ML20121A185

License Amendment Request LAR-20-142 - Request for Technical Specification Change Technical Specification 3.6.4, Containment Isolation Valves

ML20121A185
Person / Time
Site:	Summer
Issue date:	04/30/2020
From:	Mark D. Sartain Dominion Energy South Carolina
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LAR-20-142
Download: ML20121A185 (23)

Text

Dominion Energy South Carolina, Inc.

5000 Dominion Boulevard, Glen Allen, VA 23060 DominionEnergy.com April 30 , 2020 Attn: Document Control Desk Serial No .: 20-142 U. S. Nuclear Regulatory Commission NRA/YG : 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 LICENSE AMENDMENT REQUEST LAR-20-142 REQUEST FOR TECHNICAL SPECIFICATION CHA NG E TECHNICAL SPECIFICATION 3.6.4, "CONTAINME NT ISOLATION VALVES" Pursuant to 10 CFR 50 .90 , Dominion Energy South Carolina (DESC) acting for itself and as an agent for South Carolina Public Service Authority hereby requests an amendment to the Technical Specifications (TS) for V.C. Summer Nuclear Station Unit 1. The proposed amendment would modify Action statem ents in TS 3.6.4 , "Containment Isolation Valves ."

Specifically , the proposed amendment would replace the word "valve" with the word "barrier" , and the words "each affected penetration that is open " with "the affected penetration(s)" in the TS 3.6.4 Action statements. The term "barrier" as used in the TS 3.6.4 Action statements is described in the revised TS 3.6.4 Bases to be synonymous with either an isolation valve , blind flange , or a closed system that is associated with containment penetrations that conform to GDC 57 applications for closed system isolation valves .

The proposed amendment would also replace two instances of "penetration " with "penetration flow path" . The current VCSNS TS 3.6.4 does not differentiate between "penetration " and "penetration flow path " and could be interpreted to require isolation of a penetration when only isolation of the flow path is required to maintain containment integrity. The current wording could result in an unnecessary plant shutdown.

The enclosure provides a description and assessment of the proposed amendment. provides the existing TS pages marked -up to show the proposed changes. provides the revised (clean) TS pages . Attachment 3 provides existing TS Bases pages marked-up to show the proposed changes for information only .

DESC requests NRC review and approval of the proposed amendment by April 30 , 2021.

Once approved , the amendment shall be implemented within 60 days.

In accordance with 10 CFR 50 .91 , a copy of this appl ication , with attachments , is being provided to the designated South Carolina Official.

Should you have any questions or require additional info rmation , please call Yan Gao at (804) 273-2768.

Serial No.20-142 Docket No.: 50-395 Page 2 of 3 Res pectfuIly,

~~~

Mark Sartain Vice President-Nuclear Engineering & Fleet Support Dominion Energy South Carolina, Inc.

COMMONWEAL TH 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 Dominion Energy South Carolina, Inc. 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 ~ day of t\pv I I ,2020.

My Commission Expires: J.1)ar('13f, 2J>Z2 DIANE E. AITKEN NOTARY PUBLIC

,~*z.k-bNotary Public REG. #7763114 COMMONWEALTH OFVIAGINIA MY COMMISSION EXPIRES MARCH 31, 2022 Commitments contained in this letter: None

Enclosure:

Description and Assessment of the Proposed Changes Attachments:

1. Proposed Technical Specification Change (Mark-up)

2. Proposed Technical Specification Change (Re-typed)

3. Existing TS Bases Pages Marked to Show the Proposed Changes

Serial No.20-142 Docket No.: 50-395 Page 3 of 3 cc: U.S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Avenue, NE Suite 1200 Atlanta, GA 30303-1257 Mr. Shawn Williams NRC Project Manager U.S. Nuclear Regulatory Commission Mail Stop 08 B 1A One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738 NRC Senior Resident Inspector V. C. Summer Nuclear Station Ms. Anuradha Nair-Gimmi Bureau of Environmental Health Services South Carolina Department of Health and Environmental Control 2600 Bull Street Columbia, SC 29201 Mr. G. J. Lindamood Santee Cooper - Nuclear Coordinator 1 Riverwood Drive Moncks Corner, SC 29461

Serial No.20-142 Docket No.: 50-395 ENCLOSURE DESCRIPTION AND ASSESSMENT OF THE PROPOSED CHANGES License Amendment Request LAR-20-142 Request for Technical Specification Change Technical Specification 3.6.4, "Containment Isolation Valves"

1.

SUMMARY

DESCRIPTION

2. DETAILED DESCRIPTION 2.1 System Design and Operation 2.2 Current Technical Specifications Requirements 2.3 Reason for the Proposed Change 2.4 Description of the Proposed Change

3. TECHNICAL EVALUATION

4. REGULATORY EVALUATION 4.1 Applicable Regulatory Requirements/Criteria 4.2 Precedent 4.3 No Significant Hazards Consideration Analysis 4.4 Conclusions

5. ENVIRONMENTAL CONSIDERATION

6. REFERENCES ATTACHMENTS:

1. Existing TS Pages Marked to Show the Proposed Changes

2. Revised (Clean) TS Pages

3. Existing TS Bases Pages Marked to Show the Proposed Changes Virgil C. Summer Nuclear Station Unit 1 Dominion Energy South Carolina, Inc.

Serial No.20-142 Docket No.: 50-395 Enclosure Page 1 of 11 1.0

SUMMARY

DESCRIPTION Changes are proposed to TS 3.6.4 Action statements. Specifically, changes are proposed to replace the word "valve" with the word "barrier", and the words "each affected penetration that is open" with "the affected penetration(s)" in these TS 3.6.4 Action statements. The term "barrier" as used in the TS 3.6.4 Action is described in the revised TS 3.6.4 Bases to be synonymous with either an isolation valve, blind flange, or a closed system that is associated with containment penetrations that conform to GDC 57 applications for closed system isolation valves.

The proposed amendment would also replace two instances of "penetration" with "penetration flow path". The current VCSNS TS 3.6.4 does not differentiate between "penetration" and "penetration flow path" and could be interpreted to require isolation of a penetration when only isolation of the flow path is required to maintain containment integrity. The current wording of TS 3.6.4 could result in an unnecessary plant shutdown.

2.0 DETAILED DESCRIPTION 2.1 System Design and Operation The containment isolation system is discussed in Section 6.2.4 of the VCSNS Final Safety Analysis Report (FSAR).

The objective of the containment isolation system is to allow the passage offluids through the containment boundary under normal and accident conditions, while preserving the integrity of the containment boundary when required to prevent or limit the escape of fission products as a result of a postulated Loss of Coolant Accident (LOCA).

The containment isolation system is not an independent system. Rather, the system is comprised of specific provisions included in each piping system that penetrates the Reactor Building. Actuation of containment isolation is accomplished through the Engineered Safety Features Actuation System (ESFAS).

In the unlikely event of a LOCA, the containment isolation system is designed to limit leakage of radioactive materials through lines penetrating the Reactor Building so that the site boundary dose guidelines specified in 10 CFR 50.67 are not exceeded.

Lines for which isolation is required are provided with two barriers, such that no single failure can prevent isolation. Each of these barriers is adequate to limit leakage of radioactivity within acceptable values over the entire range of normal and accident conditions.

An "isolation barrier" is either an isolation valve, blind flange, or a closed system. A closed system is defined as a fluid system which is not part of the Reactor Coolant System and which does not communicate with the Reactor Building atmosphere.

Serial No.20-142 Docket No.: 50-395 Enclosure Page 2 of 11 Fluid systems, including instrument lines, penetrating the Reactor Building satisfy the following specific design bases:

1. The design of isolation barriers for lines penetrating the Reactor Building follows the requirements of General Design Criteria 54 through 57 of 10 CFR 50, Appendix A.

2. The containment isolation system is protected against the effects of missiles and postulated pipe ruptures, as discussed in FSAR Section 3.5 and 3.6.

3. The containment isolation system is designed to Safety Class 2a, Seismic Category 1 requirements. Regulatory Guides 1.26 and 1.29 are discussed in Appendix 3A of the VCSNS FSAR.

4. The containment isolation system is designed with redundancy in accordance with General Design Criterion 54 so that no single active failure can result in loss of containment integrity.

5. The containment isolation system is designed to withstand accident environmental conditions, as discussed in VCSNS FSAR section 3.11.

6. Provisions are made for periodically testing the operability and leak tightness of the containment isolation valves to the extent necessary to ensure that the system satisfies performance requirements in the event of an accident.

2.2 Current Technical Specifications Requirements Technical Specification (TS) 3/4.6.4, "Containment Isolation Valves," contains the requirements for CIVs. TS 3.6.4 provides the Limiting Condition for Operation (LCO) for CIVs and states:

"Each containment isolation valve shall be OPERABLE*.

• Locked or sealed closed valves may be opened on an intermittent basis under administrative control."

This TS 3/4.6.4 is applicable in MODES 1, 2, 3, and 4. The Action statements are as follows:

With one or more of the isolation valve(s) inoperable, maintain at least one isolation valve OPERABLE in each affected penetration that is open and either:

a. Restore the inoperable valve(s) to OPERABLE status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, or

b. Isolate each affected penetration within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by use of at least one deactivated automatic valve secured in the isolation position, or

Serial No.20-142 Docket No.: 50-395 Enclosure Page 3 of 11

c. Isolate each affected penetration within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by use of at least one closed manual valve or blind flange, or

d. 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 /> and in COLO 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 provisions of Specification 3.0.4 do not apply.

VCSNS TS are not based on the Standard Technical Specifications (STS) of NUREG 1431, "Standard Technical Specifications: Westinghouse Plants," however the relevant differences are described below.

NUREG 1431, Revision 4 discusses Containment Isolation Valves in Section 3.6.3.

NUREG 1431, Revision 4 currently incorporates TSTF-446, "Risk-Informed Evaluation of Extensions to Containment Isolation Valve Completion Times (WCAP-15791 )." This TSTF allows extensions of CIV completion times based on the evaluation provided in WCAP-15791, "Risk-Informed Evaluation of Extensions to Containment Isolation Valve Completion Times." VCSNS is not proposing adoption of TSTF-446, and therefore is retaining the current completion time for inoperable Containment Isolation Valves in TS 3.6.4 Actions a, b, and c. Similar to the VCSNS proposed changes, NUREG 1431 uses the term "penetration flow path" and credits closed systems as isolation barriers.

2.3 Reason for the Proposed Change In the event a CIV becomes inoperable, the current TS 3.6.4 requires the station to maintain at least one isolation valve OPERABLE in each affected penetration. If the affected penetration consists of only one CIV and a closed system, immediate shutdown would be required. Changes to the TS 3.6.4 Action statement are proposed to replace the word "valve" with the word "barrier". The word "barrier" in this Action is described by a revision to the TS 3.6.4 Bases as synonymous with either a CIV, a blind flange or a closed system that is associated with containment penetrations that conform to GDC 57 applications for closed system isolation valves.

Additionally, it is proposed to replace the words "each affected penetration that is open" with "the affected penetration(s)" in the TS 3.6.4 Action. This change is an editorial change to clarify the Action text without modifying the Action's meaning.

A change is also being requested to incorporate the term "penetration flow path" in place of "penetration" into TS 3.6.4. The current TS 3.6.4 does not differentiate between "penetration" and "penetration flow path". In the event a CIV is inoperable and there are multiple CIVs in the affected penetration, the current TS could be interpreted to require isolation of all valves in the affected penetration, regardless of operability. This condition could result in an unnecessary plant shutdown. This change clarifies the station's desire to only isolate the inoperable valve in the affected flow path that is required to maintain containment integrity. This change will clarify that only the affected penetration flow path needs to be isolated and not all valves in the penetration.

Serial No.20-142 Docket No.: 50-395 Enclosure Page 4 of 11 2.4 Description of the Proposed Change Changes to TS 3/4.6.4 are proposed as follows:

1. Modify the wording of the Action statement for TS 3.6.4 from "maintain at least one isolation valve OPERABLE in each affected penetration that is open and either:"

to "maintain at least one isolation barrier OPERABLE in the affected penetration(s) and:".

2. Action statements "b" and "c" will use the term "penetration flow path" instead of "penetration".

The proposed TS changes are shown on the marked-up TS page provided in Attachment

1. The proposed retyped TS page is provided in Attachment 2.

The proposed TS 3.6.4 changes are supported by associated changes to the TS Bases.

In addition to reflecting the proposed changes to the TS, the TS 3.6.4 Bases are being revised for clarity and consistency. The regulation at Title 10 of the Code of Federal Regulations (10 CFR), Part 50.36(a)(1 ), states, "A summary statement of the bases or reasons for such specifications, other than those covering administrative controls, shall also be included in the application, but shall not become part of the technical specifications." Changes to the TS Bases will be made in accordance with the Technical Specifications Bases Control Program following approval of the requested amendment.

The Bases changes are provided for information and approval of the Bases is not requested.

3.0 TECHNICAL EVALUATION

Changes to the TS 3.6.4 Action statements are being proposed. Specifically, replacement of the word "valve" with the word "barrier", and the words "each affected penetration that is open" with "the affected penetration(s)" is being proposed. The term "barrier" as used in the TS 3.6.4 Action is described by the revised TS 3.6.4 Bases to be synonymous with either a CIV, a blind flange or the closed system that is associated with containment penetrations that conform to GDC 57 applications for closed system isolation valves. This change is consistent with the intent of the of the TS, which is to ensure that the reactor building atmosphere will be isolated from the outside environment in the event of a release of radioactive material to the reactor building atmosphere or pressurization of the reactor building. General Design Criteria (GDC) 57 allows the use of a closed system in combination with a CIV to provide two containment barriers against the release of radioactive material following an accident. The words "each affected penetration that is open" are synonymous with the proposed words that state "the affected penetration(s)".

The changes are proposed to improve consistency in the format of the TS 3.6.4 Action text without modifying the Action's applicability or the TS 3.6.4 operability requirements.

Serial No.20-142 Docket No.: 50-395 Enclosure Page 5 of 11 A change is being requested to TS 3.6.4 incorporate the term "penetration flow path" in place of "penetration". The current TS does not differentiate between "penetration" and "penetration flow path". In the event a CIV is inoperable and there are multiple CIVs in the affected penetration, the current TS can be interpreted to require isolation of all valves in the affected penetration, regardless of operability. The proposed change clarifies the station's desire to only isolate the inoperable valve in the affected flow path that is needed to maintain containment integrity. This change will clarify that only the affected penetration flow path needs to be isolated and not all valves in the penetration. This change is consistent with the intent of the TS, which is to ensure that the reactor building atmosphere will be isolated from the outside environment in the event of a release of radioactive material to the reactor building atmosphere or pressurization of the reactor building.

4.0 REGULATORY EVALUATION

4.1 Applicable Regulatory Requirements/ Criteria The following NRC requirements and guidance documents are applicable to the proposed change.

The regulations at Title 10 of the Code of Federal Regulations (10 CFR) Part 50.36, "Technical specifications," establish the requirements related to the content of the TS.

Section 50.36(c)(2) states:

"Limiting conditions for operation. 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. JI The regulatory requirements in 10 CFR 50.36 are not specific regarding the actions to be followed when TS requirements are not met other than a plant shutdown. The proposed change modifies the wording of remedial actions in the Technical Specifications to be followed when the Limiting Condition for Operation is not met. Therefore, the proposed change is consistent with the requirements of 10 CFR 50.36(c)(2).

The regulations at Title 10 of the Code of Federal Regulations (10 CFR) Section 50.36(c)(3) states:

"Surveillance requirements. Surveillance requirements are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions for operation will be met. JI

Serial No.20-142 Docket No.: 50-395 Enclosure Page 6 of 11 The regulatory requirements in 10 CFR 50.36 are not specific regarding the surveillance requirements other than to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions for operation will be met. The proposed change is consistent with the requirements of 10 CRF 50.36(c)(3).

The construction permit for V.C. Summer Unit 1 was issued by the Atomic Energy Commission (AEC) on March 21, 1973. The Operating License was issued on August 6, 1982. NUREG 0717, "Safety Evaluation Report related to the operation of Virgil C.

Summer Nuclear Station," discusses V.C. Summer's conformance with the General Design Criteria. In a letter dated November 14, 1980, V.C. Summer addressed compliance with 10 CFR Parts 20, 50, and 100 including the General Design Criteria.

The NRC evaluated the final design and the design criteria and concluded, subject to the applicant's adoption of the additional requirements imposed by the NRC as discussed in the Safety Evaluation Report, that the facility had been designed to meet the requirements of the General Design Criteria. In the November 14, 1980 letter, V.C. Summer provided a discussion to compare the plant design with the General Design Criteria (GDC) as they appeared in 10 CFR 50 Appendix A. It was this discussion, including the identified exceptions, which formed the original plant licensing basis for compliance with the GDC.

This discussion is contained in the UFSAR Section 3.0, "General Design Criteria," with more details provided in other UFSAR sections. Changes have been made to the original UFSAR GDC discussions to reflect commitments and changes made to the facility over the life of the plant. Therefore, the GDC discussions in the UFSAR constitute the V.C.

Summer Unit 1 licensing bases with respect to compliance with the GDC.

4.1.1 GDC 54-57 The design of isolation barriers for lines penetrating the reactor building follows the requirements General Design Criterion (GDC) 54 through 57 of 10 CFR 50, Appendix A.

Criterion 54 - Piping systems penetrating containment. Piping systems penetrating primary reactor containment shall be provided with leak detection, isolation, and containment capabilities having redundancy, reliability, and performance capabilities which reflect the importance to safety of isolating these piping systems. Such piping systems shall be designed with a capability to test periodically the operability of the isolation valves and associated apparatus and to determine if valve leakage is within acceptable limits.

The containment isolation system is designed with redundancy in accordance with General Design Criterion 54 so that no single active failure can result in a loss of containment integrity. The proposed change does not constitute a change to the design of the piping systems penetrating primary reactor containment with respect to the associated leak detection, isolation, and containment capabilities.

The proposed change does not affect the capability to test periodically the operability of the isolation valves and associated apparatus and to determine if valve leakage is within acceptable limits. Although the LCO for valves associated with GDC 54 will be reworded

Serial No.20-142 Docket No.: 50-395 Enclosure Page 7 of 11 for clarity, there is no change to the design of the isolation valves within the scope of GDC 54.

Criterion 55-Reactor coolant pressure boundary penetrating containment. Each line that is part of the reactor coolant pressure boundary and that penetrates primary reactor containment shall be provided with containment isolation valves as follows, unless it can be demonstrated that the containment isolation provisions for a specific class of lines, such as instrument lines, are acceptable on some other defined basis:

(1) One locked closed isolation valve inside and one locked closed isolation valve outside containment; or (2) One automatic isolation valve inside and one locked closed isolation valve outside containment; or (3) One locked closed isolation valve inside and one automatic isolation valve outside containment. A simple check valve may not be used as the automatic isolation valve outside containment; or (4) One automatic isolation valve inside and one automatic isolation valve outside containment. A simple check valve may not be used as the automatic isolation valve outside containment.

Isolation valves outside containment shall be located as close to containment as practical and upon loss of actuating power, automatic isolation valves shall be designed to take the position that provides greater safety.

Other appropriate requirements to minimize the probability or consequences of an accidental rupture of these lines or of lines connected to them shall be provided as necessary to assure adequate safety. Determination of the appropriateness of these requirements, such as higher quality in design, fabrication, and testing, additional provisions for inservice inspection, protection against more severe natural phenomena, and additional isolation valves and containment, shall include consideration of the population density, use characteristics, and physical characteristics of the site environs.

The proposed change does not constitute a change to the design of the piping systems penetrating primary reactor containment or the associated containment isolation valves.

Although the LCO for valves associated with GDC 55 will be reworded for clarity, there is no change to the design of the isolation valves within the scope of GDC 55.

Criterion 56 - Primary containment isolation. Each line that connects directly to the containment atmosphere and penetrates primary reactor containment shall be provided with containment isolation valves as follows, unless it can be demonstrated that the containment isolation provisions for a specific class of lines, such as instrument lines, are acceptable on some other defined basis:

Serial No.20-142 Docket No.: 50-395 Enclosure Page 8 of 11 (1) One locked closed isolation valve inside and one locked closed isolation valve outside containment; or (2) One automatic isolation valve inside and one locked closed isolation valve outside containment; or (3) One locked closed isolation valve inside and one automatic isolation valve outside containment. A simple check valve may not be used as the automatic isolation valve outside containment; or (4) One automatic isolation valve inside and one automatic isolation valve outside containment. A simple check valve may not be used as the automatic isolation valve outside containment.

Isolation valves outside containment shall be located as close to the containment as practical and upon loss of actuating power, automatic isolation valves shall be designed to take the position that provides greater safety.

The proposed change does not constitute a change to the design of the piping systems penetrating primary reactor containment or the associated containment isolation valves.

Although the LCO for valves associated with GDC 56 will be reworded for clarity, there is no change to the design of the isolation valves within the scope of GDC 56.

Criterion 57-Closed system isolation valves. Each line that penetrates primary reactor containment and is neither part of the reactor coolant pressure boundary nor connected directly to the containment atmosphere shall have at least one containment isolation valve which shall be either automatic, or locked closed, or capable of remote manual operation. This valve shall be outside containment and located as close to the containment as practical. A simple check valve may not be used as the automatic isolation valve.

The proposed change does not constitute a change to the design of the piping systems penetrating primary reactor containment or the associated closed system isolation valves.

The proposed change will only modify the required actions in the event a closed system isolation valve does not meet the LCO. Although the LCO for valves associated with GDC 57 will be reworded for clarity, there is no change to the design of the isolation valves within the scope of GDC 57.

The proposed change does not affect plant compliance with these regulations and will continue to ensure that the lowest functional capabilities or performance levels of equipment required for safe operation continue to be met.

4.2 Precedent Millstone Unit 3 submitted a proposed change which, in part, made similar clarifications regarding the use of a closed system as an isolation barrier and the addition of the term "flow path". This application for amendment was submitted on August 14, 2002 and

Serial No.20-142 Docket No.: 50-395 Enclosure Page 9 of 11 supplemented on December 19, 2002. This change was approved by the NRC on September 29, 2003 [ML031670914].

4.3 No Significant Hazards Consideration Determination Analysis A change is being proposed to TS 3.6.4 to use the term "penetration flow path" instead of "penetration". The current VCSNS TS does not differentiate between "penetration" and "penetration flow path". The current TS could be interpreted to require isolation of a penetration when the intent is to only isolate the flow path.

Changes to the TS 3.6.4 Action statements are proposed to replace the word "valve" with the word "barrier", and the words "each affected penetration that is open" with "the affected penetration(s)" in the statement. The term "barrier" as used in the TS 3.6.4 Action statements is described by a proposed revision to TS 3.6.4 Bases to be synonymous with either a Containment Isolation Valve (CIV), a blind flange or the closed system that is associated with containment penetrations that conform to GDC 57 applications DESC has evaluated whether a significant hazards consideration is involved with the proposed amendment by focusing on the three standards set forth in 10 CFR 50.92, "Issuance of amendment," as discussed below:

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

Response: No.

The proposed changes do not adversely affect any accident initiators or precursors.

The proposed changes do not alter the design assumptions, conditions, or configuration of the facility or the manner in which the plant is operated and maintained. The proposed changes do not alter or prevent the ability of structures, systems, and components (SSCs) from performing their intended function to mitigate the consequences of an initiating event within the assumed acceptance limits. The proposed changes do not affect the source term, containment isolation, or radiological release assumptions used in evaluating the radiological consequences of an accident previously evaluated. In addition, the proposed changes do not increase the types or amounts of radioactive effluent that may be released offsite, nor significantly increase individual or cumulative occupational/public radiation exposures. The proposed changes are consistent with the safety analysis assumptions and resultant consequences.

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

2. Does the proposed change create the possibility of a new or different accident from any accident previously evaluated?

Response: No.

Serial No.20-142 Docket No.: 50-395 Enclosure Page 1O of 11 The proposed changes do not result in a change to the manner in which the containment isolation valves provide accident mitigation. There are no design changes associated with the proposed changes. The proposed changes do not change any existing accident scenarios or create any new or different accident scenarios.

The changes do not involve a physical alteration of the plant (i.e., no new or different type of equipment will be installed) or a change in the methods governing normal plant operation. In addition, the changes do not impose any new or different requirements or eliminate any existing requirements. The changes do not alter assumptions made in the safety analysis. The proposed changes are consistent with the safety analysis assumptions and current plant operating practice.

Therefore, the proposed changes do not create the possibility of a new or different accident from any accident previously evaluated.

3. Does the proposed change involve a significant reduction in a margin of safety?

Response: No.

The proposed changes do not alter the manner in which safety limits, limiting safety system settings, or limiting conditions for operation are determined. The safety analysis acceptance criteria are not impacted by these changes. The proposed changes will not result in plant operation in a configuration outside the design basis.

Therefore, the proposed changes do not involve a significant reduction in a margin of safety.

Based on the above evaluation, DESC concludes that the proposed changes present no significant hazards consideration under the standards set forth in 10 CFR 50.92(c), and accordingly, a finding of "no significant hazards consideration" is justified.

4.4 Conclusion In conclusion, based on the considerations discussed above, (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.

5.0 Environmental Consideration A review has determined that the proposed amendment would change a requirement with respect to installation or use of a facility component located within the restricted area, as defined in 10 CFR 20, or would change an inspection or surveillance requirement.

Serial No.20-142 Docket No.: 50-395 Enclosure Page 11 of 11 However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or a significant increase in the amounts of any effluents that may be released offsite, or (iii) a significant increase in individual or cumulative occupational radiation exposure. Accordingly, the proposed amendment meets the eligibility criterion for categorical exclusion set forth in 10 CFR 51.22(c)(9).

Therefore, pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the proposed amendment.

6.0 REFERENCES

1. U.S. Code of Federal Regulations 10 CFR 50, Appendix A, "General Design Criteria for Nuclear Power Plants"

2. VCSNS FSAR Chapter 6, Section 6.2.4, "Containment Isolation System"

3. Regulatory Guide 1.26, Revision 3, "Quality Group Classification and Standards for Water, Steam, and Radioactive Waste Containing Components of Nuclear Power Plants"

4. Regulatory Guide 1.29, Revisions 2 and 4, "Seismic Design Classification"

5. VCSNS FSAR Chapter 3, Section 3.11, "Environmental Qualification of Mechanical and Electrical Equipment"

Serial No.20-142 Docket No.: 50-395 Attachment 1 ATTACHMENT 1 PROPOSED TECHNICAL SPECIFICATION CHANGE (MARK-UP)

Virgil C. Summer Nuclear Station Unit 1 Dominion Energy South Carolina, Inc.

• CO.tiIAIHMEHT ~YSTEMS 3LS.,.6.4 CONTAINMENT ISOLATION VA~VES LIMITING COHOITIOH FOR OPERATION 3.6.4 E_4.ch containment isolation valve shall be OPERABLE ....

APPLICAB~LITY: MOOES 1, 2, 3 and 4.

~

ACTION:

the With one or more of the isolat n (s) inoperable, maintain at least one isolation ¥a-t-Ye OPERABLE in affected penetration that is epen and either: ~ ~

a. Restore the inoperable valve(s) to OPERABLE status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

or ~

b. 1solate each affected penetration within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by use of at least one deactivated automatic valve secur

• isolation posit1on. or flow path

c. Isolate each affected penetration wit 1n hours by use of at le~st one closed manual valve or blind flange, or

• d. 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 /> and in COLD SHUTDOWN within the fo11owing 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

The provisions of Specification 3.0.4 do not apply.

SURVEILLANCE REQUI~EMENT~

4.6.4.1 Each containment isolation valve shall be demonstrated OPERABLE prior to returning the valve to service after maintenance. repair, or replacement work is performed on the valve or its associated actuator, control, or power circuit by performance of a cycling test and verification of isolation time.

4.6.4.2 Each containment isolation valve sha11 be demonstrated OPERABLE during the COLD SHUTDOWN or REFUELING MODE AT LEAST ONCE PER 18 MONTHS BY:

a. Ver1fy1ng that on a Phase A containment isolation test signal, each Phase A isolation valve actuates to its isolation position.

b. Verifying that on a Phase S containment isolation test signal. each Phase a isolation valve actuates to its isolation position.

c. Verifying that on a Reactor Building Purge and Exhaust isolation test signal. each Purge and Exh&ist valve actuates to its isolation position.

• Locked or sealed closeo vaives may be opened on an intermittent basis under administrative control.

SUMMER - UH IT 1 3/4 6-17 Amendment No. 110

Serial No.20-142 Docket No.: 50-395 Attachment 2 ATTACHMENT 2 PROPOSED TECHNICAL SPECIFICATION CHANGE (RETYPED)

Virgil C. Summer Nuclear Station Unit 1 Dominion Energy South Carolina, Inc.

CONTAINMENT SYSTEMS 3/4.6.4 CONTAINMENT ISOLATION VALVES LIMITING CONDITION FOR OPERATION 3.6.4 Each containment isolation valve shall be OPERABLE.

• APPLICABILITY: MODES 1, 2, 3 and 4.

ACTION:

With one or more of the isolation valve(s) inoperable, maintain at least one isolation barrier OPERABLE in the affected penetration(s) and :

a. Restore the inoperable valve(s) to OPERABLE status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, or

b. Isolate each affected penetration flow path within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by use of at least one deactivated automatic valve secured in the isolation position, or

c. Isolate each affected penetration flow path within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> by use of at least one closed manual valve or blind flange, or

d. 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 /> and 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 />.

The provisions of Specification 3.0.4 do not apply .

SURVEILLANCE REQUIREMENTS 4.6.4.1 Each containment isolation valve shall be demonstrated OPERABLE prior to returning the valve to service after maintenance, repair, or replacement work is performed on the valve or its associated actuator, control, or power circuit by performance of a cycling test and verification of isolation time.

4.6.4.2 Each containment isolation valve shall be demonstrated OPERABLE during the COLD SHUTDOWN or REFUELING MODE AT LEAST ONCE PER 18 MONTHS BY:

a. Verifying that on a Phase A containment isolation test signal, each Phase A isolation valve actuates to its isolation position.

b. Verifying that on a Phase B containment isolation test signal, each Phase B isolation valve actuates to its isolation position.

c. Verifying that on a Reactor Building Purge and Exhaust isolation test signal, each Purge and Exhaust valve actuates to its isolation position.

• Locked or sealed closed valves may be opened on an intermittent basis under administrative control .

SUMMER - UNIT 1 3/4 6-17 Amendment No. xxx

Serial No.20-142 Docket No.: 50-395 Attachment 3 ATTACHMENT 3 Existing TS Bases Pages Marked to Show the Proposed Changes (Basis Changes are for NRC Information Only)

Virgil C. Summer Nuclear Station Unit 1 Dominion Energy South Carolina, Inc.

CONTAINMENT SYSTEMS BASES opening of valves XVB-3107A(B)-SW, the air in the piping will act as a cushion to minimize any water hammer affects that could occur downstream of XVB-3107A(B)-SW.

The opening logic of valves XVB-3107 A(B )-SW has a delayed opening after valve 3106A(B)-SW begins to open. The delay allows fluid flow momentum to build to assure that additional void formation in the RBCU piping inside containment will not occur during swap over to the SW system.

To minimize the effects of the second water hammer scenario XVB-3107A(B)-SW, fast closing air operated butterfly valves, close in seven seconds upon de-energizing of the SWBPs. During times that the RBCUs are aligned with the SW system, if a LOOP were to occur, the fast valve closure will trap water in the high points above the valve and prevent void formation due to gravity drain down of the water to the SW pond. Interface logic is provided to equipment controls that tie the start of the respective SWBP to the closed position of the respective valve XVB-3107A(B)-SW. The controls prevent a SWBP start if the respective valve XVB-3107A(B)-SW failed to fully close allowing drain down of the water to the SW Pond.

The accident analysis requires the service water booster pump to be passing 2,000 gpm to each selected RBCU within 86.5 seconds. This time encompasses the driving of all necessary service water valves to the correct positions, i.e., fully opened or fully closed. Reference Technical Specification Bases B 3/4.3.1 and B 3/4.3.2 for additional details.

3/4.6.3 PARTICULATE IODINE CLEANUP SYSTEM The OPERABILITY of the containment filter trains ensures that sufficient iodine removal capability will be available in the event of a LOCA. The reduction in containment iodine inventory reduces the resulting site boundary radiation doses associated with containment leakage. The operation of this system and resultant iodine removal capacity are consistent with the assumptions used in the LOCA analyses.

3/4.6.4 CONTAINMENT ISOLATION YAI VEa. !Insert 1 I

-,E The OPERABILITY of the containment isolation valves ensures that the reactor building atmosphere will be isolated from the outside environment in the event of a release of radioactive material to the reactor building atmosphere or pressurization of the reactor building and is consistent with the requirements of GDC 54 through 57 of Appendix A to 10 CFR Part 50. Containment isolation within the time limits required by the safety analysis for those isolation valves designed to close automatically ensures that the release of radioactive material to the environment will be consistent with the assumptions used in the analyses for a LOCA.

SUMMER - UNIT 1 B 3/4 6-5 Amendment No. 44G,

@RN--Og_QQ-l, BRN-10-001

CONTAINMENT SYSTEMS BASES The opening of locked or sealed closed containment isolation valves on an intermittent basis under administrative control includes the following considerations:

(1) stationing an operator, who is in constant communication with control room, at the valve controls, (2) instructing this operator to close these valves in an accident situation, and (3) assuring that environmental conditions will not preclude access to close the valves.

3/4.6.5 COMBUSTIBLE GAS CONTROL The OPERABILITY of the equipment and systems required for the detection and control of hydrogen gas ensures that this equipment will be available to maintain the hydrogen concentration within the reactor building below its flammable limit during post-LOCA conditions. Either recombiner unit (or the purge system) is capable of controlling the expected hydrogen generation associated with 1) zirconium-water reactions,

2) radiolytic decomposition of water, and 3) corrosion of metals within containment.

These hydrogen control systems are consistent with the recommendations of Regulatory Guide 1.7, "Control of Combustible Gas Concentrations in Containment Following a LOCA," March 1971.

The hydrogen mixing systems are provided to ensure adequate mixing of the containment atmosphere following a LOCA. This mixing action will prevent localized accumulations of hydrogen from exceeding the flammable limit.

SUMMER - UNIT 1 B 3/4 6-6 Amendment No. 44G, BRN-08-001

Insert 1 The containment isolation valves form part of the containment pressure boundary and provide a means for fluid penetrations not serving accident consequence limiting systems to be provided with two isolation barriers that are closed on a containment isolation signal. These isolation barriers are either passive or active (automatic). Manual valves, de-activated automatic valves secured in their closed position, blind flanges, and closed systems are considered passive isolation barriers. Automatic valves designed to close without operator action following an accident are considered active isolation barriers. Two barriers in series are provided for each penetration so that no single credible failure or malfunction of an active component can result in a loss of isolation or leakage that exceeds limits assumed in the safety analyses. One of these barriers may be a closed system. An inoperable valve may be used to isolate the affected penetration per TS 3.6.4.b/c if the valve is in the closed position (i.e. failed closed or stuck closed) and has power removed, if so equipped.