Radiation-induced embrittlement of nuclear steels is one of the main limiting factors for safe long-term operation of nuclear power plants. In support of accurate and safe reactor pressure vessel (RPV) lifetime assessments, we developed a physics-based model that predicts RPV steel hardening and subsequent embrittlement as a consequence of the formation of nano-sized clusters of minor alloying elements. This model is shown to provide reliable assessments of embrittlement for a very wide range of materials, with higher accuracy than industrial correlations. The core of our model is a multiscale modelling tool that predicts the kinetics of solute clustering, given the steel chemical composition and its irradiation conditions. It is based on the observation that the formation of solute clusters ensues from atomic transport driven by radiation-induced mechanisms, differently from classical nucleation-and-growth theories. We then show that the predicted information about solute clustering can be translated into a reliable estimate for radiation-induced embrittlement, via standard hardening laws based on the dispersed barrier model. We demonstrate the validity of our approach by applying it to hundreds of nuclear reactors vessels from all over the world.

核钢辐射脆化是核电站长期安全运行的主要限制因素之一。为了支持准确和安全的反应堆压力容器 (RPV) 寿命评估，我们开发了一个基于物理的模型，该模型可以预测 RPV 钢硬化和随后的脆化，这是形成纳米级微量合金元素簇的结果。该模型被证明可以为非常广泛的材料提供可靠的脆化评估，其准确性高于工业相关性。我们模型的核心是一个多尺度建模工具，可以根据钢的化学成分及其辐照条件预测溶质聚集的动力学。它是基于观察到溶质簇的形成是由辐射诱导机制驱动的原子传输引起的，这与经典的成核和生长理论不同。然后，我们表明，通过基于分散屏障模型的标准硬化定律，可以将有关溶质聚集的预测信息转化为辐射诱发脆化的可靠估计。我们通过将其应用于来自世界各地的数百个核反应堆容器来证明我们方法的有效性。