ML17117A320
| ML17117A320 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 12/12/2016 |
| From: | Cotton K Plant Licensing Branch II |
| To: | Geoffrey Miller Virginia Electric & Power Co (VEPCO) |
| References | |
| Download: ML17117A320 (6) | |
Text
From:
Cotton, Karen To:
"Gary D Miller"
Subject:
Surry RAI Date:
Monday, December 12, 2016 3:48:00 PM Attachments:
SURRY MF7746 RAIs.docx By letter dated May 18, 2016 (ML16146A540), Virginia Electric and Power Company submitted a License Amendment Request (LAR) to change TS 3.14, "Circulating and Service Water Systems," and delete expired License Conditions and TS requirements.
The amendment(s) would revise Surry Power Station (Surry) Units 1 and 2 Technical Specification (TS) 3.14, "Circulating and Service Water Systems," to extend the Allowed Outage Time (AOT) for only one operable Service Water (SW) flow path to the Charging Pump SW (CPSW) subsystem and to the Main Control Room/Emergency Switchgear Room (MCR/ESGR) Air Conditioning (AC) subsystem.
TS 3.14.A.5 and TS 3.14.A.7 require two SW flow paths to the CPSW subsystem and to the MCR/ESGR AC subsystem, respectively, to be operable. Currently, the TS 3.14.C AOT for only one operable CPSW or MCR/ESGR AC flow path is 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The proposed revision extends the AOT for only one operable CPSW or MCR/ESGR AC flow path from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 72 Hours.
The additional information requested in the attachment is necessary to complete the evaluation of this amendment request.
Please respond by January 13, 2017.
- Thanks, Karen Cotton Gross
1 DRAFT REQUEST FOR ADDITIONAL INFORMATION OFFICE OF NUCLEAR REACTOR REGULATION LICENSE AMENDMENT REQUEST REGARDING PROPOSED LICENSE AMENDMENT REQUEST EXTENSION OF TS 3.14 SERVICE WATER FLOW PATH ALLOWED OUTAGE TIME VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION 1 AND 2 DOCKET NOS. 50-280/281
RAI-1
TS 3.14.7.A.7 requires that two service water flow paths to the main control room and emergency switchgear room (MCR/ESGR) air conditioning subsystems be OPERABLE. With five chillers in the MCR/ESGR Air Conditioning System, TS 3.23.A requires three MCR/ESGR chillers be OPERABLE in certain required combinations (NRC staff computes 6 possible combinations that meet the requirements TS 3.23.A.1.b). Neither the TS basis nor the UFSAR define what constitutes a service water flow path to a MCR/ESGR air conditioning subsystem which meet the requirements of TS 3.14.7.A.7 nor do they explain what constitutes a MCR/ESGR air conditioning subsystem.
A) Define the bounds of a MCR/ESGR air conditioning subsystem specified in TS 3.14.A.7 and describe the relationship between the MCR/ESGR air conditioning subsystems and the MCR/ESGR chillers referenced in TS 3.23.A.
B) Define what constitutes a service water flow path to a MCR/ESGR air conditioning subsystem which meet the requirements of TS 3.14.7.A.7.
RAI-2
TS 3.14.A.7 requires that two service water flow paths to the main control room and emergency switchgear room (MCR/ESGR) air conditioning subsystems be OPERABLE. With five chillers in the MCR/ESGR Air Conditioning System, TS 3.23.A requires three MCR/ESGR chillers be OPERABLE in certain required combinations.
The guidelines of Regulatory Guide 1.177, An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications, state that when evaluating defense in depth for an AOT extension that system redundancy, independence, and diversity are maintained commensurate with the expected frequency and consequences of challenges to the system.
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A. For each allowed combination of 3 OPERABLE chillers (NRC staff computes 6 possible combinations which meet the requirements TS 3.23.A.1.b) and each applicable
2 MCR/ESGR subsystem identify all acceptable combinations of two service water flow paths that meet the requirements of TS 3.14.A.7.
B. While meeting the limiting conditions for operations of TSs 3.14.A.7 do any credited two service water flow paths to any MCR/ESGR subsystem, have any common components or piping. Explain. If so, provide further justification for extending the AOT from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, specifically addressing redundancy and independence of the two service water flow paths.
C. Can any single failure in the identified service water flow paths in B above cause more than one Chiller subsystem to be INOPERABLE? If so, provide further justification for extending the AOT from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, specifically addressing redundancy and independence.
RAI-3
TS 3.14.A.5 requires that two service water flow paths to the charging pump service water pump subsystem be OPERABLE. Neither the TS basis nor the UFSAR define what constitutes a service water flow path to the charging pump service water subsystem.
The guidelines of Regulatory Guide 1.177, An Approach for Plant-Specific, Risk-Informed Decisionmaking: Technical Specifications, state that when evaluating defense in depth for an AOT extension that system redundancy, independence, and diversity are maintained commensurate with the expected frequency and consequences of challenges to the system.
A. Identify all acceptable combinations of two service water flow paths that meet the requirements of TS 3.14.A.5.
B. While meeting the limiting conditions for operations of TSs 3.14.A.5, do any credited two service water flow paths to any charging pump service water subsystem, have any common components or piping. Explain. If so, provide further justification for extending the AOT from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, specifically addressing redundancy and independence of the two service water flow paths.
RAI-4
A. When in new proposed TS 3.14.C with only one OPERABLE service water flow path to the charging pump service water subsystem or main control and emergency switchgear room, identify the possible failures in the single service water flow paths that could make the flow path inoperable.
B. Describe compensatory actions that would restore OPERABILITY to these flow paths including the time to restore OPERABILITY and the resulting impact upon plant safety.
C. Describe any possible lineups including cross connecting that would reduce the risk of having only one OPERABLE service water flow path to the charging pump service water subsystem.
3 10 CFR 50.36(c)(2)i states:
Limiting conditions for operation are the lowest functional capability or performance levels of equipment required for safe operation of the facility. When a limiting condition for operation of a nuclear reactor is not met, the licensee shall shut down the reactor or follow any remedial action permitted by the technical specifications until the condition can be met.
10 CFR 50.90 states:
Whenever a holder of a license, including a construction permit and operating license under this part, and an early site permit, combined license, and manufacturing license under part 52 of this chapter, desires to amend the license or permit, application for an amendment must be filed with the Commission, as specified in §§ 50.4 or 52.3 of this chapter, as applicable, fully describing the changes desired, and following as far as applicable, the form prescribed for original applications.
Surry TS 3.14.A.5, 3.14.A.6, and 3.14.A.7 require two OPERABLE service water flow paths to the charging pump service water subsystems, the recirculation spray subsystems and the main control room and emergency switchgear room air conditioning subsystems, respectively.
The current TS requirements contain remedial actions which allow 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of plant operation with only one OPERABLE flow path to the charging pump service water subsystems, recirculation spray subsystems and the main control room and emergency switchgear room and emergency switchgear rooms air conditioning condensers.
Current TS 3.14.C states:
The requirements of Specifications 3.14.A.5, 3.14.A.6, and 3.14.A.7 may be modified to allow unit operation with only one OPERABLE flow path to the charging pump service water subsystem, the recirculation spray subsystems, and to the main control and emergency switchgear rooms air conditioning condensers. If the affected systems are not restored to the requirements of Specifications 3. 14.A.5, 3.14.A.6, and 3.14.A.7 within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the reactor shall be placed in HOT SHUTDOWN. If the requirements of Specifications 3. 14.A. 5, 3.14.A. 6, and 3. 14.A. 7 are not met within an additional 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, the reactor shall be placed in COLD SHUTDOWN.
On page 3 of Attachment 1, the proposed change to TS 3.14.C states:
The requirements of Specifications 3.14.A.5 and 3.14.A.7 may be modified to allow unit operation with only one OPERABLE flow path to the charging pump service water subsystem and to the main control and emergency switchgear rooms air conditioning condensers. If the affected systems are not restored to the requirements of Specifications 3.14.A.5 and 3.14.A.7 within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, the reactor shall be placed in HOT SHUTDOWN within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. If the requirements of Specifications 3.14.A.5 and 3.14.A.7 are not satisfied as allowed by this Specification, the reactor shall be placed in COLD SHUTDOWN within the next
4 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
The proposed new TS 3.14.D states:
The requirements of Specification 3.14.A.6 may be modified to allow unit operation with only one OPERABLE flow path to the recirculation spray subsystems. If the affected system is not restored to the requirements of Specification 3. 14.A. 6 within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the reactor shall be placed in HOT SHUTDOWN within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. If the requirements of Specification 3. 14.A. 6 are not met within an additional 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, the reactor shall be placed in COLD SHUTDOWN within the next 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
The Service Water System supports the operability of the Main Control Room and Emergency Switchgear Room Air Conditioning System by providing a heat sink for the Main Control Room and Emergency Switchgear Room chillers. Page 7 of attachment 1 of the LAR provides a limited discussion comparing the TS 3.23A.1c allowance of 7 days of continued operation with an inoperable chiller to the proposed allowance of continued operation with only one OPERABLE flow path to the main control and emergency switchgear rooms air conditioning condensers. The discussion does not compare the short, 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, allowed continued operational time with two inoperable chillers provided by TS 3.23A.1d with the proposed allowance of continued operation with only one OPERABLE flow path to the main control and emergency switchgear rooms air conditioning condensers.
RAI-5
The proposed change appears to increase the number of hours the plant would be allowed to operate with only one operable CPSW or MCR/ESGR AC flow path from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 78 hours9.027778e-4 days <br />0.0217 hours <br />1.289683e-4 weeks <br />2.9679e-5 months <br />.
The justification for the proposed change and the description of the proposed change only discuss a change from 24 to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. Please either provide a supplementary justification for the extra six hours of allowed operation not discussed in attachment 1 of the LAR or revise the proposed change to TS 3.14.C.
RAI-6
Likewise, the proposed addition of new TS 3.14.D appears to increase the number of hours the plant would be allowed to operate with only one operable recirculation spray subsystems flow path from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. The justification for the proposed change and the description of the proposed change does not discuss the extra six hours of allowed operation. Please either provide a supplementary justification for the extra six hours of allowed operation not discussed in attachment 1 of the LAR or revise the proposed addition of new TS 3.14.D
RAI-7
Please provide a discussion which compares the short, 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, allowed continued operational time with two inoperable chillers provided by TS 3.23A.1d with the proposed allowance of
5 continued operation with only one OPERABLE flow path to the main control and emergency switchgear rooms air conditioning condensers. The discussion should describe why the proposed allowance is justified, despite the apparent discrepancy with the requirements of TS 3.23A.1d. That is, please provide detail as to how the requirements of TS 3.23 will continue to be met if one service water flow path is inoperable.