Stringent requirements to ensure electricity supply

As the primary supplier of electricity in France, the nuclear power plant fleet must be able to generate baseload electricity for business and residential customers throughout the year. To achieve this, EDF has set stringent requirements for availability, safety and maintenance.

Improving fleet availability

To meet electricity demand during periods of peak consumption, EDF makes it an operating priority to improve the availability of its nuclear fleet. The goal is to keep availability at a high level in order to meet peak demand, especially in the winter months. For several years now fleet availability has stood at over 90%. This performance is only possible if safety is ensured throughout power plant operation.

Extending power plant life span

An efficient fleet is a fleet that ages well. A high-quality maintenance process is crucial to keeping power plants in perfect condition and extending their life span, initially estimated at a minimum of 40 years.
EDF entrusts part of the maintenance work to outside service providers that are accredited on the basis of their technical capability, quality assurance system and financial soundness. This approval is regularly re-assessed. EDF trains providers working at the sites in the operations to be carried out.
Crucial components such as the reactor vessel and containment are subject to special inspections, notably to monitor changes in the concrete they are built in. Modernisation works are scheduled to improve their performance. They are part of a broad programme that includes equipping reactors with a “hardened core” to store essential tools such as pumps and generators and adding further cooling sources.
Power plants are also subject to mandatory 10-year inspections carried out by EDF and overseen by the Nuclear Safety Authority (ASN), in which every component is painstakingly examined. These “check-ups” are scheduled so as to avoid affecting the average availability of the fleet. Following the inspection, ASN takes a decision to allow – or refuse – operation for another 10 years. To date ASN has not taken a negative decision regarding any power plant.