ML081070126
ML081070126 | |
Person / Time | |
---|---|
Site: | Sequoyah |
Issue date: | 04/15/2008 |
From: | Thompson R Tennessee Valley Authority |
To: | Document Control Desk, Office of Nuclear Reactor Regulation |
References | |
TVA-SQN-TS-08-02 | |
Download: ML081070126 (104) | |
Text
Tennessee Valley Authority, Post Office Box 2000, Soddy-Daisy, Tennessee 37379-2000 April 15,2008 TVA-SQN-TS-08-02 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001 Gentlemen:
In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority (TVA) ) 50-328 SEQUOYAH NUCLEAR PLANT (SQN) - UNITS 1 AND 2 - TECHNICAL SPECIFICATIONS (TS) CHANGE 02 "CONTAINMENT PURGE TIME LIMIT AND CONSOLIDATION OF CONTAINMENT ISOLATION VALVE SPECIFICATIONS" Pursuant to 10 CFR 50.90, Tennessee Valley Authority (TVA) is submitting a request for a TS change (TS-08-02) to Licenses DPR-77 and DPR-79 for SQN. The proposed TS change will change and realign several containment isolation subject matter TSs to NUREG-1431, Revision 3, "Standard Technical Specifications Westinghouse Plants." A primary intent is to eliminate the cumulative time limit of 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> per year for purge and vent valves operation for TS Limiting Condition of Operation (LCO) 3.6.1.9, "Containment Ventilation System." Recently, the cumulative time limit has proved challenging, so much so a temporary change to increase the time limit for Unit 2 operation in 2007 was necessary. TVA informed NRC of its intent to pursue a permanent change for purging and venting of SQN units and by this request fulfills our intent. Changing LCO 3.6.1.9 also provides an opportunity to revise and align two other LCO's, 3.6.1.2, "Secondary Containment Bypass Leakage" and 3.6.3, "Containment Isolation" with NUREG-1431.
TVA has determined that there are no significant hazards considerations associated with the proposed change and that the TS change qualifies for categorical exclusion from environmental review pursuant to the provisions of 10 CFR 51.22(c)(9). Additionally, in accordance with 10 CFR 50.91 (b)(1), TVA is sending a copy of this letter and enclosures to the Tennessee State Department of Public Health.
Printed on recycled paper
U.S. Nuclear Regulatory Commission Page 2 April 15, 2008 Currently, there is no specific date or milestone by which approval of this amendment is required and that the implementation of the revised TSs be within 60 days of NRC approval. However, if planned corrective maintenance activities do not mitigate the need for containment purge and ventilation operations, expedited review may be requested.
This approval date is based on current projected operation of the purge and ventilation system.
There are no regulatory commitments associated with this submittal.
If you have any questions about this change, please contact me at 843-6672.
I declare under penalty of perjury that the foregoing is true and correct. Executed on this 15th day of April, 2008.
Sincerely, Russell R. Thompson Site Licensing Supervisor
Enclosure:
Evaluation of the Proposed Change cc: See page 3
U.S. Nuclear Regulatory Commission Page 3 April 15, 2008 Enclosure cc (Enclosure):
Mr. Brendan T. Moroney, Project Manager U.S. Nuclear Regulatory Commission Mail Stop 08G-9a One White Flint North 11555 Rockville Pike Rockville, Maryland 20852-2739 Mr. Lawrence E. Nanney, Director Division of Radiological Health Third Floor L&C Annex 401 Church Street Nashville, Tennessee 37243-1532
U.S. Nuclear Regulatory Commission Page 4 April 15, 2008 RRT:ZTK:PMB Enclosure cc (Enclosure):
AREVA NP, Inc.
P. O. Box 10935 Lynchburg, Virginia 24506-0935 ATTN: Mr. David M. Brown G. Arent, EQB 1B-WBN L. E. Nicholson, BR 4X-C W. R. Campbell, Jr., LP 3R-C C. R. Church, POB 2B-SQN J. E. Cipriani, OPS 4A-SQN T. P. Cleary, OPS 4A-SQN K. R. Jones, OPS 4A-SQN NSRB Support, BR 4X-C M. A. Purcell, BR 4X-C H. R. Rogers, LP 3R-C S. A. Vance, ET 10A-K E. J. Vigluicci, ET 10A-K WBN Site Licensing Files, ADM 1L-WBN EDMS, WT CA-K I:/License/TS Submittals/TS 08-02 Containment Purge and Isolation.doc
ENCLOSURE EVALUATION OF THE PROPOSED CHANGE
Subject:
Application for license amendment to change and realign Technical Specification (TS) 3.6.3, Containment Isolation Valves, TS 3.6.1.2, Secondary Containment Bypass Leakage, TS 3.6.1.9, Containment Ventilation System, TS 3.9.4, Containment Building Penetrations, and TS 6.8.4.h, Containment Leakage Rate Testing Program, to emulate NUREG-1431, Revision 3, Standard Technical Specification Westinghouse Plants.
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SUMMARY
DESCRIPTION This evaluation supports a request to amend Operating Licenses DPR-77 and DPR-79 for Sequoyah Nuclear Plant (SQN) Units 1 and 2.
Several changes are included within this license amendment request (LAR). Forefront in this request is a change to allow administrative control of containment purging and venting operations without obligation of cumulative time limits. This change, consistent with NUREG-1431, will be accomplished by eliminating the 1000 hour0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> per unit per year limit on containment ventilation system operation, specified in TS 3.6.1.9. Particular to this change is the elimination of the associated action and surveillance requirement (SR). This specific change is being proposed due to time limit challenges faced by operation of Unit 2 during calendar year 2007. TVA was granted a temporary TS amendment in 2007 providing 400 additional hours for Unit 2. Of the 400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br />, 300 were used for venting and purging containment. This change will provide permanent relief for the venting and purging operation that is expected to approach or surpass the current time limit once again. SQN has evaluated the elimination of the 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> against 10 CFR 50.36 criteria for inclusion into TSs, as well as elements of the Branch Technical Position 6-4 which assisted in establishing the current time limit. The evaluation provides evidence that elimination of the 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> is justified with continued protection of public health and safety. Additional changes are proposed to approach conformance with NUREG-1431. These changes include revising and relocating appropriate actions and SRs of TS 3.6.1.2 and TS 3.6.1.9 to TS 3.6.3 and TS 6.8.4.h, as necessary. The definition of Containment Integrity and TS 3.9.4 are revised for fidelity. Each proposed change hereto is detailed in the next section.
2.0 DETAILED DESCRIPTION The primary change proposed herein is to address the long-term operation of the reactor building purge ventilation (RBPV) system or more specifically the containment ventilation/purge system.
Currently, the limiting condition of operation (LCO) 3.6.1.9 for the containment ventilation system restricts operation of the system to 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> each calendar year. This limit was challenged by Unit 2 operation in 2007 due to an increased need for containment purging to limit occupational exposure of personnel to gaseous aldehyde(s). TVA in 2007 requested a license amendment to temporarily increase the time limit by 400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br />, to which NRC granted approval. This change will eliminate the 1000 hour0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> time limit from both Units 1 and 2 TSs allowing future operational flexibility without unnecessary regulatory assistance for temporary changes. Several other changes are proposed herein as an effort to conform with NUREG-1431 in regards to containment isolation.
The proposed change also includes revisions to the Containment Leakage Rate Testing Program (CLRTP), containment building penetration specification, TS index, and the TS definition of Containment Integrity.
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The following table is provided to assist in the description of the proposed change. The table provides a comparison of the current TS and the proposed change (bold indicates addition and strikethrough indicates deletion). The table also provides reference to the corresponding NUREG-1431 specification and the degree to which the proposed change is considered; Administrative, Less Restrictive, or More Restrictive.
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Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number 3.6.3 3.6.1.2 Secondary Containment Containment Bypass Leakage (SCBL),
Isolation 3.6.1.9 Containment Ventilation System (CVS), and 3.6.3 Containment Isolation Valves (CIV)
LCOs 3.6.1.2 Secondary Containment 3.6.3 Each containment isolation valve ADMINISTRATIVE bypass leakage rates shall be limited shall be OPERABLE.* 3.6.1.2 Secondary Secondary Containment operability to a combined bypass leakage rate of Containment bypass leakage rates shall is maintained by LCO 3.6.3, less than or equal to 0.25 La for all be limited to a combined bypass leakage including the modifying footnote.
penetrations that are secondary rate of less than or equal to 0.25 La for all containment BYPASS LEAKAGE penetrations that are secondary BYPASS LEAKAGE PATHS TO PATHS TO THE AUXILIARY containment BYPASS LEAKAGE PATHS THE AUXILIARY BUILDING are 1 BUILDING when pressurized to Pa.* TO THE AUXILIARY BUILDING when an integral part of Containment pressurized to Pa.* Integrity.
Enter the ACTION of LCO 3.6.1.1, "Primary Containment" when Enter the ACTION of LCO 3.6.1.1, SR 4.6.3.8 maintains leakage Secondary Containment Bypass "Primary Containment" when Secondary testing criteria with additional Leakage results in exceeding the Containment Bypass Leakage results in testing criteria and testing overall containment leakage rate exceeding the overall containment frequency maintained in the acceptance criteria. leakage rate acceptance criteria. CLRTP.
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Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number 3.6.1.9 One pair (one purge supply 3.6.3 Each containment isolation valve ADMINISTRATIVE and LESS line and one purge exhaust line) of shall be OPERABLE.* 3.6.1.9 One pair RESTRICTIVE containment purge system lines may (one purge supply line and one purge Containment purge is maintained be open; the containment purge exhaust line) of containment purge by LCO 3.6.3.
supply and exhaust isolation valves in system lines may be open; the Operability is measured by all other containment purge lines shall containment purge supply and exhaust proposed SR 4.6.3.1 which be closed. Operation with purge isolation valves in all other containment requires valves to be maintained supply or exhaust isolation valves purge lines shall be closed. Operation closed and when open limits the open for either purging or venting shall with purge supply or exhaust isolation number of open valves to two 2 be limited to less than or equal to valves open for either purging or venting paths (i.e., supply and exhaust),
1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> per 365 days. The shall be limited to less than or equal to proposed SR 4.6.3.6 which 365 day cumulative time period will 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> per 365 days. The 365 day requires leakage testing, and begin every January 1. cumulative time period will begin every proposed SR 4.6.3.7 which January 1. requires the valve be restricted from fully opening.
This proposal will eliminate the cumulative time limit. Unit 2 TS includes an additional 400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br /> for 2007, not shown here.
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Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number Actions:
A1 and A2 3.6.3 CIV 3.6.3 CIV ADMINISTRATIVE Action a. Action a.
With one or more penetration flow With one or more penetration flow paths Consistent with Standard, except paths with one containment isolation with one containment isolation valve vacuum relief isolation valve(s) valve inoperable; except for inoperable for reasons other than: which are specific to SQN containment vacuum relief isolation 1. leakage rate limits of containment valves(s), isolate each affected purge isolation valve(s),
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 2. leakage rate limit of BYPASS least one closed deactivated automatic LEAKAGE PATHS TO THE valve, closed manual valve, blind AUXILIARY BUILDING, or flange, or check valve## with flow 3. inoperable; except for containment through the valve secured; and, verify# vacuum relief isolation valves(s),
3 the affected penetration flow path is isolate each the affected penetration isolated once per 31 days for isolation 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 devices outside containment, and prior closed and deactivated automatic valve, to entering MODE 4 from MODE 5 if closed manual valve, blind flange, or not performed within the previous 92 check valve## with flow through the valve days for isolation devices inside secured; and, containment. verify# the affected penetration flow path is isolated once per 31 days for isolation devices outside containment, and prior to entering MODE 4 from MODE 5 if not performed within the previous 92 days for isolation devices inside containment.
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Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number B1 3.6.3 CIV 3.6.3 CIV ADMINISTRATIVE Action b. Action b.
With one or more penetration flow With one or more penetration flow paths paths with two containment isolation with two containment isolation valves Consistent with Standard Action, valves inoperable; except for inoperable for reasons other than: except for containment vacuum containment vacuum relief isolation 1. leakage rate limits of containment relief isolation valve(s) which are valves(s), isolate each affected purge isolation valve(s), specific to SQN and the need to penetration within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> by use of at 2. leakage rate limits of BYPASS repeat the requirement to verify least one closed deactivated automatic LEAKAGE PATHS TO THE once per 31 days.
4 valve, closed manual valve, or blind AUXILIARY BUILDING, or flange and verify# the affected 3. inoperable; except for containment penetration flow path is isolated once vacuum relief isolation valves(s),
per 31 days. isolate each the affected penetration within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> by use of at least one closed and deactivated automatic valve, closed manual valve, or blind flange and verify#
the affected penetration flow path is isolated once per 31 days.
C1 and C2 3.6.3 CIV LESS RESTRICTIVE Action f.
With one or more penetration flow SQNs Action c is specific to the paths of a closed system design with containment vacuum relief one containment isolation valve isolation valves. This proposed inoperable, isolate the affected Action does not replace Action c 5
penetration flow path within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> requirements for the containment by use of at least one closed and de- vacuum relief isolation valves; activated automatic valve, closed however, is an addition to the manual valve, or blind flange, and Actions of LCO 3.6.3. The action verify# the affected penetration is is consistent with the Standard.
isolated once per 31 days.
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Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number D1 3.6.1.2 SCBL 3.6.1.2 SCBL 3 CIV ADMINISTRATIVE With the combined bypass leakage Action d.
rate exceeding 0.25 La for BYPASS With the combined bypass leakage rate Separated restoration action from LEAKAGE PATHS TO THE exceeding 0.25 La for one or more the shutdown action.
AUXILIARY BUILDING, restore the BYPASS LEAKAGE PATHS TO THE combined bypass leakage rate from AUXILIARY BUILDING not within limit, Deleted acceptance criteria is BYPASS LEAKAGE PATHS TO THE restore the combined bypass leakage rate maintained in proposed SR 6
AUXILIARY BUILDING to less than or from BYPASS LEAKAGE PATHS TO 4.6.3.6.
equal to 0.25 La within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> or be in THE AUXILIARY BUILDING to less than at least HOT STANDBY within the or equal to 0.25 La within limit within 4 Deleted shutdown action is next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD hours or be in at least HOT STANDBY maintained in SQN LCO 3.6.3 SHUTDOWN within the following 30 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 Action g.
hours. SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. Consistent with Standard.
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Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number E1, E2 and 3.6.1.9 CVS 3.6.1.9 CVS3 CIV ADMINISTRATIVE and MORE E3 Action b. Action be. RESTRICTIVE With a containment purge supply With aone or more penetration flow and/or exhaust isolation valve having a paths with one or more containment Consistent with Standard Action.
measured leakage rate in excess of purge supply and/or exhaust isolation 0.05 La, restore the inoperable valve to valve having a measured not within OPERABLE status or isolate the leakage limits, rate in excess of 0.05 La, affected penetration flow path by use restore the inoperable valve to of at least one closed and de-activated OPERABLE status or isolate the affected automatic valve, closed manual valve, penetration flow path by use of at least or blind flange within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. one closed and de-activated automatic Verify** the affected penetration flow valve, closed manual valve, or blind path is isolated once per 31 days for flange within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Verify**# the isolation devices outside containment affected penetration flow path is isolated and prior to entering Mode 4 from once per 31 days for isolation devices 7 Mode 5 if not performed within the outside containment and prior to entering previous 92 days for isolation devices MODE 4 from MODE 5 if not performed inside containment. Otherwise be in at within the previous 92 days for isolation least HOT STANDBY within the next 6 devices inside containment. Perform SR hours and in COLD SHUTDOWN 4.6.3.6 once per 92 days for the valve within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. used to isolate the affected penetration flow path.Otherwise be in at least HOT
- Isolation devices in high radiation 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 areas may be verified by use of COLD SHUTDOWN within the following administrative means. Isolation 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
devices that are locked, sealed, or otherwise secured may be verified by ** Isolation devices in high radiation areas use of administrative means. may be verified by use of administrative means. Isolation devices that are locked, sealed, or otherwise secured may be verified by use of administrative means.
F1 and F2 3.6.3 CIV 3.6.3 CIV ADMINISTRATIVE Action d. Action dg.
With any of the above ACTIONS not With any of the above ACTIONS not met, Consistent with Standard Action 8 met, be in at least HOT STANDBY be in at least HOT STANDBY within the 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 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 SHUTDOWN within the following 30 within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
hours.
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Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number 3.6.1.9 CVS 3.6.1.9 CVS3 CIV LESS RESTRICTIVE Action a. Action a.
With a purge supply or exhaust With a purge supply or exhaust isolation Standard does not have a similar isolation valve open in excess of the valve open in excess of the above action requirement, nor does the above cumulative limit, or with more cumulative limit, or with more than one Standard have limits on the than one pair of containment purge pair of containment purge system lines number of open system lines at system lines open, close the isolation open, close the isolation valve(s) in the one time. Move restriction of one valve(s) in the purge line(s) within one purge line(s) within one hour or be in at pair of system lines open at a time 9
hour or be in at least HOT STANDBY least HOT STANDBY within the next 6 to the proposed SR.
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 hours and in COLD SHUTDOWN within SHUTDOWN within the following 30 the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. Standard Review Plan (BTP CSB hours. 6-4, Rev 2) requires limitation on the number of valves open. The limit is set at one exhaust and one intake. Standard TS does not provide such restriction.
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Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number Action Notes 3.6.3 CIV 3.6.3 CIV ADMINISTRATIVE
- 1. Penetration flow path(s) may be LCO 3.6.3 Each . . .
unisolated intermittently under -------------------- NOTES--------------------- These footnotes are relocated to administrative controls. *1. Penetration flow path(s) may be their respective location either unisolated intermittently under directly after the LCO operability
- 2. Enter the ACTION of LCO administrative controls. statement or before the Action 3.6.1.1, "Primary Containment" requirements. This is more when containment isolation 2. Enter the ACTION of LCO 3.6.1.1, consistent with the Standard.
valve leakage results in "Primary Containment" when Footnote symbols are not removed exceeding the overall containment isolation valve leakage due to the formatting of the TS.
containment leakage rate results in exceeding the overall acceptance criteria. containment leakage rate acceptance criteria.
9a ACTION:
- 3. Isolation devices in high -------------------- NOTES---------------------
radiation areas may be verified #3. Isolation devices in high radiation by use of administrative means. areas may be verified by use of administrative means.
- 4. Isolation devices that are locked, sealed, or otherwise #4. Isolation devices that are locked, secured may be verified by use sealed, or otherwise secured may of administrative means. be verified by use of administrative means.
- 5. A check valve with flow through the valve secured is only ##5. A check valve with flow through the applicable to penetration flow valve secured is only applicable to paths with two containment penetration flow paths with two isolation valves. containment isolation valves.
Surveillance Requirements SR 3.6.3.1 N/A to SQN, no 42-inch valves installed. Containment purge 10 valves are designed to close following LOCA or MSLB E1-10
Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number SR 3.6.3.2 3.6.1.9 CVS 3.6.1.9CVS3 CIV ADMINISTRATIVE SR 4.6.1.9.1 The position of the SR 4.6.1.9.13.1 The position of the containment purge supply and exhaust containmentVerify each purge supply SR consistent with Standard, isolation valves shall be determined at and/or exhaust isolation valves valve is except no valve size is specified least once per 31 days. closed, except when containment and language for one open line is purge valves (only one set of supply retained (purge supply and/or 11 and exhaust valves open) are open for exhaust isolation valve), rather pressure control, ALARA or air quality than just containment purge considerations for personnel entry, or valve.
for Surveillances that require the valves to be open, shall be determined Requirement maintains restriction at least once per 31 days. for one containment system purge line open.
3.6.1.9 CVS 3.6.1.9 CVS LESS RESTRICTIVE SR 4.6.1.9.2 The cumulative time that SR 4.6.1.9.2 The cumulative time that the the purge supply and exhaust isolation purge supply and exhaust isolation valves Standard does not have a similar 11a valves are open over a 365 day period are open over a 365 day period shall be SR.
shall be determined at least once per 7 determined at least once per 7 days.
days.
SR 3.6.3.3 No change proposed SQN SR 4.6.3.5 is consistent with 12 the Standard.
SR 3.6.3.4 No change proposed SQN SR 4.6.3.4 is consistent with 13 the Standard.
SR 3.6.3.5 No change proposed SQN SR 4.6.3.3 is consistent with 14 Standard with minor language differences.
15 SR 3.6.3.6 N/A to ice condenser plants.
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Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number SR 3.6.3.7 3.6.1.9 CVS 3.6.1.9CVS3 CIV ADMINISTRATIVE SR 4.6.1.9.3 At least once per 3 SR 4.6.1.9.3.3.6 At least once per 3 months, each containment purge months, Perform leakage rate testing SR 4.6.3.6 is consistent with the supply and exhaust isolation valve for each containment purge supply and Standard, except frequency is not shall be demonstrated OPERABLE by exhaust isolation valve shall be relaxed.
verifying that the measured leakage demonstrated OPERABLE by verifying rate is less than or equal to 0.05 La.* that the measured leakage rate is less The Standard uses the CLRTP for than or equal to 0.05 La, at least once acceptance criteria, such that per 3 months.* leakage rates exceeding these individual limits only result in the
- Enter the ACTION of LCO 3.6.1.1, containment being inoperable 16
- Enter the ACTION of LCO 3.6.1.1, "Primary Containment" when purge valve when the leakage results in "Primary Containment" when purge leakage results in exceeding the overall exceeding the overall acceptance valve leakage results in exceeding the containment leakage rate acceptance criteria. SQN must use 5%
overall containment leakage rate criteria. leakage rate criteria, so it is moved acceptance criteria. to the CLRTP. No relaxation of frequency is gained, because ASME Code testing requires testing each quarter per TS 4.0.5.
The deleted footnote is maintained by a similar note in TS 3.6.3.
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Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number SR 3.6.3.8 3.6.3 CIV 3.6.3 CIV ADMINISTRATIVE AND LESS SR 4.6.3.2 Each automatic SR 4.6.3.2 Verify each automatic RESTRICTIVE containment isolation valve shall be containment isolation valve that is not demonstrated OPERABLE at least locked, sealed or otherwise secured in SQN SR 4.6.3.2 is consistent with once per 18 months by: position, actuates to the isolation the Standard.
position on an actual or simulated
- a. Verifying that on a Phase A actuation signal, at least once per 18 Removal of a., b., and c. were containment isolation test signal, months.Each automatic containment viewed by NRC in the MERITS each Phase A isolation valve isolation valve shall be demonstrated process as removal of technical actuates to its isolation position. OPERABLE at least once per 18 months detail.
by:
- b. Verifying that on a Phase B Item 4.6.3.2.d is unique to SQN, containment isolation test signal, a. Verifying that on a Phase A added by TS Change 87-31.
each Phase B isolation valve containment isolation test signal, each actuates to its isolation position. Phase A isolation valve actuates to its Item 4.6.3.2.e is unique to SQN, isolation position. added by TS Change 88-22.
- c. Verifying that on a These were added because the Containment Ventilation isolation b. Verifying that on a Phase B valves were designated as test signal, each Containment containment isolation test signal, each containment isolation valves to 17 Ventilation Isolation valve actuates Phase B isolation valve actuates to its meet the intent of general design to its isolation position. isolation position. criteria (GDC) 55 or 56 with exemption. Actuation signals
- d. Verifying that on a high c. Verifying that on a Containment come from the solid state containment pressure isolation test Ventilation isolation test signal, each protection system (SSPS).
signal, each Containment Vacuum Containment Ventilation Isolation valve Relief Valve actuates to its isolation actuates to its isolation position.
position.
- d. Verifying that on a high
- e. Verifying that on a Safety containment pressure isolation test Injection test signal that the Normal signal, each Containment Vacuum Charging Isolation valve actuates to Relief Valve actuates to its isolation its isolation position. position.
- e. Verifying that on a Safety Injection test signal that the Normal Charging Isolation valve actuates to its isolation position.
18 SR 3.6.3.9 N/A to ice condenser plants N/A to ice condenser plants E1-13
Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number SR 3.6.3.10 3.6.3 CIV MORE RESTRICTIVE SR 4.6.3.7 Verify each containment purge valve is blocked to restrict the New SQN SR identical to valve from opening greater than or Standard. Needed in part to equal to 50 degrees, at least once per eliminate purge times limits and as 19 18 months. resolution to SRP 6.2.4.
50 degrees is used versus [50]% in the Standard. This is similar to WBN TS.
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Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number SR 3.6.3.11 3.6.1.2 SCBL 3.6.1.2SCBL3 CIV ADMINISTRATIVE SR 4.6.1.2 SR 4.6.1.23.8 The secondary containment bypass The combined secondary containment SR 4.6.1.2.a revised and becomes leakage rates shall be demonstrated: bypass leakage rates shall be SR 4.6.3.8 which is consistent to
- a. The combined bypass leakage rate demonstrated: Standard.
to the auxiliary building shall be a. The Verify the combined bypass determined to be less than or equal leakage rate for all BYPASS LEAKAGE to 0.25 La by applicable Type B and PATHS TO THE AUXILIARY BUILDING C tests in accordance with the is to the auxiliary building shall be Containment Leakage Rate Test determined to be less than or equal to program, except for penetrations 0.25 La when pressurized to greater which are not individually testable; than or equal to Pa by applicable Type B penetrations not individually and C tests in accordance with the testable shall be determined to Containment Leakage Rate Test have no detectable leakage when Programprogram, except for penetrations tested with soap bubbles while the which are not individually testable; containment is pressurized to Pa penetrations not individually testable shall (12 psig) during each Type A test. be determined to have no detectable leakage when tested with soap bubbles while the containment is pressurized to Pa 20 (12 psig) during each Type A test.
- b. Leakage from isolation valves that b. Leakage from isolation valves that are are sealed with fluid from a seal sealed with fluid from a seal system system may be excluded, subject to may be excluded, subject to the SR 4.6.1.2.b is relocated to the the provisions of Appendix J, provisions of Appendix J, Section CLRTP exception list.
Section III.C.3, when determining III.C.3, when determining the the combined leakage rate provided combined leakage rate provided the the seal system and valves are seal system and valves are pressurized to at least 1.10 Pa (13.2 pressurized to at least 1.10 Pa (13.2 psig) and the seal system capacity psig) and the seal system capacity is is adequate to maintain system adequate to maintain system pressure pressure (or fluid head for the (or fluid head for the containment containment spray system and RHR spray system and RHR spray system spray system valves at penetrations valves at penetrations 48A, 48B, 49A 48A, 48B, 49A and 49B) for at least and 49B) for at least 30 days.
30 days. SR 4.6.1.2.c is maintained in CLRTP
- c. The provisions of Specification 4.0.2 c. The provisions of Specification 4.0.2 are not applicable. are not applicable.
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Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number N/A 3/4.9.4 Containment Building 3/4.9.4 Containment Building ADMINISTRATIVE Penetrations Penetrations SR 4.9.4.b Testing the Containment SR 4.9.4.b Verifying Testing the Ventilation isolation valves per the Containment Ventilation isolation valves applicable portions of Specification not locked, sealed, or otherwise 21 4.6.3.2. secured in position, actuate to the isolation position on an actual or simulated actuation signal.per the applicable portions of Specification 4.6.3.2.
SR Notes 3.6.3 CIV 3.6.3 CIV ADMINISTRATIVE
- NOTE: Valves and blind flanges in -------------------- NOTES---------------------
high radiation areas may be verified by
- NOTE: Valves and blind flanges in high This note is relocated into the use of administrative means. radiation areas may be verified by use of beginning of the SR section. This 21a administrative means. is more consistent with the
Standard. The note symbol is not removed due to the formatting of the TS.
Index 3/4.6.1 Primary Containment 3/4.6.1 Primary Containment ADMINISTRATIVE 22 Secondary Containment Bypass Secondary Containment Bypass Leakage Leakage...............................3/4 6-2 (DELETED)...............................3/4 6-2 3/4.6.1 Primary Containment 3/4.6.1 Primary Containment ADMINISTRATIVE 23 Containment Ventilation Containment Ventilation System System...............................3/4 6-15 (DELETED)...............................3/4 6-15 E1-16
Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number Programs and Manuals 5.5.16 6.8.4 Containment Leakage Rate 6.8.4 Containment Leakage Rate Testing ADMINISTRATIVE Testing Program Program
- h. Containment Leakage Rate Testing h. Containment Leakage Rate Testing Program Program A program shall be established to A program shall be established to implement the leakage rate testing of implement the leakage rate testing of the the containment as required by 10 containment as required by 10 CFR CFR 50.54(o) and 10 CFR 50 50.54(o) and 10 CFR 50 Appendix J, Appendix J, Option B, as modified by Option B, as modified by approved approved exemptions. Visual exemptions. Visual examination and examination and testing, including test testing, including test intervals and intervals and extensions, shall be in extensions, shall be in accordance with accordance with Regulatory Guide Regulatory Guide (RG) 1.163, (RG) 1.163, "Performance-Based "Performance-Based Containment Leak-Containment Leak-Test Program," Test Program," dated September 1995 dated September 1995 with with exceptions provided in the site exceptions provided in the site implementing instructions and the 24 implementing instructions. following:. Performance of the spring Performance of the spring 2003 2003 containment integrated leakage rate containment integrated leakage rate (Type A) test may be deferred up to 5 (Type A) test may be deferred up to 5 years but no later than spring 2008.
years but no later than spring 2008. BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING leakage from isolation valves that are sealed with fluid from a seal system may be excluded, subject to the provisions of Appendix J,Section III.C.3, when determining the combined leakage rate provided the seal system and valves are pressurized to at least 1.10 Pa (13.2 psig) and the seal system capacity is adequate to maintain system pressure (or fluid head for the containment spray system and RHR spray system valves at penetrations 48A, 48B, 49A and 49B) for at least 30 days.
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Change NUREG-1431 Current SQN Technical Proposed SQN TSs Comments Item R3 (ISTS) Specifications Number 5.5.16 6.8.4 Containment Leakage Rate 6.8.4 Containment Leakage Rate Testing ADMINISTRATIVE Testing Program Program
- h. Containment Leakage Rate Testing h. Containment Leakage Rate Testing Program Program Leakage rate acceptance criteria are: Leakage rate acceptance criteria are:
- c. For each containment purge supply and exhaust isolation valve, acceptance criteria is measured leakage rate less than or equal to 0.05 La.
- d. BYPASS LEAKAGE PATHS TO THE 25 AUXILIARY BUILDING acceptance criteria are:
- 1. The combined bypass leakage rate to the auxiliary building shall be less than or equal to 0.25 La by applicable Type B and C tests.
- 2. Penetrations not individually testable shall have no detectable leakage when tested with soap bubbles while the containment is pressurized to Pa (12 psig) during each Type A test.
Definitions N/A Technical Specifications Technical Specifications ADMINISTRATIVE 1.7 CONTAINMENT INTEGRITY 1.7 CONTAINMENT INTEGRITY
- e. The sealing mechansim e. The sealing mechansim mechanism Correction of misspelling is only associated with each penetration associated with each penetration applicable to Unit 1.
(e.g., welds, bellows, or O-rings) (e.g., welds, bellows, or O-rings) is 26 is OPERABLE, and OPERABLE, and
- f. Secondary containment bypass f. Secondary containment bypass leakage is within the limits of leakage is within the limits of Specification 3.6.1.2 Specification 3.6.31.2 E1-18
LCO 3.6.1.2, Secondary Containment Bypass Leakage Changes The proposed changes associated to the dismantling of LCO 3.6.1.2, Secondary Containment Bypass Leakage include Change Item Numbers (CINs) 1, 3, 4, 6, 8, 20, 22, 24, 25, and 26. The LCO is shown as deleted in the TS index and on the LCO pages.
The LCO 3.6.1.2 operability statement is deleted and the acceptance criteria contained within is relocated. LCO 3.6.1.2 operability statement is replaced by the LCO 3.6.3 operability statement. The test pressure (Pa) is maintained and relocated to newly created SR 4.6.3.8, within LCO 3.6.3. Modes of Applicability, Modes 1, 2, 3, and 4, are maintained by LCO 3.6.3, which are identical to those in LCO 3.6.1.2. The action statement is relocated to LCO 3.6.3 and becomes Action d. The action is revised by removing the shutdown requirements and the acceptance criteria which are maintained within LCO 3.6.3 as a separate action and SR, respectively. The new action for secondary containment bypass leakage is:
- d. With one or more BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING not within limit, restore leakage within limit within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
A footnote modifies the LCO statement, which required entering action of LCO 3.6.1.1, Primary Containment, when Secondary Containment Bypass Leakage acceptance criteria exceeds the overall containment leakage rate acceptance criteria. This requirement is maintained by a similar note within LCO 3.6.3 that requires entering action of LCO 3.6.1.1 when containment isolation valve leakage exceeds the overall containment leakage rate acceptance criteria.
The SRs of LCO 3.6.1.2 are either deleted, or revised and relocated to LCO 3.6.3 and the CLRTP, as necessary. SR 4.6.1.2.a is revised and becomes SR 4.6.3.8. The changes to the SR improve consistency with NUREG-1431, such that the revised SR states:
SR 4.6.3.8 Verify the combined leakage rate for all BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING is less than or equal to 0.25 La when pressurized to greater than or equal to Pa in accordance with the Containment Leakage Rate Test Program.
Testing of the BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING penetrations is by applicable Type B and C tests. This requirement is relocated to the CLRTP. For those penetrations that were not individually testable by Type B and C tests, an exception was provided. This exception is also relocated to the CLRTP. These items are inserted under the leakage rate acceptance criteria section and read as follows:
- d. BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING acceptance criteria are:
- 1. The combined bypass leakage rate to the auxiliary building shall be less than or equal to 0.25 La by applicable Type B and C tests.
- 2. Penetrations not individually testable shall have no detectable leakage when tested with soap bubbles while the containment is pressurized to Pa (12 psig) during each Type A test.
Another exception is provided for in SR 4.6.1.2.b. This exception provides exemption from E1-19
determining the leakage rates of isolation valves that are sealed with fluid from a seal system subject to the provisions of 10 CFR 50 Appendix J, Section III.C.3, yet, this exception is relocated to the CLRTP. SR 4.6.1.2.c is deleted. This exclusion from applying SR 4.0.2 is maintained by the CLRTP.
LCO 3.6.1.9, Containment Ventilation System Changes The proposed changes associated to the dismantling of LCO 3.6.1.9, Containment Ventilation System include CINs 2, 3, 4, 7, 8, 9, 11, 11a, 16, 19, 23, and 25. The LCO is shown as deleted in the TS index and on the LCO pages. The LCO 3.6.1.9 operability statement is deleted and replaced by the LCO operability statement of 3.6.3. The requirement of LCO 3.6.1.9 to maintain all but one pair of containment purge system lines closed during operation is relocated to SR 4.6.3.1 that states:
4.6.3.1 Verify each purge supply and/or exhaust isolation valve is closed, except when the containment purge valves are open (only one set of supply and exhaust valves open) for pressure control, ALARA or air quality considerations for personnel entry, or for Surveillances that require the valves to be open, at least once per 31 days.
Modes of Applicability, Modes 1, 2, 3, and 4, are maintained by LCO 3.6.3 which are identical to those in LCO 3.6.1.9.
Action a, which contained requirements to isolate the purge system lines within one hour if the cumulative time limit had been exceeded or if more than one purge system line was open otherwise enter into shutdown requirements, is deleted. Action b which provides response to purge valves measured leakage rates is revised and relocated to TS 3.6.3 as Action e. The action statement becomes:
- e. With one or more penetration flow paths with one or more containment purge supply and/or exhaust isolation valves not within leakage limits, isolate the affected penetration flow path by use of at least one closed and de-activated automatic valve, closed manual valve, or blind flange within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Verify# the affected penetration flow path is isolated once per 31 days for isolation devices outside containment and prior to entering MODE 4 from MODE 5 if not performed within the previous 92 days for isolation devices inside containment. Perform SR 4.6.3.6 once per 92 days for the valve used to isolate the affected penetration flow path.
A measured leakage rate acceptance criteria limit of 5 percent La was contained in Action b, but is not maintained in Action e. Action b of LCO 3.6.1.9 is modified by a footnote identified by double asterisks (**). The action footnote allows for verification of isolated devices in high radiation areas and devised locked, sealed, or otherwise secured by administrative means. This footnote is provided in LCO 3.6.3, yet the note symbol is changed from double asterisks (**) to a pound symbol (#). Shutdown requirements deleted from this action are maintained by the final LCO 3.6.3 Action. An action to perform SR 4.6.3.6, leakage rate testing, is added for the valve used to isolate the affected penetration flow path. Specific to Unit 2 LCO 3.6.1.9 is a temporary extension of 400 cumulative hours for ventilation system operation. This extension is deleted.
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SR 4.6.1.9.1 which requires position verification of the purge isolation valves once per 31 days is revised and relocated to LCO 3.6.3 as SR 4.6.3.1, as discussed above.
SR 4.6.1.9.2 which requires cumulative time tracking of open purge isolation valves is deleted. SR 4.6.1.9.3 which requires leakage rate testing is revised and relocated to LCO 3.6.3 as SR 4.6.3.6. The new SR 4.6.3.6 is modified to be consistent with NUREG-1431, except the testing frequency is maintained at once per 3 months rather than relaxing the normal periodic testing for the purge system valves by 92 days and adding conditional testing of cycled valves within 92 days after opening. The leakage rate acceptance criteria of 5 percent La is removed from the SR and relocated to the CLRTP. SR 4.6.1.9.3 is modified by a footnote to enter the action of LCO 3.6.1.1 in the event that purge valve leakage results exceed the overall containment leakage rate acceptance criteria. This modification of the SR is maintained under LCO 3.6.3 by an existing footnote that applies to all containment isolation valves. The new SR 4.6.3.6 is written as:
4.6.3.6 Perform leakage rate testing for each containment purge supply and exhaust isolation valve at least once per 3 months.
A new SR is implemented to verify the containment purge valves are blocked to restrict its opening to 50 degrees. This SR is written as:
4.6.3.7 Verify each containment purge valve is blocked to restrict the valve from opening greater than or equal to 50 degrees, at least once per 18 months.
LCO 3.6.3, Containment Isolation Valves Changes Several changes are associated with the accumulation of containment isolation valves requirements within LCO 3.6.3, Containment Isolation Valves, and include CINs 1, 2, 3, 4, 5, 6, 7, 8, 9a, 10, 11, 12, 13, 14, 15, 16, 17, 19, 20, 21, 21a, 24, 25, and 26. LCO 3.6.3, Actions a and b are modified to include exception statements for leakage rate limits of specific components and modified for ease of use. This statement is added to the actions:
for reasons other than leakage rate limits of containment purge isolation valve(s) and BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING Actions a and b are written as follows, respectively:
- a. With one or more penetration flow paths with one containment isolation valve inoperable for reasons other than:
- 1. leakage rate limits of containment purge isolation valve(s),
- 2. leakage rate limit of BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING, or
- 3. inoperable containment vacuum relief isolation valves(s),
isolate the 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 and deactivated automatic valve, closed manual valve, blind flange, or check valve## with flow through the valve secured; and, verify# the affected penetration flow path is isolated once per 31 days for isolation devices outside containment, and prior to entering MODE 4 from MODE 5 if not performed within the previous 92 days for isolation devices inside containment.
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- b. With one or more penetration flow paths with two containment isolation valves inoperable for reasons other than:
- 1. leakage rate limits of containment purge isolation valve(s),
- 2. leakage rate limit of BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING, or
- 3. inoperable containment vacuum relief isolation valves(s),
isolate the affected penetration within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> by use of at least one closed and deactivated automatic valve, closed manual valve, or blind flange and verify# the affected penetration flow path is isolated once per 31 days.
Within the actions, the pronoun each is replaced with the between the words isolate and affected. Also the conjunction and is inserted between closed and deactivated.
A new action statement, Action f, is implemented which is specific to closed systems. This action is written as:
- f. With one or more penetration flow paths of a closed system design with one containment isolation valve inoperable, isolate the affected penetration flow path within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> by use of at least one closed and de-activated automatic valve, closed manual valve, or blind flange, and verify# the affected penetration is isolated once per 31 days.
The conditional periodic verification of Action f is modified by a note, denoted by note symbol #. The note consists of two provisions: 1) applies to valves and blind flanges located in high radiation areas and allows these devices to be verified closed by use of administrative means; and 2) applies to isolation devices that are locked, sealed, or otherwise secured in position and allows these devices to be verified closed by use of administrative means.
To allow for insertion of Actions d, e, and f discussed above, the current Action d which contains the shutdown requirements is revised to be Action g.
To accommodate the changes and current formatting of the TS, the footnotes are relocated to their respective location more conforming to NUREG-1431. The footnotes #1 and 2 which modify the LCO Operability statement are relocated underneath the statement. The action modifying footnotes #3, #4, and ##5 are relocated to the beginning of the Action section. The footnote symbols are not deleted. The footnotes or notes text is preceded and followed by dashed lines that extend the full length of the text. The word NOTES appears in the center of the top dashed line.
SR 4.6.3.1 currently shown as deleted is replaced with the new SR 4.6.3.1 discussed above. The other SRs, 4.6.3.6 and 4.6.3.7 are inserted after 4.6.3.5. A change is proposed to SR 4.6.3.2 that would replace the current language with that contained in NUREG-1431 for verification of automatic containment isolation valve testing to ensure closure of valves upon actual or simulated actuation signals. The SR would be written as:
Verify each automatic containment isolation valve that is not locked, sealed or otherwise secured in position, actuates to the isolation position on an actual or simulated actuation signal, at least once per 18 months.
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An exception to verifying actuation of a valve that is not locked, sealed, or otherwise secured in position is provided. This exception is new and is not in the current SR 4.6.3.2.
To accommodate the surveillance changes and current formatting of the TS, the one SR NOTE is relocated to the beginning of the SR section. The footnote symbol is not deleted.
The footnote or note text is preceded and followed by dashed lines that extend the full length of the text. The word NOTE appears in the center of the top dashed line.
LCO 3.9.4, Containment Building Penetrations Changes For consistency with the proposed change to SR 4.6.3.2, SR 4.9.4.b is revised by deleting the leading word Testing and the phrase per the applicable portions of Specification 4.6.3.2 and adding the actual required intent of Specification 4.6.3.2 such that the SR is written as:
- b. Verifying the Containment Ventilation isolation valves not locked, sealed, or otherwise secured in position, actuate to the isolation position on an actual or simulated actuation signal.
TS 6.8.4.h, Containment Leakage Rate Testing Program Changes Unit 1 TS 6.8.4.h has a provision for containment integrated leakage rate (Type A) test to be deferred up to 5 years from spring 2003 but no later than spring 2008. Unit 2 has a similar provision although the deferral ended spring 2007. It is proposed that these provisions be deleted. It is also proposed that the last sentence in the first paragraph be revised by including the conjunctional phrase, and the following:. This change supports the following discussion.
The SRs of LCO 3.6.1.2 provided alternate leakage method acceptance criteria for the secondary containment bypass leakage paths. The first within SR 4.6.1.2.a provides an acceptance criterion to penetrations which are not individually testable under 10 CFR 50 Appendix J, Test B and C. The second acceptance criterion within SR 4.6.1.2.b provides exclusion from testing of isolation valves that are sealed with fluid from a seal system subject to the provisions of §CFR50 Appendix J,Section III.C.3. These criteria are moved to TS 6.8.4.h. One criterion follows the first paragraph of the section and reads as follows:
. . . instructions and the following:
BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING leakage from isolation valves that are sealed with fluid from a seal system may be excluded, subject to the provisions of Appendix J,Section III.C.3, when determining the combined leakage rate provided the seal system and valves are pressurized to at least 1.10 Pa (13.2 psig) and the seal system capacity is adequate to maintain system pressure (or fluid head for the containment spray system and RHR spray system valves at penetrations 48A, 48B, 49A and 49B) for at least 30 days.
The other criterion is inserted, as d.2, under the section starting with Leakage rate acceptance criteria are:
- d. BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING acceptance criteria are:
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- 1. The combined bypass leakage rate to the auxiliary building shall be less than or equal to 0.25 La by applicable Type B and C tests.
- 2. Penetrations not individually testable shall have no detectable leakage when tested with soap bubbles while the containment is pressurized to Pa (12 psig) during each Type A test.
The acceptance criteria for those penetrations tested by applicable Type B and C tests is also located here as shown above.
As mentioned previously, the leakage rate acceptance criterion in SR 4.6.1.9.3 for the containment purge valves is also moved to this section. The acceptance criterion is written as follows:
- c. For each containment purge supply and exhaust isolation valve, acceptance criteria is measured leakage rate less than or equal to 0.05 La.
Definitions Changes Item f in the definition of CONTAINMENT INTEGRITY is revised for fidelity. This is accomplished by revising the reference of TS 3.6.1.2 to TS 3.6.3. Additionally, in Unit 1s definition a misspelling of the word mechanism is corrected.
3.0 TECHNICAL EVALUATION
The Reactor Building Purge Ventilating (RBPV) system is designed to maintain the environment in the primary and secondary containment within acceptable limits for equipment operation and for personnel access during inspection, testing, maintenance, and refueling operations, and to limit the release of radioactivity to the environment. The RBPV system is described in Section 9.4.7 of the Updated Final Safety Analysis Report (UFSAR).
The design basis includes the provisions to:
- 1. Supply fresh air for breathing and contamination control when the primary or annulus secondary containment is or will be occupied.
- 2. Exhaust primary or annulus secondary containment air to the outdoors whenever the purge air supply system is operated.
- 3. Cleanup containment exhaust by routing the air through HEPA-charcoal filter trains before release to the atmosphere.
- 4. Provide a reduced quantity of ventilating air to permit occupancy of the instrument room during reactor operation. The provisions for 1, 2, and 3 above will apply.
- 5. Ensure an unimpeded closure of the containment isolation valves installed in the system penetrations on a containment ventilation isolation (CVI) signal.
One complete and independent RBPV system is provided for each unit. The RBPV E1-24
system provides for mechanical ventilation of the primary containment, the instrument room located within the containment, and the annulus secondary containment located between the containment and shield building. The system is designed to supply fresh air for breathing, and contamination control to allow personnel access for maintenance and refueling operations. The exhaust air is filtered to limit the release of radioactivity to the environment.
Each purge system containment penetration is provided with both inboard and outboard air-operated isolation butterfly valves designed for minimum leakage in their closed position. A similar type of valve is mounted in each purge supply and exhaust air opening for the annulus, and in each of the systems main supply and exhaust duct located exterior to the shield building. Each of the above butterfly valves is designed to fail closed and to be normally closed during purge system shutdown.
The containment purge penetrations are safety-related in that they must not jeopardize the integrity of the containment boundary. These penetrations are designed to withstand (with essentially zero leakage) the forces produced by a loss-of-coolant accident (LOCA), or a main steam line break (MSLB). The penetrations are provided with an isolation mechanism which is activated by the initiation of the CVI signal. The isolation mechanism has 100 percent redundancy in both equipment and power sources. The system is also isolated upon detection of high radiation in the purge exhaust.
The primary containment is designed to assure that an acceptable upper limit of leakage of radioactive material is not exceeded under design basis accident conditions. The secondary containment system was designed to assure that an effective barrier will exist for airborne fission products that may leak from the primary containment during a LOCA.
Within the scope of the design exists requirements that influence the size, structural integrity, and leak tightness of the secondary containment enclosure. Specifically, these include a capability to: (a) Maintain an effective barrier for gases and vapors that may leak from the primary containment during all normal and abnormal events; (b) Delay the release of any gases and vapors that may leak from the primary containment during a LOCA; (c) Allow gases and vapors that may leak through the primary containment during a LOCA to flow into the contained air volume within the secondary containment where it will be diluted, held up, and filtered prior to being released to the environs; (d) Bleed to the annulus secondary containment each air-filled containment penetration enclosure which extends beyond the shield building and that is formed by automatically actuated isolation valves; and (e) Maintain an effective barrier for airborne radioactive contaminants, gases and vapors originating in the auxiliary building during all normal and abnormal events.
Additional, information for the primary and secondary containment systems can be found in Section 6.2.1 of the UFSAR.
The safety design basis for containment leakage assumes that 75 percent of the leakage from the primary containment enters the shield building annulus for filtration of the emergency gas treatment system. The remaining 25 percent of the primary containment leakage, which is considered to be bypassed to the auxiliary building, is assumed to exhaust directly to the atmosphere without filtration during the first 5 minutes of the accident. After 5 minutes, any bypass leakage to the auxiliary building is filtered by the auxiliary building gas treatment system. A tabulation of potential secondary containment bypass leakage paths to the auxiliary building is provided in the SQNs system description documents for containment isolation. Restricting the leakage through the bypass leakage paths to 25 percent of the maximum allowable containment leakage rate at the calculated peak containment internal pressure provides assurance that the leakage fraction E1-25
assumptions used in the evaluation of site boundary radiation doses remain valid.
The purpose of containment isolation is to provide positive closure methods in lines penetrating primary containment in the event of a LOCA within containment or another event that creates one of the containment isolation signals. The containment isolation (CI) systems provide the means of isolating fluid systems that pass through containment penetrations so as to confine to the containment any radioactivity that may be released in the containment following a design basis event (DBE). The CI systems are required to function following a DBE to isolate applicable fluid systems penetrating the containment.
The objective of containment isolation is to allow the normal or emergency passage of the following while preserving the integrity of the containment boundary: Engineered Safety Feature (ESF) system fluids, or fluid of systems which are not required to function following a LOCA but, if available, can be used to accomplish a function similar to an engineered safety feature system. Other fluid systems shall be isolated upon the appropriate isolation signal. Isolation design is achieved by applying common criteria to penetrations in many different fluid systems and by using ESF signals to actuate appropriate valves. The following design criteria apply to the CI systems.
- 1. The design pressure of all piping and connected equipment comprising the isolated boundary is equal to or greater than the design pressure of the containment.
- 2. All valves and equipment which are considered to be isolation barriers are designed in accordance with seismic Category I criteria and are protected against missiles and jets, both inside and outside the containment.
- 3. A system is closed outside the containment if it meets all of the following:
- a. It does not communicate with the atmosphere outside the containment.
- b. Its safety class is the same as for engineered safety systems.
- c. Its internal design pressure and temperature are greater than or equal to containment design pressure and temperature.
- d. It is missile and jet protected.
- e. Withstand LOCA transients and environment.
- 4. A system is closed inside the containment if it meets all of the following:
- a. It does not communicate with either the reactor coolant system or the reactor containment atmosphere.
- b. Its safety class is the same as for engineered safety systems.
- c. It will withstand external pressure and temperature equal to containment design pressure and temperature.
- d. It will withstand accident temperature, pressure, and fluid velocity transients, and the resulting environment, including internal thermal expansion.
- e. It is missile and jet protected.
Systems not completely meeting the requirements of Criteria 3 or 4 are considered open systems.
- 5. A check valve inside the containment on the incoming line is considered an automatic isolation valve.
- 6. A pressure-relief valve that relieves toward the inside of the containment is considered an automatic isolation valve.
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- 7. A locked closed valve may be used for isolating containment, and does not require any additional operator action.
- 8. To qualify as an automatic isolation valve, a power-operated valve must fail in the position to provide the greatest safety control on loss of air, power, etc.
- 9. All valves used for containment isolation will be capable of tight shutoff against gas leakage from containment design pressure down to approximately 12 pounds per square inch gauge (psig).
- 10. Remote-manual valves may be used for isolation provisions associated with engineered safety features (such as the emergency core cooling system [ECCS])
instead of automatic isolation valves.
The design basis for the CI systems includes provision for the following:
- 1. A double barrier at the containment penetration in those fluid systems that are not required to function following a DBE.
- 2. Automatic, fast, efficient closure of those valves required to close for containment integrity following a DBE to minimize release of any radioactive material.
- 3. A means of leak-testing barriers in fluid systems that serve as containment isolation unless leak testing is specifically exempt based on Appendix J or an approved exemption.
- 4. The capability to periodically test the operability of containment isolation valves.
Further information regarding containment isolation systems is found in UFSAR Section 6.2.4.
3.1 ADMINISTRATIVE CHANGES Several of the proposed changes result in a redistribution or realignment of the requirements consistent with NUREG-1431. These changes do not result in a technical requirement relaxations or additional restrictions. The majority of these changes are proposed to bring SQN TSs in greater conformance with NUREG-1431. The balance of the changes is necessary for fidelity.
Administrative Changes to LCO 3.6.1.2 Changes associated with LCO 3.6.1.2 include CINs 1, 3, 4, 6, 8, 20, 22, 24, 25, and 26.
Each of these changes is considered administrative in nature because no reduction in or extension of requirements is sought.
LCO 3.6.1.2 requires secondary containment bypass leakage rates to be within the prescribed limit in Modes 1, 2, 3, and 4. CIN 1 deletes the LCO 3.6.1.2 operability statement. The operability of the secondary containment BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING will be maintained within LCO 3.6.3, which requires each containment isolation valve to be operable in Modes 1, 2, 3, and 4. The current operability statement in LCO 3.6.3 is consistent with NUREG-1431. The requirements to maintain operability involve SR 4.6.1.2 which is changed by CIN 20 to revise and relocate the E1-27
portions of SR 4.6.1.2 to SR 4.6.3.8. The portion that is revised and relocated to SR 4.6.3.8 is consistent with the language in NUREG-1431 SR 3.6.3.11, except that BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING is used in place of shield building bypass leakage paths. The balance of SR 4.6.1.2 is relocated to TS 6.8.4.h by CINs 24 and 25. The revision and relocation of SR 4.6.1.2 does not change any technical requirement necessary to establish operability of the secondary containment bypass. The revision and relocation of SR 4.6.1.2 does not grant use of SR 4.0.2 for extension of a SR frequency, because TS 6.8.4.h contains a statement that prohibits the application of SR 4.0.2 to test frequencies in the CLRTP.
Action requirements of LCO 3.6.1.2 are revised and relocated to LCO 3.6.3 Actions d and g, under CINs 6 and 8. This change revises LCO 3.6.1.2 action to be consistent with NUREG-1431 Actions D and F. The action to restore the leakage limit of BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> is maintained and is consistent with the NUREG-1431. An inability to restore the leakage limit within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> requires entering into shutdown requirements. This action is maintained by LCO 3.6.3 Action g, which is revised to be the end action by CIN 8. Changes made to LCO 3.6.1.2 action requirements are consistent with current SQN LCO requirements and those found in NUREG-1431.
To support induction of LCO 3.6.1.2 into LCO 3.6.3, CINs 3 and 4 are necessary. These changes add an exclusion statement to LCO 3.6.3 Actions a and b that exempt the BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING from closure for excessive leakage rates. This change is consistent with NUREG-1431 and provides no additional relaxation. The action to take in the event of excessive leakage, defined by SR 4.6.3.8, is given in LCO 3.6.3 Action d. CINs 3 and 4 also restructures Actions a and b to provide clearer understanding of the required actions.
The index is revised by CIN 22 to show that LCO 3.6.1.2 is deleted.
The definition of Containment Integrity in part requires secondary containment bypass leakage to be within limits by SR 4.6.1.2. The definition is revised by CIN 26 for fidelity to refer to SR 4.6.3.8. The Unit 1 definition includes a misspelling of the word mechanism.
This is correct by CIN 26.
Administrative Changes to LCO 3.6.1.9 Administrative changes associated with LCO 3.6.1.9 include CINs 3, 4, 7, 8, 11, 16, 23, and 25. In part, CINs 2 and 7 are also administrative. Each of these changes are considered administrative in nature because no reduction in or extension of requirements is sought.
Currently, LCO 3.6.1.9 allows only one pair of containment purge system lines to be open at a time. The opening of the purge system lines is also limited to a specified amount of time each calendar year in Modes 1, 2, 3, and 4. CIN 2 deletes the LCO 3.6.1.9 operability statement which is replaced by LCO 3.6.3s statement. The operability of the containment purge lines, or more specific, containment purge valves will be maintained within LCO 3.6.3, which requires each CIV to be operable in Modes 1, 2, 3, and 4. The requirements to demonstrate operability are contained in LCO 3.6.1.9 operability E1-28
statement, SRs 4.6.1.9.1, 4.6.1.9.2, and 4.6.1.9.3. The proposed change to eliminate the cumulative time limit and tracking surveillance of LCO 3.6.1.9 is less restrictive and will be discussed in more detail in the section for Less Restrictive Changes. The SQN operability statement in LCO 3.6.3 is consistent with NUREG-1431.
In part, to show operability of the containment purge valves, SR 4.6.1.9.1 is revised and relocated to SR 4.6.3.1 by CIN 11. The revision of SR 4.6.1.9.1 is made to be consistent with NUREG-1431 SR 3.6.3.2. NUREG-1431 SR 3.6.3.2 requires each purge valve to remain closed when not open for pressure control, ALARA or air quality considerations for personnel entry or surveillances. The NUREG-1431 SR is different than SQN SR in that SR 4.6.1.9.1 requires a verification of the valves position with time tracking for open valves required by SR 4.6.1.9.2. However, SQN does not allow its purge lines to be opened imprudently, without procedural guidance and reason for operation, nor for reasons other then stated in NUREG-1431. Therefore, applying NUREG-1431 SR 3.6.3.2 is not operationally different and would be administrative. A difference is noted in regards to the number of lines that can be opened at once. The NUREG does not limit the number of purge valves that can be opened during LCO applicability; however, to maintain our current accident analysis assumptions and remain within the 10 CFR 100 values, only one purge system line (supply and exhaust) containing 24-inch valves is allowed to be open at the start of the event. This requirement was established in Branch Technical Position CSB 6-4, July 1981. To accomplish this, SR 4.6.3.1 is modified from the language of NUREG-1431 SR 3.6.3.2 to include the following text indicated by bolds characters:
4.6.3.1 Verify each purge supply and/or exhaust isolation valve is closed, except when the containment purge valves are open (only one set of supply and exhaust valves open) for pressure control, ALARA or air quality considerations for personnel entry, or for Surveillances that require the valves to be open, at least once per 31 days.
This modification does not result in a new requirement and is within our normal system operation. Two other SRs are necessary to support the determination of purge valve operability. These include leakage testing and verification of valve blocks to restrict full open. CINs 16 and 19 identify these proposed changes. CIN 19 establishes a new SR for SQN that is more restrictive, therefore is discussed in the section for More Restrictive Changes.
CIN 16 involves the revision and relocation of leakage rate testing of SR 4.6.1.9.3 to SR 4.6.3.6. The SR is revised for consistency with NUREG-1431 SR 3.6.3.7, except TVA does not propose to relax the testing frequency to 184 days or add a conditional test upon cycling the valves. The change requires the specific maximum leakage rate of 5 percent of the total containment leakage rate (La) for each of these valves to be relocated to the TS 6.8.4.h CLRTP. The inclusion of the specific purge valve leakage rate acceptance criterion to the CLRTP is provided by CIN 25.
A footnote modifies SR 4.6.1.9.3. This footnote required the application of the action in LCO 3.6.1.1 if the containment purge valve leakage results exceed the overall containment leakage rate acceptance criteria. CIN 16 also deletes the footnote and footnote symbol. However, the LCO 3.6.3 operability statement is modified by a footnote with a similar requirement. The footnote requires the application of the action in LCO 3.6.1.1 when a containment isolation valve leakage results exceed the overall containment leakage rate acceptance criteria. Containment purge valves are CIVs; therefore, the minor wording difference is administrative.
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Action b of LCO 3.6.1.9 is revised and relocated to LCO 3.6.3 Action e by CIN 7. This change revises LCO 3.6.1.9 Action b to be consistent with NUREG-1431 Action E. The action to restore the inoperable valve within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or isolate the affected penetration flow path by acceptable means is maintained and is consistent with the NUREG-1431.
Verification of the isolated penetration once per 31 days and prior to entering Mode 4 from Mode 5 is also maintained. An inability to complete these actions requires entering into shutdown requirements. LCO 3.6.3 Action f, which is revised to be the last action by CIN 8 maintains the shutdown requirements. Verification of isolated penetrations is permitted by administrative means for isolation devices in high radiation areas and for isolation devices that are locked, sealed, or otherwise secured as denoted by the footnote.
CIN 7 revises the footnote symbol, within the action statement, to a pound symbol (i.e., #).
Identical action modifying footnotes allowing verification of isolation devices by administrative means are provided in LCO 3.6.3, which are recognized by a single pound symbol. An action requirement to perform SR 4.6.3.6, containment purge valve leakage test, is added. This addition is more restrictive and will be discussed in more detail in the section for More Restrictive Changes.
To support induction of LCO 3.6.1.9 into LCO 3.6.3, CINs 3 and 4 are necessary. These changes add an exclusion statement to LCO 3.6.3 Actions a and b that exempt the containment purge isolation valve(s) from closure for excessive leakage rates. This change is consistent with NUREG-1431 and provides no additional relaxation. The action to take in the event of excessive leakage defined by SR 4.6.3.6 is given in LCO 3.6.3 Action e. CINs 3 and 4 also restructures Actions a and b to provide clearer understanding of the required actions.
The Index is revised by CIN 23 to show that LCO 3.6.1.9 is deleted.
The revision and relocation of SR 4.6.1.9.3 does not change any technical requirement (i.e., leakage rate acceptance criteria) necessary to establish operability of the containment purge valves. The revision and relocation of SR 4.6.1.9.3 to SR 4.6.3.6 does not change the leakage rate testing frequency.
Administrative Changes to LCO 3.6.3 Administrative changes associated with LCO 3.6.3 include CINs 3, 4, 6, 7, 8, 9a, 11, 16, 17, 20 and 21a. The majority of the CINs have been discussed in detail in the above sections. A few minor details are discussed hereafter. As part of changes to LCO 3.6.3 Actions a and b, CINs 3 and 4 also replaces the pronoun each with the between the words isolate and affected. Also the conjunction and is inserted between closed and deactivated. These editorial changes make the action statements more consistent with NUREG-1431.
CINs 6 and 7 insert action requirements in LCO 3.6.3 for BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING and a containment purge valve if inoperable, respectively.
To maintain a progressive action flow, CIN 8 is necessary. CIN 8 changes LCO 3.6.3 Action d to Action g allowing CINs 6 and 7 to be placed prior to the shutdown action. This change is editorial and consistent with NUREG-1431.
CIN 11 replaces the current SR 4.6.3.1 shown as deleted with revised SR 4.6.1.9.1. This deletion of the word Deleted is administrative.
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CINs 16 and 20 will add SRs to LCO 3.6.3. The insertion of the SRs creates new SR numbers and is administrative in nature.
CIN 17 includes both a less restrictive change and administrative change. The less restrictive change will be discussed in more detail in the section for Less Restrictive Changes. The administrative change include the clarification that valves which are locked, sealed, or otherwise secured in their required safety position, are not required to be tested. The proposed change also clarifies that an actual, as well as a simulated test signal, may be used to meet the SR. This change clarifies that credit may be taken for unplanned actuation to satisfy the SRs, if sufficient information is collected. Actual initiation of a safety device is as good, or better, for meeting testing requirements as a simulated initiation. The proposed requirement does not change the technical content or validity of the required testing.
CINs 9a and 21a relocate specific footnotes or note(s) related to the action and SR statements, respectively. These modifying notes are moved to the beginning of their respective section and are clearly identified as Notes consistent with TSs writers guide.
This change is made to accommodate the formatting of the TSs; resolve the use of a similar note symbol with different modifiers within the TS pages; and is more consistent with NUREG-1431. The footnote symbols are not removed, thereby continuing to provide easy user understanding of the modification.
Each of the above changes is considered administrative in nature because no reduction in or extension of technical requirements is proposed. These changes retain the technical requirements and are consistent with NUREG-1431.
Administrative Changes to LCO 3.9.4 CINs 17 and 21 are associated with the elimination of excessive detail SR 4.6.3.2. CIN 17 proposed to revise SR 4.6.3.2 to match NUREG-1431 SR 3.6.3.8. This particular change is less restrictive and will be discussed in more detail in the section for Less Restrictive Changes. CIN 21 revises SR 4.9.4.b, which requires testing the containment ventilation isolation valves per the applicable portions of [emphasis added] Specification 4.6.3.2.
Because CIN 17 eliminates the technical detail of each different isolation valve and associated test signal verification actuation, SR 4.9.4.b needs to specify the actual requirement to be performed on containment ventilation valves. This is accomplished by revising SR 4.9.4.b to accept the actual requirement such that the SR is written as:
Verifying the Containment Ventilation isolation valves not locked, sealed, or otherwise secured in position, actuate to the isolation position on an actual or simulated actuation signal.
This change is considered administrative in that no relaxation of a technical requirement is proposed and is more consistent with NUREG-1431 SR 3.9.4.2.
Administrative Changes to TS 6.8.4.h CINs 16, 20, 24, and 25 include administrative changes to the CLRTP to which each CIN is discussed in some detail above.
The revision by CIN 16 results in the SR 4.6.1.9.3 for containment purge valve leakage rate testing to be relocated to SR 4.6.3.6 consistent with NUREG-1431. The leakage rate E1-31
acceptance criteria of 5 percent of the total containment leakage rate (La) for each of these valves however is relocated to the CLRTP. This change is accomplished by CIN 25 where the following statement is added under the section for leakage rate acceptance criteria:
- c. For each containment purge supply and exhaust isolation valve, acceptance criteria is measured leakage rate less than or equal to 0.05 La.
This relocation of containment purge valve leakage rate acceptance criterion does not change the specific leakage rate value for each containment purge valve and is considered an administrative change.
CIN 20 changes SR 4.6.1.2, regarding secondary containment bypass testing, to SR 4.6.3.8. However, only a portion of the entire SR is relocated to SR 4.6.3.8 assuring consistency to NUREG-1431. CINs 24 and 25 change the CLRTP in part to insert an exception to secondary containment leakage testing and insert the leakage rate acceptance criteria for secondary containment leakage paths that are removed from SR 4.6.1.2. This relocation of test exceptions and result limits is administrative.
CIN 24 also deletes a previously approved exception regarding performance of containment integrated leakage rate testing. Specifically, the provision Performance of the spring 2003 containment integrated leakage rate (Type A) test may be deferred up to 5 years but no later than spring 2008.
for Unit 1 is deleted. This provision will no longer be effective in June 2008, and more so the deferral is no longer necessary because integrated containment testing (Type A) was performed during the fall 2007, Unit 1 Cycle 15 refueling outage. Unit 2 has a similar provision, Performance of the spring 2003 containment integrated leakage rate (Type A) test may be deferred to no later than spring 2007.
which has lapsed. Integrated leakage rate testing was performed during the fall 2006, Unit 2 Cycle 14 refueling outage. The deletion of the above provisions is administrative in that it removes requirement no longer necessary.
The secondary containment leakage exception, removed from SR 4.6.1.2.a, is added to the first paragraph of TS 6.8.4.h including the text and the following, such that paragraph is written as:
. . . instructions and the following:
BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING leakage from isolation valves that are sealed with fluid from a seal system may be excluded, subject to the provisions of Appendix J,Section III.C.3, when determining the combined leakage rate provided the seal system and valves are pressurized to at least 1.10 Pa (13.2 psig) and the seal system capacity is adequate to maintain system pressure (or fluid head for the containment spray system and RHR spray system valves at penetrations 48A, 48B, 49A and 49B) for at least 30 days.
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The changes presented in CIN 24 do not result in addition or relaxation of requirements for secondary containment bypass or the containment integrated leakage rate test. These changes are administrative and necessary for conformance with NUREG-1431.
The leakage rate acceptance criterion for the secondary containment bypass removed by CIN 20, is relocated to the CLRTP similar to the containment purge valve acceptance criterion under CIN 25. Specifically, the criterion is inserted following the containment purge valve acceptance criterion as follows:
- d. BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING acceptance criteria are:
- 1. The combined bypass leakage rate to the auxiliary building shall be less than or equal to 0.25 La by applicable Type B and C tests.
- 2. Penetrations not individually testable shall have no detectable leakage when tested with soap bubbles while the containment is pressurized to Pa (12 psig) during each Type A test.
Once again, the changes presented in CIN 25 do not result in addition or relaxation of requirements for secondary containment bypass leakage rate test. These changes are administrative and conform to NUREG-1431.
3.2 LESS RESTRICTIVE CHANGES Changes discussed in this section are considered Less Restrictive because the changes result in removal of technical details, action requirements, and surveillances. These changes provide consistency with NUREG-1431. The following proposed changes are identified by CINs 2, 5, 9, 11a, and 17.
Less Restrictive Change to LCO 3.6.1.9 The primary request of this LAR is removal of the time limit that restricts opening of a containment purge valve during a calendar year beginning on January 1st to less than 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br />. TVA had by References 1 and 2 requested in 1981, the time limit be elevated from 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br /> to 2440 hours0.0282 days <br />0.678 hours <br />0.00403 weeks <br />9.2842e-4 months <br /> to support operation of Unit 1. NRC approved the LAR by Reference 3, yet restricted the time limit to 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> pending further information. TVA provided this information by Reference 4. SQN has operated each unit within the 1000-hour time limit since the early 1980s until recently. TVA by Reference 5 requested a temporary extension for 400 additional purge hours for Unit 2 operations in 2007, to which NRC granted an amendment by Reference 6. The recent amendment was necessary for better air quality inside containment for personnel safety during containment entry and continued operation of Unit 2. The increase in containment ventilation has been attributed to increased concentrations of gaseous aldehydes inside containment. SQN is actively addressing this issue and has scheduled work activities in place to address specific items during the next spring refueling outage that are suspected of being the source of the problem.
By CINs 2, 9 and 11a, TVA proposed to delete the requirement to limit the containment ventilation valves open to less than or equal to 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> per calendar year. This change is consistent with NUREG-1431, such that the standard TS does not impose a restriction on the amount of time a containment purge valve may remain open.
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Conversely, the licensee must be capable of complying with 10 CFR 100, Reactor Site Criteria.
CIN 2 has been discussed in the above sections regarding the administrative changes.
The Less Restrictive change to the LCO 3.6.1.9 operability statement includes deleting the requirement:
Operation with purge supply and exhaust isolation valves open for either purging or venting shall be limited to less than or equal to 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> per 365 days. The 365 day cumulative time period will begin every January 1.
For Unit 2, the temporary 400 hours0.00463 days <br />0.111 hours <br />6.613757e-4 weeks <br />1.522e-4 months <br /> for calendar year 2007 is also deleted.
CIN 9 deletes Action a of LCO 3.6.1.9 that requires all purge isolation valves to be closed in one hour if open in excess of the cumulative limit, or with more than one pair of containment purge system lines open, otherwise enter into shutdown requirements.
With no cumulative time restriction, CIN 11a deletes the tracking surveillance, SR 4.6.1.9.2, that determines the number of hours the containment purge and supply isolation valves have been open on a once per 7-day frequency.
SQNs 1000-hour purge time limit is based on the qualification of SQNs purge valves.
That is, the valves have met certain operability criteria and associated dose criteria as required by Branch Technical Position (BTP) Containment System Branch (CSB) 6-4, Revision 2, Containment Purging during Normal Plant Operations. Following issuance of SQNs full power license in the early 1980s, SQNs containment ventilation system and purge valves were upgraded and further qualified to conform to NUREG-0737,Section II.E.4.2 for Containment Isolation Dependability. Plant modifications were performed to install stops on the purge valves (8, 12, and 24 inch), that limited valve opening to 50 degrees open. This modification, and the addition of debris screens in conjunction with testing and analysis, provided assurance that the valves would close when required under DBE conditions, and fully addressed the NRC concern related to purge valve reliability.
A full discussion of SQNs Reactor Building Purge Ventilation System and its design features are provided in Section 9.4.7 and 6.2.4 of the SQN UFSAR.
SQN has reviewed this proposed change against 10 CFR 50.36 criteria and the select Standard Review Plan (SRP) 6.2.4, Revision 2, criteria. The results of this review are present hereafter.
Criterion 1 requires TS LCO be established if installed instrumentation that is used to detect, and indicate in the control room, a significant abnormal degradation of the reactor coolant pressure boundary.
LCO 3.6.1.9: The SQN containment ventilation system supply and exhaust valves and the cumulative time restriction of 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> are not installed instrumentation that is used to detect, and indicate in the control room, a significant abnormal degradation of the reactor coolant pressure boundary. Instrumentation is installed and indicates in the control room to the extent that purge valves are open or closed.
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Criterion 2. A process variable, design feature, or operating restriction that is an initial condition of a design basis accident or transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.
LCO 3.6.1.9: The SQN containment ventilation system supply and exhaust valves included within the RBPV system maintains the environment in the primary and secondary containment within acceptable limits for equipment operation and for personnel access during inspection, testing, maintenance, and refueling operations, and to limit the release of radioactivity to the environment and do not provide or are considered a process variable, design feature, or operating restriction that is an initial condition of a DBE or transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.
The cumulative time restriction of 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> for the valves being open during normal plant operation is the result of concerns regarding containment ventilation system supply and exhaust valves operability and to facilitate compliance with 10 CFR Part 100. As such, the time limit is not a process variable, design feature, or operating restriction that is an initial condition of a DBE or transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.
Criterion 3. A structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a design basis accident or transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.
LCO 3.6.1.9: The SQN containment ventilation system supply and exhaust valves are required and designed to isolate upon receiving a Phase A, Phase B, and containment ventilation isolation signal within 4 seconds. This requirement ensures the assumptions of the safety analysis are met, including the effect purging has on containment backpressure for ECCS performance analysis and minimizing the loss of reactor coolant inventory during major accidents. Because the containment ventilation system supply and exhaust valves mitigate the consequences of a DBE, LCO 3.6.3 retains conditions to provide assurance that the containment purge valves will perform their designed safety functions to minimize the loss of reactor coolant inventory and establish the containment boundary during accidents.
The cumulative time restriction of 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> for these valves being open during normal plant operation is the result of concerns regarding containment ventilation system supply and exhaust valves operability and to facilitate compliance with 10 CFR 100 requirements.
Operability is assured by performance of SRs and valve modifications to restrict opening of the valves to 50 degrees of normal full open to meet NUREG-0737, II.E.4.2 Containment Isolation Dependability. The time limit is not a structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a DBE or transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.
Criterion 4. A structure, system, or component which operating experience or probabilistic risk assessment has shown to be significant to public health and safety.
LCO 3.6.1.9: The SQN containment ventilation system supply and exhaust purge valves are involved in risk dominant sequences that lead to releases to the environment. The E1-35
containment purge valves are also modeled in the Probability Safety Assessment (PSA) assuming they are open 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> per year. Should a core damage event occur with these valves initially open and they fail-to-close, a large early release occurs. This failure could result in offsite dose consequence during DBE. To this end, the containment purge valves have been identified to satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii) and no proposal has been made to remove them from the TSs.
The 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> that the containment purge valves are open is modeled in the PSA as the fraction of the year that a failure-to-close of both valves results in an unisolated containment. Based on SQNs recent operating experience, the valves would be expected to be open for slightly greater than the 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> assumed in the PSA, but are also more reliable than modeled in the PSA. SQNs periodic test history and operating experience shows good performance relative to meeting actuation closure time within 4 seconds and local leak rate acceptance criterion. One issue regarding valve actuation has occurred, but since resolved with a valve modification. Because the purge isolation valves are highly reliable, there is no need to restrict the time that they may be open. That is, increasing the amount of time that the valves are open results in a negligible increase in the probability of an unisolated containment following a core damage event. As such, the 1000 hour0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> time restriction on open purge valves in the TSs is not a structure, system, or component which operating experience or probabilistic risk assessment has shown to be significant to public health and safety.
In accordance with the 10 CFR 50.36, the proposed change to eliminate the time limit restriction placed on the operation of the containment purge valves is acceptable based on the above criteria evaluation.
SQNs review of the SRP 6.2.4 centers on Acceptance Criteria II.6.n. In particular, the SRP provided additional guidance under Branch Technical Position (BTP) 6-4 for those plants with construction permit application issued prior to July 1, 1975, such as SQN. The SRP stated BTP Items B.1.c and B.5.a, regarding the size of the purge system used during normal plant operation and the justification by acceptable dose-consequences analysis may be waived if the applicant commits to limit the use of the purge system to less than 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br /> per year while the plant is in the startup, power, hot standby, and hot shutdown modes of operations.
BTP B.1.c The size of the lines should not exceed about eight inches in diameter, unless detailed justification for larger line sizes is provided, to improve the reliability and performance capability of the isolation and containment functions as required by General Design Criterion 54, and to facilitate compliance with the requirements of Appendix K to 10 CFR Part 50 regarding the containment pressure used in evaluating the emergency core cooling system effectiveness and 10 CFR Part 100 regarding the offsite radiological consequences.
SQNs purge system valves range in sizes from 8 to 24 inches. A review of SQNs periodic test history and operating experience shows good performance relative to meeting actuation closure time within 4 seconds and local leak rate acceptance criterion.
One issue regarding valve actuation has occurred, but since resolved with a design change. The SQN design criterion for these valves state the maximum closure time is 4 seconds. Also, the design criterion for leakage of the 24-inch isolation valves is 0.006 La, which is at least 700 percent less allowable leakage than allowed by TSs.
SQN UFSAR Section 15.4.1.1.5, Effect of Containment Purge evaluates the impact of E1-36
purging containment during a LOCA. The results of the evaluation indicate the impact of the reduced containment pressure on ECCS performance has been included in the calculated peak cladding temperature. As such, basing the plant TS peaking factor on this result permits purging of the SQN containment during normal operation to be conducted through three sets of purge lines. However, SQN is limited to using only one purge line during normal operations and is not proposing a change to the number of open lines.
During licensing of the SQN, NRC performed a dose consequence analysis for an assumed LOCA while the containment was being purged, found in Reference 7. In performing the analysis, NRC assumed the largest pair of lines (a 24-inch inlet line and a 24-inch outlet line) to be open. A pre-existing iodine spike in the reactor coolant system fluid and 4-second valve closure times were also assumed. NRCs analysis showed that in the event of a LOCA during purge operation, site boundary doses would not exceed the dose guidelines of 10 CFR Part 100. SQNs offsite dose calculations also agree that the consequences of a LOCA will not result in exceeding the dose limit of 10 CFR Part 100.
BTP 5. The following analyses should be performed to justify the containment purge system design:
- a. An analysis of the radiological consequences of a loss-of-coolant accident. The analysis should be done for a spectrum of break sizes, and the instrumentation and setpoints that will actuate the purge valves closed should be identified. The source term used in the radiological calculations should be based on a calculation under the terms of Appendix K to determine the extent of fuel failure and the concomitant release of fission products, and the fission product activity in the primary coolant. A pre-existing iodine spike should be considered in determining primary coolant activity. The volume of containment in which fission products are mixed should be justified, and the fission products from the above sources should be assumed to be released through the open purge valves during the maximum interval required for valve closure. The radiological consequences should be within 10 CFR Part 100 guideline values.
SQN has performed a calculation that determines the offsite dose due to a LOCA, Reference 8.
As mentioned above, the containment ventilation system supply and exhaust valves are required and designed to isolate upon receiving a Phase A, Phase B, and containment ventilation isolation signal within 4 seconds. Instrumentation time response accounts for 1.5 seconds of delay for a total of 5.5 seconds for purge valve closure. Source terms are in accordance with Regulatory Guide 1.4, Assumptions Used for Evaluating the Potential Radiological Consequences of a Loss of Coolant Accident for Pressurized Water Reactors, and are based on an average 1000 effective full power days (EFPD) reactor core with an enrichment of 5 percent U-235. Because the purge valves are assumed to close within 5.5 seconds from the start of the event, only reactor coolant activity source terms are released. The reactor coolant source terms are in accordance with ANSI-ANS 18.1-1984, Radioactive Source Term for Normal Operation of Light Water Reactors. The iodine activity in the reactor coolant is increased by 10 fold providing a pre-existing iodine spike. Break spectrums are not considered in this analysis; although, are considered for the ECCS analysis. This analysis considers a large break LOCA which is bounding of other DBE for 10 CFR Part 100 limits.
The volume of containment released through one set of purge lines is determined by E1-37
volume rate release calculation through the RBPV lines. This calculation used several conservative assumptions which maximize the volume displaced from containment.
These assumptions include a constant differential pressure that is 25 percent greater than containment design pressure of 12 psig; no frictional flow losses are accounted for in the system lines; a high density air-steam mixture; and the valves are fully open during the entire period and then instantaneously close. This volume of containment atmosphere release is considered fully mixed with the reactor coolant fission products. The current calculation, Reference 8, assumes the one set of purge lines are open for only 5 seconds for containment release rather than 5.5 seconds. This discrepancy of one half second has been documented in the Corrective Action Program for resolution. None-the-less, giving consideration to the conservatisms of the volume rate calculation and the fact that reactor coolant source terms are only present during this phase of the event, the additional consequence is insignificant compared to the core releases. The analysis results are provided in the below table.
No EGTS 2-hours @ EAB (rem) 30-day @ LPZ (rem) 10 CFR 100 Limit (rem)
Failure Gamma 8.11 1.54 25 Beta 4.8 1.4 300 Thyroid 84.9 1.71 300 Another item has been entered into the Corrective Action Program regarding the single failure capability of the emergency gas treatment system (EGTS) controller. It has been identified that a specific failure of EGTS controller could result in a greater release to the environment if not mitigated by operator action. The time for an operator to mitigate a potential EGTS failure has not been determined at this time. However, the calculated offsite dose for several time steps up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> from the start of the LOCA show that 10 CFR 100 limit are not exceeded.
48 hrs after 2-hours @ EAB (rem) 30-day @ LPZ (rem) 10 CFR 100 Limit (rem)
EGTS Failure Gamma 16.96 2.82 25 Beta 10.11 2.19 300 Thyroid 19.82 3.83 300 Based on the above discussion, TVAs proposed elimination of the purge and ventilation system operational 1000-hour limit and associated SR, identified by CINs 2 and 9, is appropriate such that the requirements of BTP 6-4, Revision 2 are fulfilled without waiver.
Less Restrictive Change to LCO 3.6.3 TVA is proposing to implement a new action consistent with NUREG-1431 LCO 3.6.3 Action C which provides requirements in the event of an inoperable containment isolation valve associated with a closed system. This change is identified by CIN 5 and is considered less restrictive than the current TS actions, because it would allow more time to isolate the affected penetration.
SQN has a limited number penetration flow paths in system, structure, or components (SSCs) designed in accordance with General Design Requirement 57, Closed System Isolation Valves. These systems, the associated penetration, isolation valve number, and applied leakage test are listed in the following table. The table also provides the TS LCO that is associated with SSC and the SR(s) that are applied for containment operability.
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Isolation Isolation App J.
Penetration SSC Inside Outside Leakage LCO/SR Containment Containment Test 4.6.3.2 1-14 No S/G 4.6.3.3 X-014A Closed Blowdown 4.6.3.2 43-58 No 4.6.3.3 4.6.3.2 1-32 No S/G 4.6.3.3 X-014B Closed Blowdown 4.6.3.2 43-64 No 4.6.3.3 4.6.3.2 1-25 No S/G 4.6.3.3 X-014C Closed Blowdown 4.6.3.2 43-61 No 4.6.3.3 4.6.3.2 1-07 No S/G 4.6.3.3 X-014D Closed Blowdown 4.6.3.2 43-55 No 4.6.3.3 CCS From 3.7.3 X-035 Excess Closed 70-85 Yes 4.6.3.2 Ltdn HX 4.6.3.3 CCS to 3.7.3 X-053 Excess Closed 70-143 Yes 4.6.3.2 Ltdn HX 4.6.3.3 AFW Test X-102 Closed 3-351C(LC) No 4.6.3.5 Line AFW Test X-104 Closed 3-352C(LC) No 4.6.3.5 Line The table identifies three SSCs that meet the criteria of GDC 57, for which application of the proposed Action f is acceptable. These SSC include component cooling water system (CCS) and AFW test lines and steam generator blowdown lines. CCS is required to be operable by LCO 3.7.3, Component Cooling Water System, for portions of CCS that serve safety-related component for normal and accident conditions. The excess letdown heat exchanger does not provide a safety function during a DBE. Therefore, applying LCO 3.6.3 for its containment isolation function is reasonable for these CCS penetrations.
To account for the SSCs that meet GDC 57 and should be applied under LCO 3.6.3, it is proposed this information be located in an appropriate Bases section. SRs in affect, as shown in the table, will continue to apply without change.
TVA is proposing to reduce the amount of technical detail within SR 4.6.3.2 and replace the text to conform to NUREG-1431 SR 3.6.3.8. The change is identified by CIN 17 and is considered partially less restrictive because it removes specific details that will no longer be controlled by 10 CFR 50.90. Administrative changes for consistency to NUREG-1431 are discussed in the section for Administrative Changes. It is proposed that details of each test signal and associated isolation valve be removed from the SR. This type of detail only provides information that would not normally have to be specifically clarified.
By this proposal, the individual test signals (i.e., Phase A, Phase B, and containment ventilation isolation, high containment pressure, and safety injection) would be moved to E1-39
the associated Bases. Moving the detail to the Bases is appropriated and provides adequate protection for health and safety of the public. The Bases are subject to the controls described in Section 6, Administrative Controls. Changes to the Bases are evaluated under the 10 CFR 50.59 criteria. Any change, using this criterion, will ensure proper review.
3.3 MORE RESTRICTIVE CHANGES More Restrictive Changes to LCO 3.6.3 For consistency with NUREG-1431, CIN 19 is proposed which provides an additional level of assurance that containment ventilation purges valves will remain operable under DBEs flow conditions and close within the specific time limit in the design criteria. This change creates a new SR similar to NUREG-1431 SR 3.6.3.10. The SR is written as:
SR 4.6.3.7 Verify each containment purge valve is blocked to restrict the valve from opening greater than or equal to 50 degrees, at least once per 18 months.
Addition of the SR satisfies SRP 6.2.4 in regards to GDC 54 for reliable performance capabilities. As previously mentioned in the discussion for CINs 2 and 9, SQN has modified the containment purge valves to limit open travel to 50 degrees. These travel-limit stops are not typically removed during refueling outage; however, the stops are verified to be installed prior to entering Mode 4.
For consistency with NUREG-1431, CIN 7 will add a requirement to Action e to perform SR 4.6.3.6 on the valve used to isolate the penetration path. SR 4.6.3.6 requires leakage rate testing of a containment purge valve. This change is conservative and assures that degradation of the resilient seal is detected and confirms that the leakage rate of the containment purge valve does not increase during the time the penetration is isolated.
Testing once per 92 days is not however a change to the test frequency, because these valves are normally tested once per quarter.
3.4 CHANGES NOT CONSISTENT TO NUREG-1431 LCO 3.6.3 Actions a and b include an exception to isolating containment vacuum relief isolation valves that is specific to SQNs design and licensing basis. The failure mode of the three isolation valves is fail-open on a loss of control air. This failure mode ensures that the containment is protected from unacceptable vacuum conditions. This design feature was chosen because the valve-open position has been evaluated as providing the greatest safety for the plant. Separately, LCO 3.6.3 Action c provides a requirement for inoperable containment vacuum relief isolation valves.
Proposed SR 4.6.3.6, CIN 16, requires leakage rate testing of a containment purge valve once per 3 months. CIN 16 does not propose extending the frequency of purge valve leakage testing to once per 184 days or within 92 days after opening a valve, similar to NUREG-1431 SR 3.6.3.7. SQNs current approved inservice inspection program requires these valves to be exercised nominally every 3 months, such that relaxation of the normal periodic testing to 184 days would be ineffective until the inservice inspection program is modified.
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NUREG-1431 SR 3.6.3.1, identified as CIN 10, verifies that containment purge valves of 42 inches in size are sealed closed every 31 days with an exception to one valve while in Condition E of NUREG-1431 LCO 3.6.3. SQNs RBPV system does not have 42-inch valves. The largest valves in the RBPV are 24 inches in diameter. Therefore, this SR is not applicable.
By CIN 11, SQN proposes SR 4.6.3.1 which verifies each purge supply and/or exhaust isolation valve is closed with an exception. The size of a purge valve is not proposed as is found in NUREG-1431 SR 3.6.3.2. SQNs purge valves range in size from 8 to 24 inches and are treated equally with respect to providing containment isolation; therefore, each purge valve should be verified closed.
CINs 12, 13, and 14 propose no actual change to SQN SRs 4.6.3.3, 4.6.3.4, and 4.6.3.5.
It is noted these SRs are consistent with NUREG-1431 with some exceptions to the SR numbering. Numbering of the SR and action statements is considered administrative.
NUREG-1431 SRs 3.6.3.6 and 3.6.3.9 identified by CINs 15 and 18, respectively, are strictly applicable to subatmospheric containment designs where as SQN is an ice condenser containment. Hence, these SRs do not apply.
CIN 19 adds a new SR to verify that each containment purge valve is restricted from fully opening. NUREG-1431 SR 3.6.3.10 uses a percent of valve travel rather than degrees of travel. SQNs proposed SR 4.6.3.10 uses 50 degrees of travel as was specified in NUREG-0737,Section II.E.4.2, Attachment 1. Secondly, SQN proposes to verify each containment purge valve is restricted regardless of its diameter.
3.5 TECHNICAL CHANGES CONCLUSION The above changes will result in changes to the UFSAR; however, the changes will not affect the UFSAR accident analysis found in Chapter 15. The above discussion provides evidence that the proposed changes are appropriate, provides more consistency to the NUREG-1431, and continues to protect the health and safety of the public.
4.0 REGULATORY EVALUATION
4.1 Applicable Regulatory Requirements/Criteria Section 182a of the Atomic Energy Act requires applicants for nuclear power plant operating licenses to include TSs as part of the license. The Commission's regulatory requirements related to the content of the TS are contained in Title 10, Code of Federal Regulations (10 CFR), Section 50.36. The TS requirements in 10 CFR 50.36 include the following categories: (1) safety limits, limiting safety systems settings and control settings, (2) LCO, (3) SRs, (4) design features, and (5) administrative controls. The isolation requirements for the containment purge supply and exhaust valves and secondary containment bypass leakage are included in the TS in accordance with 10 CFR 50.36(c)(2), "Limiting Conditions for Operation."
As stated in 10 CFR 50.59(c)(1)(i), a licensee is required to submit a license amendment pursuant to 10 CFR 50.90 if a change to the TS is required.
Furthermore, the requirements of 10 CFR 50.59 necessitate that NRC approve the TS changes before the TS changes are implemented. TVAs submittal meets the requirements of 10 CFR 50.59(c)(1)(i) and 10 CFR 50.90.
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NUREG-1431, Revision 3, Standard Technical Specifications Westinghouse Plants, provides generic recommendations for requirements associated with the operation of Westinghouse Electric Company design nuclear power plants. NUREG-1431 does not contain a specification for the containment ventilation system nor the secondary containment bypass leakage paths, but does include the operability of these in the requirements for the containment isolation valves. The proposed changes to the SQN TSs are consistent with the action and surveillance provisions for these items in the NUREG and provide the same assurance for availability of the associated isolation function. The proposed change is consistent with and meets the intent of NUREG-1431 for operability and actions for inoperable containment isolation valves.
Title 10, Energy, of the CFR, Part 100, Reactor Site Criteria, establishes approval requirements for proposed sites for stationary power and testing reactors. Within this part, the limits for total radiation dose to the whole body and the total radiation dose to the thyroid from iodine exposure is contained. The proposed change to the SQN TSs will eliminate the cumulative time limit of 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> for operation of containment purge supply or exhaust valves. This change does not result in a significant change to the calculated total radiation dose from a design basis accident.
Appendix A of 10 CFR 50, General Design Criteria for Nuclear Power Plants, Criteria V, Reactor Containment, contains several items that can apply to the proposed change.
General Design Criteria (GDC) 52, Capability for Containment Leakage Rate Testing, and GDC 53, Provisions for Containment Testing and Inspection, discuss the need for the containment design to allow testing at design pressures and for periodic testing. The proposed change will not alter the containment design, nor will it change the frequency in which tests are performed on containment purge valves and BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING. Therefore, the testability of the containment is not affected and the criteria of GDCs 52 and 53 continue to be satisfied.
GDC 54, Piping Systems Penetrating Containment, requires piping systems penetrating primary reactor containment to 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 proposed changes do not result in physical changes to the piping systems that penetrate containment. The changes do not modify the redundancy, reliability or the performance capabilities of the containment isolation valves. Elimination of the 1000 hour0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> time limit for operation of the containment purge valves does not affect the reliability of these valves. Leakage rate limits associated with this change remain unchanged and with the same periodic test frequencies. As such, isolation of piping system that penetrate containment will continue to provide leak detection, isolation, redundant and reliable containment capabilities with the capability to be periodically test fulfilling GDC 54.
GDC 55, Reactor Coolant Pressure Boundary Penetrating Containment, and GDC 56, Primary Containment Isolation, discusses the attributes necessary to ensure that containment penetrations are capable of being properly isolated to minimize the E1-42
release of radioactive material. The proposed change revises the location of several TS requirements, although, does not make a change to the design of the SQN containment penetrations. Functional requirement of valves during accident conditions is not changed by this amendment request, nor are the automatic functions affected. Therefore, the isolation function is not degraded and the criteria of GDCs 55 and 56 continue to be satisfied.
GDC 57, Closed System Isolation Valves, requires 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 will identify these systems, structure or components (SSCs) that meet this GDC. The change will require these SSCs penetrations to be isolated if found inoperable during appropriate modes of applicable. The time for isolation is relaxed by this proposed change; however, the specified time period is reasonable considering the relative stability of the closed system (hence, reliability) to act as a penetration isolation boundary. This amendment does not change the design of the SQN containment penetrations or the functional requirement of the valves during normal or accident conditions. Therefore, the isolation function is not changed and the criteria of GDC 57 continue to be satisfied.
4.2 Precedent TVAs proposed change is in part consistent with NUREG-1431, Revision 3, Standard Technical Specifications Westinghouse Plants.
4.3 Significant Hazards Consideration The proposed SQN technical specification (TS) change will modify and realign several containment isolation subject matter TSs to the NUREG-1431, Revision 3, Standard Technical Specifications Westinghouse Plants. A primary intent of this change is to eliminate the cumulative time limit of 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> per year for purge and vent valves operation for TS Limiting Condition of Operation (LCO) 3.6.1.9, Containment Ventilation System. This change, consistent with NUREG-1431, will be accomplished by eliminating the 1000 hour0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> per unit per year limit on containment ventilation system operation, specified in TS 3.6.1.9, including elimination of the associated action and surveillance requirement (SR). Additional changes are requested to approach conformance with NUREG-1431. These changes include revising and relocating appropriate actions and SRs of TS 3.6.1.2, Secondary Containment Bypass Leakage and TS 3.6.1.9 to TS 3.6.3, Containment Isolation Valves and TS 6.8.4.h, Containment Leakage Rate Testing Program, as necessary. The definition of Containment Integrity and TS 3.9.4, Containment Building Penetrations, are revised for fidelity.
TVA has evaluated whether or not a significant hazards consideration is involved with the proposed amendments by focusing on the three standards set forth in 10 CFR 50.92, Issuance of Amendment, as discussed below:
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- 1. Does the proposed amendment involve a significant increase in the probability or consequences of an accident previously evaluated?
Response: No.
TVAs proposed changes that involve administrative change, including relocation of actions or SRs to another LCO or to the TS administrative controls section; revision of text to conform with NUREG-1431 and add clarity; minor revision to definitions and other LCOs for fidelity; and deletion of Type A leakage test performance deferral information, do not result in technical changes to requirements currently present in the TS. These changes are administrative in nature and do not impact initiators of analyzed events. They also do not impact the assumed mitigation of accidents or transients events.
Therefore, these changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.
TVAs proposed change eliminates an hourly time limit for operation of the containment purge supply and exhaust isolation valves. This change also eliminates associated actions and SRs. The containment purge and ventilation system is qualified and designed to isolate in the event of a design basis accident (DBA). The probability of occurrence of an accident is not increased by deletion of the time limit nor will it affect the systems capability for purge valve closure or containment isolation. This change does not result in a modification of the reactor building purge ventilation (RBPV) system.
Consequently, the 10 CFR 100 limits for site boundary dose will not be exceeded in the event of an accident during containment purge operation.
Therefore, the proposed amendment does not involve a significant increase in the probability or consequences of an accident previously evaluated.
TVA proposes to implement a new required action for systems that meet the criteria of general design requirement (GDC) 57 for closed system. The change would provide relaxation of the completion time for isolation of a penetration flow path for the identified systems. This change does not result in any plant modification; therefore, the systems will continue to mitigate the consequences of a DBA. The proposed completion time is reasonable and is consistent with standard industry guidelines to ensure the accident mitigation equipment will be restored in a timely manner. The allow completion time for isolation is not a precursor to any DBE; thus, no increase in the probability of accident previously evaluated is considered. Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
TVAs proposed change reduces the amount of technical details of an SR and relocates it to a licensee-controlled document under the control of 10 CFR 50.59. The reduction in information is consistent with NUREG-1431. This change does not result in any hardware or operating procedure changes.
Requirements to perform surveillances of the systems detailed in the information are not eliminated. The details being removed from the TSs are not assumed to be an initiator of any analyzed event and therefore would not involve a significant increase in the probability of an accident. This information also does not impact the assumed mitigation of accidents or transients events.
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Therefore, these changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.
TVAs proposed change adds a more restrictive requirement to conform to NUREG-1431 in support of eliminating the hourly time limit for the operation of the containment purge isolation valves. This change will require a verification that open travel restrictors are in the containment purge valves during modes of applicability. The change will also require conditional leakage testing of a containment purge valve used to isolate a penetration. This change does not result in a modification of the RBPV system as the restrictors were installed during initial plant licensing. Leakage testing is not a new requirement for these valves. These changes provide a more stringent requirement that previously existed in the TSs. These more stringent requirements do not result in operation that will increase the probability of initiating an analyzed event. This change assists in the operability of the containment purge supply and exhaust isolation valves. Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.
- 2. Does the proposed amendment create the possibility of a new or different kind of accident from any accident previously evaluated?
Response: No.
TVAs proposed changes that involve administrative change, including relocation of actions or SRs to another LCO or to the TS administrative controls section; revision of text to conform with NUREG-1431 and add clarity; minor revision to definitions and other LCOs for fidelity; and deletion of Type A leakage test performance deferral information, do not result in technical changes to requirements currently present in the TS. These changes do not involve a physical alteration of the plant (no new or different type of equipment will be installed) or changes in the methods governing normal plant operations. These changes will not impose any new or different requirements or eliminate any existing requirements. Therefore, this change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
TVAs proposed change eliminates an hourly time limit for operation of the containment purge supply and exhaust isolation valves. This change also eliminates associated actions and SRs. This change does not involve a change to plant systems, components, or operating practices that could result in a change in accident generation potential. The containment purge supply and exhaust valves are utilized for the isolation of flow paths to the environs and are not a feature that could generate a postulated accident. Elimination of the operational time restriction of the containment purge supply and exhaust isolation valves will not impact the potential for accidents. Therefore, this proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.
TVA proposes to implement a new required action for systems that meet the closed system design. The change would provide relaxation of the completion time for isolation of a penetration flow path for the identified systems. This E1-45
change does not involve a physical alteration of the plant (no new or different type of equipment will be installed) or require any unusual operator actions.
The proposed change will not alter the way any structure, system, or component functions, and will not alter the manner the plant is operated. The response of the plant and the operators following an accident will not be different. The change does not introduce any new failure modes. Therefore, this proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.
TVAs proposed change reduces the amount of technical details of an SR and relocates it to a licensee-controlled document under the control of 10 CFR 50.59. The reduction in information is consistent with NUREG-1431 and adequate control of the information will be maintained. This change does not involve a physical alteration of the plant (no new or different type of equipment will be installed) or changes in testing requirements of these systems. This change will not alter assumptions made in the safety analysis and licensing basis. Therefore, this proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.
TVAs proposed change adds a more restrictive requirement to conform to NUREG-1431 in support of eliminating the hourly time limit for the operation of the containment purge isolation valves. This change will require a verification that open travel restrictors are in the containment purge valves during modes of applicability. The change will also require conditional leakage testing of a containment purge valve used to isolate a penetration. This change does not result in a modification of the RBPV system as the restrictors were installed during initial plant licensing. Leakage testing is not a new requirement for these valves. Verification of restrictors does not modify normal plant operations, but does impose different administrative requirements. Action required leakage rate testing of an isolated containment purge valve does create new requirements. However, these changes will maintain the assumptions in the safety analyses and licensing basis. Therefore, this proposed change does not create the possibility of a new or different kind of accident from any previously evaluated.
- 3. Does the proposed amendment involve a significant reduction in a margin of safety?
Response: No.
TVAs proposed changes that involve administrative change, including relocation of actions or SRs to another LCO or to the TS administrative controls section; revision of text to conform with NUREG-1431 and add clarity; minor revision to definitions and other LCO for fidelity; and deletion of Type A leakage test performance deferral information, do not result in technical changes to requirements currently present in the TS. These changes will not reduce a margin of safety because it has no impact on any safety analysis assumptions. Also, since these changes are administrative in nature, no question of safety is involved. Therefore, these changes do not involve a significant reduction in a margin of safety.
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TVAs proposed change eliminates an hourly time limit for operation of the containment purge supply and exhaust isolation valves. This change also eliminates associated actions and SRs. The proposed change does not alter plant systems or their setpoints that are used to maintain the margin of safety.
Operability will continue to be maintained by testing and verification requirements on the containment purge valves. Therefore, the proposed change does not involve a reduction in a margin of safety.
TVA proposes to implement a new required action for systems that meet the closed system design. The change would provide relaxation of the completion time for isolation of a penetration flow path for the identified systems. This change does not result in any plant modification, testing requirements to ensure operability, or a change in safety limits or safety system settings. The proposed completion time is reasonable and is consistent with standard industry guidelines to ensure the accident mitigation equipment will be restored in a timely manner. Therefore, the proposed change does not involve a reduction in a margin of safety.
TVAs proposed change reduces the amount of technical details of an SR and relocates it to a licensee-controlled document under the control of 10 CFR 50.59. This change does not reduce the margin of safety since the location of the details has no impact on any safety assumptions. Therefore, the proposed change does not involve a reduction in a margin of safety.
TVAs proposed change adds a more restrictive requirement to conform to NUREG-1431 in support of eliminating the hourly time limit for the operation of the containment purge isolation valves. This change will require a verification that open travel restrictors are in the containment purge valves during modes of applicability. The change will also require conditional leakage testing of a containment purge valve used to isolate a penetration. Adding more stringent requirements, by definition, provides additional restrictions to enhance plant safety. As such, no question of safety is involved. Therefore, the proposed changes do not involve a significant reduction in a margin of safety.
Based on the above, TVA concludes that the proposed amendment does not involve a 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 Conclusions 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 Commissions 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.
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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.
However, the proposed amendment does not involve (i) a significant hazards consideration, (ii) a significant change in the types or 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. TVA letter from L. M. Mills to NRC, Mr. A. Schwencer, dated January 8, 1981, regarding revision to Unit 1 TS LCO 3.6.1.9.
- 2. TVA letter from L. M. Mills to NRC, Mr. Harold R. Denton, dated February 10, 1981, regarding a license amendment request of Unit 1 TS LCO 3.6.1.9. with supplemental information.
- 3. NRC letter to TVA dated April 15, 1981, Issuance of Amendment No. 5 to Facility Operating License No. DRP Sequoyah Nuclear Plant Unit 1.
- 4. TVA letter from L. M. Mills to NRC, Ms. E. Adensam dated December 28, 1982, operating experience of purge/vent system operation as requested in Safety Evaluation Report for Amendment No. 5.
- Exigent Technical Specification (TS) Change 07-06, Containment Purge and Vent System Operation.
- 6. NRC letter to TVA dated October 11, 2007, Sequoyah Nuclear Plant, Unit 2 - Issuance of Amendment Regarding Containment Purge Hour Limit (MD6757).
- 7. NRCs Safety Evaluation Report NUREG-0011, Safety Evaluation Report by the Office of Nuclear Reactor Regulation, U.S. Nuclear Regulatory Commission in the Matter of Tennessee Valley Authority Sequoyah Nuclear Plant Units 1 and 2.
- 8. TVA calculation SQNAPS3-067, Offsite and Control Room Operator Doses due to a MHA [Maximum Hypothetical] LOCA with Maximum Allowable Annulus Inleakage.
ATTACHMENTS
- 1. Technical Specifications Page Markups
- 2. Bases Page Markups E1-48
ATTACHMENT 1 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)
UNITS 1 AND 2 PROPOSED TECHNICAL SPECIFICATION CHANGES (MARK-UP)
I. AFFECTED PAGE LIST Unit 1 Index VII 1-2 3/4 6-2 3/4/6-3 3/4 6-15 3/4 6-17 3/4 6-18 3/4 9-4 6-10a Unit 2 Index VII 1-2 3/4 6-2 3/4/6-3 3/4 6-15 3/4 6-17 3/4 6-18 3/4 9-5 6-9 6-10 II. MARKED PAGES See attached.
A1-1
INSERT A
- d. With one or more BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING not within limit, restore within limit within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
- e. With one or more penetration flow paths with one or more containment purge supply and/or exhaust isolation valves not within leakage limits, isolate the affected penetration flow path by use of at least one closed and de-activated automatic valve, closed manual valve, or blind flange within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
Verify# the affected penetration flow path is isolated once per 31 days for isolation devices outside containment and prior to entering MODE 4 from MODE 5 if not performed within the previous 92 days for isolation devices inside containment. Perform SR 4.6.3.6 once per 92 days for the valve used to isolate the affected penetration flow path.
- f. With one or more penetration flow paths of a closed system design with one containment isolation valve inoperable, isolate the affected penetration flow path within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> by use of at least one closed and de-activated automatic valve, closed manual valve, or blind flange, and verify# the affected penetration is isolated once per 31 days.
INSERT B 4.6.3.1 Verify each purge supply and/or exhaust isolation valve is closed, except when containment purge valves (only one set of supply and exhaust valves open) are open for pressure control, ALARA or air quality considerations for personnel entry, or for Surveillances that require the valves to be open, at least once per 31 days.
INSERT C 4.6.3.6 Perform leakage rate testing for each containment purge supply and exhaust isolation valve at least once per 3 months.
4.6.3.7 Verify each containment purge valve is blocked to restrict the valve from opening greater than or equal to 50 degrees, at least once per 18 months.
4.6.3.8 Verify the combined leakage rate for all BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING is less than or equal to 0.25 La when pressurized to greater than or equal to Pa in accordance with the Containment Leakage Rate Test program.
INSERT D BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING leakage from isolation valves that are sealed with fluid from a seal system may be excluded, subject to the provisions of Appendix J,Section III.C.3, when determining the combined leakage rate provided the seal system and valves are pressurized to at least 1.10 Pa (13.2 psig) and the seal system capacity is adequate to maintain system pressure (or fluid head for the containment spray system and RHR spray system valves at penetrations 48A, 48B, 49A and 49B) for at least 30 days.
INSERT E
- c. For each containment purge supply and exhaust isolation valve, acceptance criteria is measured leakage rate less than or equal to 0.05 La.
- d. BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING acceptance criteria are:
- 1. The combined bypass leakage rate to the auxiliary building shall be less than or equal to 0.25 La by applicable Type B and C tests.
- 2. Penetrations not individually testable shall have no detectable leakage when tested with soap bubbles while the containment is pressurized to Pa (12 psig) during each Type A test.
A1-2
INSERT F
- a. With one or more penetration flow paths with one containment isolation valve inoperable for reasons other than:
- 1. leakage rate limits of containment purge isolation valve(s),
- 2. leakage rate limit of BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING, or
- 3. inoperable containment vacuum relief isolation valves(s),
isolate the 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 and deactivated automatic valve, closed manual valve, blind flange, or check valve## with flow through the valve secured; and, verify# the affected penetration flow path is isolated once per 31 days for isolation devices outside containment, and prior to entering MODE 4 from MODE 5 if not performed within the previous 92 days for isolation devices inside containment.
- b. With one or more penetration flow paths with two containment isolation valves inoperable for reasons other than:
- 1. leakage rate limits of containment purge isolation valve(s),
- 2. leakage rate limit of BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING, or
- 3. inoperable containment vacuum relief isolation valves(s),
isolate the affected penetration within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> by use of at least one closed and deactivated automatic valve, closed manual valve, or blind flange and verify# the affected penetration flow path is isolated once per 31 days.
A1-3
INDEX LIMITING CONDITIONS FOR OPERATION AND SURVEILLANCE REQUIREMENTS SECTION PAGE 3/4.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) 3/4.5.1 ACCUMULATORS Cold Leg Injection Accumulators ........................................................................................... 3/4 5-1 Deleted ........................................................................................................................ 3/4 5-3 3/4.5.2 ECCS SUBSYSTEMS - Tavg greater than or equal to 350oF................................................. 3/4 5-4 3/4.5.3 ECCS SUBSYSTEMS - Tavg less than 350oF ........................................................................ 3/4 5-8 3/4.5.4 DELETED ...................................................................................................................... 3/4 5-10 3/4.5.5 REFUELING WATER STORAGE TANK............................................................................. 3/4 5-11 3/4 5.6 SEAL INJECTION FLOW .................................................................................................... 3/4 5-12 3/4.6 CONTAINMENT SYSTEMS 3/4.6.1 PRIMARY CONTAINMENT Containment Integrity............................................................................................................. 3/4 6-1 Secondary Containment Bypass Leakage (DELETED) ........................................................ 3/4 6-2 Containment Air Locks........................................................................................................... 3/4 6-7 Internal Pressure.................................................................................................................... 3/4 6-9 Air Temperature ................................................................................................................... 3/4 6-10 Containment Vessel Structural Integrity .............................................................................. 3/4 6-11 Shield Building Structural Integrity....................................................................................... 3/4 6-12 Emergency Gas Treatment System (Cleanup Subsystem)................................................. 3/4 6-13 Containment Ventilation System (DELETED) ..................................................................... 3/4 6-15 3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS Containment Spray Subsystems ......................................................................................... 3/4 6-16 Lower Containment Vent Coolers...................................................................................... 3/4 6-16b August 4, 2000 SEQUOYAH - UNIT 1 VII Amendment No. 67, 69, 116, 140, 150, 176, 259 A1-4
DEFINITIONS CHANNEL FUNCTIONAL TEST 1.6 A CHANNEL FUNCTIONAL TEST shall be:
- a. Analog channels - the injection of a simulated signal into the channel as close to the sensor as practicable to verify OPERABILITY including alarm and/or trip functions.
- b. Bistable channels - the injection of a simulated signal into the sensor to verify OPERABILITY including alarm and/or trip functions.
- c. Digital channels - the injection of a simulated signal into the channel as close to the sensor input to the process racks as practicable to verify OPERABILITY including alarm and/or trip functions.
CONTAINMENT INTEGRITY 1.7 CONTAINMENT INTEGRITY shall exist when:
- a. All penetrations required to be closed during accident conditions are either:
- 1) Capable of being closed by an OPERABLE containment automatic isolation valve system, or
- 2) Closed by manual valves, blind flanges, or deactivated automatic valves secured in their closed positions, except for valves that are open under administrative control as permitted by Specification 3.6.3.
- b. All equipment hatches are closed and sealed.
- c. Each air lock is in compliance with the requirements of Specification 3.6.1.3, Correct
- d. The containment leakage rates are within the limits of Specification 4.6.1.1.c, misspelling-Unit 1 only e. The sealing mechansim mechanism associated with each penetration (e.g., welds, bellows, or O-rings) is OPERABLE, and Revise for f. Secondary containment bypass leakage is within the limits of Specification 3.6.3.1.2 consistency CONTROLLED LEAKAGE 1.8 This definition has been deleted.
CORE ALTERATION 1.9 CORE ALTERATION shall be the movement of any fuel, sources, reactivity control components, or other components affecting reactivity within the reactor vessel with the head removed and fuel in the vessel. Suspension of CORE ALTERATIONS shall not preclude completion of movement of a component to a safe position.
CORE OPERATING LIMIT REPORT 1.10 The CORE OPERATING LIMITS REPORT (COLR) is the unit-specific document that provides core operating limits for the current operating reload cycle. These cycle-specific core operating limits shall be determined for each reload cycle in accordance with Specification 6.9.1.14. Unit operation within these operating limits is addressed in individual specifications.
August 4, 2000 SEQUOYAH - UNIT 1 1-2 Amendment No. 12, 71, 130, 141, 155 176, 201, 203, 259 A1-5
CONTAINMENT SYSTEMS SECONDARY CONTAINMENT BYPASS LEAKAGE (DELETED)
LIMITING CONDITION FOR OPERATION Maintained 3.6.1.2 Secondary Containment bypass leakage rates shall be limited to a combined bypass leakage rate by LCO of less than or equal to 0.25 La for all penetrations that are secondary containment BYPASS LEAKAGE 3.6.3 SR PATHS TO THE AUXILIARY BUILDING when pressurized to Pa.*
Same as APPLICABILITY: MODES 1, 2, 3 and 4.
LCO 3.6.3 ACTION:
With the combined bypass leakage rate exceeding 0.25 La for BYPASS LEAKAGE PATHS TO THE Revised and AUXILIARY BUILDING, restore the combined bypass leakage rate from BYPASS LEAKAGE PATHS TO Moved to LCO 3.6.3 THE AUXILIARY BUILDING to less than or equal to 0.25 La within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 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 /> 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 />.
Maintained Enter the ACTION of LCO 3.6.1.1, "Primary Containment" when Secondary Containment Bypass by LCO Leakage results in exceeding the overall containment leakage rate acceptance criteria.
3.6.3 October 18, 2005 SEQUOYAH - UNIT 1 3/4 6-2 Amendment No. 12, 71, 176, 203, 217 A1-6
CONTAINMENT SYSTEMS SECONDARY CONTAINMENT BYPASS LEAKAGE (DELETED)
SURVEILLANCE REQUIREMENTS Maintained 4.6.1.2 The secondary containment bypass leakage rates shall be demonstrated:
by LCO 3.6.3 SR and
- a. The combined bypass leakage rate to the auxiliary building shall be determined to be less Containment than or equal to 0.25 La by applicable Type B and C tests in accordance with the Leakage Containment Leakage Rate Test program, except for penetrations which are not individually Rate Test. testable; penetrations not individually testable shall be determined to have no detectable Program.
leakage when tested with soap bubbles while the containment is pressurized to Pa (12 psig) during each Type A test.
- b. Leakage from isolation valves that are sealed with fluid from a seal system may be Maintained excluded, subject to the provisions of Appendix J,Section III.C.3, when determining the by combined leakage rate provided the seal system and valves are pressurized to at least 1.10 Containment Pa (13.2 psig) and the seal system capacity is adequate to maintain system pressure (or Leakage Rate Test.
fluid head for the containment spray system and RHR spray system valves at penetrations Program 48A, 48B, 49A and 49B) for at least 30 days.
- c. The provisions of Specification 4.0.2 are not applicable.
February 5, 1996 SEQUOYAH - UNIT 1 3/4 6-3 Amendment No. 12, 71, 101, 102, 127, 130, 176, 217 A1-7
CONTAINMENT SYSTEMS CONTAINMENT VENTILATION SYSTEM (DELETED)
LIMITING CONDITION FOR OPERATION Maintained 3.6.1.9 One pair (one purge supply line and one purge exhaust line) of containment purge system lines by LCO may be open; the containment purge supply and exhaust isolation valves in all other containment purge 3.6.3 SR lines shall be closed. Operation with purge supply or exhaust isolation valves open for either purging or venting shall be limited to less than or equal to 1000 hours0.0116 days <br />0.278 hours <br />0.00165 weeks <br />3.805e-4 months <br /> per 365 days. The 365 day cumulative time period will begin every January 1.
Same as LCO 3.6.3 APPLICABILITY: MODES 1, 2, 3, and 4.
ACTION:
Deleted cumulative a. With a purge supply or exhaust isolation valve open in excess of the above cumulative limit, or limit and with more than one pair of containment purge system lines open, close the isolation valve(s) in the move one pair of lines purge line(s) within one hour 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 /> and in COLD limit to LCO SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
3.6.3
- b. With a containment purge supply and/or exhaust isolation valve having a measured leakage rate in Revised and excess of 0.05 La, restore the inoperable valve to OPERABLE status or isolate the affected moved to by penetration flow path by use of at least one closed and de-activated automatic valve, closed LCO 3.6.3 manual valve, or blind flange within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Verify** the affected penetration flow path is isolated once per 31 days for isolation devices outside containment and prior to entering Mode 4 from Mode 5 if not performed within the previous 92 days for isolation devices inside containment.
Otherwise 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 />.
SURVEILLANCE REQUIREMENTS Revised and 4.6.1.9.1 The position of the containment purge supply and exhaust isolation valves shall be determined moved to at least once per 31 days.
LCO 3.6.3 Deleted 4.6.1.9.2 The cumulative time that the purge supply and exhaust isolation valves are open over a 365 day period shall be determined at least once per 7 days.
Revised and 4.6.1.9.3 At least once per 3 months, each containment purge supply and exhaust isolation valve shall moved to be demonstrated OPERABLE by verifying that the measured leakage rate is less than or equal to 0.05 LCO 3.6.3 La.*
Maintained by LCO
- Enter the ACTION of LCO 3.6.1.1, "Primary Containment" when purge valve leakage results in 3.6.3 exceeding the overall containment leakage rate acceptance criteria.
- Isolation devices in high radiation areas may be verified by use of administrative means. Isolation devices that are locked, sealed, or otherwise secured may be verified by use of administrative means.
April 11, 2005 SEQUOYAH - UNIT 1 3/4 6-15 Amendment No. 18, 120, 176, 217, 290, 301 A1-8
CONTAINMENT SYSTEMS 3/4.6.3 CONTAINMENT ISOLATION VALVES LIMITING CONDITION FOR OPERATION Insert LCO 3.6.3 Each containment isolation valve shall be OPERABLE.*
Notes APPLICABILITY: MODES 1, 2, 3 and 4.
Insert Action Notes ACTION:
Adds a. With one or more penetration flow paths with one containment isolation valve inoperable; except exception for containment vacuum relief isolation valves(s), 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 /> for purge valves and by use of at least one closed deactivated automatic valve, closed manual valve, blind flange, or BYPASS check valve## with flow through the valve secured; and, verify# the affected penetration flow path LEAKAGE is isolated once per 31 days for isolation devices outside containment, and prior to entering PATHS TO MODE 4 from MODE 5 if not performed within the previous 92 days for isolation devices inside THE AUXILIARY containment.
BUILDING
- b. With one or more penetration flow paths with two containment isolation valves inoperable; except INSERT F for containment vacuum relief isolation valves(s), isolate each affected penetration within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> by use of at least one closed deactivated automatic valve, closed manual valve, or blind flange and verify# the affected penetration flow path is isolated once per 31 days.
- c. With one or more containment vacuum relief isolation valve(s) inoperable, the valve(s) must be returned to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
Insert A dg. With any of the above ACTIONS not met, 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 />.
Insert SR SURVEILLANCE REQUIREMENTS Note Insert B 4.6.3.1 Deleted Relocated to *1. Penetration flow path(s) may be unisolated intermittently under administrative controls.
below LCO statement address as 2. Enter the ACTION of LCO 3.6.1.1, "Primary Containment" when containment isolation valve NOTES leakage results in exceeding the overall containment leakage rate acceptance criteria.
- 3. Isolation devices in high radiation areas may be verified by use of administrative means.
Relocated to before the Action #4. Isolation devices that are locked, sealed, or otherwise secured may be verified by use of requirement administrative means.
s address as NOTES
- 5. A check valve with flow through the valve secured is only applicable to penetration flow paths with two containment isolation valves.
April 11, 2005 SEQUOYAH - UNIT 1 3/4 6-17 Amendment No. 12, 197, 203, 217, 254, 301 A1-9
CONTAINMENT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)
Removal of 4.6.3.2 Verify each automatic containment isolation valve that is not locked, sealed or otherwise excessive details. secured in position, actuates to the isolation position on an actual or simulated actuation signal, at least once per 18 months.Each automatic containment isolation valve shall be demonstrated OPERABLE 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 Containment Ventilation isolation test signal, each Containment Ventilation Isolation valve actuates to its isolation position.
- d. Verifying that on a high containment pressure isolation test signal, each Containment Vacuum Relief Valve actuates to its isolation position.
- e. Verifying that on a Safety Injection test signal that the Normal Charging Isolation valve actuates to its isolation position.
4.6.3.3 The isolation time of each power operated or automatic containment isolation valve shall be determined to be within its limit when tested pursuant to Specification 4.0.5.
4.6.3.4 Verify each containment isolation manual valve and blind flange that is located inside containment and not locked, sealed, or otherwise secured and required to be closed during accident conditions is closed, except for containment isolation valves that are open under administrative controls prior to entering Mode 4 from Mode 5 if not performed within the previous 92 days.*
4.6.3.5 Verify each containment isolation manual valve and blind flange that is located outside containment and not locked, sealed, or otherwise secured and required to be closed during accident conditions is closed, except for containment isolation valves that are open under administrative controls, at least once per 31 days.*
Insert C Relocated to before the
- NOTE: Valves and blind flanges in high radiation areas may be verified by use of SRs administrative means.
October 24, 2001 SEQUOYAH - UNIT 1 3/4 6-18 Amendment No. 12, 81, 101, 120, 203, 254, 271 A1-10
REFUELING OPERATIONS 3/4.9.4 CONTAINMENT BUILDING PENETRATIONS LIMITING CONDITION FOR OPERATION 3.9.4 The containment building penetrations shall be in the following status:
- a. The equipment door closed and held in place by a minimum of four bolts,
- b. A minimum of one door in each airlock is closed, and both doors of both containment personnel airlocks may be open if:
- 1. One personnel airlock door in each airlock is capable of closure, and
- 2. One train of the Auxiliary Building Gas Treatment System is OPERABLE in accordance with Technical Specification 3.9.12, and
- c. Each penetration* providing direct access from the containment atmosphere to the outside atmosphere shall be either:
- 1. Closed by an isolation valve, blind flange, manual valve, or equivalent, or
- 2. Be capable of being closed by an OPERABLE automatic Containment Ventilation isolation valve.
APPLICABILTY:
3.9.4.a. Containment Building Equipment Door - During movement of recently irradiated fuel within the containment.
3.9.4.b. and c. Containment Building Airlock Doors and Penetrations - During movement of irradiated fuel within the containment.
ACTION:
- 1. With the requirements of the above specification not satisfied for the containment building equipment door, immediately suspend all operations involving movement of recently irradiated fuel in the containment building. The provisions of Specification 3.0.3 are not applicable.
- 2. With the requirements of the above specification not satisfied for containment airlock doors or penetrations, immediately suspend all operations involving movement of irradiated fuel in the containment building. The provisions of Specification 3.0.3 are not applicable.
SURVEILLANCE REQUIREMENTS 4.9.4 Each of the above required containment building penetrations shall be determined to be either in its required condition or capable of being closed by an OPERABLE automatic Containment Ventilation isolation valve once per 7 days during movement of irradiated fuel in the containment building by:
Associated
- a. Verifying the penetrations are in their required condition, or with removal of excessive b. VerifyingTesting the Containment Ventilation isolation valves not locked, sealed, or details in SR otherwise secured in position, actuate to the isolation position on an actual or simulated 4.6.3.2. actuation signal.per the applicable portions of Specification 4.6.3.2.
- Penetration flow path(s) providing direct access from the containment atmosphere that transverse and terminate in the Auxiliary Building Secondary Containment Enclosure may be unisolated under administrative controls.
October 28, 2003 SEQUOYAH - UNIT 1 3/4 9-4 Amendment No. 12, 209, 249, 260, 288 A1-11
- h. Containment Leakage Rate Testing Program A program shall be established to implement the leakage rate testing of the containment as required by 10 CFR 50.54(o) and 10 CFR 50 Appendix J, Option B, as modified by approved exemptions. Visual examination and testing, including test intervals and extensions, shall be in accordance with Regulatory Guide (RG) 1.163, "Performance-Based Containment Leak-Test Program," dated September 1995 with exceptions provided in the Deleted Type A site implementing instructions and the following:. Performance of the spring 2003 extension containment integrated leakage rate (Type A) test may be deferred up to 5 years but no and add later than spring 2008.
Insert D The peak calculated containment internal pressure for the design basis loss of coolant accident, Pa, is 12.0 psig.
The maximum allowable containment leakage rate, La, at Pa, is 0.25% of the primary containment air weight per day.
Leakage rate acceptance criteria are:
- a. Containment overall leakage rate acceptance criteria is 1.0 La. During the first unit startup following testing in accordance with this program, the leakage rate acceptance criteria are 0.60 La for the combined Type B and Type C tests, and 0.75 La for Type A tests;
- b. Air lock testing acceptance criteria are:
- 1. Overall air lock leakage rate is 0.05 La when tested at Pa.
- 2. For each door, leakage rate is 0.01 La when pressurized to 6 psig for at least two minutes.
Insert E The provisions of SR 4.0.2 do not apply to the test frequencies specified in the Containment Leakage Rate Testing Program.
The provisions of SR 4.0.3 are applicable to the Containment Leakage Rate Testing Program.
- i. Configuration Risk Management Program (DELETED)
May 29, 2003 SEQUOYAH - UNIT 1 6-10a Amendment No. 217, 241, 281, 287 A1-12
INDEX LIMITING CONDITIONS FOR OPERATION AND SURVEILLANCE REQUIREMENTS SECTION PAGE 3/4.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) 3/4.5.1 ACCUMULATORS Cold Leg Injection Accumulators ........................................................................................... 3/4 5-1 Deleted ........................................................................................................................ 3/4 5-3 3/4.5.2 ECCS SUBSYSTEMS - Tavg greater than or equal to 350oF................................................. 3/4 5-4 3/4.5.3 ECCS SUBSYSTEMS - Tavg less than 350oF ........................................................................ 3/4 5-8 3/4.5.4 DELETED ...................................................................................................................... 3/4 5-10 3/4.5.5 REFUELING WATER STORAGE TANK............................................................................. 3/4 5-11 3/4 5.6 SEAL INJECTION FLOW .................................................................................................... 3/4 5-12 3/4.6 CONTAINMENT SYSTEMS 3/4.6.1 PRIMARY CONTAINMENT Containment Integrity............................................................................................................. 3/4 6-1 Secondary Containment Bypass Leakage (DELETED) ........................................................ 3/4 6-2 Containment Air Locks........................................................................................................... 3/4 6-7 Internal Pressure.................................................................................................................... 3/4 6-9 Air Temperature ................................................................................................................... 3/4 6-10 Containment Vessel Structural Integrity .............................................................................. 3/4 6-11 Shield Building Structural Integrity....................................................................................... 3/4 6-12 Emergency Gas Treatment System (Cleanup Subsystem)................................................. 3/4 6-13 Containment Ventilation System (DELETED) ..................................................................... 3/4 6-15 3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS Containment Spray Subsystems ......................................................................................... 3/4 6-16 Lower Containment Vent Coolers...................................................................................... 3/4 6-16b August 4, 2000 SEQUOYAH - UNIT 2 VII Amendment Nos. 59, 61, 131, 140, 167, 250 A1-13
DEFINITIONS CHANNEL FUNCTIONAL TEST 1.6 A CHANNEL FUNCTIONAL TEST shall be:
- a. Analog channels - the injection of a simulated signal into the channel as close to the sensor as practicable to verify OPERABILITY including alarm and/or trip functions.
- b. Bistable channels - the injection of a simulated signal into the sensor to verify OPERABILITY including alarm and/or trip functions.
- c. Digital channels - the injection of a simulated signal into the channel as close to the sensor input to the process racks as practicable to verify OPERABILITY including alarm and/or trip functions.
CONTAINMENT INTEGRITY 1.7 CONTAINMENT INTEGRITY shall exist when:
- a. All penetrations required to be closed during accident conditions are either:
- 1) Capable of being closed by an OPERABLE containment automatic isolation valve system, or
- 2) Closed by manual valves, blind flanges, or deactivated automatic valves secured in their closed positions, except for valves that are open under administrative control as permitted by Specification 3.6.3.
- b. All equipment hatches are closed and sealed.
- c. Each air lock is in compliance with the requirements of Specification 3.6.1.3, Grammatical d. The containment leakage rates are within the limits of Specification 4.6.1.1.c, and correction
- e. The sealing mechanism associated with each penetration (e.g., welds, bellows, or O-rings) is OPERABLE, and Revise for f. Secondary containment bypass leakage is within the limits of Specification 3.6.3.1.2 consistency CONTROLLED LEAKAGE 1.8 This definition has been deleted.
CORE ALTERATION 1.9 CORE ALTERATION shall be the movement of any fuel, sources, reactivity control components, or other components affecting reactivity within the reactor vessel with the head removed and fuel in the vessel. Suspension of CORE ALTERATIONS shall not preclude completion of movement of a component to a safe position.
CORE OPERATING LIMITS REPORT 1.10 The CORE OPERATING LIMITS REPORT (COLR) is the unit-specific document that provides core operating limits for the current operating reload cycle. These cycle-specific core operating limits shall be determined for each reload cycle in accordance with Specification 6.9.1.14. Unit operation within these operating limits is addressed in individual specifications.
August 4, 2000 SEQUOYAH - UNIT 2 1-2 Amendment Nos. 63, 117, 132, 146, 167, 191, 193, 250 A1-14
CONTAINMENT SYSTEMS SECONDARY CONTAINMENT BYPASS LEAKAGE (DELETED)
LIMITING CONDITION FOR OPERATION Maintained 3.6.1.2 Secondary Containment bypass leakage rates shall be limited to a combined bypass leakage rate by LCO of less than or equal to 0.25 La for all penetrations that are secondary containment BYPASS LEAKAGE 3.6.3 SR PATHS TO THE AUXILIARY BUILDING when pressurized to Pa.*
Same as APPLICABILITY: MODES 1, 2, 3 and 4.
LCO 3.6.3 ACTION:
With the combined bypass leakage rate exceeding 0.25 La for BYPASS LEAKAGE PATHS TO THE Revised and AUXILIARY BUILDING, restore the combined bypass leakage rate from BYPASS LEAKAGE PATHS TO Moved to LCO 3.6.3 THE AUXILIARY BUILDING to less than or equal to 0.25 La within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 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 /> 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 />.
Maintained Enter the ACTION of LCO 3.6.1.1, "Primary Containment" when Secondary Containment Bypass by LCO Leakage results in exceeding the overall containment leakage rate acceptance criteria.
3.6.3 February 5, 1996 SEQUOYAH - UNIT 2 3/4 6-2 Amendment No. 63, 167, 193, 207 A1-15
CONTAINMENT SYSTEMS SECONDARY CONTAINMENT BYPASS LEAKAGE (DELETED)
SURVEILLANCE REQUIREMENTS Maintained 4.6.1.2 The secondary containment bypass leakage rates shall be demonstrated:
by LCO 3.6.3 SR and
- a. The combined bypass leakage rate to the auxiliary building shall be determined to be less Containment than or equal to 0.25 La by applicable Type B and C tests in accordance with the Leakage Containment Leakage Rate Test program, except for penetrations which are not individually Rate Test. testable; penetrations not individually testable shall be determined to have no detectable Program.
leakage when tested with soap bubbles while the containment is pressurized to Pa (12 psig) during each Type A test.
- b. Leakage from isolation valves that are sealed with fluid from a seal system may be Maintained excluded, subject to the provisions of Appendix J,Section III.C.3, when determining the by combined leakage rate provided the seal system and valves are pressurized to at least 1.10 Containment Pa (13.2 psig) and the seal system capacity is adequate to maintain system pressure (or Leakage Rate Test.
fluid head for the containment spray system and RHR spray system valves at penetrations Program 48A, 48B, 49A and 49B) for at least 30 days.
- c. The provisions of Specification 4.0.2 are not applicable.
February 5, 1996 SEQUOYAH - UNIT 2 3/4 6-3 Amendment No. 63, 90, 104, 117, 126, 139, 167, 207 A1-16
CONTAINMENT SYSTEMS CONTAINMENT VENTILATION SYSTEM (DELETED)
LIMITING CONDITION FOR OPERATION Maintained 3.6.1.9 One pair (one purge supply line and one purge exhaust line) of containment purge system lines by LCO may be open; the containment purge supply and exhaust isolation valves in all other containment purge 3.6.3 SR lines shall be closed. Operation with purge supply or exhaust isolation valves open for either purging or venting shall be limited to less than or equal to 1000## hours per 365 days. The 365 day cumulative time period will begin every January 1.
Same as LCO 3.6.3 APPLICABILITY: MODES 1, 2, 3, and 4.
ACTION:
Deleted cumulative a. With a purge supply or exhaust isolation valve open in excess of the above cumulative limit, or limit and with more than one pair of containment purge system lines open, close the isolation valve(s) in the move one pair of lines purge line(s) within one hour 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 /> and in COLD limit to LCO SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
3.6.3
- b. With a containment purge supply and/or exhaust isolation valve having a measured leakage rate in Revised and excess of 0.05 La, restore the inoperable valve to OPERABLE status or isolate the affected moved to by penetration flow path by use of at least one closed and de-activated automatic valve, closed LCO 3.6.3 manual valve, or blind flange within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Verify** the affected penetration flow path is isolated once per 31 days for isolation devices outside containment and prior to entering Mode 4 from Mode 5 if not performed within the previous 92 days for isolation devices inside containment.
Otherwise 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 />.
SURVEILLANCE REQUIREMENTS Revised and 4.6.1.9.1 The position of the containment purge supply and exhaust isolation valves shall be determined moved to at least once per 31 days.
LCO 3.6.3 Deleted 4.6.1.9.2 The cumulative time that the purge supply and exhaust isolation valves are open over a 365 day period shall be determined at least once per 7 days.
Revised and 4.6.1.9.3 At least once per 3 months, each containment purge supply and exhaust isolation valve shall moved to be demonstrated OPERABLE by verifying that the measured leakage rate is less than or equal to 0.05 LCO 3.6.3 La.*
Maintained by LCO
- Enter the ACTION of LCO 3.6.1.1, "Primary Containment" when purge valve leakage results in 3.6.3 exceeding the overall containment leakage rate acceptance criteria.
- Isolation devices in high radiation areas may be verified by use of administrative means. Isolation devices that are locked, sealed, or otherwise secured may be verified by use of administrative means.
Deleted 400 additional hours is allowed for calendar year 2007 for operation of the containment ventilation system with purge isolation valves open.
October 11, 2005 SEQUOYAH - UNIT 2 3/4 6-15 Amendment No. 9, 109, 167, 207, 280, 290, 308 A1-17
CONTAINMENT SYSTEMS 3/4.6.3 CONTAINMENT ISOLATION VALVES LIMITING CONDITION FOR OPERATION Insert 3.6.3 Each containment isolation valve shall be OPERABLE.*
Notes APPLICABILITY: MODES 1, 2, 3 and 4.
Insert Notes ACTION:
Add a. With one or more penetration flow paths with one containment isolation valve inoperable; except exception for containment vacuum relief isolation valves(s), 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 /> for purge valves and by use of at least one closed deactivated automatic valve, closed manual valve, blind flange, or BYPASS check valve## with flow through the valve secured; and, verify# the affected penetration flow path LEAKAGE is isolated once per 31 days for isolation devices outside containment, and prior to entering PATHS TO MODE 4 from MODE 5 if not performed within the previous 92 days for isolation devices inside THE AUXILIARY containment.
BUILDING
- b. With one or more penetration flow paths with two containment isolation valves inoperable; except INSERT F for containment vacuum relief isolation valves(s), isolate each affected penetration within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> by use of at least one closed deactivated automatic valve, closed manual valve, or blind flange and verify# the affected penetration flow path is isolated once per 31 days.
- c. With one or more containment vacuum relief isolation valve(s) inoperable, the valve(s) must be returned to OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
Insert A dg. With any of the above ACTIONS not met, 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 />.
Insert SR SURVEILLANCE REQUIREMENTS Note Insert B 4.6.3.1 Deleted Relocated to
- 1. Penetration flow path(s) may be unisolated intermittently under administrative controls.
below LCO statement
- 2. Enter the ACTION of LCO 3.6.1.1, "Primary Containment" when containment isolation valve leakage results in exceeding the overall containment leakage rate acceptance criteria.
Relocated to
- 3. Isolation devices in high radiation areas may be verified by use of administrative means.
before the Action #4. Isolation devices that are locked, sealed, or otherwise secured may be verified by use of requirements administrative means.
- 5. A check valve with flow through the valve secured is only applicable to penetration flow paths with two containment isolation valves.
April 11, 2005 SEQUOYAH - UNIT 2 3/4 6-17 Amendment No. 193, 207, 245, 290 A1-18
CONTAINMENT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)
Removal of 4.6.3.2 Verify each automatic containment isolation valve that is not locked, sealed or otherwise excessive secured in position, actuates to the isolation position on an actual or simulated actuation signal, details. at least once per 18 months.Each automatic containment isolation valve shall be demonstrated OPERABLE 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 Containment Ventilation isolation test signal, each Containment Ventilation Isolation valve actuates to its isolation position.
- d. Verifying that on a high containment pressure isolation test signal, each Containment Vacuum Relief Valve actuates to its isolation position.
- e. Verifying that on a Safety Injection test signal that the Normal Charging Isolation valve actuates to its isolation position.
4.6.3.3 The isolation time of each power operated or automatic containment isolation valve shall be determined to be within its limit when tested pursuant to Specification 4.0.5.
4.6.3.4 Verify each containment isolation manual valve and blind flange that is located inside containment and not locked, sealed, or otherwise secured and required to be closed during accident conditions is closed, except for containment isolation valves that are open under administrative controls prior to entering Mode 4 from Mode 5 if not performed within the previous 92 days.*
4.6.3.5 Verify each containment isolation manual valve and blind flange that is located outside containment and not locked, sealed, or otherwise secured and required to be closed during accident conditions is closed, except for containment isolation valves that are open under administrative controls, at least once per 31 days.*
Insert C Relocated to before the
- NOTE: Valves and blind flanges in high radiation areas may be verified by use of SRs administrative means.
October 24, 2001 SEQUOYAH - UNIT 2 3/4 6-18 Amendment No. 72, 90, 104, 109, 193, 245, 260 A1-19
REFUELING OPERATIONS 3/4.9.4 CONTAINMENT BUILDING PENETRATIONS LIMITING CONDITION FOR OPERATION 3.9.4 The containment building penetrations shall be in the following status:
- a. The equipment door closed and held in place by a minimum of four bolts,
- b. A minimum of one door in each airlock is closed, or both doors of both containment personnel airlocks may be open if:
- 1. One personnel airlock door in each airlock is capable of closure, and
- 2. One train of the Auxiliary Building Gas Treatment System is OPERABLE in accordance with Technical Specification 3.9.12, and
- c. Each penetration* providing direct access from the containment atmosphere to the outside atmosphere shall be either:
- 1. Closed by an isolation valve, blind flange, manual valve, or equivalent, or
- 2. Be capable of being closed by an OPERABLE automatic Containment Ventilation isolation valve.
APPLICABILITY:
3.9.4.a. Containment Building Equipment Door - During movement of recently irradiated fuel within the containment.
3.9.4.b. and c. Containment Building Airlock Doors and Penetrations - During movement of irradiated fuel within the containment.
ACTION:
- 1. With the requirements of the above specification not satisfied for the containment building equipment door, immediately suspend all operations involving movement of recently irradiated fuel in the containment building. The provisions of Specification 3.0.3 are not applicable.
- 2. With the requirements of the above specification not satisfied for containment airlock doors or penetrations, immediately suspend all operations involving movement of irradiated fuel in the containment building. The provisions of Specification 3.0.3 are not applicable.
SURVEILLANCE REQUIREMENTS 4.9.4 Each of the above required containment building penetrations shall be determined to be either in its required condition or capable of being closed by an OPERABLE automatic Containment Ventilation isolation valve once per 7 days during movement of irradiated fuel in the containment building by:
Associated with removal
- a. Verifying the penetrations are in their required condition, or of excessive details in SR b. VerifyingTesting the Containment Ventilation isolation valves not locked, sealed, or 4.6.3.2. otherwise secured in position, actuate to the isolation position on an actual or simulated actuation signal.per the applicable portions of Specification 4.6.3.2.
- Penetration flow path(s) providing direct access from the containment atmosphere that transverse and terminate in the Auxiliary Building Secondary Containment Enclosure may be unisolated under administrative controls.
October 28, 2003 SEQUOYAH - UNIT 2 3/4 9-5 Amendment No. 199, 240, 251, 278 A1-20
ADMINISTRATIVE CONTROLS 6.8.4 f. Radioactive Effluent Controls Program (Cont.)
of radioactivity when the projected doses in a 31-day period would exceed 2 percent of the guidelines for the annual dose or dose commitment conforming to Appendix I to 10 CFR Part 50,
- 7) Limitations on the dose rate resulting from radioactive material released in gaseous effluents from the site to areas at or beyond the SITE BOUNDARY shall be in accordance with the following:
- 1. For noble gases: Less than or equal to a dose rate of 500 mrem/yr to the whole body and less than or equal to a dose rate of 3000 mrem/yr to the skin, and
- 2. For Iodine-131, Iodine-133, tritium, and for all radionuclides in particulate form with half-lives greater than 8 days: Less than or equal to a dose rate of 1500 mrem/year to any organ.
- 8) Limitations on the annual and quarterly air doses resulting from noble gases released in gaseous effluents from each unit to areas beyond the SITE BOUNDARY conforming to Appendix I to 10 CFR Part 50,
- 9) Limitations on the annual and quarterly doses to a member of the public from Iodine-131, Iodine-133, tritium, and all radio-nuclides in particulate form with half-lives greater than 8 days in gaseous effluents released from each unit to areas beyond the SITE BOUNDARY conforming to Appendix I to 10 CFR Part 50, and
- 10) Limitations on the annual dose or dose commitment to any member of the public, beyond the site boundary, due to releases of radioactivity and to radiation from uranium fuel cycle sources conforming to 40 CFR Part 190.
The provisions of SR 4.0.2 and 4.0.3 are applicable to the radioactive effluent controls program surveillance frequency.
- g. Radiological Environmental Monitoring Program (DELETED)
- h. Containment Leakage Rate Testing Program A program shall be established to implement the leakage rate testing of the containment as required by 10 CFR 50.54(o) and 10 CFR 50 Appendix J, Option B, as modified by approved exemptions. Visual examination and testing, including test intervals and extensions, shall be in accordance with Regulatory Guide (RG) 1.163, "Performance-Based Containment Leak-Test Program," dated September 1995 with exceptions provided in the Deleted Type A site implementing instructions and the following:. Performance of the spring 2003 extension containment integrated leakage rate (Type A) test may be deferred up to 5 years but no and add later than spring 2007.
Insert D The peak calculated containment internal pressure for the design basis loss of coolant accident, Pa, is 12.0 psig.
The maximum allowable containment leakage rate, La, at Pa, is 0.25% of the primary containment air weight per day.
Leakage rate acceptance criteria are:
- a. Containment overall leakage rate acceptance criteria is 1.0 La. During the first unit startup following testing in accordance with this program, the leakage rate acceptance criteria are 0.60 La for the combined Type B and Type C tests, and 0.75 La for Type A tests; May 29, 2003 SEQUOYAH - UNIT 2 6-9 Amendment No. 28, 50, 64, 66, 134, 165, 202, 207, 223, 265, 272, 276 A1-21
ADMINISTRATIVE CONTROLS
- b. Air lock testing acceptance criteria are:
- 1) Overall air lock leakage rate is 0.05 La when tested at Pa.
- 2) For each door, leakage rate is 0.01 La when pressurized to 6 psig for at least two minutes.
Insert E The provisions of SR 4.0.2 do not apply to the test frequencies specified in the Containment Leakage Rate Testing Program.
The provisions of SR 4.0.3 are applicable to the Containment Leakage Rate Testing Program.
- i. Configuration Risk Management Program (DELETED)
- j. Technical Specification (TS) Bases Control Program This program provides a means for processing changes to the Bases of these TSs.
- a. Changes to the Bases of the TS shall be made under appropriate administrative controls and reviews.
- b. Licensees may make changes to Bases without prior NRC approval provided the changes do not require either of the following:
- 1. A change in the TS incorporated in the license or
- 2. A change to the updated FSAR or Bases that requires NRC approval pursuant to 10 CFR 50.59.
- c. The Bases Control Program shall contain provisions to ensure that the Bases are maintained consistent with the FSAR.
- d. Proposed changes that meet the criteria of Specification 6.8.4.j.b above shall be reviewed and approved by the NRC prior to implementation. Changes to the Bases implemented without prior NRC approval shall be provided to the NRC on a frequency consistent with 10 CFR 50.71(e).
- k. Steam Generator (SG) Program A Steam Generator Program shall be established and implemented to ensure that SG tube integrity is maintained. In addition, the Steam Generator Program shall include the following provisions:
- a. Provisions for Condition Monitoring Assessments.
Condition monitoring assessment means an evaluation of the as found condition of the tubing with respect to the performance criteria for structural integrity and accident induced leakage. The as found condition refers to the condition of the tubing during an SG inspection outage, as determined from the inservice inspection results or by other means, prior to the plugging of tubes. Condition monitoring assessments shall be conducted during each outage during which the SG tubes are inspected or plugged, to confirm that the performance criteria are being met.
May 22, 2007 SEQUOYAH - UNIT 2 6-10 Amendment No. 28, 50, 64, 66, 134, 207, 223, 231, 271, 272, 298, 305 A1-22
ATTACHMENT 2 TENNESSEE VALLEY AUTHORITY SEQUOYAH NUCLEAR PLANT (SQN)
UNITS 1 AND 2 CHANGES TO TECHNICAL SPECIFICATIONS BASES PAGES I. AFFECTED PAGE LIST Unit 1 B 3/4 6-1 B 3/4 6-2 B 3/4 6-3 B 3/4 6-3a B 3/4 6-3b Unit 2 B 3/4 6-1 B 3/4 6-2 B 3/4 6-3 B 3/4 6-3a B 3/4 6-3b II. MARKED PAGES See attached.
A2-1
Bases Insert A1 Reactor Building Purge Ventilation (RBPV) System The RBPV System in part operates to supply outside air into the containment for ventilation and cooling or heating and may also be used to reduce the concentration of noble gases within containment prior to and during personnel access.
The RBPV System provides for mechanical ventilation of the primary containment, the instrument room located within the containment, and the annulus secondary containment located between primary containment and the Shield Building.
The RBPV System includes one supply duct penetration through the Shield Building wall into the annulus area. There are four purge air supply penetrations through the containment vessel, two to the upper compartment and two to the lower containment. Two normally closed 24-inch purge supply isolation valves at each penetration through the containment vessel provide containment isolation.
The RBPV System includes one exhaust duct penetration through the Shield Building wall from the annulus area. There are three purge air exhaust penetrations through the containment vessel, two from the upper compartment and one from the lower containment. There is one pressure relief penetration through the containment vessel. Two normally closed 24-inch purge exhaust isolation valves at each penetration through the containment vessel provide containment isolation. Two normally closed 8-inch pressure relief isolation valves through the containment vessel provide containment isolation.
The RBPV System includes one supply and one exhaust duct penetration through the Shield Building wall and one supply and one exhaust duct penetration through the containment vessel wall for ventilation of the instrument room inside containment. Two normally closed 12-inch purge isolation valves at each supply and exhaust penetration through the containment vessel provide containment isolation.
Bases Insert B1 Additional valves have been identified as barrier valves, which in addition to the containment isolation valves discussed above, are a part of the accident monitoring instrumentation in Technical Specification 3/4.3.3.7 and are designated as Category 1 in accordance with Regulatory Guide 1.97, Revision 2, "Instrumentation for Light-Water-Cooled Nuclear Power Plants to Assess Plant Conditions During and Following an Accident," December 1980.
Bases Insert C1 Providing instruction to the operator to close these valves in an accident situation, and assuring that the environmental conditions will not preclude access to close the valves and that this action will prevent the release of radioactivity outside the containment. For valves with controls located in the control room, these conditions can be satisfied by including a specific reference to closing the particular valves in the emergency procedures, since communication and environmental factors are not affected because of the location of the valve controls.
Bases Insert D1 Note that due to competing requirements and dual functions associated with the containment vacuum relief isolation valves (FCV-30-46, -47, and -48), the air supply and solenoid arrangement is designed such that upon the unavailability of Train A essential control air, the containment vacuum relief isolation valves are incapable of automatic closure and are therefore considered inoperable for the containment isolation function without operator action.
The containment vacuum relief valves (30-571, -572, and -573) are qualified to perform a containment isolation function. These valves are not powered from any electrical source and no spurious signal or operator action could initiate opening. The valves are spring loaded, swing disk (check) valves with an elastomer seat. The valves are normally closed and are equipped with limit switches that provide fully A2-2
open and fully closed indication in the main control room (MCR). Based upon the above information, a 72-hour allowed action time is appropriate while actions are taken to return the containment vacuum relief isolation valves to service.
A2-3
3/4.6 CONTAINMENT SYSTEMS BASES 3/4.6.1 PRIMARY CONTAINMENT The safety design basis for primary containment is that the containment must withstand the pressures and temperatures of the limiting design basis accident (DBA) without exceeding the design leakage rates.
The DBAs that result in a challenge to containment OPERABILITY from high pressures and temperatures are a loss of coolant accident (LOCA), a steam line break, and a rod ejection accident (REA). In addition, release of significant fission product radioactivity within containment can occur from a LOCA or REA. In the DBA analyses, it is assumed that the containment is OPERABLE such that, for the DBAs involving release of fission product radioactivity, release to the environment is controlled by the rate of containment leakage. This leakage rate limitation will limit the site boundary radiation doses to within the limits of 10 CFR 100 during accident conditions. The containment was designed with an allowable leakage rate of 0.25 percent of containment air weight per day. This leakage rate, used in the evaluation of offsite doses resulting from accidents, is defined in the Containment Leakage Rate Test Program, as La: the maximum allowable containment leakage rate at the calculated peak containment internal pressure (Pa) resulting from the limiting DBA. The allowable leakage rate represented by La forms the basis for the acceptance criteria imposed on all containment leakage rate testing.
Primary containment INTEGRITY or operability is maintained by limiting leakage to within the acceptance criteria of the Containment Leakage Rate Test Program.
3/4.6.1.2 SECONDARY CONTAINMENT BYPASS LEAKAGE The safety design basis for containment leakage assumes that 75 percent of the leakage from the primary containment enters the shield building annulus for filtration of the emergency gas treatment system. The remaining 25 percent of the primary containment leakage, which is considered to be bypassed to the auxiliary building, is assumed to exhaust directly to the atmosphere without filtration during the first 5 minutes of the accident. After 5 minutes, any bypass leakage to the auxiliary building is filtered by the auxiliary building gas treatment system. A tabulation of potential secondary containment bypass This specification has been relocated.
February 5, 1996 SEQUOYAH - UNIT 1 B 3/4 6-1 Amendment No. 102, 127, 176, 217 A2-4
3/4.6 CONTAINMENT SYSTEMS BASES leakage paths to the auxiliary building is provided in the Containment Leakage Rate Test Program.
Restricting the leakage through the bypass leakage paths to 0.25 La provides assurance that the leakage fraction assumptions used in the evaluation of site boundary radiation doses remain valid.
3/4.6.1.3 CONTAINMENT AIR LOCKS The limitations on closure and leak rate for the containment air locks are required to meet the restrictions on CONTAINMENT INTEGRITY and containment leak rate. Surveillance testing of the air lock seals provide assurance that the overall air lock leakage will not become excessive due to seal damage during the intervals between air lock leakage tests.
3/4.6.1.4 INTERNAL PRESSURE The limitations on containment internal pressure ensure that 1) the containment structure is prevented from exceeding its design negative pressure differential with respect to the annulus atmosphere of 0.5 psig and 2) the containment peak pressure does not exceed the maximum allowable internal pressure of 12 psig during LOCA conditions.
3/4.6.1.5 AIR TEMPERATURE The limitations on containment average air temperature ensure that 1) the containment air mass is limited to an initial mass sufficiently low to prevent exceeding the maximum allowable internal pressure during LOCA conditions and 2) the ambient air temperature does not exceed that temperature allowable for the continuous duty rating specified for equipment and instrumentation located within containment.
The containment pressure transient is sensitive to the initially contained air mass during a LOCA.
The contained air mass increases with decreasing temperature. The lower temperature limits of 100°F for the lower compartment, 85°F for the upper compartment, and 60°F when less than or equal to 5% of RATED THERMAL POWER will limit the peak pressure to an acceptable value. The upper temperature limit influences the peak accident temperature slightly during a LOCA; however, this limit is based primarily upon equipment protection and anticipated operating conditions. Both the upper and lower temperature limits are consistent with the parameters used in the accident analyses.
3/4.6.1.6 CONTAINMENT VESSEL STRUCTURAL INTEGRITY This limitation ensures that the structural integrity of the containment steel vessel will be maintained comparable to the original design standards for the life of the facility. Structural integrity is required to ensure that the vessel will withstand the maximum pressure of 12 psig in the event of a LOCA.
Periodic visual inspections in accordance with the Containment Leakage Rate Test Program are sufficient to demonstrate this capability.
February 5, 1996 SEQUOYAH - UNIT 1 B 3/4 6-2 Amendment No. 102, 127, 176, 203, 217 A2-5
CONTAINMENT SYSTEMS BASES 3/4.6.1.8 EMERGENCY GAS TREATMENT SYSTEM (EGTS)
The OPERABILITY of the EGTS cleanup subsystem ensures that during LOCA conditions, containment vessel leakage into the annulus will be filtered through the HEPA filters and charcoal adsorber trains prior to discharge to the atmosphere. This requirement is necessary to meet the assumptions used in the accident analyses and limit the site boundary radiation doses to within the limits of 10 CFR 100 during LOCA conditions. Cumulative operation of the system with the heaters on for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> over a 31 day period is sufficient to reduce the buildup of moisture on the absorbers and HEPA filters. ANSI N510-1975 will be used as a procedural guide for surveillance testing.
3/4.6.1.9 CONTAINMENT VENTILATION SYSTEM Use of the containment purge lines is restricted to only one pair (one supply line and one exhaust line) of purge system lines at a time to ensure that the site boundary dose guidelines of 10 CFR Part 100 would not be exceeded in the event of a loss of coolant accident during purging operations. The analysis of this accident assumed purging through the largest pair of lines (a 24 inch inlet line and a 24 inch outlet line), a pre-existing iodine spike in the reactor coolant and four second valve closure times.
This specification has been relocated.
3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS 3/4.6.2.1 CONTAINMENT SPRAY SUBSYSTEMS The OPERABILITY of the containment spray subsystems ensures that containment depressurization and cooling capability will be available in the event of a LOCA. The pressure reduction and resultant lower containment leakage rate are consistent with the assumptions used in the accident analyses.
3/4.6.2.2 CONTAINMENT COOLING FANS The OPERABILITY of the lower containment vent coolers ensures that adequate heat removal capacity is available to provide long-term cooling following a non-LOCA event. Postaccident use of these coolers ensures containment temperatures remain within environmental qualification limits for all safety-related equipment required to remain functional.
3/4.6.3 CONTAINMENT ISOLATION VALVES The operability of the containment isolation valves ensures that the containment atmosphere will be isolated from the outside environment in the event of a release of radioactive material to the containment atmosphere or pressurization of the containment. Containment isolation within the time Insert limits specified ensures that the release of radioactive material to the environment will be consistent with Standard the assumptions used in the analyses for a loss of coolant accident.
Bases Additional valves have been identified as barrier valves, which in addition to the containment isolation valves discussed above, are a part of the accident monitoring instrumentation in Technical Specification 3/4.3.3.7 and are designated as Category 1 in accordance with Regulatory Guide 1.97, Revision 2, "Instrumentation for Light-Water-Cooled Nuclear Power Plants to Assess Plant Conditions During and Following an Accident," December 1980.
June 13, 1995 SEQUOYAH - UNIT 1 B 3/4 6-3 Amendment No. 67, 114, 150, 159, 203 A2-6
CONTAINMENT SYSTEMS 3/4.6.3 CONTAINMENT ISOLATION VALVES (Continued)
BASES The opening of penetration flow path(s) on an intermittent basis under administrative control includes the following considerations: (1) stationing an operator, who is in constant communication with the control room, at the valve controls, (2) instructing the operator to close these valves in an accident situation, and (3) assuring that the environmental conditions will not preclude access to close the valves and that this action will prevent the release of radioactivity outside the containment. For valves with controls located in the control room, these conditions can be satisfied by including a specific reference to closing the particular valves in the emergency procedures, since communication and environmental factors are not affected because of the location of the valve controls.
Note that due to competing requirements and dual functions associated with the containment vacuum relief isolation valves (FCV-30-46, -47, and -48), the air supply and solenoid arrangement is designed such that upon the unavailability of Train A essential control air, the containment vacuum relief isolation valves are incapable of automatic closure and are therefore considered inoperable for the containment isolation function without operator action.
The containment vacuum relief valves (30-571, -572, and -573) are qualified to perform a containment isolation function. These valves are not powered from any electrical source and no spurious Insert Standard signal or operator action could initiate opening. The valves are spring loaded, swing disk (check) valves Bases with an elastomer seat. The valves are normally closed and are equipped with limit switches that provide fully open and fully closed indication in the main control room (MCR). Based upon the above information, a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowed action time is appropriate while actions are taken to return the containment vacuum relief isolation valves to service.
Isolation of a containment penetration flow path may include the use of a check valve with flow through the valve secured. This method of isolation would involve stopping flow through the penetration flow path such that the check valve acts as a containment isolation barrier.
Surveillance Requirement 4.6.3.4 This SR requires verification that each containment isolation manual valve and blind flange located inside containment and not locked, sealed, or otherwise secured and required to be closed during accident conditions is closed. The SR helps to ensure that post accident leakage of radioactive fluids or gases outside of the containment boundary is within design limits. For containment isolation valves inside containment, the Frequency of prior to entering Mode 4 from Mode 5 if not performed within the previous 92 days is appropriate since these containment isolation valves are operated under administrative controls and the probability of their misalignment is low. The SR specifies that containment isolation valves that are open under administrative controls are not required to meet the SR during the time they are open. This SR does not apply to valves that are locked, sealed, or otherwise secured in the closed position, since these were verified to be in the correct position upon locking, sealing, or securing.
This Note allows valves and blind flanges located in high radiation areas to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since access to these areas is typically restricted during Modes 1, 2, 3, and 4 for ALARA reasons. Therefore, the probability of misalignment of these containment isolation valves, once they have been verified to be in their proper position, is small.
October 24, 2001 SEQUOYAH - UNIT 1 B 3/4 6-3a Amendment No. 197, 203, 254, 271 A2-7
CONTAINMENT SYSTEMS 3/4.6.3 CONTAINMENT ISOLATION VALVES (Continued)
BASES Surveillance Requirement 4.6.3.5 This SR requires verification that each containment isolation manual valve and blind flange located outside containment and not locked, sealed, or otherwise secured and required to be closed during accident conditions is closed. The SR helps to ensure that post accident leakage of radioactive fluids or gases outside of the containment boundary is within design limits. This SR does not require any testing or valve manipulation. Rather, it involves verification that those containment isolation valves outside containment and capable of being mispositioned are in the correct position. Since verification of valve position for containment isolation valves outside containment is relatively easy, the 31 day Frequency is Insert Standard based on engineering judgment and was chosen to provide added assurance of the correct positions.
Bases The SR specifies that containment isolation valves that are open under administrative controls are not required to meet the SR during the time the valves are open. This SR does not apply to valves that are locked, sealed, or otherwise secured in the closed position, since these were verified to be in the correct position upon locking, sealing, or securing.
This Note applies to valves and blind flanges located in high radiation areas and allows these devices to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since access to these areas is typically restricted during Modes 1, 2, 3, and 4 for ALARA reasons. Therefore, the probability of misalignment of these containment isolation valves, once they have been verified to be in their proper position, is small.
June 26, 2003 SEQUOYAH - UNIT 1 B 3/4 6-3b Amendment No. 197, 203, 254, 271 A2-8
3/4.6 CONTAINMENT SYSTEMS BASES 3/4.6.1 PRIMARY CONTAINMENT The safety design basis for primary containment is that the containment must withstand the pressures and temperatures of the limiting design basis accident (DBA) without exceeding the design leakage rates.
The DBAs that result in a challenge to containment OPERABILITY from high pressures and temperatures are a loss of coolant accident (LOCA), a steam line break, and a rod ejection accident (REA). In addition, release of significant fission product radioactivity within containment can occur from a LOCA or REA. In the DBA analyses, it is assumed that the containment is OPERABLE such that, for the DBAs involving release of fission product radioactivity, release to the environment is controlled by the rate of containment leakage. This leakage rate limitation will limit the site boundary radiation doses to within the limits of 10 CFR 100 during accident conditions. The containment was designed with an allowable leakage rate of 0.25 percent of containment air weight per day. This leakage rate, used in the evaluation of offsite doses resulting from accidents, is defined in the Containment Leakage Rate Test Program, as La: the maximum allowable containment leakage rate at the calculated peak containment internal pressure (Pa) resulting from the limiting DBA. The allowed leakage rate represented by La forms the basis for the acceptance criteria imposed on all containment leakage rate testing.
Primary containment INTEGRITY or operability is maintained by limiting leakage to within the acceptance criteria of the Containment Leakage Rate Test Program.
3/4.6.1.2 SECONDARY CONTAINMENT BYPASS LEAKAGE The safety design basis for containment leakage assumes that 75 percent of the leakage from the primary containment enters the shield building annulus for filtration by the emergency gas treatment system. The remaining 25 percent of the primary containment leakage, which is considered to be bypassed to the auxiliary building, is assumed to exhaust directly to the atmosphere without filtration during the first 5 minutes of the accident. After 5 minutes, any bypass leakage to the auxiliary building is filtered by the auxiliary building gas treatment system. A tabulation of potential secondary containment bypass This specification has been relocated February 5, 1996 SEQUOYAH - UNIT 2 B 3/4 6-1 Amendment Nos. 91, 139, 167, 207 A2-9
3/4.6 CONTAINMENT SYSTEMS BASES leakage paths to the auxiliary building is provided in the Containment Leakage Rate Test Program.
Restricting the leakage through the bypass leakage paths to 0.25 La provides assurance that the leakage fraction assumptions used in the evaluation of site boundary radiation doses remain valid.
3/4.6.1.3 CONTAINMENT AIR LOCKS The limitations on closure and leak rate for the containment air locks are required to meet the restrictions on CONTAINMENT INTEGRITY and containment leak rate. Surveillance testing of the air lock seals provide assurance that the overall air lock leakage will not become excessive due to seal damage during the intervals between air lock leakage tests.
3/4.6.1.4 INTERNAL PRESSURE The limitations on containment internal pressure ensure that 1) the containment structure is prevented from exceeding its design negative pressure differential with respect to the annulus atmosphere of 0.5 psig and 2) the containment peak pressure does not exceed the maximum allowable internal pressure of 12 psig during LOCA conditions.
3/4.6.1.5 AIR TEMPERATURE The limitations on containment average air temperature ensure that 1) the containment air mass is limited to an initial mass sufficiently low to prevent exceeding the maximum allowable internal pressure during LOCA conditions and 2) the ambient air temperature does not exceed that temperature allowable for the continuous duty rating specified for equipment and instrumentation located within containment.
The containment pressure transient is sensitive to the initially contained air mass during a LOCA.
The contained air mass increases with decreasing temperature. The lower temperature limits of 100°F for the lower compartment, 85°F for the upper compartment, and 60°F when less than or equal to 5% of RATED THERMAL POWER will limit the peak pressure to an acceptable value. The upper temperature limit influences the peak accident temperature slightly during a LOCA; however, this limit is based primarily upon equipment protection and anticipated operating conditions. Both the upper and lower temperature limits are consistent with the parameters used in the accident analyses.
3/4.6.1.6 CONTAINMENT VESSEL STRUCTURAL INTEGRITY This limitation ensures that the structural integrity of the containment steel vessel will be maintained comparable to the original design standards for the life of the facility. Structural integrity is required to ensure that the vessel will withstand the maximum pressure of 12 psig in the event of a LOCA.
Periodic visual inspections in accordance with the Containment Leakage Rate Test Program are sufficient to demonstrate this capability.
February 5, 1996 SEQUOYAH - UNIT 2 B 3/4 6-2 Amendment No. 91, 139, 167, 193, 207 A2-10
CONTAINMENT SYSTEMS BASES 3/4.6.1.8 EMERGENCY GAS TREATMENT SYSTEM (EGTS)
The OPERABILITY of the EGTS cleanup subsystem ensures that during LOCA conditions, containment vessel leakage into the annulus will be filtered through the HEPA filters and charcoal adsorber trains prior to discharge to the atmosphere. This requirement is necessary to meet the assumptions used in the accident analyses and limit the site boundary radiation doses to within the limits of 10 CFR l00 during LOCA conditions. Cumulative operation of the system with the heaters on for 10 hours1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> over a 31 day period is sufficient to reduce the buildup of moisture on the absorbers and HEPA filters. ANSI N510-1975 will be used as a procedural guide for surveillance testing.
3/4.6.1.9 CONTAINMENT VENTILATION SYSTEM Use of the containment purge lines is restricted to only one pair (one supply line and one exhaust line) of purge system lines at a time to ensure that the site boundary dose guidelines of 10 CFR Part 100 would not be exceeded in the event of a loss of coolant accident during purging operations. The analysis of this accident assumed purging through the largest pair of lines (a 24 inch inlet line and a 24 inch outlet line), a pre-existing iodine spike in the reactor coolant and four second valve closure times.
This specification has been relocated 3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS 3/4.6.2.1 CONTAINMENT SPRAY SUBSYSTEMS The OPERABILITY of the containment spray subsystems ensures that containment depressurization and cooling capability will be available in the event of a LOCA. The pressure reduction and resultant lower containment leakage rate are consistent with the assumptions used in the accident analyses.
3/4.6.2.2 CONTAINMENT COOLING FANS The OPERABILITY of the lower containment vent coolers ensures that adequate heat removal capacity is available to provide long-term cooling following a non-LOCA event. Postaccident use of these coolers ensures containment temperatures remain within environmental qualification limits for all safety-related equipment required to remain functional.
3/4.6.3 CONTAINMENT ISOLATION VALVES The operability of containment isolation valves ensures that the containment atmosphere will be isolated from the outside environment in the event of a release of radioactive material to the containment atmosphere or pressurization of the containment. Containment isolation within the time limits specified ensures that the release of radioactive material to the environment will be consistent with the assumptions used to the analyses for a loss of coolant accident.
Insert Standard Additional valves have been identified as barrier valves, which in addition to the containment isolation Bases valves discussed above, are a part of the accident monitoring instrumentation in Technical Specification 3/4.3.3.7 and are designated as Category 1 in accordance with Regulatory Guide 1.97, Revision 2, "Instrumentation for Light-Water-Cooled Nuclear Power Plants to Assess Plant Conditions During and Following an Accident," December 1980.
June 13, 1995 SEQUOYAH - UNIT 2 B 3/4 6-3 Amendment No. 59, 140, 149, 193 A2-11
CONTAINMENT SYSTEMS BASES 3/4.6.3 CONTAINMENT ISOLATION VALVES (Continued The opening of penetration flow path(s) on an intermittent basis under administrative control includes the following considerations: (1) stationing an operator, who is in constant communication with the control room, at the valve controls, (2) instructing the operator to close these valves in an accident situation, and (3) assuring that the environmental conditions will not preclude access to close the valves and that this action will prevent the release of radioactivity outside the containment. For valves with controls located in the control room, these conditions can be satisfied by including a specific reference to closing the particular valves in the emergency procedures, since communication and environmental factors are not affected because of the location of the valve controls.
Note that due to competing requirements and dual functions associated with the containment vacuum relief isolation valves (FCV-30-46, -47, and -48), the air supply and solenoid arrangement is designed such that upon the unavailability of Train A essential control air, the containment vacuum relief isolation valves are incapable of automatic closure and are therefore considered inoperable for the containment isolation function without operator action.
The containment vacuum relief valves (30-571, -572, and -573) are qualified to perform a containment isolation function. These valves are not powered from any electrical source and no spurious signal or operator action could initiate opening. The valves are spring loaded, swing disk (check) valves with an elastomer seat. The valves are normally closed and are equipped with limit switches that provide fully open and fully closed indication in the main control room (MCR). Based upon the above information, a 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowed action time is appropriate while actions are taken to return the containment vacuum relief isolation valves to service.
Isolation of a containment penetration flow path may include the use of a check valve with flow Insert through the valve secured. This method of isolation would involve stopping flow through the penetration Standard flow path such that the check valve acts as a containment isolation barrier.
Bases Surveillance Requirement 4.6.3.4 This SR requires verification that each containment isolation manual valve and blind flange located inside containment and not locked, sealed, or otherwise secured and required to be closed during accident conditions is closed. The SR helps to ensure that post accident leakage of radioactive fluids or gases outside of the containment boundary is within design limits. For containment isolation valves inside containment, the Frequency of prior to entering Mode 4 from Mode 5 if not performed within the previous 92 days is appropriate since these containment isolation valves are operated under administrative controls and the probability of their misalignment is low. The SR specifies that containment isolation valves that are open under administrative controls are not required to meet the SR during the time they are open. This SR does not apply to valves that are locked, sealed, or otherwise secured in the closed position, since these were verified to be in the correct position upon locking, sealing, or securing.
This Note allows valves and blind flanges located in high radiation areas to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since access to these areas is typically restricted during Modes 1, 2, 3, and 4 for ALARA reasons. Therefore, the probability of misalignment of these containment isolation valves, once they have been verified to be in their proper position, is small.
Surveillance Requirement 4.6.3.5 This SR requires verification that each containment isolation manual valve and blind flange located outside containment and not locked, sealed, or otherwise secured and required to be closed during accident conditions is closed. The SR helps to ensure that post accident leakage of radioactive fluids or October 24, 2001 SEQUOYAH - UNIT 2 B 3/4 6-3a Amendment No. 188, 193, 245, 260 A2-12
CONTAINMENT SYSTEMS 3/4.6.3 CONTAINMENT ISOLATION VALVES (Continued)
BASES gases outside of the containment boundary is within design limits. This SR does not require any testing or valve manipulation. Rather, it involves verification that those containment isolation valves outside containment and capable of being mispositioned are in the correct position. Since verification of valve position for containment isolation valves outside containment is relatively easy, the 31 day Frequency is based on engineering judgment and was chosen to provide added assurance of the correct positions.
The SR specifies that containment isolation valves that are open under administrative controls are not required to meet the SR during the time the valves are open. This SR does not apply to valves that are Insert Standard locked, sealed, or otherwise secured in the closed position, since these were verified to be in the correct Bases position upon locking, sealing, or securing.
This Note applies to valves and blind flanges located in high radiation areas and allows these devices to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since access to these areas is typically restricted during Modes 1, 2, 3, and 4 for ALARA reasons. Therefore, the probability of misalignment of these containment isolation valves, once they have been verified to be in their proper position, is small.
June 26, 2003 SEQUOYAH - UNIT 2 B 3/4 6-3b Amendment No. 188, 193, 245, 260 A2-13
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 B 3.6 CONTAINMENT SYSTEMS B 3.6.3 Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
BASES BACKGROUND 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 or which are normally closed. These isolation devices are either passive or active (automatic). Manual valves, de-activated automatic valves secured in their closed position (including check valves with flow through the valve secured), blind flanges, and closed systems are considered passive devices. Check valves, or other automatic valves designed to close without operator action following an accident, are considered active devices. Two barriers in series are provided for each penetration or an approved exemption is provided 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. These barriers (typically containment isolation valves) make up the Containment Isolation System.
Automatic isolation signals are produced during accident conditions.
Containment Phase "A" isolation occurs upon receipt of a safety injection signal.
The Phase "A" isolation signal isolates nonessential process lines in order to minimize leakage of fission product radioactivity. Containment Phase "B" isolation occurs upon receipt of a containment pressure High-High signal and isolates the remaining process lines, except systems required for accident mitigation. In addition to the isolation signals listed above, the purge and exhaust valves receive an isolation signal on a containment high radiation condition. As a result, the containment isolation valves (and blind flanges) help ensure that the containment atmosphere will be isolated from the environment in the event of a release of fission product radioactivity to the containment atmosphere as a result of a Design Basis Accident (DBA).
The OPERABILITY requirements for containment isolation valves help ensure that containment is isolated within the time limits assumed in the safety analyses.
Therefore, the OPERABILITY requirements provide assurance that the containment function assumed in the safety analyses will be maintained.
SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-1 Rev. 3.0, 03-31-04 A2-14
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES BACKGROUND (continued)
Shutdown Purge System ([42] inch purge valves)Reactor Building Purge Ventilation (RBPV) System The Shutdown Purge System operates to supply outside air into the containment Bases Insert A1 for ventilation and cooling or heating and may also be used to reduce the concentration of noble gases within containment prior to and during personnel access. The supply and exhaust lines each contain two isolation valves.
Because of their large size, the [42] inch purge valves in some units are not qualified for automatic closure from their open position under DBA conditions.
Therefore, the [42] inch purge valves are normally maintained closed in MODES 1, 2, 3, and 4 to ensure the containment boundary is maintained.
Minipurge System ([8] inch purge valves)
The Minipurge System operates to:
- a. Reduce the concentration of noble gases within containment prior to and during personnel access and
- b. Equalize internal and external pressures.
Since the valves used in the Minipurge RBPV System are designed to meet the requirements for automatic containment isolation valves, these valves may be opened as needed in MODES 1, 2, 3, and 4.
APPLICABLE The containment isolation valve LCO was derived from the assumptions SAFETY related to minimizing the loss of reactor coolant inventory and ANALYSES establishing the containment boundary during major accidents. As part of the containment boundary, containment isolation valve OPERABILITY supports leak tightness of the containment. Therefore, the safety analyses of any event requiring isolation of containment is applicable to this LCO.
The DBAs that result in a release of radioactive material within containment are a loss of coolant accident (LOCA) and a rod ejection accident (Ref. 1). In the analyses for each of these accidents, it is assumed that containment isolation valves are either closed or function to close within the required isolation time following event initiation. This ensures that potential paths to the environment through containment isolation valves (including containment purge valves) are minimized. The safety analyses assume that the [42] inch purge valves are closed at event initiation.
SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-2 Rev. 3.0, 03-31-04 A2-15
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES APPLICABLE SAFETY ANALYSES (continued)
The DBA analysis assumes that, within 60 85 seconds after the accident, isolation of the containment is complete and leakage terminated except for the design leakage rate, La. The containment isolation total response time of 60 85 seconds includes signal delay, diesel generator startup (for loss of offsite power),
and containment isolation valve stroke times.
[ The single failure criterion required to be imposed in the conduct of plant safety analyses was considered in the original design of the containment purge valves.
Two valves in series on each purge line provide assurance that both the supply and exhaust lines could be isolated even if a single failure occurred. The inboard and outboard isolation valves on each line are provided with diverse power sources, motor operated and pneumatically operated to open and spring closed, respectively. This arrangement was designed to preclude common mode failures from disabling both valves on a purge line. ]
[ The purge valves may be unable to close in the environment following a LOCA.
Therefore, each of the purge valves is required to remain sealed closed during MODES 1, 2, 3, and 4. In this case, the single failure criterion remains applicable Bases Insert B1 to the containment purge valves due to failure in the control circuit associated with each valve. Again, the purge system valve design precludes a single failure from compromising the containment boundary as long as the system is operated in accordance with the subject LCO. ]
The containment isolation valves satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LCO Containment isolation valves form a part of the containment boundary. The containment isolation valves' safety function is related to minimizing the loss of reactor coolant inventory and establishing the containment boundary during a DBA.
The automatic power operated isolation valves are required to have isolation times within limits and to actuate on an automatic isolation signal. The [42]
inchcontainment isolation purge valves must be maintained sealed closed [or have blocks installed to prevent full opening]. [Blocked purge valves also actuate on an automatic signal.] The valves covered by this LCO are listed along with their associated stroke times in the FSAR (Ref. 2).
SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-3 Rev. 3.0, 03-31-04 A2-16
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES LCO (continued)
The normally closed isolation valves are considered OPERABLE when manual valves are closed, automatic valves are de-activated and secured in their closed position, and blind flanges are in place, and closed systems are intact. These passive isolation valves/devices are those listed in Reference 2.
Purge valves with resilient seals [and secondary containment bypass BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDINGvalves] must meet additional leakage rate requirements. The other containment isolation valve leakage rates are addressed by LCO 3.6.1, "Primary Containment," as Type C testing.
This LCO provides assurance that the containment isolation valves and purge valves will perform their designed safety functions to minimize the loss of reactor coolant inventory and establish the containment boundary during accidents.
The LCO is modified by two Notes. The first Note directs entry into the applicable required Actions of LCO 3.6.1, in the event the isolation valve leakage results in exceeding the overall containment leakage rate.
A second Note is added allowing penetration flow paths to be unisolated intermittently under administrative controls. These administrative controls consist of stationing a dedicated operator at the valve controls, who is in continuous communication with the control room. In this way, the Bases Insert C1 penetration can be rapidly isolated when a need for containment isolation is indicated.
APPLICABILITY In MODES 1, 2, 3, and 4, a DBA could cause a release of radioactive material to containment. In MODES 5 and 6, the probability and consequences of these events are reduced due to the pressure and temperature limitations of these MODES. Therefore, the containment isolation valves are not required to be OPERABLE in MODE 5. The requirements for containment isolation valves during MODE 6 are addressed in LCO 3.9.4, "Containment Building Penetrations."
ACTIONS The ACTIONS are modified by a Note allowing penetration flow paths, except for
[42] inch purge valve penetration flow paths, to be unisolated intermittently under administrative controls. These administrative controls consist of stationing a dedicated operator at the valve controls, who is in continuous communication with the control room. In this way, the penetration can be rapidly isolated when a need for containment isolation is indicated. Due to the size of the containment purge line penetration and the fact that those penetrations exhaust directly from the containment atmosphere to the environment, the penetration flow path containing these valves may not be opened under administrative controls. A single purge valve in a penetration flow path may be opened to effect repairs to an inoperable valve, as allowed by SR 3.6.3.1.
SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-4 Rev. 3.0, 03-31-04 A2-17
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES ACTIONS (continued)
A second Note has been added to provide clarification that, for this LCO, separate Condition entry is allowed for each penetration flow path. This is acceptable, since the Required Actions for each Condition provide appropriate compensatory actions for each inoperable containment isolation valve.
Complying with the Required Actions may allow for continued operation, and subsequent inoperable containment isolation valves are governed by subsequent Condition entry and application of associated Required Actions.
The ACTIONS are further modified by a third Note, which ensures appropriate remedial actions are taken, if necessary, if the affected systems are rendered inoperable by an inoperable containment isolation valve.
In the event the isolation valve leakage results in exceeding the overall containment leakage rate, Note 4 directs entry into the applicable Conditions and Required Actions of LCO 3.6.1.
A.1 and A.2 a.
In the event one containment isolation valve in one or more penetration flow paths is inoperable, [except for containment vacuum relief isolation valve(s),
and purge valve or secondary containment BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDINGshield building bypass leakage not within limit], the affected penetration flow path must be isolated. The method of isolation must include the use of at least one isolation barrier that cannot be adversely affected by a single active failure. Isolation barriers that meet this criterion are a closed and deactivated automatic containment isolation valve, a closed manual valve, a blind flange, and a check valve with flow through the valve secured. For a penetration flow path isolated in accordance with this Required required Action A.1, the device used to isolate the penetration should be the closest available one to containment. This Required required Action A.1 must be completed within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> Completion completion Time time is reasonable, considering the time required to isolate the penetration and the relative importance of supporting containment OPERABILITY during MODES 1, 2, 3, and 4.
For affected penetration flow paths that cannot be restored to OPERABLE status within the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> Completion completion Time time and that have been isolated in accordance with this Required required Action A.1, the affected penetration flow paths must be verified to be isolated on a periodic basis. This is necessary to ensure that containment penetrations required to be isolated following an accident and no longer capable of being automatically isolated will be in the SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-5 Rev. 3.0, 03-31-04 A2-18
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES ACTIONS (continued) isolation position should an event occur. This Required required Action does not require any testing or device manipulation. Rather, it involves verification that those isolation devices outside containment and capable of being mispositioned are in the correct position. The Completion Time A Frequency of "once per 31 days for isolation devices outside containment" is appropriate considering the fact that the devices are operated under administrative controls and the probability of their misalignment is low. For the isolation devices inside containment, the time period specified as "prior to entering MODE 4 from MODE 5 if not performed within the previous 92 days" is based on engineering judgment and is considered reasonable in view of the inaccessibility of the isolation devices and other administrative controls that will ensure that isolation device misalignment is an unlikely possibility.
Condition A has been modified by a Note indicating that this Condition is only applicable to those penetration flow paths with two [or more] containment isolation valves. For penetration flow paths with only one containment isolation valve and a closed system, Condition C provides the appropriate actions.
Required Action A.2a. is modified by twothree Notes. One of the Notes 1 applies to isolation devices located in high radiation areas and allows these devices to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since access to these areas is typically restricted. Note 2The second Note applies to isolation devices that are locked, sealed, or otherwise secured in position and allows these devices to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since the function of locking, sealing, or securing components is to ensure that these devices are not inadvertently repositioned. Therefore, the probability of misalignment of these devices once they have been verified to be in the proper position, is small.
The third Note provides clarification that use of a check valve with flow through the valve secured is only applicable to penetration flow paths with two containment isolation valves.
B.1 b.
With two [or more] containment isolation valves in one or more penetration flow paths inoperable, [except for containment vacuum relief isolation valve(s),
and purge valve or shield building bypass leakage not within limit,] the affected penetration flow path must be isolated within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. The method of isolation must include the use of at least one isolation barrier that cannot be adversely affected by a single active failure. Isolation barriers that meet this criterion are a SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-6 Rev. 3.0, 03-31-04 A2-19
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES ACTIONS (continued) closed and de-activated automatic valve, a closed manual valve, and a blind flange. The 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Completion completion Time time is consistent with the Actions of LCO 3.6.1. In the event the affected penetration is isolated in accordance with this Required required Action B.1, the affected penetration must be verified to be isolated on a periodic basis per Required Action A.2, which remains in effect. This periodic verification is necessary to assure leak tightness of containment and that penetrations requiring isolation following an accident are isolated. The Completion Time A Frequency of once per 31 days for verifying each affected penetration flow path is isolated is appropriate considering the fact that the valves are operated under administrative control and the probability of their misalignment is low.
Condition B is modified by a Note indicating this Condition is only applicable to penetration flow paths with two [or more] containment isolation valves. Condition A of this LCO addresses the condition of one containment isolation valve inoperable in this type of penetration flow path. Required Action b. is modified by two Notes. One of the Notes applies to isolation devices located in high-radiation areas and allows these devices to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since access to these areas is typically restricted.
The second Note applies to isolation devices that are locked, sealed, or otherwise secured in position and allows these devices to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since the function of locking, sealing, or securing components is to ensure that these devices are not inadvertently repositioned. Therefore, the probability of misalignment of these devices once they have been verified to be in the proper position is small.
C.1 and C.2 c.
With one or more penetration flow paths with one containment vacuum relief isolation valve inoperable, the inoperable valve flow path must be restored to OPERABLE status or the affected penetration flow path must be isolated. The method of isolation must include the use of at least one isolation barrier that cannot be adversely affected by a single active failure. Isolation barriers that Bases Insert D1 meet this criterion are a closed and de-activated automatic valve, a closed manual valve, and a blind flange. A check valve may not be used to isolate the affected penetration flow path. Required Action C.1 must be completed within the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion Time. The specified time period is reasonable considering the relative stability of the closed system (hence, reliability) to act as a penetration isolation boundary and the relative importance of maintaining SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-7 Rev. 3.0, 03-31-04 A2-20
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES ACTIONS (continued) containment integrity during MODES 1, 2, 3, and 4. In the event the affected penetration flow path is isolated in accordance with Required Action C.1, the affected penetration flow path must be verified to be isolated on a periodic basis.
This periodic verification is necessary to assure leak tightness of containment and that containment penetrations requiring isolation following an accident are isolated. The Completion Time of once per 31 days for verifying that each affected penetration flow path is isolated is appropriate because the valves are operated under administrative controls and the probability of their misalignment is low. Condition C is modified by a Note indicating that this Condition is only applicable to those penetration flow paths with only one containment isolation valve and a closed system. The closed system must meet the requirements of Ref. 3. This Note is necessary since this Condition is written to specifically address those penetration flow paths in a closed system.
Required Action C.2 is modified by two Notes. Note 1 applies to valves and blind flanges located in high radiation areas and allows these devices to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since access to these areas is typically restricted. Note 2 applies to isolation devices that are locked, sealed, or otherwise secured in position and allows these devices to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since the function of locking, sealing, or securing components is to ensure that these devices are not inadvertently repositioned.
Therefore, the probability of misalignment of these valves, once they have been verified to be in the proper position, is small.
[ D.1 d.
With the secondary containment BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDINGshield building bypass leakage rate (SR 34.6.3.118) [or purge valve leakage rate (SR 3.6.3.7)] not within limit, the assumptions of the safety analyses are not met. Therefore, the leakage must be restored to within limit. Restoration can be accomplished by isolating the penetration(s) that caused the limit to be exceeded by use of one closed and deactivated automatic valve, closed manual valve, or blind flange. When a penetration is isolated, the leakage rate for the isolated penetration is assumed to be the actual pathway leakage through the isolation device. If two isolation devices are used to isolate the penetration, the leakage rate is assumed to be the lesser actual pathway leakage of the two devices. The 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> Completion completion Time time for secondary containment BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDINGshield building bypass leakage is reasonable considering the time required to restore the leakage by isolating the penetration(s) and the relative importance of secondary containment bypass leakage to the overall containment function. [The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Completion time for purge valve leakage is acceptable considering the purge valves remain closed so that a gross breach of the containment does not exist.]
SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-8 Rev. 3.0, 03-31-04 A2-21
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES ACTIONS (continued)
REVIEWERS NOTE-----------------------------------------
[The bracketed options provided in ACTION D reflect options in plant design and options in adopting the associated leakage rate Surveillances.
The options (in both ACTION D and ACTION E) for purge valve leakage, are based primarily on the design - if leakage rates can be measured separately for each purge valve, ACTION E is intended to apply. This would be required to be able to implement Required Action E.3. Should the design allow only for leak testing both purge valves simultaneously, then the Completion Time for ACTION D should include the "24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for purge valve leakage" and ACTION E should be eliminated.))
[ E.1, E.2, and E.3 e.
In the event one or more containment purge valves in one or more penetration flow paths are not within the purge valve leakage limits, purge valve leakage must be restored to within limits, or the affected penetration flow path must be isolated. The method of isolation must be by the use of at least one isolation barrier that cannot be adversely affected by a single active failure. Isolation barriers that meet this criterion are a [closed and de-activated automatic valve, closed manual valve, or blind flange]. A purge valve with resilient seals utilized to satisfy this Required required Action E.1 must have been demonstrated to meet the leakage requirements of SR 34.6.3.76. The specified Completion completion Time time is reasonable, considering that one containment purge valve remains closed so that a gross breach of containment does not exist.
In accordance with this Required required Action E.2, this penetration flow path must be verified to be isolated on a periodic basis. The periodic verification is necessary to ensure that containment penetrations required to be isolated following an accident, which are no longer capable of being automatically isolated, will be in the isolation position should an event occur. This Required required Action does not require any testing or valve manipulation. Rather, it involves verification that those isolation devices outside containment capable of being mispositioned are in the correct position. For the isolation devices inside containment, the time period specified as "prior to entering MODE 4 from MODE 5 if not performed within the previous 92 days" is based on engineering judgment and is considered reasonable in view of the inaccessibility of the isolation devices and other administrative controls that will ensure that isolation device misalignment is an unlikely possibility.
SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-9 Rev. 3.0, 03-31-04 A2-22
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES ACTIONS (continued)
For the containment purge valve with resilient seal that is isolated in accordance with this Required required Action E.1e, SR 34.6.3.7 6 must be performed at least once every [92] days. This assures that degradation of the resilient seal is detected and confirms that the leakage rate of the containment purge valve does not increase during the time the penetration is isolated. The normal Frequency for SR 3.6.3.7, 184 days, is based on an NRC initiative, Generic Issue B-20 (Ref.
4). Since more reliance is placed on a single valve while in this Condition, it is prudent to perform the SR more often. Therefore, a Frequency of once per [92]
days was chosen and has been shown to be acceptable based on operating experience.
Required Action E.2e. is modified by two Notes. One of the Notes 1 applies to isolation devices located in high radiation areas and allows these devices to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since access to these areas is typically restricted. Note 2 The second Note applies to isolation devices that are locked, sealed, or otherwise secured in position and allows these devices to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since the function of locking, sealing, or securing components is to ensure that these devices are not inadvertently repositioned. ]
C.1 and C.2f.
With one or more penetration flow paths of a closed system design with one containment isolation valve inoperable, the inoperable valve flow path must be restored to OPERABLE status or the affected penetration flow path must be isolated. The closed system must meet the requirements of Ref. 3. The systems meeting the requirement of Ref. 3 include the steam generator blowdown valves, component cooling water system valves to and from the excess letdown heat exchanger, and auxiliary feedwater test valves. The associated penetrations include X-14A, X-14B, X-14C, X-14D, X-35, X 40A, X-40B, X-53, X-102 and X-104. The method of isolation must include the use of at least one isolation barrier that cannot be adversely affected by a single active failure. Isolation barriers that meet this criterion are a closed and de-activated automatic SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-10 Rev. 3.0, 03-31-04 A2-23
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES ACTIONS (continued) valve, a closed manual valve, and a blind flange. A check valve may not be used to isolate the affected penetration flow path. This Required required Action C.1 must be completed within the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion completion Timetime. The specified time period is reasonable considering the relative stability of the closed system (hence, reliability) to act as a penetration isolation boundary and the relative importance of maintaining containment integrity during MODES 1, 2, 3, and 4. In the event the affected penetration flow path is isolated in accordance with this Required required Action C.1, the affected penetration flow path must be verified to be isolated on a periodic basis.
This periodic verification is necessary to assure leak tightness of containment and that containment penetrations requiring isolation following an accident are isolated. A FrequencyThe Completion Time of once per 31 days for verifying that each affected penetration flow path is isolated is appropriate because the valves are operated under administrative controls and the probability of their misalignment is low.
Condition C is modified by a Note indicating that this Condition is only applicable to those penetration flow paths with only one containment isolation valve and a closed system. The closed system must meet the requirements of Ref. 3. This Note is necessary since this Condition is written to specifically address those penetration flow paths in a closed system.
Required Action C.2f. is modified by two Notes. One of the Notes 1 applies to valves and blind flanges located in high radiation areas and allows these devices to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since access to these areas is typically restricted. The second Note 2 applies to isolation devices that are locked, sealed, or otherwise secured in position and allows these devices to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since the function of locking, sealing, or securing components is to ensure that these devices are not inadvertently repositioned. Therefore, the probability of misalignment of these valves, once they have been verified to be in the proper position, is small.
SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-10 Rev. 3.0, 03-31-04 A2-24
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES ACTIONS (continued)
F.1 and F.2 g.
If the Required required Actions and associated Completion completion Times times are not met, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 within 36 the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.
SURVEILLANCE [ SR 34.6.3.1 REQUIREMENTS Each [42] inch containment purge valve is required to be verified sealed closed at 31 day intervals. This Surveillance is designed to ensure that a gross breach of containment is not caused by an inadvertent or spurious opening of a containment purge valve. Detailed analysis of the purge valves failed to conclusively demonstrate their ability to close during a LOCA in time to limit offsite doses. Therefore, these valves are required to be in the sealed closed position during MODES 1, 2, 3, and 4. A containment purge valve that is sealed closed must have motive power to the valve operator removed. This can be accomplished by de-energizing the source of electric power or by removing the air supply to the valve operator. In this application, the term "sealed" has no connotation of leak tightness. The Frequency is a result of an NRC initiative, Generic Issue B-24 (Ref. 5), related to containment purge valve use during plant operations. In the event purge valve leakage requires entry into Condition E, the Surveillance permits opening one purge valve in a penetration flow path to perform repairs. ]
[ SR 3.6.3.2 This SR ensures that the minipurge containment purge isolation valves are closed as required or, if open, open for an allowable reason. If a purge valve is open in violation of this SR, the valve is considered inoperable. If the inoperable valve is not otherwise known to have excessive leakage when closed, it is not considered to have leakage outside of limits. The SR is not required to be met when the containment purge isolation minipurge valves are open (only onset of supply and exhaust valves open) for the reasons stated. The valves may be opened for pressure control, ALARA or air quality considerations for personnel entry, or for Surveillances that require the valves to be open. The containment purge isolationminipurge valves are capable of closing in the environment following a LOCA. Therefore, these valves are allowed to be open for limited periods of time. The 31 day Frequency is consistent with other containment isolation valve requirements discussed in SR 34.6.3.35. ]
SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-11 Rev. 3.0, 03-31-04 A2-25
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 34.6.3.3 5 This SR requires verification that each containment isolation manual valve and blind flange located outside containment and not locked, sealed, or otherwise secured and required to be closed during accident conditions is closed. The SR helps to ensure that post accident leakage of radioactive fluids or gases outside of the containment boundary is within design limits. This SR does not require any testing or valve manipulation. Rather, it involves verification that those containment isolation valves outside containment and capable of being mispositioned are in the correct position. Since verification of valve position for containment isolation valves outside containment is relatively easy, the 31 day Frequency is based on engineering judgment and was chosen to provide added assurance of the correct positions. The SR specifies that containment isolation valves that are open under administrative controls are not required to meet the SR during the time the valves are open. This SR does not apply to valves that are locked, sealed, or otherwise secured in the closed position, since these were verified to be in the correct position upon locking, sealing, or securing.
The Note applies to valves and blind flanges located in high radiation areas and allows these devices to be verified closed by use of administrative means.
Allowing verification by administrative means is considered acceptable, since access to these areas is typically restricted during MODES 1, 2, 3, and 4 for ALARA reasons. Therefore, the probability of misalignment of these containment isolation valves, once they have been verified to be in the proper position, is small.
SR 35.6.3.4 This SR requires verification that each containment isolation manual valve and blind flange located inside containment and not locked, sealed, or otherwise secured and required to be closed during accident conditions is closed. The SR helps to ensure that post accident leakage of radioactive fluids or gases outside of the containment boundary is within design limits. For containment isolation valves inside containment, the Frequency of "prior to entering MODE 4 from MODE 5 if not performed within the previous 92 days" is appropriate since these containment isolation valves are operated under administrative controls and the probability of their misalignment is low. The SR specifies that containment isolation valves that are open under administrative controls are not required to meet the SR during the time they are open. This SR does not apply to valves that are locked, sealed, or otherwise secured in the closed position, since these were verified to be in the correct position upon locking, sealing, or securing.
This Note allows valves and blind flanges located in high radiation areas to be verified closed by use of administrative means. Allowing verification by administrative means is considered acceptable, since access to these areas is typically restricted during MODES 1, 2, 3, and 4, for ALARA reasons. Therefore, the probability of misalignment of these containment isolation valves, once they have been verified to be in their proper position, is small.
SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-12 Rev. 3.0, 03-31-04 A2-26
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 34.6.3.5 3 Verifying that the isolation time of each power operated or automatic power operated containment isolation valve is within limits is required to demonstrate OPERABILITY. The isolation time test ensures the valve will isolate in a time period less than or equal to that assumed in the safety analyses. [The isolation time and Frequency of this SR are in accordance with the Inservice Testing Program or 92 days.]Specification 4.0.5
[ SR 3.6.3.6 In subatmospheric containments, the check valves that serve a containment isolation function are weight or spring loaded to provide positive closure in the direction of flow. This ensures that these check valves will remain closed when the inside containment atmosphere returns to subatmospheric conditions following a DBA. SR 3.6.3.6 requires verification of the operation of the check valves that are testable during unit operation. The Frequency of 92 days is consistent with the Inservice Testing Program requirement for valve testing on a 92 day Frequency. ]
[ SR 34.6.3.7 6 For containment purge valves with resilient seals, additional leakage rate testing beyond the test requirements of 10 CFR 50, Appendix J, Option [A][B], is required to ensure OPERABILITY. Operating experience has demonstrated that this type of seal has the potential to degrade in a shorter time period than do other seal types. Based on this observation and the importance of maintaining this penetration leak tight (due to the direct path between containment and the environment), a Frequency of 184 days wasonce per 3 months is established.
as part of the NRC resolution of Generic Issue B-20, "Containment Leakage Due to Seal Deterioration" (Ref. 4).
Additionally, this SR must be performed within 92 days after opening the valve.
The 92 day Frequency was chosen recognizing that cycling the valve could introduce additional seal degradation (beyond that occurring to a valve that has not been opened). Thus, decreasing the interval (from 184 days) is a prudent measure after a valve has been opened. ]
SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-13 Rev. 3.0, 03-31-04 A2-27
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES SURVEILLANCE REQUIREMENTS (continued)
SR 34.6.3.8 2 Automatic containment isolation valves close on a containment isolation signal to prevent leakage of radioactive material from containment following a DBA. This SR ensures that each automatic containment isolation valve will actuate to its isolation position on a containment isolation signal. The containment isolation signals involved are Phase A, Phase B, Containment Ventilation Isolation, High Containment Pressure, and Safety Injection. This surveillance is not required for valves that are locked, sealed, or otherwise secured in the required position under administrative controls. The [18] month Frequency is based on the need to perform this Surveillance under the conditions that apply during a plant outage and the potential for an unplanned transient if the Surveillance were performed with the reactor at power. Operating experience has shown that these components usually pass this Surveillance when performed at the [18] month Frequency. Therefore, the Frequency was concluded to be acceptable from a reliability standpoint.
[ SR 3.6.3.9 In subatmospheric containments, the check valves that serve a containment isolation function are weight or spring loaded to provide positive closure in the direction of flow. This ensures that these check valves will remain closed when the inside containment atmosphere returns to subatmospheric conditions following a DBA. SR 3.6.3.9 verifies the operation of the check valves that are not testable during unit operation. The Frequency of 18 months is based on such factors as the inaccessibility of these valves, the fact that the unit must be shut down to perform the tests, and the successful results of the tests on an 18 month basis during past unit operation. ]
[ SR 34.6.3.10 7
REVIEWERS NOTE----------------------------------------
This SR is only required for those units with resilient seal purge valves allowed to be open during [MODE 1, 2, 3, or 4] and having blocking devices on the valves that are not permanently installed.
SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-14 Rev. 3.0, 03-31-04 A2-28
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES SURVEILLANCE REQUIREMENTS (continued)
Verifying that each [42] inch containment purge valve is blocked to restrict opening to [50]%50 degrees is required to ensure that the valves can close under DBA conditions within the times assumed in the analyses of References 1 and 2. If a LOCA occurs, the purge valves must close to maintain containment leakage within the values assumed in the accident analysis. At other times when purge valves are required to be capable of closing (e.g., during movement of
[recently] irradiated fuel assemblies), pressurization concerns are not present, thus the purge valves can be fully open. The 18 month Frequency is appropriate because the blocking devices are typically removed only during a refueling outage. ]
[ SR 34.6.3.11 8 This SR ensures that the combined leakage rate of all secondary containment BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDINGshield building bypass leakage paths is less than or equal to the specified leakage rate. This provides assurance that the assumptions in the safety analysis are met. The leakage rate of each bypass leakage path is assumed to be the maximum pathway leakage (leakage through the worse of the two isolation valves) unless the penetration is isolated by use of one closed and de-activated automatic valve, closed manual valve, or blind flange. In this case, the leakage rate of the isolated bypass leakage path is assumed to be the actual pathway leakage through the isolation device. If both isolation valves in the penetration are closed, the actual leakage rate is the lesser leakage rate of the two valves. The Frequency is required by the Containment Leakage Rate Testing Program. This SR simply imposes additional acceptance criteria.
Secondary containment BYPASS LEAKAGE PATHS TO THE AUXILIARY BUILDING[Bypass leakage is considered part of La.
REVIEWERS NOTE--------------------------------------
Unless specifically exempted.] ]
SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-14 Rev. 3.0, 03-31-04 A2-29
Standard Bases Insert Containment Isolation Valves (Atmospheric, Subatmospheric, Ice Condenser, and Dual)
B 3.6.3 BASES REFERENCES 1. UFSAR, Section [15.0], Accident Analysis..
- 2. UFSAR, Section [6.2.4], Containment Isolation Systems and Table 6.2.4-1, Containment Penetrations..
- 3. Standard Review Plan 6.2.4, Revision 2.
- 4. Generic Issue B-20, "Containment Leakage Due to Seal Deterioration."
- 5. Generic Issue B-24.
SEQUOYAH - UNIT # B 3/4 6-# Amendment No. #s WOG STS B 3.6.3-15 Rev. 3.0, 03-31-04 A2-30