Washington - Hurricane Sandy's wrath shows that U.S. regulators should swiftly implement nuclear-safety rules developed after Japan's Fukushima disaster, a top lawmaker says, as industry officials said the lack of major problems during the storm showed that they were ready.

"U.S. regulators have an opportunity and a responsibility to prepare for natural disasters and extreme weather," Rep. Edward Markey of Massachusetts, the top Democrat on the House Natural Resources Committee, said in a statement.

"An immediate first step is to fully implement the safety upgrades recommended by the Fukushima task force in a manner that ensures they are mandatory, in recognition of the fact that they are necessary to ensure the adequate protection of America's nuclear power plants," he said.

Hurricane Sandy this week pummeled the northeast United States, forcing three reactors to shut down, and a fourth, Exelon Corp.'s Oyster Creek facility in New Jersey, to declare an alert.

The Nuclear Regulatory Commission, which had dispatched inspectors armed with satellite phones to plants in the storm's path, said that all safety systems in the three idled reactors responded as designed during the hurricane.

"Our facilities' ability to weather the strongest Atlantic tropical storm on record is due to rigorous precautions taken in advance of the storm," Marvin Fertel, chief executive officer of the Nuclear Energy Institute, a Washington-based industry group, said in a statement.

Of the 104 operating U.S. reactors, 34 were in the hurricane's path and 24 survived the storm without any incident, according to NEI. Seven units weren't operating because they were being refueled and inspected, which typically happens during months when electricity demand is relatively low.

The NRC in March approved its first rules inspired by last year's triple meltdown at Tokyo Electric Power Co.'s Fukushima Dai-ichi plant, triggered by an earthquake and tsunami. The plant lost off-site power and backup generators failed.

The new NRC rules, including one that requires reactors to have emergency equipment in place to indefinitely survive a blackout, are scheduled to be in place by 2016.

Reactor owners have begun buying mobile equipment, including pumps and generators to have in the event of an emergency. While Chicago-based Exelon has installed portable, diesel-fueled pumps at its facilities in response to the NRC's Fukushima regulations, the company didn't need to use them to respond to Hurricane Sandy, David Tillman, a spokesman for Exelon Nuclear, said in an email.

Public Service Enterprise Group of Newark purchased three pumps in response to the agency's regulations, and also didn't need to use them, PSEG Nuclear spokesman Joseph Delmar said in a phone interview.

Operators and federal regulators benefited from forecasts about the storm's path and intensity.

"The fact that they knew this storm was coming allowed them to take action," Dale Klein, a former chairman of the Nuclear Regulatory Commission and now associate vice chancellor at the University of Texas, said in an interview. "I think it was relatively easy. They prepare for hurricanes all the time."

Sandy, the biggest Atlantic Ocean tropical storm on record, moved along the East Coast for five days before slamming into the mid-Atlantic coast Oct. 29, unlike the Japanese event, which struck with much less warning.

Critics of U.S. nuclear-safety requirements said a few breaks, including that reactors such as Oyster Creek were idled for refueling, prevented a disaster, and that plants need stiffer government standards to cope with a likely increase in the number and severity of storms.

"We really need to re-evaluate plant safety in light of global warming and stronger storms," Arnold Gundersen, the chief engineer of Fairewinds Energy Education Corp., a Burlington, Vt.-based non-profit that studies nuclear safety issues for clients such as the environmental group Greenpeace, said in an interview.

It "changes the design basis of a plant."

The NRC dispatched extra inspectors to 10 nuclear plants in the storm's path across the mid-Atlantic and New England regions.

"Our plants responded very well," Steve Kerekes, a spokesman for the Nuclear Energy Institute, said Tuesday in an interview. "The majority of them are still producing electricity, which is obviously needed."

PSEG manually closed its 1,174-megawatt Salem Unit 1, about 18 miles south of Wilmington, Del., when four of six circulating pumps were no longer available because of weather, Delmar said.

Nine Mile Point's unit 1 in Scriba, New York, run by a joint venture of Exelon Corp. of Chicago and Electricite de France in Paris, automatically shut down after a power disruption to a switch yard, the NRC said. Entergy Corp.'s Indian Point 3 plant in New York also automatically closed because of power-grid issues, Neil Sheehan, an NRC spokesman said in an email.

"Nuclear plant operators throughout the region had their hands full dealing with this historic storm," Sheehan said. "While three reactors experienced shutdowns, all are in a safe condition."

The nation's oldest nuclear plant, Exelon's Oyster Creek, declared an alert Oct. 29 after a water-intake structure flooded, according to an NRC statement. The plant, about 33 miles north of Atlantic City, was idle for refueling.

Exelon said the alert was declared when water rose above 6 feet above sea level. A disruption was also reported at the plant's switch yard, which delivers power to the plant. Diesel generators kicked in automatically.

Sandy may be the impetus for operators to reassess disaster protection, Robert Alvarez, a scholar at the Institute for Policy Studies in Washington, said in an interview.

"There might be some interesting information about vulnerabilities being uncovered," said Alvarez, a senior policy adviser to the Energy secretary during the Clinton administration.