The nation’s oldest operating nuclear plant, however, does not pose a safety hazard for workers or the public as a result of this problem, reports Associated Press.

The problem had been discovered at the power plant, but it’s not yet clear what caused the leak which is being repaired by the workers.

US-based power generator Exelon mentioned on its website that the single boiling water reactor at its Oyster Creek station produces 645MW net, enough electricity to power 600,000 average homes in the country.

The power generating facility has been offline due to a refueling outage that started 22 October. NRC said the plant is safe. But it’s not known when it will resume power production.