Interaction of Oxide Layers on Structural Materials with Light Water Reactor Coolants - its influence on the mechanism of oxide growth and restructuring

Abstract

This chapter presents a study, which examines the interaction of oxide layers on structural materials with light water reactor coolants and its influence on the mechanism of oxide growth and restructuring. The results show that the growth and restructuring of the barrier and inner oxide sublayers on stainless steel in high-temperature water is determined mostly by kinetics and solid-state transport. The interaction of coolant-originating species with these two layers can be treated also as a solid-state process. The outer layer growth is governed by the stability of the oxide phases formed, and the incorporation of foreign species in them involves surface complexation and reprecipitation reactions. It is suggested that the data on the interaction of oxides with such species can provide an additional way to estimate the kinetic and transport parameters of oxide growth on construction materials in light water reactor primary circuits.