The project to extend the operation of the Doel 4 and Tihange 3 nuclear power plants: nuclear expertise, strict safety procedures and thorough inspections

Extending the operation of the Doel and Tihange nuclear power plants is a major project. Electrabel is deploying all its nuclear expertise and professionalism to ensure a responsible restart and safe long-term operation.

Doel 4 Tihange 3 The path towards operating Doel 4 and Tihange 3 for ten more years consists of three major phases:

  1. Conducting thorough safety analyses
  2. Inspecting and replacing components 
  3. Carrying out improvement works

As agreed with the Belgian government, Electrabelwill do everythingin its power to restart the Doel 4 and Tihange 3 plants in November 2025. 

Electrabel and its partners, including our engineering firm Tractebel, have the necessary expertise and experience to carry out this project safely and effectively. We have demonstrated this in the past with the projects aimed at extending the operation of Tihange 1 and Doel 1 and 2. In addition,the Federal Agencyfor Nuclear Control(FANC) is watchingover the safeexecution of thisproject, in linewith the regulatorynuclear safety framework.

Thorough safety analyses

By law, all nuclear power plants must be thoroughly reviewed every 10 years via a Periodic Safety Review (PSR). Subsequently, the safety authorities (FANC) must thoroughly check the results of these safety reviews, which may result in potential improvement actions that must be carried out within a period of three years. It is only once this report has been approved that the operator may continue to operate the plant for a further 10-year period. 

The Doel 4 and Tihange 3 nuclear power plants started operating in 1985. At the time of construction, it was assumed that they would remain in operation for at least 40 years (i.e. until 2025). Therefore, operating both nuclear power plants for an additional ten-year period (we call this Long Term Operation or LTO), requires a Periodic Safety Review (PSR-LTO). The PSR-LTO comprises a systematic assessment of the nuclear safety of the plants with a view to extending their operation. It is primarily a thorough review of the condition of the plants' systems, structures, and components. In practice, this means that we will preventively replace a number of components or install new systems in order to meet the highest safety standards.

The operator must submit a summary report of this review to the safety authority. This summary report includes, for all safety topics, an identification of differences between the condition of the plant and current nuclear safety rules & practices, together with an assessment and possible justification of the acceptability of the differences. The report also includes a list of corrective actions and safety improvements to be implemented and a detailed schedule for their implementation.

Inspecting and replacing components 

As soon as Doel 4 and Tihange 3 are stopped, our teams will get to work. In the space of a few weeks, the power plants will undergo a first round of thorough maintenance. We will check the components and replace them where necessary. We will test all systems thoroughly and will also load new fuel.

For Tihange 3, this will happen during the already planned outage starting in early April 2025 until early July. Doel 4 will remain operational until its 40th anniversary on 1 July. By 1 November, this unit will also return to operation.We prepare this overhaul meticulously months in advance. Where possible, we take samples and test parts ahead of time. Given the time constraints, we will order certain parts long in advance. These are often very specific parts that have to meet extremely high requirements. For overhaul work, we also call on the services of specialised companies and they too are already drawing up their schedules.

The overhaul is followed by an inspection by the FANC. Only after they have given the green light can the power plants be restarted.

Carrying out improvement works

Further improvement works will follow in the summers of 2026, 2027, and 2028. In this way, we can guarantee maximum availability during the winter months. If all goes well, we will complete all works by the end of 2028. This is in line with the expectations of the Federal Agency for Nuclear Control.

Doel 4 and Tihange 3 are Pressurized Water Reactors, one of the most robust and safest type of nuclear power plant. Based on global experience and new technologies, these nuclear power plants undergo continuous improvements to avoid incidents and further reduce the impact of incidents. 

These design upgrades are internationally defined. In consultation with FANC, Electrabel examines which adjustments need to be made, taking into account the specific situation. This assessment reviews the age of the systems, improvements already carried out, location of the power plant, etc.

For Doel 4 and Tihange 3, we will be carrying out a number of major works in the coming years. Based on initial analyses, these include:

  • Replacement of the turbine control system
  • Replacement of various motors and electrical boards 
  • Replacement of measuring systems 
  • Works to the cooling towers
  • Replacement of the primary pump seals with a new type of seal
  • and more...

Analyses are currently being conducted to determine the final scope of the improvement works to be carried out. 

A tight timeline

Some 300 employees of Electrabel, Tractebel, and other companies are working full-time to complete all reviews and prepare works. The FANC, the nuclear safety body in Belgium, is also closely involved.

In addition, the government has an important mission. Keeping the nuclear plants in service after 2025 required, among other things, several legislative changes. Setting up the new Joint Venture (50% ENGIE and 50% Belgian government) that will own the extended nuclear power plants will also require efforts from both partners. Finally, the European Union must also give its approval to the agreement that the Belgian government concluded with ENGIE. The necessary steps are being taken to ensure that this is done.

Our mission

For decades, we have operated the nuclear power plants in a safe and professional manner. In this way, we have contributed to ensuring our country’s stable energy supply. It is on the basis of that same nuclear professionalism that we will be taking on the challenge of restarting and further operating Doel 4 and Tihange 3. Safety, a sense of responsibility and care for people and the environment are the cornerstones of our commitment.