistance research for nuclear facilities,
improving the precision to simulate the dynamic behavior ofan extra-large earthquake is an important problem. First, it isimportant to model the elastic-plastic behavior of aconnection and the neighborhood structure expected toachieve the plastic state. In Topic 11-3, we introduce one of
the research examples of the elastic-plastic modeling of theconnections between a nuclear building and the equipment.
In the Fukushima support, we build a database that canmanage the radiation dose measurement results and adistribution map system that can confirm them on a map
based on the accident at the Tokyo Electric Power Company,
Incorporated Fukushima Daiichi Nuclear Power Station, incooperation with the Fukushima Environmental Safety
Center, and make this available to the public. In Topic 1-3,
we summarize these systems.
In future, we will continue to work hard on nuclear
research and development utilizing advanced computational
science and generic computer technology. We will also
deepen our cooperation with organizations inside and outside
JAEA as we progress in the field of nuclear computational
science research.
JAEA R&D Review 2012101