Text

Operator Action Summary Data Sheet & Post-Initiator Human Error Probability Calculation Worksheet HRA Worksheet 1
	ML20113C514
Person / Time
Site:	San Onofre
Issue date:	06/18/1996
From:	Chung G, Motamed M, Rolda Z; SOUTHERN CALIFORNIA EDISON CO.
To:	;
Shared Package
ML20113C504	List: ML20113C499; ML20113C508; ML20113C514; ML20113C519;
References
	NUDOCS 9607010294
	Download: ML20113C514 (42)
	v • d • e

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OPERATOR' ACTION: ' Operator to Stokthe affected or all Circulating Water System Pumpsin 10 Minutes Without a Flood. Watch .

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- BASIC EVENT / EVENT TREE:. OP / SO2CW1, SO2CW3 & SO2CW4 - Barrier' Event Tree -

OPERATOR ACTION

SUMMARY

DATA SHEET AND POST-INITIATOR HUMAN ERROR PROBABILITY CALCULATION WORKSHEET HRA WORKSHEET 1 ORIGINATED BY: MC Ob / 6-3I' %

(Nuclear Safeh Group) / Date REVIEWED BY: W 7 / 5- 3/ '16

/ Date

/ /SG Rev)(wer)

REVIEWED BY: b,u / G-31-9 4 (Nucted T@ining-Operations) / Date APPROVED BY: YY M / Gf h k (NSG RM Supervisor) / D' ate '

3887 188M M888?61 P PDR

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' OPERATOR ACTION: . Operator to Stop the affected or all Circulating WatN$ystem Purnps in

10 Minutes Wrthout a Flood Watch.

BASIC EVENTI EVENT TREE: OP / SO2CW1, SO2CW3 and SO2CW4 Sa B' rrier Event Tree. -

i OPERATOR ACTION

SUMMARY

DATA SHEET I

1. INTRODUCTION This human reliability analysis (HRA) is to evaluate the human actions related to the Barrier Control Program PRA for the Safety Equipment Building in the event of a Circulating Water System failure without a floodwatch posted .

II. ACCIDENT SEQUENCES INVOLVED:

The accident sequence involved is the Circulating Water System (CWS) pipe failure resulting in flooding in the turbine building. CWS flooding in one unit will impact both units and could cause a turbine trip.

Based on transient flood calculations , in the event of a CWS flood in the turbine building, if the CWS pumps are stopped in about 10 minutes, the transient flood level rises to elevation 8'11", which is above the elevation of the bottom of barriers between the SEB and turbine building (excluding block walls).

However, even if all watertight doors between the SEB and turbine building are open, less than 5000 ft' of watu enters the SEB. This amount would not cause flooding of any non-flood qualified safety-related equipment.

Ill. DESCRIPTION OF HUMAN ACTIONS: .

The human action involved is for the operator (without the help of the floodwatch) to properly diagnose the event, identify the location of the break and stop the appropriate or all Circulating Water pumps in 10 minutes. Per the Alarm Response Instruction, SO23-15-57.C, the associated response would be to secure the affected pump (s) or isolate the source of leakage to reduce further flooding. It may be necessary to stop all four Circ Water Pumps to i terminate the flooding event.

IV. TIME LINE:

Operations has evaluated the expected response of operating crews to a flooding event initiated due to failure of a Circulating Water Pump discharge expansion bellows rupturing in the Unit 2 Turbine Building using the simulator 2

l OPERATOR ACTION: Operator to Stop the affected or a!! Circulating Water System Pumps in 10 Minutes Without a Flood Watch..

BASIC EVENTI EVENT TREE: OP / SO2CW1, SO2CW3 and SO2CW4- Barrier EventTree OPERATOR ACTION

SUMMARY

DATA SHEET (no floodwatch was included). The following were the results (reference E-mail from Van Fisher to Walter Marsh dated 9/30/93 attached):

Description of Scenario

Time to first indication (or annunciation) (T): i l

T = 0 minutes Circulating Water Pump 2MP118 Water Box Outlet !

expansion bellows ruptures. Operations selected the outlet because it makes identification of affected CWS more

difficult in the Control Room and in the field.

T(Ti)=~2 secs First alarm annunciated in the Control Room, " Turbine Building Flooding" alarm at 57C57.

T = ~3 minutes Second set of alarms annunciated in the Control Room, I Turbine Building Sump Hi/Hi level and BPS Trouble alarm.

l T = ~4.5 minutes 480 Volt ground alarms on MCC's BB. BM, BW and BK.

1 T = ~5 minutes Supply breakers to MCC's BB, BM, BW and BK open on overcurrent.

T = ~6 minutes Non-1E Instrument Bus Failure due to submergence of i 20069.

Main Generator AVR A trips due to submergence of Main Generator PT secondary circuits.

T = ~9 minutes All Instrument Air Compressors Relay will actuate due to submergence of motor intake.

T = ~9.5 minutes Main Generator Relays (Main Turbine Trip) will actuate from Stator Ground due to submergence of Main Generator PT primary circuits.

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OPERATOR ACTION: ._ Operator to Stop the affected or all Circulating Water Systerri Purnps ir.-

10 Minutes Witt;out a Flood Watch.

BASIC EVENTI EVENT TREE: OP / SO2CW1, SO2CW3 an'd SO2CV04 Barrier Event Tree OPERATOR ACTION

SUMMARY

DATA SHEET l

Field Report Script T=0 Request for inspection of turbine building to locate reason for flooding alarm.

J j T = 2 minutes Report that large amount of water at 7' as seen from the 30' elevation of the TB. Water levelis rising. Source unknown.

(if the inlet bellows had ruptured associated with south end, the field operator could report the specific water box

affected. This would have made the scenario too easy).

T = ~3 minutes Operator still on 30' passes center of condenser, vicinity of water box outlets, and reports large amounts of water

' shooting from water box outlet MOV area - cannot tell which one.

T = ~4 minutes Reports that north end is also not leaking, that the water is coming from the water box outlet area, cannot tell which one.

Conclusions

. the operators checked the Circulating Water Pump instrumentation (water box differential pressure, pump amperage, condenser vacuum) within a ,

few minutes of receipt of the flooding alarm. If an inlet bellows had ruptured, the water box DP would have dropped indicating which CW l pump to stop.

. operators requested field inspection within 30 seconds of flooding alarm receipt. It is reasonable to assume if an inlet bellows had ruptured, it would be identified by the field report within 5 minutes.

. Therefore, operators will stop the affected CW pump in less than 10 minutes.

This E-mail discussion references the outlet water box, which renders l diagnosis of which Circ Water pump to isolate more difficult. This bounds the diagnosis likelihood of an inlet water box rupture. Flood volumes from an 4

OPERATOR ACTION: Operator to Stop the affected or all Circulating Water System Pumps in .

10 Minutes Wrthout a Flood Watch.

BASIC EVENT / EVENT TREE: OP / SO2CW1, SO2CW3 and SO2CW4 Barrier Event Tree l

OPERATOR ACTION

SUMMARY

DATA SHEET outlet water box rupture are less severe than volumes from an inlet water box rupture.

Maximum allowable time (T,) :

- 10 minutes Both trains of ECCS and CCW would remain ovailable.

Post-diagnosis action time (T ) :

<1 minute To push the stop button of applicable or all Circulating Water pump (s).

Diagnosis Time (To n 7, - T - T):

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~9 minutes V. COMPETING ACTIONS:

Operator will be investigating multiple alarms annunciated in the Control Room such as the first set of alarms " Turbine Building Flooding" , the second set of alarms " Turbine Bldg. sump Hi/Hi level and BPS Trouble" alarm, 480 V MCC ground alarms, low condenser vacuum, and others that may come up. It is expected that the operator will be communicating with field report during the first 4-5 minutes of the event in diagnosing the event. If there are actions necessary such as closing an SEB barrier, it is expected that a separate operator would be sent to help due to the urgency of the event.

VI. PRECEDING RELATED ACTIONS:

None.

1 Vll. CONSEQUENCES OF FAILING TO PERFORM ACTION:

1 Failing to perform this ection in 10 minutes will result in a loss of all three CCW pumps and/or one or b :th trains of HPSI, LPSI and CS pumps if SEB barriers are breached.

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l OPERATOR ACTION: Operator to Stop the affected or all Circulating Water System Pumps in 10 Minutes Without a Flood Watch.

l BASIC EVENTI EVENT TREE: OP / SO2CW1, SO2CW3 and SO2CW4 Barrier Event Tree l

l l OPERATOR ACTION

SUMMARY

DATA SHEET l

Vill. CONSEQUENCES OF PERFORMING ACTION:

Operator action to stop the appropriate or all of the CW pump (s) in about 10 minutes will prevent submergence of the CCW pumps and/or HPSI, LPSI and CS pump (s) in the SEB.

IX. CREW TRAINING AND EXPERIENCE:

[ Provide ranking of 0 thru 5 (0 being none,1 being poor or not practiced,5 being very good)]

l SIMULATOR CLASSROOM PLANT EXPER.

IDENTIFY 5* 5* 1 DIAGNOSIS 5* 5* 1 i RESPONSE 5* 5* 1

The Alarm Response Instruction procedure is practiced regularly in the l simulator training. Degraded Circulating Water System condition is also being l practiced in the simulator training.

1 X. CLARITY OF APPLICABLE PROCEDURES:

There are procedures written that can be used related to this event: Alarm l Response Procedure SO23-15-57.C, Turbine Bldg. Flooding.

XI. AVAILABILITY OF RELEVANT INDICATIONS:

Cues For Operator Action:

l j First alarm in 2 seconds after the event - Turbine Building flooding alarm.

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OPERATOR ACTION: Operator to Stop the affected or all Circulating Water 5ystem Pumps'in 10 Minutes Without a Flood Watch.

BASIC EVENTI EVENT TREE: OP / SO2CW1, SO2CW3 and SO2CW4 Barrier Event Tree OPERATOR ACTION

SUMMARY

DATA SHEET Indicators Used:

"57C57 TURBINE BLDG FLOODING" alarm.

Upon receipt of this alarm, the required action per the ARP is to send an operator to the Turbine Building and investigate the source of this alarm. The procedure also mentioned to inspect the Main Condenser in the area of the i

Circulating Water Inlet and Outlet.

Indicator Availabilitv/Adeauaev:

The TB flooding alarm indication will provide the CR operator some verification as to the relative location of the break source. No immediate notification or response can be credited since there is no floodwatch posted in this case.

Xil. CONSIDERATIONS FOR" LOCAL" ACTIONS:

o is required action proceduralized?

Yes. SO23-15-57.C procedure states, to send an operator to the Turbine Bldg. and investigate the cause of the alarm.

o How accessible is the component from the control room? Considering distance and number of security doors, estimate time to reach component from the control room.

In ~2 minutes' , the operator will be able to report to the CR that large amount of water is present in the 7' elevation as seen from the 30' elevation.

o is action considered to be relatively simple or complex?

Relatively simple.

o Are any special tools required (keys, wrenches, etc.)? If so, will they be readily accessible during the accident sequence?

No.

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l OPERATOR ACTION: = Operator to Stop the affected or all Circulating 'thater System'PUrnps in l x10 Minutes Without a Flood Watch.

BASIC EVENTI EVENT TREE: OP ) SO2CW1, SO2CW3 and SO2CW4' Baser Event Tree.

OPERATOR ACTION

SUMMARY

DATA SHEET i

o Will performance of the action require entering a harsh environment where protection clothing or equipment is necessary?

i No.

, o Are there any unique aspects of the action which could affect the i likelihood of successful completion (i.e., requires more than one person, l must be performed concurrent with other actions, requires communication l with the control room, etc.)?

i l No.

k j Xill. COMMUNICATIONS AND OPERATOR AVAILABILITY:

Available.

, XIV. OPERATOR OVERSIGHT / CHECKING:

) It is expected that the Control Room Supervisor and the Shift Superintendent !

(SS) will be around and provide oversigh'. and second check to the NCO

! and/or NACO.

XV. STRESS LEVEL: i

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i A moderately high level of stress can be initially present in the control room due to multiple alarm annunciations.

! XVI. SPECIFIC QUESTIONS ABOUT ACTION:

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None.

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XVil. OTHER INSIGHTS:

None.

XVill.

REFERENCES:

1 Calculation M-120.15, Rev. 6, " Plant Flooding Analysis Review".

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' OPERATOR ACTION: Operator to Stop the affected or all Circulating Water System Pumps in

10 Minutes Wrthout a Flood Watch.

BASIC EVENT / EVENT TREE: OP / SO2CW1, SO2CW3 and SO2CW4 Barrier EventTree OPERATOR ACTION

SUMMARY

DATA SHEET l

2 SO23-15-57.C, Rev.1 - Annunciator Panel 57C, Vital Bus Power 3 E-mail from Van Fisher to Walter Marsh dated 9/30/93 - Operator Response to Flooding l

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POST-INITIATOR HUMAN ERROR PROBABILITY CALCULATION WORKSHEET j BASIC EVENTNAME: HUMAN ACTION DESCRIPTION: l OP-SO2CW1/SO2CW3/SO2CW4 Event Tne Operator to Stop the affected or all Circulating Water Pump (s) In 10 l minutes Without A Floodwatch l PROCEDURAL SUPPORT DETERMINATION:

STEPS 1 & 2: Is the post-initiator human action supported by written procedures? Circle yes or no below.

Xss: List Applicable Procedures: SO23-15-57.C (page 139), "AnnunciatorPanel57C, VitalBus Power" I

No: Assign Total Failure Probability (FA = 1.0.

REQUIRED TIME RELATIONSHIP DETERMINATION:

STEP 3. Determme maximum allowable time:

Maxunum Allowable Time (T.) = 10 minutes identify method of determmmg T. (Judgement., RETRAN): M-120.15. Rev. 6-Plant Floodine Analvsis Review.

STEPS 4 - 8: Determine the diagnostic time:

Post-diagnosis Action Time (T ) = 1 mirrute Identify method of determmmg T. (Judgement, walk-thm, simulator, etc): Simulator crereise. E-mail Van Fisher to WalterMarsh dated 9/30'93 "Ocerator Resoonse to Floodine" Available Diagnosis Time (TJ = T. - T, = 10 - 1 = 9 minutes Assumptions: First Alarm " Turbine Blde.. Floodine" window 57CS7 will be annunciated in 2 seconds in the control room. Durina j the next minutes several alarms such as the Turbine Blda. sumn alarm and around alarms will be anmmciated (MCC BB.BM.BW.&BK1 in CR. Alarm Resoonse Instruction ardure SO23-15-57.C " Turbine Blda.. Flooding" will direct the onerator with the reouired resoonse.

DIAGNOSIS HEP DETERMINATION:

STEP 9. 9a) Select the initial diagnosis HEP from Figure 7-1 or Table 8-2 (NUREG/CR-4772).

HEPm = 0.15 UsingMedianJointHEPFigurs 7-1(NUREGER-4772). The ARP's are being pructicedin simulator requahfication exercises.

9b) Is more than I abnormal event involved as defined in Table 8-1, Step 9b? Yer da Ifyes, adjust HEP per Step 9B (Table 8-1) and Table 8-2 & 8-4.

HEPw= 0.15 9c) Adjust HEP based on Table 8-3 guidelines: (Circle one) Upper Lower Egmnd HEPw = 0.15 9d) Is diagnosis HEP driven by symptom oriented EOl? (Circle one) Yes 62 If'yes,' adjust HEP to lower bound (Figure 7-1).

HEP % = 0.15 9e) Does HEP involve knowledge of critical RCS/ Containment parameters? (Circle one) Yes H2 If no, go to step 9g. If parameters are canunitted to memory, use lower bound values in Figure 7-1 or Table 8 2. Otherwise use nominal values. Use Table 8-3 to adjust the new values, as appropriate.

HEP %= (Circle one) Iower Nominal 10

I 9f) Not applicable.

9g) Is diagnosis ermr for HEP credible? (Circle one) Xsg No l If'yes,' write last adjusted HEP from Steps 9a - 9e as the fmal diagnosis HEP below and continue to Step

! 10. If'no,' assign ' Final Diaposis HEP' = 0.0 and discuss below.

FinalDiagnosisHEP(median) =.g]J_ (EF=10)

FinalDiaposis HEP (mean) = 0.3995274 Assumptions:

POST-DIAGNOSIS HEP DETERMINATION:

STEP 10: As dermed in Step 10 of Table 8-1, identify type of post-diaposis task and stress level:

(Circle one) Dzgamig Step-by-step I

(Circle one) Extremely high Moderately hiah i

, Based on type of task and stress level, select HEP (s) for post-diagnosis action HEP (s) from Table 8-1 [ Note: If time stress is present or if this task is required as a result of an ineffective initial task, assess applicability of doubling rule (Step 10g, Table 8-1). Ifyes, discuss in assumptions below.]

Post-Diaposis Action HEP (s)(median) = 0.05(initialerror) x 0.5(checker) = 0.025 Table 8-5. Item a4. Table 8-5. Item H 7 Post-Diaposis Action HEP (s)(mean) = 0.0665879 ;

A=wnntions: I TOTAL FAILURE PROBABILITY (Fr) D57"TRMINATION:

STEP 11: Perform step 11 of Table 8-1 using nuan values:

Fr = Final Diaposis HEP + Post-Diagnosis Action HEP (s) = 0.3995274 + 0.0665879 - E EF = 10

[ Note: If the calculated value ofF, exceeds 1.0, use 1.0.]

Note: A value of 0.5 was usedin the Event Tree.

Preparedby: Z. S. Roldan Checked By: c4.f Date: 5-$l- % Date: 3/ 'IC l

' NOTE: For all figures and tables, refer to NUREG/CR-4772. " STEPS" refer to Table 8-1 of NUREG/CR-4772.

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OPERATOR ACTION: . Operator to Stop the affected or all Circulating Water Systhm Pumps j in 10 Minutes Mth a Flood Watch BASIC EVENTl EVENT TREE: OP SO2CWS, SO2CWS & SO2CW7: Barrier' Event Tree I

i OPERATOR ACTION

SUMMARY

DATA SHEET AND POST-INITIATOR HUMAN ERROR PROBABILITY CALCULATION WORKSHEET HRA WORKSHEET 2 ORIGINATED BY: ful. t- fob / 5-31 -%

(Nuclear S&fety Group) / Date REVIEWED BY: ~r / s -3/ fr-

/ /(NSG R6 viewer) / Date REVIEWED BY: b (Nu&ar $ raining-Operations)

/ 6-JI-9 6

/ Date APPROVED BY: Yb b Abd / I hiL (NSG RM Supervisor) / bafe

OPERATOR ACTION: Operator to Stop the affecthd or all Circulating Water $ystem Pumps in

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' 10 Minutes hith a Flood Watch.

BASIC EVENTI EVENT TREE: OP / SO2CWS, SO2CW6 add SO2CW7 Barrier Event Tree OPERATOR ACTION

SUMMARY

DATA SHEET l

l

l. INTRODUCTION This human reliability analysis (HRA) is to evaluate the human actions related to the Barrier Control Program PRA for the Safety Equipment Building in the event of a Circulating Water System failure with a floodwatch posted .

II. ACCIDENT SEQUENCES INVOLVED:

The accident sequence involved is the Circulating Water System (CWS) pipe l failure resulting in flooding in the turbine building. CWS flooding in one unit ,

will impact both units and could cause a turbine trip.

Based on transient flood calculations', in the event of a CWS flood in the turbine building, if the CWS pumps are stopped in about 10 minutes, the transient flood level rises to elevation 8'11", which is above the elevation of the bottom of barriers between the SEB and turbine building (excluding block walls).

However, even if all watertight doors between the SEB and turbine building are open, lass than 5000 ft' of water enters the SEB. This amcuit would not cause flooding of any non-flood qualified safety-related equipment.

111. DESCRIPTION OF HUMAN ACTIONS: .

The human action involved is for the operator, with the help of a floodwatch, to properly diagnose the event, identify the location of the break and stop the appropriate or all Circulating Water pumps in 10 minutes. Per the Alarm Response Procedure, SO23-15-57.C, the associated response would be to secure the affected pump (s) or isolate the source of leakage to reduce further flooding. It may be necessary to stop all four Circ Water Pumps to terminate the flooding event.

IV. TIME LINE:

Operations has evaluated the expected response of operating crews to a flooding event initiated due to failure of a Circulating Water Pump discharge expansion bellows rupturing in the Unit 2 Turbine Building using the simulator 2

4 OPERATOR ACTION: f operator to Stop Uie affected or all Circulating Waterdystem Pumpe 4

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L10 Minutes 36(.@ a Flood Watch.'

1 i BASIC EVENT / EVENT TREEi OP / SO2CWS, SO2CW6 and SO2CW7: Barrier Event Tree 3 OPERATOR ACTION

SUMMARY

DATA SHEET j (no floodwatch was included). The following were the results (reference E-mail from Van Fisher to Walter Marsh dated 9/30/93:

$ Description of Scenario i

l Time to first indication (or annunciation) (T): i I

i T = 0 minutes Circulating Water Pump 2MP118 Water Box Outlet expansion bellows ruptures. (Operations selected the outlet because it makes identification of affected CWS more

difficult in the Control Room and in the field). At this point

! the floodwatch is expected to immediately notify the j control room of the event, describing the flood and the approximate location of the water source.

j T(Ti)=~2 secs First alarm annunciated in the Control Room, Turbine Building Flooding Alarm.

} T = ~3 minutes Second set of alarms annunciated in the Control Room, Turbine Building Sump Hi/Hi level and Blowdown

Processing System (BPS) Trouble alarm.

T = ~4.5 minutes 480 Volt ground alarms on MCC's BB. BM, BW and BK T = ~5 minutes Supply breakers to MCC's BB, BM, BW and BK open on overcurrent.

1 T = ~6 minutes Non-1E Instrument Bus Failure due to submergence of 20069.

Main Generator AVR A trips due to submergence of Main Generator PT secondary circuits.

T = ~9 minutes All Instrument Air Compressors relay will actuate due to submergence of motor intake.

T = ~9.5 minutes Main Generator Relays (Main Turbine Trip) will actuate from Stator Ground due to submergence of Main Generator PT primary circuits.

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OPERATOR ACTION: ' Operator to Stop the affected or all. Circulating Water System Pumps in

' 10 Minutes' Y{dh a Flood Watch.

BASIC EVENTI EVENT TREE: OP / SO2CWS, SO2CW6 and SO2CW7' Bahier Event Tree OPERATOR ACTION

SUMMARY

DATA SHEET 1

l Field Report Script i

T=0 Request for inspection of turbine building to locate reason for I flooding alarm. At this point the floodwatch is expected to I immediately notify the control room of the event, describing ,

the flood and the approximate location of the water source. I T = 2 minutes Report that large amount of water at 7' as can be seen from the 30' elevation of the TB. Water level is rising. Source unknown. (if the inlet bellows had ruptured associated with south end, the field operator could report the specific water box affected. This would have made the scenario too easy).

T = ~3 minutes Operator still on 30' passes center of condenser, vicinity of l water box outlets, and reports large amounts of water shooting from water box outlet MOV area - cannot tell which one.

. T = ~4 minutes Reports that north end is also not leaking, that the water is coming from the water bux outlet area, cannot tell which one.

{ Conclusions

. the operators checked the Circulating Water Pump instrumentation (water box differential pressure, pump amperage, condenser vacuum) within a i few minutes of receipt of the flooding alarm. If an inlet bellows had i ruptured, the water box DP would have dropped indicating which CW pump to stop.

. operators requested field inspection within 30 seconds of flooding alarm receipt. It is reasonable to assume if an inlet bellows had ruptured, it would be identified by the field report within 5 minutes. A floodwatch would report the rupture in <1 minute.

. Therefore, operators will stop the affected CW pump in less than 10 minutes.

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, OPERATOR ACTION: Operator to Stop the affected or all Circulating Water System Pumps in 1

10 Minutes With a Flood Watch.

BASIC EVENTI EVENT TREE: OP / SO2CW5, SO2CW6 and SO2CW7 Barrier Event Tree OPERATOR ACTION

SUMMARY

DATA SHEET This E-mail discussion references the ou'.!ct water box, which renders diagnosis of which Circ Water pump to isolate more difficult. This bounds the j diagnosis likelihood of an inlet water box rupture. Flood volumes from an outlet water box rupture are less severe than volumes from an inlet water box rupture.

Maximum allowable time (T ):

- 10 minutes Both trains of ECCS & CCW would remain available.

Post-diagnosis action time (T,) :

<1 minute To push the stop button of applicable or all Circulating Water pump (s).

Diagnosis Time (To = T , - T, - T)i : I

~9 minutes V. COMPETING ACTIONS: l Operator will be investigating multiple alarms annunciated in the Control Room !

such as the first set of alarm " Turbine Building Flooding" , the second set of I alarms " Turbine Bldg. sump Hi/Hi level and BPS Trouble" alarm, 480 V MCC l ground alarms, low condenser vacuum, and others that may come up.

VI. PRECEDING RELATED ACTIONS:

None. i Vll. CONSEQUENCES OF FAILING TO PERFORM ACTION:

Failing to perform this action in about 10 minutes will result in a loss of all three CCW pumps and/or one or both trains of HPSI and LPSI pumps if SEB barriers are breached.

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l OPERATOR ACTION: Operator to Stop the affected or all Circulating Water System Pumps in -

10 Minutes y{ith a Flood Watch.

BASIC EVENTI EVENT TREE: OP / SO2CWS, SO2CW6 and SO2CW7 Barrier Event Tree l OPERATOR ACTION

SUMMARY

DATA SHEET Vill. CONSEQUENCES OF PERFORMING ACTION:

I Operator action to stop the appropriate or all of the CW pump (s) in about 10 minutes will prevent submergence of the CCW pumps and/or HPSI and LPSI pump (s) in the SEB.

IX. CREW TRAINING AND EXPERIENCE:

i (Provide ranking of 0 thru 5 (0 being none,1 being poor or not practiced,5 l being very good)]

m SIMULATOR CLASSROOM PLANT EXPER.

IDENTIFY 5* 5* 1 DIAGNOSIS 5* 5* 1 RESPONSE 5* 5* 1

The Alarm Response Instruction procedure is practiced regularly in the j simulator training. Degraded Circulating Water System condition is also being ,

l practiced in the simulator tralning. l l

l X. CLARITY OF APPLICABLE PROCEDURES:

l l

l There are procedures written that can be used related to this event: Alarm l Response Procedure SO23-15-57.C, Turbine Bldg. Flooding.

l XI. AVAILABILITY OF RELEVANT INDICATIONS:

Cues For Operator Action:

. First alarm in 2 seconds after the event - Turbine Building flooding alarm.

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l OPERATOR ACTION: (Operator to Stop the affected or ali Circulating' Water $yst5m Pumps in

.10 Minutes Y{!!b a Flood Watch.

BASIC EVENTI EVENT TREE: OP / SO2CWS, SO2CW6 and SO2CW7. Barrisr Event Tree!

OPERATOR ACTION

SUMMARY

DATA SHEET l Indicators Used:

l "57C57 TURBINE BLDG FLOODING" alarm.

Upon receipt of this alarm, the required action per the ARP is to send an operator to the 7' Turbine Building and investigate the source of this alarm. It is expected that the CRS will . send help to the operators in the field as necessary.

The procedure also mentioned to inspect the Main Condenser in the area of the Circulating Water Inlet and Outlet.

l Indicator Availabilitv/Adeauacy-l The TB flooding alarm indication plus the floodwatch, will provide th:> CR i operator some verifl cation as to the relative location of the break source (i.e.

l which Unit) and description of the volume of this flood.

l

! Xil. CONSIDERATIONS FOR" LOCAL" ACTIONS:

l l o Is required action proceduralized?

l Yes. SO23-15-57.c procedure states, to send an operator to the 7' Turbine Bldg. and investigate the cause of the alarm.

1 o How accessible is the component from the control room? Considering distance and number of security doors, estimate time to reach component from the control room.

l The floodwatch will report large amount of water in <1 minute.

o is action considered to be relatively simple or complex 7 l Relatively simple.

o Are any special tools required (keys, wrenches, etc.)? If so, will they be readily accessible during the accident sequence?

1 None.

o Will performance of the action require entering a harsh environment 7

aw#, m- 5 42.4 _. 5 & .2 . -4 _ -A-.4 a--- c-i -

A . -e--+-+ m& A _w.- : __-

l j OPERATOR ACTION: Operator to Stop the~ affected or all Circulating Waterdystem Pumps in -

110 Minutes Ejth a Flood Watch.

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BASIC EVENTI EVENT TREE: OP / SO2CW5', SO2CW6 and SO2CW7 Barrier Eve'nt Tree l

l OPERATOR ACTION

SUMMARY

DATA SHEET where protection clothing or equipment is necessary?

No.

o Are there any unique aspects of the action which could affect the likelihood of successful completion (i.e., requires more than one person, .

must be performed concurrent with other actions, requires communication with the control room, etc.)? ;

1 No.

l Xill. COMMUNICATIONS AND OPERATOR AVAILABILITY: l Normal means of communications should be available.

XIV. OPERATOR OVERSIGHT / CHECKING:

It is expected that the Control Room Supervisor and the Shift Superintendent (SS) will be around and provide oversight and second check to the NCO and/or NACO.

XV. STRESS LEVEL:

i A moderately high stress level is expected.

XVI. SPECIFIC QUESTIONS ABOUT ACTION:

None.

XVil. OTHER INSIGHTS:

None.

XVill.

REFERENCES:

1 Calculation M-120.15, Rev. 6, " Plant Flooding Analysis Review".

2 SO23-15-57.C, Rev.1 - Annunciator Panel 57C, Vital Bus Power 8

l OPERATOR ACTION: Operator td Stop the affected or all Circulating Watek5ystem Pumps in

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j 310 Minutes Fjh a Flood Watch.

) - BASIC EVENT / EVENT TREE: OP / SO2CWS, SO2CW6 arid SO2CW7. Banier Event Tree

! OPERATOR ACTION

SUMMARY

DATA SHEET i

3 E-mail from Van Fisher to Walter Marsh dated 9/30/93 - Operator j Response to Flooding i

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9

l POST-INITIATOR HUMAN ERROR PRO 7AILITY CALCULATION WORKSHEET BASIC EVENT NAME: HUMAN ACTION DESCRIPTION:

OP-SO2CW5/SO2CW6/SO2CW* Event Tne Operator to Stop the affected or all Circuladng Water Pump (s) in 10 Minutes Woth A Flood Watch PROCEDURAL SUPPORT DETERMINATION:

STEPS 1 & 2: Is the post-initiator human action supported by written procedures? Circle yes or no below.

Xsg: List Applicable Procedmw SO23-15-57.C (page 139), "AnnunciatorPanel57C, VitalBus Power" No: Assign Total Failure Probability (F.r) = 1.0.

REQUIRED TIME RELATIONSHIP DETERMINATION:

STEP 3. Determme maxunum allowable time:

Maximum Allowable Time (T ) = 10 minutet Identify method of deternumng T. (Judgement., REIRAN): M-12015. Rev. 6-Plant Floodine Analysis Review.

STEPS 4 - 8: Determme the diagnostic time:

Post-diagnosis Action Time (T ) = 1 minute Identify method of % mining T (Jndganant. walk-thru, simulator, etc): Simulator exercise- E-mail Van Fisher La WalterMarsh dated 98083 "OceratorResoonse to Floodine" Available Diagnosis Time (TJ = T. - T, = 10 9 minutes Assumptions: It is exnected that at T=0. the floodwatch would notify the CR of the event. First Alarm " Turbine Blde. Flooding" window 57CS7 will be annunciat~I in 2 ==la in the control room. During the next mimite several alarms such as the Turbine Blda. sumn alarm and around aintms will be anmmeiat~i(MCC BB.BM.BW.& BIG in CR. Alarm Response Instraction inMmc

.SO23-15-57.C " Turbine Blde_ Flooding" will direct the operator to do the reauinA resoonse CIAGbOSIS HEP DETERMINATION:

SRSL 9a) Select the initial diagnosis HEP fror- Figure 7-1 or Table 8-2 (NURE0/CR-4772).

HEPa = 0.15 UsingMedianJo,ntHEPFigurs 7-1(NUREGCR-4772). The use ofARP's an being stnssedin simulator nquahfication exercises.

9b) Is more than 1 abnormal event involved as defined in Table 8-1, Step 9b? Yes Eg Ifyes, adjust HEP per Step 9B (Table 8-1) and Table 8-2 & 8-4.

1 HEP.a,,,,,= 0.15 (EF=10) 9c) Adjust HEP based on Table 8-3 guidelines: (Circle one) Upper Lmy.cr Nominal HEPw = 0.015 (Because ofthefloodwatch, the eventis nportedimmediately to the CR.)

9d) Is diagnosis HEP driven by symptom oriented EOI? (Circle one) Yes Eg If'yes,' adjust HEP to lower bound (Figure 7-1).

HEP % = 0.015 9e) Does HEP involve knowledge of critical RCS/Cnntainment parameters? (Circle one) Yes Eg if no, go to step 9g. Ifparameters are committed to memory, use lower bound values in Figure 7-1 or Table 8-2. Othenvise use nominal values. Use Table 8-3 to adjust the new values, as appropriate.

HEP %= (Circle one) Imer Nominal 10

d 4

9f) Not applicable.

$ 9g) Is disposis error for HEP credibic? (Circle one) Ya No If'yes,' write last adjusted HEP from Steps 9a - 9e as the final diagnosis HEP below and continue to Step

10. If'no,' assip Tinal Diagnosis HEP' = 0.0 and discuss below.

FinalDiagnosisHEP(median) = 0.015 4

FinalDiaposis HEP (mean) = 0.04 (EF-10)

Assumptions: The ffoodwatch willomvide eenemilocation ofthe break source and feedback such as which Unit is afrected.

- POST-DIAGNOSIS HEP DETERMINATION:

i STEP 10: As defined in Step 10 of Table 84, identify type of post-diaposis task and stress level:

' DBagdg Step-by-step (Circle one)

Extremely high Moderately hieh (Circle one)

Based on type of task and stress level, select HEP (s) for post-diagnosis action HEP (s) from Table 8-1. [ Note: If time stress is present or if this task is required as a result of an ineffective initial task, assess applicability of

]

doubling rule (Step 10g, Table 8-1). Ifyes, discuss in assumptions below.)

Post-Disposis Action HEP (s)(median) = 0.05(initialenvr) x 0.05(checker) = 0.0025 Table 8-5. Item H4. Table 8-5. Item # 9 1

Post-Diagnosis Action HEP (s)(mean) = 0.00665879 Assumptions: The flood watch will orovide nositive identification of the event and feedback.

] TOTAL FAILURE PROBABILITY (Fr) DETERMINATION:

! STEP 11: Perform step 11 of Table 8-1 using Huan values:

F,= Final Diagnosis HEP + Post-Diaposis Action HEP (s) = 0.04 + 0.00665879 ,&fff_ EF = 10

[ Note: If the calculated value of F, exceeds 1.0, use 1.0.]

Note: A value of 0.05 was used Prepared by: Z. S. Roldan CheckedBy: 24 m Date: 5/31/96 Date:

/E-3/-W

/

NOTE: For all figures and tables, refer to NUREG/CR-4772. ' STEPS" refer te Table 8-1 of NUREG/CR-4772.

11

OPERATOR ACTION: Operator to Alidn Charging Pumps to the RCS in 2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months givan 1

- loss of SDC caused by flooding or steam line break.?

. BASIC EVENT /EVENTTREE: OP/SO2CC7,SDRCCS; OP1/SO2CW3,'SO2CW6; OP2/SO2CC5 All/SO2SL3; D/SO2FR2; E/SO2SL5; G/SO2CC9 : Barrier Event

, -Troei OPERATOR ACTION

SUMMARY

DATA SHEET I l

AND POST-INITIATOR HUMAN ERROR PROBABILITY l

CALCULATION WORKSHEET HRA WORKSHEET 3 ORIGINATED BY: MIAb / 5 9 6 :

(Nuclear Safety Group) / Date REVIEWED BY: / 5-3/- 7 6

/ Date

[ (WSG Rev)fwer)

REVIEWED BY: b / 6 31-9h (Nucler T($1ning-Operations) / Date APPROVED BY: NL b- -

/ 6f/X 9 (

(NSG RM Supervisor) / D' ate' l

I l

l monum OPERATOR ACTION: Operator to Align Charging Pumps to the RCS in 2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months given loss of SDC caused by flooding or steam line break . j BASIC EVENT / EVENT TREE: OP/SO2CC7,SDRCC5; OP1/SO2CW3,SO2CW6; OP2/SO2CC5 All/SO2SL3;D/SO2FR2;E/SO2SL5;G/SO2CC9 Barrier EventTree l

l. INTRODUCTION:

This human reliability analysis (HRA) is to evaluate the human actions related to the Barrier Control Program PRA for the Safety Equipment Building. !

II. ACCIDENT SEQUENCES INVOLVED:

The accident sequence pertains to an event resulting in a failure of Shutdown Cooling System (SDCS) in the Safety Equipment Building (SEB) and the only source of inventory make-up to prevent core uncovery are the Charging Pumps during Modes 4,5 and 6(level <23'). Mid-loop condition (which is the most j restrictive) is assumed in this case. Time-to-core uncovery is ~2.5 hour5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months s2 .s n j the event of a loss of SDC while at mid-loop.

Failure of the SDCS can be caused by flooding or auxiliary steam line break.

The flooding event can be due to Circulating Water System (CWS) pipe break, j Component Cooling Water (CCW) pipe break, Saltwater Cooling (SWC) pipe break or Fire Suppression pipe break. The steam line break is due to auxiliary steam line break at the corridor of the 8' SEB. If the barriers are impaired during any of these events, the hazard (flood or steam) will travel or propagate into the SEB which can cause failure of CCW pumps or LPSI, HPSI, CS pumps.

Ill. DESCRIPTION OF HUMAN ACTIONS:

The human action involved is to inject water to the RCS using the Charging Pumps2 within 2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months . This is accomplished by aligning two manual valves and one of two motor operated valve (MOV) at CR57 to the RCS and starting the Charging Pumps at CR58. The Loss of SDC procedure S023-13-15 Att. 5, Section 2.4, describes the actions required.

l l Charging Pumps can be started at CR58:

2(3) HS-9228-1, P190 2(3) HS-9229-1(2), P191

2(3) HS-9230-2, P192 Any one of the MOV's can be opened at CR57

2(3)HV9420 2(3)HV9434 2

i i

i l

OPERATOR ACTION: Operator to Align Charging Pumps to the RCS in 2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months given loss of SDC caused by flooding or steam line break .

BASIC EVENT / EVENT TREE: OP/SO2CC7,SDRCC5; OP1/SO2CW3,SO2CW6; OP2/SO2CC5

' All/SO2SL3;D/SO2FR2;E/SO2SL5;G/SO2CC9 Barrier EventTree 1

Manual valves:

S2(3)1208MUO65 Unit 2 - Room 106A, Unit 3 - Room 107J in Radwaste Area S2(3)1204MU154 Room 209, Penetration Area Elev. 30, near Penetration 71 S2(3)1208MU005 Room 209, Penetration Area Elev. 30, near Penetration 49 l

Note: Per S023-13-15 Att. 5 Section 2.4.7 or 2.4.8, MUO65 will be opened together with either MU154 or MU005 (HPSI Header 1 or 2, respectively).

IV. TIME LINE:

Time to first indication (or annunciation) (T): i Approximately 5 minutes after a pipe break (e.g. CCW, Circ Water pipe break),

an alarm will be annunciated in the CR57, "SEB Train A or B Flooding" at 57C46 or 57C56.

t if the SDCS fails (such as the LPSI pumps and/or the associated CCW pumps) due to a steam line break, several alarms will be annunciated in CR57C and CR64A.

The alarms and indications listed below will help the operator diagnose the loss of SDC:

Reactor Core exit temperature is indicated on QSPDS Page 633 for CETs and Page 721 for HJTCs.

e RWLP thermocouple reference temperature is a measure of RX Core l temperature just above the Upper Fuel Alignment Plate. 1 l e CR57 2(3)TI-0303-1,2(3)Tl-0303-2,2(3)TR-0351 A - SDCS Temperature e 57C39 "SDCS FLOW LO" e LPSI/CS Motor Amperage Fluctuating 1

For SEB flooding, the following alarms will annunciate in the CR:

e 57C46 " SAFETY EQPT BLOG TRAIN A FLOODING" e 57C56 " SAFETY EQPT BLDG TRAIN B FLOODING" 3

l J

OPERATOR ACTION: Operator to Align Charging Pumps to the RCS in 2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months given loss of SDC caused by flooding or steam line break . .

BASIC EVENT / EVENT TREE: OP/SO2CC7,SDRCC5; OP1/SO2CW3,SO2CW6; OP2/SO2CC5 All/SO2SL3; D/SO2FR2; E/SO2SL5; G/SO2CC9 Barrier Event Tree '

If CCW fails, the following alarms will annunciate in the CR57:

64A37 " SHUTDOWN HX TRAIN A CCW FLOW LO"

64A38 " SHUTDOWN HX TRAIN B CCW FLOW LO" ,

64A39 "CCW PUMP MOTOR BRG TEMP HI" Maximum allowable time (T ): l l

2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months Post-diagnosis action time (T ) :

25 minutes (includes field alignment of Charging pumps, if necessary) l Diagnosis Time (To = T , - T. - T)i : ,

T = T , - T, - T =i 2.5 hrs - 25 min - 5 min = 2 hrs !

V. COMPETING ACTIONS:

Isolation of the initiating event, such as; CCW line break, CWS pipe break, or ;

steam line break. !

l VI. PRECEDING RELATED ACTIONS:

None. )

Vll. CONSEQUENCES OF FAILING TO PERFORM ACTION:

1 Failing to perform this action within 2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months will eventually lead to core uncovery.

Vill. CONSEQUENCES OF PERFORMING ACTION:

Operator action to inject water to RCS within 2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months will prevent core uncovery.

IX. CREW TRAINING AND EXPERIENCE:

[ Provide ranking of 0 thru 5 (0 being none,1 being poor or not practiced,5 being very good))

4

OPERATOR ACTION: Operator to Align Charging Pumps to the RCS in 2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months given loss of SDC caused by flooding or steam line break . j i BASIC EVENT / EVENT TREE: OP/SO2CC7,SDRCC5; OP1/SO2CW3,SO2CW6; OP2/SO2CC5 - l All/SO2SL3; D/SO2FR2; E/SO2SL5; G/SO2CC9 Barrier Event Tree i

SIMULATOR CLASSROOM PLANT EXPER.

IDENTIFY 5* 5* 1 DIAGNOSIS 5* 5* 1 RESPONSE 5* 5* 1

The Alarm Response Instruction procedure is practiced regularly in the simulator training.

X. CLARITY OF APPLICABLE PROCEDURES:

SO23-13-15 Loss of Shutdown Cooling System is reasonably clear procedure.

XI. AVA.lLABILITY OF RELEVANT INDICATIONS All relevant indications are available such as SDC pump flow, LPSI pump amperage, etc..

Xil. CONSIDERATIONS FOR" LOCAL" ACTIONS:

o is required action proceduralized?

Yes. SO23-15-57.C procedure states, to dispatch an operator to the affected area and investigate. The Loss of SDC procedure (SO23-13-15) specifies actions necessary in aligning the Charging Pumps for injection including the manual valves.

o How accessible is the component from the control room? Considering distance and number of security doors, estimate time to reach component from the control room.

In ~25 minutes the operator would be able to align the charging pumps per S023-13-15. This includes travel time to reach the valve location and manipulate the valves (2" line).

o is action considered to be relatively simple or complex 7 5

OPERATOR ACTION: Operator to Align Charging Pumps to the RCS in 2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months given loss of SDC caused by flooding or steam line break .

BASIC EVENT / EVENT TREE: OP/SO2CC7,SORCC5; OP1/SO2CW3,SO2CW6; OP2/SO2CC5

~ All/SO2SL3;D/SO2FR2;E/SO2SL5;G/SO2CC9 Barrier EventTree Relatively simple.

o Are any special tools required (keys, wrenches, etc.)? If so, will they be readily accessible during the accident sequence?

None.

l o Will performance of the action require entering a harsh environment l where protection clothing or equipment is necessary? ,

1 No.

o Are there any unique aspects of the action which could affect the likelihood of successful completion (i.e., requires more than one person, must be performed concurrent with other actions, requires communication with the control room, etc.)?

No.

Xill. COMMUNICATIONS AND OPERATOR AVAILABILITY: l l

All normal means of communications are expected to be available.

XIV. OPERATOR OVERSIGHT / CHECKING:

It is expected that the Control Room Supervisor and the Shift Superintendent (SS) will be around and provide oversight and second check to the NCO and/or NACO.

XV. STRESS LEVEL:

Moderately high stress level is expected.

XVI. SPECIFIC QUESTIONS ABOUT ACTION:

None.

6

OPERATOR ACTION: Operator to Align Charging Pumps to thz RCS in 2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months gNen loss of l SDC caused by flooding or steam line break .

BASIC EVENT / EVENT Tr<EE: OP/SO2CC7,SORCC5; OP1/SO2CW3,SO2CW6; OP2/SO2CC5 '

All/SO2SL3; D/SO2FR2; E/SO2SL5; G/SO2CC9 Barrier Event Tree l

4 l

i I

1 XVil. OTHER INSIGHTS:

None.

XVill.

REFERENCES:

1 SO23-15-57.C, Rev.1 - Annunciator Panel 57C, Vital Bus Power l 2 SO23-13-15, Rev. 3 - Loss of Shutdown Cooling, AOI !

3 SO23-15-61.A, Rev.1 - Annunciator Panel 61 A, Firewater / Rad Monitors 4 P&lD 40112C 5 Calculation N-0220-029, Rev. O, dated May 1993 RCS Heatup Following Loss of SDC.

l 7

POST-INITIATOR HUMAN ERROR PROBABILITY CALCULATION WORKSHEET BASIC EVENT NAME: HUMAN ACTION DESCRIPTION:

OP-SO2CC7/SDRCCJ; OP1-SO2CWJ/SO2CW6 Operator to Align Charging Pumps to the RCS in 2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months OP2-SO2CC5 ; ALI-SOSL3; D-SO2FR2 Given less of SDC caused by Flooding or Steam Line Break E-SOSLS: G-SO2CC9 PROCEDURAL SUPPORT DETERMINATION:

STEPS 1 & 2: Is the post-initiator human action supported by written procedures? Circle yes or no below.

Y_es:

e List Applicable Procedures: SO23-15-57.C, "AnnunciatorPanel57C, VitalBus Power"; SO2-13-15-Loss of SDC. )

l No: Assign Total Failure Probability (F,) = 1.0. I REQUIRED TIME RELATIONSHIP DETERMINATION: l STEP 3. Determine maximum allowable time:

Maximum Allowable Time (T,) = 2.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months identify method of determmmg T (Judgement,, RETRAN): SO23-I3-15 Loss o/SDC: Calcidation # AI-120-15 STEPS 4 - 8: Determine the diagnostic time:

Post-diagnosis Action Time (T,) = 30 minutes Identify method of determmmg T, (Judgement, walk-thru, simulator, etc): Judeement. simulator and ver vrocedures SO23-13-15. SO23-15-57.C & SO23-15-64.A.

Available Diagnosis Time (TJ = T, - T, = 2.5 hrs - 30 mins = 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months Assumptions:. l DIAGNOSIS HEP DETERMINATION: (start here) l l STEP 9. Select the initial diagnosis HEP from Figure 7-1 or Table 8-2 (NUREG/CR-4772)..

9a) l HEP,,,a = 6E-5 Using Afedian JointHEP Figure 7-1(NUREGCR-4772). The use ofARP's & AOl's are being stressed in simulator requahpcatlan exercises.

9b) Is more than I abnormal event involved aa defined in Table 8-1, Step 9b7 Yes d2 j If yes, adjust HEP per Step 9B (Table 8-1) and Table 8-2 & 8-4.

HEPg .,a= 6E-5 9c) Adjust HEP based on Table 8-3 guidelines: (Circle one) Upper Lower 890lLnd HEP ,,a = 6E-5 9d) Is diagnosis HEP driven by symptom oriented EOl? (Circle one) Yes Ng l If'yes,' adjust HEP to lower bound (Figure 7-1).

l HEP4 ,,,a = 6E-5 9e) Does HEP involve knowledge of critical RCS/ Containment parameters? (Circle one) Yes Ng If no, go to step 9g. If parameters are committed to memory, use lower bound values in Figure 7-1 or Table 8-2 Otherwise use nominal values. Use Table 8-3 to adjust the new values, as appropriate.

HEP4 ,,,a =

(Circle one) Iower Nominal 4

8

4 4

4

9f) Not applicable.

9)8 Is diagnosis error for HEP credible 7 (Circle one) Yes 52 If'yes,' write last adjusted HEP from Steps 9a - 9e as the final diagnosis HEP below and contmue to Step i

10. If'no,' assign Tinal Diagnosis HEP' = 0.0 and discuss below. l l

4 Final Diagnosis HEP (median) =,1Q.

FinalDiagnosis HEP (mean) =,10. I Assumptions: Diarnosis ermr is comidered not cndible because ofnumemus indications such Roodine alarm in the MR SDC ouma low Row. SDC oumo amoemee Ructuatine. These indications willdinct the onemtor to utilize 5023-13-15. LOSS *0FSDC.

POST-DIAGNOSIS HEP DETERMINATION:

STEP 10: As defined in Step 10 of Table 8-1, identify type ofpost-diagnosis task and stress level:

1 (Circle one) Dynamic gggdggga (Circle one) Extremelyhigh Madaratalv hiah Based on type of task and stress level, select HEP (s) for post-diagnosis action HEP (s) from Table 8-1. [ Note: If time stress is present or if this task is required as a result of an ineffective initial task, assess applicability of doubling rule (Step 10g, Table 8-1). Ifyes, discuss in assumptions below.]

Post-Diagnosns Action HEP (s)(mminan) = IE-3(L="! ermr} x 0.2(checker) = 2E-4 Table 8-5. Items #10 &6.

Post-Diagnosis Action HEP (s)(mean) = SE-4 A-=>=ations: Post-Di==nnain winn of 0.2 is allowed W== of ti== availahle (2hrst TOTAL FAILURE PROBABILITY (Fr) DETERMINATION:

STEP 11: Perform step 11 of Table 8-1 using maan values:

Fr = Final Diagnoms HEP + Post-Diagnoms Action HEP (s) = 0.0 + JE-4 = ,Jfag. EF = 10 (Note: If the calculated value ofFrexceeds 1.0, use 1.0.]

Note: A value of IE-3 was chosen andwas usedin the appkoMe E .nt Tnes. .

Prepared by: Z. S. Roldan CwkulBy: [/h ,

Date:

//

S -J/ -u f

Date: 5 9-%

NOTE: For all figures and tables, refer to NUREG/CR-4772.

STEPS" refer to Table 8-1 of NUREG/CR-4772.

l l

9

I OPERATOR ACTION: Operator to Align SFP Cooling to the RCS within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months given loss of SDC. .

BASIC EVENT / EVENT TREE: ' OP/SO2SL4,SO2SLS,SO2CC6,SO2C10,SO2FR3:

OP1/SO2CW7,SO2CW4;OP2/SO2CC4;C/SO2FR6 Barrier Event Tree OPERATOR ACTION

SUMMARY

DATA SHEET AND POST-INITIATOR HUMAN ERROR PROBABILITY CALCULATION WORKSHEET HRA WORKSHEET 4 ORIGINATED BY: Db '

h / F- 3 / - 76 (Nuclear Safdty Group) / Date REVIEWED BY: A N" a / 4 -/P-P.6

/ jdSG Revfewer) / Date REVIEWED BY: b W Crth <wrod M cof 7-3/-46

'(Nuclear Trainirig-Oper$tions) / Date APPROVED BY: W' Tkh / 6[ISN L, (NSG RM Supervisor) I datd i

l

i OPERATOR ACTION: Operator to Align SFP Cooling to the RCS within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months given loss of SDC.

t i BASIC EVENT / EVENT TREC: OP/SO2SL4,SO2SL6,SO2CC6,SO2C10,SO2FR3:

OP1/SO2CW7,SO2CW4;OP2/SO2CC4;C/SO2FR6 Barrier Event Tree OPERATOR ACTION

SUMMARY

DATA SHEET a

l. INTRODUCTION

This human reliability analysis (HRA) is to evaluate the human actions related to the Barrier Control Program PRA for the Safety Equipment Building while the affected Unit (2 or 3) is in Mode 6 and the RCS water level is >23'.

II. ACCIDENT SEQUENCES INVOLVED:

The accident sequence per'ains to an event resulting in failure of Shutdown Cooling System (SDC), High Pressure Safety injection (HPSI), Containment Spray (CS) and Component Cooling Water (CCW) pumps in the Safety Equipment Building (SEB) while the affected Unit is in Mode 6 with the RCS water level >23'.

Failure of the SDCS can be caused by flooding or auxiliary steam line break in the SEB corridor. The flooding event can be due to Circulating Water System (CWS) breaks, Component Cooling Water (CCW) pipe break or Fire Suppression pipe break in the SEB.

The most limiting case is when the fuel is in the core prior to core offload. The only alternate method of core cooling during this configuration is to align Spent Fuel Pool Cooling5 8 to the RCS. Time to boiling in the refueling cavity during this configuration (about 10 days after shutdown) is about 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ' in the event of a loss of core cooling.

The total time available to the operator to diagnose and take action to align SFP pump suction to the RCS was conservatively assumed to be the time to bulk boiling in the refueling pool (i.e.,12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ). However, since the end state is core damage (core uncovery), the actual time available to the operator is greater than 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . Once this alignment is performed, the RCS and the SFP inventories circulate, the time to boiling increases to about 28 hours3.240741e-4 days 0.00778 hours 4.62963e-5 weeks 1.0654e-5 months even if CCW is not available.

Ill. DESCRIPTION OF HUMAN ACTIONS:

The CR operator will refer to AOI SO23-13-15(Loss of SDC) during the Loss of 2

i I

OPERATOR ACTION: Operator to Align SFP Cooling to the RCS within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months given loss of SDC. ,

1 BASIC EVENT / EVENT TREE: OP/SO2SL4,SO2SL6,SO2CC6,SO2C10,SO2FR3; OP1/SO2CW7,SO2CW4;OP2/SO2CC4;C/SO2FR6 Barrier Event Tree OPERATOR ACTION

SUMMARY

DATA SHEET SDC event and will be directed to do 01 SO23-3-2.6.1(CS/SDC/SFP Cooling Crosstie Operation) in aligning SFP Cooling to Recirculate the RCS. The following human actions are necessary to provide an alternate cooling to the RCS:

a) Align Spent Fuel Pool Cooling to recirculate the RCS per 01 SO23-3-2.6.1 Attachments 15 & 16. Based on interviews with the operations personnel, the estimated time for this action was 3 to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months . This time was conservatively doubled to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months to include a checker. Time is also available for a second independent checker if the initial action failed.

b) Align the SFP heat exchangers from the opposite Unit CCW. This action would be required if CCW failed, and can be accomplished by using SO23-13-23 Attachment 2 or 3. This action follows item a) above, and as stated in Section ll, it may be completed within 28 hours3.240741e-4 days 0.00778 hours 4.62963e-5 weeks 1.0654e-5 months . Operator failure probability to complete this action was judged to be negligible because four critical valve alignments are required to cross tie CCW to the opposite unit and 28 hours3.240741e-4 days 0.00778 hours 4.62963e-5 weeks 1.0654e-5 months is available to perform these alignments.

To place the SFP pumps in the RCS recirculate mode, four critical valve alignments are required: !

1) open 1201MUO33 located in Penetration 9' elevation Rm 111 '

2) open 1219MUO13 located in Radwaste Bldg 37' elevation Rm 305E

3) close 1219MUO12 located in Fuel Handling Bldg elevation 63' Rm 411

4) open 1201MU994 located in Penetration 9' elevation Rm 111 If CCW also failed, to cross tie to the other unit's CCW system, four more critical valve alignments (within 28 hours3.240741e-4 days 0.00778 hours 4.62963e-5 weeks 1.0654e-5 months ) would be required:

5) open HV-6217 located in Radwaste Bldg elevation 50' Room 404A

6) open HV-6465 located in Radwaste Bldg elevation 50' Room 404A

7) open 1203MU100 located in Radwaste Bldg elevation 50' Room 406A

8) open 1203MU002 located in Radwaste Bldg elevation 50' Room 406A IV. TIME LINE:

Time to first indication (or annunciation) (T): i 3

OPERATOR ACTION: Operator to Align SFP Cooling to the RCS within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months given loss of SDC.

BASIC EVENTIEVENT TREE: . OP/SO2SL4,SO2SL6,SO2CC6,SO2C10,SO2FR3; OP1/SO2CW7,SO2CW4;OP2/SO2CC4;C/SO2FR6 Barrier Event Tree OPERATOR ACTION

SUMMARY

DATA SHEET Approximately 5 minutes (0.08 hrs) after a pipe break (e.g. CCW, Circ Water pipe break), an alarm will be annunciated in the CR57, "SEB Train A or B Flooding" at 57C46 or 57C56.

If the SDCS fails (such as the LPSI pumps and/or the associated CCW pumps) due to a steam line break, several alarms will be annunciated in CR57C and CR64A.

The alarms and indications listed below will help the operator diagnose the loss of SDC:

Reactor Core exit temperature is indicated on QSPDS Page 633 for CETs and Page 721 for HJTCs.

RWLP thermocouple reference temperature is a measure of RX Core I temperature just above the Upper Fuel Alignment Plate.

CR57 2(3)TI-0303-1,2(3)TI-0303-2,2(3)TR-0351 A - SDCS Temperature e 57C39 "SDCS FLOW LO"

LPSI/CS Motor Amperage Fluctuating For SEB flooding, the following alarms will annunciate in the CR:

57C46 " SAFETY EQPT BLDG TRAIN A FLOODING"

57C56 " SAFETY EQPT BLDG TRAIN B FLOODING" If CCW fails, the following alarms will annunciate in the CR57:

e 64A37 " SHUTDOWN HX TRAIN A CCW FLOW LO"

64A38 " SHUTDOWN HX TRAIN B CCW FLOW LO"

64A39 "CCW PUMP MOTOR BRG TEMP Hl" Maximum allowable time (T ):

8 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Post-diagnosis action time (T ) :

4

OPERATOR ACTION: Operator to Align SFP Cooling to the RCS within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months given loss of SDC.

BASIC EVENT / EVENT TREE: OP/SO2SL4,SO2SL6,SO2CC6,SO2C10,SO2FR3; OP1/SO2CW7,SO2CW4;OP2/SO2CC4;C/SO2FR6 Barrier Event i Tree OPERATOR ACTION

SUMMARY

DATA SHEET )

l l

In about 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months the operator will be able to accomplish the following l alignment task: a) Align the Spent Fuel Pool Cooling to recirculate the RCS l (per 01 SO23-3-2.6.1 Attachments 15 & 16). Once the above task (a) is ,

l complete, the operator would complete the following task if CCW were failed: l l b) Align cooling to the SFP heat exchangers from the opposite Unit CCW per 8023-13-23 Attachment 2 or 3.

Diagnosis Time (To = T , - T, - T)i :

l l To = 12 - 8 .08 = 3.92 or 3.9 Hours l

V. COMPETING ACTIONS:

Isolation of the initiating event, i.e. CCW line break, CWS pipe break, Aux.

Steam Line break.

! VI. PRECEDING RELATED ACTIONS:

l None.

l l l Vll. CONSEQUENCES OF FAILING TO PERFORM ACTION: l Failing to perform this action within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months will lead to bulk boiling in the refueling pool and is conservatively assumed to lead to core damage with no other recovery measure considered.

Vill. CONSEQUENCES OF PERFORMING ACTION:

l l Operator action to align SFP cooling to the RCS within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months will provide an alternate method of cooling the core.

4 5

l

OPERATOR ACTION: Operator to Align SFP Cooling to the RCS within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months given loss of SDC.

BASIC EVENT / EVENT TREE: OP/SO2SL4,SO2SL6,SO2CC6,SO2C10,SO2FR3; OP1/SO2CW7,SO2CW4;OP2/SO2CC4;C/SO2FR6 Barrier Event Tree l

I OPERATOR ACTION

SUMMARY

DATA SHEET IX. CREW TRAINING AND EXPERIENCE: I

[ Provide ranking of 0 thru 5 (0 being none,1 being poor or not practiced,5 being very good)] !

l l

SIMULATOR CLASSROOM PLANT EXPER.

IDENTIFY 5* 5* 1 DIAGNOSIS 5* 5* 1 RESPONSE 5* 5* 1

The Alarm Response Instruction procedure is practiced regularly in the simulator training. Operators are familiar with this alignment (Ref: Based on an interview with an operator).

X. CLARITY OF APPLICABLE PROCEDURES:

All applicable procedures are clear procedures. !

l I

XI. AVAILABILITY OF RELEVANT INDICATIONS i i

l All relevant indications are expected to be available. ;

Xil. CONSIDERATIONS FOR" LOCAL" ACTIONS:

o Is required action proceduralized?

Yes. SO23-15-57.C procedure instructs that an operator be dispatched to l the affected area and investigate, then isolate source of leakage (if possible). In the event of loss of SDC, SO23-13-15(Loss of SDC) and ,

SO23-3-2.6.1 provides a step-by-step procedure in aligning the SFP cooling system to the RCS. i 1

o How accessible is the component from the control room? Considering distance and number of security doors, estimate time to reach component .

from the control room. l 6

OPERATOR ACTION: . Operator to Align SFP Cooling to the RCS within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months given loss of SDC.

BASIC EVENT / EVENT TREE: OP/SO2SL4,SO2SL6,SO2CC6,SO2C10,SO2FR3; OP1/SO2CW7,SO2CW4;OP2/SO2CC4;C/SO2FR6 Barrier Event

_ Tree OPERATOR ACTION

SUMMARY

DATA SHEET l

All of the equipment is within <30 minute reach, however it is assumed that it will take about 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months to complete the alignment necessary as mentioned in Section Ill. It is expected that due to the emergency situation that there will be several crews assisting in accomplishing this task. Also, once the event occurs, it is expected that Health Physics would be notified and provide the necessary support without delay.

If steam hazard reached the penetration area, it is expected that it will dissipate within one hour from the time of the accident. Similarly if the CWS flooding were to reach the penetration area, it is expected to recede below 9' 8" within one hour. The valves MUO33 and MU994 are located in elevation 9' Penetration Building (about 2' above floor level, i.e., ,

I elevation 11') and will be accessible after one hour from the time of the event.

o is action considered to be relatively simple or complex 7 Complex. However it is expected that several experienced and senior personnel would be involved, not only in the control room but also in carrying out the task. Since the affected unit is in Mode 6 with the refueling cavity level >23', restoring shutdown cooling is expected to be the highest priority.

o Are any special tools required (keys, wrenches, etc.)? If so, will they be readily accessible during the accident sequence?

Keys will be required to unlock valves that are chained locked. These keys are all readily accessible in the CR area.

o Will performance of the action require entering a harsh environment where protection clothing or equipment is necessary?

Yes, some valve locations are in high radiation areas and protective clothing is required. However, it is expected that once the event occurs, Health Physics would be notified and provide the necessary support without delay.

7

OPERATOR ACTION: Operator to Align SFP Cooling to the RCS within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months given loss of SDC.

BASIC EVENT / EVENT TREE: OP/SO2SL4,SO2SL6,SO2CC6,SO2C10,SO2FR3; OP1/SO2CW7,SO2CW4;OP2/SO2CC4;C/SO2FR6 Barrier Event Tree OPERATOR ACTION

SUMMARY

DATA SHEET o Are there any unique aspects of the action which could affect the likelihood of successful completion (i.e., requires more than one person, must be performed concurrent with other actions, requires communication with the control room, etc.)?

The operator action (as shown in 8023-3-2.6.1 Att.15 & 16) requires more than one person. It is expected that procedural actions are being performed concurrent with other actions and requires communication with the control room. It is expected that several teams or crews will be sent out to perform the alignment. For example, two person team is performing electrical alignment and verification, while the other team is performing valve alignment and verification.

Xill. COMMUNICATIONS AND OPERATOR AVAILABILITY:

All normal means of communications are expected to be available.

XIV. OPERATOR OVERSIGHT / CHECKING:

It is expected that a two man team will provide action and checking of a task.

XV. STRESS LEVEL:

1 Moderately high stress level is expected initially.

XVI. SPECIFIC QUESTIONS ABOUT ACTION: i None.

XVil. OTHER INSIGHTS:

None.

XVill.

REFERENCES:

1 Calculation M-120.15, Rev. 6, " Plant Flooding Analysis Review" 8

OPERATOR ACTION: : Operator to Align SFP Cooling to the RCS within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months given loss of i SDC.

BASIC EVENTIEVENT TREE: OP/SO2SL4,SO2SL6,SO2CC6,SO2010,SO2FR3; ;

OP1/SO2CW7,SO2CW4;OP2/SO2CC4;C/SO2FR6 Barrier Event l Tree. l l

i OPERATOR ACTION

SUMMARY

DATA SHEET {

i I ,

2 Calculation N-0220-029, Rev. O, dated May 1993 RCS Heatup Following Loss of SDC. l i

3 SO23-15-57.C, Rev.1 - Annunciator Panel 57C, Vital Bus Power l l 4 SO23-13-15, Rev. 3 - Loss of Shutdown Cooling, AOI i

j 5 SO23-3-2.6.1, Rev. 0 - CS/SDC/SFP Cooling Crosstie Operation

) 6 SO23-13-23, Rev.1 - Loss of Spent Fuel Pool Cooling :

] 7 SO23-3-2.11, Rev. 6 - Spent Fuel Pool Operations A

8 SO23-15-61.A, Rev.1 - Annunciator Panel 61 A, Firewater / Rad Monitors 9 E-mail from R. C. Scott to M. E. Motamed dated 5/30/96, Time-to-boil after Loss of SDC 10 days after shutdown from full power.

i l

1 l

l

. l l

9

POST-LNITIATOR HUMAN ERROR PROBABILITY CALCULATION WORKSHEET BASIC EVENT NAME: HUMAN ACTION DESCRIPTION:

Operator to Aligns SFP Cooling to Recirculate the RCS within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

, OP-SO2SL4/SO2CC6/SO2C10; OPI-SO2Cll7/SO2CW4 OP2-SO2CC4: C-SO2FR6 Event Tne l PROCEDURAL SUPPORT DETERMINATION:

l STEPS 1 & 2: Is the post-initiator human action supported by written procedures? Circle yes or no below.

l Xes: List Applicable Procedures: SO2-13-15. Loss ofSDC: SO23-15-57.C . " Annunciator Panel 57C. ntal Bus Power": SO23 l 2.6.1: SO 23-13-23.

No: Assign Total Failure Probability (F,) = 1.0.

REQUIRED TIME RELATIONSHIP DETERMINATION:

STEP 3. Determine maximum allowable time:

Maximum Allowable Time (T,) = 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months identify method of determmmg T,, (Judgement,, RETRAN): SO23-13-15. Loss ofSDC : E-mail from R.C. Scott to Af.E.Afotamed. Time-to-boil after Loss ofSDC 10 davs after shutdown imm fullvower.

STEPS 4 - 8: Determine the diagnostic time:

Post-diagnosis Action Time (T,) = 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months Identify method of determmmg T (Judgement, walk-thru, simulator, etc): Walkthme interview with an overato_r.;

Procedures SO23-13-15. SO23-3-2.6.1. & SO23-13-23: Alarm Response Procedure SO23-15-57.C Available Diagnosis Time (TJ = T.,- T, = 12 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months Assumptions:

DIAGNOSIS HEP DETERMINATION: (start here)

STEP 9. 9a) Select the initial diagnosis IEP from Figure 7-1 or Table 8-2 (NUREO/CR-4772)..

HEPa = JE-5 Using AfedianJointHEPFigure 7-1(NUREGER-4772).

9b) Is more than 1 abnormal event involved as defined in Table 8-1, Step 9b? Yes &

If yes, adjust liEP per Step 9B (Table 8-1) and Table 8-2 & 8-4.

IEP aw= 4E-5 (EF=30) 9c) Adjust HEP based on Table 8-3 guidelines: (Circle one) Upper Lower BDXual IIEPw = 4E-5 9d) Is diagnosis HEP driven by symptom oriented Eol? (Circle one) Yes &

If Yes/ adjust 1-EP to lower bound (Figure 7-1).

IEPaw = 4E-5 9e) Does IEP involve knowledge of critical RCS/ Containment parameters? (Circle one) Yes &

If no, go to step 9g. If parameters are committed to memory, use lower bound values in Figure 7-1 or Table 8-2. Otherwise use nominal values. Use Table 8-3 to adjust the new values, as appropriate.

IEPg a = (Circle one) Iower Nominal 10

l l

9f) Not applicable.

9g) Is diagnosis e: Tor forHEP credible? (Circle one) Yes @

If'yes,' wvite last adjusted HEP from Steps 9a - 9e as the fmal diagnosis HEP below and continue to Step

10. If'no,' assign ' Final Diagnosis HEP' = 0.0 and discuss below. 1 Final Diagnosis HEP (median) =12 FinalDiagnosis HEP (mean) =19. !

1 Assumptions: Diaenosis error was judeed not credible due to amole time available(4 hrs) in determinine the cause of the event olus tlg numemus indications available.

POSLDIAGNOSIS HEP DETERMINATION:

STEP 10: As defined in Step 10 of Table 8-1, identify type of post-diagnosis task and stress level: l Dynamic Sten-by-sten (Circle one)

Extremely high Moderately hieh (Circle one)

Based on type of task and stress level, select HEP (s) for post-diagnosis action HEP (s) from Table 8-1. [ Note: If time stress is present or if this task is required as a result of an ineffective initial task, assess applicability of doubling rule (Step 10g, Table 8-1). Ifyes, discuss in assumptions below.]

Post-Diagnosis Action HEP (s)(median) = 2E-2(Initial error) x 0.2(checker) x 0.2(2nd checker}= 8E-4 (EF=S)

Table 8-5 Items 3 and 6. andludeement Post-Diagnosis Action HEP (s)(mean) = 1.29 E-3 Assumptions: It is assumed that there will be amole th.:e to check and verify alienment riven that Tmax= 12 hrs .

TOTAL FAILURE PROBABILITY (Fr) DETERMINATION:

STEP 11: Perform step i1 of Table 8-1 using mean values: ,

F, = FinalDiagnosis HEP + Post-Diagnosis Action HEP (s) = 0.0 + 1.29E-3 = L29E-3

' [ Note: If the calculated value of F, exceeds 1.0, use 1.0 ]

Note: A HEP of1.5E-3 was used be the Event Tree.

l Prepared by: Z. S. Roldan Checked By: w[b

/

Date: 5-31-% Date:/ 4 -/ /8 -%

cNOTE: For all figures and tables, refer to NUREO/CR-4772. " STEPS" refer to Table 8-1 of NUREG/CR-4772.

11

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