NL-13-2479, Response to Request for Additional Information Regarding Technical Specification 3.7.14, Engineered Safety Features (ESF) Room Cooler and Safety Related Chiller System Condition a Completion Time Extension
| ML13340A381 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 12/05/2013 |
| From: | Pierce C Southern Co, Southern Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-13-2479 | |
| Download: ML13340A381 (9) | |
Text
Charles A. Pierce Southern Nuclear Regulatory Affairs Director Operating Company, Inc.
40 Inverness Center Parkway Post Office Box 1295 Binningham. AL 35242 Tel 205.992.7872 Fax 205.992.760 1 December 05, 2013 Docket Nos.: 50-424 NL-13-2479 50-425 U. S. Nuclear Regulatory Commission AnN: Document Control Desk Washington, D. C. 20555-0001 Vogtle Electric Generating Plant Response to Request for Additional Information Regarding Technical Specification 3.7.14, "Engineered Safety Features (ESF) Room Cooler and Safety Related Chiller System" Condition A Completion Time Extension Ladies and Gentlemen:
By letters dated September 26, 2012, and August 7, 2013, Southern Nuclear Operating Company (SNC) submitted a license amendment request (LAR) to revise the Completion Time for Technical Specification 3.7.14, "Engineered Safety Features (ESF) Room Cooler and Safety Related Chiller System." By letter dated November 7, 2013, the Nuclear Regulatory Commission (NRC) sent SNC a Request for Additional Information (RAI) letter. The Enclosure contains the SNC response to the NRC RAI letter.
This letter contains no NRC commitments. If you have any questions, please contact Ken McElroy at (205) 992-7369.
Mr. C. R. Pierce states he is Regulatory Affairs Director of Southern Nuclear Operating Company, is authorized to execute this oath on behalf of Southern Nuclear Operating Company and, to the best of his knowledge and belief, the facts set forth in this letter are true .
Respectfully submitted, C11 &:a C. R. Pierce Regulatory Affairs Director .. -. -'..
CRPIRMJllac swor sUb~=efore me this S ~
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to and day of ,2013.
~CbMLcd~0h Notary Public My commission expires: /0 13 f i
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U. S. Nuclear Regulatory Commission NL-13-2479 Page 2
Enclosure:
SNC Response to NRC RAls cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, President & CEO Mr. D. G. Bost, Executive Vice President & Chief Nuclear Officer Mr. T. E. Tynan, Vice President - Vogtle Mr. B. L. Ivey, Vice President - Regulatory Affairs Mr. D. R. Madison, Vice President - Fleet Operations RType: CVC7000 U. S. Nuclear Regulatory Commission Mr. V. M. McCree, Regional Administrator Mr. R. E. Martin, NRR Senior Project Manager - Vogtle Mr. L. M. Cain, Senior Resident Inspector - Vogtle State of Georgia Mr. J. H. Turner, Environmental Director Protection Division
VogtJe Electric Generating Plant Response to Request for Additional Information Regarding Technical Specification 3.7.14, "Engineered Safety Features (ESF) Room Cooler and Safety Related Chiller System" Condition A Completion Time Extension Enclosure SNC Response to NRC RAls
Enclosure to NL-13-2479 SNC Response to NRC RAls
Background
The table in Enclosure 6 (page E6-1) of the licensee's submittal dated September 26,2012, provides a listing of areas served and room numbers for the Unit 1 Train 1A ESF room chiller. The safety functions of the safety-related loads in the rooms listed on page E6-1 provide the required redundancy of the safety functions provided by the similar Unit 1 Train 1B ECW loads. When the inoperability of the 1A ECW chiller train is extended to 7 days, the safety-related loads in the rooms listed on page E6-1 are inoperable for 7 days and the required redundancy of the associated safety functions are lost.
Some safety-related functions have Technical Specifications (TSs) and corresponding Completion Times (CTs) that are greater than or equal to 7 days.
The temporary loss of redundancy is already satisfactorily taken into account by the TS. However, some loads have CTs less than 7 days {e.g. residual heat removal, containment spray, component cooling water pump rooms} and some loads may not have associated TSs.
Issue The staff needs to know the extent of safety-related systems and functions that are affected or become inoperable as a result of loss of an ESF chiller, including those that do not have TS.
RAI-1
For each room number listed on page E6-1 , please provide a listing by room number of all safety-related systems and functions [that are listed or described in TS and/or the Updated Final Safety Analysis Report] that have any safety-related component(s) in the room. Also, for each identified safety-related system and/or function, identify all associated TS.
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Enclosure to NL-13-2479 SNC Response to NRC RAls SNC Response to RAI-1 The requested table is provided below.
ESF Room Cooler Room Safety Related System and/or Function Affected Technical Number Specification 1-1531-N7-001-000 Main Control Control Room Emergency Filtration System LCO 3.7.10 Room 1-1532-A7-001-000 B84 MCC1CD1M Train C 125VDC Motor Control Center LCO 3.8.4 B76 1AB05 Train A 480V Switchgear LCO 3.8.9 1AB04 Train A 480V Switchgear MCC1ABC, Train A 480V Motor Control Center 1ABC B79 MCC1 ABE, Train A 480V Motor Control Center 1ABE LCO 3.8.9 B60 AC UNIT TRAIN "Au N/A B56 1CD1 B Battery LCO 3.8.4, 3.8.6 655 1CD1 Train C 125VDC Switchgear LCO 3.8.9 1CD1CA Train C Battery Charger LCO 3.8.4 1CD 1CB Train C Battery Charger 1CD11 Train C VDC Distribution Panel LCO 3.8.9 1CY1A Train C 120 VAC Vital Panel1CY1A LCO 3.8.9 1CD113 Vital AC Inverter LCO 3.8.7 1CD115 120V AC Inverter B54 1AD1 B Battery LCO 3.8.4, 3.8.6 B52 1AD1 Train A 125VDC Switchgear LCO 3.8.9 1AD11 125V Distribution Panel 1AD12 125V Distribution Panel 1AD1 M Train A 125VDC Motor Control Center LCO 3.4.11,3.7.5 1AD 1CA Train A BatteI}' Charger LCO 3.8.4 1AD1CB Train A Battery Charger 1AY1A Train A 120 VAC Vital Panel LCO 3.8.9 1AD111 Vital AC Inverter LCO 3.8.7 A48 Safety Sequencer Cabinet 1ACPSQ1 LCO 3.8.1 4160V Switchgear 1AA02 LCO 3.8.9 A75 Train A Shutdown Panel 1ACPSDA LCO 3.3.4 1-1539-A7 -001-000 A45 1ACPAR8 Auxiliary Relay Panel PAR8 N/A INCPAR5 Auxiliary Relay Panel PAR5 E-2
Enclosure to NL-13-2479 SNC Response to NRC RAls ESF Room Cooler Room Safety Related System and/or Function Affected Technical Number Specification IACPAR1 Auxiliary Relay Panel PAR1 1-1555-A7-001-000 1ABD105 480V SWGR 1AB15 LCO 3.8.9 1-1555-A7-003-000 1AB C109 MCC 1ABD Train A LCO 3.8.9 1-1555-A7 -005-000 1AB118 1ABB MCC Train A LCO 3.8.9 Inverter 1AD1111 LCO 3.8.7 1A Y2A 120V AC Vital Panel LCO 3.8.9 1-1555-A7 -007 -000 1ABD48 RHR Pump Train A LCO 3.5.2 1-1555-A7-009-000 1ABD76 Containment Spray Pump Discharge Train "A" LCO 3.6.6 1-1555-A7-011-000 1ABA05 Train A CCW Pump Room LCO 3.7.7 1-1555-A7-013-000 1ABC115 CVCS Centrifugal Charging Pump Train A LCO 3.5.2 1-1555-A7-015-000 1ABB15 Safety Injection Pump Train A LCO 3.5.2 1-1555-A7-017-000 1ABA53 Spent Fuel Pit Skim Pump N/A Spent Fuel Pit Pump Spent Fuel Heat Exchanger Train A 1-1561-E7-001-000 N/A Piping Penetration Area Filtration and Exhaust System 3.7.13 1-1539-A7-005-000 1CB325 480V MCC 1ABA LCO 3.8.9 !
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Enclosure to NL-13-2479 SNC Response to NRC RAls
RAI-2
Provide technical justification for extending the inoperability of the safety-related systems and/or functions identified in (a) above to 7 days. The technical justification may include, but not limited to, such factors as appropriate compensatory action and the availability of normal chilled water.
[Note: The licensee's statement in the September 26, 2012 submittal that the Conditions and Required Actions of the supported systems are not required to be entered as allowed by LCO 3.0.6" is not sufficient technical justification because the exception of TS 3.0.6 is justified when the actions that are required to ensure the unit is maintained in a safe condition are specified in the support system (ECW) LCO's Required Actions. This may not be the case when the support system CT is increased to 7 days.]
The staff recognizes that the licensee's response to this request for information will also apply to Unit 1 Train B and Unit 2 Trains A and B and will use it accordingly for the staff's safety evaluation.
SNC Response to RAI-2 The proposed compensatory actions for one chiller out of service were provided as Regulatory Commitments in letter NL-13-1648, dated August 7,2013. The table below lists each Regulatory Commitment provided in letter NL-13-1648, and a justification stating the benefit to each proposed compensatory action. Each of the Regulatory Commitments listed below are required within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of entering Condition A, and are specific to the affected unit.
Regulatory Commitments Basis The remaining train ESF Room This will maintain the safety function Cooler and Safety-Related Chiller to the redundant ESF Chiller and System will be operated as a Room Cooler Train.
Protected Train per procedure NMP OS-010.
The Unit 1 low voltage switchyards This action will maintain the reliability and the Unit 2 low voltage of both offsite AC sources of the switchyards will be maintained affected unit.
available (that is, no routine testing or maintenance activities will be performed).
High voltage switchyards will be This action will provide additional maintained available (that is, no oversight of activities and maintain routine testing or maintenance maximum reliability of the grid feed to activities will be performed) with the both offsite AC power sources of the exception of work activities which do affected unit.
not challenge both feeders from offsite power sources will be permitted and managed as a high Operational Risk Awareness job.
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Enclosure to NL-13-2479 SNC Response to NRC RAls The Unit 1 and Unit 2 Train A and This action will ma intain reliab ility of Train B Emergency Diesel both trains of onsite emergency AC Generators will be maintained power.
available (that is, no routine testing or maintenance activities will be performed).
The Normal Chilled Water System The Normal Chilled Water System will be maintained available (that is, provides cooling to the safety related no routine testing or maintenance components serviced by the affected activities will be performed). train of ESF Chiller and Room Coolers with the exception of CCW Pump Room, SI Pump room, CS Pump room, and Piping Penetration Area Filtration and Exhaust System (PPAFES). NSCW provides a backup to ESF Chilled Water for the PPAFES.
The opposite Unit's Essential Chilled This action will maintain Control Water System and the opposite Room habitability (environmental and Unit's CREFS will be maintained radiological) for both the affected and available to support control room unaffected units.
cooling (that is, no routine testing or maintenance activities will be performed).
Equipment room doors will be This is a compensatory measure to propped open for safety related maintain 120VAC and 125VDC 125VDC and 120VAC equipment capability in the event of a loss of all rooms on the affected train. AC power.
The compensatory actions listed will continue to demonstrate compliance with the single failure criteria and the requirements of General Design Criterion (GDC) 19 because:
- 1. The proposed action on the essential chiller only affects the chilled water system. It does not affect airflow into and out of the main control room .
Hence, the proposed change does not have any impact on the credited unfiltered in-leakage to the main control room.
- 2. The airflow to and from the control room will not be affected , and hence the contributing factors which affect the dose in the main control room will not be impacted.
- 3. The main control room HVAC system has two Unit 1 and two Unit 2 control room filtration/cooling units served by their respective train essential chilled water system. One of the four control room filtration/cooling units is sufficient for maintaining control room habitable conditions . Additionally , the control room has two non-safety related normal air conditioning units which are served by the normal chilled water system. Thus , if one train essential chilled water system is inoperable due to the unavailability of the chiller, the remaining trains (along with the normal air conditioning units) will be available to provide the E-5
Enclosure to NL-13-2479 SNC Response to NRC RAls necessary cooling requirements for maintaining the main control room habitable.
- 4. The redundant filtration/cooling units served by their respective train essential chilled water system and powered from the diesel generator will be available to provide the necessary cooling to the main control room to maintain it habitable during loss of offsite power.
For the supported systems declared inoperable as a result of entering LCO 3.7.14 Condition A, Specification 5.5.15, "Safety Function Determination Program (SFDP)," ensures loss of safety function is detected and appropriate actions are taken. Upon entry into LCO 3.0.6, an evaluation shall be made to determine if loss of safety function exists. Additionally, other limitations, remedial actions, or compensatory actions may be identified as a result of the support system inoperability and corresponding exception to entering supported system Conditions and Required Actions. The SFDP implements the requirements of LCO 3.0.6.
Cross train checks to identify a loss of safety function for those support systems that support multiple and redundant safety systems are required. The cross train check verifies that the supported systems of the redundant OPERABLE support system are OPERABLE, thereby ensuring safety function is retained . If this evaluation determines that a loss of safety function exists, the appropriate Conditions and Required Actions of the LCO in which the loss of safety function exists are required to be entered.
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