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Tomas Lazauskas, Zainab Al-Tooq, Roger Smith, Steven Kenny Loughborough University Metals used in fission reactors experience extreme conditions during service, such as high temperature, corrosive and radiation environments. These effects occur over very long time scales. A typical reactor lifetime is ~ 40 years with the maximum number of displacements per atom induced by the radiation being of the order of 0.05 in the region next to the reactor core. During a radiation event a fast process (a collision cascade) occurs which produces defects, i.e. vacancies and interstitials but these diffuse over much longer time scales. Our group focusses on performing simulations using a combination of Molecular Dynamics (MD) to model the collision cascade and an on-the-fly Kinetic Monte Carlo (otf-KMC) technique to investigate the diffusive processes that occur well beyond the time scales accessible by Molecular Dynamics Using this technique allows typical radiation dose effects to be investigated. Examples are presented for potential next generation reactor materials such as Ni-Cr alloys and oxide dispersion strengthened (ODS) steels with 0.3 at% embedded yttria nanoparticles. Interfaces will be shown to play an important role in the defect trapping process. |
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