Federal regulators are calling for stepped-up safety inspections at the Browns Ferry Unit 1 nuclear plant in Alabama and the Fort Calhoun plant in Nebraska.

The Nuclear Regulatory Commission released a midyear performance review today that found the two plants must receive additional oversight during the next year until poor plant performance issues are addressed.

The agency found all 104 U.S. reactors are operating safely, with 92 plants performing at the highest safety level, but it said eight plants must resolve issues of low safety significance and will receive additional inspections. Three plants in South Carolina, Ohio and Pennsylvania were at the third level of performance and will undergo more inspections.

NRC said the Tennessee Valley Authority's Browns Ferry plant, about 100 miles south of Nashville, Tenn., and Omaha Public Power District's (OPPD) Fort Calhoun plant, about 19 miles north of Omaha, Neb., require the "highest level of attention" to ensure performance issues at the plants are being addressed.

OPPD said in a statement today that NRC's concern for the Fort Calhoun plant stems from findings unrelated to this summer's historic flooding on the Missouri River.

Instead, NRC earlier this year found the plant's control system failed during testing. The equipment has since been fixed, OPPD said. NRC inspectors also found some of the plant's flood protections and procedures were not written down. Now that flooding in the area has subsided, OPPD said it is working with NRC to address those concerns.

The Fort Calhoun plant is recovering from historic flooding on the Missouri River.

Last Friday, NRC approved steps OPPD must take before restarting the 478-megawatt plant, which has been shut down since April for refueling. The outage was extended after rising floodwaters surrounded the site. An electrical fire on June 7 caused further restart complications at the plant, but the plant has remained in a safe shutdown mode, according to NRC.

TVA spokesman Ray Golden said NRC's call for more inspections at the Browns Ferry plant came after the commission found an injection valve on the plant's cooling system failed to operate in May (Greenwire, May 10).

TVA said last October that the cooling system's valve -- which cools the reactor during accidents -- failed to open. The commission then issued TVA a violation and accused the operator of failing to realize the valve had been stuck since March 2009.

TVA has since appealed the safety violation, arguing that the valve is part of the residual heat removal system that plays no safety-related role. NRC has disagreed and said the malfunctioning valve could have led the reactor's core to overheat (Greenwire, Aug. 18).