WASHINGTON–The Nuclear Regulatory Commission issued letters to the nation’s 99 commercial operating nuclear plants about their performance in 2015. All but three plants were in the two highest performance categories.

“These assessment letters are the result of a holistic review of operating performance at each domestic power reactor facility,” said Bill Dean, director of the Office of Nuclear Reactor Regulation. “In addition to ensuring that the nation’s nuclear power plants are safe by inspecting them, the NRC continuously assesses performance. The purpose of these assessment letters is to ensure that all of our stakeholders clearly understand the basis for our assessments of plant performance and the actions we are taking to address any identified performance deficiencies.”

Of the 96 highest-performing reactors, 85 fully met all safety and security performance objectives. These reactors were inspected by the NRC using the normal “baseline” inspection program.

Eleven reactors need to resolve one or two items of low safety significance. For this performance level, regulatory oversight includes additional inspections and follow-up of corrective actions. Plants in this level are: Clinton (Illinois); Davis Besse (Ohio); Dresden 2 (Illinois); Duane Arnold (Iowa); Indian Point 3 (New York); Millstone 3 (Connecticut); Prairie Island 2 (Minnesota); River Bend (Louisiana); Sequoyah 1 (Tennessee); and Susquehanna 1 and 2 (Pennsylvania).

Duane Arnold, Millstone 3, and Susquehanna 1 and 2 have resolved their issues since the reporting period ended and have transitioned to the highest performing level.

There were no reactors in the third performance category with a degraded level of performance.

There were three reactors in the fourth performance category. Arkansas Nuclear One 1 and 2 (Arkansas) require increased oversight because of two safety findings of substantial significance. Pilgrim (Massachusetts) is in the fourth performance category because of long-standing issues of low-to-moderate safety significance. Reactors in this category receive additional inspections and increased NRC management attention to confirm performance issues are being addressed.

Later this year, the NRC will host a public meeting or other event in the vicinity of each plant to discuss the details of the annual assessment results. A separate announcement will be issued for each meeting.

The NRC routinely updates information on each plant’s current performance and posts the latest information as it becomes available to the action matrix summary.

Every six months each plant receives either a mid-cycle or annual assessment letter along with an NRC inspection plan.