Effect of Zn Addition on Behavior of Deposited Co in Oxide Scales of Alloys in PWR Primary Water

In order to simulate the deposition of Co oxide on the surface of PWR structural materi- als during service, oxide scales doped with Co on stainless steels 316 and 304, and alloy 690 were prepared by soacking them in a high temperature solution containing Co ions. Then the effect of Zn addition on the behavior of the deposited Co in oxide scales was studied in a simulated PWR prima- ry water with Zn addition at 315 ℃. The results show that the presence of Co changes the morphol- ogy of oxide scales, while in the simulated PWR water the added Zn may displace the deposited Co in the oxide scales.