1111 Computational Science and E-Systems Research
Computational Science Activity in Nuclear Energy Research and Development

Sustained performance(TFlops)

Seismic analysis

Nuclear Fusion

Nuclear Safety

Fukushima Reconstruction

Flow around oscillating pipe

R&D on Computational Science

Material degradation･Predicting degradation ofnuclear materials･Predicting physical propertiesof nuclear fuels･Seismic analysis

103102

Physical propertiesof nuclear fuels

101

100
102

K computer
BX900(JAEA)
103

104

105

Processors

Adsorption of radioactivematerials

Speed-up of plasma calculation

R&D on Computing Technology

Operation & Management･Visualization techniques･Parallel computation techniques･Supercomputer･Network system

Fig.11-1 Computational science activity in nuclear energy R&D
The CCSE unites computational science research, computing technology research, and computer operation and management,
and is creating cutting-edge knowledge and data in order to contribute to nuclear energy R&D and Fukushima reconstruction.

Computational science, which is known as the third type ofresearch methodology after the theoretical and experimental
approaches, is indispensable for understanding and predicting
phenomena that cannot be resolved theoretically because of theircomplexity and/or that are difficult to observe experimentally
because of cost and/or safety. Recently, the Ministry ofEducation, Culture, Sports, Science and Technology, which
recognized the importance of computational science, officiallyannounced a plan for developing a new supercomputer with acomputing speed 100 times faster than that of the K computer.
In addition, the news that China had successfully developed thefastest supercomputer in the world astonished the world. Suchunremitting progress in computers is based on a background ofincreasing importance for computational science.
The Center for Computational Science and E-Systems (CCSE)
manages and operates rapidly progressing supercomputersand promotes advanced research and development (R&D) on
computational science using them. It grapples with important
problems in nuclear energy R&D that require complicatedlarge-scale computation, such as material degradation by aging,
the high-temperature behavior of nuclear fuel, and evaluation of
the earthquake resistance of structures. Furthermore, to create
new knowledge about the mechanism of cesium soil pollution,
100

JAEA R&D Review 2013

the CCSE recently began a remarkable acceleration of advanced
R&D by computer simulation (Fig.11-1).
In Topic 11-1, which aims at understanding the degradation
mechanism of nuclear structural materials, the new conceptthat mobile hydrogen promotes crack growth is reported as afinding from a first principles calculation and thermodynamic
analysis. In Topic 11-2, the strange thermal conductivity
behavior exhibited by a new functional material, the topologicalsuperconductor, is introduced as a result obtained by a stateof-the-art computational science method. Topic 11-3 describes
R&D for the international thermal nuclear fusion reactor inwhich the computation speed of the code for predicting plasma
turbulence was materially improved using an innovative
calculation method. In Topic 11-4, the effect of pipe oscillationon coolant flow is estimated as an example of seismic analysis.
In Topics 1-5 and 1-19, the first principles calculation results
for understanding the cesium adsorption mechanism of clay
minerals and zeolites are reported as R&D for Fukushimareconstruction.
To contribute to Fukushima reconstruction and nuclear
energy R&D, the CCSE will develop a state-of-the-art computer
simulation technology as a key to resolving problems and strivecontinuously to be the leading force in computational science.