A final, independent safety review has recommended that the Nuclear Regulatory Commission approve 20-year operating license extensions for FirstEnergy Corp.'s two nuclear reactors in Shippingport, Beaver County.

The report by the Advisory Committee on Reactor Safeguards includes a detailed discussion of containment liner corrosion problems and future testing mandates for the Beaver Valley Unit 1 and Unit 2 reactors but clears the way for the NRC's final decision on the license renewals as soon as next month.

The original 40-year operating license for Unit 1 expires in January 2016, and the license for Unit 2 runs until May 2027. The reactors, which together produce more than 1,900 megawatts of power, are located along the south bank of the Ohio River approximately 25 miles northwest of Pittsburgh.

The seven-page Advisory Committee report details the discovery in April of a small rust hole in Unit 1's 3/8-inch thick steel containment liner, located along the inside of the three-foot thick, steel-reinforced, concrete containment structure in which the nuclear reactor is located.

The report noted that corrosion of the liner had also been discovered along a weld in 2006, but concluded that both reactors could be operated for the extended period "without undue risk to the health and safety of the public."

The committee's site inspection also observed water in reactor manholes that contain medium-voltage cables, and recommended that FirstEnergy either demonstrate their safe usage or replace them with cables qualified for submerged use.

The advisory committee recommended that the NRC require FirstEnergy to follow a detailed supplemental inspection schedule for the containment liners of both reactors during refueling outages this fall and in 2010. All liner examinations and any necessary repairs must be made before the original licenses end.

"This step is an important milestone in the process," said Todd Schneider, a spokesman for the Akron, Ohio-based energy company. "We had a detailed discussion with the committee about the liners and will do additional inspections to make sure there is no corrosion.

"Safety is our top priority and we wanted to assure the ACRS that we can continue to operate safely and reliably."

Since 2000, the NRC has granted operating license extensions to more than half of the nation's 104 reactors, many of those done long before their original licenses were to end. No application to relicense a reactor has been denied.