A woman reacts after being evacuated from her building as she waits to return after an earthquake struck the east coast of the United States, in New York, August 23, 2011. — Photo by Reuters

WASHINGTON: The earthquake that shook the US East Coast last week rattled huge, heavy casks holding radioactive nuclear waste at a Virginia plant, moving them as much as 4.5 inches from their original position, the plant's operator has said.

The 5.8-magnitude quake shifted 25 casks, each 16 feet tall and weighing 115 tonnes, on a concrete pad at Dominion Resources Inc's North Anna nuclear plant in Virginia, the Richmond Times-Gazette reported on Wednesday, citing company officials. “They just moved because of the vibration,” Dominion spokesman Rick Zuercher said. “They remained upright and fully intact.”

Officials from the company and the US Nuclear Regulatory Commission were not immediately available for comment.

The North Anna plant, located about 12 miles from the quake's epicentre near Mineral, Va., has been shut down since the August 23 quake as inspectors check for damage. The Nuclear Regulatory Commission is doing a special review because of preliminary data showing that shaking from the quake exceeded the plant's design rating.

The regulator already was scrutinising how well the US fleet of 104 reactors could withstand earthquakes, floods and other disasters after a quake and tsunami wrecked Japan's Fukushima Daiichi plant in March, the world's worst nuclear disaster in 25 years.

The United States, which has the world's largest nuclear power industry, has grappled for decades over how to permanently store waste, and the US government is considering a proposal for a network of centralised “dry cask” storage sites where plants could take their used fuel.