Advanced Computational Materials Science: Application to Fusion and Generation IV Fission Reactors (Workshop Report)

Primary Radiation Damage Formation

“…To date, there have been a limited number of studies carried out to investigate whether and how primary damage formation would be altered in nanograined metals, [116][117][118][119][120][121] and quite strong effects have been observed. 116 The work from Stoller and coworkers 122 will be used here to illustrate the phenomenon because the results of that study can be directly compared with the existing single crystal database that has been discussed above. A sufficient number of simulations were carried out at cascade energies of 10 and 20 keV and temperatures of 100 and 600 K to obtain a statistically significant comparison.…”

“…More details on the procedure can be found in Stoller and coworkers. 122 The system was equilibrated for over 200 ps including a heat treatment up to 600 K. Figure 29 illustrates a typical grain structure with each grain shown in a different color. The approximate sizes of 5 and 20 keV cascades have been projected on to the face of the simulation cell.…”

“…It was common for the cascade volume to cross from one grain to another. 122 The number of vacancies and interstitials surviving in the nanograin simulations is compared to the single crystal results in Figure 30. A wider range of cascade energies is included in Figure 30(a) to show the trend in the single crystal data, while Figure 30(b) highlights the differences at the temperature and energy of the nanograin simulations.…”

Million-atom molecular dynamics simulations of magnetic iron

“…The development of a good understanding of magnetic properties of dislocations and other defects is essential for modelling mechanical properties of magnetic materials, as well as for modelling microstructural evolution of iron-based alloys and steels under irradiation. For example, in a recent comprehensive review of the currently available modelling methodologies [11] it was noted that '...the absence of a physically sensible treatment of magnetization points to more fundamental problems in the many-body potential concept'. The need to develop a local representation of magnetic effects consistent with the treatment of interatomic forces comes from the fact that it is only a local model that is able to describe an interstitial atom defect or an edge dislocation, where the level of local deformation approaches $15% [12].…”

An Assessment of Radiation Damage Models and Methods

“…In a broader context, materials needs for Gen-IV reactors have been analyzed and compared to corresponding needs for fusion reactors and spallation neutron sources in Ref. [5], and the issue of materials modeling for fission and fusion reactors has been the subject of other reports [6,7]. The current report has drawn from all these resources in formulating the recommendations made in the final section.…”