Multi-scale modelling of Refractory High-Entropy Alloys materials for Small Modular Reactors

smr通常预期的输出功率小于300兆瓦（电）或小于1000兆瓦（热）。它们有许多优点，比如占地面积相对较小、资本投资较少、选址在大型核电站无法达到的位置，以及提供增量电力补充。在运行过程中，反应堆压力容器材料暴露在超过1000°C的高温、辐射和腐蚀中，导致容器和反应堆堆芯焊缝局部脆化。由于反应堆容器被认为是不可替代的，这些苛刻的操作环境需要开发新的合金材料，以承受其增加的物理，化学，热和辐射相关的挑战，以及计算方法来预测其在操作条件下的行为。高熵合金（HEAs）是一个很有前途的选择，因为它们的成分可以在很大范围内进行调整，以优化高温机械性能、辐射和耐腐蚀性，并获得比传统材料更好的性能。然而，与传统合金相比，目前对HEAs性能的了解仍然不够先进，需要进一步的研究来评估它们提供的机会。耐火HEAs （RHEAs）由于其在高温下保持机械性能，减少缺陷产生以及抗辐照引起的膨胀和硬化而受到核学界的特别关注。然而，由于缺乏计算，这些观察结果背后的机制仍然没有得到很好的理解。在这方面，拟议的研究活动将为HEAs开发相场晶体（PFC）模型，以了解它们的性质以及环境退化机制。除了为SMRS船体设计新材料外，我们的研究结果还将提供有价值的信息，可以提高系统、结构和部件在正常、异常和长期运行期间的可靠性。

SMRs are typically anticipated to have an electrical power output of less than 300 MWe (electric) or less than 1000 MWth (thermal). They offer many advantages, such as relatively small physical footprints, reduced capital investment, the ability to be sited in locations not possible for larger nuclear plants, and provisions for incremental power additions. During operation, the reactor pressure vessel material is exposed to high temperatures exceeding 1000°C, radiation, and corrosion, resulting in localized embrittlement of the vessel and welds in the reactor core. As the reactor vessel is considered irreplaceable, these demanding operating environments require the development of new alloy materials that can withstand their increased physical, chemical, thermal, and radiation-related challenges, as well as computational approaches to predict their behavior under operation conditions. High Entropy Alloys (HEAs) are a promising option, due to their composition which can be tuned over a wide range of possibilities to optimize high-temperature mechanical properties, radiation, and corrosion resistance, and obtain improved performances compared to conventional materials. However, current knowledge of HEAs properties is still less advanced compared with conventional alloys, and further studies are needed to assess the opportunities they offer. Refractory HEAs (RHEAs) are of particular interest to the nuclear community due to their retention of mechanical properties at high temperatures, reduced defect production, and resistance to irradiation-induced swelling and hardening. However, the mechanism behind these observations is still not well understood because of the lack of computational. In this regard, the proposed research activity will develop a Phase Field Crystal (PFC) model for HEAs to understand their properties as well as environmental degradation mechanisms. In addition to the design of new materials for the body of the SMRS vessel, our result will provide valuable information that can improve the reliability of systems, structures, and components during normal, abnormal, and long-term operations.