Cornerstone	Performance Indicator			Thresholds
Mitigating Systems	The unavailability of safety system in the previous 12 quarters	All Plants	≦2EDG	≦2.5％	＞2.5％	＞5.0％	＞10.0％
			＞2EDG	≦2.5％	＞2.5％	＞10.0％	＞20.0％
		BWR	HPCS	≦1.5％	＞1.5％	＞4.0％	＞20.0％
			RHR	≦1.5％	＞1.5％	＞5.0％	＞10.0％
	The number of safety system functional failures in the previous 4 quarters		BWR	≦6.0	＞6.0	NA	NA
Barrier Integrity	The percentage of Reactor Coolant System specific activity to the Technical Specification limit in the previous 4 quarters			≦50.0％	＞50.0％	＞100.0％	NA
	Public Radiation Safety :The percentage of Reactor Coolant System leakage rate to the Technical Specification limit in the previous 4 quarters			≦50.0％	＞50.0％	＞100.0％	NA
Emergency Preparedness	Drill/Exercise Performance			≧90％	≧70％	＜70％	NA
	Emergency Response Organization Drill Participation			≧80％	≧60％	＜60％	NA
	Alert and Notification System Reliability			≧94％	≧90％	＜90％	NA
Occupational Radiation Safety	Occupational Radiation Exposure Control Effectiveness in the previous 4 quarters			≦2	＞2	＞5	NA
Public Radiation Safety	The performance of the Radiological Effluent Control Program in the previous 4 quarters			≦1	＞1	＞3	NA

：indicates performance within an expected performance level where the associated cornerstone objectives are met.
：represents performance outside an expected range of nominal utility performance but related cornerstone objectives are still being met.
：indicates related cornerstone objectives are being met, but with a minimal reduction in the safety margin.
：signals a significant reduction in safety margin in the area measured by the performance indicator.