Belgium’s Doel 4 restarted on 13 December after a four-month unplanned outage following the discovery of concrete degradation in a building that houses backup safety systems.

Belgian nuclear operator Electrabel, a subsidiary of French energy company Engie, said the unit returned to service two days ahead of schedule after Belgium’s nuclear regulator, the Federal Agency for Nuclear Control (Fanc), approved its restart.

Fanc said the degradation problem had been solved and the 1038MWe pressurised water reactor unit, which was shut down on 6 August could be operated safely.  Doel 4 began commercial operation in 1985.
Fanc and its technical subsidiary Bel V Fanc monitored the repair work   through site inspections and the review and evaluation of documents, quality plans and test results.  Engie Electrabel was asked to demonstrate the resistance of the building before any restart.  

Similar concrete degradation issues were identified at Tihange 2&3 which are expected to remain offline until March 2019 at the earliest. Doel 3, which was also affected, returned to service last year.

Six of the  Belgium’s seven nuclear units (four at Doel and three at Tihange) had been offline for maintenance in recent months. With the return to service of Doel 4, four units will remain offline: Tihange 2&3 due to concrete degradation issues and Doel 1&2 following the discovery of leak at Doel 1.

Photo: Doel nuclear plant