Profile

Outline

In Research Group for Nuclear Materials Modeling, the objective is to clarify the mechanisms and establish the prediction procedures for degradation phenomena of nuclear structural materials and fuels under combined environments by computational methods. We will construct the mechanistic models by comparison between multi-scale simulation and extremely precise experiments. In future, we aim to develop the next-generation nuclear structural materials and fuels by the simulation based on the models.

Reference
Y. Kaji et al., "Development of Stress Corrosion Cracking Model for Reactor Structural Materials", The 16th Pacific Basin Nuclear Conference, (2008)

Mechianisms of Intergranular Stress Corrosion Cracking and Development of Novel Crack Growth Model

Understanding the mechanisms of stress corrosion cracking (SCC), which often occurs at aged nuclear light water reactor, is exactly important in order to improve the accuracy of safety standard for aged nuclear plants. It is necessary to study on the mechanisms of SCC initiation and propagation. SCC initiation and propagation at nuclear structure are caused by various factors (stress, corrosion, thermal segregation, irradiation-induced segregation, cascade degradation, radicals in environment). Since degradation of the structural materials is induced by these complex environments, we need to consider these kinds of effects synthetically in order to clarify the mechanisms of SCC.

Novel Stress Corrosion Cracking Model and Crack Growth

Electronical Structure Analyses of Random Grain Boundary using Extended Semi-Empirical Molecular Orbital Method

Electronic Structure and Chemical Reaction of Transition Metal Clusters

Atomistic simulations of defect dynamics in nuclear materials

Damage Evaluation for the Structural Materials in Power Plant

Electronical Structure Analyses of Nuclear Fuels Including Minor Actinide Elements

Nuclear wastes from nuclear power plants contain minor actinide (MA), and the radiotoxicity of MA is a important subject. As one of the technologies to reduce this radiotoxicity of MA to natural environment, oxide and nitride fuels containing MA are proposed, and it is necessary to evaluate various properties of these fuels.

We are analyzing the X-ray absorption near-edge structure (XANES) of Am oxides that has been measured as the basic data as to the development of Am containing mixed oxide (Am-MOX) fuel, which is one of the fuels containing MA, using the first principles calculation. As for nitride fuels containing MA, we are predicting various properties of actinide nitrides from the view point of electronic structure and analyzing chemical reactions, using the first principles calculation.

X-ray absorption spectra measurement and analysis with the first principles calculation for Americium oxide

First principles study on electronic structure, mechanical and thermal properties of actinide nitrides