Activity build-up and properties of oxide films on stainless steel samples at Loviisa unit 1

The extent of activity incorporation on primary circuit surfaces in a VVER plant is connected to the chemical composition of the coolant water and to the structure and properties of oxide films formed on material surfaces. Changes in operational conditions may induce changes in the structure of the oxide films and in the rate of activity incorporation. To predict these changes, experimental correlations between water chemistry, oxide films and activity incorporation, as well as mechanistic understanding of the related phenomena have been established. (R.P.)