ML20058F966

Issuance of Amendment Nos. 297 and 297 to Revise Technical Specifications 3.16, Emergency Power System, to Allow a One Time 14-Day Allowed Outage Time for Replacement of 5-KV Cables Associated with Reserve Station

ML20058F966
Person / Time
Site:	Surry
Issue date:	03/16/2020
From:	Geoffrey Miller Plant Licensing Branch II
To:	Stoddard D Virginia Electric & Power Co (VEPCO)
Miller G
References
EPID L-2019-LLA-0244
Download: ML20058F966 (26)

Text

March 16, 2020 Mr. Daniel G. Stoddard Senior Vice President and Chief Nuclear Officer Innsbrook Technical Center 5000 Dominion Blvd.

Glen Allen, VA 23060-6711

SUBJECT:

SURRY POWER STATION, UNITS 1 AND 2, ISSUANCE OF AMENDMENTS NOS. 297 AND 297, TO REVISE TECHNICAL SPECIFICATIONS 3.16, EMERGENCY POWER SYSTEM, TO ALLOW A ONE-TIME 14-DAY ALLOWED OUTAGE TIME FOR REPLACEMENT OF 5-KV CABLES ASSOCIATED WITH RESERVE STATION SERVICE TRANSFORMER C (EPID NO. L-2019-LLA-0244)

Dear Mr. Stoddard,

The U.S. Nuclear Regulatory Commission has issued the enclosed Amendment No. 297 to Renewed Facility Operating License No. DPR-32 and Amendment No. 297 to Renewed Facility Operating License No. DPR-37 for the Surry Power Station (Surry), Units 1 and 2, respectively.

The amendments revise the Technical Specifications (TSs) in response to your application dated October 30, 2019 (Agencywide Documents Access and Management System (ADAMS)

Accession No. ML19309D199), as supplemented by letter dated January 31, 2020 (ADAMS Accession No. ML20034F053).

The amendments revise the Surry, Units 1 and 2, TS 3.16, Emergency Power System, to allow a one-time extension of the allowed outage time in TS 3.16 Action B.2 from 7 days to 14 days.

A copy of the related Safety Evaluation is also enclosed. The notice of issuance will be included in the Commissions biweekly Federal Register notice.

Sincerely,

/RA/

G. Edward Miller, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-280 and 50-281

Enclosures:

1. Amendment No. 297 to DPR-32

2. Amendment No. 297 to DPR-37

3. Safety Evaluation Cc: Listserv

VIRGINIA ELECTRIC AND POWER COMPANY DOCKET NO. 50-280 SURRY POWER STATION, UNIT NO. 1 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE

Amendment No. 297 Renewed License No. DPR-32

1. The Nuclear Regulatory Commission (the Commission) has found that:

A.

The application for amendment by Virginia Electric and Power Company (the licensee) dated October 30, 2019, as supplemented by a letter dated January 31, 2020, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in 10 CFR Chapter I; B.

The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.

There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D.

The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.

The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.

2. Accordingly, the license is amended by changes to the Technical Specification as indicated in the attachment to this license amendment, and paragraph 3.B of the Renewed Facility Operating License No. DPR-32 is hereby amended to read as follows:

B Technical Specifications The Technical Specifications Contained in Appendix A, as revised through Amendment No. 297 are hereby incorporated in the renewed license. The licensee shall operate the facility in accordance with the Technical Specifications.

3. The license amendment is effective as of its date of issuance and shall be implemented within 60 days of the date of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

Michael T. Markley, Chief Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to License No. DPR-32 And the Technical Specifications Date of Issuance: March 16, 2020

VIRGINIA ELECTRIC AND POWER COMPANY DOCKET NO. 50-281 SURRY POWER STATION, UNIT NO. 2 AMENDMENT TO RENEWED FACILITY OPERATING LICENSE

Amendment No. 297 Renewed License No. DPR-37

1. The Nuclear Regulatory Commission (the Commission) has found that:

A.

The application for amendment by Virginia Electric and Power Company (the licensee) dated October 30, 2019, as supplemented by a letter dated January 31, 2020, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commissions rules and regulations set forth in 10 CFR Chapter I; B.

The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C.

There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commissions regulations; D.

The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E.

The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commissions regulations and all applicable requirements have been satisfied.

2. Accordingly, the license is amended by changes to the Technical Specification as indicated in the attachment to this license amendment, and paragraph 3.B of the Renewed Facility Operating License No. DPR-37 is hereby amended to read as follows:

B Technical Specifications The Technical Specifications Contained in Appendix A, as revised through Amendment No. 297 are hereby incorporated in the renewed license. The licensee shall operate the facility in accordance with the Technical Specifications.

3. The license amendment is effective as of its date of issuance and shall be implemented within 60 days of the date of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION

/RA/

Michael T. Markley, Chief Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

Attachment:

Changes to License No. DPR-37 And the Technical Specifications Date of Issuance: March 16, 2020

ATTACHMENT TO SURRY POWER STATION, UNITS NOS. 1 AND 2 LICENSE AMENDMENT NO. 297 RENEWED FACILITY OPERATING LICENSE NO. DPR-32 DOCKET NO. 50-280 AND LICENSE AMENDMENT NO. 297 RENEWED FACILITY OPERATING LICENSE NO. DPR-37 DOCKET NO. 50-281 Replace the following pages of the Licenses and the Appendix A Technical Specifications (TSs) with the attached revised pages. The revised pages are identified by amendment number and contained marginal lines indicating the areas of change.

Remove Pages Insert Pages License No. DPR-32, page 3 License No. DPR-32, page 3 License No. DPR-37, page 3 License No. DPR-37, page 3 TS TS 3.16-3 3.16-3 3.16-7 3.16-7 3.16-7a 3.16-7a

3. This renewed license shall be deemed to contain and is subject to the conditions specified in the following Commission regulations: 10 CFR Part 20, Section 30.34 of 1 O CFR Part 30, Section 40.41 of 10 CFR Part 40, Sections 50.54 and 50.59 of 10 CFR Part 50, and Section 70.32 of 10 CFR Part 70; and is subject to all applicable provisions of the Act and the rules, regulations, and orders of the Commission now or

• hereafter in effect; and is subject to the additional conditions specified below:

A. Maximum Power Level The licensee is authorized to operate the facility at steady state reactor core power levels not in excess of 2587 megawatts (thermal).

B. Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 297 are hereby incorporated in the renewed license. The licensee shall operate the facility in accordance with the Technical Specifications.

C. Reports The licensee shall make certain reports in accordance with the requirements of the Technical Specifications.

D. Records The licensee shall keep facility operating records in accordance with the requirements of the Technical Specifications.

E. Deleted by Amendment 65 F. Deleted by Amendment 71 G. Deleted by Amendment 227 H. Deleted by Amendment 227 I.

Fire Protection Surry - Unit 1 The licensee shall implement and maintain in effect the provisions of the approved fire protection program as described in the Updated Final Safety Analysis Report and as approved in the SER dated September 19, 1979, (and Supplements dated May 29, 1980, October 9, 1980, December 18, 1980, February 13, 1981, December 4, 1981, April 27, 1982, November 18, 1982, January 17, 1984, February 25, 1988, and Renewed License No. DPR-32 Amendment No. 297 E. Pursuant to the Act and 10 CFR Parts 30 and 70, to possess, but not separate, such by product and special nuclear materials as may be produced by the operation of the facility.

3. This renewed license shall be deemed to contain and is subject to the conditions specified in the following Commission regulations: 10 CFR Part 20, Section 30.34 of 10 CFR Part 30, Section 40.41 of 10 CFR Part 40, Sections 50.54 and 50.59 of 10 CFR Part 50, and Section 70.32 of 10 CFR Part 70; and is subject to all applicable provisions of the Act and the rules, regulations, and orders of the Commission now or hereafter in effect; and is subject to the additional conditions specified below:

A Maximum Power Level The licensee is authorized to operate the facility at steady state reactor core power Levels not in excess of 2587 megawatts (thermal)

B. Technical Specifications The Technical Specifications contained in Appendix A, as revised through Amendment No. 297 are hereby incorporated in this renewed license. The licensee shall operate the facility in accordance with the Technical Specifications.

C. Reports The licensee shall make certain reports in accordance with the requirements of the Technical Specifications.

D. Records The licensee shall keep facility operating records in accordance with the Requirements of the Technical Specifications.

E. Deleted by Amendment 54 F. Deleted by Amendment 59 and Amendment 65 G. Deleted by Amendment 227 H. Deleted by Amendment 227 Surry - Unit 2 Renewed. License No. DPR-37 Amendment No. 297

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 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 :2:: 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 :2:: 50,000 gallons.

(*) To facilitate the replacement of the Reserve Station Service Transformer C 5 KV 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. 297 and 297

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 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 EDG 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 EDG.

Reserve Station Service Transformer (RSST) C is the primary offsite power source for the lH and 2J Emergency Buses via transfer bus F. To facilitate the replacement of the RSST C 5KV cables to transformer 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 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 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. 297 and 297

TS 3.I6-7a 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 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 off site 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.

Amendment Nos. 297 and 297

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION TO ALLOW A ONE-TIME 14-DAY ALLOWED OUTAGE FOR REPLACEMENT OF 5-KILOVOLT CABLES ASSOCIATED WITH RESERVE STATION SERVICE TRANSFORMER C FACILITY OPERATING LICENSE NOS. DPR-32 AND DPR-37 VIRGINIA ELECTRIC AND POWER COMPANY DOMINION ENERGY VIRGINIA SURRY POWER STATION, UNITS 1 AND 2 DOCKET NOS. 50-280 AND 50-281

1.0 INTRODUCTION

By letter dated October 30, 2019 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML19309D199, supplemented by letter dated January 31, 2020 (ADAMS Accession No. ML20034F053), Virginia Electric and Power Company (Dominion Energy Virginia, the licensee) submitted a license amendment request (LAR) to revise technical specifications (TS) for the Surry Power Station (Surry), Units 1 and 2.

This amendment revises 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 for replacement of the 5-kilovolt (kV) cables from Reserve Station Service Transformer C (RSST C) to Transfer Bus F during the Surry Unit 2 refueling outage (RFO) in spring 2020. The RSST C 5-kV cables provide distributed, reliable offsite power from RSST C to Transfer Bus F, which supplies the 1H and 2J emergency buses. The RSST C and associated cables to Transfer Bus F provide offsite power to both units. Therefore, the TS change request applies to both units.

In its LAR, the licensee stated, To facilitate the replacement of the RSST C 5 kV 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 U.S. Nuclear Regulatory Commission (NRC) in TS Amendments 293/293 dated October 5, 2018. The NRC staff noted that these amendments (ADAMS Accession No. ML18261A099) were meant both for replacement of RSST C and associated cabling. In its supplement dated January 31, 2020, the licensee provided the following clarification:

The RSST C cabling discussed in the current LAR is the same cabling that was previously approved for replacement during the Unit 2 fall 2018 RFO by Surry Units 1 and 2 TS Amendments 293/293. However, the cable was not able to be replaced as planned. The cable replacement design change was awarded to an engineering firm with the intent to use a specific insulated bus (tubular bus) product to eliminate a known failure mechanism, i.e., excessive mechanical forces on the cable shield. During the owner's review of the provided design change, it was identified that the proposed insulated bus design tolerances did not meet the Surry design specification requirements. Specifically, the proposed insulated bus was considered more robust but was unable to meet the existing GDC-17 reactance [design] requirement. Therefore, the cable could not be replaced as planned during the previously approved 21-day AOT for the Surry Unit 2 fall 2018 RFO, and an alternate design solution was necessary. An improved cable design has since been completed and the cable procured for installation. The cables are now larger to meet the GDC-17 reactance criterion and to account for cable deration and have a higher temperature rating than the existing cables. Consequently, the additional AOT extension requested by this LAR will provide sufficient time to perform the cable replacement work during the upcoming Unit 2 spring 2020 RFO.

The supplement dated January 31, 2020, provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the NRC staffs original proposed determination that the amendment involves no significant hazards consideration, as published in the Federal Register on February 11, 2020 (85 FR 7792).

2.0 REGULATORY EVALUATION

2.1 Description of the Surry Power Distribution System In its LAR, the licensee stated that each unit has two independent 4,160-volt (V) emergency buses and associated switchgear. Unit 1 has 4,160-V buses, 1H and 1J, and Unit 2 has 4,160-V buses, 2H and 2J. Each bus is sized to carry 100 percent of the emergency load.

The RSSTs (34.4 kV-4,160 V) supply the safety-related buses during all modes of operation (normal, startup, and shutdown). There are three RSSTs common to both units. Each RSST is sized to start up a single unit or shut down both units. Normally, RSST A supplies bus 1J (via transfer bus D), RSST B supplies bus 2H (via transfer bus E), and RSST C supplies buses 1H and 2J (via transfer bus F).

Upstream system (switchyard) reserve transformers (SRTs) supply the RSSTs. The SRTs are designated as the primary offsite power sources. There are three SRTs: SRT 1 (500 kV-36.5 kV) supplies RSST A or RSST B (or both); SRT 2 supplies RSST C (230 kV-36.5 kV); and SRT 4 (230 kV-36.5 kV) can supply RSST A or RSST B (or both), or RSST C.

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

The main generator normally supplies the station nonsafety-related 4,160-V power distribution buses through station service/unit auxiliary transformers. During startup, shutdown, or hot-standby conditions, the RSSTs supply these nonsafety-related 4,160-V buses through 4,160-V transfer buses.

Offsite power can also be made available to the emergency buses within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> by removing a unit from service, disconnecting its generator from the isolated phase bus, and backfeeding offsite power through the main stepup transformer and station service/unit auxiliary transformers and through 4,160-V transfer buses.

Onsite Emergency Power Sources According to Section 8.5 of Surrys updated final safety analysis report (UFSAR), the emergency power system sources consist of three emergency diesel generators (EDGs) for two units. The Unit 1 EDG and the Unit 2 EDG are dedicated to emergency buses 1H and 2H, respectively. Units 1 and 2 share a third EDG, which acts as a swing diesel. Upon receipt of a safety injection signal on a unit, the shared EDG automatically aligns to either emergency bus 1J (Unit 1) or 2J (Unit 2) as a backup power supply for the accident unit. The shared diesel is configured to preferentially load to the Unit 2 emergency bus on a loss of offsite power without a safety injection signal. The Unit 1 and Unit 2 EDGs also supply power for certain common or shared plant systems and components. Each EDG has a cumulative 2,000-hour rating of 2,750 kilowatts (kW).

Alternate Alternating Current System According to Section 8.4.6 of Surrys UFSAR, in response to Title 10 of the Code of Federal Regulations (10 CFR) 50.63, Loss of All Alternating Current Power, the alternate alternating current (AC) (AAC) system provides AC power to one emergency bus on each unit during a station blackout (SBO) event. The AAC system consists of a single 4,160-V AC diesel-driven generator with a continuous rating of 3,300 kW and a 2,000-hour rating of 3,640 kW. This generator can provide power to 4,160-V transfer buses D and E, which, in turn, can provide power to emergency buses 1J and 2H, respectively (one 4,160-V safety-related bus in each unit). The AAC diesel generator can provide power to the emergency buses within 10 minutes of confirmation that an SBO event has occurred. It is sized to carry the loads necessary to bring both units to a safe-shutdown condition and maintain that condition for a postulated 4-hour SBO event.

2.2 Current Technical Specification Requirements TS 3.16.A.4 requires two physically independent circuits from the offsite transmission network to energize the 4,160-V and 480-V emergency buses. One of these sources must be immediately available (i.e., primary source). The primary source must come from SRTs 1, 2, or 4 and then through an RSST. The other source must be 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 alternate source can be made available in 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> by removing a unit from service, disconnecting its generator from the isolated phase bus, and feeding offsite power through the main stepup transformer and station service/unit auxiliary transformers and through the 4,160-V transfer buses.

According to TS 3.16.B.1.b.2, if the primary source is not available, the unit may be operated for 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 TS 3.16.A.4 is not satisfied within 7 days, the unit shall be brought to cold shutdown.

The primary source (offsite power) through RSST A serves emergency bus 1J of Unit 1; the primary source (offsite power) through RSST B serves emergency bus 2H of Unit 2; and the primary source (offsite power) through RSST C serves one emergency bus in each unit (i.e., 1H of Unit 1, and 2J of Unit 2).

2.3 Reason for the Proposed Change In its LAR, the licensee stated that the existing RSST C 5-kV cables (to transfer bus F) are aging 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 (approximately 80 feet vertical), 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 1H and 2J emergency buses and would require both units to enter a 7-day AOT.

The licensee also stated that the 5-kV cable replacement activities will 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 before the spring 2020 Unit 2 refueling outage. Cable termination/tie-in, as well as Tan Delta cable testing, will be performed during the outage. Currently, the RSST C 5-kV cables are routed up the side and on to the roof of the turbine building and into the Unit 1 normal switchgear room. The new routing for the RSST C 5-kV cables will be through the Unit 2 turbine building and into the Unit 1 normal switchgear room. The new routing for the RSST C 5-kV cables to transfer bus F will keep adequate physical separation and independence (from other cables), maintaining compliance with General Design Criterion (GDC)-17, Electric Power Systems, of Appendix A, General Design Criteria for Nuclear Power Plants, to 10 CFR Part 50, Domestic Licensing of Production and Utilization Facilities.

The proposed temporary 14-day AOT will allow adequate time to replace the RSST C 5-kV cables while permitting Unit 1 to maintain normal power operation and avoid an unnecessary transient of shutting down the reactor. In its LAR, Attachment 1, page 14, the licensee provided an activity schedule for replacement of the RSST C 5-kV cables. Based on this activity schedule, 14 days will be adequate time to complete the replacement of cables, including a reasonable margin.

2.4 Proposed Technical Specification Change The proposed change revises TS 3.16.B.2 to add a one-time extension of a primary source AOT from 7 days to 14 days, if the requirement for TS 3.16.A.4 (which specifies both primary source and dependable alternate source, as described in Section 2.2 of this safety evaluation) is not met.

The applicant proposed the following change to TS 3.16.B.2, indicated in BOLD:

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 A-4 is not satisfied within seven (7) days, the unit shall be brought to COLD SHUTDOWN. (*)

(*)

To facilitate the replacement of the Reserve Station Service Transformer C 5 KV 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 />.

2.5 Applicable Regulatory Requirements and Guidance The licensee received its construction permits for both SPS units in 1968. SPS Unit No. 1 was licensed for operation in December 1972 and SPS Unit No. 2 was licensed for operation in May 1973. During the initial plant licensing of SPS, Unit Nos. 1 and 2, design of the SPS electrical distribution system met the regulatory requirements in place at that time. The plants design approval for the construction phase was based on the proposed general design criteria (GDC) published by the Atomic Energy Commission (AEC) for public comment in the Federal Register (32 FR 10213) on July 11, 1967 (the draft GDC). The draft GDC included Criterion 4 (Sharing of Systems) and Criterion 39 (Emergency Power for Engineered Safety Features), which are applicable to the proposed change. On February 20, 1971, the AEC published in the Federal Register (36 FR 3255) a final rule that added Appendix A to 10 CFR Part 50, General Design Criteria for Nuclear Power Plants (the final GDC). Differences between the draft GDC and final GDC included a consolidation from 70 to 64 criteria. As discussed in the NRC Staff Requirements Memorandum for SECY 92 223, Resolution of Deviations Identified During the Systematic Evaluation Program, dated September 18, 1992 (ADAMS Accession No. ML003763736), the Commission decided not to apply the final GDC to plants with construction permits issued prior to May 21, 1971. However, per SPS Updated Final Safety Analysis Report (UFSAR) Chapter 8, Electrical Systems, the SPS electrical distribution system was technically evaluated and determined to be in compliance with final GDC Criterion 17, Electric Power System.

The NRC staff applied the following regulatory requirements and guidance documents for review of the LAR.

SPS UFSAR Chapter 8, Electrical Systems, discusses the electrical power distribution system. The electrical systems are designed to supply electrical power to all essential unit equipment during normal operation and under accident conditions. The electrical power distribution system for the Surry Power Station provides duplicate systems for emergency components. Each system is continuously energized from the external system grid or from onsite diesel generators. The system is designed such that should a loss of offsite power (LOOP) occur, the onsite diesel generators will power the emergency power system.

SPS UFSAR Section 1.4.4, Sharing of Systems, discusses the sharing of systems and components. The reactor facilities do not share systems or components unless it is shown that safety is not impaired by sharing.

SPS UFSAR Section 1.4.39, Emergency Power for Engineered Safeguards, discusses the alternative power systems. The alternative power systems are provided and designed with adequate independence, redundancy, capacity, and testability to permit the functioning required of the engineered safeguards. As a minimum, the onsite power system and offsite power system each, independently provide this capacity, assuming the failure of a single active component in each power system.

Section 10 CFR 50.36, Technical specifications, requires, in part, that the TSs and a summary statement of the bases for such specifications shall be included by applicants for a license authorizing operation of a production or utilization facility. Specifically, 10 CFR 50.36(c) requires that TSs include items in five specific categories related to station operation. These categories are (1) safety limits, limiting safety system settings, and limiting control settings, (2) limiting conditions for operation (LCOs), (3) surveillance requirements, (4) design features, and (5) administrative controls. The proposed change to the SPS TS relates to the LCO category.

Section 10 CFR 50.36(c)(2), Limiting conditions for operation, provides the requirements for the establishment of TS limiting conditions for operation. Specifically, 10 CFR 50.36(c)(2)(i) provides that limiting conditions for operation are the lowest functional capability or performance levels of equipment required for safe operation of the facility. When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the technical specifications until the condition can be met.

Section 10 CFR 50.63, Loss of all alternating current power, requires, in part, that a nuclear power plant shall be able to withstand for a specified duration and recover from a complete loss of offsite and onsite alternating current (AC) sources (i.e., a station blackout (SBO)).

Section 10 CFR 50.65, Requirements for monitoring the effectiveness of maintenance at nuclear power plants, requires, in part, that the licensee shall monitor the performance or conditions of structures, systems or components in a manner sufficient to provide reasonable assurance that these structures systems and components are capable of fulfilling their intended functions.

The NRC staff also reviewed the LAR based on the following regulatory guidance documents:

NUREG-0800, BTP 8-8, February 2012 (ADAMS Accession No. ML113640138),

provides guidance to the NRC staff in reviewing LARs for licensees proposing a one-time or permanent TS change to extend an Emergency Diesel Generator (EDG)

AOT beyond 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The BTP 8-8 emphasizes that more defense-in-depth is needed for SBO scenarios that are more likely to occur as compared to the likely occurrence of the large and medium size loss-of-coolant accident scenarios (which require a fast start EDG).

NUREG-0800, Standard Review Plan, Section 19.2, Review of Risk Information Used to Support Permanent Plant-Specific Changes to the Licensing Basis: General Guidance, June 2007 (ADAMS Accession No. ML071700658) provides guidance to the NRC staff on how information from a probabilistic risk analysis (PRA) can be combined with other pertinent information in the process of making a regulatory decision. Specifically, Appendix D defines those conditions or situations that constitute special circumstances where additional risk information may be required.

Regulatory Guide (RG) 1.93, Availability of Electric Power Sources, March 2012 (ADAMS Accession No. ML090550661), provides guidance with respect to operating restrictions on completion times (CTs) if the number of available AC sources is less than that required by the TS LCO. In particular, this guide recommends a maximum CT of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for an inoperable onsite or offsite AC source where the available onsite or offsite power source is one less than the LCO.

RG 1.155, Station Blackout, August 1988 (ADAMS Accession No. ML003740034),

provides guidance for complying with 10 CFR 50.63 that requires nuclear power plants to be capable of coping with an SBO event for a specified duration.

RG 1.177, An Approach for Plant-Specific, Risk-Informed Decision making: Technical Specifications, May 2011 (ADAMS Accession No. ML100910008), describes an acceptable risk-informed approach for assessing proposed changes to TS AOTs.

The SPS TSs are custom for the plant and were derived at the time of initial licensing. The NRC staff also reviewed the LAR based on the regulatory guidance in NUREG-0800, Standard Review Plan for the Review of Safety Analysis Reports for Nuclear Power Plants: LWR Edition, Branch Technical Position (BTP) 8-8, Onsite (Emergency Diesel Generators) and Offsite Power Sources Allowed Outage Time Extensions, issued February 2012 (ADAMS Accession No. ML113640138), provides guidance to the NRC staff in reviewing LARs relating to AOT extension beyond 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. BTP 8-8 emphasizes that sufficient power sources should be available, considering a power source under maintenance and another single failure, to avoid a potential extended SBO event during the period of an extended AOT and to enable safe shutdown (cold shutdown) of the unit if the power source under maintenance cannot be restored in a timely manner. BTP 8-8 also recommends additional compensatory measures during an extended AOT.

3.0 TECHNICAL EVALUATION

The NRC staff has evaluated the proposed change, considering both traditional engineering and risk-insight, to determine whether, during the operation of Unit 1 and the 14-day AOT of one primary source/offsite circuit (RSST C unavailable due to the associated replacement of 4,160-V cables to transfer bus F), the risk would remain low; therefore, continued operation of Unit 1 during the extended AOT will not endanger public health and safety.

3.1 Defense-in-depth for Onsite and Offsite Power Sources during the Propose AOT 3.1.1 Accident Analysis Requirement In its LAR, Attachment 1, page 6, the licensee stated the following:

While RSST C is unavailable to facilitate the replacement of the RSST C 5 KV 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 5 KV cables are being replaced.

In its LAR, Attachment 1, page 9, the licensee stated that, during the temporary one-time 14-day AOT, the configuration and operating restrictions will be 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 [station service/unit auxiliary transformer feeding bus 2C; backfeed except during a short period of disconnecting the old 5 kV cables from RSSC T and connecting the new cables to bus F] (AOT configuration) with the following loads:

Bus 1H [safety-related]: normal operating load.

Bus 2J [safety-related]: normal outage load plus Residual Heat Removal (RHR) pump.

Bus 1C [non-safety-related]: will transfer to bus F if unit trips.

Bus 2C [non-safety-related]: Feedwater pump, Condensate, Bearing Cooling pump, 480 V lightingon; Reactor Coolant Pump, High Pressure Heater Drain, Low Pressure Heater Drain off.

In the supplement dated January 30, 2020, the licensee provided the following clarification:

The auto-start inhibit or blocking function described in the Surry UFSAR will function as intended, i.e., there are no new operating restrictions being imposed on this function. The Two Unit Load Shed Circuit is conservatively defeated during the 14-day AOT to avoid any inadvertent actuation of the circuitry while performing cabling installation at the transformer and the F transfer bus. This action is appropriate because the logic circuit for load shed is partially made-up when the shutdown unit is on the dependable alternate source (backfeed), which will be the case when the cable replacement is performed. With the refueling unit on backfeed, the refueling unit having reduced load, and RSST C out of service, there is no need for the load shed.

Based on the above, the NRC staff finds that at least one 4,160-V safety-related bus in each unit (Bus 1J, and Bus 2H) will remain powered by normal, primary offsite power to meet any accident requirements during the 14-day AOT. Other safety-related buses (1H and 2J) will also remain available while in backfeed mode. Also, all three EDGs would remain available to provide power to all safety-related buses. Therefore, the NRC staff finds that adequate power sources would remain available to meet any accident analysis requirements during the 14-day requested AOT.

3.1.2 Extended Station Blackout Event The BTP 8-8 emphasizes that sufficient power sources should be available, considering a power source under maintenance and another single failure, to avoid a potential extended SBO event during the period of an extended AOT and to enable safe shutdown (i.e., Cold Shutdown) of the unit if the power source under maintenance cannot be restored in a timely manner. The AAC source (i.e., the SBO diesel) to power one of the safety-related buses in each unit would remain available to meet any extended SBO event in any unit. In accordance with the proposed TS change, before 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 />.

As described in Section 2.1 of this safety evaluation, the AAC source is a diesel-driven generator with a continuous rating of 3,300 kW (rating higher than that of EDGs), which can provide power to safety-related 4,160-V buses 1J and 2H (i.e., power to one division of safety-related buses in each unit). Therefore, the NRC staff finds that adequate power sources would remain available to meet an extended SBO event, during the 14 days of requested AOT and would, therefore, meet the intent of BTP 8-8.

3.1.3 Additional Licensee Actions In its LAR, Attachment 1, pages 6 and 7, the licensee stated that, in addition to verifying and checking functionality of the AAC system before and during 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 nonsafety equipment in the offsite power systems that can increase the likelihood of a plant transient (unit trip) or LOOP [loss of offsite power] 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.

The NRC staff finds that the above actions will add to the defense-in-depth and the risk management of the plant. The compensatory measures also meet the intent of BTP 8-8 and are, therefore, acceptable.

3.1.4 Safety Margins Since the plant would be able to mitigate design basis accidents and remain capable of safe shutdown during the extended AOT, the NRC staff finds that there are sufficient safety margins and is, therefore, acceptable.

3.1.5 Traditional Engineering Conclusion In accordance with the discussion provided in Sections 3.1.1, 3.1.2, 3.1.3, and 3.1.4 of this safety evaluation, the NRC staff finds the proposed TS change maintains defense-in-depth and sufficient safety margin and is, therefore, acceptable.

3.2 Risk Insights Evaluation In its LAR, the licensee stated:

During the 14-day temporary AOT, the increase in risk will be assessed and managed in accordance with the requirements of 10 CFR 50.65(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.

The licensee further stated that the proposed TS change is a one-time, extension of the Allowed Outage Time (AOT) in TS 3.16 Action B.2 from 7 days to 14 days. Consistent with BTP 8-8, the licensee provided deterministic input with risk insights. Because the requested changes are consistent with the currently approved NRC staff position, this LAR is not a risk-informed LAR and a risk evaluation was not submitted by the licensee for the purpose of making a regulatory decision. The NRC staff determined that special circumstances did not exist. Such circumstances, as discussed in NUREG-0800, Section 19.2, Review of Risk Information Used to Support Permanent Plant-Specific Changes to the Licensing Basis; General Guidance, issued June 2007, would have required the inclusion of additional risk information.

Based on the above, the NRC did not review the PRA models used by the licensee to derive the submitted risk insights. The NRC staff performed an independent risk analysis using SAPHIRE Version 8.2.1.0 and the plant-specific NRC Standardized Plant Analysis Risk (SPAR) model.

The staff configured the plant-specific SPAR model to assess the risk impact contribution from internal events.

In its review of the risk insights provided by the licensee in Section 3.4 of the LAR and the insights from the plant-specific NRC SPAR model, the NRC staff determined that both support the traditional engineering analysis conclusions associated with the licensees proposed actions.

The available risk insights support the engineering conclusions that the proposed change maintains defense-in-depth with sufficient safety margins.

The NRC staff concludes that the licensees plan for compliance with 10 CFR 50.65(a)(4) ensures that the risk impact of a 14-day AOT during replacement of RSST-C and associated cabling is appropriately assessed and managed for the one-time TS change requested.

4.0 TECHNICAL CONCLUSION Based on the above, the NRC staff finds the proposed TS change will have a minimal impact on the continued safe operation and shutdown capability of Unit 1 during the proposed extended AOT of 14 days, and is, therefore, acceptable. The continued operation of Unit 1 will not endanger public health and safety. The licensee will also continue to meet the regulatory requirements in 10 CFR Sections 50.36(c)(2), 50.63 and 50.65, and the intent of 10 CFR 50 Appendix A, GDC 17, as provided in SPS UFSAR Chapter 8.

5.0 FINAL NO SIGNIFICANT HAZARDS CONSIDERATION

The NRCs regulation in 10 CFR 50.92(c) states that the NRC may make a final determination, under the procedures in 10 CFR 50.91, that a license amendment involves no significant hazards consideration if operation of the facility, in accordance with the amendment, would not:

(1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety.

An evaluation of the issue of no significant hazards consideration is presented below:

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 Stepup Transformer 2, which is the Unit 2 designated dependable alternate source.

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.

There are no changes to the other RSSTs or to the supporting systems operating characteristics or conditions.

There is no change in 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 above, the NRC staff concludes that the three standards of 10 CFR 50.92(c) are satisfied. Therefore, the NRC staff has made a final determination that no significant hazards consideration is involved for the proposed amendment and that the amendment should be issued as allowed by the criteria contained in 10 CFR 50.91.

6.0 STATE CONSULTATION

In accordance with the Commissions regulations, the NRC notified an official from the Virginia Division of Radiological Health of the proposed issuance of the amendment. On February 20, 2020, the State official confirmed that the Commonwealth of Virginia had no comments.

7.0 ENVIRONMENTAL CONSIDERATION

The amendment changes a requirement with respect to the installation or use of a facility component located within the restricted area, as defined in 10 CFR Part 20, Standards for Protection Against Radiation, and changes surveillance requirements. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released off site, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission previously issued a proposed finding that the amendments involve no significant hazards consideration, published in the Federal Register on February 11, 2020 (85 FR 7792),

and the agency has received no public comments on this finding. Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Under 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.

8.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, that (1) there is reasonable assurance that operation in the proposed manner will not endanger public health and safety, (2) there is reasonable assurance that such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of these amendments will not be inimical to the common defense and security or to public health and safety. Therefore, on the basis of the above review and justification, the NRC staff concludes that the request proposed in Surrys submittal dated October 30, 2019, is acceptable.

Principal Contributors:

Vijay Goel Adrienne Brown

ML20058F966

• Via Memorandum, **Via e-mail OFFICE NRR/DORL/ LPL2-1/PM NRR/DORL/LPL2-1/LA NRR/DRA/APLA/BC*

NAME VThomas KGoldstein RPascarelli DATE 02/27/2020 03/04/2020 02/14/2020 OFFICE NRR/DEX/EEOB/BC*

OGC**

NRR/DORL/LPL2-1/BC NAME BTitus KGamin MMarkley DATE 02/14/2020 03/06/2020 03/16/2020 OFFICE NRR/DORL/LPL2-1/PM NAME GEMiller DATE 03/16/2020