Ponente
Descripción
Sergei L. Dudarev
UK Atomic Energy Authority, Culham Campus, Abingdon, Oxfordshire OX14 3DB, United Kingdom
Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
Multiscale models for nuclear materials have now become sufficiently advanced to enable simulations of microstructures of irradiated materials at the level of fidelity, where predictions, derived from models involving no adjustable parameters, can be quantitatively compared with experimental observations. Defect and dislocation microstructures predicted by simulations, have recently been compared with transmission electron microscopy images, X-ray diffraction, Rutherford backscattering spectroscopy and hydrogen desorption spectroscopy measurements, producing surprisingly favourable outcomes. The results extended beyond the interpretation of observations, leading to fundamentally new insights into microstructural processes driven by impacts of energetic particles. Models for radiation effects have also been extended to reactor component scale, providing a foundation for the holistic assessment of materials performance in an operating fusion power plant.
The availability of an intense source of neutrons, with the spectrum matching that of the D-T fusion plasma, provides new opportunities for testing and developing materials, extending the capabilities provided by ion and fission irradiation experiments and broadening the range of testing conditions, to match the fusion power plant conditions. Full tokamak simulations are already able to define the spectrum of mechanical stress and irradiation doses expected at various spatial locations in an operating fusion tokamak, with further effort aiming at providing a quantitative definition of dynamically evolving space of operating conditions for materials in a fusion device. Presently available literature data provide only highly approximate estimates, whereas engineering design studies require a database detailing the evolution of materials in a multi-dimensional space of environmental variables including the neutron irradiation dose rate, time, temperature, tensorial stress, hydrogen isotope atmosphere, generation of transmutation elements, interaction with coolants, corrosion, occurrence of transients etc.
The presentation outlines the areas, where combining DONES capabilities with predictive materials simulations might prove most impactful, offering a comprehensive view of materials testing and validation, linked to reactor design studies and involving the assessment of data derived from complementary ion irradiation and fission reactor irradiation experiments.