United States Nuclear Regulatory Commission - Protecting People and the Environment
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Performance Assessment Basics

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How does NRC assess the performance of a nuclear power plant?

The NRC uses inspection findings together with objective performance indicators (PI), which the licensees submit, to assess plant performance within a regulatory framework of seven cornerstones of safety: (1) initiating events, (2) mitigating systems, (3) integrity of barriers to release of radioactivity, (4) emergency preparedness, (5) occupational radiation safety, (6) public radiation safety, and (7) security. Both PIs and inspection findings are evaluated and given a color designation based on their safety significance. Green inspection findings or PIs indicate a very low risk significance and therefore have little or no impact on safety. White, yellow, or red inspection findings or PIs each, respectively, represent a greater degree of safety significance.

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What is a performance indicator?

A performance indicator is a quantitative measure of a particular attribute of licensee performance that indicates how well a plant is performing when measured against established thresholds. Licensees submit this data quarterly, and the NRC regularly performs verification inspections of their submittals. As previously mentioned, the NRC uses its analysis of this data with its own inspection data for assessment of a plant's performance.

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How does NRC act on its assessment of a plant - what are the results?

Each region maintains an awareness of licensee performance at each site under their cognizance. On a quarterly basis, the NRC reviews PIs and inspection findings and determines the appropriate level of engagement as dictated by the Action Matrix.

More formal reviews are conducted at the mid-point and end of the 12-month assessment cycle. Each plant receives an assessment letter with an attached inspection plan as a result of these meetings.

Additionally, the regions maintain a continuous awareness of licensee performance. As discussed in the IMC 0305 "Operating Reactor Assessment Program," additional agency actions may be taken between quarterly reviews as declining performance information becomes available.

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Are these assessments available to the public?

The performance indicators, inspection findings, and the assessment letters describing plant performance are posted to the NRC Web site. For more information on assessment results, see Reactor Oversight Process. Although the NRC is actively overseeing the Security Cornerstone, the Commission has decided that the related inspection and assessment information will not be publically available to ensure that potentially useful information is not provided to a possible adversary.

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Page Last Reviewed/Updated Friday, June 12, 2015