Research on corrosion release model for nuclear metallic materials based on PBR

Abstract

BackgroundThe metallic materials utilized for nuclear reactors undergo corosion due to the inherient high-temperature and high-pressure environment. Consequently, the corrosion products may be deposited in the core, called crud, and impact the fuel operation, core reactivity, and primary radioactivity, such as crud-induced localized corrosion or crud-induced power shift.PurposeThus, this study aimed to establish a model that can quantitatively analyze these corrosion products, the results of which can then be used to evaluate the impact of these products.MethodsBased on the corrosion and release dynamic theory, combined with the assumption of metallic oxide volume ratio (Pilling-Bedworth Ratio), a corrosion and release model of metallic materials was developed. The model was validated based on experimental data from Inconel 690.ResultsThe verification result indicates that the proposed model is reasonable and scientific, and hence can be used to quantify the amount of main corrosion and release products of metallic materials for nuclear reactors.ConclusionsThis study provides a model of the main elements of corrosion products including Ni and Fe ferrite for PWR plants, which can be used for evaluating the impact of corrosion products. However, some of the microelements of corrosion cannot be quantified by using this model as the corresponding equations were over-determined. Hence this aspect requires further research in the future.

Keywords

• metallic materials for nuclear reactors
• corrosion and release model
• deposited
• verification
• pbr