Effect of dpa rate on the temperature regime of void swelling in ion-irradiated pure chromium

Pure chromium is a promising candidate for coating of Zircalloy fuel rods in light water-cooled power reactors to avoid or delay hydrogen generation in accident scenarios. Void swelling of chromium is one possible contributor to coating-interface failure and needs to be studied. The effect of dpa rate on void swelling of Cr was studied using 5 MeV Fe ion irradiation to 15 peak dpa at peak dpa rates of 3.5 x 10(-5), 3.5 x 10(-4), and 3.5 x 10(-3) dpa/s, at six temperatures between 350 degrees C and 650 degrees C. The post-transient (steady-state) swelling rate of pure Cr is similar to 0.05%/dpa. Swelling in Cr also appeared to start at a much higher swelling rate at very low doses. The observed dependence of peak swelling temperature on dpa rate agrees well with earlier theoretical models and clearly demonstrated the well-known temperature shift phenomenon. After determination of the peak swelling temperatures under ion irradiation at three dpa rates we extrapolated downwards to dpa rates characteristic of both sodium-cooled fast reactors and light water-cooled reactors. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study investigates the effect of dpa rate on void swelling of pure chromium and observes the dependence of peak swelling temperature on dpa rate, providing temperature predictions.