US nuclear industry learns from Fukushima disaster

The March 11, 2011, tsunami knocked out power at the Fukushima Dai-ichi plant, cutting electricity to the plant's vital cooling system. Three reactors at the plant were damaged, releasing radiation into the atmosphere.

"The significance of a nuclear event is the lesson we can learn from it," said Jim Scarola, senior vice president and chief nuclear officer for Progress Energy and co-chairman of a national industry group.

The Nuclear Regulatory Commission on Friday ordered sweeping safety changes for the 104 nuclear power plants in the U.S., including requiring redundant back-up systems to prevent a similar incident.

"We can add another layer of defense, and there's benefit to adding that additional layer of defense," Scarola said. "I will never say that we're safe enough. I will always say that there's opportunity to be safer."

Nuclear plants provide 20 percent of the electricity used nationally and 49 percent in North and South Carolina, according to Progress Energy. Elizabeth Outz, director of Environment North Carolina, said the reliance on that source of power often overshadows the risks.

"I think what Fukushima proved is that even the best designs that engineers could come up with were not enough to counter the force of Mother Nature," Outz said.

Under the new NRC rules, nuclear plants also will have to install or improve venting systems to limit core damage in a serious accident, install sophisticated equipment to monitor water levels in pools holding radioactive spent fuel-rods and improve protection of safety equipment installed after the 2001 terrorist attacks.

Although U.S. plants must comply with the orders by the end of 2016, Scarola said Raleigh-based Progress Energy should have extra back-up generators and water pumps in all its nuclear plants, including Shearon Harris in southwest Wake County, by this summer to better prepare for natural disasters.

"No matter what that event is, the thing that's important to keep public safety becomes water and power," he said. "Our temporary equipment that is being put in every plant in the U.S. is all focused in on providing that water and power independent of what that initiating event was."