NLS2009057, Nedc 87-131B, Revision 8, Cooper Nuclear Station, 250 Vdc Division II Load and Voltage Study.

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Nedc 87-131B, Revision 8, Cooper Nuclear Station, 250 Vdc Division II Load and Voltage Study.
ML092300634
Person / Time
Site: Cooper Entergy icon.png
Issue date: 11/20/2002
From: Mccormack M
ERIN Engineering & Research
To:
Office of Nuclear Reactor Regulation
References
NLS2009057 NEDC 87-131B, Rev 8
Download: ML092300634 (30)
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Text

NLS2009057 Enclosure 4 NEDC 87-131B, Revision 8,250 VDC Division II Load and Voltage Study Cooper Nuclear Station, Docket No. 50-298, DPR-46

ATTACHMENT 1 DESIGN CALCULATION COVER SHEET COPY Page lof 4

Title:

250 VDC Division II Load and Voltage Study Calculation Number: 87-131B CED/EE Number: EE 02-040 System/Structure: EE Setpoint Change Number: N/A Component: Various Discipline: Electrical Classification: [ X J Essential; [ ] Non-Essential SQAP Requirements Met? [X] Yes; [ ] N/A

Description:

]his NEDC documents the sequence of events on the Division II 250 Volt DC system for the LOOP/LOCA, SBO and A~ppendix R scenarios at CNS. In addition, this NEDC determines the terminal voltage at the devices of the 250 Vdc Division II system and verifies adequate voltage is available for components to perform their safety function. This zalculation also provides the basis for the battery test load profile.

Revision Summary:

Revised to use EDSA 2.95 as analysis software. Separated Load profiles to show individual loading for LOCA, SBO, and kppendix R scenarios. Added battery testing load profile. Performed minor correction of equipment load, cable data, Uhermal overload relay data, added control circuits for Turbine Building Starter Rack loads, clarified requirements, assumptions, and methodology.

Raised Aging Coefficient from 0.80 (80%) to 0.90 (90%) consistent with Technical Specification Surveillance Requirement 3.8.4.8.

Incorporate changes from Revision 1 of NEDC 96-039, "DC Motor Operated Valve Stroke Time." The Design Calculation

,ross-Reference Index sheet in NEDC 96-039 identifies NEDC 87-131A, B, C and D as affected documents and requiring

,hange.

EJ 99-063 reviewed and determined to not require calculation incorporation as it was applicable for a temporary nodification no longer installed.

ncorporated changes to address the following NAIT Items:

Xther 4-03235 - Revise RPV level setpoint references to use generic levels (Level 1,2,3, etc.) rather than actual values in nches.

'NS Personnel edited Appendix F of ERIN submittal to change loads HPCI-MO-19 and HPCI-MO-21 to normal running turrent rather than Locked Rotor Current since modeling the running current for the entire time period will remain a

onservative assumption.

"NS Personnel alsoedited Appendix P of ERIN submittal to 're-run' the test profile to include the 0.90 aging factor.

this change is consistent with the analyzed scenarios as well as conservative with respect-to the calculations of record.

8 1 ERIN Engineering & Ken Cohn Mike McCormack Research Company X42/

,i/,/

6/6/02 4~ Il/?

11" 7 Rev. Status Prepared By/Date Reviewed By/Date Approved By/Date Number Status Codes

1. Active 4. Superseded or Deleted

) 2. Information Only 5. OD/OE Support Only

3. Pending 6. Maintenance Activity Support Only PROCEDURE 3.4.7 REVISION 20 PAGE X OF XX

ATTACHMENT 2 DESIGN CALCULATION CROSS-REFERENCE INDEX I Page: 2 of 4 NEDC: 87-131B Rev. Number: 8 Nebraska Public Power District DESIGN CALCULATION CROSS-REFERENCE INDEX ITEM REV. PENDING CHANGES NO. DESIGN INPUTS NO. TO DESIGN INPUTS 1 NEDC 91-044 4 None 2 NEDC 91-197 1 None 3 NEDC 93-022 5 EJ 96-144, EJ 97-87, EJ 97-101, EJ 97-72 REV. 1, EJ 98-66, EJ 98-67, EJ 198-68, EJ 97-121 thru 124 4 Procedure 5.3SBO 2 None 5 STP 87-013 0 N/A 6 STP 92-034 0 N/A 7 Tech Spec 3.8.4.8 178 1

) 8 Dwg 3058 N41 None 9 Dwg E507 Sht. 211A N07 None 10 Dwg E507 Sht. 212 N07 None 11 CNS Procedure 6.EE.609 8 None 12 CNS MOV Program Plan 6 None 13 NEDC 91-238 2 None 14 15 t *1- I I 4- .4 1 4. .4 4 ~6*

PROCEDURE 3.4.7 REVISION 20 PAGE X OF XX

.j~W' ATTACHMENT 2 DESIGN CALCULATION CROSS-REFERENCE INDE Page: 3 of 4 NEDC: 87-131B Rev. Number: 8 Nebraska Public Power District DESIGN CALCULATION CROSS-REFERENCE INDEX ITEM NO. AFFECTED DOCUMENTS REV. NUMBER 1 NEDC 91-094 4 2 NEDC 93-022 5 3 NEDC 88-298 4 4 SBO Coping Analysis for CNS 2 5 DCD-35 2 6 Technical Specification Bases, Section 3.8.4 0

__ I _ I_____

4 4 4 4

)

I PROCEDURE 3.4.7 1 REVISION 20 _ PAGE X OF XX I

ATTACHMENT 3 AFFECTED DOCUMENT SCREENING Page: 4 of 4 NEDC: 87-131B Rev. Number: 8 The purpose of this form is to assist the Preparer in screening new and revised design calculations to determine potential impacts to procedures and plant operations.© SCREENING QUESTIONS YES NO UNCERTAIN

1. Does it involve the addition, deletion, or manipulation of a [I [X] [1 component or components which could impact a system lineup and/or checklist for valves, power supplies (breakers), process control switches, HVAC dampers, or instruments?
2. Could it impact system operating parameters (e.g., [I temperatures, flow rates, pressures, voltage, or fluid chemistry)?
3. Does it impact equipment operation or response such as [I [X] []

valve closure time?

[] [x]

4. Does it involve assumptions or necessitate changes to the []

sequencing of operational steps?

5. Does it transfer an electrical load to a different circuit, or [] [X] []

impact when electrical loads are added to or removed from the system during an event?

[] [X]

6. Does it influence fuse, breaker, or relay coordination?

[] IX] []

7. Does it have the potential to affect the analyzed conditions [LI of the environment for any part of the Reactor Building, Containment, or Control Room?

[X] []

8. Does it affect TS/TS Bases, USAR, or other Licensing Basis [II documents?
9. Does it affect DCDs? [X] I] []
10. Does it have the potential to affect procedures in any way not already mentioned (see review checklists in Procedure I I [X] I I EDP-06)? If so, identify:

The Station Blackout Coping Assessment, Rev. 2 (Ret# 09666 0008) states that an aging factor of 1.20 (0.80%) is applied in the battery capacity calculations to account for battery degradation and is conservative with respect to Technical Specification, which allows no more than a 15% reduction in rated capacity. This same discussion is also included in DCD-35. CNS Technical Specifications now, however, allow no more than a 10% reduction in rated capacity. This revision utilizes an aging coefficient of 0.90 (equates to aging factor of 1.11) which is consistent with a 10% reduction is capacity.

This revision remains consistent with Technical Specifications. The Coping Assessment and DCD-35 should be revised to clarify the treatment of "battery aging" in the new revision of NEDC 87-131B.

If all answers are NO, then additional review or assistance is not required.

If any answers are YES or UNCERTAIN, then the Preparer shall obtain assistance from the 9 System Engineer and other departments, as appropriate, to determine impacts to procedures and plant operations. Affected documents shall be listed on Attachment 2.

I PROCEDURE 3.4.7 1 REVISION 20 1 PAGE X OF XX

iE L w i ENGINEERING AND RESEARCH, INC.

)

CALCULATION COVER SHEET Project No: 0122-01-0044 Project Name: Update DC Calculations ERIN Calc No.: C0122010044.001 Client Calc No. NEDC 87-131B Revision 8 Client Name: Nebraska Public Power District

Subject:

Revision 8 of 250 VDC Division II Load and Voltage Study Total Sheets (including cover) 216 Computer Standard Computer Program Program No(s). Version/Release No.

Program: EDSA 0 YES E] NO Client's Version 2.95 REVISION RECORDS Rev. Description Orig. Ckd. App. Date 0 Initial Issue See Previous Cover Sheet for Signatures and Dates 1 Revised to Incorporate NPPD Thmasl**,arver Roger W. Moberly ',/, ", 'g Comments TD REMARKS This calculation was performed under the ERIN QA Program consistent with NPPD-CNS Procedures and Practices.

This calculation is a revision of an existing District Calculation. Refer to the District Calculation Cover Sheet (next page) for details of the revision. Complete rewrite of text and appendices.

Nebraska Public Power District DESIGN CALCULATIONS SHEET Page 1of 23 NEDC: 87-131B Preparer: _ ___ Reviewer: Qr,ý V'J\4L(-L Rev. No: 8 Date: 7~~A~4 Date: C- .- =

Table of Contents 1.0 PURPO SE .................................................................................................................................................................... 3 2.0 REQ UIREM ENTS ...................................................................................................................................................... 3 3.0 DESIGN INPUTS / ASSUM PTIO NS ........................................................................................................................ 4 3.1 DESIG N INPUTS .................................................................................................................................................... 4 3.2 A SSUM PTIO NS ...................................................................................................................................................... 5 4.0 M ETH OD OLO GY ..................................................................................................................................................... 6 4.1 SCENARIO DEVELO PM ENT .............................................................................................................................. 6 4.2 SPECIFIC LO ADING DETA ILS ......................................................................................................................... 9 4.3 PO W ER CABLE IM PEDAN CE ......................................................................................................................... 10 4.4 CO NTR O L CIRCUIT IM PEDAN CE ................................................................................................................. 11 4.5 BATTERY CO NNECTIO N IMPEDANCE .................................................................................................... 12 4.6 EDSA INPUT ......................................................................................................................................................... 13 4.7 BATTERY DISCH ARGE PR O FILE .................................................................................................................. 15 5.0 CO NCLUSIONS ....................................................................................................................................................... 17 5.1 RESULTS SUM MA RY ........................................................................................................................................ 17 5.2 D ISCUSSIO N O F RESULTS ............................................................................................................................... 18 5.3 FINAL CO NCLUSIO NS ...................................................................................................................................... 19

6.0 REFERENCES

.......................................................................................................................................................... 20

Nebraska Public Power District DESIGN CALCULATIONS SHEET Page 2 of 23

) NEDC: 87-131B Preparer: - Reviewer:

Rev. No: 8 Date: . n 6,' Date: t, - &_ -no.A-l APPENDICES Appendix A Load Flow/Voltage Drop Results Summary - LOOP/LOCA Appendix B Load Flow/Voltage Drop Results Summary - SBO Appendix C Load Flow/Voltage Drop Results Summary - Appendix R Appendix D One-Line Cable Information Appendix E Not Used Appendix F Scenario Profile Data - LOOP/LOCA Appendix G Scenario Loading Descriptions - LOOP/LOCA Appendix H Scenario Profile Data - SBO Appendix I Scenario Loading Descriptions - SBO Appendix J Scenario Profile Data - Appendix R Appendix K Scenario Loading Descriptions - Appendix R Appendix L Not Used Appendix M EDSA Output - LOOP/LOCA Appendix N EDSA Output - SBO Appendix 0 EDSA Output - Appendix R Appendix P EDSA Output - Service Test Profile Appendix Q Letter from G. Walker (C&D) to A. Bitar (DE&S)

Appendix R Not Used Appendix S EDSA Battery Profile Augmentation Appendix T EDSA Battery Loading Summary Appendix U EDSA Model ECAD One Line Diagram

Nebraska Public Power District DESIGN CALCULATIONS SHEET Page 3 of 23 NEDC: 87-131B Preparer: * ,I "h Reviewer:

Rev. No: 8 Date: _ ,_ __,.-_.[__ Date: (3- G-1.0 PURPOSE This NEDC develops and evaluates event specific profiles that address three design basis events.

These events are LOOP/LOCA, SBO, and a postulated Appendix R fire in fire areas CB-A and CB-D which results in loss of power to the 125 and 250 Vdc battery chargers. The treatment of the Appendix R scenario is necessary to establish a basis for the allowed battery charger power supply repair activity.

The specific purposes of this NEDC are the following:

1) Determine the 250 Vdc Division II equipment start, stop, and run times for the following scenarios:

a) LOCA event with concurrent loss of 250 Vdc battery chargers and loss of off-site power occurring at time t = 0 second and ending at t = 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

b) Station Blackout (SBO) occurring at time t = 0 second and ending at t = 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. (Ref.

6.30.3).

c) Appendix R Fire Scenario with loss of off-site power occurring at t = 0 second and ending at t= 4.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />.

2) Determine the loads on each of the main buses in the 250 Vdc Division II System for the LOOP/LOCA, SBO, and Appendix R scenarios.
3) Determine the terminal voltages at the devices in the 250 Vdc Division II System and verify adequate voltage to perform their safety function for the LOOP/LOCA, SBO, and Appendix R scenarios.
4) Verify adequate voltage exists at the DC Starter Buses for the Motor-Operated Valves (MOVs) in the "CNS MOV Program Plan" (Ref. 6.12).

2.0 REQUIREMENTS All safety related components in the 250 VDC system must have adequate voltage to perform their safety function for the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> LOOP/LOCA and SBO scenarios and the 4.5 hour5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> Appendix R scenario as defined by specific load type below.

1) All 250 Vdc starter rack bus voltages must be greater than the required 125 Vdc required to maintain operability of the Siemens 3TH8 undervoltage relays.

Nebraska Public Power District DESIGN CALCULATIONS SHEET Page 4 of 23 NEDC: 87-131B Preparer: _ _ _ _ Reviewer:

Rev. No: 8 Date: ".4'*' Date: 6 --

2) The 250 Vdc Reactor Building and Turbine Building Starter Rack bus voltage must be greater than 184 Vdc (80% of rated 230V) for proper operation of the Siemens contactors per VM 1026 (Ref. 6.3).
3) All 250 Vdc Division II Starter Racks powering DC MOVs in the CNS MOV Program Plan must have a minimum calculated bus voltage greater than the minimum allowable voltage defined in NEDC 93-022 (Ref. 6.5).
4) The sustained terminal voltage at the motors must be equal or greater than 90% of the motor rating. (Ref. 6.26) 3.0 DESIGN INPUTS /ASSUMPTIONS 3.1 DESIGN INPUTS
1) For motor loads other than MOVs, the circuit resistance is based on two times the power cable length between the starter and the DC motor. The cable size and length is taken from NEDC 91-044 (Ref. 6.2).
2) For non-MOV motors, the running load is based on the calculated brake horsepower requirements of the connected pump. These values are taken from NEDC 91-238 (Ref.

6.4). The brake horsepower requirements of NEDC 91-238 are increased by 10% for conservatism.

3) For motor-operated valves (MOVs), the thermal overload (TOL) resistance is taken from NEDC 93-022 (Ref. 6.5).
4) The battery duty cycle is 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for the LOOP/LOCA and SBO events.
5) The battery duty cycle is 4.5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> for Appendix R (Alternate Shutdown). Section 4.3.3 and Appendix C of the Appendix R Post-Fire Safe Shutdown Topical Design Criteria Document (Ref. 6.30-4) identifies the coping strategies for a postulated fire in each plant area. Only a postulated Appendix R fire in fire areas CB-A or CB-D results in loss of power to the 125 and 250 Vdc battery chargers. The Appendix R compliance strategy for these two fire areas relies upon the Division II DC system and credits a repair activity to restore the associated battery chargers. The postulated battery charger repair activity requires 41/22hours. Therefore, the Division II batteries must support the proper operation of the required system load for this 41/2 hour time period.
6) For opening MOVs, sufficient torque must be produced to operate the MOV during the unseating period. The required torque is related to a minimum required starter rack bus

Nebraska Public Power District DESIGN CALCULATIONS SHEET Page 5 of 23 NEDC: 87-131B Preparer: - Reviewer: ' - *,N Rev. No: 8 Date: _____,, __,__ Date: 6- (-- ::cc-.

voltage, which must be available in order for the MOV to operate. The minimum calculated starter rack bus voltage will be compared to the minimum required starter rack bus voltage defined in NEDC 93-022 (Ref. 6.5) to verify adequate voltage is available for the MOVs to perform their safety function.

7) The 250 Vdc battery is a C&D LCR-25. This is a lead calcium battery with 25 plates/cell (12 positive), 120 cells/bank, and four square posts/cell.
8) The battery discharge characteristics are taken from the C&D Battery Discharge Characteristic Curve D-841 as captured and verified in the EDSA software (EDSA battery profile C&D LCR-25 D841) and as supplemented by this calculation.
9) A worst case ground fault, defined in NEDC 91-197 (Ref. 6.9), of 2.11 amps at 270 VDC is added to the 250 VDC switchgear bus to conservatively account for ground faults in any non-essential circuits in the 250 VDC Division I distribution system.

3.2 ASSUMPTIONS

1) The individual load start and stop times are given in Appendices F through K of this calculation, which list the main events of the scenarios, the ampere value of each load, and the individual assumptions for each load.
2) Cable conductor resistance is conservatively corrected to 75 deg. C because the higher temperatures results in higher resistances and consequently, gives a greater voltage drop.

Most of these loads are intermittent, and the continuous loads are well below the ampacity of the cables. Therefore, a conductor temperature of 75 deg. C is considered adequate for these loads.

3) Based on STP 92-034 (Ref. 6.4), a DC motor powering a pump type load will operate properly during low voltage conditions; however, the power output of the motor will be significantly reduced, which could affect the function of the pump type load. The results of STP 92-034 indicate that for a compound motor, the input current will vary as the input voltage to the 1.01 power and for a shunt motor, the input current will be directly proportional to the input voltage. Although the relationship closely resembles a constant impedance or "ohmic" load, a constant impedance model is not always conservative.

Therefore, a constant current model at rated voltage is used for conservatism.

4) Impedance of internal control wiring and power fuses, disconnect switches and power contacts of contactors are insignificant as compared to the cable and device impedances and are not included.
5) The DC motors supplied from this system have an efficiency of 80% or greater.

Nebraska Public Power District DESIGN CALCULATIONS SHEET Page 6 of 23 NEDC: 87-131B Preparer: _ Reviewer: A *_

Rev. No: 8 Date: _____ _ ______ Date: 6- - i*

6) Motors with a terminal voltage of at least 90% of rated (0.90 x 240V = 216V or 0.9 x 250V=225V) are assumed to produce required horsepower since motors are designed and sized to produce required power with +/-10% of rated voltage.
7) The TOL resistance tends to reduce the amount of current flowing during the critical starting period of operation because the starting load is a constant impedance. During the running period, the motor is modeled as a constant current device so the TOL resistance reduces available voltage to the motor. For conservatism, the TOL is input at rated (250C) temperature. This assures starting load current is not underestimated. During the running period, the conservatism of modeling the motor as a constant current will compensate for any increased resistance of the TOL due to increased temperature.
8) The Bus 1G First Level Undervoltage relays have a one second time delay after sensing a loss of voltage condition to the time when an automatic action is initiated.

4.0 METHODOLOGY The following sections describe the loading scenarios and model details used to perform the system load and voltage study.

4.1 SCENARIO DEVELOPMENT This NEDC develops and evaluates event specific profiles that address three design basis events and the loads thereof on the 250V Division II DC System. These events are LOOP/LOCA, SBO, and a postulated Appendix R fire in fire areas CB-A and CB-D which results in loss of power to both the 125 and 250 Vdc battery chargers. The treatment of the Appendix R scenario is necessary to establish a basis for the allowed battery charger power supply repair activity. The following sections provide a discussion of the scenarios.

References to starting time are intended to apply to the time interval that begins at that value unless specifically stated otherwise. Appendices F through K list the main events in the postulated event sequence.

4.1.1 LOOP/LOCA Scenario A large break, loss of coolant accident (LOCA) is assumed to occur at T=0 seconds.

At the same time, a loss of offsite power (LOOP) occurs. The 0-1 second time interval represents the instrument response delay. As such, the application of the system loads.

in response to the postulated event occurs at T=1 second.

Nebraska Public Power District DESIGN CALCULATIONS SHEET Page 7 of 23 NEDC: 87-131B Preparer: e

  • Reviewer: Q2_

Rev. No: 8 Date: ____., ___, Date: 6- g -A-< 7 The large break will cause the High Pressure Coolant Injection (HPCI) system to be initiated by high containment pressure or low reactor water level. The HPCI system is assumed to initiate first at T=1 seconds on high drywell pressure. Because of the relatively rapid depressurization of the reactor due to the LOCA, the HPCI system will isolate due to low steam pressure. This results in both a start and isolate cycle for the HPCI system. Reactor pressure will be down to 100 psig at approximately 40 to 45 seconds and 50 psig at T=60 seconds (Ref. 6.30-20, Fig. A-lb, Ref. 6.30-6, Fig. 4-7.1),

which will initiate trip of HPCI and RCIC, respectively, on low reactor pressure.

The LPCI injection valves and the associated recirculation pump discharge valve are initiated based on an appropriate reactor pressure permissive signal. Other DC system loads are started because of falling lube oil pressure caused by loss of AC power, e.g.,

main turbine and generator lube oil and seal oil pumps, and reactor feed pump oil pumps Finally there is a random load associated with the potential cycling of the HPCI system for a postulated small break LOCA. This is discussed further in the random load section below.

Appendix G contains a table that provides the bases for the treatment of the load timing for the LOOP/LOCA scenario. Appendix F contains a table for the load sequencing and magnitudes for the LOOP/LOCA scenario.

4.1.2 SBO Scenario A loss of offsite power (LOOP) is assumed to occur at T=0 seconds which initiates a scram. The emergency diesel generators are assumed not to be available for the duration of the event. Since no AC power is available, the batteries supply the necessary DC loads to maintain the plant is a safe condition.

The scram and loss of condensate and condensate booster pumps causes reactor water level to drop which, in turn causes the High Pressure Coolant Injection (HPCI) system to start. The HPCI system is conservatively assumed to initiate at the low reactor water level (Level 2 - Ref. 6.30-21) after a 1 second delay (Ref. 6.30-20) consistent with the LOOP/LOCA event timing. The initiation signals will cause the HPCI valves and pump motors to operate to correctly line up the systems. These systems help bring the reactor water level and pressure under control. Independent failures, other than those causing the station blackout event, are assumed not to occur in the course of the event.

Since there is no significant reactor water loss, the ECST inventory is adequate for this scenario and no transfer to the suppression chamber (torus) will be required (Ref. 6.30-3).

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) NEDC: 87-131B Preparer: Reviewer: K-E .

Rev. No: 8 Date: _ _ _ _ _ Date: 6_____-__-___

2 The SBO coping analysis (Ref. 6.30-3) states that the HPCI system cycles only once, an initial operation in response to low reactor water level and terminated on high water level. Manual action is then credited for securing the HPCI system. At the end of the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> coping duration, a successful EDG start and breaker closure occurs to terminate the SBO event (the EDG controls and breaker loads are powered from the 125V batteries).

Appendix I contains a table that provides the bases for the treatment of the load timing for the SBO scenario. Appendix H contains a table for the load sequencing and magnitudes for the SBO scenario.

4.1.3 Appendix R Fire Scenario Section 4.3.3 and Appendix C of the Appendix R Post-Fire Safe Shutdown Topical Design criteria Document (Ref. 6.30-4) identifies the coping strategies for a postulated fire in each plant area. Only a postulated Appendix R fire in fire areas CB-A or CB-D results in loss of power to the 125 and 250 Vdc battery chargers. The Appendix R compliance strategy for these two fire areas credits a repair activity to restore the associated battery chargers. The postulated battery charger repair activity requires 41/22 hours. Therefore, the Division II batteries must support the proper operation of the required system load for this 41/22 hour time period.

The analysis indicates that the HPCI system will be used for reactor inventory control.

Therefore, the 250 Volt Division II DC System must be able to support the HPCI system and other connected loads consistent with an Appendix R event.

To obtain the worst case loads, it is assumed that off-site power is lost and the EDG is automatically started. It is also assumed that a spurious initiation of the ECCS systems occurs resulting in the opening of the LPCI injection valve and subsequent closure of the associated recirculation pump discharge valve. For a fire in areas CB-A or CB-D, uncontrolled operation of certain plant equipment may occur.

With these assumptions, the Appendix R fire worst case scenario is the same as the LOOP/LOCA scenario except that is 30 minutes longer and that only the Division II 250 Vdc battery is affected.

It should be noted that while the load profile is similar to a LOOP/LOCA scenario, the system voltage acceptance criteria should be derived based only on those loads credited as operating in the Appendix R analysis.

Appendix K contains a table that provides the bases for the treatment of the load timing for the Appendix R scenario. Appendix J contains a table for the load sequencing and magnitudes for the Appendix R scenario.

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Rev. No: 8 Date: .-. /'4, Date: - ::D) 6- :

4.1.4 Random Load To address HPCI operation during a small break LOCA in the LOOP/LOCA scenario, a second HPCI cycles is modeled at T=600 seconds. The test return valve MO-21 and MO-24 are assumed to be manually cycled following the initiation in order to control reactor level by returning excess inventory to the CST and prevent a high level trip of the HPCI system. Similar to the HPCI initiation in response to the large break LOCA (at T=1 second), it is assumed that the HPCI system will initiate with the aux lube oil pump, gland exhaust vacuum pump, injection valve (MO-19), steam admission valve (MO-14), and min-flow bypass valve (MO-25) operating. After the HPCI system is running the test return valves are opened and throttled (MO-24 and MO-21). The test return block valve (MO-24) is opened and remains open therefore its inrush and running current is bounded by the larger throttling test return valve. This throttling occurs in the period after start-up of the HPCI system. This conservatively accounts for the 250 Vdc load for the most limiting LOCA scenario and envelops the 250 Vdc load for a large break LOCA scenario.

During an SBO, HPCI is postulated to cycle only once, at the initiation of the SBO event. This cycle is not considered to be a random load.

To address continuous HPCI operation for the Appendix R scenario, the test return valves (MO-21 and MO-24) 'are modeled as being cycled in order to control reactor level by returning excess inventory to the CST and prevent a high level trip of the HPCI system. The actuation of these valves is modeled using the MO-21 LRA value from T=720 to T=2520 seconds. All HPCI valves are cycled as described above for the random load during LOOP/LOCA scenario, the MO-21 LRA value, which envelops the starting and running loads of the MO-24 valve.

4.2 SPECIFIC LOADING DETAILS Appendices F, H, and I list the individual loads at their rated voltage as follows:

1) MOV Locked Rotor Amps (LRA) - This value is the locked (0 speed) rotor motor current, in amps, at motor rated temperature obtained from NEDC 93-022 (Ref. 6.5). For MOVs that stroke from closed to open, the LRA is only listed at the beginning of the stroke. For MOVs that stroke from open to closed, the LRA will be listed at the beginning of the stroke for initial starting considerations and also at the end of the stroke (without starting resistors) for seating considerations for valves that have a close function and close against a differential pressure. This starting and closing load is treated as a constant impedance load based on the LRA and rated voltage.

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Rev. No: 8 rfln.p Date: ý Date:

2) MOV Running Amps - The MOV motor nameplate current will be used as the running current after the 3 seconds locked rotor period. This will be conservative because the unseating and initial high differential pressure period is complete. This value is approximately the 20% motor torque value on the motor speed-torque curve and is typical for an MOV in the middle of the stroke. MOV running load is treated as a constant during the valve stroke (after the initial 3 seconds) because the current controls the torque, not the terminal voltage. Therefore, MOVs will be modeled as constant current loads. The MOV motor rated resistance is used in EDSA by dividing the motor rated voltage by the motor rated current.
3) Non-MOV LRA - The value used for non-MOV motor LRA loads is ten times the nameplate FLA unless starting resistors are installed. If starting resistors are installed, then two times the nameplate FLA is used, which is conservative because the reduced voltage starter will limit the starting inrush to 1.5 to 2.0 times FLA. This value is also treated as an ohmic load.
4) Non-MOV Running Amps - The value used for non-MOV motor running current is based on the calculated brake horsepower requirements determined in NEDC 91-238. The running load current is calculated using rated voltage values from Appendix F (H, or J), an efficiency of 80%, and the horsepower requirements from NEDC 91-238 multiplied by 1.1 to include a ten percent margin. The standard conversion of 746 watts per horsepower is also used. Consistent with assumption 3.2(3), the motors are modeled as constant current loads at the calculated values shown below.

Running Required Load NEDC 91-238 NEDC 87-131B Hp from Current Description Designation Designation 91-238 (amps)

TG Air Side Seal Oil Back-up Pump LO-P-ASB SOP 19.46 83.17 Main Turbine Emergency DC Oil Bearing Pump LO-P-EB TG-EOP 50 213.70 Reactor Feedwater Pump Lube Oil Pump RFLO-P-ELOA RFP-EOPA 1.86 7.63 Reactor Feedwater Pump Lube Oil Pump RFLO-P-ELOB RFP-EOPB 1.86 7.63 HPCI Turbine Aux Lube Oil Pump HPCI-P-ALOP HPCI-AOP 5.7 24.36 HPCI Turbine Condensate Pump HPCI-P-CP HPCI-SCP 0.9 3.69 HPCI Gland Seal Exhauster Pump HPCI-FAN-GSE HPCI-EVP 1/3 1.42 4.3 POWER CABLE IMPEDANCE Appendix D lists the cable number, circuit length, and calculated circuit resistance from Calculation 91-044 (Ref. 6.2). For MOVs with TOLs, the TOL resistance obtained from

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Calculation 93-022 (Ref. 6.5) is included in the branch resistance. The total branch resistance is equal to: Rbranch = Rcable + RTOL.

The total circuit length is input the EDSA program. For MOV feeders, this is equal to four times the one-way cable length. For non-MOV loads, this is equal to two times the one-way length.

EDSA performs the circuit resistance calculation based on the input parameters and the analysis temperature (75°C).

4.4 CONTROL CIRCUIT IMPEDANCE The controls for the DIV II starters EE-STR-250 (M025B) and EE-STR-250 (53B) are powered from the 250 VDC motive power supply for the starters. The control circuits that automatically operate these MOVs during a LOCA are defined below with their respective cables:

RR-MO-53B Cable ID Size Length (Ft) From To DC522 12 AWG 210 EE-STR-250(53B) RR-MO-53B DC522 12 AWG 210 RR-MO-53B EE-STR-250(53B)

DC523 12 AWG 104 EE-STR-250(53B) TB494 MRB45 12 AWG 400 TB494 BD 9-4 H667 12AWG 151 BD9-4 BD 9-33 H716 12 AWG 54 BD 9-32 BD 9-33 H716 12 AWG 54 BD 9-33 BD 9-32 H667 12 AWG 151 BD 9-33 BD 9-4 MRB45 12 AWG 400 BD 9-4 TB 494 DC523 12 AWG 104 TB 494 EE-STR-250(53B)

Total 1838 (2-way cable length)

Cable DC522 length estimated based on valve power cable DC521 cable length)

RHR-MO-25B Cable ID Size Length (Ft) From To DC518 12 AWG 90 EE-STR-250(25B) RR-MO-25B DC518 12 AWG 90 RR-MO-25B EE-STR-250(25B)

DC519 12 AWG 104 EE-STR-250(25B) TB 492 MRB13 12 AWG 415 TB 492 BD 9-3 RH23 12 AWG 139 BD 9-3 BD 9-33 H716 12AWG 54 BD 9-33 BD 9-32 H716 12 AWG 54 BD 9-32 BD 9-33 RH23 12 AWG 139 BD 9-33 BD 9-3 MRB 13 12 AWG 415 BD 9-3 TB 492 DC519 12 AWG 104 TB 492 EE-STR-250(25B)

Total 1604 (2-way cable length)

Cable DC518 length estimated based on valve power cable DC521 cable length)

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-(6-The controls for all motor loads supplied by the Turbine Building 250 Vdc Starter Rack are powered from the starter rack. The control circuit loads are tabulated in Appendix D. The control circuits include one run from the starter rack to the control switch located in the control room and to local pressure switches. The total two-way circuit length is conservatively assumed to be 4000 feet of 12 AWG wire.

4.5 BATTERY CONNECTION IMPEDANCE The resistance between the battery and the switchgear consists of three components: the inter-cell connections, the inter-rack/level connections, and the cable connections. The cable connections consist of DC16A and DC16B (DC16C is considered an inter-rack connection). The resistance of these cables is determined in NEDC 91-044 (Ref. 6.2). In addition to the cable resistance, connection resistance of 50 micro-ohms is added for each battery termination (total is for all 3 conductors in each cable).

The resistance of the inter-cell connections is based on allowable limits for these connections.

CNS Procedure 6.EE.609 (Ref. 6.28) establishes the "ACCEPTABLE VALUE" for inter-cell connection resistance. The use of the maximum "ACCEPTABLE VALUE" resistance for all battery connections provides a margin that will envelop actual measured connection resistances.

The measured resistances vary due to changes in connection tightness and surface corrosion. This is conservative since it is improbable that all connections will be at their administrative limit simultaneously, therefore, on average the cell resistances would be below this limit.

Per reference 6.22 (Appendix Q), the published "as built" ratings and discharge characteristics for the LCR-25 include the voltage drop across standard connectors torqued to specification, and having a nominal resistance of 15 to 25 micro-ohms. Since this resistance value is 'embedded' in the discharge characteristic curves, they are already accounted for, and need not be included in the cable resistance. Therefore, a value of 15 micro-ohms is used as a conservative value for the intercell connector resistance included in the published ratings and discharge characteristics. In turn, 15 micro-ohms are subtracted from the assumed maximum connection resistance taken from CNS Procedure 6.EE.609 (the ACCEPTABLE VALUE, or administrative limit). The exception to this is the cable connection resistance at the battery terminals, where 15 micro-ohms are not subtracted since these are considered external connections.

The following tabulation documents the battery to switchgear connection impedance. This value is used as the Battery to Switchgear impedance in EDSA.

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Rev. No: 8 Date: Date: 6~ Battery Connection Impedance Inter-cell resistance 110 x (50-15) = 3850 jtf2 Inter-tier cable resistance (29-30, 89-90) 2 x (95-15) = 160 WQ Inter-rack cable resistance (13-14, 45-46, 73-74, 105-106) 4 x (85-15) = 280 ýQ Inter-rack cable resistance (27-28, 31-32) 2 x (140-15) = 250 .Q Inter-rack cable resistance (58-59) (Includes DC 16C) 1 x (265-15) = 250 pQ Cables terminals 2x(50)= 100 pQ Cable DC16A 370 JLQ Cable DC16B 490 j.Q Total resistance 0.005750 92 4.6 EDSA INPUT The following sections provide details of the model and data entry into the EDSA program including cable and thermal overload resistance, loading and battery characteristics.

4.6.1 Circuit Impedance Cable impedances are derived from NEDC 91-044 and are input into the EDSA data.

These values are Okonite annealed copper cable values. These values are entered into the EDSA file "feeder.dt2" at 25 deg. C and only include the resistance. The cable coding includes "OK DC" followed by the wire size, e.g., a number 12 AWG cable is "OK DC #12." The EDSA program corrects the resistance for the analysis temperature set in the "Master" file. For this analysis, the temperature is set at 75 deg. C.

The cable length is input as the total circuit length for each path. For example, MOVs cables are entered as four time the one-way cable length and dc motors are entered as two times the one-way cable lengths. The one-way length is from Appendix D (source NEDC 91-044) and is corrected prior to entry. EDSA uses this number directly as the "RXI" Feeder R Option selected in the job "Master" file. This data is in the EDSA Job file.

The MOV thermal overload relays (TORs) are included as protective devices on the bus side of the feeder cable to the MOV. The corrected values from Appendix D have been input to the EDSA database. These values have been added to the "bkrdata.dat" file and are coded" TOR" followed with the valve number, e.g., for MOV HPCI M19, the TOR is "TOR HP MO 19." The resulting circuit impedance reported by EDSA in the input data print is the combination of the cable and TOR resistance.

M.i: -P q, - **

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The battery connection impedance is input to EDSA as a constant value, by assigning a "0" length to the branch, as determined in Section 4.5.

See Appendix D for additional circuit impedance coding information.

4.6.2 Loads The load magnitude, type and sequencing are input into EDSA as identified in Appendices F through K. Loads that do not operate are shown as "non-load" in the data file. Control loads are input as constant impedances, and MOV and motors are input as starting motors. The system ground detection is included as a load on the switchgear bus. Control loads are modeled with the total circuit length and operating loads to simulate the voltage drop. See Appendix F, H, and J for additional load coding information. This information is in the EDSA Job file.

4.6.3 Battery The analyses uses a verified battery curve contained in the QA approved EDSA database as augmented as described in Appendix S. A C&D type LCR-25 D841 is used as the basis and additional supplemental values are added. The battery type is coded as "LCR-25-NPPD" and is included in the \EDSA295\DATA\ directory as files "Z1QE13K4." Additionally, when creating the "Z1QE3K4" file, EDSA automatically updates files "MANUFACT.MAN" and "C&D.BTB." It should be noted that if the Z1QE3K4 file is copied into the EDSA Data Directory, then both the MANUFACT.MAN" and "C&D.BTB are not automatically updated and should be copied into the Data directory as well. The aging coefficient, number of cells, temperature, and number of positive plates is input for the battery. This information is in the EDSA Job and Data directories.

EDSA corrects for temperature and aging by correcting battery current based on the following formula (Ref. 6.27, See EDSA Help files):

Ibatt X(Temp. Factor Icorr :

I~Aging Coef.)

Where:

Icor = Corrected battery current Ibatt = Nominal battery current Temp. Factor = Temperature correction factor (from IEEE std 450-1987, per Ref.

6.27).

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Aging Coefficient = Fraction of manufacturer's rated battery capacity (e.g. if battery has lost 3% of its rated capacity, the aging coefficient is 0.97)

The battery terminal voltage is calculated using the following correction factors:

a) Temperature Correction factor of 1.04 to allow for a battery room temperature of 70 'F.

b) Aging Coefficient of 0.90 which will allow 10% degradation (90%

capacity) of the battery to account for aging effects. Per CNS Technical Specification Surveillance Requirement 3.8.4.8, battery capacity is required to be 90% of rated or greater.

c) Design Margin Factor of 0.95 which gives a margin of 5% to account for any load variations found during subsequent calculation revisions prior to approval and is acceptable because a revision to this NEDC will be performed prior to adding new loads. Since EDSA does not include the design margin in calculating terminal voltage, the 5%

design margin is combined with the aging coefficient. This results in a coefficient of (0.90 x 0.95) = 0.855.

4.7 BATTERY DISCHARGE PROFILE IEEE 450-1995 (ref. 6.29) describes a service test as a special battery capacity test that may be required to determine if the battery will meet the duty cycle of the dc system; In this case, that duty cycle is a LOOP/LOCA, SBO, or Appendix R load profile. A single test is desired, so a duty cycle that envelops the three profiles will be developed. Since the test profile is different from the load scenario profiles (especially later in the profile), the battery terminal voltage values would be expected to be different than those calculated for each individual profile.

An EDSA Test model is included that reflects the test condition. The EDSA model used to develop the voltage acceptance criteria for the test represents the battery at standard temperature (77°F), without aging. During testing, the test load is connected directly to the battery terminals, therefore, the only cable in the model represents the inter-cell connectors, inter-tier and inter-rack cables. The only load in the model is the constant current load of the test set, which changes foreach time step as required to meet the test profile.

The EDSA DC Load Flow program provides, as an output, the total load and current for each step of the analysis. This load data is calculated using actual loads based on the load flow analysis that included loads dependent on voltage. In addition to the load current at the battery, the battery voltage is also output. This data is compiled for use in establishing a load test

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profile. The test input current values for each time step are the maximum value for that time step taken from the analysis results in appendices M, N and 0. These results are tabulated in Appendix T.

The cable resistance includes all of the inter-cell connectors and associated cables at their administrative maximum values (Ref. 6.28) plus two test connections at 100[LQ. This gives a resistance of:

EDSA Battery Test Model Connection Resistance Inter-cell resistance 110 x (50) = 5500 pfQ Inter-tier cable resistance (29-30, 89-90) 2 x(95) = 190 gQ Inter-rack cable resistance (13-14, 45-46, 73-74, 105-106) 4x85= 340.2 Inter-rack cable resistance (27-28, 31-32) 2x140= 280 gQ Inter-rack cable resistance (58-59) (Includes DC 16C) lx265= 265 gQ Test Connections 2x100= 200 gtQ Total resistance 0.006775 Q It is desired that the service test profile be in full minute increments. Combining the LOOP/LOCA, SBO and Appendix R scenario profiles yields an eight step test profile with periods as follows:

Battery Test Load Profile Development Elapsed Min Rqd. Corrected Test Minimum Period Interval Duration Current\ Current Current Acceptable (amps) (amps) (amps) Voltage (v) 1 0-1 minutes 1 min 1 min 358.3 365.466 366 228.8 2 1-2 minutes I min 2 min 297.1 303.042 304 230.3 3 2-3 minutes 1 min 3 min 210.3 214.506 215 232.6 4 3-4 minutes 1 min 4 min 500.7 510.714 511 225.2 5 4-10 minutes 6 min 10 min 366.6 373.932 374 228.3 6 10-12 minutes 2 min 12 min 554.6 565.692 566 223.2 7 12-42 minutes 30 min 42 min 421.8 430.236 431 225.5 8 41 min - 1 hr 1 min 19 min 1 hr 1 min 345.2 352.104 353 226.6 9 1 hrl min- 4 hrs 179 min 4hrs 115.3 117.606 118 232.0 10 4 hrs- 4.5 hrs 30min 4.5 hrs 115.3 117.606 118 231.4

, Z_

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Rev. No: 8 Date: Date: 6 _-wj o profile. The test input current values for each time step are the maximum value that time step taken T.edfrom the analysis results in appendices M, N and 0. These results ar abulated in Appendix The cable resistance includes all of the inter-cell connectors and associ d cables at their administrative maximum values (Ref. 6.28) plus two test connections at O"Q. This gives a resistance of:

Rsistance Connection Test Model EDSA Battery Inter-cell resistance V1- 110 x (50) = 5500 giQ Inter-tier cable resistance (29-30, 89-90) 2 x (95) = 190 j*Q Inter-rack cable resistance (13-14, 45-46, 73-74, 105-106) 4x85= 340 ptQ Inter-rack cable resistance (27-28, 31-32) 2x 140= 280 pý2 Inter-rack cable resistance (58-59) (Includes DC16C) 1 x 265 = 265 ýtQ Test Connections 2x 100= 200 ýQ Total resistance

,9 0.006775 Q It is desired that the service test profile b in full minute increments. Combining the LOOP/LOCA, SBO and Appendix R scen o profiles yields an eight step test profile with periods as follows:

Battery Te Load Profile Development Ean Min Rqd. Corrected Test Minimum Period Interval Dur Current\ Current Current Acceptable od Time (amps) (amps) (amps) Voltage (v) 1 0-1 minutes /I min 1 min 358.3 365.466 366 229.5 2 1-2 minutes 1 min 2 min 297.1 303.042 304 230.8 3 2-3 minutes/ I min 3 min 210.3 214.506 215 232.9 4 3-4 mines 1 min 4 min 500.7 510.714 511 226.1 5 4-10 nutes 6 min 10 min 366.6 373.932 374 229.0 6 10- minutes 2 min 12 min 662.1 675.342 676 221.8 7 -42 minutes 30 min 42 min 682.8 696.456 697 218.8 8 l/min- hrlmin 19 min I hr 1 min 345.2 352.104 353 226.8

) 9 lhrlmin-4hrs 179 min 4hrs 115.3 117.606 118 232.1 4 hrs - 4.5 hrs 30 min 4.5 hrs 115.3 117.606 118 231.5

  • . r.**:
  • j._,* i*:* ' .- .,=. * : ,,

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The service test profile envelopes the analyzed design basis load profiles. The current values shown in the minimum required current column are the highest value from the analysis results in Appendices M, N and 0 for each profile taken for the full duration of each time step in the test profile. The corrected current column reflects the addition of 2% to the minimum values to account for instrument and test equipment errors. The values are rounded up to the next whole amp. This ensures that the actual test current will envelop the minimum required current profile. The values in the minimum acceptable voltage column represent the minimum acceptable voltage at the end of each time step. A..ditiona.ly,, aging fae-tr or- ign...-

i 9 appli ed ina the dzevel pment of the laoad pr-efile w~h~i.--h.c

.... a -t.bl v . ltag- val... .

- rtritu to sevati eM Il-*o7-

5.0 CONCLUSION

S The EDSA run results, including a data input echo print, are provided in Appendices M, N, 0, and P.

5.1 RESULTS

SUMMARY

The individual load start and stop times are given in Appendices F, H, and J. Cable resistances are provided in Appendix D. Required minimum MOV voltage requirements are from NEDC 93-022 (Ref. 6.5). The required minimum voltage for the pump motors is per Assumption 3.2(6).

From Appendices A, B, C, the minimum bus voltages are provided in the table below. The one line diagram provided in Appendix U depicts the network topology and EDSA analytical model.

The following table summarizes the results of the EDSA runs and the acceptance criteria as developed in the requirements section.

DESCRIPTION EDSA ID Req. EDSA EDSA EDSA Volts Results Results Results Bus # ID LOOP/ SBO App R LOCA HPCI Starter Rack 6 HPCI-BUS 195 191.1 203.8 191.1

("HPCI MOVs")

Reactor Building Starter Rack 4 RX-STRT2 195 195.4 225.3 195.4 (RR-53B)

Reactor Building Starter Rack 30 RX- 195 198.3 225.3 198.3 (MOVs RH-25B) STRK25B Turbine Building Starter Rack 5 TG-STRTR N/A 212.9 220.0 212.9 HPCI Aux. Lube Oil Pump 7 HPCI-AOP 216 188.2 198.8 188.2 HPCI Gld. Seal Cond. Pump 8 HPCI-SCP 225 174.5 203.8 174.5

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Rev. No: 8 Date: Date: A gCC a DESCRIPTION EDSA ID Req. EDSA EDSA EDSA Volts Results Results Results Bus # ID LOOP/ SBO App R LOCA HPCI Gld. Exh. Vac Pump 9 HPCI-EVP 216 178.8 185.7 178.8 RFP EOP 1A 25 RFP-EOPA 225 209.2 216.0 209.2 RFP EOP 1B 27 RFP-EOPB 225 208.4 212.9 208.4 Air Side SOP 23 SOP 216 203.1 210.2 203.1 Main TG EOP 21 TG-EOP 216 209.8 214.7 209.8 RHR-MO-25B CONTROL 18 C-RHR25B 184 197.4 225.1 197.4 RR-MO-53B CONTROL 20 C-RR-53B 184 194.4 225.0 194.4 RFP EOP 1A CONTROL 26 RFP-EOPB 184 209.7 216.7 209.7 RFP EOP 1B CONTROL 28 RFP-EOPB 184 209.7 216.7 209.7 Air Side SOP CONTROL 24 SOP 184 210.3 217.3 210.3 Main TG EOP CONTROL 22 TG-EOP 184 208.4 215.4 208.4 5.2 DISCUSSION OF RESULTS The following provides a comparison of results and the requirements as stated in section 2.0.

1) All 250 Vdc starter rack bus voltages are greater than the required 125 Vdc required to maintain operability of the undervoltage relays; therefore, all calculated voltage dips will not cause operational problems with the motor operated valves due to low motive power voltage.
2) The lowest calculated bus voltage for the any starter rack is 191.1 Volts, which is greater than the 184 Vdc required for proper operation of the Siemens contactors with 230 Vdc coils; therefore, the contactors for control circuits will have adequate voltage to perform their safety function.
3) NEDC 93-022 uses 195.0 Vdc as the minimum allowable starter rack voltage that is required for proper operation of MOVs included in the CNS MOV program with a credited safety function on the 250 Vdc Division H system. These MOVs are powered form the "HPCI Starter Rack" (EDSA Bus #6) and the "Reactor Building Starter Rack (EDSA Bus #4). As indicated in the Results Summary table in Section 5.1, the minimum

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voltage on the Reactor Building Starter Rack is above the minimum required 195V during all periods for all scenarios. The minimum bus voltage on the HPCI Starter Rack is below the required 195V for during specific periods for all scenarios.

Review of the scenarios voltage profiles of Appendices A, B, and C reveal that the below required voltage condition occurs during period 17. During this period, no MOVs that are included in the CNS MOV program with a credited safety function are operating.

During Period 17 of the LOOP/LOCA and Appendix R scenarios, the HPCI Test Return Valve MO-21 is being stroked to throttle flow to prevent the cycling of the HPCI system or pump vibration. This potential operating mode is included in the load profile to account for the load on the battery. Valve MO-21 has no credited safety function and is not included in the MOV or IST programs. The valve is not included in NEDC 93-022. Although the operation of the valve in a throttling manner has been included as a potential operating mode, this is not a credited safety function - operation of HPCI is the credited function (HPCI is credited as cycling as necessary to support reactor level.

The throttling is an operational consideration to reduce the cycling of the HPCI turbine). Consequently, the 195V limit is not applicable to this valve.

Therefore, all safety-related MOVs in the CNS MOV Program Plan including the MOVs that have an active safety function during the LOOP/LOCA, SBO and Appendix R scenarios will have adequate voltage to perform their safety function.

4) Review of the Results Summary Table in Section 5.1 indicates that all of the DC motors will experience periods where the available terminal voltage is less than 90% of rated, that per Assumption 3.2(6), assures proper operation. However, review of the Voltage Drop Summaries (Appendices A, B, and C) and Load Profiles Tables (Appendices F, H, and J), indicates that the low voltages are the result of momentary loads due to MOV and motor inrush currents associated with starting and valve seating. Further inspection shows that during periods proceeding and subsequent to the transient loads, motor voltage is above the 90% or rated level. Requirement 2.4 requires a 'sustained' voltage greater than 90%, all instances of voltages less than 90% are only momentary. Therefore, the voltages are considered acceptable.

5.3 FINAL CONCLUSIONS The final conclusion of this analysis is that all safety-related 250 Vdc components powered from the 250 Vdc Division 11 battery at CNS will have adequate voltage and current to perform their safety function for the LOOP/LOCA, SBO and Appendix R scenarios

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6.0 REFERENCES

6.1 NEDO-24045, Loss of Coolant Accident Analysis Report for CNS 6.2 Cable Resistance values from NEDC 91-044, Rev. 4 "Cable Resistance Calculation for 125Vdc

& 250 Vdc Buses & Loads" 6.3 VM1026 6.4 STP 92-034, Rev. 0 "DC Motor Performance Test" 6.5 NEDC 93-022, Rev. 5 "NED Review of ERIN MOV Electrical Calc C122-89-10.039" 6.6 NEDC 91-078, Rev. 1 "Review of ERIN's System Level Design Basis Review for The High Pressure Coolant Injection System MOVs" 6.7 NEDC 91-244, Rev. 1 "Review of ERIN's System Level Design Basis Review for The Reactor Recirculation System MOV's" 6.8 NEDC 91-080, Rev. 2 "Review of ERIN's System Level Design Basis Review for The Residual Heat Removal System MOV's" 6.9 NEDC 91-197, Rev. 1 "Low Voltage Drywell Penetration Short Circuit Withstand Calculation" 6.10 NEDC 91-238, Rev. 2 "Pump Load Calculation - RCIC Gland Exhaust Pump, TG Air Side Seal Oil Backup Pump, Emergency DC Bearing Oil Pump, Reactor Feed Lube Oil Pump" 6.11 VM#72 6.12 CNS MOV Program Plan, Rev. 6 6.13 Proc. 5.3SBO Rev. 2 "Station Blackout" 6.14 Proc. 5.4.3.2 Rev. 24 "Post-Fire Shutdown.to Cold Shutdown Outside Control Room" 6.15 Drawing 3059, Sh. 3, Rev. NO1, EE-PNL-BB I 125Vdc Load & Fuse Schedule 6.16 Drawing 3059, Sh. 5, Rev. N07, EE-PNL-BB2 125Vdc Load & Fuse Schedule 6.17 Drawing 3059, Sh. 7, Rev. N06, EE-PNL-BB3 125Vdc Load & Fuse Schedule 6.18 Drawing 3059, Sh. 9, Rev. 0, EE-PNL-BB4 125Vdc Load & Fuse Schedule 6.19 Drawing 3059, Sh. 12, Rev. N07, EE-PNL-DG2, 125Vdc Load & Fuse Schedule 6.20 Drawing 3058, Rev. N32, DC One Line Diagram 6.21 Maintenance Work Request 95-3530, Surveillance Procedure 6.EE.609 Performed 2/11/97.

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6.22 Correspondence from G. Walker to A. Bitar, dated 5/1/97 "Technical Specification Limits for Operability, Intercell Connection Resistance 125 Volt and 250 Volt LCR-25 batteries".

6.23 Technical Specification Manual Section 3.8.4.8.

6.24 DCD-35 Rev. 0 "Station Blackout" 6.25 Inverter Final Test Report, P.O. 332834 6.26 General Electric Specification 21A9222, Rev. 1, "Electric Motors, General" 6.27 EDSA Computer Aided Engineering Software for Windows 95/98, NT 4.0 and 2000, Release 2.95 User Manual, Copyright 2000.

6.28 CNS Procedure 6.EE.609, Rev. 8 "125/250V Station Battery Intercell Connection Testing" 6.29 IEEE Standard 450-1995, "IEEE Recommended Practice for Maintenance, Testing and Replacement of Vented Lead-Acid Batteries for Stationary Applications" 6.30 Scenario Development References 6.30.1 NEDC 87-131A, REV 8, 250Vdc Division I Load And Voltage Study 6.30.2 NEDC 87-131B, REV 7, 25OVdc Division II Load And Voltage Study 6.30.3 Station Blackout Coping Assessment, Rev. 2 6.30.4 "Appendix R Post-Fire Safe Shutdown Topical Design Criteria Document" 6.30.5 Flow Diagram - Residual Heat Removal System (RHR) B5700*2040 Sh 1, Rev N69, B5700*2040 Sh 2, Rev N10 6.30.6 NEDO-21335, July 1976, "Cooper Nuclear Station Loss-of-Coolant Accident Analysis in Conformance with 10 CFR50 Appendix K with Modified Low Pressure Coolant Injection" 6.30.7 NEDC 96-039, Rev. 1 "DC Powered Motor Operated Valve Stroke Time" 6.30.8 3071; Rev N22, Control Elementary Diagram 6.30.9 RHR System Elementary; G0800*791E261 Sh 1, Rev N15, G0800*791E261 Sh 2, Rev N12, G0800*791E261 Sh 3, Rev N24, G0800*791E261 Sh 4, Rev N15, G0800*791E261 Sh 5, Rev N17, G0800*791E261 Sh 6, Rev N06, G0800*791E261 Sh 7, Rev N14, G0800*791E261 Sh 8, Rev N19, G0800*791E261 Sh 9, Rev N05, G0800*791E261 Sh 10, Rev N18, G0800*791E261 Sh 11, Rev Nll, G0800*791E261 Sh 12, Rev N14, G0800*791E261 Sh 13, Rev N07, G0800*791E261 Sh 14, Rev, N15, G0800*791E261 Sh 16, Rev N07, G0800*791E261 Sh 17, Rev N13, G0800*791E261 Sh 18, Rev N10, G0800*791E261 Sh 20, Rev N12,

Nebraska Public Power District DESIGN CALCULATIONS SHEET Page 22 of 23 NEDC: 87-131B Preparer: Z4 ez = Reviewer:

Rev. No: 8 Date: _,__ "__ _ _ _ _ Date: -

G0800*791E261 Sh 21, Rev N12, G0800*791E261 Sh 22, Rev' N10, G0800*791E261 Sh 23, Rev N06, G0800*791E261 Sb 19, Rev N21, G0800*791E261 Sh 3A, Rev N05, G0800*791E261 Sh 12A, Rev N05, G0800*791E261 Sh 24, Rev N01 6.30.10 RCIC System Elementary; G0800*791E264 Sh 1, Rev N28, G0800*791E264 Sh 2, Rev N23, G0800*791E264 Sh 3, Rev N16, G0800*791E264 Sh 4, Rev N20, G0800*791E264 Sh 5, Rev N15, G0800*791E264 Sh 6, Rev Nil, G0800*791E264 Sh 7, Rev N13, G0800*791E264 Sh 8, Rev N12 6.30.1 i HPCI System Elementary; G0800*791E271Sh 1, Rev N39, G0800*791E271 Sh 2, Rev N14, G0800*791E271 Sh 3, Rev N17, G0800*791E271 Sh 4, Rev N21, G0800*791E271 Sh 5, Rev N19, G0800*791E271 Sh 6, Rev N15, G0800*791E271 Sh 7, Rev N17, G0800*791E271 Sh 8, Rev N18, G0800*791E271 Sh 9, Rev N15, G0800*791E271 Sh 10, Rev N18, G0800*791E271 Sh IA, Rev N05, G0800*791E271 Sh 6A, Rev N03, G0800*791E271 Sh 11, Rev NOO, G0800*791E271 Sh 4A, Rev N02 6.30.12 Flow Diagram - High Pressure Coolant Injection and Reactor Feed System (HPCI); B5700*2044 Rev N65 6.30.13 NEDC 91-078, REV 2, Review of ERIN's System Level Design Basis Review for High Pressure Coolant Injection System MOVs 6.30.14 ENR 122-98-31-48, RR-MO-25A Breaker Report 6.30.15 ENR 122-98-31-49, RR-MO-53A Report 6.30.16 ENR 122-98-31-50, Inverter Report 6.30.17 ENR 122-98-31-51, RR-MO-53B (Control) Report 6.30.18 ENR 122-98-31-52, HPCI-MO19 Report 6.30.19 ENR 122-98-81, 250 Vdc Non-MOV Motor Load 6.30.20 NEDC-32687P, Rev. 1, Class III, March, 1997 "Cooper Nuclear Station SAFER/GESTR-LOCA Loss of Coolant Accident Analysis" 6.30.21 CNS USAR, Section IV-7.5, "Reactor Coolant Systems", Revision XVI6 6.30.21.1 CNS USAR, Section VII-4.5.4.3, "Core Spray System Pump Control", Revision XVI6 6.30.22 CNS USAR, Section VII-4.5.5.3, "LPCI Mode Pump Control", Revision XVI6 6.30.23 CNS USAR Section VII-4.5.2.4, "HPCI Turbine and Turbine Auxiliaries Control" Dated 8/14/00

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Nebraska Public Power District DESIGN CALCULATIONS SHEET Page 23 of 23

) NEDO: 87-131B Preparer: ~I .i *~ Reviewer: P, A Rev. No: 8 Date: _-______ /_,_ Date: (.(- Z)-J -a-6.31 Drawing 3049, Rev. N15, Turbine Generator Control Elementary Diagrams, Sheet 2 6.32 Drawing 3061, Rev. N09, DC Control Elementary Diagrams, Sheet 2 6.33 NEDC 32675P, Rev. 1, "Cooper Nuclear Station SAFER/GESTR - LOCA Analysis Basis Documentation," Table 6-2, "Event Scenario for 100% DBA Suction Line Break."

6.34 CNS System Operating Procedure 2.2.69.1A, "Residual Heat Removal System Component Checklist (DIV 1)," Rev. 5 6.35 CNS System Operating Procedure 2.2.69.2A, "Residual Heat Removal System Component Checklist (DIV 2)," Rev. 3 6.36 CNS System Operating Procedure 2.2.33A, "High Pressure Coolant Injection System Component Checklist," Rev. 13C1 6.37 CNS System Operating Procedure 2.2.33.1, "High Pressure Coolant System Operation," Rev.

13C1 6.38 CNS System Operating Procedure 2.2.68A, "Reactor Recirculation System Component Checklist," Rev. 11C1 6.39 USAR Table, VI-5-4, "PLANT ECCS PARAMETERS," Dated 03/08/00 6.40 USAR Section VII-4.5.2.5, "HPCI Valve Control," Dated 8/14/00

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