United States Nuclear Regulatory Commission - Protecting People and the Environment

Frequently Asked Questions About Post-Fire Operator Manual Actions

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What is a post-fire operator manual action (OMA)?

A post-fire OMA is a proceduralized activity carried out by plant personnel outside of the control room to respond to a fire and bring the plant to a safe and stable condition.

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What is the NRC's goal regarding the use of post-fire OMAs at nuclear power plants (NPPs)?

The main goal of the U.S. Nuclear Regulatory Commission (NRC) is safety. The NRC achieves this goal partly through the use of the defense-in-depth concept. As indicated in Appendix R to Title 10, Part 50, of the Code of Federal Regulations (10 CFR Part 50), the fire protection program extends the concept of defense-in-depth to fire protection with the following objectives: (1) prevent fires from starting; (2) detect rapidly, control, and extinguish those fires that do occur; and (3) provide protection for structures, systems, and components important to safety so that a fire that is not promptly extinguished by the fire suppression activities will not prevent the safe shutdown of the plant. The application of feasible and reliable post-fire OMAs is an important tool in achieving the third objective above.

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Why does the NRC allow post-fire OMAs in lieu of physical protection?

Significant plant fires are unusual events. Often, adequate safety may be ensured through the use of OMAs that have been analyzed and demonstrated to be effective in ensuring safe-shutdown capability. In such cases, the NRC’s paramount goal of safety is achieved without unnecessary regulatory burden being imposed on the licensees. However, where physical protection is needed to ensure adequate safety, the NRC will require physical protection.

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When will all plants be compliant?

According to the Enforcement Guidance Memorandum 07-004, “Enforcement Guidance Memorandum for Post-Fire Manual Actions Used as Compensatory Measures for Fire-Induced Circuit Failures,” licensees should have completed their modifications or submitted exemptions or license amendments to NRC for approval by March 6, 2009. On March 6, 2009, unapproved operator manual actions were considered non-compliances, unless the NRC was, at the time, reviewing an exemption or license amendment for that licensee.  The plants that submitted exemptions and amendments have had them dispositioned by the NRC staff, and no plants have enforcement discretion under EGM 07-004.

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Page Last Reviewed/Updated Tuesday, April 30, 2013