3. Instrumentation and explanations for the main circuits

3.1 Principle of automatic chemical monitoring

The number and nature of ongoing inspections may vary significantly from one operator and country to another, depending in particular on regulatory requirements and differences in plant design or specific features.

The basic system for continuous monitoring of the main chemical parameters of a 900 MWe PWR reactor on a French riverside comprises 30 to 40 PLCs. This "base" is supplemented by PLCs for demineralized water production, discharge and environmental monitoring, as well as site-specific PLCs for monitoring condenser and air cooler scaling, and anti-amoebic vaccination of the tertiary circuit.

The chemical measurements carried out on French PWR-type power plants generally address concerns...