Various attempts have been made to identify chemi­cals which will either inhibit the extent of corrosion beyond the required passivation layer, or selectively, inhibit the mechanism of corrosion product release by modifying the structure and adherence of the oxide film. A further possibility is the use of chelating re­agents to continuously and selectively remove active species by dissolution from deposited material and oxide films. Such soluble species could then be re­moved on an ion exchange bed possibly with regenera­tion of the chelating agent.

Both of these approaches are under development and will have to be proved effective and acceptable to the existing complex primary circuit chemistry be­fore they can be recommended for use by reactor operators.