Five of EDF’s 15 nuclear reactors in the UK are out of service.
One went offline in October, four this month with three unplanned closures.
Torness Unit 2, Heysham 1 and Hartlepool are designed to safely shutdown in response to any issue affecting key systems, the company explained.
Earlier this week, Edinburgh-based demand response provider Flexitricity was called to secure power supply as a consequence of the Torness 2 reactor shutdown.
The reactors will return to service in the next coming days, EDF stated.
Hunterston B and Hartlepool unit 1 are closed for planned maintenance outages.
The company doesn’t know when they will be re-activated.