Inhibition of moderator graphite corrosion in CEGB Magnox reactors

The requirement for inhibition of moderator corrosion in CEGB Magnox reactors is considered, and experimental injections of hydrogen into an operating reactor at Wylfa are described. The coolant chemistry of the reactor is discussed with respect to the kinetics of methane and water formation. The reduction in the rate of graphite corrosion following hydrogen injection is shown to agree well with the laboratory data and with operational data from other reactors. The reactor information, together with the laboratory data, will allow the optimum hydrogen concentration to be defined for further operation of the Board's reactors. (author)