Local nuclear plants undergoing internal probes in wake of Japan disaster

As part of a worldwide reexamination of nuclear power in the aftermath of Japan's tsunami, America's largest nuclear-power producer anticipates that U.S. regulators will conduct a thorough - and costly - review of safety systems at the nation's 104 reactors.

Leaders of Exelon Corp. - which operates 17 U.S. nuclear-power plants, including the reactors closest to Philadelphia - said Thursday that the company has already launched internal investigations of its plants in response to Japan's unfolding nuclear catastrophe.

But John W. Rowe, Exelon's chairman and chief executive, told investment analysts that the company is confident of the safety of the reactors it operates at 11 sites in Pennsylvania, New Jersey, and Illinois.

"Our plants are not subject to the same earthquake and tsunami risks that have been experienced in Japan," Rowe said. "And despite the fact that they differ in some other material respects, we have begun focused safety reviews since the event, and our reviews to date continue to assure us that our plants are safe."

Exelon's reactors include Limerick Generating Station in Montgomery County; Peach Bottom Atomic Power Station in York County, Pa.; Oyster Creek Generating Station in Forked River, N.J., and Three Mile Island Unit 1 outside Middletown, Pa.

The Oyster Creek plant and the two Peach Bottom units have a design similar to the Japanese reactors'.

Rowe's expression of confidence in nuclear power - he called Exelon's fleet "the biggest asset in the American energy industry" - comes as support appears to be wavering for rejuvenation of a business that stagnated after the 1979 accident at Three Mile Island's Unit 2.

The Union of Concerned Scientists, a nonprofit American nuclear watchdog, has stepped up its calls for the Nuclear Regulatory Commission to more strictly monitor U.S. reactors.

"U.S. plants have the same key vulnerability that led to the crisis in Japan," the organization said in a statement.

An audit by the NRC's inspector general, released Thursday, also raised questions about the agency's oversight, saying reporting guidelines for the nuclear industry are "contradictory and unclear."

Antinuclear movements in Italy and Germany have picked up momentum since the disaster at the Fukushima Dai-ichi reactors, where critical cooling systems were disabled by the tsunami, leaving the reactors defenseless.