ML12138A267

Request for Additional Information Regarding License Amendment Related to Measurement Uncertainty Recapture Power Uprate (TAC Nos. ME8213 and ME8214)

ML12138A267
Person / Time
Site:	Mcguire, McGuire
Issue date:	05/22/2012
From:	Jacqueline Thompson Plant Licensing Branch II
To:	Repko R Duke Energy Carolinas
Thompson J
References
TAC ME8213, TAC ME8214
Download: ML12138A267 (8)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 May 22,2012 Mr. Regis T. Repko Vice President McGuire Nuclear Station Duke Energy Carolinas, LLC 12700 Hagers Ferry Road Huntersville, NC 28078

SUBJECT:

MCGUIRE NUCLEAR STATION, UNITS 1 AND 2, REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT RELATED TO MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE (TAC NOS. ME8213 AND ME8214)

Dear Mr. Repko:

By letter dated March 5, 2012, Duke Energy Carolinas, LLC (the licensee), submitted a proposed license amendment to change the McGuire Nuclear Station, Units 1 and 2 (McGuire 1 and 2),

Technical Specifications (TSs). The proposed change revises the TSs to implement a measurement uncertainty recapture power uprate for McGuire 1 and 2.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the licensee's submittal and determined that additional information is needed in order to complete our review. The enclosed document describes this request for additional information (RAI). Please note that the numbering of the questions in this RAJ does not begin at the number one. A prior RAJ regarding this proposed license amendment was issued to you by letter dated April 27, 2012 (Agencywide Documents Access and Management System Accession No. ML12117A175), with RAI questions numbered one through four.

A written response should be provided to the NRC staff within 30 days of the issuance of this letter in order to support our timely review of this application. Jf you have any questions, please call me at 301-415-1119.

Sincerely, Jon Thompson. Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-369 and 50-370

Enclosure:

RAI cc w/encl: Distribution via Listserv

REQUEST FOR ADDITIONAL INFORMATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REGARDING LICENSE AMENDMENT REQUEST RELATED TO THE IMPLEMENTATION OF A MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE MCGUIRE NUCLEAR STATION, UNITS 1 AND 2 By letter dated March 5, 2012 (Agencywide Documents Access and Management System (ADAMS), Accession No. ML12082A210), Duke Energy Carolinas, LLC (Duke Energy, the licensee), submitted a license amendment request (LAR) to change the McGuire Nuclear Station, Units 1 and 2 (McGuire 1 and 2), Technical Specifications (TSs). The proposed change revises the TSs to implement a measurement uncertainty recapture [MUR] power uprate for McGuire 1 and 2.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the licensee's submittal and determined that the following additional information is needed in order to complete our review:

5. In the LAR, Enclosure 2, "Summary of [Regulatory Information Summary] RIS 2002-03 Requested Information," Section VI1.6.A, "Fire Protection Program," states that

" ... Additional building heat-up will be minimal such that currently credited fire protection manual actions will not be prevented from being accomplished by their required time ...  !!

The NRC staff requests the licensee to verify that implementation of the LAR will not require any new operator actions. If implementation of the LAR requires any new operator actions, then please describe them. (AFPB 1)

6. In the LAR, Enclosure 2, Section 47, "Safe Shutdown Fire," states that, " ... For specific site fire area, the Standby Shutdown Facility is the assured method to achieve and maintain the unit in a stable hot shutdown condition. While the plant is in the hot standby mode, damage control measures can be taken, as necessary, to restore the capability to achieve cold shutdown .... " The NRC staff requests that the licensee describe how McGuire 1 and 2 meet the 72-hour requirements contained in 10 CFR Part 50, Appendix R, Sections III.G.1.b and III.L, with increased decay heat at MUR power uprate conditions.

(AFPB 2)

7. Some plants credit aspects of their fire protection system for other than fire protection activities (e.g., utilizing the fire water pumps and water supply as backup cooling or inventory for non-primary reactor systems). If McGuire 1 and 2 credit its fire protection system in this way, the LAR should identify the specific situations and discuss to what extent, if any, the LAR affects these "non-fire-protection" aspects of the plant fire protection system. If McGuire 1 and 2 do not take such credit, then the NRC staff requests that the licensee verify this as well.

Enclosure

- 2 In your response discuss how any non-fire suppression use of fire protection water will impact the ability to meet the fire protection system design demands. (AFPB 3)

8. The LAR takes credit in several instances for administrative controls of the McGuire 1 and 2 "design change process," or "engineering change process." The NRC staff requests that the specific numbers and titles of controlling procedures be provided, along with a reference to the sections that are relevant to identifying impacted procedures, controls, displays, alarms, the Safety Parameter Display System, and other operator interfaces, the simulator, and training, so that the NRC staff can conclude its review."

(AHFB 1)

9. Section 3.6.1.2 of the McGuire 1 and 2 updated final safety analysis report (UFSAR) stipulates the criteria used to define moderate energy lines at McGuire 1 and 2.

Additionally, Section 3.6.2.2.1 outlines the criteria used to postulate through-wall cracks in moderate energy piping systems. However, the information contained in LAR, Enclosure 2,Section IV, does not include an assessment of the impact of implementation of the LAR on moderate energy piping or the postulation of moderate energy line cracks.

Based on the McGuire 1 and 2 UFSAR criteria related to moderate energy piping, state the effects of the proposed MUR power uprate on moderate energy piping, including whether the LAR results in the required postulation of additional moderate energy line cracks. (EMCB 1)

10.Section IV.1.D of RIS 2002-03 stipulates that the content of MUR power uprate LARs should include the codes of record used in the evaluations of structures, systems and components (SSCs) to determine their structural adequacy at MUR conditions. However, in the LAR, Enclosure 2, Table IV.1.D-1, it does not contain the code of record used in assessing the reactor vessel internals (RVls) or balance-of-plant (BOP) and interfacing piping systems for structural adequacy at the uprated conditions. Please state the design basis code of record for the RVls, including core support and non-core support structures, BOP piping and interfacing piping systems and confirm that the evaluations performed in support of the LAR were performed consistent with the provisions stipulated by the design basis codes of record for those SSCs identified above. (EMCB 2)

11. In the LAR, Enclosure 2,Section IV.1.A.ii, describes the impact of the proposed LAR on the reactor core support structures and vessel internals (Le., the RVls). The discussion in this section of the LAR indicates that the revised core parameters at the proposed MUR power level are bounded by the values used in the analyses of record (AOR) for the RVls when the analytical uncertainties in the AOR are considered. Confirm that the AOR related to the structural evaluation of the RVls, including all core support and non-core support structures, did not require a revision to support implementation of the LAR.

Additionally, quantify the uncertainty relied upon in the AOR to demonstrate that the calculation tolerance available in the AOR sufficiently bounds the core parameters proposed in the LAR. (EMCB 3)

12. In the LAR, Enclosure 2,Section IV.1.A.v, details the evaluation of the BOP and interfacing piping systems to determine whether these systems will maintain adequate structural integrity at the MUR power level. Please state whether the AOR for any of these

- 3 systems required revision to support the LAR (Le., identify systems which were not bounded by the current AOR). For those systems not bounded by the current AOR, identify whether the revision to the AOR was necessitated based on an increase in temperature, pressure, flow rate, or a combination of any of the three operating parameters. (EMCB 4)

13. In the LAR, Enclosure 2,Section IV.1.A.ix, discusses the review performed to evaluate the effects of the LAR on safety-related valves. The discussion in this section of the LAR focuses on the effects of MUR implementation on the pressurizer overpressure protection valves and other safety-related valves. Please address the following issues related to the safety-related valve evaluation:

a) With respect to the pressurizer overpressure protection valves, the LAR states that the current design basis event analysis is bounding and, as such, there is no adverse impact on the subject valves. Please state whether the review performed for the subject valves considered all MUR operating conditions, including normal operating conditions and abnormal operating conditions. Additionally, confirm whether the AOR for the subject valves remains bounding at MUR conditions. If the analyses are not bounded, confirm that the design basis criteria used to structurally qualify the valves remain satisfied at the proposed MUR power level.

b) For the other safety-related valves reviewed in support of MUR implementation, the information in the LAR did not identify which valves were included in this review or whether these valves were found to be structurally adequate at the proposed MUR power level, as evidenced by satisfying their respective design basis criteria. State whether any of the other safety-related valves reviewed to support MUR implementation were found to be unbounded by their current AOR. If the AOR for these valves was found to be not bounding, confirm that the respective design basis acceptance criteria remain satisfied.

(EMCB 5)

14. In the LAR, Enclosure 2,Section IV.1.B.viii, "Jet impingement and thrust forces," only discusses the impact of the LAR on the McGuire 1 and 2 leak-before-break evaluations and does not mention jet impingement nor thrust forces. In Section IV.1.B.vii it states that

" ... there is no impact on the [high energy line break] HELB analysis that was originally performed for McGuire Units 1 and 2 ...... and describes the currentAOR regarding HELBs as bounding. Please confirm that the statement in Section IV.1.B.vii applies to jet impingement and thrust forces (or other dynamic effects loadings) resulting from postulated HELBs, such that a conclusion can be made regarding whether the dynamic effects resulting from postulated HELBs remain valid at the proposed MUR power level.

(EMCB 6)

15. With regards to the structural evaluations and analyses performed to support the LAR, please confirm that all analyses and evaluations for SSCs which were within the scope of the McGuire 1 and 2 license renewal efforts were done in accordance, and consistent, with the methodologies approved and referenced in NUREG-1772, "Safety Evaluation

-4 Report Related to the License Renewal of McGuire Nuclear Station, Units 1 and 2, and Catawba Nuclear Station, Units 1 and 2." Otherwise, please state the changes for all structural evaluations and analyses performed to support the proposed MUR conditions that were not performed in accordance with NUREG-1772. Justification should also be provided with regards to the acceptability of these changes. (EMCB 7)

16. For McGuire 1, the limiting reference temperature for pressurized thermal shock (RTPTS) reported in the LAR, Enclosure 2,Section IV.1.C.i, is 203 OF for the lower shell longitudinal welds 3-442A, B, and C. The NRC staff has the following questions:

• The NRC staff found that the limiting RTPTS value for McGuire 1 in this LAR differs from that reported the licensee's license renewal LAR (LRLAR). NUREG-1772 states "Using a limiting fluence of 2.73 x 1019 n/cm 2 at EOLE [end of life extended],

the applicant's revised PTS assessment prOjected the RTPTS values for these welds [the McGuire 1 limiting weld] to be 253 of using all relevant surveillance capsule data for the heat No. 21935/12008, as obtained from docketed information from the Diablo Canyon [Power Plant], [Unit] 2 [Diablo 2] RV [reactor vessel]

material surveillance program (inclusive of fracture toughness tests performed on test specimens from Diablo 2 capsules U, X, Y, and V)." The NRC staff used the LAR fluence of 2.13 x 1019 n/cm 2 to reduce the licensee's reported LRLAR RTPTS value from 253 OF to 238 OF, but this value is still far greater than the LAR limiting RTPTS value of 203 oF. Please provide your calculations of the chemistry factors and RTPTS values from the LRLAR (253 OF) and the LAR (203 OF) and resolve this apparent discrepancy. If the resolution results in a revision of the LAR limiting RTPTS value, then Tables IV.1.C-5, IV.1.C-6, and IV.1.C-9, related to heatup and cooldown curves, need to be revised also because the LAR limiting adjusted reference temperatures (ARTs) will be changed accordingly.

• Unlike the LRLAR, where the fluence values were different for intermediate shell plate longitudinal welds 2-442A, 2-442B, and 2-442C, the LAR fluence values reported for these welds are identical. Please confirm that the peak f/uence value for the intermediate shell plate longitudinal welds 2-442A, 2-442B, and 2-442C has been used for all three welds to simplify the classification of these welds in the LAR.

Please also confirm that the similar simplification has been applied to the lower shell plate longitudinal welds 3-442A, 3-442B, and 3-442C in the LAR.

(EVIB 1)

17. For the upper-shelf energy (USE) evaluation, the LAR, Enclosure 2,Section IV.1.C.v, states that the prOjected EOLE Charpy USE values due to the MUR power uprate fluence at the one quarter RV wall thickness (Y4 T) location were 60.5 ft-Ibs for the intermediate shell longitudinal welds 2-442A, 2-442B, and 2-442C, using surveillance data, and 61.8 ft-Ibs for the bottom head ring 03 for McGuire 2. The limiting USE values reported in the LRLAR are 53 ft-Ibs for the nozzle shell plate B5011-2 for McGuire 1 and 55 ft-Ibs for nozzle shell to intermediate shell weld for McGuire 2. These apparent discrepancies involve a change of limiting materials for both McGuire units. Please explain the following:

- 5

• The nozzle shell plate B5011-2 is no longer the limiting USE material for McGuire 1 in the LAR because its fluence at the ~ T location has been revised from 1.83 x 1019 n/cm 2 (LRLAR) to 0.033 x 1019 n/cm 2 (LAR).

• The fluence at the ~ T location for the intermediate shell longitudinal welds 2-442A, 2-442B, and 2-442C of McGuire 1 decreased from 1.63 x 1019 n/cm 2 (LRLAR) to 1.269 x 10 19 n/cm 2 (LAR) indicating that higher USE value should be expected for the LAR. Instead, the USE value decreased from 72 ft-Ibs (LRLA) to 60.5 ft-Ibs.

This appears to be caused by considering additional surveillance data. Please plot all surveillance data in Figure 2 of RG 1.99, Revision 2, to support the USE decrease that was used in estimating the LAR USE value for this material.

• The nozzle shell to intermediate shell weld is no longer the limiting USE material for McGuire 2 in the LAR because its fluence at the ~ T location has been revised from 1.73 x 1019 n/cm 2 (LRLAR) to 0.043 x 10 19 n/cm 2 (LAR). Please justify this significant change. Further, the initial USE of ">71" ft-Ibs in Table IV.1.C-12 indicates that the value was not determined based on data from the Certified Materials Test Report (CMTR). Please explain how the initial USE of 71 ft-Ib was determined for the nozzle shell to intermediate shell weld of McGuire 2 and justify use of this initial USE for this weld. If this 71 ft-Ibs value was determined statistically, you must revise this value based on the "mean minus two-sigma" approach.

• The limiting USE material for McGuire 2 in the LAR is the bottom head ring 03 with an initial USE of ">71" ft-Ibs in Table IV.1.C-12. Please explain how the initial USE of > 71 ft-Ib was determined for the bottom head ring 03 of McGuire 2 and justify use ofthis initial USE for this ring. If this 71 ft-Ibs value was determined statistically, you must revise this value based on the "mean minus two-sigma" approach.

(EVIB 2)

18. For reactor core support structures and vessel internals, the Materials Reliability Program (MRP) Report 1022863 (MRP-227-A), "Pressurized Water Reactor [PWR] Internals Inspection and Evaluation Guidelines [I&E]," dated December 2011 (ADAMS Accession No. ML12017A194) was issued recently, which contains the NRC staff safety evaluation (SE) for this report. MRP-227 -A provides recommended I&E guidelines, as modified by the NRC staff, for PWR RV internals as a result of the industry effort on this issue for the past few years. The LAR, Enclosure 2,Section IV.1.A.ii, concluded that, "there is no impact, adverse or otherwise, from the McGuire Units 1 and 2 MUR uprate on the plant-specific implementation of the MRP-227 requirements." However,Section IV.1.A.ii did not mention submitting of the plant-specific inspection plan in accordance with MRP-227-A to demonstrate that the degradation of the RV internals will be managed appropriately after the LAR. Please confirm that you plan to submit the plant-specific inspection program consistent with the MRP-227 -A report guidelines, and indicate the approximate date of submittal to support the LAR effectively. (EVIB 3)

- 6

19. What is the impact of LAR on the air operated valve program for McGuire 1 and 2?

(EPTB 1)

May 22,2012 Mr. Regis T. Repko Vice President McGuire Nuclear Station Duke Energy Carolinas, LLC 12700 Hagers Ferry Road Huntersville, NC 28078

SUBJECT:

MCGUIRE NUCLEAR STATION, UNITS 1 AND 2, REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT RELATED TO MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE (TAC NOS. ME8213 AND ME8214)

Dear Mr. Repko:

By letter dated March 5, 2012, Duke Energy Carolinas, LLC (the licensee), submitted a proposed license amendment to change the McGuire Nuclear Station, Units 1 and 2 (McGuire 1 and 2),

Technical Specifications (TSs). The proposed change revises the TSs to implement a measurement uncertainty recapture power uprate for McGuire 1 and 2.

The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the licensee's submittal and determined that additional information is needed in order to complete our review. The enclosed document describes this request for additional information (RAI). Please note that the numbering of the questions in this RAJ does not begin at the number one. A prior RAJ regarding this proposed license amendment was issued to you by letter dated April 27, 2012 (Agencywide Documents Access and Management System Accession No. ML12117A175), with RAJ questions numbered one through four.

A written response should be provided to the NRC staff within 30 days of the issuance of this letter in order to support our timely review of this application. If you have any questions, please call me at 301-415-1119.

Sincerely, IRA!

Jon Thompson, Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-369 and 50-370

Enclosure:

RAI cc w/encl: Distribution via Listserv DISTRIBUTION:

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