ML092190690
| ML092190690 | |
| Person / Time | |
|---|---|
| Issue date: | 08/07/2009 |
| From: | Klein A NRC/NRR/DRA/AFPB |
| To: | |
| Klein A, NRR/DRA, 415-2822 | |
| References | |
| Download: ML092190690 (4) | |
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1 Risk-Informed, Performance-Based Fire Protection: A U.S. Regulatory Perspective Alexander R. Klein, P.E.
Chief, Fire Protection Branch Division of Risk Assessment Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, DC 20555 United States of America Alex.Klein@nrc.gov ABSTRACT In 2004, the United States Nuclear Regulatory Commission (USNRC) amended its fire protection regulations to allow nuclear power plant licensees to voluntarily adopt a risk-informed and performance-based fire protection rule. The rule permits a licensee to use the fire protection requirements contained in the National Fire Protection Association (NFPA) Standard 805, Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants, 2001 edition, with exceptions, as an alternative to complying with Title 10 of the Code of Federal Regulations (CFR) Section 50.48(b) or the licensees fire protection license condition. Approximately one-half of the U.S.
nuclear power plants plan to adopt the risk-informed and performance-based fire protection rule. This presentation will provide a brief background discussion and will focus on USNRC perspectives on regulatory infrastructure development, experiences with the pilot plants, lessons learned, and path forward. The presentation will also discuss how the tools developed in support of a risk-informed and performance-based fire protection framework may be leveraged to enhance safety and licensees operational flexibility in other areas of plant operations.
BACKGROUND In accordance with 10 CFR 50.48(a), each operating nuclear power plant (NPP) must have a fire protection plan (FPP) that satisfies General Design Criterion (GDC) 3, Fire Protection, of Appendix A, General Design Criteria for Nuclear Power Plants, to 10 CFR Part 50, Domestic Licensing of Production and Utilization Facilities. In addition, plants that were licensed to operate before January 1, 1979, must meet the requirements of Appendix R, Fire Protection Program for Nuclear Power Facilities Operating Prior to January 1, 1979, to 10 CFR Part 50, except to the extent provided for in 10 CFR 50.48(b). Plants licensed to operate after January 1, 1979, are required to comply with 10 CFR 50.48(a), as well as any plant-specific fire protection license conditions and technical specifications.
Effective July 16, 2004, the USNRC amended its fire protection requirements in 10 CFR 50.48 to add 10 CFR 50.48(c), which incorporates by reference the 2001 Edition of NFPA 805, with certain exceptions, and allows licensees to apply for a license amendment to comply with 10 CFR 50.48(c). Subsequent editions of NFPA 805 have been issued but are not endorsed by the regulation.
2 10 CFR 50.48(c) allows licensees to adopt and maintain an FPP that meets the requirements of NFPA 805 as an alternative to 10 CFR 50.48(b) or the plant-specific fire protection license conditions. Licensees who choose to comply with 10 CFR 50.48(c) must submit a license amendment application to the USNRC, in accordance with 10 CFR 50.90, Application for Amendment of License, Construction Permit, or Early Site Permit.
There are currently 104 NPP units operating in the United States. To date, licensees for 51 of the 104 NPP units have informed the USNRC that they intend to transition their current fire protection licensing basis to NFPA 805. The USNRC is currently reviewing two license amendment requests under a pilot plant program discussed later in this paper.
REGULATORY INFRASTRUCTURE DEVELOPMENT The USNRC issues regulatory guides to describe to the public, including licensees, methods that the staff considers acceptable for use in implementing specific parts of the agencys regulations, to explain techniques that the staff uses in evaluating specific problems or postulated accidents, and to provide guidance to applicants. Regulatory guides are not substitutes for regulations and compliance with them is not required. In May 2006, the USNRC issued Revision 0 of Regulatory Guide (RG) 1.205, Risk-Informed, Performance-Based Fire Protection for Existing Light-Water Nuclear Power Plants to describe one way that the staff considers acceptable for implementing the transition to NFPA 805. In 2005, the USNRC accepted proposals from the licensees for the Shearon Harris NPP and the Oconee NPP to be pilot plants for their transition to a risk-informed, performance-based fire protection licensing basis in accordance with 10 CFR 50.48(c). In March 2009, the USNRC issued a proposed revision to RG 1.205 (issued as Draft Regulatory Guide DG-1218) for public comment. The revision incorporates lessons learned from the pilot licensees transitioning to NFPA 805. The revision also endorses portions of a Nuclear Energy Institute (NEI) document NEI 04-02, Revision 2, Guidance for Implementing a Risk-Informed, Performance-Based Fire Protection Program Under 10 CFR 50.48(c), issued April 2008, to assist licensees in adopting 10 CFR 50.48(c) and making the transition from their current FPP to one based on NFPA 805. The USNRC is currently finalizing Revision 1 to RG 1.205 and plans to issue it during the fourth quarter of calendar year (CY) 2009.
The USNRC prepared NUREG-0800, Standard Review Plan (SRP) that provides criteria that the USNRC staff uses to review requests from licensees or changes to licenses. SRP Section 9.5.1 currently focuses on the review of FPPs for deterministic applications under 10 CFR 50.48(b). In 2009, the USNRC issued a proposed new SRP Section 9.5.1.2 for public comment that provides guidance for the staff who reviews risk-informed, performance-based fire protection licensing actions submitted under 10 CFR 50.48(c). The USNRC is currently finalizing SRP Section 9.5.1.2 and plans to issue it during the fourth quarter of CY2009.
Under the current Reactor Oversight Program (ROP) USNRC inspectors periodically conduct inspections of licensee fire protection programs in accordance with published inspection procedures. Two procedures currently cover triennial fire protection inspections, one for licensees who are not transitioning to NFPA 805 and another for
3 licensees who are in the process of transitioning to NFPA 805 but who have not yet received USNRC approval for a new fire protection licensing basis under 10 CFR 50.48(c). Both of these procedures have been in use for a number of years. The USNRC has prepared a draft of a third triennial fire protection inspection procedure for licensees who have received approval for a new fire protection program based on NFPA 805. At this time, the NRC is developing additional guidance that would supplement the draft inspection procedure. The new inspection procedure will be finalized after testing its use at pilot plants.
Concurrent with the new inspection procedure development, the USNRC is also undertaking efforts to define the training recommended for inspectors conducting fire protection inspections. The NRC has updated the qualifications plans for inspectors who perform fire protection inspections. These qualification plans, documented in USNRCs inspection manual chapter 1245, identify the skills that the fire protection inspector should possess in order to perform fire protection inspections.
PILOT PLANTS AND LESSONS LEARNED The pilot process allows the USNRC to work with the two pilot plants to help refine the infrastructure (e.g., RG 1.205 and SRP) that will facilitate the transition to the new licensing basis.
Each pilot plant licensee started their transition in mid-2005. In May 2008, each pilot submitted a license amendment request (LAR) to the USNRC. During the three-year transition and LAR preparation time period, the USNRC conducted a series of Observation Visits as a joint learning process with the licensees. The Observation Visits are documented in publicly available documents. Lessons learned from the pilot and non-pilot efforts were incorporated into revisions of RG 1.205 and NEI 04-02. Additional lessons learned will be incorporated into other documents such as NUREG/CR-6850/EPRI 1011989, EPRI/NRC-RES Fire PRA Methodology for Nuclear Power Facilities.
During the three-year pilot plant process, both the USNRC staff and the licensees recognized the need for additional clarifications and guidance beyond that provided in RG 1.205 and NEI 04-02. In August 2007, the USNRC staff established the NFPA 805 Frequently Asked Question (FAQ) Process to provide timely clarifications of additional staff positions usually communicated via RG 1.205. The FAQ process is a structured avenue for licensees to seek USNRC staff interpretations and clarifications of NEI 04-02 guidance and NFPA 805 requirements. The USNRC staff holds monthly public meetings to discuss these FAQs. To date, the USNRC, licensees and NEI have resolved a majority of the FAQs. The USNRC is continuing to resolve the remaining open FAQs.
What are some of the lessons learned from the pilot plants? From the USNRC perspective, lessons learned include defining clearly the content and format of information to be submitted in an LAR, guidance for the review of engineering evaluations, treatment of the risk of prior approved recovery actions, and making clear the interface between RG 1.205 and RG 1.200, An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities. These lessons learned have been captured in a number of documents such as RG 1.205, draft SRP 9.5.1.2, NEI 04-02, resolutions to FAQs, draft inspection guidance, observation visit reports and public meeting summaries.
4 The pilot process continues today with the USNRC staffs review of the pilot LARs. The USNRC staff has issued requests for additional information (RAIs) to the pilot plants.
Responses to the RAIs are expected in August 2009. The current schedule is for the USNRC staff to complete its review of the Shearon Harris NPP LAR in the fourth quarter of CY2009; and Oconee Unit 1,2, 3 NPP LAR in the first quarter of CY2010.
LEVERAGING NFPA 805 TOOLS The USNRC intends to allow certain changes to be made to the FPP without prior NRC review and approval, once the NRC approves the transition to NFPA 805. This will reduce the regulatory burden to licensees. The NRC intends to provide this flexibility via a license condition provided that the licensee can demonstrate that the change does not increase risk or, if there is an increase, the individual change results in a risk increase less than 1 x 10-7/yr for core damage frequency (CDF) and less than 1 x 10-8/yr for large early release frequency (LERF). For each of these, the licensee must also be able to demonstrate that the proposed change is consistent with the defense in depth philosophy and maintains sufficient safety margins.
A licensee who has transitioned to NFPA 805 could leverage NFPA 805 tools to improve their ability to address emergent issues. For example, if a generic or plant specific fire protection issue is identified that licensee may be able to disposition that issue using a risk-informed approach (fire PRA model) with minimal regulatory burden. Licensees with a fire PRA model could also use the tool to improve fire risk management at low power or shutdown modes.
Licensees who have transitioned to NFPA 805 and have tools such as a fire probabilistic risk assessment (PRA) may be able to take advantage of those tools in other non-fire protection areas. For example, licensees with a fire PRA model having an acceptable level of quality could be better positioned to support and make applications under the Risk Management Technical Specification (RMTS) Initiative 4b, Risk-Informed Completion Times that permits, contingent upon the results of a plant configuration risk assessment, temporary extension of the existing completion time within a Technical Specification limiting condition of operation.
PATH FORWARD The USNRC continues with the development of a risk-informed, performance-based fire protection program. The development consists of finalizing revisions to regulatory guidance, inspection procedures, training, and completion of the pilot plant process.
This in preparation for a large number of LARs expected to be submitted by licensees in the fourth quarter of 2010. In the meantime, the USNRC staff continues to communicate lessons learned with licensees through public meetings and presentations.