• Bojinov, Martin
• Mäkelä, Kari
• Olin, Markus
• Sten, Pekka
• Laitinen, Timo
• Saario, Timo
• Lehikoinen, Jarmo

Abstract

Due to the exposure to the aqueous coolant, thecomponents of the primary circuit in a nuclear powerplant oxidise, resulting both in the formation of anoxide film on the component surfaces and in the releaseof soluble metal ions. The properties of the oxide filmsare likely to have a significant effect on the corrosionsusceptibility as well as on the rate at whichradioactive nuclei are incorporated on the componentsurfaces from the coolant. The latter phenomenon has amarked effect on the occupational dose rates, especiallyduring annual outages. This work aims at understandingthe properties and behaviour of oxide films in differentcoolant conditions and thus at predicting the risks forcorrosion and activity build-up. The approach chosen isto investigate and model separately the phenomena takingplace at the film/solution interface, in the outer,porous part of the oxide film and in the inner, compactpart of the film. In addition, a significant contributionis paid to the development of electrochemical techniquescapable of operating in high-temperature environmentswith even extremely low conductivity. This reportsummarises the progress made during the first two yearsof the project.

Topics

• porous
• surface