NRC uses its Reactor Oversight Process (ROP) to measure plant performance within the three broad areas of (1) reactor safety, (2) radiation safety, and (3) security. Within these areas, NRC looks at seven cornerstones: (1) Initiating Events, (2) Mitigating Systems, (3) Barrier Integrity, (4) Emergency Preparedness, (5) Occupational Radiation Safety, (6) Public Radiation Safety, and (7) Physical Protection.

If, from an assessment of inspection findings and performance indicators for a nuclear plant, NRC identifies repetitive degradation in a single cornerstone, NRC documents this plant degradation on an ROP matrix (see Inspection Manual Chapter 0305 , “Operating Reactor Assessment Program”) in the Multiple/Repetitive Degraded Cornerstone column. As a result of several failures associated in the cornerstone for Mitigating Systems at Point Beach Nuclear Power Station Units 1 and 2, NRC gave this plant such a rating and, therefore, will conduct a diagnostic inspection, following Inspection Procedure 95003 .