ML063170360
| ML063170360 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 10/26/2006 |
| From: | Ertman J Carolina Power & Light Co |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| 06-0006 | |
| Download: ML063170360 (4) | |
Text
FAQ TEMPLATE Plant: Harris Nuclear Plant (HNP) FAQ # 06-0006 Submittal Date: 08-??-06 Licensee
Contact:
Jeff Ertman Tele/email 919-546-3681 NRC
Contact:
Tele/email Distribution: Check all that apply (NEI Internal Use) o FPWG o RIRWG Ei NSSS'OG o NFPA 805 TF []
subtect:
Interpretation of guidance? Yes Proposed new guidance not in NEI 04-02? Yes Details:
NEI 04-02 Guidance needing interpretation (include section, paragraph, number, and line number):
NEI 04-02 Section 4.3.2 NEI 04-02 Appendix B, Section B.2.1 Circumstances requiring guidance interpretation or new guidance:
Section 4.3.2 of NEI 04-02 Revision I discusses the process for the Nuclear Safety Performance Criteria Transition Review. This section includes the process for the safe shutdown methodology review, evaluates the existing post-fire safe shutdown analyses against the guidance provided in Section 2.42 of NFPA 805. Appendix B-2 of NEI 04-02 provides details regarding the transition review. Section 2.1 of NEI 04-02 states:
"The review should be conducted against the methodology provided in NEI 00-01.. This review is intended to ensure that the transitioning nuclear safety analysis meets basic established criteria for identification and analysis of equipment and cables. Exceptions and clarifications identified during the transition review should be documented in order to provide a well-established baseline for future changes."
During a pilot plant review of the post-fire safe shutdown methodology against NEI 00-01 methodology. It was noted that the definition of high-low pressure interface provided in NEI 00-01 Revision 1 Appendix C, is not in strict alignment with ,the definition provided in NFPA Deleted:
805 (2001 edition) section 1.6.31.
i Deleted: It is noted that the NFPA 805 Since this has historically been an area of varying interpretations, it is recommended thaat tthe text (Section 1.6.31) contains the definition of high-low pressure interface.
NEI 00-01 Revision 1 interpretation be utilized as part of the NEI 04-02 Revision 1 nuclear However, the remtainder of the NFPA 805 safety performance criteria methodology review. text does not include guidance or requirements related to high-low pressure interfaces. The only technical guidance Detail contentious points if licensee and NRC have not reached agreement on the subject is provided in Appendix B to NFPA 805, which has not been Pilot plant meetings yielded no disagreement on this topic. This is Parking Lot Item 4 from the endorsed by the NRC.¶
November 2005 Pilot Meeting (NRC meeting notes - ADAMS Accession No. ML060250034, Att. 2) and the March 2006 Pilot Meeting.
This topic has been a subject of varying interpretations for years. A consistent definition moving forward will avoid future confusion and interpretation by licensees, NRC inspectors, and NRR staff.
Potentially relevant existing FAQ numbers:
None Response Section Proposed Resolution of FAQ and the basis for the proposal:
Revise Section B.2.1 of NEI 04-02 to state (underlined section is the proposed resolution):
"Tables B-2 and B-3 of this Appendix outline a recommended method to review the acceptability of a program for transition by examining the basic components of a nuclear safety capability assessment. These worksheets organize the transition of the 'pre-transitional safe shutdown analysis' to the 'nuclear safety analysis' as follows:
- 1. Nuclear Safety Capability System and Equipment Selection
- 2. Nuclear Safety Capability Circuit Analysis
- 3. Nuclear Safety Equipment and Cable Location
- 4. Fire Area Assessment The review should be conducted against the methodology provided in NEI 00-01. This review is intended to ensure that the transitioning nuclear safety analysis meets basic established criteria for identification and analysis of equipment and cables. Exceptions and clarifications identified during the transition review should be documented in order to provide a well-established baseline for future changes.
The definition in N El 00-01 for high-low pressure inicriTces is not in strict alignment with NFPA 805 (2(0)1, edition. Section 1.6*3 1) and NI- 00-01, Revision 1, Appendix C). For the purp toseolfthe methodology review, the mcthodolomsv presented in NEI 00-01. could be used as the basis hfr acccetabihitx fo[. high-low pressure intierfaces involving downstream piLngir intersvstenlI()CAs. Reactor coolant boundary valI .es ",huose spurious opening could cause Deleted: ¶1 loss of inv'cntory that could riot be mitigated in sufficient time to achieve the nuclear safety The methodology in NEI 00-01 for post-performance criteria should be considered as part of the plant's nuclear safety analysis, and need fire safe shutdown analyses may require additional clarification if the not be evaluatCd in the samne stringent manner as hieh-los,\ pressure interfacing systems are corresponding infonnation in NFPA 805 analyzed in N I100-01. is not in strict alignment (eng., definition of high low pressure interfaces in NFPA 805, 2001 edition, Section 1.6.3 1, and If the existing licensing basis is vague or silent on the methodologies identified, then a licensing NEI 00-01, Revision 1, Appendix CQ.
For the purposes of the mnethodology basis should be clearly defined during the transition period. For example, if the existing review, the methodology in NEI 00-01 licensing basis is vague or silent on the methodology for circuit analysis (selection and/or should be used as the basis for
- 1coabls.
protection of circuits) or evaluation of the failures of circuits within a fire area (single failure, any and all, one-at-a-time, sequential/concurrent, cumulative effects) a licensing basis should be established against which changes can be assessed post transition."
Basis:
A consistent definition moving forward will avoid future confusion and interpretation by licensees, NRC inspectors, and NRR staff.
The interpretation of high-low pressure interface components is provided in NEI 00-01, Appendix C:
"Based on the above guidance, the following criterion is established to determine if a RCPB valve is considered a high/low pressure interface valve component: A valve whose spurious opening could result in a loss ofRPV/RCS inventory and,due to the lower pressurerating or other breaches such as relief valve operationson the downstream piping, an interfacingLOCA (i.e., pipe rupture in the low pressure
. piping). "
The NRC has endorsed the methodology for safe shutdown analysis in NEI 00-01 on several occasions, most notably:
NRC Regulatory Issue Summary (RIS) 2005-30, Clarification of Post-Fire Safe-Shutdown Circuit Regulatory Requirements, dated December 20, 2005 (ADAMS Accession No. ML053360069) pages 1 and 2, states:
"This RIS also gives the NRC staff's views on the use of NEI guidance document NEI 00-01, "Guidance for Post-Fire Safe Shutdown' Circuit Analysis," Revision 1 (ML050310295), in complying with Appendix R. The deterministic methodology presented in NEI 00-01, when applied in accordance with the regulatory expectations described in this RIS, is one acceptable approach to the analysis of post-fire, safe-shutdown circuits."
In addition, the Draft Generic Letter 2006-XX, NRC Generic Letter 2006-XX: Post-Fire Safe-Shutdown Circuit Analysis Spurious Actuations (May 2006, ADAMS Accession No. ML061280517), page 7, states:
"The deterministic methodology in NEI 00-01, Rev. 1 (January 2005), "Guidance for Post-Fire Safe Shutdown Circuit Analysis," Chapter 3 (including the associated appendices), for analysis of post-fire safe-shutdown circuits, in conjunction with the guidance provided in this GL, is one acceptable approach to achieving regulatory compliance with post-fire safe-shutdown circuit protection requirements for multiple spurious actuations. Licensees should assume that the fire may affect all unprotected cables and equipment within the fire area simultaneously and address all cable and equipment impacts affecting the required safe-shutdown path in the fire area. All potential impacts within the fire area should be addressed."
Section B-2.1 of NEI 04-02 also states:
"The NRC staff has reviewed Revision I of NEI 00-01 and concluded that Chapter 3 provides an acceptable way to select circuits, and Chapter 4 provides an acceptable way to determine risk- significance of circuit findings."
NEI 04-02 has been formally endorsed, with exceptions noted by Regulatory Guide 1.205, Risk-Informed, Performance-BasedFire Protectionfor Existing Light- Water Nuclear Power Plants, May 2006 (ADAMS Accession No. ML0601100174). Besides endorsement of NEl 04-02, the following statement is also provided in Section 3.3 of Regulatory Guide 1.205:
"Industry guidance document NEI 00-01, Revision 1, "Guidance for Post-Fire Safe Shutdown Circuit Analysis," used in conjunction with NFPA 805 and this regulatory guide, provides one acceptable approach to circuit analysis for a plant that has transitioned to a 10 CFR 50.48(c) licensing basis."