Multiscale-Multiphysics Modeling of Radiation-Damaged Materials: Embrittlement of Pressure-Vessel Steels

Abstract

Radiation damage, and its attendant effect on a wide spectrum of materials properties, is a central issue in many advanced technologies ranging from ion-beam processing to the development of fusion power. Indeed, the various challenges presented by irradiation effects are too numerous to discuss in this brief article.

Roadmap for Nondestructive Evaluation of Reactor Pressure Vessel Research and Development by the Light Water Reactor Sustainability Program

“…The surveillance capsules are irradiated at somewhat higher flux than the RPV and are withdrawn periodically to test the specimens and determine the TTS vs neutron fluence. The results are compared with the predictive model in US Nuclear Regulatory Commission (NRC) Regulatory Guide 1.99, Revision 2 [30] and with 10 CFR 50 [31]. Currently, the irradiation-induced shift of the fracture toughness is assumed to be the same as the CVNbased TTS.…”

“…Well-formed copper-rich precipitates (CRPs), composed of Cu, Ni, Mn, and Si, form above a threshold level of about 0.07 wt % Cu. At high concentrations of these alloying elements, the Mn, Ni, and Si content in the precipitates can exceed the corresponding Cu content [27][28][29][30][31], in which case they are sometimes referred to as MNPs. However, for simplicity and clarity, we will refer to all precipitate features in steels with at least 0.07 wt % Cu as CRPs throughout this document.…”

“…Evolution of CRPs is the dominant embrittlement mechanism in the most irradiation-sensitive western Cu-bearing RPV steels [27][28][29][30][31] . The MFs provide a secondary contribution in this regime but may exceed the CRP contribution at high fluence, especially at lower Cu levels.…”

“…The MFs provide a secondary contribution in this regime but may exceed the CRP contribution at high fluence, especially at lower Cu levels. In very high-Cu steels, there is a maximum amount of Cu remaining in solid solution that is available for radiation-enhanced precipitation (0.25 to 0.3 wt %), due to pre-precipitation during RPV heat treatments [27][28][29][30][31][32][33][34], regardless of bulk Cu content. The rate of CRP nucleation depends on the alloy Cu content (as well as other elements) and irradiation temperature, but it is generally very rapid due to the large supersaturation of this solute in higher Cu steels.…”

Multiscale Materials Modeling of Structural Materials for Next Generation Nuclear Reactors

“…Pertinent processes span more than 10 orders of magnitude in length from the sub-atomic nuclear to structural component level, and span 22 orders of magnitude in time from the sub-picosecond of nuclear collisions to the decade-long component service lifetimes (Odette, Wirth et al 2001;Wirth, G.R. et al 2004).…”