ML14325A667

Request for Additional Information Regarding License Amendment Request to Support a Measurement Uncertainty Recapture Power Uprate for Catawba, Unit 1

ML14325A667
Person / Time
Site:	Catawba
Issue date:	11/26/2014
From:	Geoffrey Miller Plant Licensing Branch II
To:	Henderson K Duke Energy Carolinas
Miller G
References
TAC MF4526, TAC MF4527
Download: ML14325A667 (6)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 November 26, 2014 Mr. Kelvin Henderson Site Vice President Catawba Nuclear Station .

Duke Energy Carolinas, LLC 4800 Concord Road York, NC 29745

SUBJECT:

CATAWBA NUCLEAR STATION, UNITS 1 AND 2: REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO SUPPORT A MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE FOR CATAWBA, UNIT 1 (TAC NOS. MF4526 AND MF4527)

Dear Mr. Henderson,

By letter d~ted June 23, 2014 (Agen~ywide Documents Access and Management System (ADAMS) Accession No. ML14176A109), Duke Energy Carolinas, LLC submitted a license amendment request to increase the Catawba, Unit 1, authorized core power level from 3,411 megawatts thermal (MWt) to 3,469 MWt, an increase of approximately 1. 7 percent rated thermal power.

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 the NRC staff's review. Enclosure 1 describes this request for additional information (RAI). In a teleconference on November 19, 2014, Duke staff agreed to a response of January 19, 2014.

If you have any questions, please call me at 301-415-2481.

(i:#'\

G. Edward Miller, Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-413 and 50-414

Enclosure:

As stated cc w/encl: Distribution via Listserv

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REQUEST FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST TO SUPPORT THE MEASUREMENT UNCERTAINTY RECAPTURE POWER UPRATE DUKE ENERGY CAROLINAS, LLC CATAWBA NUCLEAR STATION, UNITS 1 AND 2 DOCKET NOS. 50-413 AND 50-414 TAC NOS. MF4526 AND MF4527 By letter dated June 23, 2014, Duke Energy Carolinas, LLC, the licensee for Catawba Nuclear Station, Units 1 and 2 (Catawba), requested a measurement uncertainty recapture (MUR) power uprate (Agencywide Documents Access and Management System (ADAMS) Accession No. ML14176A109). The proposed revision would increase the Catawba, Unit 1, authorized core power level from 3411 megawatts thermal (MWt) to 3469 MWt, an increase of 1. 7 percent rated thermal power (RTP).

Based on the review of the amendment request, the NRC staff has determined that additional information is required regarding the MUR power uprate Vessels and Internals Integrity Branch (EVIB)- RAI 1 Paragraph (b)(1) of 10 CFR 50.61, "Fracture Toughness Requirements for Protection Against Pressurized Thermal Shock Events," requires that for each pressurized water nuclear power reactor, the licensee shall project values of RT Prs, accepted by the U. S. Nuclear Regulatory Commission (NRC), for each reactor vessel (RV) beltline material. Paragraph (a)(3) of Title 10 of the Code* of Federal Regulations (1 0 CFR) 50.61 defines the RV beltline to include the region that directly surrounds the effective height of the active core and adjacent regions of the RV that are predicted to experience suffidentneutron radiation damage to be considered in the selection of the most limiting material. RIS 20.14-11 further clarifies that the beltline is defined to include those portions of the RV ferritic materials with neutron fluence greater than 1 x 10 17 n/cm 2 (E > 1 MeV) at the end of the licensed operating period.

• A. Verify that RT Prs was calculated for all ferritic RV materials expected to receive neutron fluence greater than 1 x 1017 n/cm 2 at the end of the licensed operating period. If not, revise the RTPTS calculations in the LAR, Enclosure 2, Paragraph IV.1.C.i and Table IV.1.C-1 to include all ferritic RV materials that will receive a neutron fluence greater than 1 x 10 17 n/cm 2 at the end of the licensed operating period and submit the revised calculations to the NRC for review as a part of the management update and retrieval (MUR) LAR.

Enclosure

B. Clarify how the "bounding nozzle shell material" referred to in Table 5-42 of the Catawba 1 Updated Final Safety Report (UFSAR) correlates to the materials in the LAR, Enclosure 2, Table IV.1.C-1.

EVIB-RA12 10 CFR Part 50, Appendix G requires that P-T limits be developed to bound all ferritic materials in the RV. Further, Sections I C!nd IV.A of 10 CFR Part 50, Appendix G specify that all ferritic reader coolant pressure boundary (RCPB) components outside of the RV must meet the applicable requirements of American Society of Mechanical Engineers (ASME Code), Section Ill, "Rules for Construction of Nuclear Facility Components".

As ~clarified in RIS 2014-11, Pressure and Temperature (P-T) limit calculations for ferritic RV materials other than those materials with the highest reference temperature may define P-T curves that are more limiting because the consideration of stress levels from structural discontinuities (such as nozzles) may produce a lower allowable pressure.

Describe how the current P-T limit curves for Catawba 1 consider all ferritic components within the entire RV and the effects of neutron radiation for any locations that are predicted to 17 experience a neutron fluence exposure greater than 1x1 0 n/cm 2 (E > 1 MeV) at the end of the licensed operating period.

If the current P-T limit curves do not consider all ferritic components within the entire RV and the effects of neutron radiation for any locations that are predicted to experience a neutron fluence exposure greater than 1x1 017 n/cm 2 (E > 1 MeV) at the end of the licensed operating period, provide appropriately revised P-T limit curves td the NRC for review as a part of the MUR LAR.

EVIB- RAI3 10 CFR Part 50, Appendix G, Paragraph IV.A.1.a requires that RV beltline materials must maintain Charpy upper shelf energy (USE) throughout the operating life of the RV of no less than 50 ft-lbs, unless an equivalent margins analysis (EMA) is performed in the manner specified in 10 CFR Part 50, Appendix G, Paragraph IV.A.1.a that is approved by the NRC.

RIS 2014-11 clarifies that the beltline is defined to include all ferritic materials of the RV with a neutron fluence greater than 1 x 10 17 n/cm2 (E > 1 MeV) at the end of the licensed operating period.

A. Verify that the USE calculations for Catawba 1 include all ferritic RV materials expected to receive a neutron fluence greater than 1 x 1017 n/cm2, (E > 1 MeV). If not, update the USE calculations in the LAR, Enclosure 2, Paragraph IV.1.C.v and Table IV.1.C:..6 to 17 include all ferritic RV materials that will receive a neutron fluence greater than 1 x 10 n/cm2 at the end of the licensed operating period and submit the revised calculations to the NRC for review as apart of the MUR LAR.

B. Clarify how the "bounding nozzle shell material" referred to in Table 5-44 of the Catawba 1 UFSAR correlates to the materials in the LAR, Enclosure 2, Table IV.1.C-6.

Electrical Engineering Branch (EEEB)- RAI 1 Provide a list and brief discussion of the electrical analysis and calculations which the licensee reviewed or updated to determine that the alternate current (AC) distribution system(s) remain bounded by the existing analysis and calculations of record.

EEEB- RAI2 Provide a list and brief discussion of the electrical analysis and calculations which the licensee reviewed or updated to determine that the DC distribution system(s) [including 240/120 V AC Auxiliary Control and 120 V Vital Instrument and Control Power Systems] remain bounded by the existing analysis and calculations of records.

EEEB- RAI3 Provide a large-format copy of the current one line diagrams of the 250 V Direct Current (DC)

Auxiliary Power System, 125 V DC and 240/120 V AC Auxiliary Control Power System, and the safety-related 125 V DC and 120 V Vital Instrument and Control Power System. In addition, please provide a large-format copy of the current one line diagram of the 230 kV switchyard to which CNS Unit .1 and Unit 2 are connected.

• EEEB- RAI4 Section V.1.A states that all DC systems will continue to have adequate capacity and capability for plant operation with an MUR power uprate and are bounded by the existing analyses and calculations of record for the plant. It also states that additional load will be placed on the Electrical Computer Support System (ECS) in powering the leading edge flow meter (LEFM). Further, it states that this added load is within the rating of the ECS System.

Provide a discussion of the effects of the ECS additional load on the associated safety-related or non-safety-related buses with an MUR power uprate.

EEEB- RAIS Section V.1.D "Grid Stability" states that the power flow cases used in the generation impact study were developed from the Duke Energy internal year 2012 summer peak case. The results of Duke Energy's annual screening were used as a baseline to identify the impact of the new generation. All cases were modified to include 20 MWe of additional generation at Catawba, Unit 1. To determine the thermal impact on Duke Energy's transmission *system; the existing Catawba, Unit 1, generation was increased by 20 MWe.

Provide a summary of the power flow analysis. Confirm whether the power flow analysis also included winter loading in addition to the summer loading. If not, explain why winter loading was not considered. In addition, please provide a discussion of how the economic generation dispatch and the generator interconnection queue was addressed during the thermal impact analysis mentioned above.

EEEB- RAI6 Section 11.1.D.iii item 44 "Equipment Qualification (EQ) parameters" states that Unit 2 and Unit 1 of CNS share the auxiliary building and that there may be Unit 2 components in the auxiliary building that see environmental changes due to the Unit 1 power uprate. As a result, all components designated for Unit 1 and all components designated and applicable to both units were evaluated in the auxiliary building.

Please verify that the items in the bulleted list on page E2-27 or the LAR have been qualified or are within the CNS's dose limits and have been resolved in the corrective action program.

EEEB- RAI7 In the August 261h 2014, supplement, Duke submitted additional information related to the EQ evaluation performed on 50 components consisting of in-core thermocouples (40), potential transformers (4), fuses (4), and damper operators (2) that were to be considered prior to implementation of the MUR power . uprate. *In addition, Section 11.1.D.iii item 44

. states that CNS identified 40 enclosures containing 21 individual component types encompassing 330 total components in the auxiliary building that needed to be evaluated for post-MUR conditions. The submittal stated that these commitments were completed and that the results of the evaluation were acceptable for post-MUR EQ conditions.

Provide a summary of the results of the EQ evaluation performed on the in-core thermocouples (40), potential transformers (4), fuses (4), damper operators (2) and the 40 enclosures mentioned above and describe the impacts the results have on the CNS MUR power uprate.

ML14325A667 *Via E-mail OFFICE NRR/LPLI-1/PM NRR/LPL2-1 /LA NRR/DE/EVIB NRR/DE/EEEB NRR/LPL2-1/BC NAME GEM iller SFigueroa SRosenberg JZimmerman RPascarelli DATE 11/26/14 11/25/14 10/30/14 11/25/14 11/26/14