.t. Southern Nuclear

June 15, 2017

Docket Nos.: 50-424 50-425

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001

J. J. Hutto Regulatory Affairs Director

Vogtle Electric Generating Plant- Units 1 and 2 Response to Request for Additional Information

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jjhuno@l.,outhemw com

NL-17-0912

Regarding Request to Revise Technical Specifications LCO 3.7.9 for a Change to Support Nuclear Service Cooling Water Transfer Pump Repairs

Ladies and Gentlemen:

References:

1. SNC Letter NL-17-0058, Agency Documents Access and Management System (ADAMS) Accession No. ML 170838097, Vogtle Electric Generating Plant- Units 1 and 2 Request to Revise Technical Specifications LCO 3. 7.9 for a Change to Support a Nuclear Service Water Transfer Pump Repairs, dated March 24, 2017.

2. NRC Letter, Agency Documents Access and Management System (ADAMS) Accession No. ML 17121 A441, Vogtle Electric Generating Plant, Units 1 and 2 -Request for Additional Information (GAG No. MF9495 and MF9496), dated May 16, 2017.

On March 24, 2017, in accordance with the provisions of 10 CFR 50.90, Southern Nuclear Operating Company (SNC) submitted a request for an amendment to the Technical Specifications (TS) for Vogtle Electric Generating Plant (VEGP), Units 1 and 2.

The proposed change would revise Technical Specifications (TS) Limiting Condition for Operation (LCO) 3.7.9, "Ultimate Heat Sink (UHS)" to extend the Completion Time of one inoperable nuclear service cooling water (NSCW) basin transfer pump from 31 days to 46 days. In addition, a new Condition is added to address two inoperable NSCW basin transfer pumps.

Following the submittal of the VEGP License Amendment Request, SNC received a request for additional information from the NRC on May 16, 2017 (Reference 2). Enclosure 1 provides the requested information.

This letter contains no NRC commitments. If you have any questions, please contact Ken McElroy at 205.992.7369.

U.S. Nuclear Regulatory Commission NL-17-0912 Page 2

Mr. Hutto states he is Regulatory Affairs Director of Southern Nuclear Operating Company, is authorized to execute this oath on behalf of Southern Nuclear Operating Company and, to the best of his knowledge and belief, the facts set forth in this letter are true.

Respectfully submitted,

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J. J. Hutto Regulatory Affairs Director

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My commission expires: 1- 2.- 2 0 I g

Enclosures: 1. Response to Request for Additional Information 2. Marked-Up Technical Specifications Page 3. Clean-Typed Technical Specifications Page

cc: NRC Regional Administrator, Region II NRC NRR Project Manager- Vogtle 1 & 2 NRC Senior Resident Inspector- Vogtle 1 & 2 State of Georgia Environmental Protection Division RType: CVC7000

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Vogtle Electric Generating Plant- Units 1 and 2 Response to Request for Additional Information

Regarding Request to Revise Technical Specifications LCO 3.7.9 for a Change to Support Nuclear Service Cooling Water Transfer Pump Repairs

Enclosure 1

Response to Request for Additional Information

Enclosure 1 to NL-17-0912 Response to Request for Additional Information

On March 24, 2017, in accordance with the provisions of 10 CFR 50.90, Southern Nuclear Operating Company (SNC) submitted a request for an amendment to the Technical Specifications (TS) for Vogtle Electric Generating Plant (VEGP), Units 1 and 2. The proposed change would revise Technical Specifications (TS) Limiting Condition for Operation (LCO) 3.7.9, "Ultimate Heat Sink (UHS)" to extend the Completion Time of one inoperable nuclear service cooling water (NSCW) basin transfer pump from 31 days to 46 days. In addition, a new Condition is added to address two inoperable NSCW basin transfer pumps. Following the submittal of the VEGP License Amendment Request, SNC received a request for additional information from the NRC on May 16, 2017. This enclosure to NL-17-0912 provides the requested information.

Request for Additional Information (RAI) No. 1

The alternate method in proposed TS 3.7.9 Conditions D and E utilize an NSCW pump from the opposite train, and the NSCW cross-tie connection, and a 6-inch fire hose staged for routing along the ground to the affected NSCW cooling tower. If required, the alternate method will be used to perform a safety function of transferring water to a cooling tower basin.

a. The alternate method hookup will add a static load to the existing seismic qualified connection. Please discuss any need for an evaluation of the hookup of the alternate method on the seismic qualification of the NSCW cross-tie connection and piping.

b. The licensee stated that a procedure for the alternate method would be provided before the amendment is implemented. Please describe the type of procedure to be used for the alternate method and whether the procedure would be issued in accordance with Title 1 0 of the Code of Federal Regulations, Part 50, Appendix B, "Quality Assurance Criteria for nuclear power Plants and Fuel Reprocessing Plants."

c. The 6-inch hose of the alternate method will be supplied by an NSCW pump. According to Table 9.2.1-3 of the VEGP Final Safety Analysis Report (ADAMS Accession No. ML 16330A429), a NSCW pump has a rated differential head of 230 feet and a rated flow capacity of 8600 gallons per minute. The licensee stated that the normal NSCW header pressure is 120 pounds per square inch gauge (psig) and the hose working pressure is 150 psig. However, if the actual flow from that NSCW pump during accident mitigation conditions is significantly less than normal NSCW flow, then the normal NSCW header pressure may be greater than 120 psig and possibly exceed the hose operating pressure limit. Please provide additional information on whether the hose working pressure could be exceeded, and if exceeded, any corrective actions.

SNC Response to RAI No. 1:

a. A pipe stress analysis and an evaluation of associated pipe supports for each NSCW cross-tie connection and piping will be performed to evaluate the effects of seismic and static loading for the alternate cross-tie hookup. In the interim, a pipe stress analysis and an evaluation of associated pipe

E-1

Enclosure 1 to NL-17-0912 Response to Request for Additional Information

supports was performed for the 1A NSCW Tower cross-tie connection. The conclusion of the aforementioned evaluations verifies that the addition of the cross tie piping for the alternate means of transfer from tower B to tower A has no adverse effect on the NSCW piping systems or associated supports. The configuration for all the connections are similar, therefore it is expected that results of the evaluations will be satisfactorily for the other connections. SNC has an outstanding action in the corrective action program to perform these remaining evaluations, which will be completed prior to implementation of the proposed change.

b. The type of procedure used for the alternate Method is a Standard Operating Procedure (13150) which will be issued in accordance with Title 10 of the Code of Federal Regulations, Part 50, Appendix B, "Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants."

c. The nominal shutoff head for the NSCW Pumps is approximately 370-ft or 160-psig with the system design of 200-psig. Therefore, if a deadhead condition were created the discharge pressure would likely exceed the 150-psi hose rating. The procedure will control pressure to not exceed 75-psig by means of a throttle valve that would be manually controlled to prevent over-pressurization of the hose.

Request for Additional Information (RAI) No. 2

Proposed Condition E specifies two NSCW basin transfer pumps are inoperable. When in proposed Condition E, the affected unit will also be in Condition D because a NSCW basin transfer pump is inoperable. If, while in ConditionE, the first basin transfer pump restored in proposed Required Action E.2 and the alternate method of basin transfer in proposed Required Action E.1 both transfer water into the same basin, there would be no apparent method of transfer into the other basin. Because an alternate method of basin transfer per Required Action E.1 is met, it appears possible that proposed Required Action 0.1 for the remaining inoperable NSCW basin transfer pump could be erroneously concluded to have been met.

Please clarify how the alternate method of basin transfer specified in Required Action 0.1 will perform the function of the inoperable basin transfer pump in Condition D. If appropriate, please revise the proposed TS to explicitly associate the alternate method with the function of the inoperable basin transfer pump.

SNC Response to RAI No.2:

The proposed Bases forTS 3.7.9, UHS, Actions 0.1 and 0.2 state that the alternate method must be implemented to transfer water to the affected basin. Given the scenario described in the RAI above, the alternate method would be implemented for the basin affected by the second inoperable transfer pump. In other words, the alternate method would be swapped to the basin with the inoperable transfer pump. The proposed TS 3.7.9 Required D Action has been revised to add ''to the affected basin." Enclosure 2 provides the revised mark-up page of TS 3.7.9. Enclosure 3 provides the revised clean-typed page of TS 3.7.9.

E-2

Vogtle Electric Generating Plant- Units 1 and 2 Response to Request for Additional Information

Regarding Request to Revise Technical Specifications LCO 3.7.9 for a Change to Support Nuclear Service Cooling Water Transfer Pump Repairs

Enclosure 2

Marked-Up Technical Specification Page

ACTIONS (continued)

CONDITION

D. One NSCW basin transfer pump inoperable.

Vogtle Units 1 and 2

D.1

REQUIRED ACTION

Restore tho transfer pump to OPERABLE status.

UHS 3.7.9

COMPLETION TIME

8 days

Q.2-rl- Implement an alternate 8 days method of basin transfer

AND

D.2...2

to the affected basin.

Restore the transfer pump to OPERABLE status.

3.7.9-2

NOTE A one time only ahango of tho Completion Time to 77 days is permitted until January 23, 2017 during Vogtle Unit 2, Cyale 19.

46d-t- days

Amendment No . .:f-.79-.(Unit 1) Amendment No . .:t-ea-(Unit 2)

Vogtle Electric Generating Plant- Units 1 and 2 Response to Request for Additional Information

Regarding Request to Revise Technical Specifications LCO 3.7.9 for a Change to Support Nuclear Service Cooling Water Transfer Pump Repairs

Enclosure 3

Clean-Typed Technical Specification Page

ACTIONS (continued)

CONDITION

D. One NSCW basin D.1 transfer pump inoperable.

AND

D.2

E. Two NSCW basin E.1 transfer pumps inoperable.

AND

E.2

F. Required Action and F.1 associated Completion Time not met. AND

OR F.2

UHS inoperable for reasons other than Conditions A. B, C, D, or E.

Vogtle Units 1 and 2

REQUIRED ACTION

Implement an alternate method of basin transfer to the affected basin.

Restore the transfer pump to OPERABLE status.

Implement an alternate method of basin transfer for one NSCW basin transfer pump.

Restore one NSCW basin transfer pump to OPERABLE status.

Be in MODE 3.

-------------NOTE------------LCO 3.0.4.a is not applicable when entering MODE4. ----------------------------Be in MODE 4.

3.7.9-2

UHS 3.7.9

COMPLETION TIME

8 days

46 days

24 hours

8 days

6 hours

12 hours

Amendment No. (Unit 1) Amendment No. (Unit 2)