NRC 2009-0076, Units I & 2, License Amendment Request 241, Alternative Source Term Commitment for Seismic Evaluation

Units I & 2, License Amendment Request 241, Alternative Source Term Commitment for Seismic Evaluation

ML092540146
Person / Time
Site:	Point Beach
Issue date:	09/10/2009
From:	Meyer L Point Beach
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NRC 2009-0076
Download: ML092540146 (4)

Text

September 10, 2009 NEXBera TM ENERGVQ POINT BEACH 7

NRC 2009-0076 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Point Beach Nuclear Plant, Units I and 2 Dockets 50-266 and 50-301 Renewed License Nos. DPR-24 and DPR-27 License Amendment Reauest 241 Alternative Source Term Commitment for Seismic Evaluation

References:

(1)

FPL Energy Point Beach, LLC letter to NRC, dated December 8, 2008, Submittal of License Amendment Request 241, Alternative Source Term (ML083450683)

(2)

Public meeting on August 6,2009 between NRC and NextEra Energy Point Beach, LLC, Point Beach Extended Power Uprate and Alternate Source Term Review Planning Meeting Presentation (ML092190563)

(3)

NRC letter to Edwin I. Hatch Nuclear Plant, dated August 28, 2008, Edwin I. Hatch, Units I and 2 - Issuance of Amendment Nos. 256 and 200, Re: Alternate Source Term (TAC Nos. MD2934 and MD2935)

(ML081770071)

(4)

NextEra Energy Point Beach, LLC letter to NRC, dated May 15, 2009, Response to Request for Additional Information, License Amendment Request 241, Alternative Source Term (ML091380113)

NextEra Energy Point Beach, LLC (NextEra) submitted License Amendment Request (LAR) 241 (Reference I) to the NRC pursuant to 10 CFR 50.90. The license amendment would revise the current licensing basis to implement the alternative source term (AST) through reanalysis of the radiological consequences of the Point Beach Nuclear Plant (PBNP) Final Safety Analysis Report Chapter 14 accidents.

During the review of LAR 241, the NRC Staff expressed concern regarding the seismic adequacy of the Control Room Emergency Filtration System (CREFS) and Primary Auxiliary Building Ventilation System (VNPAB) credited in the PBNP AST analysis. In response, NextEra stated at a public meeting on August 6, 2009 (Reference 2), that a commitment to the NRC would be provided to evaluate the seismic adequacy of CREFS and VNPAB. The commitment would be consistent with the approach used for the Edwin I. Hatch Nuclear Plant to provide reasonable assurance that the credited post-accident ventilation systems would operate and retain pressure integrity during and following a seismic event (Reference 3). This letter provides a commitment to perform a seismic adequacy review of ventilation systems credited in the AST analysis. Enclosure 1 contains details on the seismic adequacy review. This letter supplements the NextEra response (Reference 4) regarding the seismic design of CREFS and VNPAB.

NextEra Energy Point Beach, LLC, 6610 Nuclear Road, Two Rivers, WI 54241

Document Control Desk Page 2 Summary of Reaulatorv Commitments The following new Regulatory Commitment is proposed:

9 A seismic adequacy review of ventilation systems credited in the AST analyses will be conducted in accordance with the guidelines provided in the Seismic Qualification Utility Group (SQUG) Generic Implementation Procedure for Seismic Verification of Nuclear Plant Equipment, Revision 2, as corrected on February 14, 1992, and in the December 2006, Electric Power Research institute (EPRI) Final Report 1014608, "Seismic Evaluation Guidelines for HVAC Duct and Damper Systems: Revision to 1007896," as applicable. This seismic verification review, including independent peer review, will be conducted on the Point Beach Units I and 2 CREFS and exhaust portion of the VNPAB system credited in the AST analyses and the associated seismic verification report will be provided to the NRC within 30 days of completion. Any required modifications identified by the review will be completed as part of implementation of the AST modifications.

The information contained in this letter does not alter the no significant hazards consideration contained in Reference (I) and continues to satisfy the criteria of 10 CFR 51.22 for categorical exclusion from the requirements for an environmental assessment.

In accordance with 10 CFR 50.91, a copy of this letter is being provided to the designated Wisconsin Official.

i declare under penalty of perjury that the foregoing is true and correct.

Executed on September 10,2009.

Very truly yours, NextEra Energy Point Beach, LLC Enclosure cc:

Administrator, Region ill, USNRC Project Manager, Point Beach Nuclear Plant, USNRC Resident Inspector, Point Beach Nuclear Plant, USNRC PSCW

ENCLOSURE I NEXTERA ENERGY POINT BEACH, LLC POINT BEACH NUCLEAR PLANT, UNITS I AND 2 LICENSE AMENDMENT REQUEST 241 ALTERNATIVE SOURCE TERM SEISMIC ADEQUACY REVIEW DETAILS The Control Room Emergency Filtration System (CREFS) and exhaust portions of the Primary Auxiliary Building Ventilation System (VNPAB) are relied on in the Alternative Source Term (AST) dose analysis to remain operable to perform radiological accident mitigation functions and retain required pressure boundaries. A commitment is made to ensure the seismic adequacy of these ventilation systems.

Previous Unresolved Safety Issue (USI) A-46 walkdowns and evaluations performed on CREFS and VNPAB provided a degree of assurance that portions of these systems are designed and installed to be seismically rugged under earthquake conditions. However, the original seismic walkdowns and evaluations of the ductwork, dampers and related hangers were not completed under an approved Seismic Qualification Utility Group (SQUG) Generic Implementation Procedure (GIP) guideline (Reference 1) developed for these components. Therefore, seismic verification walkdowns and evaluations will be conducted to re-affirm the seismic ruggedness of these systems and identify any required upgrades. These actions will provide the needed assurance that the ventilation systems credited in the AST radiological analyses remain operable and pressure boundaries are retained following a Safe Shutdown Earthquake (SSE),

as specified in Appendix A.5 of the Point Beach Nuclear Plant (PBNP) Final Safety Analysis Report (FSAR) (0.1 2g horizontal and 0.08g vertical).

A seismic verification review will be conducted in accordance with the guidelines provided in the SQUG GIP for fans, motors and heat exchangers, and the December 2006, Electric Power Research Institute (EPRI) Final Report 1014608, "Seismic Evaluation Guidelines for HVAC Duct and Damper Systems, Revision to 1007896," for ducts, dampers and hangers (Reference 2).

This seismic verification process was used at the Edwin I. Hatch Nuclear Plant to provide reasonable assurance that a post-accident ventilation system would retain pressure integrity during a seismic event (Reference 3). NextEra Energy Point Beach, LLC (NextEra) proposes to use the EPRI Final Report I01 4608 approach of utilizing the earthquake experience-based methodology, as supplemented by the peer review comments and by PBNP-specific seismic ruggedness evaluations. This same process, including independent peer review, will be conducted on PBNP, Units I and 2.

NextEra recognizes that in Reference (3), the NRC staff did not provide generic approval for use of EPRl Report No. 1007896. The EPRl report endorses the SQUG GIP-2 generic bounding spectrum which bounds the earthquake experience data. The NRC staff review of PBNP's US1 A-46 implementation program determined that the design basis ground spectra and resulting in-structure response spectra are considered conservative spectra for the purpose of the US1 A-46 resolution. The same response spectra will be used for the seismic verification of Page 1 of 2

the ventilation systems credited in the AST analyses. Therefore, the EPRl guidelines are acceptable for evaluation of CREFS and VNPAB at PBNP.

The seismic verification will use personnel that meet the SQUG GIP and EPRl report qualification requirements for Seismic Capability Engineers. The SQUG GIP and EPRl report processes will be followed, as applicable, for these work activities.

For the ducts, dampers, plenums, and housings, a determination will be made that the current duct and damper systems meet the general EPRl report requirements in order to use the seismic verification guidelines.

Walkdowns will both determine in-plant seismic adequacy of duct and damper system supports using the screening criteria for potential failure modes from the seismic experience data, and to ensure that the database is representative of the duct and damper system. Representative worst-case examples of duct supports and duct runs will be identified for analytical review.

Analytical reviews will be completed for the representative samples collected during the walkdowns. If these samples do not pass analytical review, the in-plant sample group will be expanded as appropriate and additional evaluations conducted.

The following will be documented:

e Records of walkdowns and evaluations, in accordance with EPRl Report guidelines for records; 0

Independent peer reviews of the process and walkdowns; e

Items and issues identified by peer review, as well as resolution of comments and peer review concurrence.

Upon completion of the walkdowns, outliers will be resolved either by evaluation or modification.

Outliers and outlier resolution will be described in detail and documented. Modifications identified for outlier resolution shall be implemented as part of the AST modifications scheduled for completion by the Spring 2010 refueling outage on PBNP Unit I.

References:

(1)

Seismic Qualification Utility Group (SQUG), Generic Implementation Procedure for Seismic Verification of Nuclear Plant Equipment, Revision 2, dated February 14, 1992 (2)

Electric Power Research Institute (EPRI), Final Report 1014608, Seismic Evaluation Guidelines for HVAC Duct and Damper Systems, Revision to 1007896, dated December 2006 (3)

NRC letter to Edwin I. Hatch Nuclear Plant, dated August 28, 2008, Edwin I. Hatch Nuclear Plant Unit Nos.1 and 2, Issuance of Amendments Regarding Alternate Source Term (TAC Nos. MD2934 AND MD2935) (ML081770071)

Page 2 of 2