ML102560291

Supplemental Information to Support Proposed License Amendment Request (LAR) - Addition of Analytical Methodology to the Core Operating Limits Report (COLR)

ML102560291
Person / Time
Site:	North Anna
Issue date:	09/09/2010
From:	Price J Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
10-523
Download: ML102560291 (11)

Text

VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 September 9, 2010 10CFR50.90 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 Serial No.

NL&OS/ETS Docket Nos.

License Nos.10-523 RO 50-338/339 NPF-4/7 VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 SUPPLEMENTAL INFORMATION TO SUPPORT PROPOSED LICENSE AMENDMENT REQUEST (LAR) - ADDITION OF ANALYTICAL METHODOLOGY TO THE CORE OPERATING LIMITS REPORT (COLR)

In a July 19, 2010 letter (Serial No.10-404), Virginia Electric and Power Company (Dominion) requested amendments, in the form of changes to the Technical Specifications (TS) to Facility Operating License Numbers NPF-4 and NPF-7 for North Anna Power Station Units 1 and 2, respectively.

The proposed LAR requests the inclusion of NRC-approved Appendix C of Dominion Fleet Report DOM-NAF-2-A, "Qualification of the Westinghouse WRS-2M CHF Correlation in the Dominion VIPRE-D Computer Code," to TS 5.6.5.b as a referenced analytical methodology.

Plant specific application of the methodology requires approval of the Statistical Design Limit (SDL) for the relevant code/correlation pair.

Thus, Dominion also requested NRC review and approval of the SDL.

In an August 23, 2010 letter, the NRC requested additional information to complete their acceptance review for the proposed licensing action.

The requested information is provided in the Attachment.

Also, a public meeting was held on September 1,2010, to discuss the NRC's request for additional information. At this meeting, Dominion and NRC staff discussed the relationship between the LAR and (a) other relevant Westinghouse and Dominion analysis methodologies and (b) the planned implementation of the Westinghouse RFA-2 fuel product at North Anna Units 1 and 2. A discussion of the relationships is also included in the attachment.

Dominion continues to request approval of the proposed amendments by July 21, 2011.

Dominion also requests a 60-day implementation period following NRC approval of the requested license amendments.

Attachment:

My Commission Expires:

Serial NO.1 0-523 Docket Nos. 50-338/339 Page 2 of.B If you have any questions or require additional information, please contact Mr. Thomas Shaub at (804) 273-2763.

Sincerely, Price resident - Nuclear Engineering COMMONWEALTH OF VIRGINIA COUNTY OF HENRICO The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by J. Alan Price, who is Vice President - Nuclear Engineering of Virginia Electric and Power Company.

He has affirmed before me that he is duly authorized to execute and file the foregoing document in behalf of that company, and that the statements in the document are true to the best of his knowledge and belief.

Acknowledged before me this C1-\\\\oday of~lfI~

,2010.

~

Response to Request for Supplemental Information Commitments made in this letter:

None GINGER LYNN MELTON Notary Public Commonwealth of Virginia 310847 My Commission Expires Apr 30.2013

cc:

U.S. Nuclear Regulatory Commission Region II Marquis One Tower 245 Peachtree Center Avenue, NE Suite 1200 Atlanta, Georgia 30303-1257 NRC Senior Resident Inspector North Anna Power Station Ms. K. R. Cotton NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 G-9A 11555 Rockville Pike Rockville, Maryland 20852-2738 Dr. V. Sreenivas NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North Mail Stop 08 G-9A 11555 Rockville Pike Rockville, Maryland 20852-2738 Mr. J. E. Reasor, Jr.

Old Dominion Electric Cooperative Innsbrook Corporate Center, Suite 300 4201 Dominion Blvd.

Glen Allen, Virginia 23060 State Health Commissioner Virginia Department of Health James Madison Building - i h Floor 109 Governor Street Room 730 Richmond, Virginia 23219 Serial No.10-523 Docket Nos. 50-338/339 Page 3 of 3

Serial No.10-523 Docket Nos. 50-338/339 ATTACHMENT RESPONSE TO REQUEST FOR SUPPLEMENTAL INFORMATION Virginia Electric and Power Company (Dominion)

North Anna Power Station Units 1 and 2

Serial No.10-523 Docket Nos. 50-338/339 Page 1 of 7 RESPONSE TO REQUEST FOR SUPPLEMENTAL INFORMATION ADDITION OF ANALYTICAL METHODOLOGY TO COLR VIRGINIA ELECTRIC AND POWER COMPANY (DOMINION)

NORTH ANNA POWER STATION, UNIT NOS. 1 AND 2

Background

By letter dated July 19, 2010 (Reference 1), Virginia Electric and Power Company (Dominion) submitted a license amendment request (LAR) for North Anna Power Station (NAPS), Unit Nos. 1 and 2.

This proposed amendment request would change the Technical Specifications (TSs) for the inclusion of U.S. Nuclear Regulatory Commission (NRC)-approved Appendix C of Dominion Fleet Report DOM-NAF-2-A, "Qualification of the Westinghouse WRB-2M CHF Correlation in the Dominion VIPRE-D Computer Code,"

to the NAPS TS 5.6.5.b as a referenced analytical methodology.

In addition to this amendment, the Dominion also requested NRC review and approval of:

1) the implementation of Dominion Topical Report VEP-NE-2-A, "Statistical DNBR Evaluation Methodology," for Westinghouse RFA-2 fuel using the VIPRE-D/WRB-2M code/correlation pair, and 2) the Statistical Design Limit (SDL) for this computer code/correlation pair, since the SDL establishes a Design Basis Limit for Fission Product Barrier.

In an August 23,2010 letter (Reference 2), the NRC provided the results of the NRC staff's acceptance review performed for the proposed LAR.

In order to make the application complete the NRC staff has requested supplemental information. To better understand the questions and NRC concerns associated with the LAR, a public meeting was held on September 1, 2010.

At this meeting, Dominion and NRC staff discussed the relationship between the LAR and (a) other relevant Westinghouse and Dominion analysis methodologies and (b) the planned implementation of the Westinghouse RFA-2 fuel product at North Anna Units 1 and 2.

The following information provides a discussion of this relationship.

The figure below provides a flowchart to further clarify these relationships and facilitate the NRC's review of the proposed LAR. The general content of Figure 1 is described below.

1. The generic evaluations for the Westinghouse RFA-2 fuel product were performed using the Fuel Criteria Evaluation Process (FCEP) defined in the NRC-approved methodology report WCAP-12488-A (Reference 3).

The approved RFA-2 fuel product represents the evolution of fuel product updates, starting with the 17x17 Vantage 5H product (Reference 4).

In References 5 through 10, Westinghouse issued a series of notification letters under the FCEP process to report assessments of the individual fuel changes.

Reference 10 specifically documents the applicability of the WRB-2M CHF correlation to the RFA-2 fuel product.

2. The NRC-approved, Dominion thermal-hydraulic methodology is contained in DOM-NAF-2-A (Reference 11) and is currently listed as a reference in the Core Operating Limits Report (COLR) in TS 5.6.5.b.19. The inclusion of the WRB-2M CHF correlation and the resultant code/correlation deterministic DNBR design limit was

Serial No.10-523 Docket Nos. 50-338/339 Page 2 of 7 approved by the NRC in Reference 12.

The LAR represents the analysis to determine the plant-specific SOL for North Anna 1

and 2,

using the VIPRE-O/WRB-2M combination.

3. The Statistical ONBR Evaluation Methodology was approved by the NRC in VEP-NE-2-A (Reference 13) and is currently listed as a COLR reference in TS 5.6.5.b.8.

As depicted in the first column of the figure, the RFA-2 fuel product has been developed and generically evaluated by Westinghouse through the FCEP process (Reference 3) to meet all the fuel design limits.

The WRB-2M CHF correlation was determined to be applicable to the RFA-2 fuel product in Reference 10. The thermal-hydraulic methodology using OOM-NAF-2-A (Reference 11) is outlined in the second column. With the inclusion of the WRB-2M CHF correlation in OOM-NAF-2-A (Reference 11), the VIPRE-D/WRB-2M code/correlation pair is applicable for analyzing the Westinghouse RFA-2 fuel.

The determination of the SOL at North Anna using the VIPRE-O/WRB-2M was performed using the NRC-approved methodology of VEP-NE-2-A (Reference 13) as seen in the third column.

Therefore, the LAR requests: 1) approval to add Appendix C of OOM-NAF-2-A to the list of COLR references, and 2) requests approval of the SOL of 1.25 at North Anna using the VIPRE-D/WRB-2M code/correlation pair for the Westinghouse RFA-2 fuel product.

Serial No.10-523 Docket Nos. 50-338/339 Page 3 of 7 Figure 1: - Roadmap for Licensing Basis of July 19, 2010 LAR SOL of 1.25 for VIPRE-OI WRB-2M at North Anna with RFA-2 fuel Add OOM-NAF-2-A, Appendix C (VIPRE-OI WRB-2M) to COLR list of approved methodoqies t------------------

LAR Submitted July 19, 2010 I

Requested Approvals:

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TS 5"6.5.b.8 VEP-NE-2-A Statistical DNBR Evaluation Methodology

-Sterti;i~al De~i~n-umit-:

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DOM-NAF-2-A VlPRE-D Fleet Report TS 5"6"5"b" 19

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DOM-NAF-2-A, Appendix C WRB-2M NRC-approved

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Fuel Criteria Evaluation Process.

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WCAP-1248B-P-A WCAP-10444-P-A,

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Addendum 2-A VANTAGE 5H Fuel Assembly

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NSD-NRC-96-4694 WRB-2 applicable 10 Modified VANTAGE 5H LPD MIcJ-gridlModified IFM (MLPDIMIFM)

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NSD-NRC-98-5796 J:

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LTR-NRC-01-44 Applicability of WRB-11 WRB-2 10 17x17 RFA-2 withlwithout IFMs

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LTR-NRC-02-55 L-WRB-2M applicable 10 17x17 RFA-2 withlwithout IFMs

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RFA-2 Fuel Product (Approved tIlrough FCEP, which is a NRC-approved pmcess)

Serial No.10-523 Docket Nos. 50-338/339 Page 4 of 7 Response to NRC Questions in August 23, 2010 Letter In the September 1, 2010 meeting noted above, Dominion noted that the questions in Reference 2 relate to aspects of the transition to RFA-2 fuel, but have no bearing on the specific request for approval in the LAR. The LAR request follows the Dominion process as stated in the NRC-approved DOM-NAF-2-A fleet report (Reference 11), which defines submittal content and requirements for the implementation of a plant-specific application of DOM-NAF-2-A.

It was agreed at the September 1, 2010 meeting that Dominion would provide written responses to the questions posed in Reference 2 to allow NRC staff review of the LAR request to proceed. The response to these questions follows.

NRC Question 1 What fraction of the NAPS core will be replaced with the Westinghouse RFA-2 fuel?

Dominion Response In a typical North Anna reload core, 64 or 65 fresh assemblies (out of a total core of 157 assemblies) are loaded. This same strategy is anticipated for reload cores designed with the RFA-2 product, such that that 64 or 65 fresh assemblies will be loaded for each cycle commencing with Cycle 23 for both units (Unit 1 in spring of 2012 and Unit 2 in spring of 2013). With this strategy, full cores of the RFA-2 fuel product would be obtained in Cycle 25 for both units.

During the transition, the remainder of the core will consist of AREVA Advanced Mark-BW fuel.

NRC Question 2 General Design Criteria (GDC) 10 of 10 CFR Appendix A as detailed in Section 4.2 of Standard Review Plan (SRP)

(NUREG-OBOO) establishes the criteria that specified acceptable design limits (SAFDLs) should not be exceeded during any condition of normal operation, including the effects of AOOs.

Provide information in the form of mechanical design report for the Westinghouse RFA-2 fuel that shall satisfy the criteria in Section 4.2 of the SRP.

Dominion Response Dominion interprets this question to have both generic and plant-specific aspects relative to the implementation of the RFA-2 fuel product at North Anna.

To the extent that the question addresses the generic evaluation of the RFA-2 fuel product, Westinghouse has performed evaluations that addressed the applicability of existing SAFDLs and DNB correlations, test results, and verification such that SRP Section 4.2 criteria are met. The generic evaluations were conducted using the NRC-approved FCEP methodology defined in WCAP-12488-P-A (Reference 3).

The RFA-2 fuel product represents the evolution of fuel product features, starting with the 17x17 Vantage 5H product (Reference 4).

In References 5 to 10, Westinghouse issued a series of notification letters under the FCEP process to report assessments of the individual fuel changes.

Reference 10 documents

Serial No.10-523 Docket Nos. 50-338/339 Page 5 of 7 the applicability of the WRB-2M CHF correlation to the RFA-2 fuel product, which is the correlation/fuel type analyzed in the LAR analysis.

The inclusion of the WRB-2M CHF correlation into the Dominion VIPRE-D code and the resultant code/correlation DNB limit(s) were previously established and approved by the NRC in DOM-NAF-2-A, Appendix C (Reference 11). The LAR includes the development of the plant-specific Statistical Design Limit (SDL) for North Anna 1 and 2, using the VIPRE-D/WRB-2M combination.

For the specific implementation of RFA-2 for use at North Anna, Westinghouse analyses will confirm that fuel thermal, mechanical and materials criteria are met.

The analyses being performed include assessment of fuel temperature, fuel rod design, spring hold down force and LOCA/seismic loads. These analyses are presently underway and will be completed prior to fuel product implementation at Unit 1 (the lead unit) in spring 2012.

NRC Question 3 Provide a plan or a discussion/analysis to satisfy the requirements of SRP Section 4.3, "Nuclear Design': that the nuclear design of the fuel assemblies, control systems, and the reactor core is performed to confirm that the SAFDLs will not be exceeded during normal operation or AOOs and that the effects of postulated reactivity accidents will not cause significant damage to the reactor coolant pressure boundary and to assure the requirements of GDG criteria 10, 11, 20, 25, 26, 27, and 29.

Dominion Response Dominion is responsible for reload nuclear design analysis for North Anna Units 1 and 2.

The analysis of reload cores containing RFA-2 fuel will be conducted using the NRC-approved methodology detailed in Reference 14.

These analyses will confirm that applicable criteria are met, for the actual core loading plans.

These analyses will be completed prior to fuel product implementation at Unit 1 in spring 2012 and at Unit 2 in spring 2013.

NRC Question 4 The proposed new Westinghouse RFA-2 fuel will be co-resident with AREVA Advanced Mark-BW fuel that will have thermal and hydraulic characteristics different from the new fuel. Provide thermal-hydraulic analyses that shall demonstrate that the Westinghouse RFA-2 fuel is hydraulically compatible with the co-resident AREVA fuel in the transition core. Analyses should demonstrate the thermal-hydraulic design and compatibility criteria prescribed in SRP Section 4.3.

Dominion Response Westinghouse analyses will confirm that hydraulic compatibility and thermal-hydraulic criteria are met for limiting mixed core configurations.

The analyses being performed include assessment of axial fit-up, grid growth, cross flow and lift force.

These analyses

Serial No.10-523 Docket Nos. 50-338/339 Page 6 of 7 will be completed prior to fuel product implementation at Unit 1 (the lead unit) in spring 2012.

NRC Question 5 The proposed new NAPS core with Westinghouse and AREVA fuel designs will constitute a "mixed core".

The licensee should provide the impact of the mixed core on the DNBR calculations to account for the differences in mechanical, thermal and hydraulic characteristics of the various fuel designs in the transition core.

Dominion Response Westinghouse analyses performed using the NRC-approved methodology of WCAP-11837-P-A will define a conservative ONBR penalty, which will be accommodated within Retained ONB Margin.

The difference between the safety analysis (self-imposed) limit for ONB and the design limit for ONB is the available Retained DNBR Margin (Reference 13). The LAR, Section 4.3, establishes the amount of Retained DNB Margin which is available for analysis of RFA-2 fuel.

These analyses will be completed prior to fuel product implementation at Unit 1 (the lead unit) in spring 2012.

Serial No.10-523 Docket Nos. 50-338/339 Page 7 of 7 References

1. Letter from J. A. Price (VEPCO) to Document Control Desk (USNRC), "Virginia Electric and Power Company, North Anna Power Station Units 1 and 2, Proposed License Amendment Request (LAR), Addition of Analytical Methodology to COLR," Serial No.10-404, July 19,2010

2. Letter from V. Sreenivas (NRC) to D. A. Heacock (VEPCO), "North Anna Units 1 and 2 Supplemental Information Needed for Acceptance of Requested Licensing Action Regarding Amendment Request -

Addition of Analytical Methodology to Core Operating Limits Report (COLR) (TAC Nos. ME4262 and ME4263)," August 23, 2010.

3. Topical Report, WCAP-12488-P-A, 'Westinghouse Fuel Criteria Evaluation Process,"

October 1994.

4. Topical

Report, WCAP-10444-P-A, "Reference Core

Report, Vantage 5

Fuel Assembly," July 1985; Addendum 1-A, March 1986; Addendum 2-A, "Vantage 5H Fuel Assembly," November 1988.

5. Letter from N. J. Liparulo (Westinghouse) to R. C. Jones (NRC), "Transmittal of Presentation Material from NRClWestinghouse Fuel Design Change Meeting on April 15, 1996," NSD-NRC-96-4694, April 22, 1996.

6. Letter from N. J. Liparulo (Westinghouse) to J. E. Lyons (NRC), "Transmittal of Response to NRC Request for Information on Wolf Creek Fuel Design Modifications,"

NSD-NRC-97-5189, June 30, 1997.

7. Letter from H. A. Sepp (Westinghouse) to T. E. Collins (NRC), "Notification of FCEP Application for WRB-1 and WRB-2 Applicability to the 17x17 Modified LPD Grid Design for Robust Fuel Assembly Application," NSD-NRC-98-5618, March 25, 1998.

8. Letter from H. A. Sepp (Westinghouse) to T. E. Collins (NRC), "Fuel Criteria Evaluation Process Notification for the 17x17 Robust Fuel Assembly (RFA) with IFM Grid Design,"

NSD-NRC-98-5796, October 13, 1998.

9. Letter from H. A. Sepp, (Westinghouse) to J. S. Wermiel (NRC), "Fuel Criterion Evaluation Process (FCEP)

Notification of the RFA-2 Design (Proprietary),"

LTR-NRC-01-44, December 19, 2001.

10. Letter from H. A. Sepp, (Westinghouse) to J. S. Wermiel (NRC), "Fuel Criterion Evaluation Process Notification of the RFA-2

Design, Revision 1 (Proprietary),"

LTR-NRC-02-55, November 13, 2002 (ADAMS Accession No. ML023190181).

11. Fleet Report DOM-NAF-2-A, Rev. 0.2-P-A, "Reactor Core Thermal-Hydraulics Using the VIPRE-D Computer Code," August 2010; including Appendix C, "Qualification of the Westinghouse WRB-2M CHF Correlation in the Dominion VIPRE-D Computer Code,"

(transmitted to the NRC for information in letter dated August 20,2010).

12. Letter from D. N. Wright (NRC) to D. A. Christian (VEPCO), "Appendix C to Dominion Fleet Report DOM-NAF-2,

'Qualification of the Westinghouse WRB-2M CHF Correlation in the Dominion VIPRE-D Computer Code'," April 22, 2009.

13.Topical Report, VEP-NE-2-A, "Statistical DNBR Evaluation Methodology," June 1987.

14.Topical Report, VEP-FRD-42-A, Rev. 2.1-A, "Reload Nuclear Design Methodology,"

August 2003.