ML20351A331

(Vcsns), Unit 1 - Technical Specificatio Bases Revisions Updated Through November 2020

ML20351A331
Person / Time
Site:	Summer
Issue date:	12/15/2020
From:	Haselden R Dominion Energy South Carolina
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
20-395
Download: ML20351A331 (10)

Text

V. C. Summ er Nuclear Stat ion Bradha m Blvd & Hwy 215, Jen kinsvil le, SC 29065 M ail ing Addre ss:

5j; Dominion

iii" Energy P.O. Box 88 , Jenki n svill e, SC 29065 Dom ini on Energy.co m December 15, 2020 Attn

Document Control Desk Serial No.20-395 U. S. Nuclear Regulatory Commission VCS-LIC/BAB RO Washington, DC 20555-0001 Docket No. 50-395 License No. NPF-12 DOMINION ENERGY SOUTH CAROLINA (DESC)

VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) UNIT 1 TECHNICAL SPECIFICATION BASES REVISIONS UPDATED THROUGH NOVEMBER 2020 In accordance with Virgil C. Summer Nuclear Station (VCSNS) Unit 1 Technical Specifications (TS) 6.8.4.i.4, Dominion Energy South Carolina (DESC) , acting for itself and as agent for South Carolina Public Service Authority, submits revisions to the TS Bases.

This update includes changes to the TS Bases since the previous submittal in November 2019.

The enclosed changes revised by Bases Revision Notices (BRN)18-009, BRN 19-001 , BRN 19-004, and BRN 20-001 were implemented under the provision of 10 CFR 50.59. Changes are annotated by vertical revision bars and the BRN number at the bottom of the affected TS -Bases page.

Should you have any questions, please call Michael S. Moore at (803) 345-4752.

Robin R. Haselden General Manager, Organization Effectiveness V.C . Summer Nuclear Station Commitments contained in this letter: None : Summary of TS Bases Changes Through November 2020 : Technical Specification Bases Revisions Updated Through November 2020 cc: G. J. Lindamood - Santee Cooper L. Dudes - NRC Region II V. Thomas - NRC Project Manager NRC Resident Inspector

Serial No.20-395 Docket No. 50-395 Enclosure 1 Summary of TS Bases Revision Notices Through November 2020 Virgil C. Summer Nuclear Station (VCSNS) Unit 1 Dominion Energy South Carolina, Inc. (DESC)

Serial No.20-395 Docket No. 50-395 Enclosure 1 - Summary of TS Bases Changes: Page 1 of 2

SUMMARY

OF BASES CHANGES BRN 18-009 Description of Change: This revision removes Technical Specification Relocation/Interpretation (TSR) 1025 and 1026 from Technical Specifications (TS) and adds the amplifying information contained in the TSRs to TS Bases (3/4. 7 PLANT SYSTEMS).

Reason and Basis for Change: A Change Management Plan (CMP) CR-10-00870 was approved on December 11, 2014, with the goal of eliminating regulatory interpretations in the form of TSRs from TS. Action 18 in CR-10-00870 specifies the removal of TSRs 1025 and 1026 from TS.

BRN 19-001 Description of Change: This change consists of a revision of TS Bases Section 2.2 to update the Reactor Trip System Interlocks description for P-6 and P-10 to reflect the current plant operating characteristics.

Reason and Basis for Change: During power ascension, Source and Intermediate Range (SR, IR) reactor trips are blocked, but remain powered. The language in the current TS Bases reflects practices from the previous Westinghouse Boron Trifluoride proportional counters and needs to be updated to reflect operations using the current Gamma Metrics fission chambers. The original SR and IR detectors were replaced with post-accident qualified detectors (in accordance with RG 1.97) during the third refueling outage.

BRN 19-004 Description of Change: Revises the TS Bases for Section 3.4.6.1 of Tech Specs per CR-19-01287, specifically application of the "or" statements in TS 3.4.6.1 Actions band c with footnote (1 ).

Reason and Basis for Change: CR-19-01287 documents a condition which resulted in a NRC violation for misapplication of the "or statement in TS 3.4.6.1 Action c and footnote (1 ). The correct application of the "or" statement and footnote in these two actions are now described in TS Bases to provide better guidance on proper application of these statements.

Serial No.20-395 Docket No. 50-395 Enclosure 1 - Summary of TS Bases Changes: Page 2 of 2 BRN 20-001 Description of Change: Revises Surveillance Requirement 4.0.1 TS Bases to state that surveillances may be performed by means of any series of sequential, overlapping, or total steps. This change is similar to that of TSTF-434, "Clarifying SR 3.0.1 Bases to state that the Surveillance can be performed in steps," which was approved by the NRC via letter dated October 10, 2002 [ML022830194]. In this acceptance letter, the NRC states the following: "Surveillances are performed by means of any series of sequential, overlapping or total steps as long as the entire surveillance is performed as specified in the Technical Specifications. Performing the Surveillances in this manner reflects the industry practice and provides for the avoidance of unnecessary actuation of equipment that should not be run during power operation, improvement in scheduling and resources management and reduction of risk by scheduling test when the equipment is out of service."

Reason and Basis for Change: Surveillances are routinely performed in overlapping or sequential pieces for reasons such as avoiding the actuation of equipment which should not be run during power operation, improving scheduling and resource management, and reducing plant risk by scheduling when equipment is out of service. Additionally, benchmarking has identified a surveillance test philosophy that has the potential to remove some Engineered Safety Feature Actuation System Tests from critical path resulting in reduced outage time.

Serial No.20-395 Docket No. 50-395 Enclosure 2 Technical Specification Bases Revisions Updated Through November 2020 Virgil C. Summer Nuclear Station (VCSNS) Unit 1 Dominion Energy South Carolina, Inc. (DESC)

Serial No.20-395 Docket No. 50-395 Enclosure 2 - Technical Specification Bases Revisions: Page 1 of 5 TECHNICAL SPECIFICATION BASES REVISIONS UPDATED THROUGH NOVEMBER 2020 Revision Notice # Paaes Affected 18-009 B 3/4 7-2 19-001 B 2-8 19-004 B 3/4 4-4b 20-001 B 3/4 0-2

PLANT SYSTEMS BASES 3/4.7.1.2 EMERGENCY FEEDWATER SYSTEM The OPERABILITY of the emergency feedwater system ensures that the Reactor Coolant System can be cooled down to less than 350°F from normal operating conditions in the event of a total loss of off-site power.

Any two emergency feedwater pumps combined are capable of delivering a total feedwater flow of 380 gpm at a pressure of 1211 psig to the entrance of two out of three intact steam generators following a Main Feedwater Line Break event, while passively limiting the flow to the faulted steam generator. Automatic isolation of the faulted steam generator is not necessary to achieve this flow to the intact steam generators. The 380 gpm to the intact steam generators is sufficient to prevent over pressurization of the RCS and also to prevent the water in RCS hot leg from reaching a saturated condition. This capacity is sufficient to ensure that adequate feedwater flow is available to remove decay heat and reduce the Reactor Coolant System temperature to less than 350°F at which point the Residual Heat Removal System may be placed into operation.

Also, each Emergency Feedwater (EFW) pump is capable of supplying 400 gpm to all 3 steam generators while the steam generators are pressurized to 1211 psig. This capacity is sufficient to ensure that the pressurizer does not overfill during a loss of normal feedwater event. The minimum required pump head for the TD and MD pumps are controlled in accordance with the lnservice Testing Program as required by Specification 4.0.5. These minimum pump performance requirements ensure the minimum required EF flows are achieved, as described above.

The Turbine Driven Emergency Feedwater Pump (TDEFP) can be considered operable with XVT-2813 shut as long as the condensate level drain pot high level alarm is functional and below the high level alarm. With XVT-2813 shut, the drain pot should be blown down at least once per hour an otherwise as necessary to maintain the condensate level below the high level alarm.

3/4.7.1.3 CONDENSATE STORAGE TANK The OPERABILITY of the condensate storage tank with the minimum water volume ensures that sufficient water is available to maintain the RCS at HOT STANDBY conditions for 11 hours1.273148e-4 days <br />0.00306 hours <br />1.818783e-5 weeks <br />4.1855e-6 months <br /> with steam discharge to the atmosphere concurrent with total loss of offsite power.

The contained water volume limit includes an allowance for water not usable because of tank discharge line location or other physical characteristics.

3/4.7.1.4 ACTIVITY The limitations on secondary system specific activity ensure that the resultant offsite radiation dose will be limited to a small fraction of 10 CFR Part 50.67 limits in the event of a steam line rupture. This dose also includes the effects of a coincident 1.0 GPM primary to secondary tube leak in the steam generator of the affected steam line. These values are consistent with the assumptions used in the accident analyses.

SUMMER - UNIT 1 B 3/4 7-2 Amendment No. 4Q.9, Corrected by Letter Dated 10/4/93,

~ . BRN 11 001, BRN 17 002, BRN 18-009

LIMITING SAFETY SYSTEM SETTINGS BASES Reactor Trip System Interlocks The Reactor Trip System Interlocks perform the following functions:

P-6 On increasing power P-6 allows the manual block of the Source Range reactor trip. On decreasing power, Source Range level trips are automatically reactivated.

P-7 On increasing power P-7 automatically enables reactor trips on low flow in more than one primary coolant loop, more than one reactor coolant pump breaker open, reactor coolant pump bus undervoltage and underfrequency, turbine trip, pressurizer low pressure and pressurizer high level. On decreasing power, the above listed trips are automatically blocked.

P-8 On increasing power P-8 automatically enables reactor trips on low flow in one or more primary coolant loops, and one or more reactor coolant pump breakers open. On decreasing power, the P-8 automatically blocks the above listed trips.

P-9 On increasing power P-9 automatically enables reactor trip on turbine trip. On decreasing power P-9 automatically blocks reactor trip on turbine trip.

P-10 On increasing power P-10 allows the manual block of the Intermediate Range reactor trip and the low setpoint Power Range reactor trip; and automatically blocks the Source Range reactor trip. On decreasing power, the Intermediate Range reactor trip and the low setpoint Power Range reactor trip are automatically reactivated. Provides input to P-7.

P-13 Provides input to P-7.

SUMMER - UNIT 1 82-8 Amendment No. -34, BRN 19-001

REACTOR COOLANT SYSTEM BASES LEAKAGE DETECTION SYSTEMS (Continued)

Restoration of the required sump level monitor to OPERABLE status within a Completion Time of 30 days is required to regain the function after the monitor's failure. This time is acceptable, considering the Frequency and adequacy of the RCS water inventory balance required by the ACTION.

b. With both gaseous and particulate reactor building atmosphere radioactivity monitors inoperable, alternative action is required. Either grab samples of the containment atmosphere must be taken and analyzed or RCS water inventory balance, in accordance with surveillance requirement 4.4.6.2.1.d, must be performed to provide alternate periodic information.

With a sample obtained and analyzed or water inventory balance performed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the reactor may be operated for up to 30 days to allow restoration of the required containment atmosphere radioactivity monitors. Alternatively, continued operation is allowed if the reactor building cooling unit condensate flow rate monitor is OPERABLE, provided grab samples are taken or water inventory balances performed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> interval provides periodic information that is adequate to detect leakage. A Note 1 is added allowing that surveillance requirement 4.4.6.2.1.d is not required to be performed until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after establishing steady state operation (stable temperature, power level, pressurizer and makeup tank levels, makeup and letdown, and RCP seal injection and return flows). The 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> allowance provides sufficient time to collect and process all necessary data after stable plant conditions are established. Note 1 does not alleviate the need to comply with Action b during plant conditions that do not support performance of a RCS water inventory balance; grab sample analysis of the reactor building atmosphere should be performed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> during these times. The 30 day allowed outage time recognizes at least one other form of leakage detection is available.

c. With the reactor building cooling unit condensate flow rate monitor inoperable, alternative action is again required. Either a CHANNEL CHECK for the required reactor building atmosphere radioactivity monitor or RCS water inventory balance, in accordance with surveillance requirement 4.4.6.2.1.d, must be performed to provide alternate periodic information. Provided a CHANNEL CHECK is performed every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> or an RCS water inventory balance is performed every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, reactor operation may continue while awaiting restoration of the reactor building cooling unit condensate flow rate monitor to OPERABLE status. The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> interval provides periodic information that is adequate to detect RCS leakage. Note 1 is added allowing that surveillance requirement 4.4.6.2.1.d is not required to be performed until 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after establishing steady state operation (stable temperature, power level, pressurizer and makeup tank levels, makeup and letdown, and RCP seal injection and return flows).

The 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> allowance provides sufficient time to collect and process all necessary data after stable plant conditions are established. Note 1 does not alleviate the need to comply with Action c during plant conditions that do not support performance of a RCS water inventory balance; a CHANNEL CHECK for the required reactor building atmosphere radioactivE: monitor should be performed every 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> during these times.

SUMMER - UNIT 1 B 3/4 4-4b Amendment No. BRN 12 001 BRN 19-004

APPLICABILITY BASES For example, Technical Specification 3.6.2.1 requires two independent reactor building spray systems be OPERABLE in MODES 1, 2, 3 and 4. The ACTION Statement for this LCO states: 'With one reactor building spray system inoperable, restore the inoperable spray system to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />; restore the inoperable spray system to OPERABLE status within the next 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or be in 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 />." This ACTION Statement provides up to 156 (72 + 6 + 48 + 30) hours to achieve COLD SHUTDOWN if a reactor building spray system is discovered inoperable while in MODES 1 or 2.

If the inoperability is discovered in MODE 1 and HOT STANDBY is reached in 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />, 140 ([72 + 6-16] + 48 + 30) hours remain before being required to attain COLD SHUTDOWN (MODE 5).

If the inoperability is discovered in MODE 3, the 6-hour interval provided for achieving HOT STANDBY cannot be added to the 72-hour, 48-hour, and 30-hour intervals. Therefore, COLD SHUTDOWN would have to be attained within 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br /> (72 + 48 + 30).

If the inoperability is discovered in MODE 4, neither the 6-hour interval nor the 48-hour interval can be added to the 72-hour and 30-hour intervals. Therefore, COLD SHUTDOWN would have to be attained within 102 hours0.00118 days <br />0.0283 hours <br />1.686508e-4 weeks <br />3.8811e-5 months <br /> (72 + 30).

3.0.4 This specification provides that entry into an OPERATIONAL MODE o other specified applicability condition must be made with (a) the full complement of required systems, equipment or components OPERABLE and (b) all other parameters as specified in the Limiting Conditions for Operation being met without regard for allowable deviations and out of service provisions contained in the ACTION statements.

The intent of this provision is to insure that facility operation is not initiated with either required equipment or systems inoperable or other specified limits being exceeded.

Exceptions to this provision have been provided for a limited number of specifications when startup with inoperable equipment would not affect plant safety. These exceptions are stated in the ACTION statements of the appropriate specifications.

4.0.1 Technical Specification 4.0.1 establishes the requirement that surveillance requirements (SR) must be met during the MODES or other specified conditions in the Applicability for which the requirements of the LCO apply, unless otherwise specified in the individual SRs. This specification is to ensure that surveillances are performed to verify the OPERABILITY of systems and components, and that variables are within specified limits.

Failure to meet a SR within the specified frequency, in accordance with 4.0.2, constitutes a failure to meet an LCO.

Surveillances may be performed by means of any series of sequential, overlapping, or total steps provided the entire Surveillance is performed within the specified Frequency.

Additionally, the definitions related to instrument testing (e.g., CHANNEL CALIBRATION) specify that these tests are performed by means of any series of sequential, overlapping, or total steps.

SUMMER - UNIT 1 B 3/4 0-2 Amendment No. BRN 04 001, BRN 18 003, BRN 20-001