The North Anna nuclear power plant in Louisa, Va., has restored its normal power supply after a 5.8-magnitude earthquake forced it to operate on back-up generators briefly Tuesday, but the plant remains offline as inspections continue.

Jim Norvelle, spokesman for plant operator Dominion Virginia Power, said Wednesday that the plant “will be shut down until it is safe to restart,” though he could not say when exactly that would be. Both reactors at the North Anna plant will be going into a cold shutdown this week, which changes the atmospheric conditions of the coolant system to make it safe for inspectors to walk through the containment structure and check for any quake damage.

The 36-year-old facility,