Exelon Generation wants to ratchet up the electricity it produces at the Peach Bottom nuclear plant by 12.4 percent.

The U.S. Nuclear Regulatory Commission has accepted the application after initially sending it back for more information.

A thorough safety analysis would be required, as well as plant modifications, because increased steam generation would put additional stresses on plant systems, NRC spokesman Neil Sheehan said.

"The additional stresses placed on plant systems and components by an uprate require a detailed evaluation before it can be implemented," Sheehan noted.

Many of the necessary upgrades already have been made at the York County plant, according to Exelon Generation spokesman David Tillman. Other modifications and improvements are planned over the next three years.

"In support of extended power uprate, we have already performed low-pressure turbine replacements, replaced all six of Peach Bottom's main power transformers and refurbished the station's riverside cooling towers," Tillman said.

A thermal uprate involves increasing the output of steam from the nuclear reactor after uranium fuel is used to heat water.

The steam is piped to the turbine, which spins and generates electricity.

It is not unusual for nuclear plants to seek power uprates, Sheehan said. There have been more than 100 approved by the NRC dating to the 1970s.

"Plant owners seek them to allow more power output from an existing facility, where the infrastructure is already in place and it is therefore more cost-effective."

The NRC's standard review time for such an application is about 18 months.

Peach Bottom's two operating units opened in 1974. Unit 2's license to operate expires in 2033, Unit 3's in 2034.

acrable@lnpnews.com