ML050610281

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Exhibit 2, Vermont Yankee - Proposed Technical Specification Change No. 263 - Supplement No. 23 Extended Power Uprate Response to Request for Additional Information, VY MAAP4 Analysis of Adequate NPSH in a LBLOCA
ML050610281
Person / Time
Site: Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date: 02/16/2005
From: Gabor J
ERIN Engineering & Research
To:
Entergy Nuclear Operations, Office of Nuclear Reactor Regulation
References
BVY 05-017 P0166030001-2426
Download: ML050610281 (37)
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Text

BVY 05-017 Docket No. 50-271 Exhibit 2 Vermont Yankee Nuclear Power Station Proposed Technical Specification Change No. 263 - Supplement No. 23 Extended Power Uprate Response to Request for Additional Information VY MAAP4 Analysis of Adequate NPSH in a LBLOCA Total number of pages in Exhibit 2 (excludina this cover sheet) is 36

VY MAAP4 ANALYSIS OF ADEQUATE NPSH IN A LBLOCA Prepared for:

Entergy Prepared by:

ERIflNngineoring and Research, Inc.

an SKF GOrup Conwany FEBRUARY 2005

VYMAAP4 Analysis ofAdequate NPSH in a LBLOCA VY MAAP4 ANALYSIS OF ADEQUATE NPSH IN A LBLOCA P0166030001-2426 Prepared by: 4°fi4 '

Date: 2 -/6, OS-F Reviewed by:

As-

+/-L

-j2 Date:

2L-/C-L9-C, V

Approved by: X (6

) Date: 2-Ito -05 Revisions:

Rev.

Description Preparer/Date Reviewer/Date Approver/Date J. R. Gabor B. Schlenger-Faber.

M. E. Palionis o

Original Release 02-16-05 02-16-05 02-16-05 I

I

- I.

P01 66030001-2426-2116f2005



. 7,

VY MAAP4 Analysis of Adequate NPSH in a LBLOCA TABLE OF CONTENTS Section Paae EXECUTIVE

SUMMARY

.......................................................................................I

1.0 INTRODUCTION

1 2.0 DEFINITION AND ASSUMPTIONS.........................

2 3.0 RESULTS........................

4

4.0 REFERENCES

6 APPENDICES A

HRA INPUT FOR ACTION TO INITIATE SUPPRESSION POOL COOLING B

MAAP4/SHEX CODE COMPARISON C

MAAP4 INPUT FILES I

PO 1 66030001-2426-2116/2005

VY MAAP4 Analysis ofAdequate NPSH in a LBLOCA EXECUTIVE

SUMMARY

This report provides a partial response to EPU Licensing RAI SPSB-C-45 which stated:

The response to RAI SPSB-C-1 provided in Attachment 2 to Supplement 8 indicates that pumps taking suction from the suppression pool have adequate NPSH without requiring credit for containment accident pressure when best-estimate assumptions are used.

The response to RAI SPSB-8 provided in to Supplement 5, Table RAI#8-1, indicates that, as modeled in the PRA, the operators have more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to initiate suppression pool cooling (event KOPACTFL).

Please submit the thermal-hydraulic analyses (both containment response analysis and the NPSH calculation) that support these estimates. Also, please discuss how much time the operator would realistically take to: (a) diagnose the need for suppression pool cooling and; (b) implement suppression pool cooling once the diagnosis is complete. What is the basis for these times (e.g., operator talk-through, simulator exercises)?

This report discusses an analysis performed to estimate the time available to the operators to initiate suppression pool cooling for a specific LBLOCA event.

The analysis assumes the low probability sequence in which containment isolation has failed, thereby eliminating the containment pressure contribution to the pump NPSH.

The Human Reliability Analysis performed for this operator action indicates the time required for diagnosis and manipulation to be on the order of 5 minutes.

A best-estimate thermal-hydraulic analysis concludes that the operators would have on the order of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to establish suppression pool cooling using a single loop of RHR prior to exceeding Core Spray pump NPSH limitations. This is based on a conservative assessment of the energy added due to continued feedwater operation.

A more realistic assessment of the feedwater coastdown would extend this available time by an additional 45 minutes.

In conclusion, a best-estimate thermal-hydraulic analysis provided in this report demonstrates that there is a high likelihood of success for the operators to mitigate this accident prior to exceeding pump NPSH limitations.

i P0166030001-2426-2/1612005

VY MAAP4 Analysis ofAdequate NPSH in a LBLOCA SECTION 1 INTRODUCTION Best-estimate thermal-hydraulic analyses have been performed in support of the VYNPS Probabilistic Safety Assessment (PSA).

These analyses make use of the industry developed Modular Accident Analysis Program (MAAP). Recent calculations have been performed in support of the VYNPS Extended Power Uprate (EPU) submittal and Requests for Additional Information (RAls). In particular, calculations using MAAP Version 4.0.5 have been performed to investigate the available Net Positive Suction Head (NPSHa) for the Low Pressure Core Spray (LPCS) and the Residual Heat Removal (RHR) pumps in a postulated Large Break Loss of Coolant Accident (LBLOCA).

The MAAP4 results represent a best estimate analysis of the time available for an operator to initiate suppression pool cooling for a specific LBLOCA event. As an added conservatism, the containment is assumed to be open, eliminating any back pressure to increase the available pump NPSH. The probability of this type of containment isolation failure case is extremely small.

In support of the use of MAAP4 for this type of analysis, a comparison between MAAP4 and the SHEX (Ref. 1) code was made. A summary of the code comparison is included in Appendix B of this document. The comparison shows excellent agreement between the two codes for similar input assumptions.

A description of the Human Reliability Analysis for the operator action to initiate suppression pool cooling is provided in Appendix A. This description provides the basis for determining how much time the operator would realistically take to: (a) diagnose the need for suppression pool cooling and; (b) implement suppression pool cooling once the diagnosis is complete.

I P0166030001 -2426-2/16/2005

VYMAAP4 Analysis of Adequate NPSH in a LBLOCA SECTION 2 DEFINITION AND ASSUMPTIONS MAAP4 requires two types of input to execute a plant-specific analysis. First, a plant parameter file is required including over 1000 plant input values representing the following major areas:

  • Reactor vessel geometry Core fuel design Emergency injection system characteristics
  • Containment geometry Initial conditions
  • Vessel and containment heat structures
  • Fission product inventory A VYNPS MAAP4 parameter file, VYM405_020305.PAR (Ref. 2) has been developed and utilized in this analysis.

An input file is also required to define the specific assumptions and actions for the desired scenario. Appendix C includes a listing of the MAAP input files utilized for the LBLOCA base case analysis and additional sensitivity calculations.

The following describes the major assumptions and key actions for the base scenario.

Accident Initiation:

Break assumed in the suction of the recirculation loop (4.16 ft2)

  • LPCS and LPCI are available to provide injection No credit for containment overpressure assisting to maintain NPSH of ECCS pumps.

2 P01 66030001-2426-2/16/2005

VY MAAP4 Analysis ofAdequate NPSH in a LBLOCA After total FW injection > 565,077 Ibm:

  • FW Tripped The prolonged feedwater injection is a conservative assumption outlined in OPL-4A (Ref. 3). The attached input file listings provide a detailed description and reference for the sequence-specific assumptions utilized for this analysis.

3 P0166030001-2426-2/1612005

VY MAAP4 Analysis ofAdequate NPSH in a LBLOCA SECTION 3 RESULTS The base case MAAP4 analysis (Case VY0001) was performed using best estimate assumptions throughout, with one exception. A conservative assumption carried over from the OPL-4A (Ref. 3) input was to allow main feedwater to operate until a total injected mass of 565,077 Ibm was obtained. The FW inlet enthalpy history was defined in OPL-4A (Ref. 3) and is shown in the attached input files.

Figure 1 shows the available NPSH for this base run and is labeled "Base RHRILPCI'. Since the core spray and RHR pumps are located essentially at the same centerline elevation, only the RHR pump available NPSH is plotted.

Figure 2 provides the suppression pool temperature plot for the base case and sensitivity runs.

The required NPSH for core spray is 20.44 ft. based on multiplying the manufacturer's recommended value by 0.73. The corresponding limit for RHR/LPCI pumps is 17.52 ft.

Both of these limits are shown in Figure 1. This adjustment was based on tests performed on TVA RHR pumps (Ref. 5) in 1976. The testing included run-out and cavitation tests to demonstrate pump performance while operating in flow and suction pressure regions beyond that certified by the pump manufacturer. The pumps were found to operate acceptably when the available NPSH was degraded to about 60% of the manufacturer's limit for flow rates in the range of 8,000 to 10,000 gpm. For flows in the range of 12,000 gpm, the pumps operated successfully at 73% of the manufacturer's specified limit. It was concluded that the TVA tests are applicable to VY for the reasons that the pumps at both facilities are supplied by the same manufacturer, are of the same type and model, and have very similar operating arrangements (Ref.

6).Based on this information and assuming maximum pump flow for LBLOCA conditions, a conservative limit of 73% of the manufacturer's required NPSH was used.

Given these limits, the base case results indicate that the core spray NPSH limit is not reached until 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> into the event.

4 P01 66030001-2426-2/16/2005

VY MAAP4 Analysis of Adequate NPSII in a LBLOCA A sensitivity case was executed (Case VY0002) in which the FW pump was assumed to be tripped off at the event initiation. This results in a lower amount of energy being deposited into the suppression pool and a longer available time before the core spray pump NPSH limit is reached. If extended operation of the FW system is not assumed (i.e., FW pumps trip at initiation of event), the NPSH limit is not reached until approximately 45 minutes beyond that for the base run.

Two additional sensitivities are included in Figure 1. To confirm that adequate NPSH is available, cases were run assuming that a single loop of RHR was operated in suppression pool cooling mode at 3 and 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> into the event. Both cases show recovery of suppression pool temperature control and avoidance of the NPSH limitation.

In conclusion, the best estimate MAAP4 analysis presented here shows that the operators would have 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> from the initiation of the LBLOCA to initiate a single loop in suppression pool cooling mode in order to maintain adequate pump NPSH.

5 P0166030001 2426-2/16/2005

VYMAAP4 Analysis of Adequate NPSH in a LBLOCA SECTION 4 REFERENCES

1.

GE-NE-0000-0011-1167-01: Project Task Report, Entergy Nuclear Operations Incorporated, Vermont Yankee Nuclear Power Station, Extended Power Uprate, Task T0400: Containment System Response

2.

MAAP4 Parameter file for VYNPS, VYM405_011405.PAR, dated 1/14/2005

3.

DRF-0000-0013-8384:

OPL-4 (Containment Analysis Input Values) For Vermont Yankee Nuclear Power Station EPU/MELLLA+, Rev 1

4.

VYC-0808: Core Spray and residual heat removal Pump Net Positive Suction Head Margin following a Loss of Coolant Accident and an Anticipated Transient Without Scram with Fibrous Debris on the Intake Strainers

5.

TVA Browns Ferry Nuclear Plant Units 1-3, RHR pump Protection Against operation in Excess of Design Run-out, May 17, 1976

6.

Memo, Richard Turcotte (YAEC) to Ed Bums (ERIN), UNPSH Review for VY RHR Pumps - VY IPE", dated January 11, 1993 6

P0166030001-2426-2/16/2005

VYMAAP4 Analysis of Adequate NPSH in a LBLOCA Figure 1 - MAAP4 LBLOCA.w Cont Isol Failure 50 45 40 35 0 30 B

, 25 UL 20 z

15 10 5

0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 Time (hr) 7 P01 66030001-2426-2/16/2005

VY MAAP4 Analysis ofAdequate NPSH in a LBLOCA Figure 2 - Suppressioln Pool Temperature (F) 250 200 LL 150 L..

Ca 0.

Ea 100

I t

lP at 3 hr lL/

' l I l I.' l........

50 0

0.0 1.0 2.0 3.0 Time (hr) 4.0 5.0 6.0 8

P0166030001-2426.2116/2005 8

POI 66030001 -2426-2/1 6/2005

VY MAAP4 Analysis ofAdequate NPSH in a LBLOCA APPENDIX A INPUTS / CONSIDERATIONS FOR HUMAN RELIABILITY ANALYSIS FOR OPERATOR ACTION TO INITIATE SUPPRESSION POOL COOLING PURPOSE The following is a discussion of the inputs and considerations required for a human reliability analysis (HRA) for the operator action to initiate RHR suppression pool cooling (SPC) during transients at the Vermont Yankee (VY) Nuclear Power Plant.

The following discussion is related to initiation of SPC following a plant transient or a LOCA (ATWS scenario issues are not discussed). Although this information is particular to VY, the approach and necessary considerations are generally applicable generically.

INPUTS FOR HRA A variety of HRA methods exist and are employed.in the PRA industry; however, in.--.

general each HRA method requires information on the following to estimate the human error probability (HEP):

  • Procedures
  • Required Tasks
  • Operator Training Relevant Cues
  • Timings Procedures The existence or non-existence of procedures that direct the performance of the action and guide the operators through the action are key to the analysis. Procedures dictate what particular actions will be performed and when the actions will be performed. The lack of an existing procedure for a particular action of interest dramatically increases the A-1 P0166030001-2426-2/16/2005

VY MAAP4 Analysis ofAdequate NPSH in a LBLOCA HEP (e.g., the HEP is often assumed in industry PRAs to be 1.0, or near 1.0, in such cases).

The VY procedure directing initiation of SPC in response to transients or accidents is Emergency Operating Procedure EOP-3, Primary Containment Control. The EOP-3 directions are clear and concise regarding initiation of SPC:

Step Direction PC/TT-1 Control torus temperature below 90F using available torus cooling.

PC/rrT-2 WHEN torus temperature cannot be maintained below 90F, PCfrr-3 Operate all available torus cooling using only those RHR pumps not required for adequate core cooling.

...-...-.The-specific manipulation tasks. required.to.initiate SPC are. outlined..in. a-supporting..

operating procedure OP 2124, "Residual Heat Removal System".

It is also noted that no other cautions are invoked in EOP-3, such that exceeding the required NPSH would not cause the staff to terminate SPC.

Required Tasks The required subtasks that must be performed to complete the action impact the resulting HEP in a number of ways:

  • The greater the number of subtasks, the greater the likelihood of committing an error during the performance of the action
  • The greater the complexity of the subtasks, the greater the likelihood of committing an error during the performance of the action A-2 P0166030001-2426-2/16/2005

VY MAAP4 Analysis of Adequate NPSH in a LBLOCA The number and complexity of subtasks influences the amount of time required to perform the action

  • The location of where the subtasks are performed impacts the error rate due to considerations of operator travel time and access and environmental and lighting issues Initiation of SPC during normal operation (e.g., in response to HPCI/RCIC surveillance tests) can involve more subtasks (e.g., flushing, heat-up) than initiation of SPC as directed by the EOPs. Initiation of RHR SPC in response to EOP direction is the applicable situation for PRAs.

With no LOCA signal present, initiation of SPC in response to a general transient requires the following simple subtasks:

  • Manual initiation of the RHRSW pumps
  • Manual initiation of RHR pumps
  • Manual alignment of MOVs for RHR SPC mode All these are remote actions performed from within the Main Control Room using control switches on the main control boards.

If a LOCA signal is present, the subtasks required for initiation of SPC involve the following additional considerations:

A-3 P0166030001 2426-2/16/2005

VYMAAP4 Analysis ofAdequate NPSH in a LBLOCA

  • Realignment from the LPCI mode after the 5 min. timer occurs on low water level
  • Bypass the 2/3 core height water level interlock (switch on Control Room panel)
  • Containment spray manual override (if drywell sprays are part of the return path, drywell spray usage requires DW pressure >5 psig else a manual override switch on the Control Room panel for DW sprays is required)

Interviews with plant operators are useful in understanding the subtasks that the operators will perform. Multiple operator interviews (involving interviews of operators and Shift Technical Advisors, STAs) and simulator observations have been performed in the past to support the VY HRA (including this particular action).

I_--

V riftV-t Yankee Int-- ieW Influences on Performance Shape Factors Trainer Shift Supervisor SRO Time Required (estimate or observed)

- Diagnosis

< 5 min.

< 5 min.

- Manipulation 30 sec.

30 sec.

An understanding of the tasks is used to support estimation of operator manipulation errors (e.g., selecting the wrong control switch). Manipulation error rates are obtained from industry sources (e.g.; NUREG/CR-1278). Given that the operator-has a large window of available time in which to diagnose and perform the action (initiation of SPC),

the time available to recover from mis-selected switches, and the fact that all subtasks are simple control switch manipulations in the Control Room, the execution error for initiation of SPC in response to a transient or a LOCA is judged to be negligible and is not specifically quantified in the VY HRA.

A-4 P01 66030001-2426-2/16/2005

VYMAAP4 Analysis ofAdequate NPSH in a LBLOCA Operator Training Operator training has an impact on the estimation of operator error rates. If an operator has significant experience in the performance of an action such that the action can be considered "routine", the estimated error rate for the action is minimized in comparison to one in which the operator has never received training and has never performed the action.

Initiation of SPC is performed comparatively often such that it is considered a 'routine" action. The use of RHR for torus cooling is an operation that is performed from the Control Room for operational activities and events the cause pool temperature increases (e.g., HPCI/RCIC flow tests). In addition, the operating staff is well practiced in the initiation of RHR because this action is an element of many simulator exercises that the staff must participate in.

Interviews with plant operators are useful in determining the level of understanding, familiarity and training the operators have with a given action.

Multiple operator interviews (involving interviews of operators and STAs) and simulator observations have been performed in the past to support the VY HRA (including this particular action).

Relevant Cues Operators are alerted to the need to perform certain actions based on available relevant cues, e.g.:.., _A-E

  • Operator monitoring of a parameter Notification by plant personnel In the case of initiation of SPC, the relevant cues are annunciators and operator monitoring of increasing suppression pool water temperature above 90F. The EOPs A-5 P0166030001 -2426-2/1 6/2005

VY MAAP4 Analysis ofAdequate NPSH in a LBLOCA are structured to constantly monitor the suppression pool temperature and to provide feedback to the operating crew.

In addition, at VY the Control Room annunciators alarm at suppression pool temperatures of 88 'F.

In the case of a LOCA, other accident alarm signals (e.g., low RPV water level, high DW pressure) would also alert the operator to the need to initiate SPC.

Timings Understanding the available time in which to perform an action and the amount of time it takes to perform the action is another key element in the assessment of operator error rates. The timings for a particular action are typically defined by the following time windows and milestones:

  • Time of initial disturbance
  • Time of irreversible plant state
  • Total time window
  • Time of cue Manipulation (execution) time Diagnosis time The total time window in which the action may take place is defined by the time of the initial disturbance and the time of the irreversible plant state. The initial disturbance in the case of initiation of SPC is the plant trip or the LOCA which occurs at t=O. The time of the irreversible plant state in the PRA for initiation of SPC during transients or LOCAs is the minimum of the following:

Time at which containment failure occurs due to overpressurization (as defined by the PRA ultimate containment failure curve)

A-6 P0166030001-2426-2/16/2005

VY MAAP4 Analysis of Adequate NPSH in a LBLOCA

  • Time at which RPV repressurizes due to SRV closure at high drywell pressures (applicable to transients with no available HP injection sources)
  • Time at which NPSH is insufficient for Injection systems taking suction off the torus The time of the cue that alerts the operator of the need to perform a particular action is necessary to determine the actual time available to the operator in which to act. The time of the cue is not always t=0. In the case of initiation of SPC during a transient, the cue timing can reasonably be assumed to be t=0 (given operator training and understanding regarding the need and use of SPC in response to a trip), or the time at which the suppression pool temperature reaches 90 "F. The VY HRA assumes the latter.

Like many industry PRAs, the VY PRA uses thermal hydraulic calculations of accident scenarios (using the EPRI MAAP code) to support the estimation of the time of the irreversible state and the time of the operator cue.

The manipulation (or execution) time is an estimate of the time it actually takes the operators to perform the action. This includes travel/access time and the manipulation time associated with performing the activity.

Interviews with plant operators are useful in estimating the execution time for a given action. Multiple operator interviews (involving interviews of operators and STAs) and simulator observations have been performed in the past to support the VY HRA (including this particular action). In addition, VY Job Performance Measures (JPM) were reviewed to support the VY HRA in the estimation of execution time.

The execution time for initiation of SPC per EOP-3 at VY is on the order of 1 minute or less.

The diagnosis time is the time available to the operator to diagnose the plant condition and to determine the proper response.

Diagnosis time is defined as:

[Time of A-7 P0166030001 2426-2/16/2005

VY MAAP4 Analysis ofAdequate NPSH in a LBLOCA Irreversible State] - [Time of Cue] - [Execution Time].

Industry HRA methodology references that provide time-based diagnosis error rates (e.g., EPRI NP-6560L, NUREG/CR-4834, NUREG/CR-1278) are then consulted to determine the diagnosis error.

The total error rate for a particular action is the diagnosis error plus the manipulation error.

A-8 P0166030001-2426-2/16/2005

VY MAAP4 Analysis of Adequate NPSH in a LBLOCA APPENDIX B MAAP4/SHEX Comparison To support the use of MAAP4 for this application, a code comparison was made between MAAP 4.0.5 and SHEX. The SHEX results were obtained from GE-NE-0000-0011-1167-0 (Ref. 1). The comparison was performed for a DBA-LBLOCA event using the results included in Appendix C of the GE document.

The MAAP4 analysis was performed with similar assumptions as in the SHEX analysis, included the following:

  • Large break (4.16 ft2) in the recirc loop
  • Initial suppression pool temperature = 90 IF Initial full power= 1950 MWth Feedwater discharges a total mass of 565,077 Ibm.

Feedwater enthalpy history from OPL-4A

  • LPCI and CS Pump heat from OPL-4A Additional differences exist between the inputs for the two codes; however, the above items are judged to have the most significant impact on the suppression pool heat up.

Figure B-1 shows the comparison between MAAP4 and SHEX for the DBA LOCA scenario. With similar input assumptions,-the calculated suppression pool temperature at 600 seconds compares very well.

MAAP4 predicts a temperature of 161 OF compared to the SHEX prediction of 165 "F.

The reason for this small difference is likely due to additional inputs and boundary conditions that are not the same between the two codes.

B-1 P01 66030001*2426-2/16/2005

VYMAAP4Analysis ofAdequate NPSH in a LBLOCA REFERENCES

1.

Project Task Report, Entergy Nuclear Operations Incorporated, Vermont Yankee Nuclear Power Station, Extended Power Uprate, Task T0400: Containment System Response" B-2 P01 66030001 -2426-2/16/2005

VYMAAP4 Analysis of Adequate NPSH in a LBLOCA Figure B-1: MAAP/SHEX Comparison U.

0 I-at 0

I-CD 0.

E 0

0 0.

0 Ce V

a.0.

(I) 0 Cn 170 160 150 140 130 120 110 100 90 80 0

100 200 300 400 500 Time (seconds) 600 B-3 P01 66030001-2426-2/16/2005

VY MAAP4 Analysis ofAdequate NPS11 in a LBLOCA APPENDIX C MAAP Input Files P0166030001-2426-2/i 6/2005

VY MAAP4 Analysis ofAdequate NPSH in a LBLOCA SENSITIVITY ON TITLE VYOOO1 -

LBLOCA w Isol Fail END PARAMETER FILE vym405_011405.par 25 PARAMETER CHANGE C This parameter forces the plot files to be written using a format compatible with Excel IPLT1 = 5 C Required pump NPSH values obtained from VYV-808,Rev 8, page 10 of 58 C NPSHr values based on maximum flow for CS and RHR pumps C For CS at 4,600 gpm -

NPSHr 28 ft C For RHR at 7,600 gpm -

NPSHr = 24 ft C Values are reduced using a multiplier of 0.73 to reflect conservatisms C This multiplier was obtained from a memo from R. Turcotte (YAEC) to E.T.

Burns (ERIN)

C dated, January 13, 1993 C Core spray NPSHr ZHDLPS(l) = 20.44 FT ZHDLPS(2) = 20.44 FT ZHDLPS(3) a 20.44 FT ZHDLPS(4) = 20.44 FT ZHDLPS(5)

= 20.44 FT ZHDLPS(6) -= 20.44 *FT ZHDLPS(7)

= 20.44 FT ZHDLPS(8) = 20.44 FT C RHR/LPCI NPSHr ZHDLPI(1) = 17.52 FT ZHDLPI(2)

= 17.52 FT ZHDLPI(3) = 17.52 FT ZHDLPI(4) = 17.52 FT ZHDLPI(5) = 17.52 FT ZHDLPI(6) = 17.52 FT ZHDLPI(7) = 17.52 FT ZHDLPI(8) = 17.52 FT C Pump centerline elvations adjusted per VYC-808,Rev 8 ZCLLPI = 215.92 FT ZCLLPS = 215.75 FT C LOCA Elevation at Recirc Pump Suction -

Ref: OPL-4A C (For MAAP representation -

this is the El. where the suction line attaches to the vessel)

ZLOCA = 275.5 FT C Assume FW flow and enthalpy as defined in Table2 EPU of OPL-4A C

OPL-4A (Containment Analysis Input Values) for Vermont yankee Nuclear Power Station C

EPU/MELLLA+, Rev 1, 3/3/2003 WFWCD(1)

= 0.0 LB/HR WFWCD(2)

= 0.0 LB/HR C-1 P0166030001 -2426-211 6/2005

VY MAAP4 Analysis of Adequate NPSH in a LBLOCA C To simulate containment isolation failure assume a C 2 ft**2 opening in the Drywell at t=0 AJUNCO(4) = 2.0 FT**2 C 2

  • normal FW flow from OPL-4A WFWMAX = 1.324E7 LB/HR C From DW Floor to Bottom of Recirc Suction ZNLOC -

40.54 FT C LOCA area -

Ref: OPL-4A ALOCA = 4.16 FT**2 C Set Suppression Pool Initial Temp to 80 F C

Ref: OPL-4A indicates range of 70-90F TWRBO(4) = 80. F C Set SERVICE WATER SUPPLY Temp to 85 F -

Ref: OPL-4A TWSW = 85. F END C FW enthalpy as a function of FW mass injected from Table 2_EPU OPL-4A LOOKUP VARIABLE HFW MWSRC LB HFW BTU/LB

0.

372.57 108919.

333.83 216727.

294.00 303971.

262.43 414054.

223.82 502781.

196.83 569465.

179.04 END C MAAP4 user defined plot file PLOTFIL 50 XHLPCI XHLPCS PRB(2)

TWRB(4)

ZWRB(4)

END START TIME IS 0.

END TIME IS 5. HR PRINT INTERVAL IS 10.

HR INITIATORS C Fail DW JFRB(4)

= 1 BREAK IN PRIMARY SYSTEM (LOCA)

MSIVS LOCKED CLOSED FEEDWATER NO TRIPPING BY MSIV OR BYPASS CLOSURE LPCI LOOP 3 LOCKED OFF CRD PUMP LOCKED OFF C-2 P0166030001-2426-2/16/2005

VY MAAP4 Analysis ofAdequate NPSH in a LBLOCA RCIC LOCKED OFF HPCI LOCKED OFF HPCS LOCKED OFF IEVNT(320) IS TRUE END C Maximum amount of feedwater injected -

Ref: OPL-4A IF MWSRC > 565077. LB FEEDWATER MAN OFF END C-3 P01 66030001-2426-2/16/2005

VYMAAP4 Analysis ofAdequate NPSH in a LBLOCA SENSITIVITY ON TITLE VY0002 -

LBLOCA w Isol Fail, FW trip END PARAMETER FILE vym405_011405.par 25 PARAMETER CHANGE C This parameter forces the plot files to be written using a format compatible with Excel IPLT1 = 5 C Required pump NPSH values obtained from VYV-808,Rev 8, page 10 of 58 C NPSHr values based on maximum flow for CS and RHR pumps C For CS at 4,600 gpm -

NPSHr 28 ft C For RHR at 7,600 gpm -

NPSHr 24 ft C Values are reduced using a multiplier of 0.73 to reflect conservatisms C This multiplier was obtained from a memo from R. Turcotte (YAEC) to E.T.

Burns (ERIN)

C dated, January 13, 1993 C Core spray NPSHr ZHDLPS(l) = 20.44 FT ZHDLPS(2) = 20.44 FT ZHDLPS(3) = 20.44 FT ZHDLPS(4) = 20.44 FT ZHDLPS(5) = 20.44 FT ZHDLPS(6) = 20.44 FT ZHDLPS(7) -

20.44 FT ZHDLPS(8) = 20.44 FT C RHR/LPCI NPSHr ZHDLPI(l) = 17.52 FT ZHDLPI(2) = 17.52 FT ZHDLPI(3)

= 17.52 FT ZHDLPI(4) = 17.52 FT ZHDLPI(S) = 17.52 FT ZHDLPI(6) = 17.52 FT ZHDLPI(7) 17.52 FT ZHDLPI(8) = 17.52 FT C Pump centerline elvations adjusted per VYC-808,Rev 8 ZCLLPI = 215.92 FT ZCLLPS = 215.75 FT C LOCA Elevation at Recirc Pump Suction -

Ref: OPL-4A C (For MAAP representation -

this is the El. where the suction line attaches to the vessel)

ZLOCA -

275.5 FT C Assume FW flow and enthalpy as defined in Table2 EPU of OPL-4A C

OPL-4A (Containment Analysis Input Values) for Vermont Yankee Nuclear Power Station C

EPU/MELLLA+, Rev 1, 3/3/2003 WFWCD(1) = 0.0 LB/HR WFWCD(2) = 0.0 LB/HR C-4 P0166030001-2426-2/16/2005

VYMAAP4 Analysis ofAdequate NPSH in a LBLOCA C To simulate containment isolation failure assume a C 2 ft**2 opening in the Drywell at t=0 AJUNCO(4) = 2.0 FT**2 C 2

  • normal FW flow from OPL-4A WFWMAX = 1.324E7 LB/HR C From DW Floor to Bottom of Recirc Suction ZNLOC = 40.54 FT C LOCA area -

Ref: OPL-4A ALOCA = 4.16 FT**2 C Set Suppression Pool Initial Temp to 80 F C

Ref: OPL-4A indicates range of 70-90F TWRBO(4) = 80. F C Set SERVICE WATER SUPPLY Temp to 85 F -

Ref: OPL-4A TWSW = 85. F END C FW enthalpy as a function of FW mass injected from Table 2_EPU OPL-4A LOOKUP VARIABLE HFW MWSRC LB HFW BTU/LB

0.

372.57 108919.

333.83 216727.

294.00 303971.

262.43 414054.

223.82 502781.

196.83 569465.

179.04 END C MAAP4 user defined plot file PLOTFIL 50 XHLPCI XHLPCS PRB(2)

TWRB(4)

ZWRB(4)

END START TIME IS 0.

END TIME IS 5. HR PRINT INTERVAL IS 10.

HR INITIATORS C

Fail DW JFRB(4) = 1 BREAK IN PRIMARY SYSTEM (LOCA)

MSIVS LOCKED CLOSED FEEDWATER MAN OFF LPCI LOOP 3 LOCKED OFF CRD PUMP LOCKED OFF C-5 P0166030001-2426-2/16/2005

VYMAAP4 Analysis ofAdequate NPS!1 in a LBLOCA RCIC LOCKED OFF HPCI LOCKED OFF HPCS LOCKED OFF IEVNT(320) IS TRUE END C Maximum amount of feedwater injected -

Ref: OPL-4A IF MWSRC > 565077. LB FEEDWATER MAN OFF END C-6 P0166030001-2426-2/16/2005

VYMAAP4 Analysis ofAdequate NPSH in a LB3LOCA SENSITIVITY ON TITLE VY0003 - LBLOCA w Isol Fail, SPC at 3hr END PARAMETER FILE vym405_011405.par 25 PARAMETER CHANGE C This parameter forces the plot files to be written using a format compatible with Excel IPLT1 = 5 C Required pump NPSH values obtained from VYV-808,Rev 8, page 10 of 58 C NPSHr values based on maximum flow for CS and RHR pumps C For CS at 4,600 gpm -

NPSHr = 28 ft C For RHR at 7,600 gpm -

NPSHr 24 ft C Values are reduced using a multiplier of 0.73 to reflect conservatisms C This multiplier was obtained from a memo from R. Turcotte (YAEC) to E.T.

Burns (ERIN)

C dated, January 13, 1993 C Core spray NPSHr ZHDLPS(l) = 20.44 FT ZHDLPS(2) - 20.44 FT ZHDLPS(3) = 20.44 FT ZHDLPS(4) = 20.44 FT ZHDLPS(5) = 20.44 FT ZHDLPS(6) = 20.44 FT ZHDLPS(7) = 20.44 FT ZHDLPS(8) 20.44 FT C RHR/LPCI NPSHr ZHDLPI(1) 17.52 FT ZHDLPI(2)

= 17.52 FT ZHDLPI(3) = 17.52 FT ZHDLPI(4) -

17.52 FT ZHDLPI(5)

= 17.52 FT ZHDLPI(6)

= 17.52 FT ZHDLPI(7)

= 17.52 FT ZHDLPI(8), 17.52 FT C Pump centerline elvations adjusted per VYC-808,Rev 8 ZCLLPI - 215.92 FT ZCLLPS - 215.75 FT C LOCA Elevation at Recirc Pump Suction -

Ref: OPL-4A C (For MAAP representation - this is the El. where the suction line attaches to the vessel)

ZLOCA = 275.5 FT C Assume FW flow and enthalpy as defined in Table2 EPU of OPL-4A C

OPL-4A (Containment Analysis Input Values) for Vermont Yankee Nuclear Power Station C

EPU/MELLLA+, Rev 1, 3/3/2003 WFWCD(1) = 0.0 LB/HR WFWCD(2) = 0.0 LB/HR C-7 0P0166030001-2426-2/1612005

VYMAAP4 Analysis ofAdequate NPSH in a LBLOCA C

C To simulate containment isolation failure assume a 2 ft**2 opening in the Drywell at t=0 AJUNCO(4) 2.0 FT**2 C 2

  • normal FW flow from OPL-4A WFWMAX -

1.324E7 LB/HR C From DW Floor to Bottom of Recirc Suction ZNLOC = 40.54 FT C LOCA area -

Ref: OPL-4A ALOCA -

4.16 FT**2 C

C Set Suppression Pool Initial Temp to 80 F Ref: OPL-4A indicates range of 70-90F TWRBO(4)

= 80.

F C Set SERVICE WATER SUPPLY Temp to 85 F -

Ref: OPL-4A TWSW = 85.

F END C FW enthalpy as a function of FW mass injected LOOKUP VARIABLE HFW MWSRC LB HFW BTU/LB

0.

372.57 108919.

333.83 216727.

294.00 303971.

262.43 414054.

223.82 502781.

196.83 569465.

179.04 END from Table 2_EPU OPL-4A C MAAP4 user PLOTFIL 50 XHLPCI XHLPCS PRB(2)

TWRB(4)

ZWRB(4)

END defined plot file START TIME IS 0.

END TIME IS

5.

HR PRINT INTERVAL IS 10.

HR INITIATORS C Fail DW JFRB(4) 1 BREAK IN PRIMARY SYSTEM (LOCA)

MSIVS LOCKED CLOSED FEEDWATER NO TRIPPING BY MSIV OR BYPASS CLOSURE LPCI LOOP 3 LOCKED OFF CRD PUMP LOCKED OFF C-8 P0166030001-2426-2/16/2005

VYMAAP4 Analysis ofAdequate NPSH in a LBLOCA RCIC LOCKED OFF HPCI LOCKED OFF HPCS LOCKED OFF IEVNT(320)

IS TRUE END C Maximum amount of feedwater injected -

Ref: OPL-4A IF MWSRC > 565077. LB FEEDWATER MAN OFF END -

C INITIATE 1 RHR LOOP in POOL COOLING 3 hrs AFTER LOCA START IF TIM > 10800. S LPCI LOOP 2 AUTOMATIC OPEN/CLOSE LPCI LOOP 2 MAN ON LPCI LOOP 2 TO SUPPRESSION POOL LOCKED OPEN RHR HTX 2 MAN ON END

  • C-9 P01 66030001-2426-2/16/2005

VYMAAP4 Analysis ofAdequate NPSH in a LBLOCA SENSITIVITY ON TITLE VY0004 - LBLOCA w Isol Fail, SPC at 4hr END PARAMETER FILE vym405_011405.par 25 PARAMETER CHANGE C This parameter forces the plot files to be written using a format compatible with Excel IPLT1 = 5 C Required pump NPSH values obtained from VYV-808,Rev 8, page 10 of 58 C NPSHr values based on maximum flow for CS and RHR pumps C For CS at 4,600 gpm -

NPSHr = 28 ft C For RHR at 7,600 gpm -

NPSHr = 24 ft C Values are reduced using a multiplier of 0.73 to reflect conservatisms C This multiplier was obtained from a memo from R. Turcotte (YAEC) to E.T.

Burns (ERIN)

C dated, January 13, 1993 C Core spray NPSHr ZHDLPS(1) = 20.44 FT ZHDLPS(2) = 20.44 FT ZHDLPS(3) = 20.44 FT ZHDLPS(4) = 20.44 FT ZHDLPS(5) = 20.44 FT ZHDLPS(6) = 20.44 FT ZHDLPS(7) -

20.44 FT ZHDLPS(8) = 20.44 FT C RHR/LPCI NPSHr ZHDLPI(1) = 17.52 FT ZHDLPI(2) = 17.52 FT ZHDLPI(3) = 17.52 FT ZHDLPI(4) = 17.52 FT ZHDLPI(5) = 17.52 FT ZHDLPI(6) = 17.52 FT ZHDLPI(7) = 17.52 FT ZHDLPI(8) = 17.52 FT C Pump centerline elvations adjusted per VYC-808,Rev 8 ZCLLPI = 215.92 FT ZCLLPS = 215.75 FT C LOCA Elevation at Recirc Pump Suction -

Ref: OPL-4A C (For MAAP representation - this is the El. where the suction line attaches to the vessel)

ZLOCA - 275.5 FT C Assume FW flow and enthalpy as defined in Table2 EPU of OPL-4A C

OPL-4A (Containment Analysis Input Values) for Vermont Yankee Nuclear Power Station C

EPU/MELLLA+, Rev 1, 3/3/2003 WFWCD(l) _ 0.0 LB/HR WFWCD(2) = 0.0 LB/HR C-10 P0166030001-2426-2/16/2005

VY MAAP4 Analysis ofAdequate NPSH in a LBLOCA C To simulate containment isolation failure assume a C 2 ft**2 opening in the Drywell at t=0 AJUNCO(4) = 2.0 FT**2 C 2

  • normal FW flow from OPL-4A WFWMAX = 1.324E7 LB/HR C From DW Floor to Bottom of Recirc Suction ZNLOC = 40.54 FT C LOCA area -

Ref: OPL-4A ALOCA = 4.16 FT**2 C Set Suppression Pool Initial Temp to 80 F C

Ref: OPL-4A indicates range of 70-9OF TWRB0(4) = 80. F C

Set SERVICE WATER SUPPLY Temp to 85 F - Ref:

TWSW = 85.

F END OPL-4A C FW enthalpy as a function of FW mass injected LOOKUP VARIABLE HFW MWSRC LB HFW BTU/LB

0.

372.57 108919.

333.83 216727.

294.00 303971.

262.43 414054.

223.82 502781.

196.83 569465.

179.04 END from Table 2_EPU OPL-4A C

MAAP4 user defined plot file PLOTFIL 50 XHLPCI XHLPCS PRB(2)

TWRB(4)

ZWRB(4)

END START TIME IS 0.

END TIME IS 5. HR PRINT INTERVAL IS 10.

HR INITIATORS C

Fail DW JFRB(4) = 1 BREAK IN PRIMARY SYSTEM (LOCA)

MSIVS LOCKED CLOSED FEEDWATER NO TRIPPING BY MSIV OR BYPASS CLOSURE LPCI LOOP 3 LOCKED OFF CRD PUMP LOCKED OFF C-1 1 P0166030001-2426-2/1 G2005

VYMAAP4 Analysis ofAdequate NPSH in a LBLOCA RCIC LOCKED OFF HPCI LOCKED OFF HPCS LOCKED OFF IEVNT(320) IS TRUE END C Maximum amount of feedwater IF MWSRC > 565077. LB FEEDWATER MAN OFF END injected -

Ref: OPL-4A C INITIATE 1 RHR LOOP in POOL COOLING 4 hrs AFTER LOCA START IF TIM > 14400. S LPCI LOOP 2 AUTOMATIC OPEN/CLOSE LPCI LOOP 2 MAN ON LPCI LOOP 2 TO SUPPRESSION POOL LOCKED OPEN RHR HTX 2 MAN ON END C-12 P0166030001 2426-2116/2005

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