The redundancy principle

The nuclear power plants of Doel and Tihange have extensive safety systems that are designed to compensate for possible defects. All safety-relevant equipment therefore exists in threefold redundancy. This is the essence of the principle of redundancy: a defect in one component can never compromise the safety of the power plant.

Containment barriers

Everything is done to prevent the release of radioactive substances to the outside world. A range of containment barriers completely encloses the uranium and the highly-active fission products.

Did you know? The nuclear fuel is enclosed by 5 barriers to prevent the release of radioactivity.

1. The uranium oxide is compressed into fissile fuel pellets
2. The tablets are inserted into fuel rods
3. The fuel rods are grouped into fuel assemblies which are placed in the reactor vessel. The reactor vessel is a 25 cm thick steel container.
4. A first primary containment wall prevents any possible release of radioactivity from the reactor building. The wall can withstand high pressure from the inside.
5. A second containment wall in reinforced concrete protects the reactor from external accidents. It is designed to withstand different types of impacts, such as explosions, flooding, earthquakes, aircraft crash… Between the two containment walls a slight vacuum is maintained to ensure that there can be no uncontrolled release of radioactivity to the outside world.

A strong safety culture

In order to be one of the best nuclear operators worldwide, we are also strongly committed to the human factor. Therefore, developing and strengthening a culture in which safety is a natural reflex are key elements in our five-yearly global nuclear safety plans.

The 2,000 employees of the Doel and Tihange nuclear power plants are highly qualified and have a great deal of experience. The operators in the control room must have a special licence, which is renewed every 2 years. In order to do so, they must first undergo intensive training on a simulator and pass an exam for an independent control body. Every year, internal and external emergency planning exercises are organised in collaboration with the plant staff.

Did you know? The nuclear power plants at Doel and Tihange have their own training centres with a simulator that faithfully simulates all aspects of the plant’s operation.