Nuclear Safety: NRC's Oversight of Fire Protection at U.S. Commercial Nuclear Reactor Units Could Be Strengthened
Highlights
After a 1975 fire at the Browns Ferry nuclear plant in Alabama threatened the unit's ability to shut down safely, the Nuclear Regulatory Commission (NRC) issued prescriptive fire safety rules for commercial nuclear units. However, nuclear units with different designs and different ages have had difficulty meeting these rules and have sought exemptions to them. In 2004, NRC began to encourage the nation's 104 nuclear units to transition to a less prescriptive, risk-informed approach that will analyze the fire risks of individual nuclear units. GAO was asked to examine (1) the number and causes of fire incidents at nuclear units since 1995, (2) compliance with NRC fire safety regulations, and (3) the transition to the new approach. GAO visited 10 of the 65 nuclear sites nationwide, reviewed NRC reports and related documentation about fire events at nuclear units, and interviewed NRC and industry officials to examine compliance with existing fire protection rules and the transition to the new approach.
Recommendations
Recommendations for Executive Action
Agency Affected | Recommendation | Status |
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Nuclear Regulatory Commission | To address long-standing issues that have affected NRC's regulation of fire safety at the nation's commercial nuclear power units, the NRC Commissioners should direct NRC staff to develop a central database for tracking the status of exemptions, compensatory measures, and manual actions in place nationwide and at individual commercial nuclear units. | NRC agreed with the recommendation and stated in its 60-day letter it would implement the recommendation by the end of FY2010. As with all the recommendations in this report, NRC initially did not make specific comments, but said the report was accurate and complete and stated it intended to give the findings and recommendations serious consideration. On 3/19/2010, NRC reported licensees track fire protection deficiencies, exemptions and deviations, including any involving compensatory measures and manual actions. NRC sampled those measures and manual actions during routine fire protection inspections. On that basis, NRC determined that existing compensatory measures and manual actions... ensure adequate fire protection at each nuclear plant. Moreover, NRC reports that in December 2009, it completed the development of a centralized database of fire protection exemptions for operating nuclear reactors.
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Nuclear Regulatory Commission | To address long-standing issues that have affected NRC's regulation of fire safety at the nation's commercial nuclear power units, the NRC Commissioners should direct NRC staff to address safety concerns related to extended use of interim compensatory measures by (1) defining how long an interim compensatory measure can be used and identifying the interim compensatory measures in place at nuclear units that exceed that threshold, (2) assessing the safety significance of such extended compensatory measures and defining how long a safety-significant interim compensatory measure can be used before NRC requires the unit operator to make the necessary repairs or replacements or request an exemption or deviation from its fire safety requirements, and, (3) developing a plan and deadlines for units to resolve those compensatory measures. | In essence, NRC disagreed with the recommendation and likely will not implement it. As with all the recommendations in this report, NRC initially did not make specific comments, but said the report was accurate and complete and stated it intended to give the findings and recommendations serious consideration. In its 60-day letter, however, NRC stated that while the implementation of long-term interim compensatory measures is less than ideal, that situation does not introduce safety concerns because (1) defense in depth at nuclear plants provides adequate protection, and (2) NRC inspectors periodically inspect a sample of each plants compensatory measures for adequacy. NRC states that as...
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Nuclear Regulatory Commission | To address long-standing issues that have affected NRC's regulation of fire safety at the nation's commercial nuclear power units, the NRC Commissioners should direct NRC staff to address long-standing concerns about the effectiveness of fire wraps at commercial nuclear units by analyzing the effectiveness of existing fire wraps and undertaking efforts to ensure that the fire endurance tests have been conducted to qualify fire wraps as NRC-approved 1- or 3-hour fire barriers. | Initially, as with all the recommendations in this report, NRC initially did not make specific comments, but said the report was accurate and complete and stated it intended to give the findings and conclusions serious consideration. In its 60-day letter, NRC stated it has been working on resolving fire-wrap issues since the early 1990s; specifically, it has reviewed design and test results from vendors, observed fire barrier configurations at selected plants, performed small scale testing itself, and as a result has updated NRC guidance on testing and acceptance criteria. NRC adds it has taken additional steps including periodic safety inspections, issuance of generic communications,...
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Nuclear Regulatory Commission | To address long-standing issues that have affected NRC's regulation of fire safety at the nation's commercial nuclear power units, the NRC Commissioners should direct NRC staff to address long-standing concerns by ensuring that nuclear units are able to safeguard against multiple spurious actuations by committing to a specific date for developing guidelines that units should meet to prevent multiple spurious actuations. | CLOSED-IMPLEMENTED: NRC agreed with the recommendation, and as with all the recommendations in this report, NRC initially did not make specific comments, but said the report was accurate and complete and stated it intended to give the findings and conclusions serious consideration. In its 60-day letter, NRC stated it had been working since the mid-1990s to address the complex issue of fire-induced circuit failures. On June 20, 2008, NRC staff presented the Commission via SECY-08-0093 with an approach for resolving those issues, and the Commission approved the document by Sept. 3, 2008. A review of NRC literature shows that NRC implemented a "CAROLFIRE" initiative to address these issues....
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