ML053120390

Revised Station Blackout Evaluation

ML053120390
Person / Time
Site:	Palo Verde
Issue date:	10/28/2005
From:	Mauldin D Arizona Public Service Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
102-05370-CDM/TNW/RAB
Download: ML053120390 (48)

Text

10 CFR 50.63 David Mauldin Vice President Mail Station 7605 Palo Verde Nuclear Nuclear Engineering Tel: 623-393-5553 PO Box 52034 Generating Station and Support Fax: 623-393-6077 Phoenix, Arizona 85072-2034 102-05370-CDM/TNW/RAB October 28, 2005 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Units 1, 2 and 3 Docket Nos. 50-5281529/530 Revised Station Blackout (SBO) Evaluation The station blackout (SBO) coping requirements of 10 CFR 50.63, Loss of All Alternating Current Power, are currently met for the Palo Verde Nuclear Generating Station (PVNGS) by having the capability to cope with an SBO for up to four hours.

Arizona Public Service Company (APS) has agreed to revise the PVNGS SBO coping duration from four hours to 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> to gain margin relative to nuclear safety. By letter No. 102-05313, dated July 19, 2005, Arizona Public Service Company (APS) committed to complete its evaluations and analyses for coping with an SBO for 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />, and to submit them to the NRC for review and approval by October 31, 2005 along with a schedule for implementation of the revised coping strategy. The results of the evaluation are provided in the Enclosure. By letter No. 102-05363, dated October 21, 2005, APS proposed a license condition to implement the changes needed to revise from a four hour station blackout coping duration to a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping duration within six months following NRC approval of the proposed coping changes.

The revised SBO evaluation and analysis were performed to provide the information required by 10 CFR 50.63, and were performed using the guidance provided in Regulatory Guide 1.155, "Station Blackout" and in NUMARC 87-00, "Guidelines and Technical Bases for NUMARC Initiatives Addressing Station Blackout at Light Water Reactors." The evaluation has determined that PVNGS can cope with a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> SBO.

In order to implement 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> SBO coping, changes to procedures will be required and training will need to be conducted on those procedure changes. Also, the control air system will be supplemented to support atmospheric dump valve operation for the longer coping period.

Abt A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Comanche Peak

• Diablo Canyon

• Palo Verde

• South Texas Project

• Wolf Creek C

ATTN; Document Control Desk U. S. Nuclear Regulatory Commission Revised Station Blackout (SBO) Evaluation Page 2 If changes are required to the Security or Emergency Preparedness programs, these changes will made in accordance with 10 CFR 50.54 (p) and 10 CFR 50.54 (q),

respectively.

No commitments are being made to the NRC by this letter.

Should you have any questions, please call Mr. Thomas N. Weber at (623) 393-5764.

Sincerely, CDM/TNW/RAB/ca

Enclosure:

Palo Verde Nuclear Generating Station, Units 1, 2 and 3, Station Blackout Evaluation cc: B. S. Mallet NRC Region IV M. B. Fields NRC Project Manager G. G. Warnick NRC Senior Resident Inspector for PVNGS

Enclosure Palo Verde Nuclear Generating Station Units 1, 2 and 3 Station Blackout Evaluation

Enclosure INTRODUCTION........................................................................................................1 A. COMPARISON OF STATION BLACKOUT DURATION ....................................... 2 B. COPING STUDY ............................................................. 3

C. PROCEDURE

S ............................................................. 37 D. QUALITY ASSURANCE AND SPECIFICATION FOR NONSAFETY RELATED STATION BLACKOUT EQUIPMENT ............................................................ 38 E. IMPLEMENTATION ............................................................ 43 REFERENCES ............................................................ 43

Enclosure PALO VERDE NUCLEAR GENERATING STATION UNITS 1,2, and 3 STATION BLACKOUT EVALUATION INTRODUCTION 10 CFR Part 50.63 requires that each light water-cooled nuclear power plant be able to withstand and recover from a station blackout (SBO) of a specified duration.

This evaluation revises the Palo Verde SBO coping strategy from a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> coping plant to a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping plant. In order to gain margin relative to nuclear safety, a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> SBO coping will be implemented.

The original Palo Verde study for SBO (Reference 1), for a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> coping strategy, was reviewed and accepted by the NRC in Reference 2. This study assumed that the unit would achieve and maintain Hot Standby using the steam generator (SG) atmospheric dump valves (ADVs) for heat removal, and that a charging pump would be used for reactor coolant system (RCS) inventory control.

The proposed 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping strategy ensures the alternate AC (AAC) is started and loading during the first hour. At the end of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, the operators would start a cooldown to shutdown (SDC) entry conditions. The ADVs will be used for heat removal, the pressurizer vent will be used for RCS pressure control, and RCS inventory will be controlled using a high pressure safety injection (HPSI) pump.

This submittal requests NRC approval for methodologies different from those described in NUMARC 87-00 (Reference 3). The following analyses were performed using methodologies different from those recommended in NUMARC 87-00:

• The CENTS computer code is used to simulate plant performance.

• The computer program COPATTA is used to calculate containment temperature and pressure.

Palo Verde will implement the modifications and procedures proposed in this submittal within 6 months of approval by the NRC.

Page 1 of 44

Enclosure A. COMPARISON OF STATION BLACKOUT DURATION Table 1 provides a comparison of the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping strategies.

Table 1, Comparison of 4 Hour and 16 Hour Coping Strategies 4 Hour Coping 16 Hour Coping Reflux boiling, hot standby for 4 Natural circulation, hot standby for 4 Unit Condition hours. bhours followed by a cooldown to SDC nhours. conditions.

Seconda Heat Use steam driven auxiliary Use steam driven AFW pump and econary emovaADVs feedwater (AFW) pump to maintain and RCS conditions ADVs to maintain After cooldown RCS enter conditions.

SDC.

Natural circulation through the SGs.

Primary Heat Reflux bolin After SDC entry, essential spray pond Removal 9n system (SPS) and essential cooling water system (EWS)

Primary Inventory Charging pump HPSI pump (1)

Control Primary Pressure Pressurizer sprays Pressurizer vent Control RCS Leakage 120 gpm111 gpm ADV accumulators, the control air Air Supply ADV accumulators system will be supplemented MC Source Power 3400 kW, 3400 kW, Note (1): HPSI is used for bounding RCS leakage. If the event results in smaller RCS leakage, the charging pump(s) can be used.

The decay heat used for the 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> analyses discussed herein is based on the ANSI/ANS-5.1 1979 decay heat curve, plus a 2 sigma uncertainty. The time dependent decay heat is developed using the following parameters:

• Fuel enrichment = 5%

• Fuel bumup up to 70,000 MWD/MTU

• Power level = 3990 MWt The resultant decay heat curve is conservative, bounding, and consistent with industry practices for this type of evaluation.

Page 2 of 44

Enclosure B. COPING STUDY The ability of PVNGS to cope with an SBO was assessed, with the following results.

1. Condensate Inventory for Decay Heat Removal The original evaluation (Reference 1), completed per NUMARC 87-00 guidelines, required approximately 156,000 gallons of condensate. The revised evaluation, using the CENTS Code, requires approximately 242,000 gallons to make-up for decay heat, sensible heat, and the heat from SG inventory.

Technical Specification (TS) 3.7.6 requires Ž 29.5 ft or a usable volume of 2 300,000 gallons in the condensate storage tank (CST).

No plant or procedure changes are required to implement a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping strategy.

2. Assessing the Class 1E Battery Capacity There is no effect on the Class 1E batteries caused by the increased coping period. As in the original study, the battery chargers are loaded onto the gas turbine generators (GTGs) at 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. The batteries have more than adequate capacity to supply the required loads during the first hour of an SBO event.

No plant or procedure changes are required to implement a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping strategy.

3. AAC Power Source Two GTGs designated as AAC power sources are available at 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> of the onset of the SBO event. Each GTG has sufficient capacity and capability to operate those systems necessary for coping with an SBO for the required duration of 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> to bring the plant to and maintain the plant in a safe shutdown condition.

The AAC evaluation presented in Reference 1 remains applicable for a coping duration of 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />.

The alternate AC (AAC) source has the capacity and capability to power the equipment necessary to cope with an SBO, for the required coping duration of 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />. The summary of loads required to cope with a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> SBO is provided in Table 2. The continous load on a single GTG is 3364.3 Kw.

Before delivery to Palo Verde, each GTG was factory tested and demonstrated a 5.8% capacity margin above 3400 kWe. The GTGs are maintained and tested to ensure their capability to supply the load required to cope with an SBO for 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />.

The fuel tanks associated with the GTGs are maintained with sufficient fuel to support operation of the two GTGs for 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />.

Procedure changes for operation and loading the GTG are required to support a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping strategy. These changes are described in Sections C and E.

Page 3 of 44

Enclosure Table 2, Loads - 16 Hour Station Blackout Coping (1 Page 1 of 3 Location Load Load Units Bhp kW Description 1ENKNH21 96.00 kVA 81.6 NON CLASS IE BATTERY CHARGER 1ENNAV13 23.00 kVA 19.6 SINGLE PHASE VOLTAGE REGULATING TRANSFORMER 1EPHAD31 14.00 kVA 12.6 120/240 AC DISTRIBUTION PANEL 1EPHAD33 5.00 kVA 4.5 120/240 AC DISTRIBUTION PANEL 1EPHAD37 5.00 kVA 4.5 120/240 AC DISTRIBUTION PANEL 1EPKAH11 80.00 kVA 68.0 LASS IE BATTERY CHARGER (A) 1EPKCH13 58.00 kVA 49.3 LASS IE BATTERY CHARGER (C) 1EQBAV01 25.00 kVA 21.3 INGLE PHASE VOLTAGE REGULATING TRANSFORMER 1EQBND91 90.00 kW 90.0 AIN ESSENTIAL LIGHTING PANEL 1EQFND23 25.00 kVA 21.3 OMM EQ UPS POWER SUPPLY DISTRIBUTION PANEL 1EQFNNO2 30.00 kVA 28.5 OMM UPS PANEL 1EQFNX01 12.00 kVA 10.8 MICROWAVE ROOM DISTRIBUTION PANEL TRANSFORMER 1EQMAV31 6.00 kVA 5.4 SINGLE PHASE REGULATING TRANSFORMER 1ERCNJ01A 150.00 kW 150.0 PRESSURIZER BACKUP HEATERS J-BOX (CLASS 1E FED)

IESQND01 14.90 kVA 13.4 DIATION MONITOR DISTRIBUTION PANEL 1JECAE01 5.03 kVA 4.3 SSENTIAL CHILLER AUXILIARY POWER PANEL 1JSQARU29 1.50 HP 1.5 1.9 DIATION MONITOR BLOWER MOTOR FOR CONTROL ROOM 1MDGAM01 40.00 kW 40.0 IESEL GENERATOR (DG) JACKET WATER HEATER 1MDGAM02 19.00 kW 19.0 IESEL GENERATOR 'A' LUBE OIL WARM-UP HEATER 1MDGAM03 4.00 kW 4.0 IESEL GENERATOR 'A' CRANKCASE HEATER 1MDGAP01 5.00 HP 5.0 4.6 IESEL GENERATOR WATER JACKET HEATER PUMP Page 4 of 44

Enclosure Table 2, Loads - 16 Hour Station Blackout Coping (1)

Page 2 of 3 Location Load Load Units Bhp kW Description 1MDGAP04 20.00 HP 20.0 17.5 DIESEL GENERATOR PRE-LUBE PUMP 1MECAE01 503.00 HP 503.0 402.6 ESSENTIAL CHILLER IMECAP01 20.00 HP 14.4 11.8 ESSENTIAL CHILLED WATER PUMP 1MEWAP01 800.00 HP 698.6 550.3 ESSENTIAL COOLING WATER SYSTEM PUMP 1MHAAZO1 5.00 HP 3.2 3.0 AUX BLDG HPSI PUMP ROOM ESSENTIAL AIR CONTROL UNIT (ACU) 1MHAAZO2 3.00 HP 1.2 1.2 AUXILIARY BLDG LPSI PUMP ROOM ESSENTIAL ACU 1MHAAZO3 3.00 HP 2.0 1.9 AUX BUILDING CONTAINMENT SPRAY PUMP ROOM ESSENTIAL ACU 1MHAAZO4 5.00 HP 3.2 3.0 AFW PUMP ROOM ESSENTIAL ACU 1MHAAZO5 3.00 HP 2.0 1.9 AUX BUILDING ESSENTIAL COOLING WATER PUMP RM ESSENTIAL ACU 1MHAAZO6 3.00 HP 1.8 1.7 UXILIARY BUILDING ELECTRIC PENETRATION RM ESSENTIAL ACU 1MHDAA01 20.00 HP 14.8 12.4 DG BLDG CONTROL RM ESSENTIAL AIR HANDLING UNIT 1MHJAF04 125.00 HP 109.7 87.1 CONTROL ROOM ESSENTIAL AIR FILTER 1MHJAJ01A 1.00 HP 0.4 0.5 CONTROL BLDG BATTERY ROOM A ESSENTIAL EXHAUST FAN 1MHJAJ01B 1.00 HP 0.4 0.5 CONTROL BLDG BATTERY ROOM C ESSENTIAL EXHAUST FAN 1MHJAZO3 7.50 HP 6.0 5.4 CONTROL BLDG ESF SWITCHGEAR ESSENTIAL AIR HANDLING UNIT I MHJAZO4 7.50 HP 6.0 5.1 CONTROL BLDG ESF EQUIPMENT ESSENTIAL AIR HANDLING UNIT 1MHJNJO6 13.00 kVA 11.1 MICROWAVE ROOM AIR CONDITIONER 1MHSAJ01 10.00 HP 9.5 8.0 PRAY POND PUMP HOUSE EXHAUST FAN 1MHTNJ02A 1.50 HP 0.7 0.9 TURBINE BUILDING BATTERY ROOM EXHAUST FAN 1MPCAP01 100.00 HP 64.7 52.3 FUEL POOL COOLING PUMP IMSIAP02 1000.00 HP 997.7 785.9 HIGH PRESSURE SAFETY INJECTION PUMP (2)

Page 5 of 44

Enclosure Table 2, Loads - 16 Hour Station Blackout Coping (1 Page 3 of 3 Location Load Load Units Bhp kW Description 1MSPAP01 600.00 HP 601.3 476.7 ESSENTIAL SPRAY POND PUMP kENHNM73 77.50 kVA 65.9 GAS TURBINE GENERATOR AUXILIARIES J1-SWYD 200.00 kVA 170.0 VNGS SWITCHYARD LOADS MISC. LOAD 33 TRANSFORMER & LINE LOSSES TOTAL LOAD 3364.3 TOTAL CONTINUOUS LOAD ON A SINGLE GAS TURBINE GENERATOR (2) 1MCHAP01 100.00 HP 74.9 60.5 CHARGING PUMP (2) 1MCHEP01 100.00 HP 74.9 60.5 HARGING PUMP (2)

Notes (1): This Table provides specific data for Palo Verde Unit 1 and is representative of Palo Verde Units 1, 2, and 3.

The Table does not include intermittent loads such as motor operated valves that have no significant effect on GTG capacity.

(2): The charging pumps are run separately from the HPSI pump and not included in the 3364.3 kW load. With 2 charging pumps in operation the total GTG load is 2699.4 kW.

Page 6 of 44

Enclosure

4. Compressed Air The SG ADVs are the primary means of heat removal during an SBO. The ADVs are air operated valves with a backup nitrogen accumulator. For the 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping time, the backup accumulators would be marginal, requiring a supplementary compressed air system. The control air system will be supplemented to support ADV operation for a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> SBO.

A plant modification and procedure changes to provide a supplement to the control air system for the ADVs is required to support a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping strategy.

These changes are described in Sections C and E.

5. Effects of Loss of Ventilation

a. Inside Containment No design basis accidents (DBAs)'(i.e., loss of coolant accidents (LOCAs) or steam line breaks) or beyond DBAs (i.e., resulting in core damage) are assumed coincident with an SBO. Therefore, environmental concerns inside containment are limited to (1) loss of cooling water, and (2) loss of ventilation systems and (3) limited reactor coolant pump (RCP) seal leakage. SBO results in a slow heatup of containment due to loss of ventilation and RCP leakage and temperatures in a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> SBO are bounded by'thermal profiles considered for DBA - LOCA event.

An analysis has been performed to determine the 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> SBO temperature and pressure response of the containment atmosphere. Since the duration of the event exceeded the bases provided within NUMARC 87-00. The NUMARC 87-00 do not include the effects of possible RCS leakage. In lieu of the NUMARC 87-00 method, the computer program COPATTA (quality related software, Bechtel Corp) is used. The COPATTA computer code is the program used to perform Palo Verde's LOCA and main steam line break (MSLB) containment temperature and pressure analyses as presented in the UFSAR.

The design basis accident model is adjusted for SBO. The containment temperature and pressure response to a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> SBO has been calculated considering both the sensible and the latent heat addition to the containment.

The sensible heat is from the component hot surfaces including the primary and secondary system. The latent heat addition is from the RCS and RCP seal leakage of 111 gpm (25 gpm/RCP plus 11 gpm TS 3.4.14 leakage) in addition to RCS discharge from pressurizer vent valve. The analysis credits a conservative heat transfer for passive heat sinks in the containment, however no active cooling by sprays or air coolers is assumed. Selection of the heat transfer coefficient is based on leakage from RCP seals to containment environment that will produce a saturated atmosphere, and the dominant means of heat transfer will be by condensation. Consistent with previous analyses of the long-term containment responses, the Uchida condensing heat transfer correlation is used.

Use of the Uchida condensing heat transfer is conservative, as the turbulence induced by the RCS discharge into the containment is not considered. To Page 7 of 44

Enclosure l.e produce a conservative bounding model for the containment environment the following additional conservatism has been built into the methodology:

i. RCP leakage rate and enthalpy has been assumed constant for duration of 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />.

ii. Sensible heat from the RCS and secondary system has been selected to reflect conditions at 100% power operation, and it is assumed constant for the duration of event.

iii. Minimal quantities of containment heat sinks are assumed available for the duration of the event. All heat sink areas are conservatively reduced to account for the possibility that not all the containment heat sinks would directly see the full effects of the RCP seal discharge and the sensible heat load. Specifically, the heat sink area outside the SG compartment D-rings below the operating deck may not be as effective. Based on the physical drawings, by inspection this area accounts for about one third of the total height of the containment. Therefore, all heat sink areas are reduced by 30 percent. This is a very conservative assumption because (1) the areas of all heat sink categories are reduced and (2)the heat sink area outside the SG compartment D-rings below the operating deck would be expected to have some effectiveness. Mixing will result from steam rising to the top of the containment, and natural drafts will be enhanced by steam condensing throughout the containment.

iv. To bound all conditions, initial event conditions were selected to be at TS limits used are:

• Initial containment temperature 120 OF TS 3.6.5 (the indicated limit of 117 OF ensures that the actual limit of 120 IF will not be exceeded

• Initial containment pressure 2.5 psig TS 3.6.4 Based on the conservative assumptions stated above, bounding 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> containment temperature and pressure profiles during SBO with RCP leakage are shown in Figure 1 and Figure 2. The peak temperature and pressure remain well below the LOCA and MSLB DBA for the duration of the event. Therefore, equipment within the containment will perform their intended function for the duration of the event. The current equipment qualification (EQ, 10 CFR 50.49) bounds the SBO environment.

No plant or procedure changes are required to implement a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping strategy.

Page 8 of 44

Enclosure Figure 1 Containment Pressure Response during SBO 40 35-30-c:

T 25-A e

(0 W

V) 20

_1 in:=i=

5 - 4- 4 + 4 0 - + t 4 1*

0.0 10000.0 20000.0 30000.0 40000.0 50000.0 60000.0 Time (sec)

Page 9 of 44

Enclosure Figure 2 Containment Temperature Response during SBO 250 200

, 150

'id E

C I 100 II I I I 50 *1- + .4. .4. 4 0 + + + +

0.0 10000.0 20000.0 30000.0 40000.0 50000.0 60000.0 Time (sec)

Page 10 of 44

Enclosure

b. Outside Containment The change in SBO duration to 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> has no impact on the previous conclusion supporting the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> SBO. The extended coping duration does not add any new dominant areas of concern for consideration since for all rooms with essential equipment, the essential air handling unit (AHU) will be available after AAC is available (at 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />). Table 3 provides a list of rooms reviewed or reanalyzed. Small deviations from NUMARC 87-00 were necessitated due to plant specific geometries and heat sources. Additionally a heat sink (floor) was included where the rooms were located in plant areas with no contact to soil.

Similar to the original coping study (Reference 1), additional heat source steam leakage was added to the AFW steam driven pump room evaluation to assure a bounding analysis.

Required SBO support equipment in the rooms was evaluated to ensure a basis existed to provide an adequate assurance of operation in accordance with NUMARC 87-00.

No plant or procedure changes are required to implement a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping strategy.

Page 11 of 44

Enclosure Table 3, Assessment of Equipment Operability Outside the Containment During SBO In all cases essential heating ventilation and air conditioning (HVAC) will be available after AAC Is available (at 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />)

Room Classification Room Methodology NUMARC 87-00, Remarks 2.7.1(2)

Control Room NUMARC 87-00, Condition 1 Heat sinks considered, in addition to NUMARC 87-00 heat sinks, the floor slab was added.

2.7.1(2) and 7.2.4, Equipment within room was reviewed for operability and it is concluded all equipment are Appendix F and H l operablelfunctional for duration of event.

DC NUMARC 87-00, Condition 2 Heat sinks considered, in addition to NUMARC 87-00 heat sinks, the floor slab was added.

Equipment 2.7.1(2) and 7.2.4, Equipment within room was reviewed for operability and it is concluded all equipment are Rooms Appendix F and H operable/functional for duration of event.

Emergency NUMARC 87-00, Condition 1 Heat sinks considered, in addition to NUMARC 87-00 heat sinks, the floor slab was added.

Switchgear 2.7.1(2) and 7.2.4, Equipment within room was reviewed for operability and it is concluded all equipment are Rooms Appendix F and H operablelfunctional for duration of event.

Battery No specific analysis Condition 1 These rooms have no heat load during SBO event.

Rooms Equipment within room was reviewed for operability and it is concluded all equipment are operablelfunctional for duration of event.

Charging NUMARC 87-00, Condition 2 Heat sinks considered, in addition to NUMARC 87-00 heat sinks, the floor slab was added.

Pump Rooms 2.7.1(2) and 7.2.4, Equipment within room was reviewed for operability and it is concluded all equipment are Appendix F and H _operable/functional for duration of event.

ESF Pump No new analysis Condition 1 Components can not be started until availability of AAC. SBO is no different than any design Rooms required basis event (DBE). The equipment is operable under current DBE 10CFR50.49 program.

Therefore equipment would remain operable during an SBO.

AFW - Steam NUMARC 87-00, Condition 3 Using methodology presented in appendix F of the NUMARC 87-00. The equipment Driven Pump 2.7.1(2) and 7.2.4, continued to perform its intended function.

Room Appendix F and H Page 12 of 44

Enclosure

6. Containment Isolation A review of plant containment isolation valves was performed to ensure that containment integrity is provided during the SBO event. NUMARC 87-00, Section 7.2.5 defines "containment integrity" as the capability for valve position indication and closure of containment isolation valves independent of the preferred class 1E power supplies. The containment isolation valves requiring this capability are valves that may be in the open position at the onset of an SBO.

Acceptable means of position indication includes local mechanical indication, DC-powered indication and AAC-powered indication. All station containment isolation valves were identified by performing a review of the plant design bases.

Table 4 includes a list of containment isolation valves, detailed information about each of the valves and the reasoning for acceptance to satisfy NUMARC 87-00 requirements.

Based on this review, it is concluded that under SBO conditions, containment integrity is accomplished No plant or procedure changes are required to implement a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping strategy.

Page 13 of 44

Enclosure Table 4, Containment Isolation Valves

_ _ _____ Page 1 of 8 Valve Primary Secondary Vave position ESF Power Source Valve Valve Applicable steps of NUMARC 87-00, section 7.2.5 & other System Valve Numbers Opertor Actuation Actuation Nor a Post- Failure Actuation (rain) Size On. references Oprtr Mode Mode NomlAccident FlueSignal I Tan ie(n) yerfrne AF AFB-UV035 Motor R R C 0 FAI AFAS-2 PH (B) 6 Gate Primary and secondary and act as containment boundary. Lack of AFE-V080 None A A C 0 NA None NA 6 Check solation would not result In breach of containment. Normal leakages AFBPSVO107 None A A C C NA None NA Y/X1 Relief m primary to secondary would be limited. Water level In FAPSVO109 None A A C C NA None NA /jX1 Relief secondary would reduce any release associatedwith normal leakage FA-UV037 Motor R R C 0 FAI AFAS-2 PK (A) 6 Gate though these pathways. Special application of closed- loop system FE-V079 None A A C 0 NA *None NA 6 Check Example, Refer to step 1.4.

FC-UV036 Motor R R C 0 FAI AFAS-1 PK (C) 6 Gate FBPSV0106 None A A C C NA None NA Y/X1 Relief FAPSV0108 None A A C C NA None NA %X1 Relief

_AFB-UV034 Motor R R C 0 FAI AFAS-1 PH (B) 6 Gate CH CHA-UV506 Pneumatic A R, M 0 C C CSAS IA 1 Globe Exempt; refer to step 1(5)

CVCS I PK(A)

CHB-UV505 Pneumatic A R 0 C C CSAS IA 1 Globe PK(B)

CHA-UV560 Pneumatic A R OorC C C CIAS IA 3 Globe OV valve would fail close.

._ PK(A)

CHB-UV561 Pneumatic A R. M OorC C C CIAS IA 3 Globe

. _ PK(B)

CHE-V494 None A A QorC C NA None NA 1hA Check empt; refer to step 1 (3)

CHA-UV580 Pneumatic A R, M 0 or C C C CIAS IA 1%A Gate Exempt; refer to step 1(5)

__ _ _ _ _ __ _ __ _ _ _ _ _ _ __ _ _ I PK (A ) _ _ _

CHA-UV715 Solenoid A R C C C CIAS PK(A) Y, Globe CHA-UV516 Pneumatic A R 0 C C CIAS IA 2 Globe SIAS PK(A)

CHB-UV523 Pneumatic A R. M 0 C C CIAS IA 2 Globe PK(B)

CHB-UV924 Solenoid A R C C C CIAS PK (B) Y2 Globe CHE-VM70 None A A C 0 or C NA None NA 3 Check xempt: refer to step 1(3)

CHA-HV524 Motor R M LO LO FAI None PH (A) 2 Globe Exempt; refer to step 1(5)

CHE-V854 Hand M M C C NA None NA  % Globe CHE-V835 None A A 0 OorC NA None NA 1 Y. Check CHB-HV255 Motor R M 0 O or C FAI None PH (B) 1 Y% Globe CL MCLEU58 NA NA NA C C NA None NA 8 %% Flange Passive device. No Impact due to SBO.

ILRT MCLEU62B MCLEU62C _ _

CP CPB-UVO05A Solenoid A R C C C CIAS PK (B) 8 Bfly Failure of AC power would result in closure of these valves.

Purge CPIAS CPA-UVO04A Solenoid A R C C C CIAS PK (A) 8 BWfly CPIAS CPA-UVO04B Solenoid A R C C C CIAS PK (A) 8 BWly I_ I ICPIAS Page 14 of 44

Enclosure Table 4, Containment Isolation Valves Page 2of8 System Valve Numbers Va Atuonr Actuaton Nom p Fa Acena Power Source Valve Valve Applicable steps of NUMARC 87-00. section 7.2.5 & other Oprtr Mode Mode ___Accident FiueSignal (ri) Sz i. yerfrne CP CPB-UVO05B Solenoid A R C C C CIAS PK (B) 8 B'fly ailure AC power would result in closure of these valves.

Purge CPIAS CPB-UV003A Motor A R LC C FAI CIAS PH (B) 42 B1lfly rocedurally locked Cosed. Exempt; step 1(1). NUMARC 87-00.

CPIAS Q/A 100 In Appendix I and Appendix J Q/A 7.1 (See Note 1)

CPA-UV002A Motor A R LC C FAI CIAS PH (A) 42 B'/fly CPIAS CPA-UVO02B Motor A R LC C FAI CIAS PH (A) 42 B3/fly CPIAS CPB-UV003B Motor A R LC C FAI CIAS PH (B) 42 BWIfly

_________ ~~~~~~ ~~ ~~~~~CPIAS DW DWE-V061 Hand M M LC C NA None NA 2 Globe Exempt; refer to step 1(4) and (5)

DWE-V062 _

FP FPE-V089 Hand M M LC C NA None NA 6 Gate Procedurally locked closed. Exempt; step 1(1). NUMARC 87-00, Q/A 100 In Appendix I and Appendix J QIA 7.1 (See Note 1)

FPE-VO90 None A A C C NA None NA 6- Check Exempt; refer to step 1(3)

GA AE-V015 None A A 0 C NA None NA 1 Check (N2) AA-UV002 Solenoid A R 0 C C CIAS PK (A) 1- Globe empt; refer to step 1 (5)

AE-V011 None A A C C NA None NA 1 Check AA-UV001 Solenoid A R C C C CIAS PK (A) 1 Globe GR RA-UV001 Motor A R 0 C FAI CIAS PH (A) 1 Globe RTD Vent RB-UV002 Solenoid A R 0 C C CIAS PK (B) 1 Globe HC HCB-UV044 Solenoid A R 0 O or C C CIAS PK (B) 1 Globe Rad. Mon. HCA-UV045 Solenoid A R 0 O or C C CIAS PK (A) 1 Globe HCB-UV047 Solenoid A R 0 OorC C CIAS PK (B) I Globe HCA-UV046 Solenoid A R 0 O or C C CIAS PK (A) 1 Globe HC HCA-HV074 Solenoid R R 0 0 0 None PK (A)  % Globe Press. Mon. HCB-HV075 Solenoid R R 0 0 0 None PK (B)  % Globe HCC-HV076 Solenoid R R 0 0 0 None PK (C)  % Globe HCD-HV077 Solenoid R R 0 0 0 None PK (D)  % Globe HP HPB-UV002 Motor A R C O or C FAI CIAS PH (B) 2 Globe H2 Control HPB-UVO04 Motor A R C O or C FAI CtAS PH (B) 2 Globe HPB-HV008A Solenoid R R C O or C C None PK (B) 1 Globe I HPA-V002 None A A C 0 or C NA None NA 2 Check Exempt; refer to step 1 (3)

HPA-UVO05 Motor A R C O or C FAI CIAS PH (A) 2 Globe Exempt; refer to step 1(5)

HPA-HV007B Solenoid R R C O or C C None PK (A) 1 Globe HPA-UV0023 Solenoid A R C O or C FC CIAS PK (A) YZWU1 Globe

_ 1 U2 &3 HPB-V004 None A A C O or C NA None NA 2 Check HPB-UV006 Motor A R C 0 or C FAI CIAS PH (B) 2 Globe HPB-HV008B Solenoid R R C O or C C None PK (B) 1 Globe HPA-UV001 Motor A R C O or C FAI CIAS PH (A) 2 Globe Page 15 of 44

Enclosure Table 4, Containment Isolation Valves Page 3 of 8 Valve Primary Secondary Valve posiAtin ESF Power Source Valve Valve Applicable steps of NUMARC 87-00, section 7.2.5 & other Sytm VlvI

_Mode ubr Operator Mode Nomal Accident olaiure Signal (Train) Size (in.) Type references HP HPA-UV003 Motor A R C O or C FAI CIAS PH (A) 2 Globe Exempt; refer to step 1 (5)

H2 Control HPA-HV007A Solenoid R R C O or C C None PK (A) 1 Globe HPA-UV0024 Solenoid A R C O or C FC CIAS PK (A) V U1 Globe

. _ _1U2 &3 IA IAE-V021 None A 0 C NA None NA 2 Check Exempt; refer to step 1 (3)

AA-UV002 Solenoid A R 0 C C CSAS PK (A) 2 Globe Exempt; refer to step 1 (5)

IAE-V073 None A A C C NA None NA 3 Check Exempt: refer to step 1 (3)

IAE-V072 Hand M M LC C NA None NA 3 Globe Procedurally locked closed. Exempt; step 1 (1). NUMARC 87-00,

_ _Q/ _A 100 In Appendix I and Appendix J Q/A 7.1 (see note 1)

NC NCE-V118 None A A 0 C NA None NA 10 Check Exempt :referto step 1 (3)

NCB-UV401 Motor A R 0 C FAI CSAS PH (B) 10 BFly Exempt refer to step 1 (4)

NCB-UV403 Motor A R 0 C FAI CSAS PH (B) 10 BIFly NCA-UV402 Motor A R 0 C FAI CSAS PH (A) 10 B Fly NCE-PSV0617 Safety A M C C C None NA %x 1 Relief Inside containment - outer Isolation UV-402 would be closed. The SBO would not result In tifting PC PCE-V071 Hand M M LC C NA None NA 4 Gate Procedurally locked dosed. Exempt; step 1 (1). NUMARC 87-00, PCE-V070 Hand M M LC C NA None NA 4 Gate t:A 100 in Appendix I and Appendix J Q/A 7.1 (see note 1)

PCE-V075 Hand M M ILC C NA None NA 4 Gate PCE-V076 Hand M M LC C NA None NA 4 Gate RD RDA-UV023 Motor A R 0 C FAI CIAS PH (A) 3 Gate Athough the Inner valves remain open, outer valve, (UV024) would lose to safe position when AC power Is lost. Single failure does not pply see QIA 101 Appendix I RDB-UV024 Pneumatic A R 0 C C CIAS IA 3 Gate ails close on loss of power PK(B) _

RDB-UV407 Solenoid A R C C FC CIAS PK (B) A Globe Exempt; refer to step 1 (3)

SG SGB-UV132 Hydraulic A R 0 C C MSIS Accumulator 24 Gate Valves are exempt since the SG tubes provide the pressure Feedwater SGB-UV137 boundary between primary and secondary and act as containment SGA-UV174 boundary. Lack of isolation would not result In breach of SGA-UV177 _ containment. Normal leakages from primary to secondary would be SGE-V003 None A A 0 C NA None NA 24 Check imited. Water level In secondary would reduce any release as a SGE-VO06 result of normal leakage though this pathway. Special application of GE-V007 closed- loop system Step 1 Item 4.

SGE-V005 SGE-V652 None A A 0 C C None NA 8 Check SGE-V653 SGE-V642 SGE-V693 GB-UV130 Pneumatic A R 0 C O or MSIS IA 8 Gate GB-UV135 C(e) GA PK(B) _

Page 16 of 44

Enclosure Table 4, Containment Isolation Valves Paqe 4 of 8 Valve PrimaryI Secondary VIve positi ESF un Power Source Valve Valve Applicable steps of NUMARC 87-00, section 7.2.5 & other I IOperator I Mode Mode u Normal Accident Failure I SinaI (Train)

_ Size (in Type references SG SGB-HV200 Solenoid A R C C FC CIAS PK (B) Plug Valves are exempt since the SG tubes provide the pressure Feedwater MSIS boundary between primary and secondary and act as containment SGA-UV172 Pneumaticl A R I C IOor MSIS IA 8 Gate boundary. Loss of Isolation would not result In breach of SGA-UV175 1C(e I containment. Normal leakages from primary to secondary would be I 1.. _ _ _ _C e) _ _ _ PK(A) _ _ _

limited. Water level in secondary would reduce any release as a SGB-HV201 Solenoid A R C C FC CIAS PK (B)  % IPlug result of normal leakage though this pathway. Special application of MSIS closed- loop system Step 1 item 4.

-- - -- 1* - 1 - t---t-------t--1. - 9 - t --

St SG3E-UV17U Hydraulic A R 0 C C I MSIS I Accumulator 28 Gate Main Steam SGE-UV171 SGE-UV180 SGE-UV181 SGE-PSV691 Safety A NA C C C None NA 6 Safety SGE-PSV692 SGE-PSV694 SGE-PSV695 SGE-PSV575 Safety A NA C C C None NA 6 Safety SGE-PSV576 SGE-PSV557 SGE-PSV558 .

SGE-PSV574 Safety A NA C C C None NA 6 Safety SGE-PSV577 SGE-PSV556 SGE-PSV559 .

SGE-PSV573 Safety A NA C C C None NA 6 Safety SGE-PSV578 SGE-PSV555 SGE-PSV560 SGE-PSV572 Safety A NA C C C None NA 6 Safety SGE-PSV579 SGE-PSV554 SGE-PSV561 SGA-UV134 Motor A R C O/C FAI AFAS-1 PK (A) 6 Gate SGA-UV138 AFAS-2 SGA-UV134A Solenoid A R C O/C FC AFAS-1 PK (A) 1 Globe SGA-UVI38A _ AFAS-2 SGA-HV184 Pneumatic R M C O/C FC None(d) Accumulator 12 Globe SGB-HV178 IA SGB-HV185 PK (A, B. C, SGA-HV179 D)

SGE-UV169 Pneumatic A R C C FC MSIS PK (A, B) 4 Gate SGE-183 _ _

SGA-UV1133 Solenoid A R 0 C C I MSIS PK (A) 1 IGlobe SGA-UV1 134 Page 17 of 44

Enclosure Table 4, Containment Isolation Valves Page5of8 valve Primary Secondary Vave position ESF Power Source Valve Valve Applicable steps of NUMARC 87-00, section 7.2.5 &other System Valve Numbers Operator Actuation Actuation Noroal Post- AtuatinPowrTSourceSie nalve references Oprtr Mode Mode NomlAccident FiueSigna (Tin Szein)T'ereece SG SGB-UV1135A Solenoid A R 0 C C MSIS PK(B) 1 Globe Valves are exempt since the SG tubes provide the pressure Main Steam SGB-UV1135B boundary between primary and secondary and act as containment SGB-WV1136A undary. Loss of Isolation would not result in breach of GB-UV1136B containment. Normal leakages from primary to secondary would be GE-V603 Hand M M LC C NA None NA lobe imited. Water level in secondary would reduce any release as a SGE- V611 result of normal leakage though this pathway. Special application of SG SGA-UV211 Solenoid A R 0 C FC MSIS PK (A)  % Plug closed- loop system Step 1 item 4.

Blowdown AFAS-1 Sample AFAS-2 SIAS SGB-UV228 Solenoid A R 0 C FC PK (B) %Z Plug SGA- V204 Solenoid A R 0 C FC MASIS PK (A) ', Plug AFAS-1 AFAS-2 SIAS SGB-UV219 Solenoid A R 0 C FC PK (B) Y. Plug SGB-UV226 Solenoid A R 0 C FC MSIS PK (B) /, Plug AFAS-1 AFAS-2 SIAS SGA-UV227 Solenoid A R 0 C FC PK(A) '2 Plug SGA-UV220 Solenoid A R 0 C FC MSIS PK(A) %A Plug AFAS-1 AFAS-2 SIAS SGB-UV221 Solenoid A R 0 C FC PK (B) 2 Plug GB-UV224 Solenoid A R 0 C FC MSIS PK (B) '2 Plug AFAS-1 AFAS-2 SIAS SGA-UV225 Solenoid A R 0 C FC PK (A) /, Plug SGB-UV222 Solenoid A R 0 C FC MSIS PK (B) %A Plug AFAS-2 AFAS-2 SIAS

_SGA-UV223 Solenoid A R 0 C FC PK (A) /, Plug SG SGA-UV500P Pneumatic A R 0 C FC MSIS IA 6 Gate Blowdown AFAS-1 PK (A)

AFAS-2

_ _ SIAS SGB-UV500Q Pneumatic A R 0 C FC IA 6 Gate

___ _PK (B) _

_SGE-V293 Hand M M LC C NA None NA 1 Globe Page 18 of 44

Enclosure Table 4, Containment Isolation Valves Paae 6 of 8 Valve Primary Secondary Valve position ESF Power Source Valve Valve Applicable steps of NUMARC 87.00. section 7.2.5 & other System Valve Numbers Operator Actuation Actuation Normal Post- Failure Actuation (Train) Size (in.) T references Oprtr Mode Mode NO Accident aueSignal Crl )T'erfrne SG SGB-UV500R Pneumatic A R 0 C FC MSIS IA 6 Gate Valves are exempt since the SG tubes provide the pressure Blowdown AFAS-1 PK (B) boundary between primary and secondary and act as containment AFAS-2 oundary. Loss of IsolatIon would not result In breach of

_ SIAS contalnment. Normal leakages from primary to secondary would be SGA-UV500S Pneumatic A R 0 C FC IA 6 Gate imited. Water level In secondary would reduce any release as a PK (A) esult of normal leakage though this pathway. Special application of SGE-V294 Hand M M LC C NA None NA 1 Globe osed- loop system Step 1 Item 4.

St SIE-V113 None A A C 0 NA None NA 3 Check Exempt: refer to step 1 (3)

HPSI SIB-UV616 Motor A R. M C 0 FAI SIAS PH (B) 2 Globe Exempt; refer to step 1 (5)

SIA-UV617 Motor A R. M C 0 FAI SIAS PH (A) 2 Globe .-

SIE-V123 None A A C 0 NA None NA 3 Check empt; refer to step 1 (3)

SIB-UV626 Motor A R, M C 0 FAI SIAS PH (B) 2 Globe Exempt; refer to step 1(5)

SIA-UV627 Motor A R. M C 0 FAI SIAS PH (A) 2 Globe SIE-V133 None A A C 0 NA None NA 3 Check empt; refer to step 1 (3)

SIB-UV636 Motor A R, M C 0 FAI SIAS PH (B) 2 Globe Exempt; refer to step 1 (5)

SIA-UV637 Motor A R. M C 0 FAI SIAS PH (A) 2 Globe SIE-V143 None A A C 0 NA None NA 3 Check SiB-UV646 Motor A R. M C 0 FAI SIAS PH (B) 2 Globe

_SiA-UV647 Motor A R. M C 0 FAI SIAS PH (A) 2 Globe Si SIA-V164 None A A C 0 NA None NA 10 Check Exempt; refer to step 1 (3)

Containment SIA.UV672 Motor A R LC 0 FAI CSAS PH (A) 8 Gate rocedurally locked closed. Exempt; step 1 (1). NUMARC 87-00.

Spray _ Q/A 100 In Appendix I and Appendix J Q/A 7.1 (See Note 1)

SIB-V165 None A A C 0 NA None NA 10 Check Exempt; refer to step 1(3)

SIB-UV671 Motor A R LC 0 FAi CSAS PH (B) 8 Gate rocedurally locked closed. Exempt; step 1 (1). NUMARC 87-00,

__ Q/A 100 In Appendix I and Appendix J Q/A 7.1 (See Note 1)

Si SIE-V114 None A A C 0 NA None NA 12 Check Exempt; refer to step 1 (3)

LPSI SIB-UV615 Motor A R. M C FAI SiAS PH (B) 12 Globe SF,required formitigation of event. Part of extended containment Poundarv.

SIE-V124 None A A C 0 NA None NA 12 Check empt; refer to step 1 (3)

SiB-UV625 Motor A R. M C 0 FAI SIAS PH (B) 12 Globe SF, required for mitigation of event. Part of extended containment

.__ oundary.

SIE-V134 None A A C 0 NA None NA 12 Check empt; refer to step 1 (3)

SIA-UV635 Motor A R. M C 0 FAI SIAS PH (A) 12 Globe SF, required for mitigation of event. Part of extended containment

- - ___ ndary.

SIE-V144 None A A C 0 NA None NA 12 Check xempt; refer to step 1 (3)

SIA-UV645 Motor A R. M C 0 FAI SIAS PH (A) 12 Globe ESF, required for mitigation of event. Part of extended containment Si SIA-UV673 Motor A R. M C 0 FAI RAS PH (A) 24 B-FIy boundary.

Recirc SIA-UV674 Motor A R, M C 0 FAI RAS PH (A) 24 B Fly IA-PSV1 51 Safety A NA C C C None NA  % Safety Exempt; refer to step 1 (5)

SIA-UV708 Solenoid A R C C C CIAS PK (A) /, Globe Page 19 of 44

Enclosure Table 4, Containment Isolation Valves Page 7 of 8 Primary Secondary Valve position ESF Valve Auion Acon postl ActatonPower Source Valve Valve Applicable steps of NUMARC 87-00, section 7.2.5 & other System Valve Numbers Operator AcMuoden ActuaMdon Normal APdent Failure AcStignaln (Train) Size (in.) Type references Si SIB-UV675 Motor A R,M C 0 FAI RAS PH (B) 24 B'Fly ESF. required for mitigation of event. Part of extended containment Recirc SIB-UV676 Motor A R. M C 0 FAI RAS PH (B) 24 B'FIv boundary.

SIB-PSV140 Safety A NA C C C None NA  % Safety xempt: refer to step 1 (5)

Si ID-UV654 Motor R R LC 0 or C FAI None PK (D) 16 Gate Procedurally locked dosed. Exempt; step 1 (1). NUMARC 87-00.

SDC SIB-UV656 Motor R M LC O or C FAI None PH (B) 16 Gate Q/A 100 In Appendix I and Appendix J Q/A 7.1 (See Note 1)

SIB-HV690 Motor R M LC OorC FAI None PH (B) 10 Globe SIB-PSV189 Safety A NA C C C None NA 6 Safety Not expect to lift for this event SIC-UV653 Motor R R LC OorC FAI None PK(C) 16 Gate Procedurallylocked dosed. Exempt; step 1 (1). NUMARC 87-00, SIA-UV655 Motor R M LC O or C FAI None PH (A) 16 Gate PA 100 In Appendix I and Appendix J Q/A 7.1 (See Note 1)

SIA-HV691 Motor R M LC 0 or C FAI None PH (A) 10 Globe SIA-PSV179 Safety A NA C C C None NA 6 Safety Not expected to lift for this event Si SIA-UV682 Pneumatic A R C C C SIAS IA 2 Globe Exempt; refer to step 1 (5)

Fill & Drain PK(A)

SIE-V463 Hand M M LC C NA None NA 2 Globe SIE-PSV474 Safety A NA C C C None NA / Safetv Si SIA-V523 None A A C 0 NA None NA 3 Check Exempt; refer to step 1 (3)

Long Term SIC-HV321 Motor R M LC 0 FAI None PK (C) 3 Globe ESF, required for mitigation of event. Part of extended containment Recirc boundary SIB-V533 None A A C 0 NA None NA 3 Check Exempt; refer to step 1 (3)

SID-HV331 Motor R M LC 0 FAI None PK (D) 3 Globe Procedurally locked closed. Exempt; step 1 (1). NUMARC 87-00,

_ Q/A 100 In Appendix I and Appendix J QIA 7.1 (See Note 1)

SS SA-UV204 Solenoid A R C C C CIAS PK (A)  % Plug Exempt; refer to step 1 (5)

SSB-UV201 Solenoid A R C C C CIAS PK (B)  % Plug SSA-UV205 Solenoid A R C C C CIAS PK (A)  % Plug SSB-UV202 Solenoid A R C C C CIAS PK (B)  % Plug SSA-UV203 Solenoid A R C C C CIAS PK (A)  % P SSB-UV200 Solenoid A R C C C CIAS PK (B)  % Plug WC CE-V039 None A A 0 C NA None NA 10 Check Exempt: refer to step 1 (3)

CB-UV063 Motor A R 0 C FAI CIAS PH (B 10 Gate Exempt; refer to step 1 (4)

CB-UVO61 Motor A R 0 C FAI CIAS PH (B) 10 Gate WCA-UV062 Motor A R 0 C FAI CIAS PH (A) 10 Gate Air locks (L-11, ZCNM01 NA M M C C NA None NA N/A N/A Passive, not required to be evaluated L-3) CZCNMO2 Equipment ZCNMO3 NA M M C C NA None NA N/A N/A Hatch (L-2) I .I Fuel Transfer MPCEU53 NA NA NA C C NA None NA 36 Flange Tube Electrical EXXXZO1 thru Penetrations EXXXZ91 NA NA NA NA NA NA NA NAN NA Page 20 of 44

Enclosure Table 4, Containment Isolation Valves Page 8 of 8 Note 1: The handweels for these valves are chained and locked, ifvalve is motor operated, the motors do not have a mechanical lock, therefore the lock is provided at source of power (breakers are physically locked by a mechanical device).

NA not applicable MSIS ain steam isolation signal pen SAS ontainment spray actuation signal C losed PIAS ontainment purge isolation actuation signal A utomatic FAS FW actuation signal R emote operation 1AS afety injection actuation signal M manual local operation _RAS ecirculation actuation signal DU data currently unavailable _CIAS ntainment Isolation actuation signal LO ocked open _IA Instrument air system.

LC ocked closed PK 125 VDC Power, Class 1E FO fail open PH 120/480 VAC Power, Class 1E FC fail closed GA Service Gas, Nitrogen FAI fail-as-is _

Page 21 of 44

Enclosure

7. Reactor Coolant Inventory Loss Sources of expected reactor coolant inventory loss during the SBO event include RCS leakage (I1 gpm perTS 3.4.14) and losses due to RCP seal leakage (25 gpm/RCP per NUMARC 87-00). Analysis of the RCS during SBO indicates that expected rates of reactor coolant inventory loss do not result in the core uncovering in the first hour or the subsequent 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> of coping using AAC power source. Analysis further indicates that RCS makeup systems beyond those currently available under DBEs are not required. Sufficient head exists to maintain core cooling under natural circulation.

SBO scenarios conditions were simulated with the CENTS code. The analysis supports a determination of the plant's capability to cope for up to 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> under SBO conditions. The analysis presented here is initiated from hot full power conditions (3990 MWt) with the TS 3.4.14 maximum allowed RCS leakage of 11 gpm. Onset of SBO conditions are assumed to immediately cause RCP, turbine, and reactor trips, and failure of the RCP seals resulting in an additional leakage of 25 gpm/RCP. The following is a brief description of assumptions used for analysis the design bases SBO event.

Decay heat used is based on ANSI/ANS-5.1 1979, final decay heat plus 2 sigma.

The CENTS code models the heat loss from the pressurizer, the reactor vessel upper head, the balance of the RCS, and from the secondary side of each SG.

Modeling heat loss is conservative since it would worsen the cooldown of the RCS during first hour and maximize the phenomenon of loss of subcooling.

Only safety related systems are used to mitigate the event (HPSI, SDC system (SDCS), EWS, SPS, AFW, pressurizer vent valves, main steam safety valves (MSSVs), and ADVs).

No operator action for RCS inventory loss is assumed within the first hour of the event. The following operator actions are assumed after actuation of the AAC power source at one hour.

a. Control of cooldown using ADVs.

b. The AFW system is adjusted to maintain SG level.

c. The HPSI flow is delivered to maintain RCS inventory, subcooling, and natural circulation.

d. At 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> - operators adjust ADVs for approximately a 30 0F/hr cooldown and maintain pressure in the RCS using the pressurizer vent valve.

Table 5 demonstrates the capability to control RCS inventory, pressure, and temperature; and achieve SDC entry conditions at 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />. Figure 3 thru Figure 15 provide additional information on performance of RCS and secondary systems. It is therefore concluded that the ability to maintain adequate RCS inventory to ensure that the core can be cooled is achieved using the existing safety systems for 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />. The rates of coolant inventory loss under SBO Page 22 of 44

Enclosure conditions do not result in core uncovery and the station can cope with a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> duration SBO event.

Procedure changes for actions required to ensure RCS inventory are required to support a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping strategy. These changes are described in Sections C and E.

Table 5 SBO Design Case (111 gpm RCS and RCP leakage) Controlled with HPSI Sequence of Events Time, sec Parameter Value SBO conditions arise.

0 Total RCP seal + TS 3.4.14 max. allowed leakage assumed, gpm. 111 Turbine I reactor trip.

10 MSSVs open.

800 AFW flow is initiated as a result of on low SG level, lbI,/sec. 93 Operator opens ADVs on each SG to close MSSVs and approach 570 'F Tcold-3600 Operator adjusts AFW to maintain SG level/match ADV flow.

HPSI pump is loaded onto the GTG-energized bus, and flow initiates (and is controlled not to exceed 126 gpm) as RCS pressure drops below shutoff head, psia. 1715 Operator opens the ADVs on each SG to initiate a - 30 0F/hr 14400 cooldown, and is adjusted hourly to sustain cooldown.

Operator opens the pressurizer vent valve to limit the increase in subcooling.

- 40000 SDC entry pressure is achieved, psig. 435

- 43000 SDC entry temperature achieved, "F. <350 46800 Operator adjusts ADVs to terminate the cooldown. --

48000 Operator controls HPSI (S405 gpm) to limit pressurizer level increases.

Page 23 of 44

Enclosure Figure 3 Pressurizer Pressure versus Time 2500-2000 - -

1500 40 40 So 0

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Mme, hours Page 24 of 44

Enclosure Figure 4 Level in Pressurizer versus Time 25 -

20 15 10 2 0 2 4 6 8 10 12 14 16 Time, hours Page 25 of 44

Enclosure Figure 5 Subcooling in Hot Leg #1 versus Time 120-C

= 60 C')

40 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ .

I___ _ _ _ _ _ _ _ _ _ _

0 2 4 6 8 10 12 14 16 Time, hours Page 26 of 44

Enclosure Figure 6 Subcooling in Upper Head versus Time 100 90 _ _ _

80-70 l IL. 60 A C;

.gc 50

.0 U, 40 10 I/

0 V

0 2 4 6 8 10 12 14 16 Tnme, hours Page 27 of 44

Enclosure Figure 7 Temperature in Hot Leg #1 versus Time 700 600-500 LL e 400 E!

E 03 E300

XTI 200 100 0

0 2 4 6 8 10 12 14 16 Time, hours Page 28 of 44

Enclosure Figure 8 Total AFW Flow Rate versus Time IWu 90 - I _ _ _ __ _ _

80 -- - __ __

70 - _ = = = = = = =

U 0

6 0 - I_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

-D I

40 - - _ . -- I_

30 - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

~~~I ltr 1 - - _ _ _ _ _ _ _

0 - - 1 0 2 4 6 8 10 12 14 16

'ime, hours Page 29 of 44

Enclosure Figure 9 Total Integrated AFW Flow versus Time 2500000 2000000 E

-9 3 1500000-U.

0 Lo 1000000-0) 0v 500000- - __ _ __ _ _ __

0-0 2 4 6 8 10 12 14 16 Time. hours Page 30 of 44

Enclosure Figure 10 Pressurizer Vent Flow Rate versus Time 1.0 0.9 '

0.8- \

0.7 06

.0

-J a60.5 0.4 "-

cr - -

0 2 4 6 8 10 12 14 16 Time, hours Page 31 of 44

Enclosure Figure 11 SG #1 Downcomer Level versus Time 45 -

40 35 -

30 -

t: 25-a)

-' 20-15 -

I I 10 -

5 0o 2 4 6 8 10 12 14 16 Time, hours Page 32 of 44

Enclosure Figure 12 SG #1 Pressure versus Time 1400 1200 = _=-

1000 IF 800 0*

0 2 4 6 8 10 12 14 16 Time, hours Page 33 of 44

Enclosure Figure 13 SG #1 Steam Dome Temperature versus Time 700-600-500 a,

00 200-100 0

0 2 4 6 8 10 12 14 16 Time, hours Page 34 of 44

Enclosure Figure 14 Total HPSI Pump Flow Rate versus Time I20 -

ha 12 -I _ __ I __ _ __ __ _ __ _ _ _ _

c a

a. 8-E a-6-

4-2-

n I-I-0 2 4 6 8 10 12 14 16 Time, hours Page 35 of 44

Enclosure Figure 15 Hot Leg #1 Flow Rate versus Time 30000 25000 20000 IL 0

4; 15000 (a

10000 5000 0 _ _

0 2 4 6 8 10 12 14 16 Time, hours Page 36 of 44

Enclosure

8. Emergency Lighting The emergency lighting system with eight hour battery-backed power supplies provides illuminating requirements where local manual operation is required within the power block. This lighting illuminates automatically upon a loss of AC power.

After 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, the A train essential lighting is powered by the GTGs.

No plant or procedure changes are required to implement a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping strategy.

9. Communications The primary modes of communication during an SBO are the telephone system, the plant 2-way radio system, and the sound powered phone system. The telephone system has at least a 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> battery capability. The 2-way radio system has a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> battery system and will be transferred to the GTGs. The sound powered phone system requires no external power source to operate.

No plant or procedure changes are required to implement a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping strategy.

C. PROCEDURE

S NUMARC 87-00, Section 4.2, provides guidelines for development of operating procedures for response to an SBO event. Palo Verde procedures required to support a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> SBO period are as follows:

1. AC Power Restoration A 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping period does not impact Black-Start System Restoration. The Blackout procedure will be revised for a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping period.

2. Severe Weather Procedures The Acts of Nature procedure will not be impacted by the SBO duration to 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />.

3. SBO Response Procedures

a. The Blackout procedure will be revised to address the following changes for the 16-hour coping strategy:

Depressurize the RCS using the pressurizer vent system for RCS pressure control as an alternative to auxiliary spray.

• Initiate a cooldown to SDC entry conditions within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

• Place spent fuel pool cooling in service within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

• Direct maintenance personnel to connect the control air system will be supplemented and place in service within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> as neccessary.

• Place SDC in service within 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />.

b. The GTG operation and loading procedures will be revised for a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> SBO.

Page 37 of 44

Enclosure

c. Procedures will be developed or revised as necessary to address storage, maintenance, testing, and operation of the supplemented control air system to support 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> of operation of the ADVs.

d. Emergency Plan Implementing procedures will be revised to address the effects of an SBO for 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />. Emergency Response Organization responsibilities include connecting and operating the supplemented control air system as necessary.

4. Coldstarts Procedures for starting the EDGs are not impacted by the 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping period.

5. Emergency AC Power Availability Methods for emergency diesel generator availability are not impacted by the 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping period.

D. QUALITY ASSURANCE AND SPECIFICATION FOR NONSAFETY RELATED STATION BLACKOUT EQUIPMENT The nonsafety related equipment added to cope with the SBO condition will meet the quality assurance requirements of Appendices A and B to Regulatory Guide (RG) 1.155 for PVNGS. Table 6 outlines the PVNGS position regarding RG 1.155.

Page 38 of 44

Enclosure Table 6, Regulatory Guide 1.155 - Station Blackout Revision 0, August 1988, Compliance Table .

Paqe 1 of 4 RG 1.155 PVNGS Regulatory Position Applicable Position

.__ .Sections ONSITE EMERGENCY AC POWER SOURCES 1.0 Emergency Diesel Generator Target Reliability Levels 1.1 No exception taken Reliability Program 1.2 No exception taken Procedures for Restoring Emergency AC Power 1.3 No exception taken OFFSITE POWER 2.0 No exception taken ABILITY TO COPE WITH A SBO 3.0 Exception taken, 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping time is Minimum Acceptable SBO Duration Capability. 3.1 based on a voluntary license condition rather than an evaluation of the factors discussed In section 3.1.

Evaluation of Plant-Specific SBO Capability 3.2 Exception taken, The NSSS and secondary performance, condensate volume are The evaluation should be performed assuming that the SBO event occurs while the reactor is operating calculated using the decay heat used for the at 100% rated thermal power and has been at this power level for at least 100 days. 3.2.1. 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> analyses discussed herein is based on the ANSIIANS-5.1 1979 decay heat curve, plus a 2 sigma uncertainty at equilibrium.

The capability of all systems and components necessary to provide core cooling and decay heat removal following a SBO should be determined, including station battery capacity, condensate . storage tank 3.2.2 No exception taken capacity, compressed air capacity, and instrumentation and control requirements.

The ability to maintain adequate reactor coolant system inventory to ensure that the core is cooled should be evaluated, taking into consideration; shrinkage, leakage from pump seals, and Inventory loss 3.2.3 No exception taken - Methodology used Is from letdown or other normally open lines dependent on ac power for isolation.

The design adequacy and capability of equipment needed to cope with a SBO for the required duration and recovery period should be addressed and evaluated as appropriate for the associated environ-' 3.2.4 different than NUMARC 87-00.

mental conditions.

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Enclosure Table 6, Regulatory Guide 1.155 - Station Blackout Revision 0, August 1988, Compliance Table Paae 2 of 4 RG 1.155 PVNGS Regulatory Position Applicable Position No exception taken - It has been Consideration should be given to using available non-safety-related equipment, as well as safety-related demonstrated that in onset of SBO, event equipment; to cope with a SBO provided such equipment meets the recommendations of Regulatory the station can cope for duration of 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> Positions 3.3.3 and 3.3.4. Onsite or nearby AAC power sources that are independent and diverse from without any AC sources until the AAC power the normal Class 1E emergency ac power sources (e.g., gas turbine, separate diesel engine, steam 3.2.5 sources are started and lined up to operate supplies) will constitute an acceptable SBO coping capability provided an analysis is performed that for the 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> required duration.

demonstrates the plant has this capability from the onset of SBO until the MC power source or sources Based on regulatory guidelines, it is are started and lined up to operate all equipment necessary to cope with SBO for the required duration. assumed that only one of three units at the Palo Verde site would experience SBO.

Consideration should be given to timely operator actions Inside or outside the control room that would increase the length of time that the plant can cope with a SBO provided It can be demonstrated that 3.2.6 No exception taken these actions can be carried out in a timely fashion. -

The ability to maintain appropriate containment Integrity" should be addressed. 'Appropriate containment integrity" for SBO means that adequate containment integrity is ensured by providing the capability, independent of the preferred and blackout unit's onsite emergency ac power supplies, for 3.2.7 No exception taken valve position indication and closure for containment isolation valves that may be in the open position at the onset of a SBO.

Modifications To Cope with SBO. 3.3 If, after considering load shedding to extend the time until battery depletion, battery capacity must be No exception taken. Batteries have the extended further to meet the SBO duration recommended in Regulatory Position 3.1, it is considered capacity to serve the required loads for one acceptable either to add batteries or to add a charging system for the existing batteries that is 3.3.1 hour, without additional equipment or load independent of both the offsite and the blacked-out unit's onsite emergency ac power systems, such as shedding, until charging is restored from the a dedicated diesel generator. MC source.

Page 40 of 44

Enclosure Table 6, Regulatory Guide 1.155 - Station Blackout Revision 0, August 1988, Compliance Table Page 3 of 4 RGI1.155 PVNGS Regulatory Position Applicable Position

. _ Sections If the capacity of the condensate storage tank Is not sufficient to remove decay heat for the SBO duration recommended in Regulatory Position 3.1, a system meeting the requirements of Regulatory No exception taken. Plant CST has Position 3.5 to resupply the tank from an alternative water source is an acceptable means to increase its 3.3.2 sufficient volume.

capacity provided any power source necessary to provide additional water is independent of both the offsite and the blacked-out unit's onsite emergency ac power systems.

If the compressed air capacity Is not sufficient to remove decay heat and to maintain appropriate event would re u aTre lddtionger duration containment integrity for the SBO duration recommended in Regulatory Position 3.1, a system to provide eventnwo lrequirelait ofta sufficient capacity from an alternative source that meets Regulatory Position 3.5 is an acceptable means 3.3.3 supplemental control air system to aid to increase the air capacity provided any power source necessary to provide additional air Is current design of nitrogen supply for independent of both the offsite and the blacked-out unit's onsite emergency ac power systems. coprplance after installalion of this sbstem A system is required for primary coolant charging and makeup, reactor coolant pump seal cooling or injection, decay heat removal, or maintaining appropriate containment integrity specifically to meet the SBO duration recommended in Regulatory Position 3.1, the following criteria should be met:

1. The system should be capable of being actuated and controlled from the control room, or if other means of control are required, it should be demonstrated that these steps can be carried out in a timely 3.3.4 No exception taken.

fashion, and

2. If the system must operate at 10 minutes of a loss of all ac power, it should be capable of being actuated from the control room.

Page 41 of 44

Enclosure Table 6, Regulatory Guide 1.155 - Station Blackout Revision 0, August 1988, Compliance Table Page 4 of 4 _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _

RG 1.155 PVNGS Regulatory Position Applicable Position Sections _ ___

If an AAC power source is selected specifically for satisfying the requirements for SBO, the design should meet the following criteria:

1. The AAC power source should not normally be directly connected to the preferred or the blacked-out unit's onsite emergency ac power system.

2. There should be a minimum potential for common -cause failure with the preferred or the blacked-out unit's onsite emergency ac power sources. No single-point vulnerability should exist whereby a weather-related event or single active failure could disable any portion of the blacked-out unit's onsite emergency ac power sources or the preferred power sources and simultaneously fail the AAC power.

3. The MC power source should be available in a timely manner after the onset of SBO and have 3.3.5 No exception taken.

provisions to be manually connected to one or all of the redundant safety buses as required. The time. .

required for making this equipment available should not be more than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> as demonstrated by test.

If the MC power source can be demonstrated by test to be available to power the shutdown buses at 10 minutes of the onset of SBO, no coping analysis is required.

4. The AAC power source should have sufficient capacity to operate the systems necessary for coping with a SBO for the time required to bring and maintain the plant in safe shutdown.

5. The MC power system should be inspected, maintained, and tested periodically to demonstrate operability and reliability. The reliability of the MC power system should meet or exceed 95 percent as determined in accordance with NSAC-108 or equivalent methodology.

If a system or component is added specifically to meet the recommendations on SBO duration in Regulatory Position 3.1, system walkdowns and initial tests of new or modified systems or critical components should be performed to verify that the modifications were performed properly. Failures of 3.3.6 No exception taken.

added components that may be vulnerable to Internal or external hazards within the design basis (e.g.,

seismic events) should not affect the operation of systems required for the design basis accident.

A system or component added specifically to meet the recommendations on SBO duration in Regulatory Position 3.1 should be inspected, maintained, and tested periodically to demonstrate equipment 3.3.7 No exception taken.

operability and reliability.

Procedures and Training To Cope with SBO.

Procedures and training should include all operator actions necessary to cope with a SBO for at least the 3.4 No exception taken.

duration determined according to Regulatory Position 3.1.

Quality Assurance and Specification Guidance for SBO Equipment That Is Not Safety-Related. 3.5 No exception taken.

Page 42 of 44

Enclosure E. IMPLEMENTATION Modifications required to support a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping period include:

• Supplement the control air system, to support operation of the ADVs for 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />. The gas source will be purchased, stored, and maintained per the requirements of RG 1.155.

Procedures required to be changed to support a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping period include:

• Blackout,40EP-9EO08, 40DP-9AP13

• GTG operation and loading, 400P-9GT01, 550P-OGT01, 550P-OGT02

• Operations Support Center Actions, EPIP-02.

Schedule to implement a 16 hour1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> coping strategy:

• Within 6 months of approval by the NRC.

REFERENCES Reference 1 (Letters submitted to NRC by APS regarding the current SBO evaluation) 1.1 Letter 161-01842, dated April 14,1989, D. B. Karner (APS) to USNRC, "Response to Station Blackout Rule."

1.2 Letter 161-03025, dated March 26,1990, from W. F. Conway (APS) to USNRC, "Palo Verde Nuclear Generating Station (PVNGS) Units 1,2, and 3 Submittal of Supplemental Information on Station Blackout."

1.3 Letter 161-04146, dated August 31,1991, from W. F. Conway (APS) to USNRC, "Revised Response to the Station Blackout Rule (10 CFR 50.63)".

1.4 Letter 102-02300, dated October 2, 1992, from W. F. Conway, (APS), to USNRC, " Response to NRC Comments on Periodic Testing of Alternate AC (AAC) Sources (Supplementary Safety Evaluation for Station Blackout)".

1.5 Letter 161-04684, dated March 20,1992, from W. F. Conway, (APS), to USNRC, "Response to the NRC Station Blackout Safety Evaluation Recommendations."

1.6 Letter 102-02798, dated January 25,1994, from W. F. Conway (APS) to USNRC, "Current Status of Station Blackout (SBO) Alternate AC Modifications."

Reference 2 (Letters from NRC to APS regarding current SBO evaluation) 2.1 Letter dated December 11, 1990, from USNRC to W. F. Conway, APS, "Clarification of Information on Station Blackout."

2.2 Letter dated February 11, 1992, from USNRC to W. F. Conway, APS, "Station Blackout Safety Evaluation PVNGS."

Page 43 of 44

Enclosure 2.3 Letter dated July 28,1992, from USNRC to W. F. Conway, APS, "Supplementary Safety Evaluation for Station Blackout - Palo Verde Nuclear Generating Station."

2.4 Letter dated January 4,1993, from USNRC to W. F. Conway (APS),

"Station Blackout Final Supplementary Safety Evaluation."

2.5 Letter dated April 14, 1993, from USNRC to W. F. Conway (APS), "Station Blackout Final Supplementary Safety Evaluation."

ReferE once 3 NUMARC 87-00, Guidelines and Technical Bases for NUMARC Initiatives Addressing SBO at Light Water Reactors.

Refer( mnce 4 Regulatory Guide 1.155: Station Blackout, Revision 0, August 1988.

Page 44 of 44