By Scott DiSavino Oct 26 (Reuters) - U.S. electric companies from Maine to Florida were bracing for heavy wind, rain and flooding that could take down power lines and threaten to close some East Coast nuclear plants early next week when Hurricane Sandy comes ashore. More than a dozen nuclear plants are located near Hurricane Sandy's path in North Carolina, Virginia, Maryland, New Jersey, Pennsylvania, New York and Connecticut, providing power to millions of customers in the region. See factbox Hurricane Sandy is currently passing over the Bahamas as a Category 1 hurricane with winds of about 80 miles per hour (128 kph) but has the potential to cause severe flooding from Virginia to Maine. Sandy is expected to remain a Category 1 hurricane as it marches north past the Outer Banks in North Carolina early Monday before hitting the Delmarva Peninsula early Tuesday, according to the latest forecast from the U.S. National Hurricane Center (NHC). Other weather forecasters said Sandy could hit anywhere from North Carolina to Nova Scotia in Canada, potentially knocking out power for millions in some of the biggest metropolitan areas in the United States, including New York, Philadelphia, Washington, Baltimore, Boston and Virginia Beach. Power companies from Maine to Florida have already started urging customers to prepare for possible power outages, as they mobilize crews and equipment to fix any damage that may occur. The last big storm to hit the U.S. East Coast was Hurricane Irene in 2011, which made landfall in the Outer Banks in North Carolina as a Category 1 storm. Irene caused billions in property damage as it ran up the coast from Carolinas to Maine. Irene left more than 7 million homes and businesses without power - some for a week or more in the hardest hit areas - and forced numerous power plants to shut, including at least two nuclear reactors, at Oyster Creek in New Jersey and Calvert Cliffs in Maryland. Other reactors reduced output ahead of the storm as a precaution and two of the three reactors at the Public Service Enterprise Group Inc (PSEG) Salem and Hope Creek plants in New Jersey cut output after the storm as debris in the Delaware River clogged the plant's intake system. A spokesman at the U.S. Nuclear Regulatory Commission (NRC) said the agency was monitoring Sandy's track very closely. "We're keeping a close eye on the coastal plants. All plants have procedures to deal with hurricanes, which include procedures to shut the reactors if winds are expected to reach a certain speed," NRC spokesman Neil Sheehan told Reuters. For example, PSEG must shut reactors at the Salem/Hope Creek plant two hours before hurricane force winds of over 74 miles per hour are expected to reach the site, Sheehan said. COASTAL REACTORS The coastal reactors include Dominion Resources Inc's Surry in Virginia, Constellation Nuclear Energy Group's Calvert Cliffs in Maryland, PSEG's Salem and Hope Creek in New Jersey, Exelon Corp's Oyster Creek in New Jersey and Dominion's Millstone in Connecticut. Constellation Nuclear is owned by units of Exelon and French power company EDF Group. A few of those reactors however were already shut for refueling outages, including Millstone 2 in Connecticut and Oyster Creek and Salem 2 in New Jersey. In addition to plans to deal with high winds, Sheehan said all of the reactors also have plans to deal with flooding. After the earthquake and tsunami damaged the Fukushima nuclear plant in Japan last year, the NRC made sure the reactors would be able to shut safely if floodwaters reached certain heights. The biggest utilities in the path of the storm include units of Duke Energy Corp, Exelon, FirstEnergy Corp, National Grid Plc, Consolidated Edison Inc, Northeast Utilities, Dominion, PSEG, PPL Corp, Pepco Holdings Inc and Iberdrola SA.