The Doel 2 nuclear reactor, which came to a halt on Thursday morning, is due to restart on Saturday, Engie Electrabel confirmed.
An automatic stop occurred at Doel 2 on Thursday around 9.45 am, due to a short circuit - described by a company spokesperson as a "purely operational problem" and "no threat to safety."
Initially, the plant had been expected to restart on Friday by 9.45 a.m., but it is now estimated that this will happen a day later, at about 7.00 a.m. on Saturday.
Further interventions and tests are taking place to determine when the reactor can effectively be restarted, spokeswoman Hellen Smeets said on Thursday evening.
On Monday, Tihange 3 also stopped unexpectedly. That left four of the six power stations running. A seventh plant, Doel 3, was permanently disconnected from the grid at the end of September and is therefore no longer available.
With the temporary stoppage at Doel 2 and Tihange 3, Belgium still has 3.5 of its 5.0 gigawatts of nuclear capacity available.
The suspension of generation at Doel 2 has apparently caused little disruption to the electricity market: a great deal of power is available from solar panels, dealers said.