We present an approach to determine the sensitivity of irradiation damage accumulation to the irradiation dose rate in polycrystalline systems, when the internal and boundary sink strengths are the only microstructural components affecting defect accumulation. A rate theory of defect removal is introduced, and suggests that the impact of the irradiation rate on damage accumulation depends on the ratio of internal sink strength to the grain boundary sink strength. The validity of the model is tested with two different methodologies: i) proton irradiation of coarse grain commercial alloy, Zircaloy-4 and ii) atomistic simulation of electron irradiation of nano-size pure zirconium. In case (i), the removal of defects at the grain boundary is negligible, and the sensitivity to irradiation rate is minimal. In case (ii), defect annihilation at the boundary dominates. In that scenario, if the grain boundary density increases by a factor n, the irradiation rate should increase by a factor n² times in order to achieve equivalent steady state damage accumulation.

当内部和边界沉陷强度是影响缺陷累积的唯一微结构成分时，我们提出一种确定辐照损伤累积对辐照剂量率的敏感性的方法。介绍了一种缺陷去除率理论，并提出了辐照速率对损伤累积的影响取决于内部沉陷强度与晶界沉陷强度的比值。该模型的有效性通过两种不同的方法进行了测试：i）质子辐照粗粒商品合金Zircaloy-4的质子辐照，以及ii）纳米级纯锆电子辐照的原子模拟。在情况（i）中，在晶界处的缺陷的去除可忽略不计，并且对照射速率的敏感性最小。如果（ii），边界处的缺陷an灭占主导地位。在那种情况下，如果晶界密度增加一个因子n，辐照率应增加n倍²倍，以达到等效的稳态损伤累积。