Hydro-Quebec will undertake urgent repairs on the Gentilly-2 nuclear power plant due to a crack in the structure, but the authorities say the damage is superficial and not dangerous.
A one to two meter crack has been spotted in the ring around Gentilly-2's cement dome.
Hydro-Quebec says a piece could fall onto a neighbouring building, so repairs are being launched for the safety of the workers.
"I think these repairs had to be done but what I'm saying to you is that what I heard from hydro is that there is no threat to the population," says Natural Resource minister Pierre Arcand.
"It does not cause any threat to the structure itself."
Hydro-Quebec calls the measure a precaution.
The Parti Quebecois announced the plant's shut down two years ago, but it will take 50 years for a nuclear power plant to be fully decommissioned.