Water chemistry in EdF PWRs

Electricite de France (EdF), with more than 40 operating pressurized water reactor (PWR) units, has established its own chemistry guidelines in order to: (1) keep activity low because of corrosion products in the primary coolant; (2) prevent serious corrosion problems, particularly on the secondary side of steam generator tubes; (3) maintain a high availability factor; and (4) minimize the cost of maintenance. The specifications are mainly based on controls with on-line monitors, which give reliable indicators, an immediate response in the control room in case of significant pollution, and a more precise trend for low deviations. They are completed by analyses on grab samples for specific controls and diagnoses