The Nuclear Regulatory Commission (NRC) issued its annual assessment of the nation’s 100 operating commercial nuclear power plants on Mar. 6.

The results—for performance through 2013—showed that 80 plants were meeting all safety and security standards, while nine more were doing well enough to warrant only slight additional oversight due to one or two items of low safety significance. Then there were the other 11.

Nine fell into the third performance category, referred to as the degraded cornerstone column, although three of those—Sequoyah 1 and 2, and Watts Bar 1—have since resolved their issues and transitioned to the highest performance level. The six that still remain in the degraded cornerstone column include: Browns Ferry 2 (Ala.), Duane Arnold (Iowa), Monticello (Minn.), Pilgrim (Mass.), Point Beach 1 (Wisc.), and Susquehanna 2 (Pa.).

Browns Ferry 1 in Alabama was the only unit in the multiple/repetitive degraded cornerstone column, the fourth category. It was deemed to need increased oversight as the result of a safety finding of high significance.

The last unit on the list was Fort Calhoun in Nebraska. It was under a special NRC oversight program due to its extended shutdown and significant performance issues. It received NRC permission to restart in December 2013, but it will not be issued an assessment until the oversight panel returns it to the regular program.

Aaron Larson, associate editor (@AaronL_Power, @POWERmagazine)