The US Nuclear Regulatory Commission (NRC) has placed 96 of the USA's 99 operating nuclear power reactors in the top two of its categories for performance in 2015. NRC assesses a licensee's safety performance based on information collected from inspections and performance indicators. From this, it determines the appropriate level of agency response, placing reactors into one of five performance categories.
Of the 96 highest-performing reactors, 85 fully met all safety and security performance objectives and were inspected under the commission's normal or "baseline" inspection programme. Eleven reactors needed to resolve "one or two" items of "low safety significance" and received extra regulatory inspections and the follow-up of their corrective actions. Three of those plants - Duane Arnold, Millstone unit 3 and Susquehanna units 1 and 2 - have now resolved their issues and been moved into the highest performance category, NRC noted.
There were no units in the third category of "degraded" performance, but three units - Arkansas Nuclear One units 1 and 2 and the single-unit Pilgrim plant - appear in the fourth performance category of "multiple/repetitive degraded" performance requiring increased regulatory oversight. These units receive additional inspections and NRC attention to confirm that performance issues are being addressed. There were no units in the NRC's fifth category of "unacceptable" performance.