A nuclear power plant in Massachusetts lost power and automatically shut down late on Friday during a massive blizzard across the northeastern United States, the nuclear regulator said.

The reactor at the Pilgrim Nuclear Power Plant in Plymouth closed down with no problems and there was no threat to public safety, an official at the Nuclear Regulatory Commission said.

"There was no impact on plant workers or the public," he said.

The snowstorm, which continued on Saturday, disrupted thousands of flights and left more than 200 000 people without power in Massachusetts alone.

It shut down roads and mass transit and blanketed the region with heavy snowfall.