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The major refit: a project for the future

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EDF estimates the cost of the major refurbishment project at 55 billion euros between 2008 and 2025. It is a costly project, but it will keep the price of electricity competitive because it will be less expensive than replacing aging power plants. In addition, this major refurbishment project will allow the implementation of continuous improvement actions by taking advantage of the feedback from the Chernobyl and Fukushima incidents.


The term "Grand Carénage" comes from the navy. Indeed, when the ship was put in dry dock for maintenance and repairs, it was called a careening.

Definition: a refit is a series of operations to periodically overhaul a ship's hull. The term comes from the hull: part of the hull underwater. The term also refers to the place in a port where this operation is performed: careening basin, dry dock, etc.

This concept was adopted by EDF in 2008. The project aims to extend the life of a nuclear power plant beyond 40 years.

The Great Renovation in nuclear power plants

The "Grand Carénage" is a multi-year project, aiming to extend the operating life of a nuclear power plant by 10 more years. The aim of the refit is mainly to replace old technologies with more recent ones, in particular with digitalization. Beyond maintenance operations, the objective is to replace and improve certain functions. The annual shutdowns are really planned to carry out minor maintenance, unlike the major refit.

This program includes a set of projects grouped according to three categories of activities:

  • Renovate or replace large components reaching the end of their technical life
  • Carry out the modifications necessary to improve safety
  • Ensuring the durability of equipment qualification after 40 years

The EDF Golfech power plant

Commissioned between 1990 and 1993, the EDF Golfech power plant is located in the Tarn et Garonne region. It has a key role in Occitania, since it supplies almost half (40%) of the region with electricity.

Since 2014, the EDF Group has launched the Grand Carénage of the Golfech power plant: an investment program aimed at allowing the continued operation, in complete safety, of French nuclear reactors, beyond the 40 years of planned activity. The Golfech plant was designed to operate for 40 years. The goal now is to keep it running for as many years as possible, ideally 60. At Golfech, the Grand Carénage will take place between 2020 and 2025.

Key figures:

  • 40% of the electricity needs of Occitania
  • 1000 employees of EDF or partner companies
  • 12g of CO₂/KWh emitted over the entire life cycle of the plant

The major refurbishment of the Golfech power plant represents a unique industrial challenge. It aims to further enhance the safety of the two electricity generation units. EDF teams and partners will be mobilized in large numbers to replace major components and modify the facilities to make them even safer.

For the Golfech plant, this major refurbishment will represent an investment of one billion euros. A real industrial challenge to ensure the long-term operation of the Golfech plant, the major refurbishment represents a major opportunity for the development of the region.

> Did you know? The Golfech nuclear power plant has the largest cooling towers in France!

The operation of a power plant

The operation of a nuclear power plant

In order to better understand the different elements that make up a nuclear power plant and how it works, you will find an explanatory diagram opposite.

A nuclear power plant is composed of three circuits: the primary circuit, the secondary circuit, and the cooling circuit.

Annual closures


In most companies, the annual shutdown is equivalent to a maintenance period. It lasts from one to four weeks and allows to perform operations that are impossible in normal times. These operations are diverse and more or less heavy depending on the company. They can be: cleaning and maintenance of floors, maintenance of equipment, replacement of machines or defective spare parts, etc. Production lines are overhauled and mechanical problems are solved. Some companies also take advantage of this opportunity to bring equipment up to standard or to modernize it.

In some sectors of activity such as heavy industry (metallurgy, foundry, nuclear, etc.), maintenance teams are particularly active during the annual shutdown. Some companies even call on external service providers to carry out all the necessary work.

Develop preventive maintenance

The shutdowns should also be used to implement preventive maintenance plans that are followed throughout the year. This will reduce unscheduled downtime, which is particularly harmful to the company's operations. For some companies, preventive maintenance interventions will even make it possible to avoid annual shutdowns in the future.

Preventive maintenance, carried out before the failure, will make it possible to check that the machines do not present any risk. Generally, it is the components and spare parts that are analyzed. Preventive maintenance is based on regulations, manufacturer's recommendations, but also on experience feedback.

Two types of preventive maintenance are possible:

  • Systematic preventive maintenance: it is based on periodicity. For example, technicians change the parts of a machine every month to improve its operation and avoid wear and tear on parts.
  • Conditional preventive maintenance: certain operating indicators are monitored, and the intervention is made only if the actual condition of the equipment requires it. It is possible to digitalize this system with computer tools.

Maintenance at BE ATEX

At BE ATEX, technicians can intervene to ensure maintenance operations on your equipment. Our technicians are experienced and authorized to intervene in your geographical area, and accompany you in the management and planning of preventive interventions.

As an Authorized Maintenance Center, our technicians are authorized by the manufacturers themselves, to intervene on the various products, whether they are gas detection (portable or fixed), respiratory protection or fall protection. Maintenance checks can be carried out directly on site, or in our workshop.

Our recommendations

In nuclear power plants, certain products are recommended:

For portable gas detection : BW Clip in single gas / X-AM 2500 in multigas (2 to 4) and X-AM 5100 for the hydrazine risk

For fixed gas detection : BM25

For detection by colorimetry : SPM Flex and Tubes colorimétriques

For respiratory protection : PAS X-PLORE and X-PLORE

For air quality control : VAR18

Titre du push

BE ATEX and nuclear power plants