Doel units 1 and 2

Unit 1 of the Doel nuclear power plant has been taken offline for the final time after 50 years of operation and disconnected from the grid. Its closure is in line with Belgium's 2003 nuclear phase-out policy, under which two other reactors have already been shut down.

Operator Electrabel, the Belgian subsidiary of France's Engie, said the 445 MWe (net) pressurised water reactor was shut down at 21:37 on 14 February.

"In the coming days, the operators will cool down the reactor in a controlled manner and lower the pressure in the primary cooling circuits to the level of the ambient air pressure," it said. "As soon as the plant has cooled down sufficiently, the unloading of the nuclear reactor can begin. In this process, the fuel rods are lifted out of the reactor one by one and transferred to separate docks, where they will continue to cool under water for several years."

A nuclear inspector from Belgium's Federal Agency for Nuclear Control (FANC) was present to supervise the shutdown process. "Technically, there is no difference with a normal shutdown for maintenance, except that the reactor will no longer be used to produce electricity after the final shutdown," FANC noted.

The country's federal law of 31 January 2003 requires the phase-out of all nuclear electricity generation in the country. Under that policy, Doel 1 was originally set to be taken out of service on its 40th anniversary – 15 February 2015. However, the law was amended in 2013 and 2015 to provide for Doel 1 to remain operational for an additional ten years. Duel 3 was closed in October 2022 and Tihange 2 in February 2023. Unit 1 of the Tihange plant is set to shut in October this year, with Doel 2 following in December. Belgium's last two reactors - Doel 4 and Tihange 3 - are currently scheduled to close in November 2025.

FANC noted that Doel 1 and 2 are so-called 'twin reactors', which means that they share certain components. For example, they have many common safety systems and a shared control room and machine room. "The first shutdown activities for Doel 1 will start in the coming weeks," it said. "Because Doel 2 will continue to operate until 30 November 2025, some of the shutdown activities will only take place when both reactors are no longer in use."

FANC added: "The process of the definitive shutdown of a nuclear reactor begins with the 'shutdown notification', a document that the reactor operator submits to the FANC for approval and that describes in great detail the activities that will be carried out after the shutdown in order to prepare the installation for its final dismantling. For example, the spent fuel is removed from the reactor vessel and cooled in the spent fuel pools, which quickly and significantly reduces the radiological risk to the environment. In addition, the operational waste is removed and pipes that are no longer needed are thoroughly flushed and emptied. All these preparatory activities take about five years.

"In the meantime, the operator also submits the applications for the necessary dismantling permits, both at federal (FANC competence) and regional level (regional competence). Only when all the permits have been granted can the actual dismantling works begin. These in turn will take another fifteen years or so."

Earlier this month, Belgium's new coalition government announced plans to continue operating the Doel 4 and Tihange 3 reactors for an additional 10 years beyond the 10-year extension already agreed - and said it aims to construct new reactors.