ML18153B075
| ML18153B075 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 09/19/1994 |
| From: | Zimmerman R Office of Nuclear Reactor Regulation |
| To: | Ohanlon J VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| GL-92-08, GL-92-8, TAC-M85611, TAC-M85612, NUDOCS 9409260100 | |
| Download: ML18153B075 (8) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555--0001 Mr. J. P. O'Hanlon Senior Vice President - Nuclear 5000 Dominion Blvd.
Glen Allen, Virginia 23060 September 19, 1994
SUBJECT:
FOLLOW-UP TO THE REQUEST FOR ADDITIONAL INFORMATION REGARDING GENERIC LETTER 92-08 ISSUED PURSUANT TO 10 CFR 50.54(F) ON DECEMBER 21, 1993-SURRY POWER STATION, UNITS NO. 1 AND NO. 2 (TAC NOS. M85611 AND M85612)
Dear Mr. O'Hanlon:
This letter acknowledges receipt of your letter dated January 27, 1994, which responded to the U.S. Nuclear Regulatory Commission (NRC) staff's request for additional information (RAI) regarding Generic Letter 92-08, 11 Thermo-Lag 330-1 Fire Barriers.
11 In addition, we are providing information regarding NRC's
.course of action to resolve the Thermo-Lag issue and guidance on exemptions.
In your letter of December 23, 1993, you stated replacement of Thermo-Lag with Pyrocrete has been completed for one application and, with one*exception, engineering evaluations have also been completed for the remaining applications at the Surry Power Station.
You are now required to submit the information specified in the 50.54(f) letter for those areas in which your response was incomplete.
In SECY-94-127 dated May 12, 1994, the staff informed the Commission of four options the staff was considering for resolving the Thermo-Lag fire barrier technical issues.
On May 20, 1994, the staff briefed the Commission on the options.
The-staff recommended continuation of NRC staff and industry efforts to return the plants with Thermo-Lag barriers to compliance with existing NRC fire protection requirements consistent with the staff's Thermo-Lag Action Plan.
The staff stated that if the Commission approved this option, the staff would consider plant-specific exemptions from certain technical requirements of Appendix R to 10 CFR Part 50 on a case-by-case basis, provided the licensee submits a technical basis that demonstrates that the in-plant condition provides an adequate level of fire safety.
In a Staff Requirements Memorandum (SRM) of June 27, 1994, 110ptions for Resolving the Thermo-Lag Fire Barrier Issues," the Commission (with all Commissioners agreeing) approved the NRC staff recommendation to return plants to compliance with existing NRC requirements and to permit plant-specific exemptions where technically justified.
In addition, in the SRM, the Commission approved the staff recommendation not to proceed with the development of a performance-based approach to resolve the Thermo-Lag issue.
On the basis of NRC staff review of your response to the RAI for the Thermo-Lag barriers that will remain in place, the information submitted for the following sections is incomplete:
Section Ill, 11Thermo-Lag Fire Barriers Outside the Scope of the NUMARC Program 11 and Section IV, 11 Ampaci ty De rating."
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Dunning1.on 9/ /(/)/94 PD:PDII-ADP f+ RZimmerman Mr. J. P. O'Hanlon Virginia Electric and Power Company cc: Michael W. Maupin, Esq. Hunton and Williams Riverfront Plaza, East Tower 951 E. Byrd Street Richmond, Virginia 23219 Mr. David Christian, Manager Surry Power Station Post Office Box 315 Surry, Virginia 23883 Senior Resident Inspector Surry Power Station U.S. Nuclear Regulatory Commission 5850 Hog Island Road Surry, Virginia 23883 Chairman Board of Supervisors of Surry County Surry County Courthouse Surry, Virginia 23683 Dr. W. T. Lough Virginia State Corporation Commission Division of Energy Regulation Post Office Box 1197 Richmond, Virginia 23209 Regional Administrator, Region II U.S. Nuclear Regulatory Commission 101 Marietta Street N.W., Suite 2900 Atlanta, Georgia 30323 Robert B. Strobe, M.D., M.P.H. State Health Commissioner Office of the Commissioner Virginia Department of Health P.O. Box 2448 Richmond, Virginia 23218 Surry Power Station Units 1 and 2 Attorney General Supreme Court Building 101 North 8th Street Richmond, Virginia 23219 Mr. M. L. Bowling, Manager Nuclear Licensing & Programs* Virginia Electric and Power Company Innsbrook Technical Center 5000 Dominion Blvd. Glen Allen, Virginia 23060 1.0 Introduction FIRE PROTECTION EXEMPTIONS, DEVIATIONS, AND LICENSE AMENDMENTS ENCLOSURE The U.S. Nuclear Regulatory Commission (NRC) adheres to the application of a defense-in-depth concept of echelons of safety systems to achieve the high degree of safety required for nuclear power plants. This concept is also applicable to nuclear power plant fire safety. The defense-in-depth approach applied to the fire protection program is designed to achieve an adequate balance in:.(1) preventing fires from starting; (2) detecting quickly, controlling, and extinguishing promptly those fires that occur; and (3) protecting structures, systems, and components so that a fire that is not promptly extinguished will not prevent the safe shutdown of the plant. NRC fire protection requirements and guidance implement this defense-in-depth approach and specify a level of fire protection which considers the potential consequences that a fire may have on the safe shutdown of the reactor. The *NRC fire protection regulation is Title 10 of the U.S. Code of Federal Regulations, Part 50, Section 50.48, "Fire protection," (10 CFR 50.48). Section 50.48 states that each operating reactor must have a fire protection program that satisfies General Design Criterion (GDC) 3, "Fire protection," of Appendix A, "General Design Criteria for Nuclear Power Plants," to 10 CFR Part 50. The objective of the fire protection program is to minimize both the probability and consequences of fire~. Appendix R, "Fire Protection Program for Nuclear Power Fa.cilities Operating Prior to January 1, 1979," to 10 CFR Part 50 establishes fire protection features required to satisfy GDC 3. The Appendix R requirements of interest here are specified in Section III.G, "Fire protection of safe shutdown capability." Guidance for implementing NRC fire protection.requirements is contained in (1) Branch Technical Position (BTP) Auxiliary and Power Conversion Systems Branch (APCSB) 9.5-1, "Guidelines for Fire Protection for Nuclear Power Plants," May 1976, (2) Appendix A to BTP APCSB 9.5-1, "Guidelines for Fire Protection for Nuclear Power Plants Docketed Prior to July 1, 1976," August 23, 1976, and (3) Standard Review Plan (NUREG 0800), Section 9.5-1, "Guidelines for Fire Protection For Nuclear Power Plants," July 1981. These documents provide information, staff recommendations, and guidance which may be used by the licensees to meet the requirements of 10 CFR 50.48, Appendix R, and GDC 3. These documents also refer the licensees to such national. consensus standards as American Society for Testing and Materials (ASTM) and National Fire Protection Association (NFPA) standards, for detailed guidance on implementing typical industrial fire protection features such as fire detectors, sprinkler systems, and fire barriers. 2.0 Exemption BasesSection III.G of Appendix R to 10 CFR Part 50 specifies the fire protection features needed to ensure that at least one means of achieving and maintaining safe shutdown conditions will remain available during and after any postulated fire in the_ plant. Appendix R specifies the design-~asis protective features rather than the design-basis fire. e Section III.G.2 of Appendix R requires that one train of redundant trains of cables and equipment necessary to achieve and maintain safe shutdown be maintained free of fire damage by one of the following means: (1) Separation of cables and equipment and associated non-safety circuits of redundant trains by a fire barrier having a 3-hour rating. Structural steel forming a part of or supporting such fire barriers shall be protected to provide fire resistance equivalent to that required of the barrier. (2) Separation of cables and equipment and associated non-safety circuits of redundant trains by a horizontal distance of more than 20 feet with no intervening combustibles or fire hazards. In addition, fire detectors and an automatic fire suppression system shall be installed in the fire area. (3) Enclosure of cables and equipment and associated non-safety circuits of one redundant train in a fire barrier having a I-hour rating. In addition, fire detectors and an automatic fire suppression system shall be installed in the fire area. If these provisions are not met, Section 111.G.3 of Appendix R requires that an alternative shutdown capability independent of the fire area of concern be provided. Section 111.G.3 also requires that fire detectors and a fixed fire suppression system be installed in the area of concern. These alternative requirements are not deemed to be equivalent; however, they provide adequate fire protection for those configurations in which they are accepted. Plant-specific conditions may preclude compliance with one or more of the provisions specified in Section 111.G. In such a case, the licensee must demonstrate, by means of a detailed fire hazards analysis, that existing protection or existing protection in conjunction with proposed modifications will provide a level of safety equivalent to the technical requirements of Section 111.G of Appendix R. Exemptions from fire protection requirements may be requested under 10 CFR 50.12. Generally, the staff will accept an alternate fire protection configuration on the basis of a detailed fire hazards analysis if: (1) the alternative ensures that one train of equipment necessary to achieve hot shutdown from either the control room or emergency control stations is free of fire damage; and (2) the alternative ensures that fire damage to equipment necessary to achieve cold shutdown is limited so that it can be repaired within a reasonable time (minor repair using components stored on the site); and (3) fire-retardant coatings are not used as fire barriers; and. (4) modifications required to meet Section 111.G would not enhance fire protection safety levels above that provided by either existing or proposed alternatives. The staff will also accept an alternative fire protection configuration on the basis of a detailed fire hazards analysis when the licensee can demonstrate that modifications required to meet Section III.G would be detrimental to overall facility safety, the alternative configuration satisfies the four aforementioned criteria, and the alternative configuration provides an adequate level of fire safety. 3.0 Exemption Development and Review Using the NRC guidance and applying the defense-in-depth concept, the licensees determine the fire protection features for plant safety systems and fire areas by analyzing the effects of the postulated fire relative to maintaining the ability to safely shut down the plant. A full fire hazards analysis is performed by the licensee to demonstrate that the plant will maintain the ability to perform safe shutdown functions in the event of a fire. In the fire hazards analysis the licensee must address, as a minimum, the following variables and attributes: The NRC fire protection requirements and guidance that apply. Amounts, types, configurations, and locations of cable insulation and other combustible materials. Fire loading and calculated fire severities. In-situ fire hazards. Automatic fire detection and suppression capability. Layout and configurations of safety trains. Reliance on and qualifications of fire barriers, including fire test results, the quality of the materials and system, and the quality of the installation. Fire area construction (walls, floor, ceiling, dimensions, volume, ventilation, and congestion). Location and type of manual fire fighting equipment and accessibility for manual fire fighting. Potential disabling effects.of fire suppression systems on shutdown capability. Availability of oxygen (for example, inerted containment). Alternative or dedicated shutdown capability. When the fire hazards analysis shows that adequate fire safety can be provided by an alternative approach (i.e., an approach different from the specified requirement such as the use of a I-hour fire rated barrier where a 3-hour barrier is specified), licensees that are required to meet Appendix R to 10 CFR Part 50 may request NRC approval of an exemption from the technical requirements of Appendix R to 10 CFR Part 50. Any exemption request must include a sound technical basis that clearly demonstrates that the fire protection defense-in-depth is appropriately maintained and that the exemption is technically justifted. As part of its evaluation, the licensee should provide sound technical justification if it does not propose to install or improve the automatic suppression and/or detection capabilities in the area of concern and or to implement other more restrictive fire prevention, detection, or suppression measures. Similarly, licensees that are not required to comply with Appendix R may need a license amendment or NRC staff approval of a deviation from a specific NRC guideline. The licensee must submit a technical justtfication for the alternative approach for NRC review and approval with its license amendment or deviation request. As part of its safety evaluation of the exemption request, deviation, or license amendment, the NRC staff evaluates the fire hazards analysis* and the aforementioned variables to ensure that the licensee demonstrated that an alternative approach-provides an adequate level of fire protection.