ML19309D199

Proposed License Amendment Request: Temporary, One Time 14-Day Allowed Outage Time for Replacement of Reserve Station Service Transformer C 5KV Cables to Transfer Bus F

ML19309D199
Person / Time
Site:	Surry
Issue date:	10/30/2019
From:	Mark D. Sartain Virginia Electric & Power Co (VEPCO)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
19-424
Download: ML19309D199 (43)

Text

VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 October 30, 2019 10CFR50.90 U. S. Nuclear Regulatory Commission Serial No.: 19-424 Attention: Document Control Desk NRNGDM: RO Washington, DC 20555-0001 Docket Nos.: 50-280/281 License Nos.: DPR-32/37 VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 PROPOSED LICENSE AMENDMENT REQUEST TEMPORARY. ONE TIME 14-DAY ALLOWED OUTAGE TIME FOR REPLACEMENT OF RESERVE STATION SERVICE TRANSFORMER C SKV CABLES TO TRANSFER BUS F Pursuant to 10 CFR 50.90, Virginia Electric and Power Company (Dominion Energy Virginia) requests amendments to Surry Power Station (Surry) Units 1 and 2 Facility Operating License Numbers DPR-32 and DPR-37, respectively, in the form of a change to the Technical Specifications (TS). The proposed change adds a footnote to TS 3.16, "Emergency Power System," to allow a one-time extension of the Allowed Outage Time (AOT) in TS 3.16 Action B.2 from 7 days to 14 days. The associated TS 3.16 Basis will also be revised to include the basis for the temporary, one-time, 14-day AOT. The requested temporary 14-day AOT is needed to replace Reserve Station Service Transformer C (RSST C) 5KV cables to Transfer Bus F during the Surry Unit 2 spring 2020 refueling outage (RFO). The purpose of the RSST C 5KV cables is to provide distributed, reliable offsite power from RSST C to Transfer Bus F, which supplies the 1H and 2J emergency buses.

To facilitate the replacement of the RSST C 5KV cables to Transfer Bus F, RSST C must be removed from service. Thus, the electrical configuration of the plant for this modification is the same as it was for the RSST C replacement completed during the Unit 2 fall 2018 RFO. A temporary 21-day AOT for the RSST C replacement was approved by the NRC in TS Amendments 293/293 dated October 5, 2018. The commitments being made in support of this license amendment request (LAR), as well as the planned response for a potential failure of the alternate AC (AAC) diesel/system, are identical to those made for the temporary 21-day AOT for the RSST C replacement.

A supporting risk assessment has been performed and demonstrates that the reliability of offsite power is not significantly impacted during the proposed 14-day AOT. provides discussion and evaluation of the proposed change. The marked-up and proposed pagesJor the TS and TS Basis are provided in Attachments 4 and 5, respectively. The TS Basis changes are provided for NRC information only.

We have evaluated the proposed amendment and have determined that it does no.A 1) D /

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Serial No.* 19-424 Docket Nos. 50-280/281 Page 2 of 3 involve a significant hazards consideration as defined in 10 CFR 50.92. The basis for this determination is included in Attachment 1. We have also determined that operation with the proposed change will not result in a significant increase in the amount of effluents that may be released offsite or a significant increase in individual or cumulative occupational radiation exposure. Therefore, the proposed amendment is eligible for categorical exclusion from an environmental assessment as set forth in 10 CFR 51.22(c)(9).

Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment is needed in connection with the approval of the proposed change. The LAR has been reviewed and approved by the Facility Safety Review Committee.

Dominion Energy Virginia requests approval of the proposed change by March 31, 2020 with a 30-day implementation period.

Should you have any questions or require additional information, please contact Mr. Gary D. Miller at (804) 273-2771.

Res pectfu Ily, Mark D. Sartain Vice President- Nuclear Engineering and Fleet Support Commitments contained in this letter: See Attachment 3 for the regulatory commitments included in this letter.

COMMONWEALTH OF VIRGINIA )

)

COUNTY OF HENRICO )

The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Mr. Mark D. Sartain, who is Vice President - Nuclear Engineering and Fleet Support, 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 Q{)~ day of Odvbev ,2019.

My Commission Expires: :JV]ru,dt 3 L1.02.Z DtANEE.~

NOTARVru_..

REG.tne311'

~s& Notary Public COMMONWEALTH OF \4IRGlfM MY COMMISSION EXPIRES MARCH 31, 2022

Serial No.19-424 Docket Nos. 50-280/281 Page 3 of 3 Attachments:

1. Discussion of Change

2. AAC (Station Blackout) Diesel Corrective/Preventive Maintenance Procedures List

3. Regulatory Commitment Summary

4. Marked-up Technical Specifications and Basis Pages

5. Proposed Technical Specifications and Basis Pages cc: U.S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Avenue, NE Suite 1200 Atlanta, GA 30303-1257 State Health Commissioner Virginia Department of Health James Madison Building - 7th floor 109 Governor Street Suite 730 Richmond, VA 23219 Mr. Vaughn Thomas NRG Project Manager- Surry U.S. Nuclear Regulatory Commission One White Flint North Mail Stop 04 F-12 11555 Rockville Pike Rockville, MD 20852-2738 Mr. G. Edward Miller NRG Senior Project Manager - North Anna U.S. Nuclear Regulatory Commission One White Flint North Mail Stop 09 E-3 11555 Rockville Pike Rockville, MD 20852-2738 NRG Senior Resident Inspector Surry Power Station

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 DISCUSSION OF CHANGE Virginia Electric and Power Company (Dominion Energy Virginia)

Surry Station Units 1 and 2

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 DISCUSSION OF CHANGE TABLE OF CONTENTS 1.0 Summary Description 2.0 Detailed Description 2.1 Existing System Design and Operation 2.2 Current Technical Specifications Requirements 2.3 Reason for Proposed Change 2.4 Description of Proposed Change 3.0 Technical Evaluation 3.1 Design Basis Configuration 3.2 Temporary, One-time, 14-day AOT Configuration 3.3 Design Analysis 3.4 Branch Technical Position 8-8 3.5 Response to an AAC Diesel/System Failure and Restoration to Functional Status 4.0 Regulatory Evaluation 4.1 Applicable Regulatory Requirements/Criteria 4.2 No Significant Hazards Consideration 5.0 Precedents 6*.o Environmental Consideration 7 .0 Conclusion 8.0 References 9.0 Figures Page 1 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 DISCUSSION OF CHANGE 1.0

SUMMARY

DESCRIPTION Pursuant to 10 CFR 50.90, Virginia Electric and Power Company (Dominion Energy Virginia) requests amendments to Surry Power Station (Surry) Units 1 and 2 Facility Operating License Numbers DPR-32 and DPR-37, respectively, in the form of a change.

to the Technical Specifications (TS). The proposed change adds a footnote to TS 3.16, "Emergency Power System," to allow a one-time extension of the Allowed Outage Time (AOT) in TS 3.16 Action B.2 from 7 days to 14 days. The associated TS 3.16 Basis will also be revised to include the basis for the temporary, one-time, 14-day AOT. The requested temporary 14-day AOT . is needed to replace Reserve Station Service Transformer C (RSST C) 5KV cables to transfer bus F during the Surry Unit 2 Spring 2020 refueling outage. The purpose of the RSST C 5KV cables is to provide distributed, reliable offsite power from RSST C to the transfer bus F in the Normal Switchgear Room and to the 1H and 2J emergency buses.

To facilitate the replacement of the RSST C 5KV cables to transfer bus F, RSST C will be taken out of service. Thus, the electrical configuration of the plant for this modification is the same as it was for the RSST C replacement completed during the Unit 2 Fall 2018 .

refueling outage. The temporary 21-day AOT for the RSST C replacement was NRG approved by TS Amendments 293/293, which were issued on October 5, 2018. The commitments being made, as well as the response to failure of the alternate AC (MC) diesel/system, in this License Amendment Request are identical to those made for the .

temporary 21-day AOT for the RSST C replacement.

2.0 DETAILED DESCRIPTION 2.1 Existing System Design and Operation (Refer to Figures 9.1, 9.2, and 9.3 for the following descriptions.)

Each Surry unit has two (2) independent 4, 160V emergency buses and associated switchgear. Buses 1H and 1J supply the Unit 1 safety-related loads, and buses 2H and 2J supply the Unit 2 safety-related loads. Each bus is sized to carry 100% of the emergency load.

The safety-related buses are supplied by the RSSTs during all modes of operation (normal, start-up and shutdown). There are three RSSTs. Each RSST is sized to start up a single unit or shutdown both units. RSST A supplies bus 1J, RSST B supplies bus 2H, and RSST C supplies buses 1Hand 2J [Ref. 8.1]. The purpose of the RSST C 5KV cables is to provide distributed, reliable offsite power from RSST C to the transfer bus F in the Normal Switchgear Room and to the 1H and 2J emergency buses.

Page 2 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 The RSSTs are supplied by the System (Switchyard) Reserve Transformers (SRTs). The SRTs are designated as the primary offsite power sources. There are three (3) SRTs; SRT 1 supplies RSST A and/or RSST B, SRT 2 supplies RSST C, and SRT 4 can supply RSST A and/or RSST B, or RSST C.

The SRTs are supplied with offsite power from two independent switchyards; the 500KV switchyard supplies SRT 1, and the 230KV switchyard supplies SRT 2 and SRT 4. Offsite power can be supplied to SRT 1 from three (3) independent sources. Offsite power can be supplied to SRT 2 and SRT 4 from ten (10) independent sources [Ref. 8.1 ]. Thus, the offsite power supplies are redundant, robust, and diverse.

To ensure the possibility of two-unit simultaneous loading of the reserve station service (RSS) system is maintained within its design capability, a load shedding system was installed to remove the overloads on the RSS system. This system provides for automatic load shedding of selected non-safety-related loads from both units, which limits RSST loading to under 4000A per transformer. The scheme ensures that voltages available on the emergency buses will be within acceptable limits. A manual override switch is provided in the control room to allow manual restarting of the shed loads in a controlled manner.

Normal Outage Configuration (Refer to Figures 9.1, 9.2, and 9.3 for the following descriptions.)

The RSST power for the auxiliaries of either unit is normally supplied from SRT 1 (which is the 500/36.5KV transformer that is connected to the 500KV Bus 1), SRT 2 (which is the 230/36.5KV transformer that is connected to the 230KV Bus 4) or SRT 4 (which is the 230/36.5KV transformer that is connected to the 230KV Bus 3). The 500KV and 230KV systems are independent and provide alternative sources of reserve power.

An operating unit is required to have both emergency 4160V buses (1 Hand 1J) energized from separate primary circuits from the offsite transmission network. The TS Basis defines the primary circuits as SRTs 1, 2 and 4. Emergency bus 1J is normally supplied by SRT 1 via transfer bus D and RSST A Emergency bus 1 H is normally supplied by SRT 2 via transfer bus F and RSST C.

Electric power requirements for a unit undergoing refueling are not as explicitly stated.

However, emergency bus 2H is normally supplied by SRT 1 via transfer bus E and RSST B, and emergency bus 2J is normally supplied by SRT 2 via transfer bus F and RSST C.

Any emergency bus (1 H, 1J, 2H, 2J) may be supplied by SRT 4 via buses D, E, and F via RSST A and/or RSST B, or RSST C.

The second, independent power source is called the "dependable alternate" source. This source does not typically provide the unit with alternate power but can be made available Page 3 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> if required.

2.2 Current Technical Specifications Requirements TS 3.9, "Station Service Systems," requires the following:

• 3.9.A.1: A unit's reactor shall not be made critical without all three of the unit's 4, 160V buses energized.

• 3.9.A.5: Both of the 4, 160V emergency buses energized as explained in Section 3.16.

TS Action 3.16.B.2 requires that the unit be brought to cold shutdown after 7 days if (a)

"a primary source is not available" or (b) "specification A-4 is not satisfied".

• A primary source is defined as a circuit that supplies power through the Reserve Station Service Transformers (RSSTs). The circuits that supply power through the RSSTs are from three (3) System (Switchyard) Reserve Transformers (SRTs).

o SRT No. 1 (which is the 500/36.5KV transformer that is connected to 500KV Bus 1) o SRT No. 2 (which is the 230/36.5KV transformer that is connected to 230KV Bus 4) o SRT No. 4 (which is the 230/36.5KV transformer that is connected to 230KV Bus 3)

The 500KV and 230KV systems are independent and provide alternative sources of reserve power [Ref. 8.1 ].

• Specification 3.16.A.4 requires two physically independent circuits from the offsite transmission network to energize the 4, 160V and 480V emergency buses.

o "One of these sources must be immediately available (i.e., primary source)."

As defined above, the primary source must come from SRT Nos. 1, 2, or 4 through an RSST.

o "The other must be capable of* being made available within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />

• (i.e., dependable alternate source)."

The dependable alternate source can be made available in eight (8) hours by removing the unit from service, disconnecting its generator from the isolated phase bus, and feeding offsite power through the main step-up transformer and normal station service transformer to the emergency buses.

2.3 Reason for Proposed Change The existing RSST C 5KV cables to transfer bus F are aging plant equipment and are reaching the end of their reliable service life. In addition, the existing cables are subject to premature shield failure due to long vertical cable routes (-80 feet vertical), which can cause shield slippage over time and eventual insulation breakdown and failure. Such a Page 4 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 failure would cause a loss of the offsite power source to the 1H and 2J emergency buses and would require both units to enter a 7-day AOT.

The RSST C 5KV cables' replacement activities include installation of raceway, penetrations, fire barriers, and supports, as well as the installation and termination of the electrical cables. As much as possible, these activities will be completed prior to the Spring 2020 Unit 2 refueling outage. Cable termination/tie-in, as well as Tan Delta testing, will be performed during the outage. Currently, the RSST C 5KV cables are routed up the side and onto the roof of the Turbine Building and into the Unit 1 Normal Switchgear*

Room. The new routing for the RSST C 5KV cables will be through the Unit 2 Turbine Building and into the Unit 1 Normal Switchgear Room. The 5KV cables for RSST A and RSST B are routed through the Unit 1 Turbine Building and into the Unit 1 Normal Switchgear Room. The new routing for the RSST C 5KV cables to transfer bus F maintains adequate physical separation and independence; thus, compliance with GDC-17 is maintained.

Replacement of the RSST C 5KV cables will assure continued dependable and safe generation of electrical power. The proposed temporary 14-day AOT is needed to allow sufficient time to replace the RSST C 5KV cables while permitting Unit 1 to maintain normal power operation. The temporary 14-day AOT also precludes the unnecessary transient of shutting down Unit 1 and the attendant risk. A detailed evaluation of the required RSST C 5KV cables' replacement activities determined that 14 days is sufficient time to complete the replacement, including reasonable margin. The requested temporary, one-time, 14-day AOT will be implemented during the Unit 2 Spring 2020 refueling outage.

2.4 Description of Proposed Change Dominion Energy Virginia proposes to add the following temporary, one-time, TS requirements and additional wording to the TS Basis. The TS 3.16 Basis revision is provided to the NRG for information.

TS 3.16.B.2 is to be revised to add a one-time extension of the primary source Allowed Outage Time from 7 days to 14 days:

B. During POWER OPERATION or the return to power from HOT SHUTDOWN, the requirements of specification 3.16.A may be modified by one of the following:

2. If a primary source is not available, the unit may be operated for seven (7) days provided the dependable alternate source can be OPERABLE within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. If specification AA is not satisfied within seven (7) days, the unit shall be brought to COLD SHUTDOWN. (*)

Page 5 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1

(*) To facilitate the replacement of the Reserve Station Service Transformer C 5KV cables to transfer bus F during the Spring 2020 Unit 2 refueling outage, the use of a temporary, one-time, 14-day allowed outage time (AOT) is permitted for the unavailability of a primary source. Prior to entry into and during the 14-day AOT, the following actions shall be taken:

• Within 30 days prior to entering the temporary 14-day AOT, functionality of the Alternate AC (MC) System, (i.e., the supplemental power source) shall be verified.

• During the 14-day AOT, the functionality of the MC System shall be checked once per shift. If the MC System becomes non-functional at any time during the 14-day AOT, it shall be restored to functional status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, or the unit shall be brought to HOT SHUTDOWN within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

TS 3.16 Basis is to be revised in support of the temporary footnote to TS 3.16.B.2:

Reserve Station Service Transformer (RSST) C is the primary offsite power source for the 1H and 2J Emergency Buses via transfer bus F. To facilitate the replacement of the RSST C 5KV cables to transfer bus F during the Spring 2020 Unit 2 refueling outage, Technical Specification 3.16.B.2 is modified by a footnote permitting the use of *a temporary, one time, 14-day allowed outage time (AOT). The 14-day AOT will permit Unit 1 to continue to operate for 14 days. While RSST C is unavailable to facilitate the replacement of the RSST C 5KV cables, transfer bus F will be powered from the dependable alternate source (i.e., backfeed through the Unit 2 Main Step-up Transformer/Station Service Transformer 2C). The backfeed power supply will allow transfer bus F to perform its normal function while the RSST C 5KV cables are being replaced. Prior to entry into and during the 14-day AOT, the following actions shall be taken:

1. Within 30 days prior to entering the temporary 14-day AOT, functionality of the Alternate AC (MC) System (i.e., the supplemental power source) shall be verified.

2. During the 14-day AOT, the functionality of the MC System shall be checked once per shift. If the MC System becomes non-functional at any time during the 14-day AOT, it shall be restored to functional status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, or the unit shall be brought to HOT SHUTDOWN within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

The verification of functionality of the MC System prior to entering the temporary 14-day AOT will be based on the previous satisfactory quarterly test. The once per shift functionality check will be performed during shiftly operator rounds.

In addition to verifying and checking functionality of the MC System prior to and during Page 6 of 26

Serial No.19-424 Docket Nos. 50-280/281.

RSST C Cable Replacement LAR

. Attachment 1 the temporary 14-day AOT, the following actions will be taken:

• Weather conditions will be monitored, and preplanned maintenance will not be scheduled if severe weather conditions are anticipated.

• The system load dispatcher will be contacted once per day to ensure no significant grid perturbations (high grid loading unable to withstand a single contingency of line or generation outage) are expected during the temporary 14-day AOT.

• Component testing or maintenance of safety systems and important non-safety equipment in the offsite power systems that can increase the likelihood of a plant transient (unit trip) or LOOP will be avoided. In addition, no discretionary switchyard maintenance will be performed.

• TS required systems, subsystems, trains, components, and devices that depend on the remaining power sources will be verified to be operable and positive measures will be provided to preclude subsequent testing or maintenance activities on these systems, subsystems, trains, components, and devices.

• Operation or maintenance of plant equipment when its redundant equipment or train is out of service will be controlled in accordance with procedure OP-SU-601, "Protected Equipment". The Unit 1 steam-driven Auxiliary Feedwater Pump will be controlled as "Protected Equipment" during the temporary 14-day AOT.

• The status of the AAC diesel generator, EDGs, RSST A and RSST B will be monitored once per shift.

3.0 TECHNICAL EVALUATION

Two independent emergency 4160V buses and switchgear are provided for each Surry unit. Each bus is sized to carry 100% of the emergency load and may be energized by either onsite .or offsite power supplies. The onsite and offsite power supplies are both independently capable of supplying power to the Engineered Safeguards Features (ESF) equipment. This capability is maintained even in the event of a failure of any single active component in either system.

3.1 Design Basis Configuration Dominion performed analyses in accordance with NRG Generic Letter 79-36, dated August 8, 1979, entitled "Adequacy of Station Electrical Distribution System Voltages," to determine the adequacy of the Surry electrical distribution system. As described in UFSAR Section 8.5, the review consisted of:

1. Analytically determining the capacity and capability of the offsite power system and Page 7 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 onsite distribution system to automatically start as well as operate all required loads within their required voltage ratings in the event of: (1) an anticipated transient, or (2) an accident (such as a LOCA) without manual shedding of any electric loads.

2. Determining if there are any events or conditions which could result in the simultaneous or cons.equential loss of both required circuits from the offsite network to the onsite electrical distribution system and thus violate the requirement of General Design Criterion 17.

The analyses concluded that the Surry Units 1 and 2 offsite power system and the onsite distribution system can provide acceptable voltages for worst-case station electric load and grid voltages.

The voltage level and current loading of the station distribution buses .are displayed in the control room. The status of the switchyard breakers and the source of reserve station power are readily available to the operator. Indicating lights show the sou_rce of power to each bus. Alternate sources may be manually selected by the operator, but prearranged automatic transfer takes place on failure of the normal source.

Thus, the existing configuration can support the emergency loads, with allowance for a single failure, under worst-case conditions. As discussed in the design analysis section, substituting the Unit 2 dependable alternate source for one primary source during the Spring . 2020 Surry Unit 2 refueling outage (temporary, one-time, 14-day AOT configuration) does not compromise this capability.

3.2 Temporary, One-time, 14-day AOT Configuration During the temporary 14-day AOT, Unit 1 will be in the POWER OPERATION mode and Unit 2 will be in the COLD SHUTDOWN, REFUELING SHUTDOWN, or REFUELING OPERATION mode with RSST C out of service to facilitate the replacement of the RSST C 5KV cables to transfer bus F. The AOT configuration maintains redundant and physically separate offsite primary power supplies to transfer buses D (via RSST A) and E via (RSST B) (Figures 9.2 and 9.3). The only difference is the AOT configuration replaces the normal primary power supply to transfer Bus F (normally via RSST C) with a single offsite backfeed through the Unit 2 Main Step-up Transformer and Station Service Transformer (SST) 2C. Thus, emergency buses 1H, 1J, 2H, and 2J are energized from an offsite power source in accordance with TS 3.9. However, emergency buses 1H and 2J are fed from the dependable alternate source instead of a primary source. As discussed in the design analysis section, the AOT configuration can support the emergency loads, with allowance for a single failure, under worst-case conditions.

The operating unit (Unit 1) will maintain a preferred offsite supply for emergency bus 1J from the 230KV switchyard (SRT 4 to bus 7 to RSST A) to ensure that a failure in the 500KV switchyard cannot affect both Unit 1 emergency buses (1J and 1H). The supply.

for emergency bus 1H will be from the Unit 2 designated dependable alternate source Page 8 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 (offsite power from the 500KV switchyard through the Main Step-up Transformer and normal SST 2C to transfer bus F to bus 1H).

The refueling unit (Unit 2) will maintain a preferred offsite supply for emergency bus 2H from the 230KV switchyard (SRT 4 to bus 7 to RSST B) to ensure that a failure in the 500KV switchyard cannot affect both Unit 2 emergency buses (2J and 2H). The supply for emergency bus 2J will be from the Unit 2 designated dependable alternate source (offsite power from the 500KV switchyard through the Unit 2 Main Step-up Transformer and normal SST 2C to transfer bus F to bus 2J).

During the temporary 14-day AOT, the one-time only configuration and operating restrictions are as follows:

1. Two Unit Load Shed Circuit (LSR1) defeated.

2. Auto Start Blocking circuit (LSR2) in operation.

3. RSST C out of service.

4. Transfer bus D supplied by RSST A (bus 1J and normal configuration and loads).

5. Transfer bus E supplied by RSST B (bus 2H and normal configuration and loads).

6. Transfer bus F supplied by Unit 2 SST 2C (AOT configuration) with the following loads:

• Bus 1H: normal operating load.

• Bus 2J: normal outage load plus Residual Heat Removal (RHR) pump.

• Bus 1C: will transfer to bus F if unit trips.

• Bus 2C: Feedwater pump, Condensate, Bearing Cooling pump, 480V lighting - on; Reactor Coolant Pump, High Pressure Heater Drain, Low Pressure Heater Drain

- off.

Thus, in the one-time AOT configuration the dependable alternate source (Unit 2 backfeed) is immediately available (i.e., it does not require an 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> window for connection), because it is already connected for the Unit 2 refueling outage, and the onsite power supplies remain available to emergency buses 1H and 2J because onsite power supplies to transfer bus F are downstream of RSST C.

Defense-In-Depth is preserved because each emergency bus is continuously supplied from a physically and electrically independent offsite source, each emergency bus can be supplied by an emergency diesel generator, and each switchyard (230KV and 500KV) has multiple sources of offsite power.

3.3 Design Analysis There are two (2) emergency buses for each unit; buses 1H and 1J (Unit 1), and buses 2H and 2J (Unit 2) [Ref. 8.1]. During the temporary 14-day AOT, while the RSST C 5KV cables to transfer bus Fare being replaced, buses 1J and 2H will continue to be energized from SRT 4, which is a designated primary offsite power source. Buses 1H and 2J will Page 9 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 be energized from Main Step-up Transformer 2, which is the Unit 2 designated dependable alternate source. While this is a reliable source, which is from a separate switchyard and can support the combined Unit 1 and Unit 2 loads, it is not a designated primary source. Under these conditions, Technical Specification (TS) 3.9 is met, but TS 3.16.B.2 would normally require that Unit 1 be brought to COLD SHUTDOWN after 7 days into the RSST C 5KV cables' replacement activities. However, since emergency buses 1H and 2J will continue to be supplied by a separate and reliable power source, and the other features of the offsite and onsite power systems are unchanged and unaffected, it is reasonable and prudent to request a temporary 14-day AOT on a one-time basis to eliminate the need for an unnecessary Unit 1 transient (i.e., bringing Unit 1 to COLD SHUTDOWN until RSST C is returned to service).

For the AOT, buses 1H and 2J will be fed from the Unit 2 dependable alternate source.

Buses 1J and 2H will be supplied from the circuits between the offsite transmission network and the onsite Class 1-E electrical power distribution system as identified in Table 3.3-1 below. (See Figures 9.1, 9.2, and 9.3.)

Table 3.3-1: Temporary 14-day AOT Available Offsite Power Circuits Emergency Available Transmission Available Offsite Power Station Bus Ali!::inments Network Circuits Transformer Bus 1H Temporary 14-day SOOKV Main Step-up Transformer (MT) N/A AOT Only Switchyard 2 =>SST 2C => Transfer Bus F=> Emerqencv Bus 1H Bus 1J Primary Offsite SOOKV SRT 1 => RSST A=> Transfer SRT 1' Source* Switch yard Bus D=>

Emerqencv Bus 1J Alternate Offsite 230KV SRT 4 => RSST A=> Transfer SRT4 Source* Switch yard Bus D=>

Emerqencv Bus 1J Dependable 230KV MT 1 => SS TX 1A =>Transfer N/A Alternate Offsite Switchyard Bus D=> Emergency Bus 1J Source Bus 2H Primary Offsite 500KV SRT 1 => RSST B=> Transfer SRT 1 Source* Switch yard Bus E=>

Emerqencv Bus 2H Alternate Offsite 230KV SRT 4 => RSST B=> Transfer SRT4 Source* Switch yard Bus E=>

Emergency Bus 2H Dependable SOOKV MT 2 => SS TX 28 => Transfer N/A Alternate Offsite Switch yard Bus E=> Emergency Bus 2H Source Bus 2J Temporary 14-day 500KV MT 2 =>SST 2C => Transfer Bus N/A AOT Only Switchvard F=> Emerqencv Bus 2J Table 3.3-1 Notes

• During the temporary 14-day AOT, in order to maintain separation between the qualified offsite sources, buses 1J and 2H will be supplied from the 230KV switchyard (230KV switchyard offsite source SRT 4) instead of the 500KV switchyard (500KV offsite source SRT 1).

Page 10 of 26

Serial No.19-424 Docket Nos. 50-280/281

. RSST C Cable Replacement LAR

.Attachment 1 ESF equipment will continue to be powered from two independent emergency buses.

Sh.ould all offsite power sources fail, reliable onsite power .is ensured by the emergency diesel generators (EDGs) and/or the AAC System. ESF equipment can be manually operated from the control room.

Each emergency bus provides power to the following ESF equipment:

1. One Containment Spray Pump

2. One Charging Pump (100% capacity)

3. One Low-Head Safety Injection Pump (100% capacity)

4. One Inside Recirculation Spray Pump (100% total capacity)

5. One Outside Recirculation Spray Pump (100% total capacity)

6. One Motor Driven Auxiliary Feedwater Pump

7. One Motor Control Center for valves, instruments, control air compressor, fuel oil pumps, etc.

8. Control Area HVAC equipment (two air recirculating units, one water chilling unit, one service water pump, and one chilled water circulating pump)

9. One Charging Pump Service Water Pump In addition, as described in UFSAR Section 8.4.1, a load shedding scheme is currently implemented to alleviate potential low-voltage profile conditions during combined Units 1 and 2 operation using the RSSTs only .. The existing load shedding scheme is not altered by the AOT configuration.

Nevertheless, in order to provide additional protection for the offsite power supplies to the emergency power buses, restrictions will be imposed while the emergency buses are in the temporary 14-day AOT configuration, as described in Section 3.2.

3.4 Branch Technical Position (BTP) 8-8 The NRG has provided the requirements for onsite and offsite power sources AOT extensions in BTP 8-8 [Ref. 8.2].

Risk Assessment "Consistent with the Commission's final policy statement, it is expected that a license amendment request for an onsite or offsite AOT extension will contain a PRA assessment."

A risk assessment has been performed for the temporary, one-time, 14-day AOT configuration. A fault tree analysis was used to assess the reliability of offsite power supplies to transfer bus F and to evaluate conditional reliability in a configuration where the primary offsite supply from RSST C is unavailable to facilitate the replacement of the Page 11 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 RSST C 5KV cables to transfer bus F. The assessment provided the following risk insights:

• The overall reliability of offsite power supply to transfer bus F is only marginally affected by unavailability of RSST C. This is because catastrophic grid and weather disturbances are the dominant contributors to transfer bus F reliability (90% of unreliability). These contributors have the consequence of rendering all offsite power supplies to transfer bus F unavailable for extended periods of time, regardless of the number of available connections from the switchyard to transfer bus F. *

• The overall probability that all offsite power would be lost to transfer bus F during a 14-day period is very low (estimated to be approximately 3E-04 ). There are no components in these offsite sources that have high unreliability.

• Station defense-in-depth to loss of offsite power is not significantly impacted by rendering the primary RSST C power supply unavailable. In addition to the two alt~rnate backfeed power supplies, two EDGs are available to respond to a loss of power to transfer bus F. Transfer buses D and E are also available to provide power to the 100% redundant 1J and 2H emergency buses.

• No unique vulnerabilities were identified with alternate backfeed power sources which require special attention.

This assessment demonstrates that the reliability of offsite power to transfer bus F is not significantly. impacted in a configuration where the primary offsite source via RSST C is unavailable and supports the proposed temporary 14-day AOT.

During the 14-day temporary AOT, the increase in risk will be assessed and managed in accordance with the requirements of 10CFR50.65(a)(4 ). Online risk for Surry Unit 1 will be assessed using a PRA model dedicated to the purpose of performing configuration risk analysis. Shutdown risk for Surry Unit 2 will be managed in accordance with Surry's shutdown risk management program. Configurations that approach or exceed the limits defined in NUMARC 93-01 are identified and either avoided or addressed by risk management actions. Emergent configurations are identified and analyzed by the on-shift staff for prompt determination of whether risk management actions are needed.

Defense-In-Depth, AAC Supplemental Power Source*

A supplemental power source should be available as a backup to the inoperable EDG or offsite power source, to maintain the defense-in-depth design philosophy of the electrical system to meet its intended safety function."

In response to 10 CFR 50.63, the Alternate AC (AAC) system was installed to provide ac power to one emergency bus on each unit during a Station Blackout (SBO) event. The AAC System is non-safety related and is designed in accordance with Regulatory Guide 1.155 and NUMARC 87-00, Appendix 8.2.

Page 12 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 As described in UFSAR Section 8.4.6, the electrical design consists of a single 4160V ac diesel driven generator with a continuous rating of 3300 kW and a 2000-hour rating of 3640 kW. The generator is connected to the station via 4KV buses OM and OL. Bus OL is in the Unit 2 normal switchgear room and provides connection from bus OM to transfer buses D and E, which in turn allows connection to emergency buses 1J and 2H, respectively. The diesel generator can provide power to the emergency buses within 10 minutes of determining that an SBO event has occurred and is sized to carry the loads necessary to bring both units to a safe shutdown condition and maintain them in a safe shutdown condition for the postulated 4-hour SBO event duration.

Following the loss of power on either transfer bus D or E in conjunction with the loss of power on transfer bus F, the diesel generator receives an automatic start signal.

Momentary trip signals to breakers associated with the OM and OL buses ensure that the AAC System is initially isolated. Once the generator has reached proper speed and voltage, breakers automatically close to power buses OM and OL. Manual action is then required to energize transfer buses D or E. The normal power supply to the Technical Support Center (TSC) uninterruptible power supply (UPS) and the TSC motor control center (MCC) is the 2C2 Load Center that can be supplied by the SST 2C or from RSST C (not available during AOT) via transfer bus. Following a loss of the normal power supply, the TSC UPS can be powered from the AAC

• System via either transfer bus D or E following manual breaker re-alignment. Following a loss of the normal power supply, the TSC MCC can be powered from the AAC System via transfer bus D following manual breaker re-alignment.

The AAC diesel generator is independent from the emergency diesel generators. The AAC diesel generator and its auxiliaries are housed in a separate building located south of the Radwaste Facility; The air start system contains sufficient capacity for 5 starts and the fuel oil system for the AAC diesel contains sufficient fuel to operate the diesel generator at 3640 kW for the postulated 4-hour SBO duration. To maintain the system in a standby state, a keep warm system consisting of a jacket water heater with a circulating pump and a lube oil heater with a circulating pump. An ungrounded 125V de system is provided for the 4KV and 480V ac switchgear controls, diesel generator controls, and generator protection.

The temporary 14-day AOT configuration does not challenge the defense-in-depth provisions for a loss of offsite power. As shown in Figure 9.2, each emergency bus will continue to be backed up by an EOG and/or the AAC System DG.

a) Emergency Bus 1J is backed up by EDG 3 and the AAC DG

• b) Emergency Bus 1H is backed up by EOG 1 c) Emergency Bus 2H is backed up by EOG 2 and the AAC DG d) Emergency Bus 2J is backed *up by EOG 3 Temporary 14-day AOT Duration The requested temporary, one-time, 14-day AOT is needed to replace the RSST C 5KV Page 13 of 26

i Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 cables to transfer bus F. The replacement activities are discussed in Section 2.3. The estimated time to complete the replacement is approximately 6.5 days as shown in the schedule below.

Table 3.4-1: Activity Schedule for Replacement of the RSST C 5KV Cables Activity Activity Duration Elapsed Time No. Activity Description (Days - Hours) (Days - Hours) 1 Enter temporary 14-day AOT - 0-0 Tagout and disconnect 2 1-2 1-2 existing cables Install termination on new 3 3 - 16 4 - 18 cables Tan Delta testing and 4 land leads 1-6 6-0 Clear tags and exit 5 0-8 6-8 temporary 14-day AOT LOOP Coping Capability During Temporary 14-day AOT The capabilities for coping with a loss of offsite power (LOOP) are not affected by the

.temporary 14-day AOT configuration.

Information Notice 85-91, Load Sequencers for Emergency Diesel Generators, identified a potential problem with the diesel loading sequence if a LOOP should occur subsequent to a LOCA. Dominion Energy Virginia evaluated this situation with respect to EOG loading even though the Surry licensing basis considers the LOOP to occur coincident with the LOCA. The evaluation identified that, after implementation of appropriate modifications to emergency diesel sequencing logics, a LOOP subsequent to a LOCA would not result in overloading of the EDGs.

SBO Coping Capability during Temporary 14-day AOT The capabilities for coping with an SBO are not affected by the AOT configuration.

As discussed above, the AAC can provide power to the emergency buses within 10 minutes of determining that an SBO event has occurred and is sized to carry the loads necessary to bring both units to a safe shutdown condition and maintain them in a safe shutdown condition for the postulated 4-hour SBO event duration.

Surveillance Testing "The TS must contain Required Actions and Completion Times to verify that the supplemental AC source is available before entering extended AOT."

The following requirements have been included in the temporary 14-day AOT footnote to TS 3.16.B.2:

Page 14 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1

• Within 30 days prior to entering the temporary 14-day AOT, functionality of the Alternate AC (AAC) System (i.e., the supplemental power source) shall be verified.

• During the 14-day AOT, the functionality of the AAC System shall be checked once per shift. If the AAC System becomes non-functional at any time during the 14-day AOT, it shall be restored to functional status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, or the unit shall be brought to HOT SHUTDOWN within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

The verification of functionality of the AAC System prior to entering the temporary 14-day AOT will be based on the previous satisfactory quarterly test. The once per shift functionality check will be performed dudng shiftly operator rounds.

Regulatory Commitments Additionally, the staff expects that the licensee will provide the following Regulatory Commitments:

The regulatory commitments required by BTP 8-8 are included in Attachment 3.

3.5 Response to an AAC Diesel/System Failure and Restoration to Functional Status If a failure of the AAC diesel/system occurs during the proposed temporary 14-day AOT, it will be. identified either by Operations rounds performed once a shift using O-LOG-OS-001 R, Outside Logs, or by Main Control Room annunciator O-WD-D2, AAC System Alarm. The Annunciator Response Procedure O-WD-D2 would be used in conjunction with Procedure O-OP-AAC-002, AAC System Alarm Response, to address the condition. Procedure O-OP-AAC-002 provides specific instructions for operator response to local alarms on the AAC Diesel Generator Annunciator Panel. Individual attachments provide diagnostic actions associated with individual AAC system parameters to facilitate determination of the cause of the alarm and to initiate corrective actions.

A condition that renders the AAC diesel/system nonfunctional would be addressed based upon the nature of the failure. Numerous procedures provide guidance to respond to an AAC diesel/system failure. Failure of the AAC diesel/system, as well as failure of supporting equipment (e.g., starting air, blackout lube oil, etc.), would be resolved by removing the affected . component from* service using Procedure O-MOP-AAC-001, Removal from Service of_the AAC Diesel Generator, and completing the necessary repairs. Numerous corrective/preventive maintenance procedures exist and could be used to restore the functionality of the AAC diesel/system based upon the nature of the failure and the required repair. A list of these procedures is provided in .

Page 15 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 Depending on the failure mode and required repair, functionality may be restored after repairs are completed and may not require additional testing. If additional testing is required, Procedure O-OSP-MC-001, Quarterly Test of 0-AAC-DG-OM, Alternate AC Diesel Generator, or Procedure O-OP-MC-001, AAC Diesel Generator Operation, would be used to demonstrate functionality. Following repairs, Procedure O-MOP-MC-002, Return to Service of the AAC Diesel Generator, would be used for the return to service.

Additional procedures are also available to support the repair and return to service of a nonfunctional MC diesel/system. Procedure ER-M-EDG-1001, Diesel Generator Reliability Program, addresses the Emergency Diesel Generators (EDGs) and the MC diesel/system and provides guidance regarding the initial response to a failure, including initiation of the quarantine, troubleshooting, and corrective maintenance processes.

Procedure GMP-019, AAC Diesel Failure Response and Troubleshooting Guideline, also provides instructions for MC diesel failure response and troubleshooting, including assessment of initial symptoms of the problem, obtaining vendor support, and review of previous failures for a synopsis of the failures and troubleshooting actions. While Procedure MA-M-DQT-1001, Dominion Diesel Quality Team, establishes guidance for proper preventive/predictive maintenance practices and scheduling/execution with a focus on improved EOG and MC diesel reliability, it also includes information regarding the periodic review of potential EOG issues that could provide insights relative to an MC diesel failure.

In summary, the nature of an MC diesel/system failure will dictate the procedures and specific course of action required to restore MC diesel/system functionality. ,As discussed above, there are numerous procedures available for reference and use in responding to an MC diesel/system failure and restoring MC diesel/system functionality.

4.0 REGULATORY EVALUATION

As noted above, the proposed change revises the Surry Units 1 and 2 TS to include a temporary, one-time, 14-day AOT for the primary offsite power source to provide sufficient time for the replacement of the RSST C 5KV cables to transfer bus F during the Spring 2020 Unit 2 refueling outage. The temporary AOT will permit Unit 1 power operation to continue while RSST C is out of service to facilitate replacement of the RSST C 5KV cables.

• 4.1 Applicable Regulatory Requirements/Criteria The regulations in Appendix A to Title 10 of the Code of Federal Regulations (10 CFR)

Part 50 establish minimum principal design criteria for water-cooled nuclear power plants, while 10 CFR 50 Appendix 8 and the licensee quality assurance programs establish quality assurance requirements for the design, manufacture, construction, and operation Page 16 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 of structures, systems, and components. The current regulatory requirements of 10 CFR 50 Appendix A applicable to the proposed change GDC 5 (Sharing of Structures, Systems, and Components), GDC 17 (Electric Power Systems), and GDC 18 (Inspection and Testing of Electric Power System).

During the initial plant licensing of Surry Units 1 and 2, it was demonstrated that the design of the Surry electrical distribution system met the regulatory requirements in place at that time. The draft GDC published in 1967 included Criterion 4 (Sharing of Systems) and Criterion 39 (Emergency Power for Engineered Safeguards), which are pertinent to the proposed change. The GDC included in Appendix A to 10 CFR 50 did not become effective until May 21, 1971. The Construction Permits for SPS Units 1 and 2 were issued prior to May 21, 1971; consequently, Surry Units 1 and 2 were not subject to current GDC requirements (SECY-92-223, dated September 18, 1992). However, subsequent reviews of Surry considered the current GDC 5, GDC 17, and GDC 18 requirements.

GDC 5 - Sharing of Structures. Systems. and Components "Structures, systems, and components important to safety shall not be shared between nuclear power Units unless it can be shown that such sharing will not significantly impair their ability to perform their safety functions including, in the event of an accident in one Unit, an orderly shutdown and cooldown of the remaining Unit."

GDC 17 - Electric Power Systems "An onsite electric power system and an offsite electric power system shall be provided to permit functioning of structures, systems, and components important to safety. The safety function for each system (assuming the other system is not functioning) shall be to provide sufficient capacity and capability to ensure that (1) .specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded as a result of anticipated operational occurrences, and (2) the core is cooled and containment *integrity and other vital functions are maintained in the event of postulated accidents.

The onsite electric power sources, including the batteries, and the onsite electrical distribution system, shall have sufficient independence, redundancy, and testability to perform their safety functions, assuming a single failure.

Electric power from the transmission network to the onsite electric distribution system shall be supplied by two physically independent circuits (not necessarily on separate rights of way) designed and located so as to minimize to the extent practical the likelihood of their simultaneous failure under operating and postulated accident and environmental conditions. A switchyard common to both circuits is acceptable. Each of these circuits shall be designed to be available in sufficient time following a loss of all onsite alternating current power supplies and the other offsite electrical power .circuit, to ensure that specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded. One of these circuits shall be designed to be available within a few seconds following a loss of coolant accident to ensure that core Page 17 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 cooling, containment integrity, and other vital safety functions are maintained. Provisions shall be included to minimize the probability of losing electric power from any of the remaining supplies as a result of, or coincident with, the loss of power generated by the nuclear power Unit, the loss of power from the transmission network, or the loss of power from the onsite electrical power supplies."

GDC 18 - Inspection and Testing of Electric Power System "Electric power systems important to safety shall be designed to permit appropriate periodic inspection and testing of important areas and features, such as wiring, insulation, connections, and switchboards, to assess the continuity of the systems and the condition of their components. The systems shall be designed with a capability to test periodically (1) the operability and functional performance of the components of the systems, such as onsite power sources, relays, switches, and buses and (2) the operability of the systems as a whole and, under conditions as close to design as practical, the full operational sequence that brings the systems into operation, including operation of applicable portions of the protection system and the transfer of power among the nuclear power Unit, the offsite power system, and the onsite power system."

Additional references include:

• NRC Reg. Guide 1.93, "Availability of Electric Power Sources," dated December 1974

[Ref. 8.4]

• NRC Reg. Guide 1.155, "Station Blackout," dated August 1988 [Ref. 8.3]

• NUREG-0800, Branch Technical Position 8-8, "Onsite (Emergency Diesel Generators) and Offsite Power Sources Allowed Outage Time Extensions" [Ref. 8.2]

Analysis The temporary 14-day AOT allows the dependable alternate power source to supply transfer bus F instead of the normal primary offsite power source. There are no other changes regarding the onsite and offsite power supplies.

The regulatory position in Reg. Guide 1.93 when " ... available offsite ac power sources are one less than the LCO," is based on the following regulatory assumption:

This degradation level means that one of the required offsite ac sources is not available, and therefore, the offsite ac power system has no redundancy.

• However, full redundancy for Unit 1 continues to be. maintained because (a) one primary offsite power source is connected to the 230KV switchyard (emergency bus 1J via RSST A), and (b) one designated reliable offsite power supply is connected to the 500KV switchyard (emergency bus 1H via the Unit 2 backfeed), which confirms both its operability and continue6 availability. The functionality of the SRT 4 transformer to the RSST A circuit will be confirmed less than 30 days before establishing the AOT configuration.

Page 18 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 4.2 No Significant Hazards Consideration Pursuant to 10 CFR 50.90, Virginia Electric and Power Company (Dominion Energy Virginia) requests amendments to Surry Power Station (Surry) Units 1 and 2 Facility Operating License Numbers DPR-32 and DPR-37, respectively, in the form of a change to the Technical Specifications (TS). The proposed change adds a footnote to TS 3.16, "Emergency Power System," to allow a one-time extension of the Allowed Outage Time (AOT} in TS 3.16 Action B.2 from 7 days to 14 days. The requested temporary 14-day AOT is needed to replace the Reserve Station Service Transformer C (RSST C) 5KV cables to transfer bus F during the Surry Unit 2 Spring 2020 refueling outage. The existing RSST C 5KV cables are aging plant equipment and are reaching the end of their reliable service life. In addition, the existing cables are subject to premature shield failure due to long vertical cable routes, which can cause shield slippage over time and eventual insulation breakdown and failure. Such a failure would cause a loss of the offsite power source to the 1Hand 2J emergency buses and would require both units to enter a 7-day AOT. Replacement of the RSST C 5KV cables will assure continued dependable and safe generation of electrical power. The proposed temporary 14-day AOT is needed to allow sufficient time to replace the RSST C 5KV cables while permitting Unit 1 to maintain normal power operation. The temporary 14-day AOT also precludes the unnecessary transient of shutting down Unit 1 and the attendant risk.

In accordance with the criteria set forth in 10 CFR 50.92, Dominion Energy Virginia has performed an analysis of the proposed TS change and concluded that it does not represent a significant hazards consideration. The following discussion .is provided in support of this conclusion:

i. Does the proposed change involve a significant increase in the probability or consequences of an accident previously evaluated?

Response: No The proposed change adds a footnote to TS 3.16, "Emergency Power System," to allow a one-time extension of the AOT in TS 3.16 Action B.2 from 7 days to 14 days to facilitate the replacement of the RSST C 5KV cables to transfer bus F.

During the temporary 14-day AOT, the station emergency buses will continue to be fed from redundant, separate, reliable offsite sources that can support the emergency loads under worst-case conditions considering a single failure.

There are two (2) emergency buses for each unit: buses 1H and 1J (Unit 1), and buses 2H and 2J (Unit 2). While RSST C is out of service to facilitate replacement of the RSST C 5KV cables during the temporary 14- day AOT, buses 1J and 2H will continue to be energized from a designated primary offsite source, System (Switchyard)

Reserve Transformer (SRT) 4. Buses 1H and 2J will be energized from Main Step-up Transformer 2, which is the Unit 2 designated dependable alternate source.

Page 19 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 In both configurations transfer bus F is fed through two, in series, transformers.

• The normal configuration feeds transfer bus F from the 230KV switchyard via two (2) transformers (SRT 2 and RSST C) and two (2) breakers. The 230KV switchyard is connected to ten (10) offsite circuits.

• The temporary 14-day AOT configuration feeds transfer bus F from the 500KV switchyard via two (2) transformers (Main Step-up Transformer 2 and Station Service Transformer 2C) and three (3) breakers. The 500KV switchyard is connected to three offsite circuits.

A risk assessment has been performed for the temporary 14-day AOT configuration.

The assessment concluded that the probability of a loss of offsite power for the proposed configuration is very low. Thus, the proposed change does not significantly increase the probability of an accident previously evaluated because: (a) the emergency buses continue to be fed from redundant, separate, reliable offsite sources and (b) the effect of the proposed configuration on the probability of a loss of offsite power is very low.

There is no increase in the consequences of an accident because the emergency buses continue to be fed from redundant, separate, reliable offsite circuits and the onsite power sources (i.e., the Emergency Diesel Generators) are unaffected.

The consequences of both a Loss of Offsite Power (LOOP) and a Station Blackout (SBO) have been evaluated in the UFSAR. There is no change in the station responses to a LOOP or an SBO as a result of the extended AOT because RSST C is not included in designated equipment used in the LOOP and SBO coping_ strategies.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

ii. Do the proposed changes create the possibility of a new or different kind of accident from any accident previously evaluated?

Response: No The proposed configuration does not result in a change in the way the electrical distribution subsystems downstream of RSST C provide plant protection. During the temporary AOT (14 days total), the only change is to substitute the reliable Unit 2 designated dependable alternate source for a primary offsite power source for emergency buses 1H and 2J. Other sources of offsite and onsite power are unaffected, and other aspects of the offsite and onsite power supplies are unchanged and unaffected.

Page 20 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 There are no changes to the other RSSTs or to the supporting systems operating characteristics or conditions.

There is no change ilJ the station responses to a LOOP or an SBO because RSST C is not included in the designated equipment used in the LOOP and SBO coping strategies.

Therefore, the proposed change does not create- the possibility of a new or different kind of accident from any accident previously evaluated.

iii. Do the proposed changes involve a significant reduction in a margin of safety?

Response: No The proposed TS change does not affect the acceptance criteria for any analyzed event, nor is there a change to any safety limit. The proposed TS change does not affect any structures, systems or components or their capability to perform their intended functions. The proposed change does not alter the way safety limits, limiting safety system settings or limiting conditions for operation are determined. Neither the safety analyses nor the safety analysis acceptance criteria are affected by this change. The proposed change will not result in plant operation in a configuration outside the current design basis as the design basis includes use of the Unit 2 dependable alternate source. The proposed TS change allows use of the Unit 2 dependable alternate power source as the primary source for buses 1H and 2J for a period of up to 14 days. The margin of safety is maintained by maintaining the capability to supply emergency buses 1H and 2J with a redundant, separate, reliable offsite power source, and maintaining the onsite power sources in their design basis configuration. Therefore, the proposed change does not involve a significant reduction in margin of safety.

Based on the discussion above, Dominion Energy Virginia concludes that the proposed TS change presents no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and, accordingly, a determination of "no significant hazards consideration" is justified.

5.0 PRECEDENTS As noted in Section 1.0, to facilitate the replacement of the RSST C 5KV cables to transfer bus F, RSST C will be taken out of service. Thus, the electrical configuration of the plant for this modification is the same as it was for the RSST C replacement completed during the Unit 2 Fall 2018 refueling outage. The temporary 21-day AOT for the RSST C

. replacement was NRC approved by TS Amendments 293/293, which were . issued on October 5, 2018. [Ref. 8.5]

Page 21 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1

6.0 ENVIRONMENTAL CONSIDERATION

The proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9) as follows:

(i) The proposed change involves no significant hazards consideration.

As described in Section 4.2 above, the proposed change involves no significant hazards consideration.

(ii) There are no significant changes in the types or significant increase in the amounts of any effluents that may be released off-site.

The proposed change implements temporary TS requirements for the Unit 1 Emergency Power System and, as such, does not involve the installation of any new equipment or the modification of any equipment that may affect the types or amounts of effluents that may be released off-site. The proposed change will have no impact on normal plant releases and will not increase the predicted radiological consequences of accidents postulated in the UFSAR. There are no significant changes in the types or significant increase in the amounts of any effluents that may be released off-site.

(iii) There is no significant increase in individual or cumulative occupational radiation exposure.

The proposed change implements temporary TS requirements for the . Unit 1 Emergency Power System to support replacement of the RSST C 5KV cables to transfer bus F. The proposed TS change does not implement plant physical changes or result in plant operation in a configuration outside the plant safety analyses or design basis. Therefore, there is no significant increase in individual or cumulative occupational radiation exposure associated with the proposed change.

Based on the above, Dominion Energy Virginia concludes that, pursuant to 10 CFR 51.22(b ), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.

7 .0 CONCLUSION The proposed change adds a footnote to TS 3.16, "Emergency Power System" to allow a one-time extension of the Unit 1 AOT in TS 3.16 Action B.2 from 7 days to 14 days to replace the RSST C 5KV cables to transfer bus F. The new routing for the RSST C 5KV cables maintains adequate physical separation and independence. The design function of the Emergency Power System and the station's compliance with GDC 17 are not Page 22 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 affected by the proposed change. Additionally, the proposed change will not result in plant operation in a configuration outside the current design basis and does not affect the safety analyses.

Therefore, Dominion Energy Virginia concludes, based on the considerations discussed herein, that (1) there is reasonable assurance that the health and safety of the public will not be en~angered by operation in the proposed manner, (2) such activities will be

- conducted in compliance with-the _C0mmission~s-regulations,-and:-(3)-the issuance of-the amendmentwill not be inimical to the common defense and security or to the health and safety of the public.

8.0 REFERENCES

8.1 UFSAR Figure 8.3-1, "Electric Power Distribution" 8.2 NUREG-0800, Standard Review Plan, Branch Technical Position (BTP) 8-8, "Onsite (Emergency Diesel Generators) and Offsite Power Sources Allowed Outage Time Extensions" 8.3 NRG Reg. Guide 1.155, "Station Blackout," dated August 1988 8.4 NRG Reg. Guide 1.93, "Availability of Electric Power Sources", dated December 1974 8.5 Letter to Mr. Daniel G. Stoddard (Dominion Energy Vir-giniaNirginia Electric and Power Company) from James R. Hall (USNRC), dated October 5, 2018, "Surry Power Station, Units 1 and 2 - Issuance of Amendments Revising Technical Specifications 3.16, 'Emergency Power System,' for a Temporary 21-day Allowed Outage Time (EPID L-2017-LLA-0380)" (ADAMS Accession No. ML18261A099) 9.0 FIGURES 9.1 Existing Configuration 9.2 Temporary 14-day AOT Configuration 9.3 Surry Electric Power Distribution Page 23 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST :c 1

Cable Replacement LAR

! Attachment 1 CombuStion* COm~us'tion Gas Gas Church-

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~ S a f e t y Bus 2H

~ *

~SafetyStJS.lH j

~ Safety Bus 1J

~ ~

\..:_) - __ Safety Bus 2J Figure 9.1: Existing Configuration 1-Page 24 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1 Comb'ustion Combustion Gas Gas Church-Yadkin Turbines Turbines Chucl<.atuck Hopewell Winchester Hopewell SEPTA, Suffolk Chickahominy Turbine 1 Turbine 2 l~nd

• s & 6 3&4 L

~

~

23.0 ~V Switchyard '

~

~

500 kV Switchyard I

"ystem Reserv.e Transformer 4

+

,ystem Reserve Transformer 2

y;tem Reserve Transformer 1

Main Tran.sformet 2

I BUS 7 ~suss__/ I'\ BU Transformer SSTX 2C X

BUS D BUSE BUSF

~~

~ Safety Bus 1H

~ safety Bus2H

~ Safety Bus2J Figure 9.2: Temporary 14-day AOT Configuration Page 25 of 26

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 1

),l.l!,l!V I~ 1*I::7*

~

"tt:" DOT¥! 5TRUi:IUJl'.E~

Figure 9.3: Surry Electric Power Distribution Page 26 of 26

Serial No.19-424 Docket Nos. 50-280/281

• RSST C Cable Replacement LAR Attachment 1 Attachment 2 AAC (STATION BLACKOUT) DIESEL CORRECTIVE / PREVENTIVE MAINTENANCE PROCEDURES LIST Virginia Electric and Power Company (Dominion Energy Virginia)

Surry Station Units 1 and 2

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 2 AAC (Station Blackout) Diesel Corrective/Preventive Maintenance Procedures List As stated in Attachment 1, numerous AAC (station blackout) diesel corrective/preventive maintenance procedures exist and could be used to restore the functionality of the AAC diesel/system based upon the nature of the failure and the required repair. A list of these

.procedures is--provided below: -* -* * - **** - *-

• 0-DRP-SBO, Station Blackout Diesel Instrumentation Setpoints, Ranges and Tolerances

• O-ECM-0705-01, Station Blackout Diesel Maintenance

• O~ECM-0705-02, AAC Diesel Voltage Regulator Replacement

• O-ECM-0708-06, Field Adjustment of Station Blackout (SBO) Diesel Generator Governor Control System

• O-ECM-0708-08, SBO Diesel Automatic Generator Loading Control (AGLC) Governor*

Control Module Maintenance

• O-ECM-0708-09, Woodward 2301A Electronic Governor Control Module Maintenance

• O-ECM-0708-11, SBO Diesel Generator Load Pulse Unit (LPU) Governor Control /

Module Maintenance

• O-EPM-0107-04, SBO Battery Performance Test

• O-EPM-0109-05, Station Blackout Diesel Battery Periodic Checks

• O-EPM-0705-01, Station Blackout Diesel Preventive Maintenance.

• O-EPM-0705-02, Station Blackout Diesel Engine Speed Switch (ESS) Replacement -

Calibration - Functional Test

• O-EPM-1807-08, Circuit Breaker 05L 1 AA C Bus OL to Transfer Bus E Tie Breaker Re(ay Maintenance

• O-EPM-1807-09, Circuit Breaker 05L2 AAC Bus OL Feeder Breaker to OM Bus Relay Maintenance

• O-EPM-1807-10, Circuit Breaker 05L3 AAC Bus OL to Transfer Bus D Tie Breaker Relay Maintenance

• O-EPM-1807-11, AAC OL Bus Differential and Voltage Balance Relay Maintenance

• . O-EPM-1807-12, Circuit Breaker 05M1 AA C Feeder Breaker from Transformer OM1 Relay Maintenance

• O-EPM-1807-14, Circuit Breaker 05M3 AAC Feeder Breaker to Bus OL Relay Maintenance

• O-EPM-1807-15, Circuit Breaker 05M4 AAC Generator Output Breaker to Bus OM Relay Maintenance Page 1 of 2

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 2

• O-EPM-1807-16, AAC OM Bus Differential and Voltage Balance Relay Maintenance

• O-EPM-1807-17, AAC OM1 Bus Undervoltage Monitoring Relay Maintenance

• O-EPM-1807-18, AAC Generator Differential Relay Maintenance

• O-EPM-1807-19, AAC Generator Protective Relay Maintenance

• O-EPM-1807-20, AAC Generator Synchronizing Relay Maintenance

.-- O-IPM=AAC-O-CM-001, Station-8lc1ckout Diesel Modlcon--,~odernReboot

• O-IPM-AAC-PLC-001, Station Blackout Diesel Modicon PLC Monitoring

• O-IPM-AAC-PLC-002, Station Blackout Diesel GE Fanuc PLC Monitoring

• O-MCM-0750-04, Repair of Caterpillar Station Black-Out Diesel Injector

• O-MCM-0750-06, Repair of Station Black-Out Diesel Start Air Pressure Reduction Valve

• O-MPM-0221-03, Atlas Copco SBO Diesel Air Start Compressor Service and Inspection .

• O-MPM-0750-02, Caterpillar Station Black-Out Diesel Service and Inspection

• O-MCM-0750-07, Replacement and Testing of Woodward EGB-29P Governor Actuator Page 2 of 2

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 3 REGULATORY COMMITMENT

SUMMARY

Virginia Electric and Power Company (Dominion Energy Virginia)

Surry Station Units 1 and 2

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 3 REGULATORY COMMITMENT

SUMMARY

No. Commitment Due Date/Event 1 The temporary 14-day AOT will be used only once during During the time RSST C is the Spring 2020 Unit 2 refueling outage to complete out of service during the replacement of the RSST C 5KV cables to transfer bus F. Spring 2020 Unit 2 .

refueling outage 2 Weather conditions will be monitored, and preplanned During the time RSST C is maintenance will not be scheduled if severe weather out of service during the conditions are anticipated. Spring 2020 Unit 2 refueling outage 3 The system load dispatcher will be contacted once per During the time RSST C is day to ensure no significant grid perturbations (high grid out of service during the loading unable to withstand a single contingency of line or Spring 2020 Unit 2 generation outage) are expected during the temporary refueling outage 14-day AOT.

4 Component testing or maintenance of safety systems and During the time RSST C is important non-safety equipment in the offsite power out of service during the systems that can increase the likelihood of a plant Spring 2020 Unit 2 transient (unit trip) or LOOP will be avoided. In addition, refueling outage no discretionary switchyard maintenance will be performed.

5 TS required systems, subsystems, trains, components, During the time RSST C is and devices that depend on the remaining power sources out of service during the will be verified to be operable and positive measures will Spring 2020 Unit 2 be provided to preclude subsequent testing or refueling outage maintenance activities on these systems, subsystems, trains, components, and devices.

6

• Operation or maintenance of plant equipment when its During the time RSST C is redundant equipment or train is out of service will be out of service during the controlled in accordance with procedure OP-SU-601, Spring 2020 Unit 2 "Protected Equipment". The Unit 1 steam-driven Auxiliary refueling outage Feedwater Pump will be controlled as "Protected Equipment" during the temporary 14-day AOT.

7 The status of the AAC diesel generator, EDGs, RSST A During the time RSST C is and RSST B will be monitored once per shift. out of service during the Spring 2020 Unit 2 refueling outage Page 1 of 1

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 4 MARKED-UP TECHNICAL SPECIFICATIONS AND BASIS PAGES (Basis Changes are for NRC Information Only)

Virginia Electric and Power Company

• (Dominion Energy Virginia)

Surry Station Units 1 and 2

TS 3.16-3 10 05 18

2. If a primary source is not available, the unit may be operated for seven (7) days provided the dependable alternate source can be OPERABLE within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. If specification A-4 is not satisfied within seven (7) days, the unit shall be brought to COLD SHUTDOWN.(*) Y

3. One battery may be inoperable for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided the other battery and battery chargers remain OPERABLE with one battery charger carrying the DC load of the failed battery's supply system. If the battery is not returned to OPERABLE status within the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period, the reactor shall be placed in HOT SHUTDOWN. If the battery is not restored to OPERABLE status within an additional 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, the reactor shall be placed in COLD SHUTDOWN.

4. One buried fuel oil storage tank may be inoperable for 7 days for tank inspection and related repair, provided the following actions are taken:

a. prior to removing the tank from service, verify that 50,000 gallons of replacement fuel oil is available offsite and transportation is available to deliver that volume of fuel oil within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, and

b. prior to removing the tank from service and at least once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, verify that the remaining buried fuel oil storage tank contains ~ 17,500 gallons, and

c. prior to removing the tank from service and at least once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, verify that the above ground fuel oil storage tank contains ~ 50,000 gallons.

(*) To facilitate the repla ment of the Reserve Station Service Transformer C ~ :i-ftsseeffl:teti eaeli.ag during the foll 2018 Unit 2 refueling outage, the use of a temporary, one-tim -2+-day allowed outage time (AOT) is permitted for the unavailability of a primary so entry into and during the -day AOT, the following actions shall be take *

• Within 30 days prior t entering the temporary -2+-day AOT, f ctionality of the Alternate AC (AAC) System, (i .. , the supplemental 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

Amendment Nos. 293 aad 293

TS 3.16-7 10 05 18 TS action statement 3.16.B. l.a.2 provides an allowance to avoid unnecessary testing of an OPERABLE EDG(s). If it can be determined that the cause of an inoperable EDG does not exist on the OPERABLE EDG(s), operability testing does not have to be performed. If the cause of the inoperability exists on the other EDG(s), then the other EDG(s) would be declared inoperable upon discovery, and the applicable required action (s) would be entered. Once the failure is repaired, the common cause failure no longer exists and the operability testing requirement for the OPERABLE EDG(s) is satisfied. If the cause of the initial inoperable EDG cannot be confirmed not to exist on the remaining EDG(s) ,

performance of the operability test within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provides assurance of continued operability of those EDG(s).

In the event the inoperable EDG is restored to OPERABLE status prior to completing the operability testing requirement for the OPERABLE EDG(s), the corrective action program will continue to evaluate the common cause possibility, including the other unit's 1

24-hour constraint imposed by the action statement.

According to Generic Letter 84-15 (Ref. 6), 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is reasonab e to con irm t OPERABLE EDG(s) is not affected by t em as the inoperable EDG.

0 Reserve Station Service Transformer (RS C 1s he primary offsite power source lH and 2J Emergency Buses via transfer bus F. To facilitate the replacement of ~ -1'\'-t--

lifl:6 assaeiatea eaaliHg during the Unit 2 refueling outage, Technical Specification 3 .16.B .2 is modified by a footnote permitting the use of a temporary , one ii===:::::=:---,r+m~ U...day allowed outage time (AOT). T e U-day AOT will permit Unit 1 to continue days. Whil navailable , transfer bus F a le alternate sour e (i.e, backfeed through the Unit 2

+/-8 Station Service Tr nsformer 2C). The backfeed power sr n shall be verified.

2. During di day AOT, the function lity of the AAC System shal checked once per shift. If the AAC System beco s non-functional at any time during day AOT, it shall be restored to functi nal status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, or the unit shall be brought to HOT SHUTDOWN ithin the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and COLD SHUTDOWN to facilitate the replacement of the RSSTC 5KV Amendment Nos. 293 !Hla 293

TS 3.16-7a 10 05 18 The verification of functionality of the AAC System prior to entering the temporary

~ -day AOT will be based on the previous satisfactory quarterly test. The once per shift unctionality check will be performed during shiftly operator rounds.

In addition to verifying and checking functionality of the AAC System prior to and during the temporary U-day AOT, the following actions will also be taken:

Wea er conditions will be monitored and preplanned maintenance will not be s eduled if severe weather conditions are anticipated.

The system load dispatcher will be contacted once per day to ensure no significant grid perturbations (high grid loading unable to withstand a single contingency of line or generation outage) are expected durin th -day AOT.

Component testing or maintenance of safety systems and important non-safety equipment in the offsite power systems that can increase the likelihood of a plant tra ient (unit trip) or LOOP will be avoided. In addition, no discretionary maintenance will be performed.

• s, subsystems, trains, components, and devices that depend on the remaining powers rces will be verified to be operable and positive measures will be provided to preclude bsequent testing or maintenance activities on these

• Operation or maintenance of plant equipm t when its redundant equipment or train is out of service will be controlled in accordanc ith procedure OP-SU-601, "Protected Equipment." The Unit 1 steam-driven Au * *ary Feedwater Pump will be controlled as "Protected Equipment" during the temporar day AOT.

• The status of the AAC diesel generator, EDGsS, RSST/ A and RSST/ B will be monitored once per shift.

Amendment Nos. 293 ttfle 293

Serial No.19-424 Docket Nos. 50-280/281 RSST C Cable Replacement LAR Attachment 5 PROPOSED TECH NICAL SPECIFICATIONS AND BASIS PAGES (Basis Changes are for NRC Information Only)

Virginia Electric and Power Company (Dominion Energy Virginia)

Surry Station Units 1 and 2

TS 3.16-3

2. If a primary source is not available, the unit may be operated for seven (7) days provided the dependable alternate source can be OPERABLE within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. If specification A-4 is not satisfied within seven (7) days, the unit shall be brought to COLD SHUTDOWN.(*)

3. One battery may be inoperable for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provided the other battery and battery chargers remain OPERABLE with one battery charger carrying the DC load of the failed battery's supply system. If the battery is not returned to OPERABLE status within the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period, the reactor shall be placed in HOT SHUTDOWN. If the battery is not restored to OPERABLE status within an additional 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, the reactor shall be placed in COLD SHUTDOWN.

4. One buried fuel oil storage tank may be inoperable for 7 days for tank inspection and related repair, provided the following actions are taken:

a. prior to removing the tank from service, verify that 50,000 gallons of replacement fuel oil is available offsite and transportation is available to deliver that volume of fuel oil withi n 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, and

b. prior to removing the tank from service and at least once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, verify that the remaining buried fuel oil storage tank contains ~ 17,500 gallons, and

c. prior to removing the tank from service and at least once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, verify that the above ground fuel oil storage tank contains ~ 50,000 gallons.

(*) To facilitate the replacement of the Reserve Station Service Transformer C 5KV cables to transformer bus F during the Spring 2020 Unit 2 refueling outage, the use of a temporary, one-time, 14-day allowed outage time (AOT) is permitted for the unavailability of a primary source. Prior to entry into and during the 14-day AOT, the following actions shall be taken:

• Within 30 days prior to entering the temporary 14-day AOT, functionality of the Alternate AC (AAC) System, (i.e., the supplemental power source) shall be verified.

• During the 14-day AOT, the functionality of the AAC System shall be checked once per shift. If the AAC System becomes non-functional at any time during the 14-day AOT, it shall be restored to functional status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, or the unit shall be brought to HOT SHUTDOWN within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

Amendment Nos. and

TS 3.16-7 TS action statement 3.16.B. l .a.2 provides an allowance to avoid unnecessary testing of an OPERABLE EDG(s). If it can be determined that the cause of an inoperable EOG does not exist on the OPERABLE EDG(s), operability testing does not have to be performed. If the cause of the inoperability exists on the other EDG(s), then the other EDG(s) would be declared inoperable upon discovery, and the applicable required action(s) would be entered. Once the failure is repaired, the common cause failure no longer exists and the operability testing requirement for the OPERABLE EDG(s) is satisfied. If the cause of the initial inoperable EOG cannot be confirmed not to exist on the remaining EDG(s),

performance of the operability test within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> provides assurance of continued operability of those EDG(s).

In the event the inoperable EOG is restored to OPERABLE status prior to completing the operability testing requirement for the OPERABLE EDG(s), the corrective action program will continue to evaluate the common cause possibility, including the other unit's EOG or the shared EOG. This continued evaluation, however, is no longer under the 24-hour constraint imposed by the action statement.

According to Generic Letter 84-15 (Ref. 6), 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is reasonable to confirm that the OPERABLE EDG(s) is not affected by the same problem as the inoperable EOG.

Reserve Station Service Transformer (RSST) C is the primary offsite power source for the 1H and 2J Emergency Buses via transfer bus F. To facilitate the replacement of the RSST C SKY cables to transfer bus F during the Spring 2020 Unit 2 refueling outage, Technical Specification 3.16.B.2 is modifi ed by a footnote permitting the use of a temporary, one time, 14-day allowed outage time (AOT). The 14-day AOT will permit Unit 1 to continue to operate for 14 days. While RSST C is unavailable to facilitate the replacement of the RSST C 5KV cables, transfer bus F will be powered from the dependable alternate source (i.e, backfeed through the Unit 2 Main Step-up Transformer/Station Service Transformer 2C). The backfeed power supply will allow transfer bus F to perform its normal function while the RSST C 5KV cables are being replaced. Prior to entry into the 14-day AOT, the following actions shall be taken:

1. Within 30 days prior to entering the temporary 14-day AOT, functionality of the Alternate AC (AAC) System (i.e., the supplemental power source) shall be verified.

2. During the 14-day AOT, the functionality of the AAC Sy-stem shall be checked once per shift. If the AAC System becomes non-functional at any time during the 14-day AOT, it shall be restored to functional status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, or the unit shall be brought to HOT SHUTDOWN within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

Amendment Nos. and

TS 3.16-7a The verification of functionality of the AAC System prior to entering the temporary 14-day AOT will be based on the previous satisfactory quarterly test. The once per shift functionality check will be performed during shiftly operator rounds.

In addition to verifying and checking functionality of the AAC System prior to and during the temporary 14-day AOT, the following actions will also be taken:

• Weather conditions will be monitored and preplanned maintenance will not be scheduled if severe weather conditions are anticipated.

• The system load dispatcher will be contacted once per day to ensure no significant grid perturbations (high grid loading unable to withstand a single contingency ofline or generation outage) are expected during the temporary 14-day AOT.

• Component testing or maintenance of safety systems and important non-safety equipment in the offsite power systems that can increase the likelihood of a plant transient (unit trip) or LOOP will be avoided. In addition, no discretionary switchyard maintenance will be performed.

• TS required systems, subsystems, trains, components, and devices that depend on the remaining power sources will be verified to be operable and positive measures will be provided to preclude subsequent testing or maintenance activities on these systems, subsystems, trains, components, and devices.

• Operation or maintenance of plant equipment when its redundant equipment or train is out of service will be controlled in accordance with procedure OP-SU-601 ,

"Protected Equipment." The Unit 1 steam-driven Auxiliary Feedwater Pump will be controlled as "Protected Equipment" duri ng the temporary 14-day AOT.

• The status of the AAC diesel generator, EDGs, RSST A and RSST B will be monitored once per shift.

Amendment Nos. and