Corrosion products behavior in primary circuit of PWR: cobalt and nickel sorption onto model ferrites

The corrosion of the metal parts in the primary circuit of PWR leads to the release of metal oxides particles and ionic species. These corrosion products circulate through the primary circuit and may be activated when they pass through the core. The deposition of the activated particles in areas out of flux is then responsible for surface contamination. These particles can also interact with the ionic species in the primary medium, contributing to their transport and to their deposition on surfaces outside the flux. In order to have better contamination control, characterization (specific surface, sire, PZC...) of different particles of primary circuit and study of their interaction with soluble species and surfaces (adhesion, sorption...) is necessary. Species take into account in this study are for particles: nickel and cobalt ferrites and magnetite, for primary circuit materials: Inconel 690, Zircaloy 4 and stainless steel 304L. Cobalt and nickel sorption, main responsible of primary circuit contamination, on several corrosion products were experimentally realized and modelized with ECOSAT code. Surface charge were also studied. Data obtained will be introduced in different calculation code in order to modelized contamination in primary circuit under dynamics conditions. (author)