ML22094A115

Response to a Request for Additional Information Regarding a Revision to Technical Specification 3.3.5, Loss of Power (LOP) Diesel Generator (DG) Start and Bus Separation Instrumentation (EPID No. L-202

ML22094A115
Person / Time
Site:	Beaver Valley
Issue date:	04/04/2022
From:	Grabnar J Energy Harbor Nuclear Corp
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
EPID L-2021-LLA-0156
Download: ML22094A115 (152)

Text

energy Energy Harbor Nuclear Corp.

Beaver Valley Power Station harbor P.O. Box 4 Shippingport, PA 15077 John .l Grabnmr 724-682-5234 Site Vice President, Beaver Valley Nuclear April 4, 2022 10 CFR 50.90 L-22-081 ATTN: Document Control Desk U.S. Nuclear Regulatory Commission Washington, DC 20555-0001

Subject:

Beaver Valley Power Station, Unit Nos. 1 and 2 Docket No. 50-334, License No. DPR-66 Docket No. 50-412, License No. NPF-73 Response to a Request for Additional Information Regarding a Revision to Technical Specification 3.3.5, "Loss of Power (LOP) Diesel Generator (DG) Start and Bus Separation Instrumentation" (EPID No. L-2021-LLA-0156)

By letter dated August 29, 2021 (ADAMS Accession No. ML21242A125), Energy Harbor Nuclear Corp. requested Nuclear Regulatory Commission (NRC) approval of a license amendment request. The proposed change would add notes to Technical Specification 3.3.5 required actions C.1 and D. i, and revise Table 3.3 .5-1 , "Loss of Power Diesel Generator Start and Bus Separation Instrumentation."

By email dated March 9, 2022, the NRC staff requested additional information to complete their review of the proposed change. A response to the NRC staff request is attached to this letter. The enclosures provide the requested calculation excerpts.

There are no regulatory commitments contained in this submittal. If there are any questions or if additional information is required, please contact Mr. Phil H. Lashley, Manager, Fleet Licensing, at (330) 696-7208.

I declare under penalty of perjury that the foregoing is true and correct. Executed on April 4, 2022.

Sincerely, John J. Grabnar

Beaver Valley Power Station, Unit Nos. 1 and 2 L-22-081 Page 2

Attachment:

Response to Request for Additional Information

Enclosures:

A. Calculation No. 8700-E-345, Revision 1, "Voltage and Time Delay Analysis for Unit 1 Undervoltage Protection Scheme."

B. Calculation No. 8700-E-345, Revision 1, Addendum 1, "Voltage and Time Delay Analysis for Unit 1 Undervoltage Protection Scheme."

C. Calculation No. 10080-E-346, Revision 1, "Voltage and Time Delay Analysis for Unit 2 Undervoltage Protection Scheme."

D. Calculation No. 10080-E-346, Revision 1, Addendum 1, "Voltage and Time Delay Analysis for Unit 2 Undervoltage Protection Scheme."

E. Calculation No. 8700-E-271, Revision 3, Addendum 4, "Station Service System Dynamic Stability Study."

F. Calculation No. 10080-E-271, Revision 1, Addendum 6 , "BVPS Unit-2 Transient Stability Analysis."

G. Calculation No. 10080-E-271, Revision 1, Addendum 7, "BVPS Unit-2 Transient Stability Analysis."

H. Calculation No. 8700-DEC-0212, Revision 2, "Beaver Valley Unit 1 4.1 kV Emergency Bus Undervoltage: Trip Feed and Start Diesel Uncertainty Calculations."

I. Calculation No. 10080-DEC-0215, Revision 2, "Beaver Valley Unit 2 4.1 kV Emergency Bus Undervoltage: Trip Feed and Start Diesel Uncertainty Calculations."

J. Calculation No. E-529, Revision 1, "Beaver Valley Units 1 and 2, Degraded Voltage Relay (DVR) Time Delay Relay Instrument Uncertainty."

cc: NRC Region I Administrator NRC Resident Inspector NRC Project Manager Director BRP/DEP Site BRP/DEP Representative

Attachment L-22-081 Response to Request for Additional Information Page 1 of 5 The NRC staff's request for additional information is provided below in bold type followed by the Energy Harbor Nuclear Corp. response.

RAI EEB-1 The NRC staff reviewed the calculations provided by the licensee during the audit and has determined that the following information is needed to support the safety evaluation of the LAR:

a) Summary/Excerpts from Calculation No. 8700-E-345, Rev. 1 for BVPS-1, i.e.,

Background/Objective thru Recommendations [Pages 1 thru 15 of the calculation]

b) Summary/Excerpts from Calculation No. 10080-E-346, Rev. 1 for BVPS-2, i.e., Background/Objective thru Recommendations [Pages 1 thru 16 of the calculation]

c) Summary/Excerpts from Calculation No. 8700-E-271, Rev. 3, Addendum 4 for BVPS-1, i.e., Background/Objective thru Conclusions [Pages 6 thru 13 of the calculation]

d) Summary/Excerpts from Calculation No. 10080-E-271, Rev. 1, Addendum 6 for BVPS-2, i.e., Background/Objective thru Conclusions [Pages 5 thru 12 of the calculation]

e) Summary/Excerpts from Calculation No. 10080-E-271, Rev. 1, Addendum 7 for BVPS-2, i.e., Background/Objective thru Conclusions [Pages 4 and 5 of the calculation]

Response

The requested calculation excerpts are provided as part of this submittal. For the requested Item a, an addendum to Calculation No. 8700-E-345 , Revision 1 was recently developed, and the relevant excerpts are provided in Enclosure B. Furthermore, for Item b, relevant excerpts to an addendum to Calculation No. 10080-E-346, Revision 1 confirming adequacy of the recommended overcurrent relay setting changes are provided in Enclosure D.

Attachment L-22-081 Page 2 of 5 RAI EEB -2 In the following calculations requested in RAI EEB-1 above, certain overcurrent relay replacements and settings changes have been proposed/recommended:

• Calculation No. 8700-E-345, Rev. 1 for BVPS-1

• Calculation No. 10080-E-346, Rev. 1 for BVPS-2 Please clarify whether the overcurrent relay replacements and settings changes, as proposed I recommended in the above calculations, have already been implemented. If not, please provide status and timeline for implementation.

Response

Overcurrent relay replacements and settings changes have not been implemented. The plant modifications are in-progress and the timeline for Unit 2 to complete implementation is by the fall of 2024 refueling outage. The timeline for completion for Unit 1 is by the spring of 2027 refueling outage.

RAI EEB-3 In Calculation No. 8700-E-271, Rev. 3, Addendum 4, for Unit 1 (requested in RAI EEB-1 ), the following Conclusions are made:

"When the SSSTs are unloaded, the secondary-side voltages shall be regulated to within 128.5+/- 1.5 volts.

For accident conditions, the degraded voltage relay time delay shall be greater than 2.5 seconds. This provides adequate time for bus voltages to recover following fast bus transfers and is longer than the voltage transients associated with block starting safety-injection equipment. To minimize the potential for inadvertent relay actuation and to preserve operating margin, the time delay should be as long as permissible. (Refer to Calculation 8700-E-345.)

The dropout voltage of the loss of voltage relays for the safety-related 4160-volt buses shall be less than 80.1 percent of the nominal bus voltage.

This ensures that the relays do not drop out when starting large motors, such as the reactor coolant pump motors. To minimize the potential for inadvertent relay actuation and to preserve operating margin, the dropout setting should be as low as permissible. (Refer to calculation 8700-E-345.)

To be within the bounds of the analysis, SSST taps should be raised such that secondary-side voltages are at least 127 volts before starting the 'A'

Attachment L-22-081 Page 3 of 5 reactor coolant pump. Also, the reset voltages for the loss of voltage relays shall not exceed 90 percent of the nominal bus voltage."

Similarly, in the Calculation No. 10080-E-271, Rev. 1, Addendum 6, for Unit 2 (requested in RAI EEB-1 ), the following Acceptance Criteria is stated:

"Voltage Regulation Band for the SSSTs The SSST voltage regulation scheme is being modified such that the transformer taps are maintained in elevated positions when the transformers are unloaded. This ensures the degraded voltage relays reset following fast bus transfers - without crediting the load tap changers. This addendum establishes an acceptable voltage regulation band for the SSSTs. The minimum voltage is selected such that the degraded voltage relays reset following fast bus transfers. For the degraded voltage relays to reset, voltages at the safety related 4160-volt and 480-volt buses shall recover above 94.14 percent of the ... "

"Maximum Allowable Dropout Voltage for the Loss of Voltage Relays This addendum determines maximum allowable dropout voltage for the loss of voltage relays. The maximum dropout voltage shall be less than the minimum voltage observed at the safety-related 4160-volt buses during reactor coolant pump starts."

Based on Conclusions/Acceptance Criteria in the above Calculations, the staff has interpreted that by manipulating the SSST [station service transformer] (138 kV-4.36 kV-4.36 kV) taps, the minimum voltage at the safety-related 4160 V buses during the "A" reactor coolant pump start(s) can be maintained above the maximum allowable dropout voltage for Loss of Voltage Relays (during non-accident conditions).

According to the LAR, as a precaution to avoid spurious operation of Loss of Voltage Relays, the licensee has proposed to add a TS "Note" to TS 3.3.5 Required Actions C.1 and D.1 to facilitate temporary bypassing of the loss of voltage functions 1 and 2 (up to one hour) while starting a reactor coolant pump.

The staff interprets that although according to Calculations, adequate voltage at the safety-related buses can be provided by manipulating the SSST [station service transformer] taps, the TS Note would provide additional measure/option to the licensee in case it is not able to provide adequate voltage at the safety-related buses by manipulating the SSST taps during "A" reactor coolant pump start(s). Please explain the reasons for the "Note" proposed to be inserted in TS 3.3.5 Required Actions C.1 and D.1 for allowing Functions 1 and 2 to be bypassed up to one hour.

Attachment L-22-081 Page 4 of 5

Response

The staffs interpretation is correct. The calculations demonstrate adequate voltages are available at the safety related buses during reactor coolant pump starts. The option to temporarily bypass the loss-of-voltage functions is a precaution to prevent unnecessarily exercising safety-related equipment. If voltages on the emergency 4160 volt buses drop too low while starting the "A" reactor coolant pump at both Unit Nos. 1 and 2, the loss-of-voltage relays drop out and safety-related equipment is separated from the preferred power source and transferred to the emergency diesel generator.

Provided certain conditions are met, the option to temporarily bypass the loss-of-voltage functions for up to one hour while starting these pumps is a defense-in-depth measure.

RAI EICB-4 In the LAR, the licensee requested to revise the loss of voltage (LOV) nominal trip setpoints (NTSs) and allowable values (AVs) of FUNCTION 1, "4160 V Emergency Bus DG start" and FUNCTION 2, "4160 V Emergency Bus, Bus Separation". In Section 3.1 of the LAR, "Loss of Voltage Relay Settings," the licensee provided the proposed changes of channel statistical allowance (CSA), NTS, and AV values.

Provide the following information regarding the proposed LOV setpoint and allowable values for Function 1 and 2.

a) Summary/excerpts from Calculation No. 8700-DEC-0212 Rev. 2 for Unit 1, 4.1 kV Emergency Bus Undervoltage functions (Trip Feed, Emergency Diesel Generator Start) [Pages 1 - 8 of the calculation].

b) Summary/excerpts from Calculation No.10080-DEC-0215 Rev. 2 for Unit 2, 4.1 kV Emergency Bus Undervoltage functions (Trip Feed, Emergency Diesel Generator Start) [Pages 1 - 8 of the calculation].

NRC staff will review the calculations that determined the proposed LOV, NTSs, AVs, and the uncertainties associated with these settings for Functions 1 and 2, that are shown in the Calculations 10080-DEC-0215 Rev. 2 and 8700-DEC-0212 Rev. 2.

Response

The requested calculation excerpts are provided as part of this submittal.

Attachment L-22-081 Page 5 of 5 RAI EICB-5 In the LAR, the licensee proposes to add Function 5, "4160 V Emergency Bus, Bus Separation," and Function 6, "480 V Emergency Bus, Bus Separation". The AV voltages remain the same as Functions 3 and 4, only the time delay differs. In Section 3.2, "Degraded Voltage Time Delay with Safety Injection Signal," the licensee provided the proposed values of the CSA, NTS, and AV values of the Degraded Voltage Relay (DVR) time delays for Functions 5 and 6.

Please provide the following information:

1. Summary/Excerpts of the Calculation E-529 Rev. 1, for BVPS-1 and BVPS-2, LOV Degraded Voltage (with safety injection signal) [Pages 1 - 7 of the calculation].

2. The relevant calculation information that determined the new DVR time delay setpoints, and the uncertainties associated with these settings for Functions 5 and 6 that are as shown in the Calculations E-529 Rev. 1.

Response

The requested calculation excerpts are provided as part of this submittal.

Enclosure A L-22-081 Calculation No. 8700-E-345, Revision 1, "Voltage and Time Delay Analysis for Unit 1 Undervoltage Protection Scheme" (22 pages follow)

Pagei F,rstEne!JlY CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. VENDOR CALCULATION NO.

8700-E-345 Rev. 1 N/A

[8J BV1 0 BV2 0 BV1/2 0 BV3 svswr I 0 DB I 0 PY Title/

Subject:

Voltage and Time Delay Analysis for Unit 1 Undervoltage Protection Scheme Category: [8J Active ID Historical ID Study Vendor Cale Summary: Yes D No [8J Classification: [8J Tier 1 Calculation [8J Safety-Related/Augmented Quality I Non-safety-Related Open Assumptions?: D Yes [8J No If Yes , Enter Tracking Number System Number: 36, 37 Functional Location : N/A Commitments: None Initiating Documents: CR-G203-2011-95145 (PY) Calculation Type:

(PY) Referenced In USAR Validation Database Yes D No I (PY) Referenced In Atlas? D Yes D No Computer Program(s)

Program Name Version / Revision Category Status Description ETAP 11 .1.0N B Active ETAP is used to perform various types of electrical power analyses . In this calculation, electrical load flow studies are performed to establish voltages at equipment and load centers under degraded voltage conditions .

Transient stability studies are used to determine whether motors can successfully start at reduced voltages.

EDISON 1.2.2 B Active EDISON is utilized for cable and raceway management and has voltage and cable ampacity analysis capabilities. In this calculation, inputs such as motor parameters and circuit impedances were obtained from the EDISON database .

Excel 2016 C Active Excel is a general-purpose spreadsheet program . In this calculation, Excel is used to tabulate results and perform mathematical computations .

Revision Record Originator Reviewer/Design Verifier Approver Rev. Affected Pages (Print, Sian & Date! (Print, Sian & Date! (Print, Sian & Date) 1 i through 15 Michael Berg Cory Murray Att. 1-3, 5-1 1, 13, and 16

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Description of Change: The method for calculating motor stall currents is modified . The maximum DVR time delay limit for accident conditions is reduced . New recommendations for overcurrent relay settings changes are provided. Refer to the Background/Objectives section for details .

Describe where the calculation will be evaluated for 10CFR50.59 and/or 10CFR72.48 applicability. 10CFR50.59 applicability is evaluated in the attached RAD and screen forms (17-01860).

Page ii F,rstE~ CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. VENDOR CALCULATION NO.

8700-E-345 Rev. 1 N/A Originator Reviewer/Design Verifier Approver Rev. Affected Pages (Print, Sian & Date) (Print, Sian & Date) (Print, Sian & Date) 0 All Michael Berg Cory Murray Robert Lubert 11/22/17 11/28/17 12/20/17 Description of Change: Initial issue.

Describe where the calculation will be evaluated for 10CFR50.59 and/or 10CFR72.48 applicability. 10CFR50.59 applicability was evaluated in the attached RAD and screen forms (17-01860) .

Page iii FtrstEneaiY CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. [] VENDOR CALC

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8700-E-345 Rev. 1 VENDOR CALCULATION NO.

TABLE OF CONTENTS SUBJECT PAGE COVERSHEET:

OBJECTIVE OR PURPOSE V SCOPE OF CALCULATION V

SUMMARY

OF RESULTS/CONCLUSIONS V LIMITATIONS OR RESTRICTION ON CALCULATION APPLICABILITY V IMPACT ON OUTPUT DOCUMENTS V DOCUMENT INDEX (DIN) vi CALCULATION COMPUTATION (BODY OF CALCULATION): 1 BACKGROUND/OBJECTIVE 1 DESIGN INPUTS 1 METHOD OF ANALYSIS 3 ASSUMPTIONS 10 ACCEPTANCE CRITERIA 11 COMPUTATION 12 RESULTS 13 CONCLUSIONS 13 RECOMMENDATIONS 14 ATTACHMENTS:

ATTACHMENT 1: Overcurrent Trip Times for Stall Conditions - 4160 Volt Buses 2 Pages ATTACHMENT 2: Overcurrent Trip Times for Stall Conditions - 480 Volt Unit Substations 2 Pages ATTACHMENT 3: Overcurrent Trip Times for Stall Conditions - 480 Volt Motor Control Centers 6 Pages ATTACHMENT 4: MCC Voltages That Preclude Motor Stalling 5 Pages ATTACHMENT 5: Load Flow - Normal with Degraded Voltage 32 Pages ATTACHMENT 6: Load Flow- Safety Injection (SI) with Degraded Voltage 34 Pages ATTACHMENT 7: Load Flow - Containment Isolation Phase B (CIB) with Degraded Voltage 20 Pages ATTACHMENT 8: Overcurrent Trip Times - Bus Supply Breakers (Normal, SI, CIB) 7 Pages ATTACHMENT 9: Motor Starting - Safety Injection (SI) with Degraded Voltage 299 Pages ATTACHMENT 10: Overcurrent Trip Times for Running Conditions -4160 Volt Buses 4 Pages ATTACHMENT 11 : Overcurrent Trip Times for Running Conditions - 480 Volt Unit Substations 2 Pages ATTACHMENT 12: Overcurrent Trip Times for Running Conditions - 480 Volt Motor Control Centers 4 Pages ATTACHMENT 13: Load Flow- Normal with Degraded Voltage -All 4160 Volt Motors Running 36 Pages ATTACHMENT 14: Load Diversity at 480 Volt Buses 70 Pages ATTACHMENT 15: Fuse Assessment for MCC Control Circuits 3 Pages ATTACHMENT 16: Overcurrent Relay Settings Changes 8 Pages

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8700-E-345 Rev. 1 VENDOR CALCULATION NO.

SUBJECT PAGE SUPPORTING DOCUMENTS (For Records Copy Only)

DESIGN VERIFICATION RECORD 1 Page CALCULATION REVIEW CHECKLIST 3 Pages 10CFR50.59 DOCUMENTATION 5 Pages 10CFR72.48 DOCUMENTATION N/A DESIGN INTERFACE

SUMMARY

8 Pages DESIGN INTERFACE EVALUATIONS N/A OTHER N/A TOTAL NUMBER OF PAGES IN CALCULATION (COVERSHEETS +BODY+ ATTACHMENTS) 573 Pages

Page v FtrstEne.!f1V CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. [] VENDOR CALC

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8700-E-345 Rev. 1 VENDOR CALCULATION NO.

OBJECTIVE OR PURPOSE:

For the Beaver Valley Unit 1 undervoltage protection scheme, this calculation establishes:

1. The analytical minimum voltage limit for the loss of voltage relays (L VRs) at the safety-related 4160 volt buses. The minimum voltage is selected to preclude normally running , safety-related motors from stalling during degraded voltage conditions.

2. The analytical maximum time delay limit for the degraded voltage relays (DVRs) during accident conditions. The maximum time delay is selected to preclude overcurrent protective devices from tripping during degraded voltage conditions .

Additionally, the calculation confirms the adequacy of the existing degraded voltage relay time delay for non-accident conditions .

SCOPE OF CALCULATION:

This calculation applies to safety-related loss of voltage and degraded voltage relays at Unit 1.

This calculation determines the analytical minimum voltage limit for the loss of voltage relays. Loss of voltage relays are provided for the safety-related 4160 volt buses and the safety-related 480 volt buses . However, Table 3.3.5-1 in the Technical Specifications addresses the 4160 volt buses only. The loss of voltage relays for the 480 volt buses are not addressed in this calculation .

For the degraded voltage relays , this calculation determines the analytical maximum time delay limit for accident scenarios and confirms the adequacy of the existing time delay for non-accident scenarios.

SUMMARY

OF RESULTS/CONCLUSIONS :

The analytical minimum voltage limit for the loss of voltage relays at the safety-related 4160 volt buses is 3141 volts (75.5%).

The analytical maximum time delay limit for the degraded voltage relays is 2.7 seconds for accident conditions. This limit may be increased to 4.4 seconds if certain overcurrent relay replacements and settings changes are implemented.

The existing degraded voltage relay time delay of 90 +/- 5.0 seconds is acceptable for non-accident conditions .

LIMITATIONS OR RESTRICTIONS ON CALCULATION APPLICABILITY:

The limits established in this calculation are contingent on settings changes for some overcurrent relays. Refer to the Recommendations section for details.

IMPACT ON OUTPUT DOCUMENTS:

Th is calculation establishes a new analytical maximum time delay limit for the degraded voltage relays during accident conditions . Calculation E-529 is the uncertainty calculation for the time delay relays. The calculation should be updated to incorporate the new analytical limit.

Revision O of this calculation established an analytical minimum voltage limit for the loss of voltage relays. The limit was incorporated into 8700-DEC-0212, the uncertainty calculation for the loss of voltage relays . The limit has not been changed; therefore, no updates to 8700-DEC-0212 are required.

Page vi FtrstEne!IlY CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. [ ] VENDOR CALC

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8700-E-345 Rev. 1 VENDOR CALCULATION NO.

DOCUMENT INDEX Q) ci u z C

5 :5

~ a. a.

z Document Number/Title Revision , Edition , Date ~ -C :5 0 Q) 0 0::

01 .010-0046 , Thermal Limit Curve for Auxiliary Feedwater Pump Motors Rev. A

~

01 .010-0096, Raw Water Pump Safe Operating and Accelerating Time Rev. A versus Current Curve

~

01 .015-0092 , 4 kV Normal and Emergency Switchgear Instruction Book Rev. AS ~

01.016-0097, Installation, Operation, and Maintenance for Valueline Rev. L ~

Control Center Mark I 02 .029-0030, Installation, Operation , and Maintenance for 25 APK-2 Low Rev. N ~

Head Safety Injection Pumps 1/2RCP-38A-PC, Calibration of ITE/ABB Single Phase Overcurrent Relays Rev. 8 ~

ITE Type 50 and ITE Type 51 (with SCR Outputs) 11700-ESK-115 Series Time-Current Coordination Diagrams (4160 Volt ~

Bus 1AE) 11700-ESK-116 Series Time-Current Coordination Diagrams (4160 Volt ~

Bus 1DF) 11700-ESK-128 Series Time-Current Coordination Diagrams (480 Volt ~

Buses 1N and 1N1) 11700-ESK-129 Series Time-Current Coordination Diagrams (480 Volt Buses 1P and 1P1)

~

12241-ESK-115L, Coordination Curve - 4160 V Bus 2AE, Bkr 2E12 , 600 Rev. 1 ~

HP Motor for Charging Pump High Head Safety lnj, 2CHS-P21A 1OST-36.3, Diesel Generator No. 1 Automatic Test Rev. 36 ~

1OST-36.4, Diesel Generator No. 2 Automatic Test Rev. 39 ~

1RCP-7-PC, Calibration of Westinghouse/ABB Overcurrent Relays, Type Rev. 6 ~

COM-5 8700-DEC-0212 , Beaver Valley Unit 1 4.16 kV Emergency Bus Rev. 0 ~

Undervoltage: Trip Feed and Start Diesel Uncertainty Calculations 8700-E-048, EOG Loading Analysis at Frequency above 60 Hz Rev. 5 ~

8700-E-068, Station Service Load Flow and Voltage Profile Analysis Rev. 5

~

8700-E-221 , 4160 and 480 Volt AC Load Management and Voltage Profile Rev. 2 and Rev. 1 Calculations Relating to Bus 1AE

~

8700-E-222 , 4160 and 480 Volt AC Load Management and Voltage Profile Rev. 1 and addenda Calculations Relating to Bus 1OF

~

8700-E-271 , Station Service System Dynamic Stability Study Rev. 3 Add . 3 ~

8700-RE-21 CE , Elementary Diagram - Diesel Generator 1 and 2 Auto Rev. 12 Loading Sequence

~

Beaver Valley Power Station Improved Standard Technical Specifications 7/29/2016 ~

Page vii FtrstEOO.!fiV CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.

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8700-E-345 Rev. 1 VENDOR CALCULATION NO.

Q) ci (.)

z C:

c..

z ~ c..  :,

0 Document Number/Title Revision , Edition , Date ~

Q) -C: 0 0::

Branch Technical Position 8-6, Adequacy of Station Electric Distribution Rev. 3 0 System Voltages Branch Technical Position PSB-1 , Adequacy of Station Electric Distribution Rev. 0 0 System Voltages BV1-VBE Series Electrical Protective Device Setting Sheets 0

BV1-VBF Series Electrical Protective Device Setting Sheets 0

Cutler-Hammer Curve No. SC-4139-87B May 2009 0

E-529, Beaver Valley Units 1 and 2, Degraded Voltage Relay (DVR) Time Rev. 0 0 Delay Relay Instrument Uncertainty ECP 11-0273, Unit 1 - Joint Owners Group Motor Operated Valve Periodic 0 Verification (JOG MOV PV) Program Implementation ECP 11-0296, Replace BV1 River Water Motor Operated Valves 0

ECP 11-0615, Replace Unit 1 "C" CCR Motor 0

ECP 13-0294, Replace Inside Recirc Spray 1RS-P-1B and 1RS-P-1A 0

Motors ECP 13-0355, Replace Unit 1 Safety-Related 480V MCC HFB Breakers 0

ECP 14-0791 , 1FP-C-5 Replacement Compressor and Condensing Unit 0

ECP 15-0298, NFPA 805 (IN92-18): Modify Valves and Actuators 0

Required for Operator Manual Operation Following a 'Hot Short" Event ES-E-004, Protective Relaying Philosophy for BVPS Unit No. 1 Rev. 7 0 Fundamentals of a Motor Thermal Model and Its Applications in Motor 2005 0 Protection by B. Venkataraman et al.

Industrial Power Systems Handbook by Donald Beeman First Edition , 1955 0 ML112130443, Beaver Valley Power Station - NRC Component Design 8/1/2011 0 Bases Inspection Report 05000334/2011007 and 05000412/20 11007 NEI 15-01 , An Analytical Approach for Establishing Degraded Voltage Rev. 0 0 Relay (DVR) Settings NEMA Condensed MG 1, Information Guide for General Purpose Industrial 2011 0

AC Small and Medium Squirrel-Cage Induction Motor Standards NRC Regulatory Issue Summary 2011 -12, Adequacy of Station Electric 12/29/2011 0 Distribution System Voltages Pl Database Accessed 7/13/2017 0

TER 007312 , Evaluate Replacement 40 HP Motor for VS-F-40B Rev. 0 0

Westinghouse Curve No. SC-340-70 January 1971 0

Page 1 ArstEOO!JlV CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO .: REVISION :

8700-E-345 1 Background/Objective For the Beaver Valley Unit 1 undervoltage protection scheme , this calculation establishes:

1. The analytical minimum voltage limit for the loss of voltage relays (LVRs) at the safety-related 4160 volt buses. The minimum voltage is selected to preclude normally running , safety-related motors from stalling during degraded voltage conditions.

2. The analytical maximum time delay limit for the degraded voltage relays (DVRs) during accident conditions. The maximum time delay is selected to preclude overcurrent protective devices from tripping during degraded voltage conditions.

Additionally, the calculation confirms the adequacy of the existing degraded voltage relay time delay for non-accident conditions.

The limits are intended to prevent overcurrent protection from operating before undervoltage protection during degraded voltage conditions . This ensures that safety-related equipment remains available to be transferred to the emergency diesel generators if the degraded voltage relays time out.

The limits support proposed modifications to the undervoltage protection scheme. The changes are being made to address an Unresolved Item (URI) identified during the 2011 NRC Component Design Basis Inspection (CDBI). For more information ,

refer to the associated inspection report (ML112130443).

Presently, the degraded voltage protection scheme utilizes a single 90 second time delay. The proposed scheme introduces a second , shorter time delay to be used during accident conditions. The shorter time delay ensures that safety-related equipment is transferred to the emergency diesel generators in time to support safety injection time delay assumptions used in the UFSAR accident analyses.

Revision 1 to this calculation modifies the method for calculating motor stall currents. Stall currents for starting motors are equal to 80 percent of the respective locked rotor currents. Previously, stall currents were calculated based on maximum motor torques. This approach is valid for motors that are running when a degraded voltage condition occurs ; however, for motors that are starting , it yields currents that are too low.

The change reduces the maximum DVR time delay limit for accident conditions . To permit a longer time delay to be used ,

overcurrent relay replacements and settings changes are recommended. The recommended settings include margin to address concerns that overcurrent relays may not reset before motors are transferred to the emergency diesel generators.

Additionally, the length of cable 1HVCBPL220 is corrected in the ETAP model. The cable supplies air handling unit 1VS-AC-1 B. It was identified that the cable length recorded in the EDISON database is unrealistically low.

Design Inputs

• Unless otherwise noted , motor parameters, such as rated horsepower, voltage , current, power factor, service facto r, torque , etc. were obtained from calculation 8700-E-221 Rev. 2, calculation 8700-E-222 Rev. 1 and its addenda , and the following unincorporated electrical calculation evaluation forms :

CEF ECP Bus Breaker Equipment Remark 1-11-005 ECP 11-0273 MCC-1-E04 D MOV-1RW-106B Motor replacement 1-11 -005 ECP 11-0273 MCC-1 -E04 p MOV-1RW-1 06A Motor replacement 1-11-005R1 ECP 11-0273 MCC-1-E08 z MOV-1RW-116B Motor replacement

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8700-E-345 1 CEF ECP Bus Breaker Equipment Remark 1-11-016R 1 ECP 11-0296 MCC-1-E02 D MOV-1RW-102B1 Motor replacement 1-11-016R1 ECP 11-0296 MCC-1-E04 C MOV-1RW-103D Motor replacement 1-11-018 ECP 11-0615 4KVS-1DF 1F1 1CC-P-1C Motor replacement 1-13-002 ECP 11-0296 MCC-1-E02 G MOV-1RW-102B2 Motor replacement 1-13-002 ECP 11-0296 MCC-1-E04 B MOV-1RW-103B Motor replacement 1-13-009 ECP 13-0355 MCC-1-E08 K MCC-1-E8-K Breaker replacement 1-13-011 ECP 13-0294 480VUS-1-9P 9P4 1RS-P-1B Motor replacement 1-15-005 ECP 14-0791 MCC-1-E08 y 1FP-C-5 Motor replacement 1-15-028 ECP 15-0298 MCC-1-E06 AU MOV-1 Sl-885B Motor replacement The maximum torque value for control room area return air fan 1VS-F-40B was obtained from TER 007312 .

• For equipment powered from motor control centers (MCCs), circuit impedances and electrical protective device information were obtained from calculation 8700-E-221 Rev. 2 , calculation 8700-E-222 Rev. 1 and its addenda, and the unincorporated electrical calculation evaluation forms identified above.

• Trip times for electrical protective devices were obtained from the applicable time-current coordination diagrams or vendor manuals. Specific references for each circuit or device model are identified in the calculation attachments.

• Setting tolerances for overcurrent relays were obtained from relay calibration procedures 1RCP-7-PC (for Westinghouse COM-5 relays) and 1/2RCP-38A-PC (for ITE 51 relays) .

• Equipment quality classifications (safety-related (Q) , augmented (A) , non-safety-related (N)) were obtained from the SAP database.

• Operating scenario information was obtained from the cable sizing calculation sheets in calculations 8700-E-221 Rev. 1 and 8700-E-222 Rev. 1.

• The load flow and transient stability studies documented in this calculation are based on a modified version of the ETAP model used in calculation 8700-E-068 Rev. 5.

• The length of cable 1HVCBPL220 is corrected in the ETAP model. The cable supplies air handling unit 1VS-AC-1 B.

It was identified that the cable length recorded in the EDISON database is unrealistically low. The new length (245 feet) is based on the original cable length (40 feet) , the length of conduit 1CL912PG (195 feet) , and 10 feet to account for transitions between raceways and equipment.

• Load diversity adjustments in the ETAP model are based on information in the Pl database and currents observed during field walkdowns. Additional information is available in Attachment 14.

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8700-E-345 1

• For motors that start from the emergency diesel generators during load steps 1 and 2, acceleration times are estimated based on the results of recent automatic load sequence tests . Relevant plots are included in Attachment 16.

• Automatic load sequence times for the emergency diesel generators are based on information in calculation 8700-E-048, setting sheets BV1-VBE-032 and BV1-VBF-031 , and elementary diagram 8700-RE-21 CE.

Method of Analysis The undervoltage protection scheme includes two levels of undervoltage protection-loss of voltage protection , which detects significant undervoltage conditions and operates after a short time delay, and degraded voltage protection , which detects less severe undervoltage conditions that can be tolerated for a longer period of time. The longer time delay of the degraded voltage relays allows voltages to recover following temporary transients (such as those caused by motor starting) and prevents unnecessary separation from the preferred power sources (i.e. the system station service transformers). The two levels of undervoltage protection work in conjunction to prevent damage to safety-related equipment.

The allowable values for the undervoltage protection settings are provided in Table 3.3.5-1 of the Technical Specifications.

The present limits are summarized in the following table :

Function Allowable Voltage Allowable Time Delay Loss of Voltage ~ 2962 V (71 .2% of4160 V) 1.0 +/- 0.1 seconds Degraded Voltage (4160 V) ~ 3885.4 V (93.4 % of 4160 V) 90 +/- 5.0 seconds Degraded Voltage (480 V) ~ 448 .3 V (93 .4% of 480 V) 90 +/- 5.0 seconds The present limits permit the bus voltages to drop to 2962 volts for up to 95 seconds before the buses are separated from the degraded power source. At this voltage, motors may stall. Stalled motors draw elevated currents which can cause electrical protective devices to operate . Motors that trip on overcurrent are not automatically loaded onto the emergency diesel generators and would not be immediately available to perform their accident mitigation functions. To prevent this from happening , this calculation establishes a new analytical minimum voltage limit for the loss of voltage relays .

A second , shorter degraded voltage relay time delay is being introduced for accident cond itions . This calculation establishes the corresponding analytical maximum time delay limit. The proposed changes are summarized in the following table :

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8700-E-345 1 Function Allowable Voltage Allowable Time Delay Loss of Voltage TBD 1.0 +/- 0.1 seconds Degraded Voltage (4160 V) ~ 3885.4 V (93.4% of 4160 V) 90 +/- 5.0 seconds without Safety Injection Signal Degraded Voltage (480 V) ~ 448.3 V (93.4% of 480 V) 90 +/- 5.0 seconds without Safety Injection Signal Degraded Voltage (4160 V) with ~ 3885.4 V (93.4% of4160 V) TBD Safety Injection Signal Degraded Voltage (480 V) with ~ 448.3 V (93.4% of 480 V) TBD Safety Injection Signal Minimum Voltage Limit for Loss of Voltage Relays (LVRs)

General Method Loss of voltage relays monitor the voltages at the safety-related 4160 volt buses . The minimum voltage limit for the loss of voltage relays should be high enough to preclude normally-running safety-related motors from stalling. The general method for determining the minimum voltage limit is as follows:

1. Establish the stall voltage for each motor.

2. For each motor control center, determine the minimum voltage that precludes downstream motors from stalling . (This step is necessary because the motors supplied from the motor control centers are not explicitly modeled in ETAP.

Rather, equipment powered from motor control centers is consolidated into lumped loads.) The results are screened to exclude non-safety-related motors, motors that are not normally running , and motors that run intermittently.

3. Determine the minimum voltage at each safety-related 4160 volt bus that yields adequate voltages at downstream motors and motor control centers . "Adequate voltages" are voltages that preclude motors from stalling .

1. Motor Stall Voltages The stall voltage of a running motor is given by Trat ed Vstall = -7:-- X Vra t ed max where Trated is the rated torque Tmax is the maximum (or breakdown) torque Vrated is the rated voltage For simplicity , motors powered from motor control centers are evaluated using the same torque value unless otherwise noted.

From NEMA MG 1, the breakdown torque of Design A and B, 60 hertz, single-speed , polyphase, squirrel cage, medium

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8700-E-345 1 motors is 200 percent minimum for motors rated 200 horsepower and less. A maximum torque of 200 percent corresponds to a stall voltage of 100%

Vstall =

Trated

-T,-- X Vrated max

= ZOO% X Vrated =0.7071 X Vrated Where the blanket 200 percent maximum torque value does not yield acceptable results , more accurate values are used. For example, the stall voltages for control room area return air fans 1VS-F-40A and 1VS-F-40B are calculated based on a maximum torque values of 228 percent and 216 percent, respectively.

2. Minimum Allowable Voltages at Motor Control Centers If the stall voltage of a motor is known , the corresponding voltage at the upstream power source can be calculated using the following formula:

Vsource = 3 X ( (~

1 pf +IR) 2

+ (:;;n 1 sin(cos- (pf)) +IX) 2

)

where pf is the motor power factor

/ is the adjusted motor current (see below)

R is the circuit resistance (includes cable, electrical protective device, and penetration resistances)

X is the circuit reactance (includes cable , electrical protective device, and penetration reactances)

The voltages in the preceding formula are line-to-line voltages .

For each motor powered from an MCC, the voltage at the MCC is calculated based on the motor stall voltage. For each MCC, the maximum of these voltages is the minimum allowable voltage-discounting non-safety-related equipment and equipment that is not normally running (e.g. motor operated valves and dampers). The most limiting motor for each MCC determines the minimum allowable voltage.

For running motors, motor current is approximately inversely proportional to the motor terminal voltage . At the stall voltage ,

the adjusted motor current is calculated as follows :

Sf X Ir1 I =- - x sf x 111 = -

V,-ated Vstall 0.7071 where sf is the rated service factor

/fl is the rated full load current For conservatism , the adjusted current takes into account the motor service factor.

3. Minimum Voltage Limit at Safety-Related 4160 Volt Buses Calculation 8700-E-068 Rev. 5 uses an ETAP model of the electrical distribution system to determine the voltages at equipment for various operating conditions. In this calculation , a mod ified version of that ETAP model is used to determine the voltages at the equipment given an undervoltage condition . The model is modified as follows :

• A fixed voltage source is connected to each of the safety-related 4160 volt buses .

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• To simplify reporting, equipment upstream of the safety-related 4160 volt buses is de-energized. (This does not influence the results at the safety-related equipment.)

• Negative lumped loads used to address load diversity are removed . Instead, the lumped loads connected to each motor control center are proportionally rescaled such that

1. The overall load at each of the 480 volt buses is greater than or comparable to the maximum load obtained from the Pl database.

2. The total current to each motor control center exceeds currents observed during field walkdowns whichever is most limiting. The same scaling factor is applied to all lumped loads unless otherwise noted. For determining the scaling factor, voltages at the 480 volt buses are set to closely match the results from study case J10 in 8700-E-068 Rev. 5. Additional details are available in Attachment 14.

The change yields more realistic voltage drops between the 480 volt buses and the motor control centers and addresses concerns about how the negative lumped loads behave at reduced voltages.

• Model parameters associated with 1RS-P-1B (full load current), 1VS-F-1A (full load current) , and 1VS-F-1B (full load power factor and locked rotor current) are adjusted to better match the available motor data.

• For 1VS-F-1A, 1VS-F-1B, and 1VS-F-1C, the percentage loading for the safety injection load category is reduced to match the percentage loading for the normal load category. The safety injection load had been set to the load that yields an overcurrent trip, which is not representative of expected load immediately following a safety injection.

Load flow study case J5A from calculation 8700-E-068 is reproduced with the modifications noted above. This study case corresponds to steady-state, maximum load conditions during normal operation . The load flow study is used to determine the voltages at motors and motor control centers. These voltages are compared to the motor stall voltages and the minimum allowable MCC voltages established in the previous steps. In the ETAP model , the voltages at the safety-related 4160 volt buses are iteratively adjusted to determine the minimum values that yield acceptable voltages at the downstream motors and motor control centers.

Maximum Time Delay Limit for Degraded Voltage Relays (DVRs)

Degraded voltage relays monitor the voltages at the safety-related 4160 volt buses and the safety-related 480 volt buses. For each train , the degraded voltage relays share a common time delay relay. The maximum time delay limit is selected to prevent motors from tripping on overcurrent before the degraded voltage relays time-out. This ensures that the equipment required to mitigate a design basis accident is available to be transferred to the emergency diesel generators.

Two degraded voltage scenarios are analyzed :

1. An accident scenario, in which motors automatically start in response to an accident signal. A shorter time delay is used in this scenario.

2. A non-accident scenario, in which motor starts are not considered . A longer time delay is used in this scenario.

In each scenario, motor currents are compared to the time-current characteristics of the respective overcurrent protective devices to determine how long it takes the devices to trip. Additionally, the total current associated with each bus is analyzed to confirm that bus supply breakers do not trip within the established time delay.

1. Accident Scenario This analysis primarily applies to motors that start in response to an accident signal (although other motors are included for information). Under degraded voltage conditions, motors that start in response to an accident signal are not guaranteed to have adequate voltage and are therefore assumed to stall. Stalled motors draw significantly more current than running motors, which results in the stalled motors tripping more quickly.

Motors start successfully provided that 80 percent of the rated voltage is available at the motor terminals. At lesser voltages, motors may stall. Because motor locked-rotor currents are proportional to voltage, 80 percent of the locked-rotor current is a good estimate for the maximum stall current:

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/stall = 0.8 X /LR where

/LR is the motor locked rotor current Once the stall currents are known , the minimum trip time for each motor may be determined by reviewing the time-current curve(s) for the applicable overcurrent protective device( s). This approach is used for motors powered directly from 4160 volt buses and 480 volt unit substations. The minimum of all the trip times (excluding non-safety-related equipment) is used to establish the maximum DVR time delay limit for accident conditions.

Rather than explicitly determine the trip time for each of the motors powered from the motor control centers , it is more efficient to confirm that the trip times are greater than a specific value. The following approach is used:

1. Establish the maximum DVR time delay limit for accident conditions .

2. Determine the breaker/overload heater model associated with each motor.

3. Using the time-current curves for each breaker/overload heater model, determine the minimum current that corresponds to a trip time equal to (or greater than) the maximum DVR time delay limit.

4. Compare the motor stall currents to the trip currents determined in the previous step. If the stall current is less than the trip current, the degraded voltage protection operates before the overcurrent protection. If this is not the case, setting changes should be considered.

This review excludes heaters, transformers, battery chargers, inverters, and other non-motor components . (Refer to the Assumptions section for information about why these components are excluded.) In some cases, non-safety-related motors are excluded if information necessary to determine the locked rotor currents is not readily available .

2. Non-accident Scenario This analysis primarily applies to motors that are normally running (although other motors are included for information). For running motors , the current is approximately inversely proportional to the motor terminal voltage.

For 4160 volt motors and motors directly powered from 480 volt unit substations, running currents at reduced voltage are determined using a load flow study case similar to the J5A study case described previously. The study case differs in that all 4160 volt motors are operating simultaneously. This allows the motor currents to be determined without running multiple study cases. Because the voltages at the 4160 volt buses are fixed , the calculated current for each motor is unaffected by how many 4160 volt motors are operating . (Running currents for 1RS-P-1 A, 1QS-P-1 A, 1RS-P-1 B, and 1QS-P-1 B-which are not normally running-are determined from study case J8F in Attachment 7.)

For motors powered from motor control centers , running currents at reduced voltage are the same as those used to determine the minimum allowable voltages at the motor control centers ; i.e.

Vr ated Sf X !fl I = - - x s f x 111 = - - -

Vstall 0.7071 For 4160 volt motors and motors directly powered from the 480 volt unit substations, the time-current coordination diagrams are reviewed to determine how long it takes the applicable overcurrent protective devices to trip at the maximum running currents . These times are compared to the maximum DVR time delay of 95 seconds for non-accident conditions.

For motors powered from motor control centers, the models of the associated overcurrent protective devices (overload heaters, molded case circuit breakers) are tabulated . For each model , the minimum current corresponding to a 95 second trip time is determined. These currents are compared to the maximum running current of each motor to determine if any devices trip in less than 95 seconds .

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8700-E-345 1 Confirm Bus Supply Breakers Do Not Trip Bus supply breakers may operate if many motors draw elevated currents simultaneously. Total bus currents are reviewed to determine whether bus supply breakers have the potential to trip. The maximum current at each bus varies depending on the operating scenario. The scenarios under consideration are summarized in the following table:

Bus Voltage Operating Scenario DVR Time Delay Remarks 4160 Volts Normal Max Non-accident Steady-state currents are elevated due to the degraded voltage condition. Motor starts are not considered.

480 Volts Normal Max Non-accident Steady-state currents are elevated due to the degraded voltage condition. Motor starts are not considered .

4160 Volts SI Max Accident Motors that automatically start in response to an SI signal are addressed. The following 4160 volt motors may automatically start: auxiliary feedwater, high-head safety injection, low-head safety injection, primary component cooling , and river water. An evaluation is performed to determine which motors may stall or take an extended time to start.

480 Volts SI Max Accident Motors that automatically start in response to an SI signal are addressed. Various motor-operated valves automatically start.

4160 Volts CIB Max Accident Motors that automatically start in response to a CIB signal are addressed. (Motors that start in response to an SI signal are considered to be running .) The outside recirculation spray pump motors start based on water level in the refueling water storage tank. The stub buses are automatically shed .

480 Volts CIB Max Accident Motors that automatically start in response to a CIB signal are addressed. (Motors that start in response to an SI signal are considered to be running .) The following 460 volt motors automatically start: inside recirculation spray, quench spray, and various motor-operated valves. The motor starts do not occur concurrently-quench spray starts after a five second time delay; inside recirculation spray starts based on water level in the refueling water storage tank. For the purpose of establishing the maximum bus currents, the inside recirculation spray pumps start, the quench spray pumps are already running , and the motor operated valves are not running (having already completed operation). The stub buses and pressurizer heaters are automatically shed .

A load flow study is performed for each operating scenario . For the normal operating scenario , bus currents are obtained from the same load flow study case used to determine the minimum voltage limit for the safety-related 4160 volt buses. For the safety injection (SI) and containment isolation phase B (CIB) operating scenarios, load flow study cases J7C and J8F from calculation 8700-E-068 Rev. 5 are reproduced with the modifications noted previously.

Page 9 FirstEOO.!J!V CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO .: REVISION :

8700-E-345 1 The load flow study cases do not address elevated currents caused by motors stalling . As necessary, currents are manually adjusted to account for stalled motors. (This is not necessary for the normal operating scenario, because the minimum voltage limit the safety-related 4160 volt buses is selected to preclude motors from stalling during normal operation .) Voltage results from the load flow studies are compared to previously established motor stall voltages and minimum required MCC voltages.

Running motors that do not have adequate voltages are considered to stall.

In the ETAP model, lumped loads connected to MCCs are segregated by load type (motor loads, MOVs, non-motor loads, etc.). As needed, load flow currents associated with the motor lumped loads are increased as described below to account for stall currents. No adjustments are made to the MOV lumped loads, because the MOV lumped loads already correspond to starting conditions.

Transient stability studies are used to determine whether starting motors have the potential to stall. For these study cases , the initial voltage at the safety-related 4160 volt buses is set to 100 percent, and a load impact event is used to reduce the bus voltages to the previously established minimum voltage limit. Motors are subsequently started . The transient stability results are reviewed to determine how long it takes motors to start. Motors that take an extended time to start (i.e. longer than the maximum DVR time delay limit for accident conditions) are considered to stall.

Total bus currents are determined using a bottom-up approach , starting with the motor control centers:

1. Motor Control Centers

a. For motor control centers that meet the previously established minimum voltage requirements, total bus currents are obtained directly from the ETAP load flow results.

b. For motor control centers that do not meet the minimum voltage requirements, total bus currents are adjusted as follows to account for stall currents:

2 VMee )

!Mee - [m otor + 6 X lmotor X ( 60 V 4

where

!M ee is the total MCC current obtained from the load flow results

!motor is the total motor current for the applicable MCC VMee is the voltage at the MCC Motor running currents are increased by a factor of six to approximate motor starting currents . A voltage adjustment factor is applied , because motor running currents are inversely proportional to the voltage while starting currents are proportional to the voltage. The adjustment is based on 460 volts, which is the rated voltage for most of the motors.

2. 480 Volt Unit Substations

a. Where motor voltages exceed the established stall voltages , motor currents are obtained directly from the ETAP load flow results.

b. Where motors are demonstrated to stall during starting , motor currents are set equal to previously established stall currents.

c. For running motors that stall , stall currents are calculated as follows :

Vmotor I

LR x- -

460 V where Vmotor is the voltage at the motor

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d. Currents for non-motor loads are obtained directly from the ETAP load flow results.

e. The total bus current is determined by summing the currents for the individual loads, including the total MCC currents established in the previous step.

3. 4160 Volt Buses

a. Where motor voltages exceed the established stall voltages, motor currents are obtained directly from the ETAP load flow results.

b. Where motors are demonstrated to stall during starting , motor currents are set equal to previously established stall currents.

c. For running motors that stall , stall currents are calculated as follows :

Vm ot or I x ---

LR 4160 V

d. The total bus current is determined by summing the currents for the individual loads, including the total 480 volt bus currents established in the previous step. Currents at 480 volts are converted to currents at 4160 volts by multiplying the currents by the transformer ratio of 480/4160.

For each bus , the total current is compared to the time-current curve(s) of the applicable electrical protective device(s) to determine how long it takes breakers to trip. These results are compared to the maximum DVR time delay limit to confirm that the degraded voltage protection operates before the overcurrent protection .

Overcurrent Relay Settings to Support Successful Emergency Diesel Generator Sequencing Overcurrent protection for most 4160 volt motors at Unit 1 is provided by electromechanical relays . Motors that start or stall during a degraded voltage condition may trip if they are subsequently sequenced onto an emergency diesel generator before the overcurrent re lays have time to reset. The primary motors of concern are those that start during Load Step 1 or 2, which occur O and 5 seconds into the load sequence, respectively.

Overcurrent relays for motors that start during subsequent load steps have at least 13.5 seconds to reset. (Load Step 3 occurs at 15 seconds +/- 10 percent.) Reset times for each overcurrent relay were obtained from completed calibration work orders. In all cases, the relays take less than 13.5 seconds to reset. The applicable work orders are listed in Attachment 16.

For load steps 1 and 2, motors can start successfully provided that the trip times of the overcurrent relays are greater than the sums of the degraded voltage relay time delay and the motor acceleration times ; i.e.

ttrip > t vvR + t start where ttrip is the minimum relay trip time, including tolerances t vvR is the maximum DVR time delay t start is the motor acceleration time when stated from the emergency diesel generator For motors that start during load steps 3 through 6, the trip times need only exceed the degraded voltage relay time delay.

Assumptions For motors rated 200 horsepower or less, the breakdown torque of safety-related motors is at least 200 percent of the full load torque . From NEMA MG 1, the breakdown torque of Design A and B, 60 hertz, single-speed , polyphase, squirrel cage, medium motors is 200 percent minimum for motors rated 200 horsepower and less.

Minimum required voltages at the motor control centers are calculated using the motor power factor at the rated voltage .

According to NEMA MG 1, a decrease in voltage generally yields an increase in power factor. Increasing the power factor

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8700-E-345 1 tends to increase the calculated voltage drop. Small changes in the calculated voltage drop due to power factor are considered to offset by other conservatisms in the calculation , such as using a maximum 200 percent torque for all MCC motors and calculating the voltage drop based on a 90°C conductor temperature .

This calculation does not address non-motor loads, such as heaters, battery chargers, and inverters. Temporary degraded voltage conditions are not expected to significantly affect heater function . The equipment that relies on battery chargers and inverters is backed-up by the station batteries. The temporary loss of a battery charger or inverter due to degraded voltage conditions is not expected to prevent other safety-related equipment from performing its design function .

For non-accident conditions , motor starts are not considered. In the absence of an accident signal , a motor that starts during degraded voltage conditions may stall and trip on overcurrent.

For groups of motors and other equipment powered from single MCC circuits , the trip times of electrical protective devices downstream of the MCC are not explicitly addressed . The trip times of downstream devices are assumed to be comparable to or greater than the trip times of devices at the MCCs. For this analysis, the trip times associated with 4160 volt equipment are most limiting.

Cascading motor stalls (i.e. one motor stalls which causes another motor to stall which causes another motor to stall. . .) are not credible. The calculation demonstrates that normally running , safety-related motors do not stall at the analytical minimum voltage limit for the loss of voltage relays. In general, if these motors stall, the bus voltage has decreased such that the loss of voltage relays will operate.

The rotor inertias for the recirculation spray pump motors (1 RS-P-1A, 1B, 2A, and 28) are not available. Because motor start times at reduced voltages could not readily be determined, bus trip times are calculated assuming that the motors stall during starting .

The documented maximum motor torque for control rod drive mechanism (CROM) fan 1VS-F-2C is 200 percent in specification BVS-358. This corresponds to the minimum required value for a NEMA Class B motor. It is probable that the specification data sheet was populated with the minimum required value in lieu of determining the actual maximum torque by calculation or test. The maximum motor torque value for similar fans 1VS-F-2A and 1VS-F-28 is 258 percent. For this calculation, it is assumed that the 1VS-F-2C motor torque is sufficient to prevent the motor from stalling when bus voltages are at the minimum analytical limit. The CROM fans are non-safety-related and are powered from the 480 volt stub buses.

Acceptance Criteria

1. For a degraded voltage condition without an accident signal , the loss of voltage relays shall drop out before normally running , safety-related motors stall. The minimum voltage limit at the safety-related 4160 volt buses is the minimum voltage that precludes normally running , safety-related motors from stalling during non-accident conditions .

2. For a degraded voltage condition coincident with an accident signal , the degraded voltage protection shall operate before the overcurrent protection . Assuming that motors stall during starting , the maximum OVR time delay shall be less than the operating time of the fastest overcurrent protective device. The maximum time delay criterion is based on the trip times of safety-related motors that start in response to an accident signal.

For accident conditions, the maximum OVR time delay shall be less than ten seconds-the maximum start time of the emergency diesel generators. This ensures that safety-related equipment is transferred to the emergency diesel generators in time to support safety injection time delay assumptions in the UFSAR accident analyses .

3. For a degraded voltage condition without an accident signal , the degraded voltage protection should operate before the overcurrent protection . Assuming that running motors do not stall , the maximum OVR time delay should be less than the operating time of the fastest overcurrent protective device. The maximum time delay criterion is based on the trip times of normally running , safety-related motors.

Regulatory Issue Summary 2011-12 states that "the [OVR] time delay chosen should be optimized to ensure that permanently connected Class 1 E loads are not damaged under sustained degraded voltage conditions (such as a sustained degraded voltage below the OVR voltage setting(s) for the duration of the time delay setting) ." Motors are provided with overcurrent protection to prevent thermal damage. If the degraded voltage protection is set to operate before the overcurrent protection , the selected time delays provide adequate protection against thermal damage.

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8700-E-345 1 Computation The computation is included in the following attachments:

• Attachment 1 shows the calculated stall voltage for each 4160 volt motor, the stall current at 80 percent voltage, and the corresponding trip time of the overcurrent protective device (with and without tolerances) . The minimum trip time for safety-related motors is used to establish the maximum DVR time delay limit for accident conditions .

• Attachment 2 shows the calculated stall voltage for each motor powered directly from a 480 volt unit substation , the stall current at 80 percent voltage, and the corresponding trip time of the overcurrent protective device (based on the lower end of the tolerance band) . The trip times for these motors are less limiting than the trip times for the 4160 volt motors.

• Attachment 3 shows the stall current at 80 percent voltage for each motor powered from an MCC , the associated overcurrent protective devices, and the minimum trip current corresponding to 6 seconds. The stall currents are compared to the trip currents to determine whether devices trip in less than 6 seconds. 6 seconds is used, because it envelopes the minimum trip times from attachments 1 and 2.

• For each motor powered from an MCC , Attachment 4 calculates the minimum MCC voltage that precludes the motor from stalling . A summary table shows the minimum voltage at each MCC that precludes normally running , safety-related motors from stalling .

• Attachment 5 is an ETAP load flow analysis report. The report shows the calculated voltage at each motor and motor control center given a fixed voltage at the safety-related 4160 volt buses. The results are compared to the stall voltages (attachments 1 and 2) and minimum required MCC voltages (Attachment 4) to establish the minimum voltage limit for the safety-related 4160 volt buses. The electrical alignment and loading correspond to normal operating conditions .

• Attachments 6 and 7 are ETAP load flow analysis reports that correspond to safety injection (SI) and containment isolation phase B (CIB) conditions, respectively. Voltages at the motors and motor control centers are calculated for the same 4160 volt bus voltage established in Attachment 5.

• Attachment 8 addresses the trip times of bus supply breakers for normal , SI , and CIB conditions . The total current to each bus and the associated breaker trip time are shown . These attachments utilize voltage and current information from the ETAP load flow analysis reports in attachments 5 through 7. Where appropriate , the load flow currents are adjusted to account for stalled motors.

• Attachment 9 addresses 4160 volt motors that automatically start in response to a safety injection signal. A transient stability study establishes whether the motors stall when started at reduced voltage. The results are used in Attachment 8 to determine whether load flow currents need to be adjusted .

• Attachments 10, 11 , and 12 are similar to the first three attachments but address running currents at reduced voltage rather than stall currents. The trip times of the corresponding electrical protective devices are used to confirm the adequacy of the existing degraded voltage relay time delay for non-accident conditions.

• Attachment 13 is similar to Attachment 5 but differs in that all 4160 volt motors are operating simultaneously. The results are used in attachments 10 and 11 to establish the running current of each motor.

• Attachment 14 contains information used to support load diversity adjustments to the ETAP model.

• Attachment 15 contains an assessment of fused MCC control circuits. Four safety-related MCC control circuits at Unit 1 are protected by fuses . The related motors do not automatically start in response to an accident signal.

• Attachment 16 includes proposed overcurrent relay settings changes. Some changes are necessary to ensure that emergency diesel generator sequencing is successful ; other changes are discretionary and support using a longer degraded voltage relay time delay.

Page 13 ArstEne.!J!Y CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

8700-E-345 1 Results Analytical Minimum Voltage Limit for the Loss of Voltage Relays For the safety-related 4160 volt buses, the voltage setting for the loss of voltage relays shall be greater than 3141 volts (75.5%). For normal operating conditions, this voltage precludes normally running safety-related motors from stalling .

Analytical Maximum Time Delay Limit for the Degraded Voltage Relays for Accident Conditions Based on present overcurrent relay settings , the degraded voltage relay time delay shall not exceed 2.7 seconds for accident conditions . The time delay is limited by the protective device settings for the outside recirculation spray pump motors. The trip times for safety-related 4160 volt motors range from 2.7 to 3.2 seconds; the trip times for low voltage motors are 4. 7 seconds or greater.

If overcurrent relay replacements and settings changes are implemented , degraded voltage relay time delays as high as 4.4 seconds can be supported. The maximum time delay is limited by the thermal capabilities of the auxiliary feedwater pump motors. Refer to the Recommendations section for details.

Bus trip times are 5.6 seconds or greater except for buses 1AE and 1DF, where the trip times are undefined. To prevent the bus supply breakers from tripping on overcurrent before the degraded voltage protection times out, relay settings changes are recommended. Refer to the Recommendations section for details.

4160 volt motors that start during a degraded voltage condition and immediately transfer to the emergency diesel generators may trip if the associated overcurrent relays do not have time to reset. The issue can be addressed by increasing the relay time dial settings. Refer to the Recommendations section for details.

Degraded Voltage Relay Time Delay for Non-Accident Conditions The degraded voltage relay time delay is 90 +/- 5.0 seconds for non-accident conditions. For steady-state , non-accident conditions , bus trip times are greater than 95 seconds. Most running , safety-related motors can ride-through a 95-second degraded voltage condition without tripping on overcurrent. Possible exceptions are 4160 volt motors for which overcurrent trip limes are undefined.

The safety-related 4160 volt motors are protected by Westinghouse COM-5 overcurrent relays . The applicable time-current curves are undefined for currents less than 150 percent of the relay pickup current. Considering relay calibration tolerances, motor currents can range from 100 to 112 percent of the relay pickup current during degraded voltage conditions. The primary equipment of concern is the charging pumps, the primary component cooling pumps , and the river water pumps , which are normally running .

Regulatory Issue Summary 2011-12 states that "the [DVR] lime delay chosen should be optimized to ensure that permanently connected Class 1E loads are not damaged under sustained degraded voltage conditions (such as a sustained degraded voltage below the DVR voltage setting(s) for the duration of the time delay setting) ." The degraded voltage relays lime out before the motor thermal limits are challenged . For accident conditions , the reduced degraded voltage relay time delay ensures that equipment is available to perform its accident mitigation function in time to support the UFSAR accident analyses.

For non-accident conditions , the existing 90 +/- 5.0 seconds prevents equipment damage due to prolonged operation at degraded voltages. The time delay is acceptable .

Conclusions The calculation concludes that:

1. The analytical minimum voltage limit for the loss of voltage relays at the safety-related 4160 volt buses is 3141 volts (75.5%).

2. The analytical maximum time delay limit for the degraded voltage relays is 2.7 seconds for accident conditions . This limit may be increased to 4.4 seconds if certain overcurrent relay replacements and settings changes are implemented .

3. The existing degraded voltage relay lime delay of 90 +/- 5.0 seconds is acceptable for non-accident conditions .

Page 14 FlrstEr1e5fV CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. : REVISION :

8700-E-345 1 These conclusions are contingent on implementing the recommendations in the following section.

Recommendations To support the conclusions, several overcurrent relay settings changes are recommended. The calculation results show that the supply breakers to buses 1AE and 1OF may trip on overcurrent for a safety injection coincident with a degraded voltage condition. The currents at buses 1AE and 1DF are monitored by overcurrent relays 67/51-VE107 and 67/51-VF107 , which are Westinghouse I RV-6 relays . The applicable time-current curves are undefined for currents less than 150 percent of the relay pickup current. At 150 percent of the pickup current, the relays are set to trip in approximately 2 seconds. The maximum calculated current is 1310.1 amps (at bus 1AE) . This corresponds to approximately 136 percent of the nominal pickup current of 960 amps . To minimize the risk of the breakers tripping during degraded voltage conditions , it is recommended that the relay pickup settings be increased. The pickup settings can be increased without adversely affecting relay coordination. The proposed settings changes are summarized in the following table.

Existing Pickup Proposed Pickup Bus Relay Setting Sheet Setting Setting 4KVS-1AE 67/51-VE107 4 (960 amps) 6 (1440 amps) BV1-VBE-007 4KVS-1DF 67/51-VF107 4 (960 amps) 6 (1440 amps) BV1-VBF-007 4160 volt motors that start during a degraded voltage condition and immediately transfer to the emergency diesel generators may trip if the associated overcurrent relays do not have time to reset. The issue can be addressed by increasing the relay time dial settings. This concern primarily applies to motors that sequence onto the emergency diesel generators during load steps 1 and 2. Affected equipment includes the charging pumps, outside recirculation spray pumps , primary component cooling pumps, and safety injection pumps.

Proposed settings changes are summarized in the following table. With these settings, motors that stall during degraded voltage conditions can subsequently start from the emergency diesel generators without tripping on overcurrent.

Existing Proposed Equipment Relay Checkpoint Time Checkpoint Time Setting Sheet (s) (s) 1CC-P-1C 51-VE101 2.6 6.0 BV1-VBE-001 1CC-P-1A 51-VE104 2.6 6.0 BV1-VBE-004 1SI-P-1A 51-VE108 2.6 5.5 BV1 -VBE-008 1CH-P-1A 51-VE111 2.7 5.3 BV1-VBE-015 1RS-P-2A 51-VE113 2.7 6.3 BV1-VBE-020 1CH-P-1C 51-VE115 2.7 5.3 BV1-VBE-022 1CC-P-1C 51 -VF101 2.6 6.0 BV1-VBF-001

Page 15 FlrstEoe!JlY CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

8700-E-345 1 Existing Proposed Equipment Relay Checkpoint Time Checkpoint Time Setting Sheet (s) (s) 1CC-P-1B 51-VF104 2.6 6.0 BV1-VBF-004 1SI-P-1 B 51-VF108 2.6 5.5 BV1-VBF-008 1CH-P-1B 51-VF111 2.7 5.3 BV1-VBF-015 1RS-P-2B 51-VF113 2.7 6.3 BV1 -VBF-020 1CH-P-1C 51 -VF115 2.7 5.3 BV1-VBF-022 The 2.?-second analytical limit for the degraded voltage relay time delay is low compared to typical limits at other nuclear power plants and provides little margin to set the relay. The maximum time delay is limited by overcurrent relay settings for the 4160 volt motors. Raising time dial settings and replacing certain overcurrent relays allows the limit to be increased. A limit as high as 4.4 seconds can be supported if the following setting changes are implemented.

Existing Proposed Equipment Relay Checkpoint Time Checkpoint Time Setting Sheet (s) (s) 1RH-P-1A 51-VE103 2.7 4.5 BV1 -VBE-003 1WR-P-1A 51 -VE110 2.6 4.2 BV1-VBE-014 1WR-P-1C 51-VE114 2.6 3.8 BV1-VBE-021 1FW-P-3A 51 -VE116 2.5 3.0 (COM-8) BV1-VBE-024 1RH-P-1B 51-VF103 2.7 4.1 BV1-VBF-003 1WR-P-1B 51-VF110 2.6 4.2 BV1-VBF-014 1WR-P-1C 51-VF114 2.6 3.8 BV1-VBF-021 1FW-P-3B 51-VF116 2.2 2.4 (COM-8) BV1 -VBF-023 To support a 4.4 second time delay, the overcurrent relays for the auxiliary feedwater pump motors should be replaced . One option is to replace the present Westinghouse/ABB COM-5 relays with COM-8 relays . The inverse characteristic of the COM-8 relays allows higher time dial settings to be used without compromising motor thermal protection . The checkpoint times in the preceding table are based on the replacement relays.

Enclosure B L-22-081 Calculation No. 8700-E-345, Revision 1, Addendum 1, "Voltage and Time Delay Analysis for Unit 1 Undervoltage Protection Scheme" (10 pages follow)

Page 1 of 10 energy CALCULATION ADDENDUM

--- harbor I

NOP-CC-3002-02 Rev. 08 CALCULATION NO.

8700-E-345

~ALCULATION REV. I ~DDENDUM NO.

[gl BV1 0 BV2 0 BV1/2 0 BV3 0 BVSWT I 0 DB I 0 PY TITLE/

SUBJECT:

(Must Match Original Calculation Title/ Subject)

Voltage and Time Delay Analysis for Unit 1 Undervoltage Protection Scheme D OAR Coversheet: D Addendum uses NOP-CC-3002 forms D Addendum uses Vendor's forms Classification: [gl Tier 1 Calculation I [gl Safety-Related/Augmented Quality I D Non-safety-Related Open Assumptions : D Yes [gl No If Yes , Enter Tracking Number Initiating Document(s): EER 601332122 Computer Program(s)

Program Name Version / Revision Category Status Description ETAP 20.0.4N B Active In this calculation addendum, ETAP is used to simulate reduced-voltage motor starts and create time-current coordination curves.

Objective or Purpose of Addendum :

Revision 1 of this calculation establishes the analytical maximum time delay for the Unit 1 degraded voltage re lays (DVRs) when a safety-injection signal is present. The time delay is chosen such that the degraded voltage protection operates before the overcurrent protection during degraded voltage conditions. To support a longer DVR time delay, the calculation recommended COM-5 overcurrent relays for the auxiliary feedwater pumps be replaced with COM-8 overcurrent relays . The inverse characteristic of the COM-8 relays allows higher time dial settings to be used while still maintaining adequate motor protection .

Due to difficulty procuring COM-8 relays , this addendum evaluates the use of COM-9 relays as an alternative . The COM-9 relays have a very-inverse characteristic that yields similar performance to the COM-8 relays .

Scope of Addendum :

This addendum applies to overcurrent relays 51-VE116 and 51-VF116. COM-9 relays are evaluated as replacements for the existing COM-5 relays . Recommended settings are provided .

Describe where the Addendum will be evaluated for Regulatory Applicability.

10CFR50.59 applicability was previously evaluated in RAD and screen forms 17-01860, which are attached to Revision 1 of the calculation . The previous evaluation still applies.

Prepared By (Print, Sign , and Date):

Michael Berg Digitally signed by Michael Berg Date: 2022.02 .28 15:48:53 Michael Berg

-05'00' Reviewed/ Verified By (Print, Sign , and Date): Digitally signed by John S .

John S. Flaherty, Jr. John S. Flaherty, Jr. Flaherty, Jr.

Date: 2022.02.28 16:14:32 -05'00' Approved By (Print, Sign , and Date): Digitally signed by Christopher Christopher Lord Christopher Lord Lord Date: 2022.03.03 15: 19:46 -05'00'

Page 2 of 10 energy CALCULATION ADDENDUM harbor NOP-CC-3002-02 Rev. 08 CALCULATION NO. CALCULATION REV. ADDENDUM NO.

8700-E-345 TABLE OF CONTENTS SUBJECT PAGE COVERSHEET .. ...... ... .. ................... ...... ......... ............. ...... ... ......... ......... ......... ... .. ... ....... .. .. ........ ..... .. .... .

TABLE OF CONTENTS ................. ................. ....... ........ .... .. .. ................. .. ...... .... .. ........................ ...... ... 2 DEPARTMENT INTERFACES ...... ............ .. ... ...... ........... ...... .................... .... .... ............... ..... .. .... ... ...... .. 2

SUMMARY

OF ADDENDUM :.......... ................. ....................... ............... ..... ..... .. .. .... ............... .............. . 2

SUMMARY

OF RESULTS/CONCLUSIONS OF ADDENDUM ......... .. ..... .............. .. ................. ...... .. .. . 2 LIMITATIONS OR RESTRICTIONS CREATED BY ADDENDUM ..... .. ......... .......... ........................... . 2 IMPACT OF ADDENDUM ON OUTPUT DOCUMENTS .. .......... ................ ... .. ... .... .. ........ ........ .. ........ . 3 DOCUMENT INDEX (DIN) ... ... ................. ....... .. ......... .......... ...... ........... ..... .... .............. ...... ....... ............ . 3 BODY OF CALCULATION : ....... ........... .............. ..... ... ........ .. ............ ...... .... ....... ............ ...... ...... ..... ... .... . 4 OBJECTIVE ..... .... .. ... ........ ... ........ ..... ... ... ..... .... ..... .. .... ............. .............. ... ............. ..... .. ................ ..... . 4 METHOD OF ANALYSIS .......... .. ...... ...... ..... ......... .. ....... .. .. ..... .. ................ .. .. .. ..... .. ... ............. ....... .. .. .. 4 ASSUMPTIONS ........ ........... ...... ............ ...................................... ....... ....... ...... ............ ... ................ ... . 5 ACCEPTANCE CRITERIA ..................... ... .... ......... ........... ....... .............. ............. ... ........ ......... .. .... .... .. 5 COMPUTATION ...... .. ......... ............ ........ ...... .... .... ......... .. ...... .. ..... ........ ....... .... ..... .... .. ........... ... .... ...... . 6 RESULTS AND CONCLUSIONS .... .. ......... .. .. .. ...... ...... .. .. .............. .... .. ...... ... ...... .. ......... .. ....... .. ... ...... . 10 ATTACHMENTS :

ATTACHMENT 1: Reduced-Voltage Motor Starting - Safety Injection at 75.5% Voltage .............. .. .. . 277 pages ATTACHMENT 2: Reduced-Voltage Motor Starting - Safety Injection at 80% Voltage ..................... . 277 pages ATTACHMENT 3: Development of 1FW-P-3A Motor Model 7 pages ATTACHMENT 4 : Time-Current Curves for COM Overcurrent Relay 4 pages TOTAL NUMBER OF PAGES IN ADDENDUM (Coversheets +Body+ Attachments) 575 pages SUPPORTING DOCUMENTS (For Records Copy Only)

DESIGN VERIFICATION RECORD ................. ....... ........... ..... ... .......... ... .... ..... ........ .. .. ........ ............. .. 1 page CALCULATION REVIEW CHECKLIST ........ .... ...... ..... .... ..... .... ... ... ............... .... .. ......... .. ........... ...... .... 3 pages DEPARTMENT INTERFACES Department Name of Person performing the Impact Review None N/A

SUMMARY

OF ADDENDUM

SUMMARY

OF RESULTS/CONCLUSIONS OF ADDENDUM:

COM-9 relays are an acceptable alternative to COM-8 relays . Refer to the calculation conclusions for recommended settings .

LIMITATIONS OR RESTRICTIONS CREATED BY ADDENDUM :

The addendum does not create any limitations or restrictions.

Page 3 of 10 energy CALCULATION ADDENDUM harbor NOP-CC-3002-02 Rev. 08 CALCULATION NO . CAL CU LATION REV. ADDENDUM NO.

8700-E-345 IMPACT OF ADDENDUM ON OUTPUT DOCUMENTS:

The addendum does not affect any output documents.

DOCUMENT INDEX (DIN)

Q)

()

C ci z ~ :5 z ~ :5 C.

Q) C. :5 0 Document Number/Title Revision, Edition, Date a:: .E: 0 01 .010-0046, Thermal Limit Curve for Auxiliary Feed Pump Motors Rev . A 0

1RCP-7-PC, Calibration of Westinghouse/ABB Overcurrent Relays, Type Rev. 6 0 0 COM-5 ABB Instruction Leaflet 41-102F, Type COM Overcurrent Relay September 1999 0 BV1-VBE-024, 4160 V Emergency Bus 1AE (Breaker 1E16) 1FW-P-3A, 400 Rev. 2 0 HP Steam Generator Auxiliary Feed Pump Motor Feeder BV1-VBF-023, 4160 V Emergency Bus 1DF (Breaker 1F16) 1FW-P-3B, 400 Rev . 3 0

HP Steam Generator Auxiliary Feed Pump Motor Feeder E-241, Transient Analysis for EDGs Rev. 1 0 ECP 18-0054, Implementation of Licensing AmendmenUSetting Changes for 0 the BV1 Degraded Voltage and Loss of Voltage Protection EER 601332122, COM-9 Relay to Replace COM-8 10/22/2021 0 0 ESK-115P, Coordination Curve for 4 160 V Emergency Bus 1AE, Breaker Rev. 1 0 1E16 ESK-116P, Coordination Curve for 4160 V Emergency Bus 1DF , Breaker Rev . 1 0 1F16 Protective Relaying : Principles and Applications by J. Lewis Blackbum Second Edition 0

Page 4 of 10 energy CALCULATION ADDENDUM harbor NOP-CC-3002-02 Rev. 08 CALCULATION NO. CALCULATION REV. ADDENDUM NO.

8700-E-345 Objective Revision 1 of this calculation establishes the analytical maximum time delay for the Unit 1 degraded voltage relays (DVRs) when a safety-injection signal is present. The time delay is chosen such that the degraded voltage protection operates before the overcurrent protection during degraded voltage conditions. To support a longer DVR t ime delay, the calculation recommended COM-5 overcurrent relays for the auxiliary feedwater pumps be replaced with COM-8 overcurrent relays. The inverse characteristic of the COM-8 relays allows higher time dial settings to be used while still maintaining adequate motor protection.

Due to difficulty procuring COM-8 relays, this addendum evaluates the use of COM-9 relays as an alternative .

The COM-9 relays have a very-inverse characteristic that yields similar performance to the COM-8 relays.

Method of Analysis The following relay settings were recommended in Revision 1 of the calculation. The proposed checkpoint times apply to the time-overcurrent elements. All other settings are unchanged. Each relay has a different checkpoint time because the setting sheets specify different test currents. However, the resultant relay performance is effectively identical.

Existing Proposed Coordination Equipment Relay Checkpoint Checkpoint Setting Sheet Diagram Time (s) Time (s) 1FW-P-3A 51-VE116 2.5 (COM-5) 3.0 (COM-8) BVl-VBE-024 ESK-115P lFW-P-3B 51-VF116 2.2 (COM-5) 2.4 (COM-8) BVl-VBF-023 ESK-116P Each checkpoint time corresponds to a test current on the respective relay setting sheet. During calibration, the test current is applied to the relay, and the relay is verified to trip within +/-5% ofthe checkpoint time . The trip time can be adjusted using the relay time dial. Details are available in relay calibration procedure lRCP-7-PC.

Time dial settings for the COM -9 relays are selected to closely match the performance of the COM-8 relays.

Based on the proposed checkpoint times, the minimum operating time of each relay is evaluated as follows :

1. The test current is obtained from the relay setting sheet.

2. The checkpoint time is adjusted to 95% of the selected value . This accounts for the -5% calibration tolerance.

3. The point formed by the test current and the adjusted checkpoint time is plotted .

4. The t ime-current characteristic curve of the overcurrent relay is plotted such that it intersects the point from the previous step.

5. The maximum motor stall current is obtained from Revision 1, Attachment 1 of the calculation.

6. Based on the maximum motor stall current, the operating time of the overcurrent relay is obtained from the time-current characteristic curve .

7. The operating time is verified to be greater than the analytical maximum time delay for the degraded voltage relays .

Page 5 of 10 energy CALCULATION ADDENDUM harbor NOP-CC-3002-02 Rev. 08 CALCULATION NO. CALCULATION REV. ADDENDUM NO.

8700-E-345 Steps 1 through 4 are repeated using a +5% tolerance to compare the maximum operating times of the overcurrent relays to the motor thermal limit curves. According to Protective Relaying: Principles and Applications by J. Lewis Blackburn, "The relays should operate just before the limits are reached or exceeded."

Reduced Voltage Motor Starting Reduced-voltage motor starts are analyzed in Revision 1, Attachment 9 of the calculation . The analysis demonstrates that the auxiliary feedwater pumps start successfully for bus voltages as low as 75.5%. Lesser voltages cause the loss-of-voltage relays to drop out and need not be analyzed. In EER 601332122, the analysis was reproduced for bus voltages of 75.5% and 80%. The results are incorporated into this calculation addendum. Motor starting curves are plotted for comparison to the relay curves.

The motor stall current from Revision 1 of the calculation is based on the locked rotor current from the motor data sheet (328 amps). However, the relay setting sheets indicate past measurements have been as high as 385 amps.

The ETAP induction motor model was developed using a combination of manufacturer data and test data in calculation E-241. An excerpt from the calculation, which discusses model development, is attached. The locked rotor current from the ETAP motor model is 384.7 amps, which is consistent with the test data. This provides assurance that the motor starting curves included in this calculation are representative of the actual motor performance.

Assumptions Motors are assumed to stall at 80% of rated voltage when starting. Maximum stall currents are estimated based on this assumption . Because the motors are specified to start successfully at 80% voltage and analysis demonstrates the motors start successfully at lesser voltages, this assumption is conservative.

The motor thermal limit curve for 1FW-P-3A on coordination diagram ESK-llSP is less restrictive than the curve for 1FW-P-3B on ESK-116P. The latter curve is consistent with the vendor-provided curve on drawing 01.010-0046. Since the motor thermal limit curve on ESK-116P is more restrictive and consistent with the vendor documentation, it is assumed to apply to both motors.

Acceptance Criteria For a degraded voltage condition coincident with a safety-injection signal, the degraded voltage protection shall operate before the overcurrent protection. The analytical maximum time delay for the Unit 1 degraded voltage relays is 4.4 seconds when a safety-injection signal is present. Assuming motors stall when starting, the operating times of the overcurrent relays shall be greater than 4.4 seconds.

The time-current characteristic curves of the overcurrent relays shall not intersect the motor thermal limit curves or the motor starting curves.

Page 6 of 10

~ energy CALCULATION ADDENDUM

_ harbor I I NOP-CC-3002-02 Rev. 08 CALCULATION NO. ~ALCULATION REV. ~DDENDUM NO.

8700-E-345 Computation To yield comparable performance to the COM -8 relays, the COM -9 relays need to be set to maximum time dial.

The maximum time dial setting is 11. The corresponding checkpoint times are:

Proposed Equipment Relay Checkpoint Time (s) 1FW-P-3A 51-VE116 2.83 (COM-9) lFW-P-38 51-VF116 2.17 (COM-9)

Relay 51-VE116 for Auxiliary Feedwater Pump 1FW-P-3A From setting sheet BVl-VBE-024, the test current is CT Ratio x Pickup Current x Checkpoint= Test Current 100 550%

5 X 3.5 A X l00% = 385 A The adjusted checkpoint time is 95%

lO0O/o X 2.83 S = 2.69 S The motor stall current is 262 amps (from Revision 1, Attachment 1 of the calculation).

Relay 51-VF116 for Auxiliary Feedwater Pump lFW-P-3B From setting sheet BVl-VBF-023, the test current is CT Ratio x Pickup Current x Checkpoint = Test Current 100 714%

5 X 3.5 A X --

100%

= 500 A The adjusted checkpoint time is 95%

1 0001/o X 2.17 S = 2.06 S The motor stall current is 262 amps (from Revision 1, Attachment 1 of the calculation) .

Coordination Diagrams Coordination diagrams are shown on the following pages. Each diagram is applicable to both trains.

Page 7 of 10

~ energy CALCULATION ADDENDUM

_ harbor NOP-CC-3002-02 Rev. 08 CALCULATION NO.

8700-E-345 I ~ALCULATION REV. I ~DDENDUM NO.

Two coordination diagrams are provided to improve readability. The first diagram identifies the minimum relay trip time and the minimum checkpoint times. The second diagram shows the motor starting characteristics.

Otherwise, the diagrams are identical.

The time dial setting is labeled as "Time Dial= 11 (-5%)" to reflect that the curve represents the maximum time dial with a -5% tolerance applied .

Page 8 of 10 energy CALCULATION ADDENDUM harbor NOP-CC-3002-02 Rev. 08 CALCULATION NO. CALCULATION REV. ADDENDUM NO.

8700-E-345 Amps X 10 (Plot Ref. kV=4 .1 6)

) 10 30 50 100 300 500 1K 101\

11( ,.....-,-,....,..,...--.,----..--......-~-...-....--_.-...,....-,--.-.--,-,.......---,.----,-,,.......- ,.-.....,_...,---,,---,--,*....--~ IK I

5(1(1 *\ 500

\

300

\

l 300 100

\ 100 so 50 30 - - - - - - - - - - Motor Thermal Limit 30 10 Maximum Relay Trip Time 10 5

VI

-0

~

Minimum Relay Trip Time CJ, (D

0 0

C:

1 262 A, 4.6 s ) 8

i Cl:> ~

Cl')

Minimum Checkpoint Time ------- Minimum Checkpoint Time VI 51 -VE116 51-VF 116 385A, 2.69 s 500 A, 2.06 s

~  :,

)

VE116 or 51 -VF116 Wes I mg house COM 9 CT Ratio 100 5 1TH Pickup ::. 3 5 (2

• 6 Sec - oA) l 1me l)1al = 11 ( *Mo) *J5 05 Inst - 25 (16 - 32 Sec 5A)

T11ne Oalay - 0 1 s

,JJ 13 ITI Inst= 27 (10 40 Soc

• 5A)

Time Delay - 0 01 s 01 ... - *- --- .£- .L..-.4 J-1.--1._

~,

5 3 5 10 JO SJ 100 JO-J 500 1K 1K 5'( 1 0K Amps X 10 (Plot Ref. kV=4 .16)

Page 9 of 10 energy CALCULATION ADDENDUM harbor NOP-CC-3002-02 Rev. 08 CALCULATION NO. CALCULATION REV. ADDENDUM NO.

8700-E-345 1 Amps X 10 (Plot Ref. kV:::4.16}

5 l s 10 JO 50 100 JOO 510 1K JK 5 10K 1K IK

\

soc

\ \ '500

\

I JOO 300 i

I

\

1(10

\'\ 100

\

\

~o \\ ~o I

3~

\.,*. 30 Motor Thermal Limit 1() -- - Maximum Relay Trip Time 10 r.11 5 5 Cl)

'C Motor Sta rting Motor Starting (>>

C: C, 0

u 80 % Bus Voltage 75.5% Bus Voltage 3 0

J Cl) ~

(./') (II 5

J-- - - - .S1-VE116 _or 5J-VF_11_6 Westinghouse COM-9 CT Rateo 100 5 1TH Pickup = 3 5 (2 6 Soc SA)

Time Dial = 11 (-5%)

05 Inst= 25 (16 - 32 Sec - SA) 05

• 11me Delay = 0 1 s OJ ITT 01 Inst - 27 (10 - 40 Sec - 5A)

T1111e Delay= 0 01 s

....J.l.........s-..1 .......__....__ _ ____.____.,___.__....._....___ _ _ ___.__ __.....,_, *JI 01 ...._.....1,JJ. 1- - . - _.._ ..1.

5 1  :; ],) 50 !00 3C*O 5.JO 1K 10K Amps X 10 (Plot Ref. kV=4 .16)

Page 10 of 10 energy CALCULATION ADDENDUM harbor NOP-CC-3002-02 Rev. 08 CALCULATION NO. CALCULATION REV. ADDENDUM NO.

8700-E-345 Results and Conclusions Results are summarized in the following table.

95% of Relay Test Current Motor Stall Greater than Relay Checkpoint Operating (A) Current (A) 4.4 s?

Time(s) Time (s) 51-VE116 385 2.69 262 4.6 Yes 51-VF116 500 2.06 262 4.6 Yes The minimum relay operating times are greater than 4.4 seconds assuming the motors stall when starting. The acceptance criterion is met. The attached motor starting analyses show the motors start successfully at lesser voltages, which provides additional assurance the overcurrent protection will not operate during degraded voltage conditions.

Adequate motor protection is provided for currents greater than approximately 90 amps. At lesser currents, the overcurrent relays may not operate before the motor thermal limits are exceeded. This is true for the existing relays as well as the proposed replacement relays. The restrictive thermal limits make it difficult to provide comprehensive motor protection while ensuring the auxiliary feedwater pumps remain available for all postulated accident scenarios. The pumps are normally on standby and operate infrequently. Sacrificing some degree of overload protection to ensure they remain available to perform their accident functions is an appropriate compromise.

COM-9 relays are an acceptable alternative to COM-8 relays . The following settings should be used for the time-overcurrent elements. All other settings are unchanged.

Checkpoint Checkpoint Setpoint Setpoint Relay Time(s) Current(%) Time (s) Current(%)

51-VE116 2.83 550 1.73 1000 51-VF116 2.17 714 1.73 1000

Enclosure C L-22-081 Calculation No. 10080-E-346, Revision 1, "Voltage and Time Delay Analysis for Unit 2 Undervoltage Protection Scheme" (24 pages follow)

Pagei FrrstEne.!J!Y CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. VENDOR CALCULATION NO.

10080-E-346 Rev. 1 NIA 0 BV1 [8J BV2 0 BV1/2 0 BV3 D BVSWT D DB I D PY Title/

Subject:

Voltage and Time Delay Analysis for Unit 2 Undervoltage Protection Scheme Category: 0 Active ID Historical ID Study Vendor Cale Summary: Yes D No 1:8J Classification: 0 Tier 1 Calculation 0 Safety-Related/Augmented Quality I Non-safety-Related Open Assumptions?: D Yes [8J No If Yes, Enter Tracking Number System Number: 36, 37 Functional Location : NIA Commitments: None Initiating Documents: CR-G203-2011-95145 (PY) Calculation Type:

(PY) Referenced In USAR Validation Database D Yes D No I (PY) Referenced In Atlas? D Yes D No Computer Program(s)

Program Name Version I Revision Category Status Description ETAP 1110N B Active ETAP is used to perform various types of electrical power analyses. In this calculation, electrical load flow studies are performed to establish voltages at equipment and load centers under degraded voltage conditions .

Transient stability studies are used to determine whether motors can successfully start at reduced voltages.

EDISON 1.2.2 B Active EDISON is utilized for cable and raceway management and has voltage and cable ampacity analysis capabilities. In this calculation, inputs such as motor parameters and circuit impedances were obtained from the EDISON database.

Excel 2016 C Active Excel is a general-purpose spreadsheet program . In this calculation , Excel is used to tabulate results and perform mathematical computations.

Revision Record Originator Reviewer/Design Verifier Approver Rev. Affected Pages (Print, Sian & Date) (Print, Sian & Date) {Print, Sian & Date) 1 i through 16 Cory Murray Michael Berg Robert Lubert .

~~ 4/s/1r1 ~C)'-1/~/*~ lfc$d'Lf </- S--N Att. 1, 3, and 9 Description of Change : The method for calculating motor stall currents is modified . New recommendations for overcurrent relay settings changes are provided . Refer to the Background/Objectives section for details.

Describe where the calculation will be evaluated for 10CFR50.59 and/or 10CFR72.48 applicability. 10CFR50.59 applicability is evaluated in the attached RAD and screen forms (17-03736).

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10080-E-346 Rev. 1 VENDOR CALCULATION NO.

Originator Reviewer/Design Verifier Approver Rev. Affected Pages (Print, Sian & Date) (Print, Sian & Date) (Print, Sian & Date) 0 All Cory Murray Michael Berg Robert Lubert 1/31/18 1/31/18 1/31/18 Description of Change : Initial issue.

Describe where the calculation will be evaluated for 10CFR50.59 and/or 10CFR72.48 applicability. 10CFR50.59 applicability is evaluated in the attached RAD and screen forms (17-03736).

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TABLE OF CONTENTS SUBJECT PAGE COVERSHEET:

OBJECTIVE OR PURPOSE V SCOPE OF CALCULATION V

SUMMARY

OF RESULTS/CONCLUSIONS V LIMITATIONS OR RESTRICTION ON CALCULATION APPLICABILITY V IMPACT ON OUTPUT DOCUMENTS V DOCUMENT INDEX (DIN) vi CALCULATION COMPUTATION (BODY OF CALCULATION): 1 BACKGROUND/OBJECTIVE 1 DESIGN INPUTS 1 METHOD OF ANALYSIS 4 ASSUMPTIONS 13 ACCEPTANCE CRITERIA 13 COMPUTATION 14 RESULTS 15 CONCLUSIONS 16 RECOMMENDATIONS 16 ATTACHMENTS:

ATTACHMENT 1: Overcurrent Trip Times for Stall Conditions - 4160 Volt Buses 2 Pages ATTACHMENT 2: Overcurrent Trip Times for Stall Conditions - 480 Volt Unit Substations 2 Pages ATTACHMENT 3: Overcurrent Trip Times for Stall Conditions - 480 Volt Motor Control Centers 7 Pages ATTACHMENT 4: MCC Voltages That Preclude Motor Stalling 7 Pages ATTACHMENT 5: Load Flow- Normal with Degraded Voltage 27 Pages ATTACHMENT 6: Load Flow- Safety Injection (SI) with Degraded Voltage 22 Pages ATTACHMENT 7: Load Flow - Containment Isolation Phase B (GIB) with Degraded Voltage 22 Pages ATTACHMENT 8: Load Flow- Containment Isolation Phase B (CIB+10 Mins) with Degraded Voltage 22 Pages ATTACHMENT 9: Overcurrent Trip Times - Bus Supply Breakers (Normal, SI , GIB, CIB+10 Mins) 5 Pages ATTACHMENT 10: Motor Starting - Safety Injection (SI) with Degraded Voltage 351 Pages ATTACHMENT 11 : Overcurrent Trip Times for Running Conditions - 4160 Volt Buses 3 Pages ATTACHMENT 12: Overcurrent Trip Times for Running Conditions - 480 Volt Unit Substations 2 Pages ATTACHMENT 13: Overcurrent Trip Times for Running Conditions - 480 Volt Motor Control Centers 5 Pages ATTACHMENT 14: Load Flow- Normal with Degraded Voltage -All 4160 Volt Motors Running 32 Pages ATTACHMENT 15: Evaluation of Fuses in Unit 2 MCC Control Circuits 6 Pages ATTACHMENT 16: Locked Off and Slave Contactor Motor Control Circuits Assessment 3 Pages

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SUBJECT PAGE SUPPORTING DOCUMENTS (For Records Copy Only)

DESIGN VERIFICATION RECORD 1 Page CALCULATION REVIEW CHECKLIST 3 Pages 10CFR50.59 DOCUMENTATION 6 Pages 10CFR72.48 DOCUMENTATION N/A DESIGN INTERFACE

SUMMARY

9 Pages DESIGN INTERFACE EVALUATIONS N/A OTHER N/A TOTAL NUMBER OF PAGES IN CALCULATION (COVERSHEETS +BODY+ ATTACHMENTS) 561 Pages

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OBJECTIVE OR PURPOSE:

For the Beaver Valley Unit 2 undervoltage protection scheme, this calculation establishes :

1. The analytical minimum voltage limit for the loss of voltage relays (L VRs) at the safety-related 4160 volt buses . The minimum voltage is selected to preclude normally running , safety-related motors from stalling during degraded voltage conditions.

2. The analytical maximum time delay limit for the degraded voltage relays (DVRs) during accident conditions. The maximum time delay is selected to preclude overcurrent protective devices from tripping during degraded voltage conditions.

Additionally, the calculation confirms the adequacy of the existing degraded voltage relay time delay for non-accident conditions.

SCOPE OF CALCULATION:

This calculation applies to safety-related loss of voltage and degraded voltage relays at Unit 2.

This calculation determines the analytical minimum voltage limit for the loss of voltage relays. Loss of voltage relays are provided for the safety-related 4160 volt buses and the safety-related 480 volt buses. However, Table 3.3.5-1 in the Technical Specifications addresses the 4160 volt buses only. The loss of voltage relays for the 480 volt buses are not addressed in this calculation.

For the degraded voltage relays, this calculation determines the analytical maximum time delay limit for accident scenarios and confirms the adequacy of the existing time delay for non-accident scenarios .

SUMMARY

OF RESULTS/CONCLUSIONS :

The analytical minimum voltage limit for the loss of voltage relays at the safety-related 4160 volt buses is 3230 volts (77 .65%)

at the 2AE bus and 3253 volts (78 .20%) at the 2DF bus.

The analytical maximum time delay limit for the degraded voltage relays is 4.7 seconds for accident conditions .

The existing degraded voltage relay time delay of 90 +/- 5.0 seconds is acceptable for non-accident conditions.

These conclusions are contingent upon implementing the overcurrent relay replacements and settings changes as documented in the Recommendations section .

LIMITATIONS OR RESTRICTIONS ON CALCULATION APPLICABILITY:

There are no limitations or restrictions on calculation applicability.

IMPACT ON OUTPUT DOCUMENTS:

This calculation establishes an analytical maximum time delay limit for the degraded voltage relays during accident conditions.

Calculation E-529 is the uncertainty calculation for the time delay relays, which incorporates this limit.

This calculation also establishes an analytical minimum voltage limit for the loss of voltage relays . Calculation 10080-DEC-0215 is the uncertainty calculation for the loss of voltage relays , which incorporates this limit.

Neither of these limits are affected by Revision 1 of this calculation ; therefore, no updates to E-529 or 10080-DEC-0215 are required .

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DOCUMENT INDEX Q)

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0 2501 .150-304-001 , 4kV Normal and Emergency Switchgear Instruction Rev. AK, 2/2/2017 [gJ Book 2602 .510-015-031 , Motor Data (Maximum Torque Values for the Rev. B, 9/23/1983 [gJ Recirculation Spray Pump Motors) 2501.160-310-001 , Instruction Manual for 480 Volt Motor Control Centers Rev. R, 5/16/2016 [gJ (Series 5600) 2701.100-010-036, Primary Component Cooling Pump Motor Test Data Rev. A, 11/16/1977 [gJ 1/2RCP-38A-PC, Calibration of ITE/ABB Single Phase Overcurrent Relays Rev. 8 [gJ ITE Type 50 and ITE Type 51 (with SCR Outputs) 1/2RCP-38B-PC, Calibration of ITE/ABB Three Phase Overcurrent Relays Rev. 8 [gJ Type 51 with SCR Outputs 12241-ESK-115 Series Time-Current Coordination Diagrams (4160 Volt [gJ Bus 2AE) 12241-ESK-116 Series Time-Current Coordination Diagrams (4160 Volt [gJ Bus 2DF) 12241-ESK-128 Series Time-Current Coordination Diagrams (480 Volt [gJ Bus 2N) 12241-ESK-129 Series Time-Current Coordination Diagrams (480 Volt [gJ Bus 2P) 10080-DEC-0215, Beaver Valley Unit 2 4.16 kV Emergency Bus Rev. 0 [gJ Undervoltage: Trip Feed and Start Diesel Uncertainty Calculations 10080-E-068, Station Service Load Flow and Voltage Profile Analysis Rev. 5 [gJ 10080-E-113, Maximum Control Circuit Lead Lengths for Class-1 E Motor Rev. 1, 3/1/2017 [gJ [gJ Control Centers 10080-E-221 , 4160 and 480 Volt AC Load Management and Voltage Rev. 0 and addenda [gJ Profile Calculations Relating to Bus 2AE 10080-E-222, 4160 and 480 Volt AC Load Management and Voltage Rev. 0 and addenda [gJ Profile Calculations Relating to Bus 2DF 10080-E-271 , BVPS Unit-2 Transient Stability Analysis Rev. 1 Add. 5 [gJ Beaver Valley Power Station Improved Standard Technical Specifications 7/29/2016 [gJ Branch Technical Position 8-6 , Adequacy of Station Electric Distribution Rev. 3 [gJ System Voltages Branch Technical Position PSB-1 , Adequacy of Station Electric Distribution Rev. O [gJ System Voltages E-529, Beaver Valley Units 1 and 2, Degraded Voltage Relay (DVR) Time Rev. 0 [gJ Delay Relay Instrument Uncertainty ECP 03-0587 , Replacement BV2 CROM Shroud Cooling Fan/Motor [gJ Assemblies

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ECP 04-0261 , Retire BV2 Hydrogen Recombiner D l:8:1 D ECP 05-0059, Replacement of BV2 Station Battery Chargers D l:8:1 D ECP 06-0211 , Replacement Main Steam Valve Area Recirculation Fans D l:8:1 D ECP 07-0002 , BV2 MCCB Replacement Project - 2008 D l:8:1 D ECP 08-0003 , BV2 MCCB Replacement Project - 2009 D l:8:1 D ECP 08-0062 , Replacement BV2 CROM Shroud Cooling Fan/Motor D l:8:1 D Assemblies ECP 08-0358, Replacement Motors for Intake Structure Supply Fans D l:8:1 D ECP 08-0359 , Replacement Motors for Emergency Switchgear Supply D l:8:1 D Fans ECP 08-0506 , BVPS-2 Install Sodium Tetraborate and Abandon Chemical D l:8:1 D Addition System ECP 10-0061 , Unit 2 - Joint Owners Group Motor Operated Valve Periodic D l:8:1 D Verification (JOG MOV PV) Program Implementation - 2R15 ECP 11-0083, Replace Unit 2 Containment Air Recirculation Fans and D l:8:1 D Vibration Monitors ECP 11-0618, Replace Unit 2 Service Water System MOV Butterfly Valves D l:8:1 D ECP 12-0290, Replace Failing 2EGA-C21B Motor D l:8:1 D ECP 12-0650, Replace Unit 2 EOG Fuel Transfer Pump Motors D l:8:1 D ECP 12-0699, Replace Unit 2 EOG Fuel Transfer Pump Motors D l:8:1 D ECP 14-0305, Repair LHSI Pump BV-2SIS-P21 B with New Impeller and D l:8:1 D Pump Casing Drain Modifications ECP 14-0606, Replace Diesel Generator Air Start Compressors D l:8:1 D ECP 15-0175, Replace Obsolete Hydrogen Monitoring Pump-Motor D l:8:1 D Assembly for BV-2HCS-P21A ECP 15-0299, NFPA 805 - Upgrade BV2 Motor Operated Valves to D l:8:1 D Protect Against Hot Shorts PERP 000444, BV-2HVZ-FN262A-MOTOR Replacement Motor D l:8:1 D Equivalency PERP 000544, BV-2HVZ-FN262B-MOTOR Replacement Motor D l:8:1 D Equivalency ES-E-003, Protective Relaying Philosophy for BVPS Unit No. 2 Rev. 4 l:8:1 D Fundamentals of a Motor Thermal Model and Its Applications in Motor 2005 l:8:1 Protection by B. Venkataraman et al.

Industrial Power Systems Handbook by Donald Beeman First Edition , 1955 l:8:1 ML112130443, Beaver Valley Power Station - NRC Component Design 8/1/2011 l:8:1 Bases Inspection Report 05000334/2011007 and 05000412/2011007

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NEI 15-01 , An Analytical Approach for Establishing Degraded Voltage Rev. 0 (8J Relay (DVR) Settings NEMA Condensed MG 1, Information Guide for General Purpose Industrial 2011 (8J AC Small and Medium Squirrel-Cage Induction Motor Standards NRC Regulatory Issue Summary 2011-12 , Adequacy of Station Electric 12/29/2011 (8J Distribution System Voltages 2OM-37 .5.B.7 , Table 37-7 480 V MCC Load List Rev. 43, 5/9/2017 (8J 2BVS-0179, Central Station Air Conditioning Units (Maximum Torque Rev. 0, Add. 1, (8J 8/26/1993 Values for the Control Room Air Conditioning Unit Motors)

E-0005DH , Elementary Diagram - 4160V Primary Component Cooling Rev. 16 (8J Pump 2CCP-P21A E-0005EH , Elementary Diagram - 4160V Primary Component Cooling Rev. 16 (8J Pump 2CCP-P21 B E-0005EG , Elementary Diagram - 4160V Primary Component Cooling Rev. 17 (8J Pump 2CCP-P21C E-0005DG , Elementary Diagram - 4160V Primary Component Cooling Rev. 18 (8J Pump 2CCP-P21C

Page 1 FlrslEneJriv CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. : REVISION :

10080-E-346 1 Background/Objective For the Beaver Valley Unit 2 undervoltage protection scheme, this calculation establishes:

1. The analytical minimum voltage limit for the loss of voltage relays (LVRs) at the safety-related 4160 volt buses. The minimum voltage is selected to preclude normally running , safety-related motors from stalling during degraded voltage conditions .

2. The analytical maximum time delay limit for the degraded voltage relays (DVRs) during accident conditions. The maximum time delay is selected to preclude overcurrent protective devices from tripping during degraded voltage conditions .

Additionally, the calculation confirms the adequacy of the existing degraded voltage relay time delay for non-accident conditions .

The limits are intended to prevent overcurrent protection from operating before undervoltage protection during degraded voltage conditions. This ensures that safety-related equipment remains available to be transferred to the emergency diesel generators if the degraded voltage relays time out.

The lim its support proposed modifications to the undervoltage protection scheme. The changes are being made to address an Unresolved Item (URI) identified during the 2011 NRC Component Design Basis Inspection (CDBI) . For more information ,

refer to the associated inspection report (ML112130443).

Presently, the degraded voltage protection scheme utilizes a single 90 second time delay. The proposed scheme introduces a second , shorter time delay to be used during accident conditions. The shorter time delay ensures that safety-related equipment is transferred to the emergency diesel generators in time to support safety injection time delay assumptions used in the UFSAR accident analyses.

Revision 1 to this calculation modifies the method for calculating motor stall currents for some motors. Stall currents for starting motors are equal to 80 percent of the respective locked rotor currents. Previously, stall currents were calculated based on maximum motor torques. This approach is valid for motors that are running when a degraded voltage condition occurs; however, for motors that start due to an SI or CIB signal , it yields currents that are too low.

The change does not reduce the maximum DVR time delay limit for accident conditions determined in Revision O of this calculation , provided that the recommended relay replacements and settings changes are implemented (refer to the Recommendations section) .

Design Inputs

• Unless otherwise noted, motor parameters, such as rated horsepower, voltage, current, power factor, service factor, torque, etc. were obtained from calculations 10080-E-221 Rev. 0 and calculation 10080-E-222 Rev. 0 and their addenda, and the following un incorporated electrical calculation evaluation forms:

CEF ECP Bus Breaker Equipment Remark 2-05-013 ECP 04-0261 MCC*2-E11 2F 2HCS*MOV120A Spared Breaker 2-05-013 ECP 04-0261 MCC*2-E11 SC 2HCS*MOV112A Spared Breaker 2-05-013 ECP 04-0261 MCC*2-E11 5D 2HCS*MOV113A Spared Breaker 2-05-013 ECP 04-0261 MCC*2-E11 9F 2HCS*H24A Spared Breaker 2-05-013 ECP 04-0261 480VUS-2-8N 7D 2JB1175 FOR Spared Breaker 2HCS*NBNR21A 2-07-001 ECP 07-0002 MCC*2-E07 2F 2HVD-FN222A Breaker Replacement 2-07-001 ECP 07-0002 MCC*2-E07 3A 2EGO-P23A Breaker Replacement 2-07-001 ECP 07-0002 MCC*2-E07 48 2EGS-P23A Breaker Replacement 2-07-001 ECP 07-0002 MCC*2-E07 6F 2EGS-H21A Breaker Replacement

Page 2 FlrstEnetflv CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

10080-E-346 1 CEF ECP Bus Breaker Equipment Remark 2-07-001 ECP 07-0002 MCC*2-E11 9D 2QSS-P24A Breaker Replacement (Superseded by 2-08-023) 2-07-001 ECP 07-0002 MCC*2-E13 4A 2HVZ-FN216A Breaker Replacement 2-07-003 ECP 05-0059 MCC*2-E05 1E BAT*CHG2-1 Charger Replacement 2-07-005 ECP 06-0211 480VUS*2-8N 10B 2HVR*FN206A Motor Replacement 2-08-004 ECP 08-0003 MCC*2-E05 7F 2SWS*MOV153-1 Breaker Reolacement 2-08-004 ECP 08-0003 MCC*2-E05 8F 2SWS*MOV154-1 Breaker Replacement 2-08-004 ECP 08-0003 MCC*2-E09 1F 2HVC*ACU201A Breaker Replacement 2-08-004 ECP 08-0003 MCC*2-E09 2D 2HVC*CH222A Breaker Replacement 2-08-004 ECP 08-0003 MCC*2-E09 3C 2HVC*MOD201 C Breaker Replacement 2-08-004 ECP 08-0003 MCC*2-E09 4A 2HVC*MOD201A Breaker Reolacement 2-08-004 ECP 08-0003 MCC*2-E11 10A 2HCS*MOV116 Breaker Replacement 2-08-004 ECP 08-0003 MCC*2-E13 1F 2HVR*ACU208A Breaker Replacement 2-08-004 ECP 08-0003 MCC*2-E15 1A 2HVP*ACUS301 Breaker Replacement 2-08-004 ECP 08-0003 MCC*2-E15 1D 2HVP*MOD301 Breaker Replacement 2-08-004 ECP 08-0003 MCC*2-E15 2E TRF*IRT-ASP Breaker Replacement 2-08-007-R1 ECP 08-0358 MCC*2-E01 2C 2HVW*FN257A Motor Replacement 2-08-015 ECP 08-0359 480VUS*2-8N 8C 2HVZ*FN261A Motor Replacement 2-08-023 ECP 08-0506 MCC*2-E11 9D 2QSS*P24 Spared Breaker (Supersedes 2-07-001) 2-08-023 ECP 08-0506 MCC*2-E11 4A 2QSS*MOV102A Soared Breaker 2-08-026-R1 ECP 08-0062 480VUS*2-8N 9B 2HVR*FN202A 1 Motor Replacement 2-10-001 ECP 10-0061 MCC*2-E11 8A 2RSS*MOV156C Motor Replacement 2-10-016 PERP-000444 480VUS*2-8N 8D 2HVZ-FN262A Motor Replacement 2-11-002 ECP 11-0083 480VUS*2-8N 11 B 2HVR*FN201 C Motor Replacement 2-12-013 ECP 12-0699 480VUS*2-8N 9C 2HVR-FN202B1 Motor Reolacement 2-12-007 ECP 11-0618 MCC*2-E01 1D 2SWS*MOV102A Motor Replacement 2-15-006 ECP11-0618 MCC*2-E03 2F 2SWS*MOV103A Motor Replacement 2-15-006 ECP11-0618 MCC*2-E03 7D 2SWE*MOV116A Motor Replacement 2-15-005 ECP 14-0606 MCC*2-E07 1B 2EGA-C21A Motor Replacement 2-15-005 ECP 14-0606 MCC*2-E07 1D 2EGA-C22A Motor Reolacement 2-15-012 ECP 15-0175 MCC*2-E07 4A 2HCS*HA100A Motor Replacement 2-04-002 ECP 03-0587 480VUS*2-9P 9B 2HVR*FN202A2 Motor Replacement 2-05-013 ECP 04-0261 MCC*2-E12 2F 2HCS*MOV120B Spared Breaker 2-05-013 ECP 04-0261 MCC*2-E12 5C 2HCS*MOV110B Spared Breaker 2-05-013 ECP 04-0261 MCC*2-E12 6A 2HCS*MOV113B Soared Breaker 2-05-013 ECP 04-0261 MCC*2-E12 6C 2HCS*MOV112B Spared Breaker 2-05-013 ECP 04-0261 MCC*2-E12 9C 2HCS*H24B Spared Breaker 2-05-013 ECP 04-0261 480VUS*2-9P 7D 2JB1176 FOR Spared Breaker 2HCS*NBNR21 B 2-07-001 ECP 07-0002 MCC*2-E04 5D 2CCP*MOV178-2 Pan Replacement 2-07-001 ECP 07-0002 MCC*2-E10 4A 2HVC*MOD201 B Pan Replacement 2-07-001 ECP 07-0002 MCC*2-E10 3C 2HVC*MOD201 D Pan Replacement 2-07-001 ECP 07-0002 MCC*2-E04 5A 2CCP*MOV177-2 Pan Replacement 2-07-001 ECP 07-0002 MCC*2-E10 1F 2HVC* ACU201 B Pan Replacement 2-07-001 ECP 07-0002 MCC*2-E04 3D 2CCP*MOV175-2 Pan Replacement 2-07-001 ECP 07-0002 MCC*2-E08 6F 2EGS*H21B Pan Replacement 2-07-003 ECP 05-0059 MCC*2-E06 1C BAT*CHG2-2 Charaer Reolacement 2-08-004 ECP 08-0003 MCC*2-E06 5F 2SWS*MOV152-2 Breaker Replacement 2-08-004 ECP 08-0003 MCC*2-E06 6F 2SWS*MOV153-2 Breaker Replacement 2-08-004 ECP 08-0003 MCC*2-E06 7F 2SWS*MOV154-2 Breaker Replacement

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10080-E-346 1 CEF ECP Bus Breaker Equipment Remark 2-08-004 ECP 08-0003 MCC*2-E06 8F 2SWS*MOV155-2 Breaker Replacement 2-08-004 ECP 08-0003 MCC*2-E12 10A 2HCS*MOV117 Breaker Reolacement 2-08-004 ECP 08-0003 MCC*2-E14 1F 2HVR*ACU2088 Breaker Replacement 2-08-007-R 1 ECP 08-0358 MCC*2-E02 2C 2HVW*FN2578 Motor Replacement 2-08-015 ECP 08-0359 480VUS*2-9P 8C 2HVZ*FN261 B Motor Replacement 2-08-023 ECP 08-0506 MCC*2-E12 3A 2QSS*MOV1028 Spared breaker 2-08-023 ECP 08-0506 MCC*2-E12 9A 2QSS*P248 Soared breaker 2-08-026-R1 ECP 08-0062 480VUS*2-9P 9C 2HVR-FN20282 Motor Replacement 2-11-002 ECP 11-0083 480VUS*2-9P 11 B 2HVR*FN201C Motor Replacement 2-11-005 PERP 000544 480VUS*2-9P 8D 2HVZ*FN2628 Motor Replacement 2-12-001 ECP 12-0290 MCC*2-E08 18 2EGA-C218 Motor Replacement (Superseded by 2-15-005) 2-12-010 ECP 12-0650 MCC*2-E08 2C 2EGF-P21D Motor Replacement 2-13-007 ECP 11-0618 MCC*2-E02 1F 2SWS*MOV1028 Motor Replacement 2-13-007 ECP11-0618 MCC*2-E02 2D 2SWS*MOV102C2 Motor Replacement 2-14-006 ECP 14-0305 4KVS*2DF 2F8 2SIS*P21B Impeller Replacement 2-15-005 ECP 14-0606 MCC*2-E08 18 2EGA-C21 B Motor Replacement (Supersedes 2-12-001) 2-15-005 ECP 14-0606 MCC*2-E08 1D 2EGA-C22B Motor Replacement 2-16-003 ECP 11-0618 MCC*2-E04 7C 2SWE*MOV1168 Motor Replacement 2-16-004 ECP 15-0299 MCC*2-E06 4A 2SIS*MOV867D Motor Replacement 2-16-004 ECP 15-0299 MCC*2-E12 7A 2RSS*MOV156D Motor Replacement

• For equipment powered from motor control centers (MCCs), circuit impedances and electrical protective device information were obtained from calculations 10080-E-221 Rev. 0 and calculation 10080-E-222 Rev. 0 and their addenda , and the unincorporated electrical calculation evaluation forms identified above.

• Trip times for electrical protective devices were obtained from the applicable time-current coordination diagrams or vendor manuals. Specific references for each circuit or device model are identified in the calculation attachments.

• Setting tolerances for ITE 51 overcurrent relays were obtained from relay calibration procedures 1/2RCP-38A-PC and 1/2RCP-38B-PC.

• Equipment quality classifications (safety-related (Q), augmented (A) , non-safety-related (N)) were obtained from the SAP database.

• Operating scenario information was obtained from the cable sizing calculation sheets in calculations 10080-E-221 Rev. 0 and 10080-E-222 Rev. 0.

• The load flow and transient stability studies documented in this calculation are based on a modified version of the ETAP model used in calculation 10080-E-068 Rev. 5.

• The maximum torque value for the recirculation spray pump motors (2RSS*P21A/B/C/D) was obtained from 2602.510-015-031 and the starting current for the component cooling pump motors (2CCP*P21 A/8/C) was obtained from 2701 .100-010-036.

Page 4 FlrstEne!J!V CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

10080-E-346 1 Method of Analysis The undervoltage protection scheme includes two levels of undervoltage protection-loss of voltage protection , which detects significant undervoltage conditions and operates after a short time delay, and degraded voltage protection , which detects less severe undervoltage conditions that can be tolerated for a longer period of time. The longer time delay of the degraded voltage relays allows voltages to recover following temporary transients (such as those caused by motor starting) and prevents unnecessary separation from the preferred power sources (i .e . the system station service transformers). The two levels of undervoltage protection work in conjunction to prevent damage to safety-related equipment.

The allowable values for the undervoltage protection settings are provided in Table 3.3.5-1 of the Technical Specifications.

The present limits are summarized in the following table:

Function Allowable Voltage Allowable Time Delay Loss of Voltage ~ 2962 V (71 .2% of 4160 V) 1.0 +/- 0.1 seconds Degraded Voltage (4160 V) ~ 3873 V (93.1% of4160 V) 90 +/- 5.0 seconds Degraded Voltage (480 V) ~ 446.9 V (93.1% of480 V) 90 +/- 5.0 seconds The present lim its permit the bus voltages to drop to 2962 volts for up to 95 seconds before the buses are separated from the degraded power source. At this voltage, motors may stall. Stalled motors draw elevated currents which can cause electrical protective devices to operate. Motors that trip on overcurrent are not automatically loaded onto the emergency diesel generators and would not be immediately available to perform their accident mitigation functions. To prevent this from happening, this calculation establishes a new analytical minimum voltage limit for the loss of voltage relays .

A second , shorter degraded voltage time delay is being introduced for accident conditions. This calculation establishes the corresponding analytical maximum time delay limit. The proposed changes are summarized in the following table :

Function Allowable Voltage Allowable Time Delay Loss of Voltage TBD 1.0 +/- 0.1 seconds Degraded Voltage (4160 V) ~ 3873 V (93 .1% of 4160 V) 90 +/- 5.0 seconds without Safety Injection Signal Degraded Voltage (480 V) ~ 446.9 V (93 .1% of 480 V) 90 +/- 5.0 seconds without Safety Injection Signal Degraded Voltage (4160 V) with ~ 3873 V (93.1% of4160 V) TBD Safety Injection Signal Degraded Voltage (480 V) with ~ 446.9 V (93 .1% of 480 V) TBD Safety Injection Signal

Page 5 FlrstEr1e!f!Y CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION :

10080-E-346 1 Minimum Voltage Limit for Loss of Voltage Relays {LVRs)

General Method Loss of voltage relays monitor the voltages at the safety-related 4160 volt buses . The minimum voltage limit for the loss of voltage relays should be high enough to preclude normally-running safety-related motors from stalling. The general method for determining the minimum voltage limit is as follows:

1. Establish the stall voltage for each motor.

2. For each motor control center, determine the minimum voltage that precludes downstream motors from stalling . (Th is step is necessary because the motors supplied from the motor control centers are not explicitly modeled in ETAP.

Rather, equipment powered from motor control centers is consolidated into lumped loads.) The results are screened to exclude non-safety-related motors, motors that are not normally running , and motors that run intermittently.

3. Determine the minimum voltage at each safety-related 4160 volt bus that yields adequate voltages at downstream motors and motor control centers. "Adequate voltages" are voltages that preclude motors from stalling .

1. Motor Stall Voltages The stall voltage of a running motor is given by Tr ated Vstall = -T,-- X Vra t ed m ax where Trated is the rated torque Tmax is the maximum (or breakdown) torque Vrated is the rated voltage For simplicity, motors powered from motor control centers are evaluated using the same torque value unless otherwise noted .

From NEMA MG 1, the breakdown torque of Design A and B, 60 hertz, single-speed , polyphase, squirrel cage, medium motors is 200 percent minimum for motors rated 200 horsepower and less. A maximum torque of 200 percent corresponds to a stall voltage of 100%

Vstall =

Tra t ed

-T,-- X Vrated m ax

= ZOO% X Vrated =0.7071 X Vrated Where the blanket 200 percent maximum torque value does not yield acceptable results , more accurate values are used. For example, the stall voltages for control room air conditioning units (2HVC*ACU201A/B) are calculated based on a maximum torque value of 216 percent.

2. Minimum Allowable Voltages at Motor Control Centers If the stall voltage of a motor is known , the corresponding voltage at the upstream power source can be calculated using the following formulas :

For 3-phase equipment or

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10080-E-346 1 Vsource = CCVstall Pf +2/R) 2 + (Vstausin(cos- 1 (pf)) +2/X) 2 ) For 1-phase equipment where pf is the motor power factor

/ is the adjusted motor current (see below)

R is the circuit resistance (includes cable, electrical protective device, and penetration resistances)

X is the circuit reactance (includes cable, electrical protective device, and penetration reactances)

The voltages in the preceding formula are line-to-line voltages .

For each motor powered from an MCC, the voltage at the MCC is calculated based on the motor stall voltage. For each MCC, the maximum of these voltages is the minimum allowable voltage-discounting non-safety-related equipment and equipment that is not normally running (e.g. motor operated valves and dampers). The most limiting motor for each MCC determines the minimum allowable voltage .

For running motors, motor current is approximately inversely proportional to the motor terminal voltage. At the stall voltage, the adjusted motor current is calculated as follows:

Vrated sf X 11 1 I =--xsf x /fl=---

Vstall 0.7071 where sf is the rated service factor 11 1 is the rated full load current For conservatism , the adjusted current takes into account the motor service factor.

3. Minimum Voltage Limit at Safety-Related 4160 Volt Buses Calculation 10080-E-068 Rev. 5 uses an ETAP model of the electrical distribution system to determine the voltages at equipment for various operating conditions. In this calculation , a modified version of that ETAP model is used to determine the voltages at the equipment given an undervoltage condition. The model is modified as follows :

• A fixed voltage source is connected to each of the safety-related 4160 volt buses .

• To simplify reporting , equipment upstream of the safety-related 4160 volt buses is de-energized. (This does not influence the results at the safety-related equipment.)

• Negative lumped loads used to address load diversity are removed . Instead, the lumped loads connected to each motor control center are proportionally rescaled to be 60% of each total load % (for each scenario) used in 10080-E-068 Rev. 5. 60% load diversity was chosen as a conservative estimate based on comparable rescaling used in Unit 1 calculation 8700-E-345 Rev. 0.

The change yields more realistic voltage drops between the 480 volt buses and the motor control centers and addresses concerns about how the negative lumped loads behave at reduced voltages. The changes to the motor control center lumped loads are summarized in the following table. The percentages shown are for all analyzed scenarios (Normal , SI , CIB , and CIB+10 Mins) unless otherwise noted.

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10080-E-346 1 MCC Lumped Load ID Original % Loading Used in 10080- New % Loading Used in 10080-E-E-068 Rev. 5 346 Rev. 0 MCC*2-E1Am 100% 60%

MCC*2-E1m 100% 60%

MCC*2-E2Am 100% 60%

MCC*2-E2m 100% 60%

MCC*2-E3Am 60% 36%

MCC*2-E3m 100% 60%

MCC*2-E4Am 60% 36%

MCC*2-E4m 100% 60%

MCC*2-E5Am 100% 60%

MCC*2-E5m 100% 60%

MCC*2-E6Am 100% 60%

MCC*2-E6m 100% 60%

MCC*2-E7m 102% Normal 61 % Normal 100% Other Scenarios 60% Other Scenarios MCC*2-E07s 100% Normal 60% Normal 0% Other Scenarios 0% Other Scenarios MCC*2-E8m 11 1% Normal 67% Normal 100% Other Scenarios 60% Other Scenarios MCC*2-E8s 100% Normal 60% Normal 0% Other Scenarios 0% Other Scenarios MCC*2-E9Am 100% 60%

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10080-E-346 1 MCC Lumped Load ID Original % Loading Used in 10080- New % Loading Used in 10080-E-E-068 Rev. 5 346 Rev. 0 MCC*2-E9m 114% CIB/CIB+10 Mins 69% CIB/CIB+10 Mins 100% Other Scenarios 60% Other Scenarios MCC*2-E9s 100% CIB/CIB+10 Mins 60% CIB/CIB+10 Mins 0% Other Scenarios 0% Other Scenarios MCC*2-E10Am 100% 60%

MCC*2-E10m 114% CIB/CIB+10 Mins 69% CIB/CIB+10 Mins 100% Other Scenarios 60% Other Scenarios MCC*2-E10s 100% CIB+10 Mins 60% CIB+10 Mins 0% Other Scenarios 0% Other Scenarios MCC*2-E11Am 100% 60%

MCC*2-E11m 100% 60%

MCC*2-E12Am 100% 60%

MCC*2-E12m 100% 60%

MCC*2-E13Am 100% 60%

MCC*2-E13m 100% 60%

MCC*2-E14Am 100% 60%

MCC*2-E14m 100% 60%

MCC*2-E15Am 100% 60%

MCC*2-E15m 100% 60%

Load flow study case LFANXC4 from calculation 10080-E-068 is reproduced with the modifications noted above. This study case corresponds to steady-state, maximum load conditions during normal operation . The load flow study is used to determine the voltages at motors and motor control centers. These voltages are compared to the motor stall voltages and the minimum allowable MCC voltages established in the previous steps. In the ETAP model , the voltages at the safety-related

Page 9 FlrstErle!F[Y CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION :

10080-E-346 1 4160 volt buses are iteratively adjusted to determine the minimum values that yield acceptable voltages at the downstream motors and motor control centers.

Maximum Time Delay Limit for Degraded Voltage Relays (DVRs)

Degraded voltage relays monitor the voltages at the safety-related 4160 volt buses and the safety-related 480 volt buses. For each train , the degraded voltage relays share a common time delay relay. The maximum time delay limit is selected to prevent motors from tripping on overcurrent before the degraded voltage relays time-out. This ensures that the equipment required to mitigate a design basis accident is available to be transferred to the emergency diesel generators.

Two degraded voltage scenarios are analyzed :

1. An accident scenario , in which motors automatically start in response to an accident signal. A shorter time delay is used in this scenario.

2. A non-accident scenario, in which motor starts are not considered. A longer time delay is used in this scenario.

In each scenario, motor currents are compared to the time-current characteristics of the respective overcurrent protective devices to determine how long it takes the devices to trip. Additionally, the total current associated with each bus is analyzed to confirm that bus supply breakers do not trip within the established time delay.

1. Accident Scenario This analysis primarily applies to motors that start in response to an accident signal (although other motors are included for information). Under degraded voltage conditions , motors that start in response to an accident signal are not guaranteed to have adequate voltage and are therefore assumed to stall . Stalled motors draw significantly more current than running motors, which results in the stalled motors tripping more quickly.

Motors start successfully provided that 80 percent of the rated voltage is available at the motor terminals. At lesser voltages, motors may stall . Because motor locked-rotor currents are proportional to voltage , 80 percent of the locked-rotor current is a good estimate for the maximum stall current:

!stall = 0.8 x /LR where

/LR is the motor locked rotor current Stall currents for running motors may be calculated as follows:

Vstall

/sta ll = -V-- X /LR rated For simplicity and conservatism , the starting stall method is used for all motors powered from motor control centers.

Once the stall currents are known, the minimum trip time for each motor may be determined by reviewing the time-current curve(s) for the applicable overcurrent protective device(s). This approach is used for motors powered directly from 4160 volt buses and 480 volt unit substations. The minimum of all the trip times (excluding non-safety-related equipment) is used to establish the maximum DVR time delay limit for accident conditions .

Rather than explicitly determine the trip time for each of the motors powered from the motor control centers , it is more efficient to confirm that the trip times are greater than a specific value. The following approach is used:

1. Establish the maximum DVR time delay limit for accident conditions .

2. Determine the breaker/overload heater model associated with each motor.

3. Using the time-current curves for each breaker/overload heater model , determine the minimum current that corresponds to a trip time equal to (or greater than) the maximum DVR time delay limit.

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10080-E-346 1

4. Compare the motor stall currents to the trip currents determined in the previous step . If the stall current is less than the trip current, the degraded voltage protection operates before the overcurrent protection. If this is not the case ,

setting changes should be considered .

This review excludes heaters, transformers , battery chargers, inverters, and other non-motor components. (Refer to the Assumptions section for information about why these components are excluded.) In some cases, non-safety-related motors are excluded if information necessary to determine the locked rotor currents is not readily available .

2. Non-accident Scenario This analysis primarily applies to motors that are normally running (although other motors are included for information). For running motors, the current is approximately inversely proportional to the motor terminal voltage.

For 4160 volt motors and motors directly powered from 480 volt unit substations , running currents at reduced voltage are determined using a load flow study case similar to the LFANXC4 study case described previously. The study case differs in that all 4160 volt motors are operating simultaneously. This allows the motor currents to be determined without running multiple study cases . Because the voltages at the 4160 volt buses are fixed , the calculated current for each motor is unaffected by how many 4160 volt motors are operating. (Running currents for 2RSS*P21A/B/C/D and 2QSS*P21A/B-which are not normally running-are determined from study case LFANXC4ALL in Attachment 14.)

For motors powered from motor control centers , running currents at reduced voltage are the same as those used to determine the minimum allowable voltages at the motor control centers; i.e.

sf X Ir1 Vrat ed I = - - x s f x /11 =-~-

Vstau 0.7071 For 4160 volt motors and motors directly powered from the 480 volt unit substations, the time-current coordination diagrams are reviewed to determine how long it takes the applicable overcurrent protective devices to trip at the maximum running currents. These times are compared to the maximum degraded voltage relay time delay of 95 seconds for non-accident conditions .

For motors powered from motor control centers , the models of the associated overcurrent protective devices (overload heaters, molded case circuit breakers) are tabulated . For each model , the minimum current corresponding to a 95 second trip time is determined. These currents are compared to the maximum running current of each motor to determine if any devices trip in less than 95 seconds.

Confirm Bus Supply Breakers Do Not Trip Bus supply breakers may operate if many motors draw elevated currents simultaneously. Total bus currents are reviewed to determine whether bus supply breakers have the potential to trip. The maximum current at each bus varies depending on the operating scenario. The scenarios under consideration are summarized in the following table:

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10080-E-346 1 Bus Voltage Operating Scenario DVR Time Delay Remarks 4160 Volts Normal Max Non-accident Steady-state currents are elevated due to the degraded voltage condition . Motor starts are not considered .

480 Volts Normal Max Non-accident Steady-state currents are elevated due to the degraded voltage condition. Motor starts are not considered.

4160 Volts SI Max Accident Motors that automatically start in response to an SI signal are addressed. The following 4160 volt motors may automatically start: auxiliary feedwater, high-head safety injection , low-head safety injection, and service water. An evaluation is performed to determine which motors may stall or take an extended time to start.

480 Volts SI Max Accident Motors that automatically start in response to an SI signal are addressed. Various motor-operated valves automatically start. The pressurizer heaters, CROM fans ,

and CAR fans are automatically shed .

4160 Volts CIB Max Accident The quench spray motors automatically start in response to a CIB signal. (Motors that start in response to an SI signal are considered to be running.)

480 Volts CIB Max Accident Motors that automatically start in response to a CIB signal are addressed . (Motors that start in response to an SI signal are considered to be running.) Various motor-operated valves automatically start.

4160 Volts CIB+10 Minutes Max Accident Motors that automatically start some time after a CIB signal are addressed. (Motors that start in response to an SI and CIB signal are considered to be running.) The inside recirculation spray and outside recirculation spray motors automatically start based on water level in the refueling water storage tank. For the purpose of establishing the maximum bus currents, the inside and outside recirculation spray pumps start, and the quench spray pumps are already running .

480 Volts CIB+10 Minutes Max Accident Motors that automatically start some time after a CIB signal are addressed . (Motors that start in response to an SI and CIB signal are considered to be running .) No 480 volt motors start for this scenario.

A load flow study is performed for each operating scenario. For the normal operating scenario , bus currents are obtained from the same load flow study case used to determine the minimum voltage limit for the safety-related 4160 volt buses. For the safety injection (SI), containment isolation phase B (CIB) , and containment isolation phase B + 10 minutes (CIB+10) operating scenarios, load flow study cases LVASXC4, LFACXC4, and LVACXC4 from calculation 10080-E-068 Rev. 5 are reproduced with the modifications noted previously.

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10080-E-346 1 The load flow study cases do not address elevated currents caused by motors stalling . As necessary, currents are manually adjusted to account for stalled motors. (This is not necessary for the normal operating scenario, because the minimum voltage limit the safety-related 4160 volt buses is selected to preclude motors from stalling during normal operation .) Voltage results from the load flow studies are compared to previously established motor stall voltages and minimum required MCC voltages .

Running motors that do not have adequate voltages are considered to stall.

In the ETAP model, lumped loads connected to MCCs are segregated by load type (motor loads, MOVs, non-motor loads, etc.). As needed, load flow currents associated with the motor lumped loads are increased as described below to account for stall currents. No adjustments are made to the MOV lumped loads, because the MOV lumped loads already correspond to starting conditions.

Transient stability studies are used to determine whether starting motors have the potential to stall . For these study cases, the initial voltage at the safety-related 4160 volt buses is set to 100 percent, and a load impact event is used to reduce the bus voltages to the previously established minimum voltage limit. Motors are subsequently started . The transient stability results are reviewed to determine how long it takes motors to start. Motors that take an extended time to start (i. e. longer than the maximum DVR time delay limit for accident conditions) are considered to stall.

Total bus currents are determined using a bottom-up approach , starting with the motor control centers:

1. Motor Control Centers

a. For motor control centers that meet the previously established minimum voltage requirements , total bus currents are obtained directly from the ETAP load flow results.

b. For motor control centers that do not meet the minimum voltage requirements, total bus currents are adjusted as follows to account for stall currents:

2 VMee )

!Mee - !motor + 6 X /motor X ( 460 V where

/Mee is the total MCC current obtained from the load flow results

!motor is the total motor current for the applicable MCC VMee is the voltage at the MCC Motor running currents are increased by a factor of six to approximate motor starting currents . A voltage adjustment factor is applied , because motor running currents are inversely proportional to the voltage while starting currents are proportional to the voltage. The adjustment is based on 460 volts, which is the rated voltage for most of the motors.

2. 480 Volt Unit Substations

a. Where motor voltages exceed the established stall voltages , motor currents are obtained directly from the ETAP load flow results.

b. Where motor voltages do not exceed the stall voltages or motors are demonstrated to stall during starting ,

motor currents are set equal to previously established stall currents.

c. Currents for non-motor loads are obtained directly from the ETAP load flow results.

d. The total bus current is determined by summing the currents for the individual loads, including the total MCC currents established in the previous step .

3. 4160 Volt Buses

a. Where motor voltages exceed the established stall voltages , motor currents are obtained directly from the ETAP load flow results.

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10080-E-346 1

b. Where motor voltages do not exceed the stall voltages or motors are demonstrated to stall during starting ,

motor currents are set equal to previously established stall currents.

c. The total bus current is determined by summing the currents for the individual loads, including the total 480 volt bus currents established in the previous step. Currents at 480 volts are converted to currents at 4160 volts by multiplying the currents by the transformer ratio of 480/4160.

For each bus , the total current is compared to the time-current curve(s) of the applicable electrical protective device(s) to determine how long it takes breakers to trip. These results are compared to the maximum DVR time delay limit to confirm that the degraded voltage protection operates before the overcurrent protection.

Confirm Overcurrent Relays Do Not Operate During Emergency Diesel Generator Sequencing Overcurrent protection for 4160 volt motors at Unit 2 is provided by solid-state relays; this type of relay resets almost instantaneously. Overcurrent relays are therefore expected to reset before motors are sequenced onto the emergency diesel generators (EDGs). There is little risk of tripping motors when they are sequenced onto the EDGs. This is a concern at Unit 1 because overcurrent protection for most 4160 volt motors at Unit 1 is provided by electromechanical relays . Refer to Calculation 8700-E-345 Rev. 1 for more information.

Assumptions For motors rated 200 horsepower or less, the breakdown torque of safety-related motors is at least 200 percent of the full load torque. From NEMA MG 1, the breakdown torque of Design A and B, 60 hertz, single-speed, polyphase, squirrel cage ,

medium motors is 200 percent minimum for motors rated 200 horsepower and less.

Minimum required voltages at the motor control centers are calculated using the motor power factor at the rated voltage.

According to NEMA MG 1, a decrease in voltage generally yields an increase in power factor. Increasing the power factor tends to increase the calculated voltage drop. Small changes in the calculated voltage drop due to power factor are considered to offset by other conservatisms in the calculation , such as using a maximum 200 percent torque for all MCC motors and calculating the voltage drop based on a 90°C conductor temperature.

This calculation does not address non-motor loads, such as heaters, battery chargers , and inverters. Temporary degraded voltage conditions are not expected to significantly affect heater function . The equipment that relies on battery chargers and inverters is backed-up by the station batteries. The temporary loss of a battery charger or inverter due to degraded voltage conditions is not expected to prevent other safety-related equipment from performing its design function.

For non-accident conditions , motor starts are not considered . In the absence of an accident signal, a motor that starts during degraded voltage conditions may stall and trip on overcurrent.

For groups of motors and other equipment powered from single MCC circuits, the trip times of electrical protective devices downstream of the MCC are not explicitly addressed . The trip times of downstream devices are assumed to be comparable to or greater than the trip times of devices at the MCCs. For this analysis , the trip times associated with 4160 volt equipment are most limiting.

Cascading motor stalls (i .e. one motor stalls which causes another motor to stall which causes another motor to stall. . .) are not credible. The calculation demonstrates that normally running, safety-related motors do not stall at the analytical minimum voltage limit for the loss of voltage relays. In general , if these motors stall , the bus voltage has decreased such that the loss of voltage relays will operate .

Acceptance Criteria

1. For a degraded voltage condition without an accident signal , the loss of voltage relays shall drop out before normally running, safety-related motors stall. The minimum voltage limit at the safety-related 4160 volt buses is the minimum voltage that precludes normally running , safety-related motors from stalling during non-accident conditions.

2. For a degraded voltage condition coincident with an accident signal , the degraded voltage protection shall operate before the overcurrent protection . Assuming that motors stall during starting , the maximum degraded voltage relay time delay shall be less than the operating time of the fastest overcurrent protective device. The maximum time delay criterion is based on the trip times of safety-related motors that start in response to an accident signal.

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10080-E-346 1 For accident conditions, the maximum degraded voltage relay time delay shall be less than ten seconds-the maximum start time of the emergency diesel generators. This ensures that safety-related equipment is transferred to the emergency diesel generators in time to support safety injection time delay assumptions in the UFSAR accident analyses.

3. For a degraded voltage condition without an accident signal , the degraded voltage protection should operate before the overcurrent protection . Assuming that running motors do not stall , the maximum degraded voltage relay time delay should be less than the operating time of the fastest overcurrent protective device. The maximum time delay criterion is based on the trip times of normally running , safety-related motors.

Regulatory Issue Summary 2011-12 states that "the [DVR] time delay chosen should be optimized to ensure that permanently connected Class 1 E loads are not damaged under sustained degraded voltage conditions (such as a sustained degraded voltage below the DVR voltage setting(s) for the duration of the time delay setting)." Motors are provided with overcurrent protection to prevent thermal damage. If the degraded voltage protection is set to operate before the overcurrent protection, the selected time delays provide adequate protection against thermal damage.

Computation The computation is included in the following attachments:

• Attachment 1 shows the calculated stall voltage for each 4160 volt motor, the corresponding stall current, and the trip time of the overcurrent protective device (with and without tolerances) . The minimum trip time for safety-related motors is used to establish the maximum DVR time delay limit for accident conditions.

• Attachment 2 shows the calculated stall voltage for each motor powered directly from a 480 volt unit substation , the corresponding stall current, and the trip time of the overcurrent protective device (based on the lower end of the tolerance band) . The trip times for these motors are less limiting than the trip times for the 4160 volt motors.

• Attachment 3 shows the stall current at 80 percent voltage for each motor powered from an MCC, the associated overcurrent protective devices, and the minimum trip current corresponding to 6 seconds . The stall currents are compared to the trip currents to determine whether devices trip in less than 6 seconds. 6 seconds is used, because it envelopes the minimum trip times from attachments 1 and 2.

• For each motor powered from an MCC, Attachment 4 calculates the minimum MCC voltage that precludes the motor from stalling . A summary table shows the minimum voltage at each MCC that precludes normally running, safety-related motors from stalling .

• Attachment 5 is an ETAP load flow analysis report. The report shows the calculated voltage at each motor and motor control center given a fixed voltage at the safety-related 4160 volt buses. The results are compared to the stall voltages (attachments 1 and 2) and minimum required MCC voltages (Attachment 4) to establish the minimum voltage limit for the safety-related 4160 volt buses . The electrical alignment and loading correspond to normal operating conditions .

• Attachments 6, 7, and 8 are ETAP load flow analysis reports that correspond to safety injection (SI), containment isolation phase B (CIB), and CIB+10 minutes conditions , respectively. Voltages at the motors and motor control centers are calculated for the same 4160 volt bus voltage established in Attachment 5.

• Attachment 9 addresses the trip times of bus supply breakers for normal, SI , CIB , and CIB+10 minutes conditions.

The total current to each bus and the associated breaker trip time are shown . These attachments utilize voltage and current information from the ETAP load flow analysis reports in attachments 5 through 8. Where appropriate, the load flow currents are adjusted to account for stalled motors.

• Attachment 10 addresses 4160 volt motors that automatically start in response to a safety injection signal. A transient stability study establishes whether the motors stall when started at reduced voltage. The results are used in Attachment 9 to determine whether load flow currents need to be adjusted .

• Attachments 11 , 12, and 13 are similar to the first three attachments but address running currents at reduced voltage rather than stall currents. The trip times of the corresponding electrical protective devices are used to confirm the adequacy of the existing degraded voltage relay time delay for non-accident conditions .

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10080-E-346 1

• Attachment 14 is similar to Attachment 5 but differs in that all 4160 volt motors are operating simultaneously. The results are used in attachments 11 and 12 to establish the running current of each motor.

• Attachment 15 contains an assessment of fuses in MCC control circuits. Section 2.3.1 of NEI 15-01 Rev. 1 recommends that control circuits powered from safety-related motor control centers be evaluated for accident-initiated motors to ensure their control circuit fuses do not blow if the starters do not have sufficient voltage to pick up during the degraded voltage timeout period .

• Attachment 16 contains an assessment of MCC control circuits that have a Normal Service Arrangement (NSA) of locked off, retired in place , or utilize slave contactors. The related motors do not automatically start in response to an accident signal. Therefore, this equipment is not evaluated in this calculation.

Results Analytical Minimum Voltage Limit for the Loss of Voltage Relays For the safety-related 4160 volt buses , the voltage setting for the loss of voltage relays shall be greater than 3230 volts (77.65%) at the 2AE bus and 3253 volts (78.20%) at the 2DF bus. For normal operating conditions, these voltages preclude normally running safety-related motors from stalling.

Analytical Maximum Time Delay Limit for the Degraded Voltage Relays for Accident Conditions For accident conditions, the degraded voltage relay time delay shall not exceed 4. 7 seconds (provided the recommended overcurrent relay replacements and settings changes are implemented). The time delay is limited by the protective device settings for the service water pumps (2SWS*P2 1A/B/C). For stall conditions , the trip times for 4160 volt motors range from 3.9 to 7.2 seconds (after the recommended overcurrent relay replacements and settings changes are implemented); the trip times for low voltage motors are 5.8 seconds or greater.

For stall conditions, the minimum value of 3.9 seconds was not selected because ii corresponds to the trip times of the component cooling pumps (CCPs). The CCPs are normally running ; the minimum analytical limit for the loss of voltage relays precludes normally running safety-related motors from stalling . The CCPs do not start in response to an SI signal and automatically trip during a CIB . The CCPs would only have the potential to stall when starting during a degraded voltage condition. Since they would either be already running or off during normal conditions , and do not start in response to an SI signal , the risk of tripping a CCP during degraded voltage conditions is minimal.

All bus trip times are >4.7 seconds except for buses 2AE and 2DF, where the trip times are undefined for some scenarios.

Even in the undefined region of the time-current curves, ii is evident that all bus trip times are >4.7 seconds . Bus supply breakers will not trip during degraded voltage conditions.

Degraded Voltage Relay Time Delay for Non-Accident Conditions The degraded voltage relay time delay is 90 +/- 5.0 seconds for non-accident conditions. For steady-state , non-accident conditions, bus trip times are greater than 95 seconds. Most running , safety-related motors can ride-through a 95-second degraded voltage condition without tripping on overcurrent. Possible exceptions are 4160 volt motors for which overcurrent trip times are undefined.

The safety-related 4160 volt motors are protected by ITE 51 L overcurrent relays. The applicable time-current curves are undefined for currents less than 150 percent of the relay pickup current. Considering relay calibration tolerances , motor currents can range from 100 to 116 percent of the relay pickup current during degraded voltage conditions. The primary equipment of concern is the primary component cooling pumps and the service water pumps, which are normally running.

Although the overcurrent trip times are undefined for this equipment, it is apparent that they would be > 95 seconds based on extrapolation of the time-current curves .

Regulatory Issue Summary 2011-12 states that "the [DVR] time delay chosen should be optimized to ensure that permanently connected Class 1 E loads are not damaged under sustained degraded voltage conditions (such as a sustained degraded voltage below the DVR voltage setting(s) for the duration of the time delay setting) ." The degraded voltage relays time out before the motor thermal limits are challenged . For accident conditions , the reduced degraded voltage relay time delay ensures that equipment is available to perform its accident mitigation function in time to support the UFSAR accident analyses.

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10080-E-346 1 For non-accident conditions , the existing 90 +/- 5.0 seconds prevents equipment damage due to prolonged operation at degraded voltages . The time delay is acceptable.

Conclusions The calculation concludes that:

1. The analytical minimum voltage limit for the loss of voltage relays at the safety-related 4160 volt buses is 3230 volts (77.65%) at the 2AE bus and 3253 volts (78.20%) at the 2DF bus.

2. The analytical maximum time delay limit for the degraded voltage relays is 4.7 seconds for accident conditions .

3. The existing degraded voltage relay time delay of 90 +/- 5.0 seconds is acceptable for non-accident conditions.

These conclusions are contingent on implementing the recommendations in the following section.

Recommendations To support the conclusions , several overcurrent relay settings changes are required .

The maximum time delay is limited by overcurrent relay settings for the 4160 volt motors. Raising time dial settings and replacing certain overcurrent relays allows the limit to be increased. A limit of 4.7 seconds can be supported when the following setting changes are implemented.

Existing Proposed Equipment Relay Checkpoint Time Checkpoint Time Setting Sheet (s) (s) 2SWS*P21A 51-VE214 2.3 2.4 BV2-VBE-011 2SWS*P21C 51-VE216 2.3 2.4 BV2-VBE-019 2FWE*P23A 51 -VE218 1.55 4.2 (51M) BV2-VBE-020 2SWS*P21B 51-VF214 2.3 2.4 BV2-VBF-011 2SWS*P21C 51-VF216 2.3 2.4 BV2-VBF-019 2FWE*P23B 51-VF218 1.55 4.2 (51M) BV2-VBF-020 To support the 4.7 second time delay, the overcurrent relays for the auxiliary feedwater pump motors shall be replaced . The present ITE 51 L relays should be replaced with ITE 51 M relays. The inverse characteristic of the 51 M relays allows higher time dial settings to be used without compromising motor thermal protection. The checkpoint times in the preceding table are based on the replacement relays.

Enclosure D L-22-081 Calculation No. 10080-E-346, Revision 1, Addendum 1, "Voltage and Time Delay Analysis for Unit 2 Undervoltage Protection Scheme" (9 pages follow)

Page 1 of 9 energy CALCULATION ADDENDUM

.- harbor I I NOP-CC-3002-02 Rev. 08 CALCULATION NO. ~ALCULATION REV. ~DDENDUM NO.

10080-E-346 0 BV1 ~ BV2 0 BV1/2 0 BV3 0 BVSWT I 0 DB I 0 PY TITLE/

SUBJECT:

(Must Match Original Calculation Title/Subject)

Voltage and Time Delay Analysis for Unit 2 Undervoltage Protection Scheme D OAR Coversheet: D Addendum uses NOP-CC-3002 forms D Addendum uses Vendor's forms Classification: ~ Tier 1 Calculation I ~ Safety-Related/Augmented Quality I D Non-safety-Related Open Assumptions: Yes ~ No If Yes , Enter Tracking Number Initiating Document(s): None Computer Program(s)

Program Name Version / Revision Category Status Description ETAP 20 .0.4N B Active In this calculation addendum, ETAP is used to create and analyze time-current coordination curves for overcurrent relays. The curves are from the ETAP library.

Objective or Purpose of Addendum :

Revision 1 of this calculation establishes the analytical maximum time delay for the Unit 2 degraded voltage relays (DVRs) when a safety-injection signal is present. The time delay is chosen such that the degraded voltage protection operates before the overcurrent protection during degraded voltage conditions . The calculation recommends several overcurrent relay settings changes to prevent the overcurrent protection from operating too soon . The purpose of this addendum is to document the adequacy of the recommended settings.

Scope of Addendum :

This addendum applies to overcurrent relays 51-VE214 , 51-VE216, 51-VE218, 51-VF214 , 51 -VF216, and 51-VF218.

Settings changes were recommended for these relays in Revision 1 of the calculation . This addendum confirms the recommended settings are adequate .

Describe where the Addendum will be evaluated for Regulatory Applicability.

10CFR50.59 applicability was previously evaluated in RAD and screen forms 17-03736, which are attached to Revision 1 of the calculation. The previous evaluation still applies.

Prepared By (Print, Sign , and Date):

Michael Berg ~g Berg, Michael 46983 Dec 17 2021 10:32 AM DocuS°'l"'

Reviewed/ Verified By (Print, Sign , and Date): Flaherty Jr, John 19816 John S. Flaherty, Jr.

~d~ Dec 28 2021 1:44 PM Ooc:uS'1:,,._

Approved By (Print, Sign , and Date): Lord, Christopher 48984 Christopher Lord Lord, Chrtsfopher 48984 Dec 30 2021 2:54 PM Oo<u5°'9

Page 2 of 9 energy CALCULATION ADDENDUM harbor NOP-CC-3002-02 Rev. 08 CALCULATION NO. CALCULATION REV. ADDENDUM NO.

10080-E-346 TABLE OF CONTENTS SUBJECT PAGE COVERSHEET ...... ... ....... ........ ................... ... .. .... ............... .. ....... ........... ......... .. ................ ...... ............ ...

TABLE OF CONTENTS .. ... .... ........ ..... .... ........ .... ........... .... .... .............. .... .... ... .... ........... ...... .... ..... ........ . 2 DEPARTMENT INTERFACES ............. ...... ............. ... ............... ........ ......... ... ...... .. ................................ . 2

SUMMARY

OF ADDENDUM :......................... ...................................................... .... .... .. ...................... .. 2

SUMMARY

OF RES UL TS/CONCLUSIONS OF ADDENDUM .. .......... ........ ..... .... ..... .... ....... .. .. .... ...... . 2 LIMITATIONS OR RESTRICTIONS CREATED BY ADDENDUM ... ... .... ............ .. ..... ...... ........... ..... .. . 2 IMPACT OF ADDENDUM ON OUTPUT DOCUMENTS .... .... .. ... .......... ......... ........ ... ............. ....... ... .. . 2 DOCUMENTS TO BE ADDED TO THE DOCUMENT INDEX (DIN) .................. .... .......... .. ... ..... ...... .. ... . 3 BODY OF CALCULATION: ............ .... ...... ............. ..... .... .... .... ...... ....... ................. .... ..... ............ .......... .. . 4 OBJECTIVE .. .. .... ........ ....... .. ................... ............... .. ..... ......... ... .... .... ... .. ..... .... .... ...... .......... .. ... ... ... .... . 4 METHOD OF ANALYSIS .... ........ ......................... .. ....... ..... ..... ... ........... .......... ... ... .... ....... ...... .. ... ...... .. 4 ASSUMPTIONS .. ... ... ...... .. .. ........ ...... ......... .. .... ..... ... .... ................................. .. ..... ..... ...................... ... . 5 ACCEPTANCE CRITERIA ... ...... .. .. ......... ..... .... .. ............... .. .................... ................. ... ....................... . 5 COMPUTATION .. .. .............. .. .... ....... ...... .. .. .. ..... ..... ..... .......... ....... .... ..... .. ... .. .... ................ .................. . 5 RESULTS AND CONCLUSIONS ............. ... .. ...... ........ ....................... ... .... ...... ........ ..... .. ... ..... .... ........ . 9 ATTACHMENTS :

NONE ..... .. .... ............. ... ... ....... ...... .... ..... ......... ...... .. .. .... ..... ... ..... ... .. .............. ... .. ..... ....... ... .. .... ...... ... ... . N/A TOTAL NUMBER OF PAGES IN ADDENDUM (Coversheets +Body+ Attachments) 9 Pages SUPPORTING DOCUMENTS (For Records Copy Only)

DESIGN VERIFICATION RECORD ..... ............. ..................... ........ .. ............. ....... ..... ....... ... .. ........ .... .. 1 Page CALCULATION REVIEW CHECKLIST .................... ........ ... ......... .. .. ....... ......... .. .. ..... ... .. ... .. ............... . 3 Pages DEPARTMENT INTERFACES Department Name of Person performing the Impact Review None NIA

SUMMARY

OF ADDENDUM

SUMMARY

OF RESULTS/CONCLUSIONS OF ADDENDUM :

The recommended overcurrent relay settings are adequate. The settings ensure the degraded voltage protection operates before the overcurrent protection during degraded voltage conditions. The settings adequately protect the motors.

LIMITATIONS OR RESTRICTIONS CREATED BY ADDENDUM :

The addendum does not create any limitations or restrictions .

IMPACT OF ADDENDUM ON OUTPUT DOCUMENTS :

The addendum does not affect any output documents.

Page 3 of 9 energy CALCULATION ADDENDUM harbor NOP-CC-3002-02 Rev. 08 CALCULATION NO. CALCULATION REV. ADDENDUM NO.

10080-E-346 1 DOCUMENTS TO BE ADDED TO THE DOCUMENT INDEX (DIN)

Cl) 0 ci C:

z ~

5

5 a.

z ~ a. :5 i:i Document Number/Title Revision, Edition, Date a:: E 0 BV2-VBE-011 , 4160 V Emergency Bus 2AE (Breaker 2E14) 2SWS-P21A, Rev. 3 [8:1 900 HP Service Water Pump Motor Feeder BV2-VBE-019 , 4160 V Emergency Bus 2AE (Breaker 2E16) 2SWS-P21C, Rev. 3 [8:1 900 HP Service Water Pump Motor Feeder BV2-VBE-020, 4160 V Emergency Bus 2AE (Breaker 2E18) 2FWE-P23A, Rev . 4 [8:1 400 HP Steam Generator Auxiliary Feed Pump Motor Feeder BV2-VBF-011 , 4160 V Emergency Bus 2DF (Breaker 2F14) 2SWS-P21 B, Rev. 3 [8:1 900 HP Service Water Pump Motor Feeder BV2-VBF-019 , 4160 V Emergency Bus 2DF (Breaker 2F16) 2SWS-P21C, Rev. 3 [8:1 900 HP Service Water Pump Motor Feeder BV2-VBF-020, 4160 V Emergency Bus 2DF (Breaker 2F18) 2FWE-P23B, Rev. 4

[8:1 400 HP Steam Generator Auxiliary Feed Pump Motor Feeder

Page 4 of9 energy CALCULATION ADDENDUM harbor NOP-CC-3002-02 Rev. 08 CALCULATION NO. CALCULATION REV. ADDENDUM NO.

10080-E-346 Objective Revision 1 of this calculation establishes the analytical maximum time delay for the Unit 2 degraded voltage relays {DVRs) when a safety-injection signal is present. The time delay is chosen such that the degraded voltage protection operates before the overcurrent protection during degraded voltage conditions. The calculation recommends several overcurrent relay settings changes to prevent the overcurrent protection from operating too soon. The purpose of this addendum is to document the adequacy of the recommended settings.

Method of Analysis Settings changes were recommended for the relays in the table below. In each case, the time dial setting is increased so the relay takes longer to trip. All other settings are unchanged. For relays 51-VE218 and 51-VF218, existing 51L relays (long time, extremely inverse) are replaced with 51M relays (long time, inverse) . The long-time, inverse characteristic of the 51M relays allows the time dial setting to be increased without encroaching on the motor thermal limit.

Existing Proposed Coordination Equipment Relay Checkpoint Checkpoint Setting Sheet Diagram Time {s) Time(s) 2SWS-P21A 51-VE214 2.3 2.4 BV2-VBE-011 ESK-115N 2SWS-P21C 51-VE216 2.3 2.4 BV2 -VBE-019 ESK-115P 2FWE-P23A 51-VE218 1.55 4.2 {51M) BV2-VBE-020 ESK-115R 2SWS-P21B 51-VF214 2.3 2.4 BV2-VBF-011 ESK-116N 2SWS-P21C 51-VF216 2.3 2.4 BV2-VBF-019 ESK-116P 2FWE-P23B 51-VF218 1.55 4.2 {51M) BV2-VBF-020 ESK-116R Each checkpoint time corresponds to a test current on the respective relay setting sheet. During calibration, the test current is applied to the relay, and the relay is verified to trip within +/-5% of the checkpoint time. Reference relay calibration procedure 1/2RCP-38B-PC.

The minimum operating time of each overcurrent relay is evaluated as follows:

1. The test current is obtained from the relay setting sheet .

2. The proposed checkpoint time is obtained from the preceding table.

3. The checkpoint time is adjusted to 95% of the original value. This accounts for the -5% calibration tolerance.

4. The point formed by the test current and the adjusted checkpoint time is plotted.

Page 5 of9

~ energy CALCULATION ADDENDUM

_ harbor I I NOP-CC-3002-02 Rev. 08 CALCULATION NO. ~ALCULATION REV. ~DDENDUM NO.

10080-E-346

5. The time-current characteristic curve of the overcurrent relay is plotted such that it intersects the point from the previous step.

6. The maximum motor stall current is obtained from Revision 1, Attachment 1 of the calculation .

7. Based on the maximum motor stall current, the operating time of the overcurrent relay is obtained from the time-current characteristic curve .

8. The operating time is verified to be greater than the analytical maximum time delay for the degraded voltage relays.

Steps 1 through 5 are repeated using a +5% tolerance to compare the maximum operating times of the overcurrent relays to the motor thermal limit curves.

Assumptions Motors are assumed to stall at 80% of rated voltage when starting. Maximum stall currents are estimated based on this assumption. Because the motors are specified to start successfully at 80% voltage, this assumption is conservative. If needed, margin can be recovered by demonstrating motors start successfully at lesser voltages.

Reduced voltage motor starts are analyzed in Attachment 10 to Revision 1 of the calculation .

Acceptance Criteria For a degraded voltage condition coincident with a safety-injection signal, the degraded voltage protection shall operate before the overcurrent protection . The analytical maximum time delay for the Unit 2 degraded voltage relays is 4.7 seconds when a safety-injection signal is present. Assuming motors stall when starting, the operating times of the overcurrent relays shall be greater than 4. 7 seconds.

The time-current characteristic curves of the overcurrent relays shall not intersect the motor thermal limit curves.

Computation Relays 51-VE214, 51-VE216, 51-VF214, and 51-VF216 The overcurrent relays for the service water pumps have identical test currents and settings. From the respective setting sheets, the test current is CT Ratio x Pickup Current x Checkpoint = Test Current 150 640%

5 X 5.0 A X l00% = 960 A The adjusted checkpoint time is 95%

l00% X 2.4 S = 2.28 S The motor stall current is 624 amps (from Revision 1, Attachment 1 of the calculation).

Page 6 of 9

~ energy CALCULATION ADDENDUM

_ harbor I

NOP-CC-3002-02 Rev. 08 CALCULATION NO.

10080-E-346

ALCULATION REV. I ~DDENDUM NO.

Amps X 10 (Plot Ref. kV=4.16)

.5 *t 3 5 10 30 50 100 300 1K 3K 10K 1K r-,-,c-T-r-~-~,__,-,----r,-T"TT"---.~.c-r-~--,--,c-,---,-rr,c------,--r--r--r--r,-,...,.....------.----.----.--,---,........., 1K

\

l 500 i

\

\

500

\

300 i 300

\

\*,.

\

100 100

\

\

\

50 \. *' .t--- Motor Thermal Limit 50 30 -.. 30

\

\

\

\ *,

10 10

\ ,_

\ _\*- - - Maximum Relay Trip Time 1/) 5 Minimum Relay Trip Time - - - + \

"O C: 6~4 A. 4.87 s \\

0 3 hl Cf)

\

- - Minimum Checkpoint Time 960 A. 2.28 s 1 1

.5 .5 3 .3

.'I .1

.05 .05

.03 .03

.01 L.......l-l....L'-.,___ _.____,__.__.__._..._,_.._.___ _.___,___._-'-'-'--'--'-'----'-----'---'--'--'--'-L...l...1..----'--.,__'---'--'--'--'--'--' .01

.5 1 3 5 10 30 50 100 300 *tK 3K 10K Amps X 10 (Plot Ref kV=4 .16)

CTl+P St11 20 r, *N

Page 7 of 9 energy CALCULATION ADDENDUM harbor NOP-CC-3002-02 Rev. 08 CALCULATION NO. CALCULATION REV. ADDENDUM NO.

10080-E-346 Relays 51 -VE218 and 51-VF218 The overcurrent relays for the auxiliary feedwater pumps have identical test currents and settings. From the respective setting sheets, the test current is CT Ratio x Pickup Current x Checkpoint = Test Current 100 613%

- - X 3.1 A X 100%

5

= 380 A The adjusted checkpoint time is 95%

l00o/o X 4.2 S = 3.99 S The motor stall current is 250 amps (from Revision 1, Attachment 1 of the calculation).

Page 8 of 9 energy CALCULATION ADDENDUM harbor NOP-CC-3002-02 Rev. 08 CALCULATION NO. CALCULATION REV. ADDENDUM NO.

10080-E-346 Amps X 10 (Plot Ref. kV=4 .16)

.5 1 3 5 10 30 50 100 300 1K 3K 10K 1K 1K 500 500 300 300 100 Motor Thermal Limit 100

\*,

\

50 \ 50

\ -.

\

30 \

. 30

• ~\ \._ __

Maximum Relay Trip Time 10 \\ 10

(/) 5

-g Minimum Relay Trip Time 250 A 5.13 s

~~- ---...**-.-----

, - Minimum Checkpoint Time 5 (/)

(II 8 3 380 A. 3.99 s 3 8 Q)

(/)

a.

(I) 1

.5 .5

.3 .3

.1 .1

.05 .05

.03 .03

.01 L..J...J....L...l--'----'-----'----'-...J.......J.....L.J...L.I...._--L__J'--1....J.....J....L_J...J..J.._ __J_ __.____.J.....J.-L-I....J...L.l.-..--'----'-~.J.....J....J...J....LJ

• 01

.5 1 3 5 10 30 50 100 300 1K 3K 10 K Amps X 10 (Plot Ref. kV=4 .1 6}

[T;.f' S.:n<:.>004N

Page 9 of 9

~ energy CALCULATION ADDENDUM c--.. harbor NOP-CC-3002-02 Rev . 08 CALCULATION NO.

10080-E-346 I ~ALCULATION REV. I ~DDENDUM NO.

Results and Conclusions Results are summarized in the following table.

95% of Relay Test Current Motor Stall Greater than Relay Checkpoint Operating (A) Current (A) 4.7 s?

Time(s) Time (s) 51-VE214 960 2.28 624 4.87 Yes 51-VE216 960 2.28 624 4.87 Yes 51-VE218 380 3.99 250 5.13 Yes 51-VF214 960 2.28 624 4.87 Yes 51 -VF216 960 2.28 624 4.87 Yes 51-VF218 380 3.99 250 5.13 Yes The minimum relay operating times are greater than 4.7 seconds at the maximum motor stall currents. The time-current characteristic curves of the overcurrent relays do not intersect the motor thermal limit curves. The acceptance criteria are met.

The recommended overcurrent relay settings are adequate. The settings ensure the degraded voltage protection operates before the overcurrent protection during degraded voltage conditions. The settings adequately protect the motors.

Enclosure E L-22-081 Calculation No. 8700-E-271, Revision 3, Addendum 4, "Station Service System Dynamic Stability Study" (13 pages follow)

Page 1 FustEnefJ!v CALCULATION ADDENDUM I I NOP-CC-3002-02 Rev. 07 CALCULATION NO. ~ALCULATION REV. :DDENDUM NO.

8700-E-271 181 BV1 BV2 0 BV1/2 BV3 0 BVSWT I 0 DB I 0 PY TITLE/

SUBJECT:

Station Service System Dynamic Stability Study Classification: 181 Tier 1 Calculation I 181 Safety-Related/Augmented Quality I D Non-safety-Related Open Assumptions?: D Yes 181 No If Yes, Enter Tracking Number Initiating Document(s): CR 11-95145 (PY) Referenced in USAR Validation Database D Yes D No I (PY) Referenced in Atlas? Yes D No Computer Program(s)

Program Name Version / Revision Category Status Description ETAP 11 .1.0N B Active ETAP is used to perform various types of electrical power analyses. In this calculation, transient stability studies are used to evaluate the electrical system response to transients caused by fast bus transfers and motor starting.

Excel 2016 C Active Excel is a general-purpose spreadsheet program . In this calculation, Excel is used to tabulate results and perform mathematical computations.

Originator (Print, Sign & Date) Reviewer/Design Verifier (Print, Sign & Date) Approver (Print, Sign & Date)

Michael Berg ,,,.ef/ , ~ 3/1cf/1~ Cory Murray ~}.A_,,.. 3/11.(/lt Robert Lubert /JI'~ /L 3-N,zy-OBJECTIVE OR PURPO~F ADDENDUM:

This addendum supports planned changes to the Unit 1 degraded voltage protection scheme. Presently, the degraded voltage protection scheme utilizes a 90-second time delay for both accident and non-accident conditions. The proposed scheme introduces a second, shorter time delay to be used during accident conditions. The shorter time delay ensures that safety-related equipment is transferred to the emergency diesel generators in time to support safety-injection time delay assumptions in the UFSAR accident analyses.

The system station service transformers (SSSTs) are equipped with load tap changers that regulate the voltages at the secondary sides of the transformers. Presently, the load tap changers may need to operate following fast bus transfers to allow the degraded voltage relays to reset. The SSST voltage regulation scheme is being modified such that the transformer taps are maintained in elevated positions when the transformers are unloaded. For accident conditions, this ensures the degraded voltage relays reset following fast bus transfers-without crediting the load tap changers. This permits a shorter degraded voltage time delay to be used without jeopardizing the availability of the offsite power source.

Additionally, voltage settings for the loss of voltage relays are being increased. The new voltage settings are selected so that undervoltage protection operates before overcurrent protection during degraded voltage conditions. This ensures that safety-related equipment remains available to be transferred to the emergency diesel generators.

To support the planned changes, this addendum:

1. Establishes an acceptable voltage regulation band for the SSSTs. The minimum voltage is selected such that the degraded voltage relays reset following accident-initiated fast bus transfers.

2. Determines the minimum allowable degraded voltage time delay for accident conditions. The minimum delay provides adequate time for the degraded voltage relays to reset following expected voltage transients caused by fast bus transfers or motor starts.

3. Determines the maximum allowable dropout voltage for the loss of voltage relays. The maximum dropout voltage shall be less than the minimum voltage observed at the safety-related 4160-volt buses during reactor coolant pump starts.

4. Given the limits established above, demonstrates that overcurrent and undervoltage protection does not operate during expected voltage transients caused by fast bus transfers or motor starts.

Page 2 FtrstEne.!JlV CALCULATION ADDENDUM NOP-CC-3002-02 Rev. 07 CALCULATION NO.

8700-E-271 I ~ALCULA TION REV. I ;DDENDUM NO.

SCOPE OF ADDENDUM :

After the previous addendum was completed , the scope of planned degraded voltage protection scheme changes expanded and some improvements were recommended following a third-party review. This addendum addresses the scope expansion and recommended improvements. The results of Addendum 3 are superseded by this addendum .

This addendum determines the maximum allowable dropout voltage for the loss of voltage relays. Loss of voltage relays are provided for the safety-related 4160-volt buses and the safety-related 480-volt buses. However, Table 3.3.5-1 in the Technical Specifications addresses the 4160-volt buses only. The loss of voltage relays for the 480-volt buses are not addressed in this addendum .

LIST NEW DOCUMENTS TO BE ADDED TO THE DOCUMENT INDEX (DIN).

(I)

CJ ci C:

z (I)

5 z l(I)

5 C. :5 C.

0 Document Number/Title Revision , Edition, Date a:: E 0 0321-0117-CALC-002, Beaver Valley Torque Analysis Calculation to Support Rev. A 0 Fast Bus Transfer for Unit 1 0321-0117-CALC-004, Motor Shaft Transient Torque Analysis for BVNPS U 1 Rev. 0 0 After Fast Bus Transfer 8700-DEC-0181 , Setpoint Inaccuracy Calculation for Emergency Bus Rev. 2 0

Degraded Grid Relays - ABB 27N 8700-DEC-0184, Thermal Overload Setting Review for GL 89-10 Motor Rev. 0 0 Operated Valves and Dampers 8700-DMC-2711 , Torque Calculations for MOV-1 CH-289 Rev. 7 Add . 5 0

8700-DMC-2715, Torque Calculations for MOV-1CH-310 Rev. 7 0

8700-DMC-2728 , Torque Calculations for MOV-1Sl-867C Rev. 6 Add. 2 0

8700-DMC-2730 , Torque Calculations for MOV-1 Sl-867 A and Rev. 9 0

MOV-1Sl-867B 8700-DMC-2769 , Torque Calculations for MOV-1 CH-115B and Rev. 5 0

MOV-1CH-115D 8700-DMC-2792 , Maximum Torque Outputs Accounting for Degraded Rev. 9 Add. 6 0

Voltage for Selected CH Motor Operated Valves 8700-DMC-2811 , Maximum Torque Outputs Accounting for Degraded Rev. 8 Add . 14 0

Voltage for Selected SI Motor Operated Valves 8700-DMC-2957 , MOV Weak Link Evaluation of Anchor/Darling Valves Rev. 1 0

MOV-1CH-115C, E Using ASME Allowable Stresses 8700-DMC-3035 , Torque Calculations for MOV-1 Sl-867D Rev. 4 Add. 1 0

8700-E-068, Station Service Load Flow and Voltage Profile Analysis Rev. 5 0 8700-E-221 , 4160 and 480 Volt AC Load Management and Voltage Profile Rev. 2 0 Calculations Relating to Bus 1AE 8700-E-222 , 4160 and 480 Volt AC Load Management and Voltage Profile Rev. 1 and addenda 0

Calculations Relating to Bus 1DF 8700-E-345, Voltage and Time Delay Analysis for Unit 1 Undervoltage Rev. 0 0 Protection Scheme ABB Project Number 4402581 , Positive Sequence Impedances for Rev. 1 0

FirstEnergy Beaver Valley Nuclear Power Station BV1-RBN-026, 480 V Emergency Bus 1N - Sustained Undervoltage Rev. 6 0 Protection

Page 3 FtrstEneJJrl CALCULATION ADDENDUM I

NOP-CC-3002-02 Rev. 07 CALCULATION NO. I ~ALCULATION REV. :DDENDUM NO.

8700-E-271 (I)

CJ ci s0.

C z

z ~

~

(I) s0. s i5 Document Number/Title Revision, Edition, Date 0:: E 0 BV1-RBP-026, 480 V Emergency Bus 1P - Sustained Undervoltage Rev. 6 C8J Protection BV1-VBE-029, 4160 V Emergency Bus 1AE- Sustained Undervoltage Rev. 5 C8J Protection BV1-VBF-028 , 4160 V Emergency Bus 1DF - Sustained Undervoltage Rev. 5 C8J Protection ECP 17-0336, Degraded Voltage Protection Modifications for BV1 C8J Generic Letter 89-10, Safety-Related Motor-Operated Valve Testing and June 28 , 1989 C8J Surveillance Limitorque Bulletin LM-77 , Limitorque Motors C8J Pl Database Accessed 7/13/2017 C8J

SUMMARY

OF RESULTS/CONCLUSIONS OF ADDENDUM :

When the SSSTs are unloaded , the secondary-side voltages shall be regulated to within 128.5 +/- 1.5 volts .

For accident conditions, the degraded voltage relay time delay shall be greater than 2.5 seconds. This provides adequate time for bus voltages to recover following fast bus transfers and is longer than the voltage transients associated with block starting safety-injection equipment.

The dropout voltage of the loss of voltage relays for the safety-related 4160-volt buses shall be less than 80.1 percent of the nominal bus voltage. This ensures that the relays do not drop out when starting large motors, such as the reactor coolant pump motors . To be within the bounds of this analysis, SSST taps should be raised such that secondary-side voltages are at least 127 volts before starting the 'A' reactor coolant pump. Also, the reset voltages for the loss of voltage relays shall not exceed 90 percent of the nominal bus voltage.

ANSI C50.41 volts-per-hertz limits are exceeded during fast bus transfers. Further analysis , which demonstrates the acceptability of the volts-per-hertz results , is available in MPR calculations 0321-0117-CALC-002 and 0321-0117-CALC-004 .

LIMITATIONS OR RESTRICTIONS CREATED BY ADDENDUM:

To support proposed undervoltage protection scheme modifications , this addendum establishes the minimum allowable degraded voltage time delay for accident conditions and the maximum allowable dropout voltage for the loss of voltage relays . Additionally, the addendum establishes an acceptable voltage regulation band for the SSSTs. Relays shall be set such that these limits are respected .

IMPACT OF ADDENDUM ON OUTPUT DOCUMENTS :

The results of this addendum are an input to MPR calculation 0321-0117-CALC-002, Beaver Valley Torque Analysis Calculation to Support Fast Bus Transfer for Unit 1. That calculation assesses the torques that motors are subjected to during fast bus transfers. For motors that do not satisfy the screening criteria of that calculation , more detailed analyses are documented in MPR calculation 0321-0117-CALC-004, Motor Shaft Transient Torque Analysis for BVNPS U1 After Fast Bus Transfer.

This calculation is an input to the following motor-operated valve torque calculations: 8700-DMC-2711 , 8700-DMC-2715, 8700-DMC-2728, 8700-DMC-2730, 8700-DMC-2769, 8700-DMC-2792 , 8700-DMC-2811 , 8700-DMC-2957 , and 8700-DMC-3035. Refer to Attachment 17 and DIE 21 for details.

DESCRIBE WHERE THE ADDENDUM WILL BE EVALUATED FOR 10CFR50.59 / 10CFR72.48 APPLICABILITY:

Addendum 3 to Revision 3 of the calculation was evaluated for 10CFR50.59 applicability in RAD and screen forms 15-00582. The previous evaluation still applies.

Page 4 FtrstEOE!JlV CALCULATION ADDENDUM NOP-CC-3002-02 Rev. 07 CALCULATION NO.

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LIST SUPPORTING DOCUMENTS: (Include total number of pages)

Refer to the Table of Contents.

LIST ATTACHMENTS: (Include total number of pages)

Refer to the Table of Contents .

Page 5 FtrstEoe!f!v CALCULATION ADDENDUM NOP-CC-3002-02 Rev. 07 CALCULATION NO .

8700-E-271 I ;ALCULATION REV. I :DDENDUM NO.

Table of Contents Section Title Cover 1 Table of Contents 5 Background/Objective 6 Design Inputs 6 Method of Analysis 6 Assumptions 10 Acceptance Criteria 10 Computation 11 Results 12 Conclusions 13 Subtotal 13 Pages Attachment 1 Transient Stability Analysis Report - Study Case FBT-US-NH 352 Pages Attachment 2 Transient Stability Analysis Report - Study Case FBT-US-NL 352 Pages Attachment 3 Transient Stability Analysis Report- Study Case FBT-US-SH 705 Pages Attachment 4 Transient Stability Analysis Report- Study Case FBT-US-SL 705 Pages Attachment 5 Transient Stability Analysis Report - Study Case FBT-US-FH 383 Pages Attachment 6 Transient Stability Analysis Report - Study Case FBT-US-FL 383 Pages Attachment 7 Transient Stability Analysis Report - Study Case FBT-SU-NH 352 Pages Attachment 8 Transient Stability Analysis Report - Study Case FBT-SU-NL 352 Pages Attachment 9 Transient Stability Analysis Report - Study Case MS-RCP 441 Pages Attachment 1O Transient Stability Analysis Report - Study Case MS-SI 360 Pages Attachment 11 Voltage Plots from Transient Stability Study Cases 20 Pages Attachment 12 Maximum Motor Currents During Fast Bus Transfer 2 Pages Attachment 13 Fast Bus Transfer Volts-per-Hertz Summary 9 Pages Attachment 14 Information to Support Torque Analysis for Safety-Related Fans 83 Pages Attachment 15 SSST Impedance Analysis 7 Pages Attachment 16 Bus Diversity Factors 77 Pages Attachment 17 Motor-Operated Valve Minimum Voltage Evaluation 3 Pages Design Verification Record 1 Page Calculation Review Checklist 3 Pages Design Interface Summary 8 Pages Design Interface Evaluations 32 Pages Subtotal 4630 Pages Total 4643 Pages

Page 6 FtrstEnefJlY CALCULATION ADDENDUM I I NOP-CC-3002-02 Rev. 07 CALCULATION NO. ~ALCULATION REV. :DDENDUM NO.

8700-E-271 Bae kg round/Objective This addendum supports planned changes to the Unit 1 degraded voltage protection scheme. Presently, the degraded voltage protection scheme utilizes a 90-second time delay for both accident and non-accident conditions . The proposed scheme introduces a second , shorter time delay to be used during accident conditions. The shorter time delay ensures that safety-related equipment is transferred to the emergency diesel generators in time to support safety-injection time delay assumptions in the UFSAR accident analyses.

The system station service transformers (SSSTs) are equipped with load tap changers that regulate the voltages at the secondary sides of the transformers. Presently, the load tap changers may need to operate following fast bus transfers to allow the degraded voltage relays to reset. The SSST voltage regulation scheme is being modified such that the transformer taps are maintained in elevated positions when the transformers are unloaded. For accident conditions , this ensures the degraded voltage relays reset following fast bus transfers-without crediting the load tap changers. This permits a shorter degraded voltage time delay to be used without jeopardizing the availability of the offsite power source.

Additionally, voltage settings for the loss of voltage relays are being increased. The new voltage settings are selected so that undervoltage protection operates before overcurrent protection during degraded voltage conditions. This ensures that safety-related equipment remains available to be transferred to the emergency diesel generators.

To support the planned changes , this addendum:

1. Establ ishes an acceptable voltage regulation band for the SSSTs. The minimum voltage is selected such that the degraded voltage relays reset following accident-initiated fast bus transfers.

2. Determines the minimum allowable degraded voltage time delay for accident conditions. The minimum delay provides adequate time for the degraded voltage relays to reset following expected voltage transients caused by fast bus transfers or motor starts .

3. Determines the maximum allowable dropout voltage for the loss of voltage relays. The maximum dropout voltage shall be less than the minimum voltage observed at the safety-related 4160-volt buses during reactor coolant pump starts .

4. Given the limits established above, demonstrates that overcurrent and undervoltage protection does not operate during expected voltage transients caused by fast bus transfers or motor starts .

Design Inputs Degraded voltage relay reset values, including uncertainties, are obtained from calculation 8700-DEC-0181 Rev. 2, page 16.

SSST impedance variations with respect to tap are based on a calculation by ABB . The associated report is included in 5.

Bus diversity factors are based on historical load data from the Pl database. Load data were obtained at 6-hour intervals from 7/12/2008 to 7/12/2017 . Refer to Attachment 16 for additional information.

Minimum bus voltage limits following a safety injection are based on the voltages analyzed in calculations 8700-E-221 and 8700-E-222 . Refer to the Acceptance Criteria section for additional details.

This addendum utilizes a modified version of the ETAP model from the previous addendum . Except as noted, design inputs are unchanged from the previous addendum .

Method of Analysis General Method This addendum uses the same general analysis approach as the previous addendum . A model of the Beaver Valley Unit 1 electrical distribution system is created using ETAP. The ETAP transient stability module is used to simulate electrical transients caused by fast bus transfers , motor starts, etc. The results of these simulations are reviewed to establish equipment operating limits and confirm that calculation acceptance criteria are met.

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8700-E-271 Calculation Changes After the previous addendum was completed , the scope of planned undervoltage protection scheme changes expanded and some improvements were recommended following a third-party review. This addendum addresses the scope expansion and recommended improvements. This addendum differs from the previous addendum in that

1. The voltages at the secondary sides of the SSSTs are regulated . The previous addendum evaluated voltages based on fixed SSST tap positions .

2. Voltage decreases in the offsite power source caused by tripping the main unit generator are considered. The decreases are based on post-contingency voltage drop warning limits maintained by PJM.

3. The minimum allowable degraded voltage time delay is determined based on the times it takes the degraded voltage relays to reset following expected voltage transients . In contrast, the previous addendum verified that the degraded voltage relays reset within a predetermined time delay of six seconds.

4. This addendum accounts for SSST impedance variations with respect to tap position. The previous addendum utilized fixed impedance values regardless of tap position.

5. A study case that addresses block starting safety-injection equipment from the SSSTs during steady-state conditions (i .e. without fast bus transfers) is included .

6. Beyond-design-basis study cases from the previous addendum are omitted. These study cases involved block starting safety-injection equipment coincident with or shortly after fast bus transfers. Each case postulated an independent fast bus transfer and safety injection as opposed to a safety injection and consequential fast bus transfer. For the most credible safety-injection scenarios, safety-injection equipment starts from the unit station service transformers (USSTs) and is transferred to the SSSTs after a 30 second time delay.

7. A study case that addresses reactor coolant pump motor starting is included. This is necessary, because voltage settings for the loss of voltage relays are being increased. The reactor coolant pump motors yield the most severe motor starting transients.

8. A study case that addresses fast bus transfer from the SSSTs to the USSTs is included. This is necessary, because voltage settings for the loss of voltage relays are being increased .

9. The negative lumped loads used to model load diversity are revised . A review of historical load data from the Pl database showed that the bus loads in the previous addendum are too low. This addendum updates the diversity factors to better match the Pl data. Refer to Attachment 16 for more details. Section 7.16 of calculation 8700-E-068 Rev. 5 describes the general method for determining the negative lumped loads.

10. The acceptance criterion for degraded voltage relay reset is changed . The previous acceptance criterion was based on the maximum values dictated on the relay setting sheets, which do not include calibration inaccuracies. The new acceptance criterion takes these inaccuracies into account.

11 . For some Square D Masterpact breakers, the minimum instantaneous trip currents used to determine whether the breakers operate during fast bus transfers are updated. The previous addendum did not account for the breaker short-time units, which are set with zero time delay and may trip at lower currents than the instantaneous units.

Study Case Descriptions The SSST voltage regulation scheme is being modified such that the transformer taps are maintained in elevated positions when the transformers are unloaded. In the ETAP model, voltage regulation settings and tap positions are controlled using revisions. Each revision is described in the following table . Voltages are specified in terms of potential-transformer secondary voltages, which differ from the primary voltages by a factor of 35 . (The potential-transformer ratio is 4200/120).

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8700-E-271 Revision Description LTC-MAX-S This revision is based on existing voltage regulating relay (VRR) settings. The existing setting is 123.5 +/- 1.5 volts accounting for bandwidth and setting tolerances. The maximum voltage is therefore 125.0 volts. SSST taps are regulated such that the secondary-side voltages are at least 125.0 volts . This revision is used for maximum voltage conditions when buses are aligned to the SSSTs.

LTC-MIN-S This revision is based on existing VRR settings. The existing setting is 123.5 +/- 1.5 volts accounting for bandwidth and setting tolerances. The minimum voltage is therefore 122.0 volts. SSST taps are regulated such that the secondary-side voltages are at most 122.0 volts. This revision is used for minimum voltage conditions when buses are aligned to the SSSTs.

LTC-MAX-U This revision is based on proposed VRR settings. The proposed setting is 128.5 +/- 1.5 volts accounting for bandwidth and setting tolerances. The maximum voltage is therefore 130.0 volts . SSST taps are regulated such that the secondary-side voltages are at least 130.0 volts. This revision is used for maximum voltage conditions when buses are aligned to the USSTs.

LTC-MIN-U This revision is based on proposed VRR settings . The proposed setting is 128.5 +/- 1.5 volts accounting for bandwidth and setting tolerances. The minimum voltage is therefore 127.0 volts. SSST taps are regulated such that the secondary-side voltages are at most 127. 0 volts when the voltages at the 138-kV buses are 100 percent of the nominal voltage. The corresponding taps are then fixed , and the 138-kV bus voltage is reduced to 98.5 percent. This accounts for a 1.5 percent voltage drop caused by a unit trip . This revision is used for minimum voltage conditions when buses are aligned to the USSTs.

LTC-RCP-S This revision addresses manual SSST tap changes before starting the 'A' reactor coolant pump. SSST taps are regulated such that the secondary-side voltages are at most 127.0 volts .

LTC-S1-S This revision is based on existing VRR settings. The existing setting is 123.5 +/- 1.5 volts accounting for bandwidth and setting tolerances. The minimum voltage is therefore 122.0 volts . SSST taps are regulated such that the secondary-side voltages are at most 122.0 volts when the voltages at the 138-kV buses are 100 percent of the nominal voltage. The corresponding taps are then fixed , and the 138-kV bus voltage is reduced to 98.5 percent. This accounts for a 1.5 percent voltage drop caused by a unit trip. This revision is used for minimum-voltage, safety-injection conditions when buses are aligned to the SSSTs.

ETAP configurations are used to control breaker positions , which determine whether buses are aligned to offsite or onsite power and determine what motors are running for given scenario (e.g. normal operation , safety injection). Each configuration is described in the following table .

Configuration Description S-N-NX This configuration is used for normal operation with buses aligned to the SSSTs. Non-safety-related 480-volt buses are not cross-tied .

S-S-NX This configuration is used for study cases that address safety-injection conditions. In contrast to the normal configuration, breakers associated with the low-head safety-injection pumps and auxiliary feedwater pumps are closed. Buses are aligned to the SSSTs.

U-N-NX This configuration is identical to S-N-NX except that buses are aligned to the USSTs.

U-S-NX This configuration is identical to S-S-NX except that buses are aligned to the USSTs.

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8700-E-271 ETAP study cases are summarized in the following table . Unit trip/safety injection/fast bus transfer scenarios that were previously split across two study cases have each been consolidated into one study case. Study cases have also been renamed to be more descriptive. For example , study case FBT-US-SL involves a fast bus transfer (FBT) from the unit station service transformers to the system station service transformers (US) for safety injection conditions with low voltages (SL) .

Study case FBT-SU-NH involves a fast bus transfer (FBT) from the system station service transformers to the unit station service transformers (SU) for normal operating conditions with high voltages (NH). Cross-references to the former study case names are included in parenthesis.

Study Case Revision Configuration Description FBT-US-NH LTC-MAX-U U-N-NX This study case evaluates a fast bus transfer from the USSTs to the (12A2X) SSSTs for maximum-voltage, non-accident conditions.

FBT-US-NL LTC-MIN-U U-N-NX This study case evaluates a fast bus transfer from the USSTs to the (12A1X) SSSTs for minimum-voltage, non-accident conditions . A 1.5 percent decrease in the 138-kV bus voltage due to a unit trip is considered.

FBT-US-SH LTC-MAX-U U-S-NX This study case evaluates a fast bus transfer from the USSTs to the (15-1B , 16BX) SSSTs for maximum-voltage, safety-injection conditions. This case involves a turbine trip at t =Os, a safety injection at t = 10 s, and a fast bus transfer at t = 30 s.

The safety injection causes the river water pumps, high-head safety-injection pumps , low-head safety-injection pumps, auxiliary feedwater pumps , and various MOVs to start. The MOV starting current is reduced to running current after 2 seconds . To yield worst-case motor starting transients, the river water pumps and high-head safety-injection pumps (which run during normal operation) are considered to start.

The safety injection causes the main feedwater pumps to trip.

FBT-US-SL LTC-MIN-U U-S-NX This study case is similar to FBT-US-SH but addresses minimum-(15-1A, 16AX) voltage conditions. A 1.5 percent decrease in the 138-kV bus voltage due to a unit trip is considered.

FBT-US-FH LTC-MAX-U U-N-NX This study case evaluates a fast bus transfer from the USSTs to the (5B1X) SSSTs following a fault on the high side of the main transformer. The fault is applied at t = 0 s; a fast bus transfer occurs at t = 0.067 s. This study case is performed for maximum-voltage conditions.

FBT-US-FL LTC-MIN-U U-N-NX This study case evaluates a fast bus transfer from the USSTs to the (5A1X) SSSTs following a fault on the high side of the main transformer. The fault is applied at t =Os; a fast bus transfer occurs at t = 0.067 s. This study case is performed for minimum-voltage conditions. A 1.5 percent decrease in the 138-kV bus voltage due to a unit trip is considered .

FBT-SU-NH LTC-MAX-S S-N-NX This study case evaluates a fast bus transfer from the SSSTs to the (4B , 12B) USSTs for maximum-voltage, non-accident conditions.

FBT-SU-NL LTC-MIN-S S-N-NX This study case evaluates a fast bus transfer from the SSSTs to the USSTs for minimum-voltage, non-accident conditions.

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Study Case Revision Configuration Description MS-RCP LTC-RCP-S S-N-NX This study case evaluates starting the 'A' reactor coolant pump under (1) minimum-voltage conditions. The A pump is selected , because it is upstream of safety-related bus 1AE. The other reactor coolant pumps are upstream of non-safety-related buses.

MS-SI LTC-SI-S S-S-NX This study case evaluates starting safety-injection equipment from the SSSTs under minimum-voltage conditions. After starting , motor-operated valves are considered to draw locked-rotor current through the end of the simulation . A 1.5 percent decrease in the 138-kV bus voltage due to a unit trip is considered .

The previous addendum included a load flow study case (LF1-Minld-SX) that addressed maximum voltage, minimum load conditions . The changes incorporated into this addendum do not necessitate revisiting that study case.

Assumptions The minimum allowable degraded voltage time delay for accident conditions is based on the lengths of the voltage transients caused by block starting safety-injection equipment or by fast bus transfers . These transients are an expected consequence of a safety-injection signal. Some actions-such as manually starting a large 480-volt fan-can yield longer voltage transients.

For those transients not caused by automatic response to a safety-injection signal, it is assumed that procedural controls are sufficient to avoid unnecessary operation of the degraded voltage protection .

Acceptance Criteria Voltage Regulation Band for the SSSTs The SSST voltage regulation scheme is being modified such that the transformer taps are maintained in elevated positions when the transformers are unloaded. For accident conditions , this ensures the degraded voltage relays reset following fast bus transfers-without crediting the load tap changers. This addendum establishes an acceptable voltage regulation band for the SSSTs. The minimum voltage is selected such that the degraded voltage relays reset following accident-initiated fast bus transfers. For the degraded voltage relays at the safety-related 4160-volt buses to reset, voltages shall recover above 95.313 percent of the nominal bus voltage . For the 480-volt buses, voltages shall recover above 95.243 percent. (Refer to calculation 8700-DEC-0181 Rev. 2, page 16.) For conservatism , the higher acceptance criterion is used for both sets of buses.

For the non-accident cases , it is less critical that the degraded voltage relays reset immediately following fast bus transfer. In those cases , credit may be taken for the 90-second degraded voltage relay time delay and the load tap changers. The load tap changers operate after an initial 30-second time delay, and each tap change takes approximately 5 seconds.

From IEEE C57.12.00, the maximum voltage on the secondary side of an unloaded transformer shall not exceed 110 percent of the voltage rating. Accordingly, the maximum voltage shall be less than 110 percent of 4360 volts (i.e. 4796 volts).

Minimum Allowable Degraded Voltage Time Delay This addendum determines the minimum allowable degraded voltage time delay for accident conditions. The minimum delay provides adequate time for the degraded voltage relays to reset following expected voltage transients caused by fast bus transfers or motor starts. The minimum time delay shall exceed the lengths of the voltage transients caused by block starting safety-injection equipment or by fast bus transfers-whichever is more limiting.

Maximum Allowable Dropout Voltage for the Loss of Voltage Relays This addendum determines maximum allowable dropout voltage for the loss of voltage relays . The maximum dropout voltage shall be less than the minimum voltage observed at the safety-related 4160-volt buses during reactor coolant pump starts.

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Other Considerations Given the limits established above, the addendum demonstrates that overcurrent and undervoltage protection does not operate during expected voltage transients caused by fast bus transfers or motor starts . For the fast bus transfer study cases, the following criteria shall be met

1. Upon breaker closure , motor currents shall not exceed the minimum instantaneous trip settings of the associated overcurrent relays.

2. In accordance with ANSI C50.41 , the resultant volts-per-hertz (V/Hz) vector between the incoming source and the motor at the instant of transfer should not exceed 1.33 per unit volts per hertz on the motor rated voltage and frequency basis . In cases where this acceptance criterion is not met, additional analyses are documented in MPR calculations 0321-0117-CALC-002 and 0321-0117-CALC-004.

3. For accident conditions , voltages at the safety-related 4160-volt and 480-volt buses shall recover above 95 .313 percent of the nominal bus voltages within the minimum allowable degraded voltage time delay established in this addendum.

4. Voltages at the safety-related 4160-volt buses should recover above 90 percent of the nominal bus voltage within 0.9 seconds. 0.9 seconds is the minimum time delay for the loss of voltage relays. The present reset setting for the loss of voltage relays is 84. 13 percent. A higher voltage is used in this calculation to provide marg in to increase the setting .

For the motor starting study cases involving a safety-injection, voltages should not drop below 92.4 percent at the safety-related 4160-volt and 92 .5 percent at the safety-related 480-volt buses. This ensures that the bus voltages remain within the bounds of the analyses in calculations 8700-E-221 and 8700-E-222. These calculations demonstrate that motors have adequate voltage to start and run when bus voltages are near the degraded voltage relay dropout settings. For conservatism ,

the higher acceptance criterion is used for both sets of buses.

Computation ETAP output reports for each study case are included in attachments 1 through 10. Relevant voltage plots for all study cases are consolidated in Attachment 11 . Motor currents during fast bus transfers are compared to overcurrent trip settings in 2. Volts-per-hertz values during fast bus transfers are shown in Attachment 13.

Terminal voltage, acceleration power, electrical power, mechanical power, and slip information for select safety-related fans is tabulated in Attachment 14; this information is used as an input to MPR calculation 0321-0117-CALC-004.

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8700-E-271 Results The proposed voltage regulation band for the SSSTs is 128.5 +/- 1.5 volts . The maximum voltage of 130.0 volts (4550 volts) does not exceed 110 percent of the transformer voltage rating (4796 volts).

For the fast bus transfer study cases, recovery voltages following fast bus transfers are summarized in the table below. Only the minimum-voltage cases are included, because they are more limiting than the maximum-voltage cases . The voltage acceptance criterion is met in the safety-injection case , which confirms the adequacy of the proposed voltage regulation settings for the SSSTs; the degraded voltage relays reset in less than 1.3 seconds.

Bus Voltage(%) Following Fast Bus Transfer (Acceptance Criterion> 95.313%, FBT-US-SL only)

Bus FBT-US-NL FBT-US-SL FBT-US-FL FBT-SU-NL 1AE 97 .62% 98 .33% 97 .37% 100.73%

1DF 97 .51 % 98.29% 97 .26% 100.66%

1N 95.03% 95.44% 94 .78% 98 .19%

1P 94.81 % 95.45% 94.55% 98 .02%

Relevant voltage plots for each study case are included in Attachment 11 . Based on a review of the plots, voltage transients associated with block starting safety-injection equipment subside within 2.5 seconds. 2.5 seconds is an acceptable minimum bound for the degraded voltage relay time delay during accident conditions .

The voltage at bus 1AE drops to 80.19 percent when starting the 'A' reactor coolant pump under minimum voltage conditions .

80.1 percent is an acceptable maximum bound for the dropout voltage of the loss of voltage relays.

Motor currents during fast bus transfers are compared to overcurrent trip settings in Attachment 12. The results show that overcurrent protective devices do not operate during fast bus transfers .

Volts-per-hertz values during fast bus transfers are tabulated in Attachment 13. The results show that the volts-per-hertz acceptance criterion is exceeded in many cases. Further analysis, which demonstrates the acceptability of the results, is available in MPR calculations 0321-0117-CALC-002 and 0321-0117-CALC-004.

Reset times for the loss of voltage relays during fast bus transfer are summarized in the following table . For conservatism , the relays are considered to drop out when the bus supply breakers open (or-for study case FBT-US-FL-when the fault occurs).

Only the minimum voltage cases are included, because recovery times in the maximum voltage cases are shorter. The acceptance criterion is met in all cases , which confirms that the loss of voltage relays do not operate during fast bus transfers.

Loss of Voltage Relay Reset Times (s) (Acceptance Criterion< 0.9 s)

Bus FBT-US-NL FBT-US-SL FBT-US-FL FBT-SU-NL 1AE 0.404 0.384 0.841 0.414 1DF 0.664 0.734 0.811 0.574

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The minimum bus voltages when starting safety-injection equipment are compared to the minimum voltages analyzed in calculations 8700-E-221 and 8700-E-222 . The results are summarized in the following table. Only the minimum-voltage cases are included , because they are more limiting than the maximum-voltage cases.

Minimum Bus Voltage (%) when Starting Safety-Injection Equipment (Acceptance Criterion> 92.5%)

Bus FBT-US-SL MS-SI 1AE 95.36 (at 10.201 s) 93.47 (at 1.231 s) 1DF 95.46 (at 10.201 s) 93.56 (at 1.231 s) 1N 90.87 (at 10.251 s) 88.98 (at 1.251 s) 1P 91 .92 (at 10.251 s) 89.98 (at 1.251 s)

At the 480-volt buses, the transient voltages are less than the minimum voltages analyzed in calculations 8700-E-221 and 8700-E-222 . This primarily affects motor-operated valves that start in response to a safety-injection signal. Each affected valve was analyzed to confirm that it has adequate torque to perform its function at reduced voltage . Details are available in 7. Bus voltages recover to the degraded voltage relay reset value while the motor-operated valves are drawing locked rotor currents. This demonstrates that the start times of the motor-operated valves do not prevent the degraded voltage relays from resetting within the allotted time delay.

Conclusions When the SSSTs are unloaded , the secondary-side voltages shall be regulated to within 128.5 +/- 1.5 volts.

For accident conditions, the degraded voltage relay time delay shall be greater than 2.5 seconds. This provides adequate time for bus voltages to recover following fast bus transfers and is longer than the voltage transients associated with block starting safety-injection equipment. To minimize the potential for inadvertent relay actuation and to preserve operating margin , the time delay should be as long as permissible. (Refer to calculation 8700-E-345 .)

The dropout voltage of the loss of voltage relays for the safety-related 4160-volt buses shall be less than 80.1 percent of the nominal bus voltage . This ensures that the relays do not drop out when starting large motors, such as the reactor coolant pump motors . To minimize the potential for inadvertent relay actuation and to preserve operating margin , the dropout setting should be as low as permissible. (Refer to calculation 8700-E-345.) To be within the bounds of this analysis , SSST taps should be raised such that secondary-side voltages are at least 127 volts before starting the 'A' reactor coolant pump. Also, the reset voltages for the loss of voltage relays shall not exceed 90 percent of the nominal bus voltage.

ANSI C50.41 volts-per-hertz limits are exceeded during fast bus transfers. Further analysis , which demonstrates the acceptability of the volts-per-hertz results, is available in MPR calculations 0321-0117-CALC-002 and 0321-0117-CALC-004.

Enclosure F L-22-081 Calculation No. 10080-E-271 , Revision 1, Addendum 6, "BVPS Unit-2 Transient Stability Analysis" (12 pages follow)

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10080-E-271 0 BV1 ~ BV2 0 BV1/2 0 BV3 0 BVSWT I 0 DB I 0 PY TITLE/

SUBJECT:

BVPS Unit-2 Transient Stability Analysis Classification: ~ Tier 1 Calculation I ~ Safety-Related/Augmented Quality I D Non-safety-Related Open Assumptions?: D Yes ~ No If Yes, Enter Tracking Number Initiating Document(s): CR 11-95145 (PY) Referenced in USAR Validation Database D Yes D No I (PY) Referenced in Atlas? D Yes D No Computer Program(s)

Program Name Version I Revision Category Status Description ETAP 11 .1 ON B Active ETAP is used to perform various types of electrical power analyses . In this calculation, transient stability studies are used to evaluate the electrical system response to transients caused by fast bus transfers and motor starting.

Excel 2016 C Active Excel is a general-purpose spreadsheet program . In this calculation , Excel is used to tabulate results and perform mathematical computations.

Originator (Print, Sign & O a t ~ Reviewer/Design Verifier (Print, Sign &/ate) Approver (Print, Sign & Date)

Michael Berg ~ IZ(f:1/1? Cory Murray b f;.,r * ""'-,.,-- l'J./ 17 Robert Lubert /?EH!'/, /ijy17 OBJECTIVE OR PURPOSE 'Q.vADDENDUM:

This addendum supports planned changes to the Unit 2 degraded voltage protection scheme. Presently, the degraded voltage protection scheme utilizes a 90-second time delay for both accident and non-accident conditions . The proposed scheme introduces a second, shorter time delay to be used during accident conditions. The shorter time delay ensures that safety-related equipment is transferred to the emergency diesel generators in time to support safety-injection time delay assumptions in the UFSAR accident analyses.

The system station service transformers (SSSTs) are equipped with load tap changers that regulate the voltages at the secondary sides of the transformers. Presently, the load tap changers may need to operate following fast bus transfers to allow the degraded voltage relays to reset. The SSST voltage regulation scheme is being modified such that the transformer taps are maintained in elevated positions when the transformers are unloaded . This ensures the degraded voltage relays reset following fast bus transfers-without crediting the load tap changers . This permits a shorter degraded voltage time delay to be used without jeopardizing the availability of the offsite power source .

Additionally, voltage settings for the loss of voltage relays are being increased. The new voltage settings are selected so that undervoltage protection operates before overcurrent protection during degraded voltage conditions. This ensures that safety-related equipment remains available to be transferred to the emergency diesel generators.

To support the planned changes , this addendum :

1. Establishes an acceptable voltage regulation band for the SSSTs . The minimum voltage is selected such that the degraded voltage relays reset following fast bus transfers.

2. Determines the minimum allowable degraded voltage time delay for accident conditions. The minimum delay provides adequate time for the degraded voltage relays to reset following expected voltage transients caused by fast bus transfers or motor starts.

3. Determines the maximum allowable dropout voltage for the loss of voltage relays. The maximum dropout voltage shall be less than the minimum voltage observed at the safety-related 4160-volt buses during reactor coolant pump starts.

4. Given the limits established above, demonstrates that overcurrent and undervoltage protection does not operate during expected voltage transients caused by fast bus transfers or motor starts.

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SCOPE OF ADDENDUM :

After the previous addendum was completed , the scope of planned degraded voltage protection scheme changes expanded and some improvements were recommended following a third-party review. This addendum addresses the scope expansion and recommended improvements. The results of Addendum 5 are superseded by this addendum.

This addendum determines the maximum allowable dropout voltage for the loss of voltage relays. Loss of voltage relays are provided for the safety-related 4160-volt buses and the safety-related 480-volt buses. However, Table 3.3.5-1 in the Technical Specifications addresses the 4160-volt buses only. The loss of voltage relays for the 480-volt buses are not addressed in this addendum .

LIST NEW DOCUMENTS TO BE ADDED TO THE DOCUMENT INDEX (DIN).

Ql u

0 C z ~

5

5 z -s C.

-2!

Ql C.

0 Document Number/Title Revision , Edition, Date 0::: .E: 0 0321-0117-CALC-001 , Beaver Valley Torque Analysis Calculation to Support Rev. A Fast Bus Transfer for Unit 2

~

0321-0117-CALC-003, Motor Shaft Transient Torque Analysis for BVNPS U2 Rev. 0 ~

After Fast Bus Transfer 10080-E-068, Station Service Voltage and Load Analysis Rev. 5 [8J 10080-E-221 , 4160 and 480 Volt Load Management and Voltage Profile Rev. 0 and addenda [8J Calculations Relating to Emergency Bus 2AE 10080-E-222, 4160 and 480 Volt Load Management and Voltage Profile Rev. 0 and addenda [8J Calculations Relating to Emergency Bus 2DF 10080-E-346, Voltage and Time Delay Analysis for Unit 2 Undervoltage Rev. 0 (draft) [8J Protection Scheme BV2-RBN-003, 480 V Emergency Bus 2N - Sustained Undervoltage Rev. 6 [8J Protection BV2-RBP-003 , 480 V Emergency Bus 2P - Sustained Undervoltage Rev. 6 [8J Protection BV2-VBE-015, 4160 V Emergency Bus 2AE- Sustained Undervoltage Rev. 6

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Protection BV2-VBF-015, 4160 V Emergency Bus 2DF - Sustained Undervoltage Rev. 6 Protection

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ECP 17-0257, Degraded Voltage Protection Modifications for BV2 [8J

SUMMARY

OF RESULTS/CONCLUSIONS OF ADDENDUM :

When the SSSTs are unloaded , the secondary-side voltages shall be regulated to within 128 +/- 1.5 volts .

For accident conditions , the degraded voltage relay time delay shall be greater than 2.2 seconds. This provides adequate time for bus voltages to recover following fast bus transfers and is longer than the voltage transients associated with block starting safety-injection equipment.

The dropout voltage of the loss of voltage relays for the safety-related 4160-volt buses shall be less than 84 percent of the nominal bus voltage. This ensures that the relays do not drop out when starting large motors, such as the reactor coolant pump motors. To be within the bounds of this analysis , the relay reset voltages shall not exceed 90 percent of the nominal bus voltage.

Except for the ANSI C50.41 volts-per-hertz limits, calculation acceptance criteria are met. Further analysis , which demonstrates the acceptability of the volts-per-hertz results , is available in MPR calculations 0321-0117-CALC-001 and 0321-0117-CALC-003.

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10080-E-271 LIMITATIONS OR RESTRICTIONS CREATED BY ADDENDUM:

To support proposed undervoltage protection scheme modifications, this addendum establishes the minimum allowable degraded voltage time delay for accident conditions and the maximum allowable dropout voltage for the loss of voltage relays. Additionally, the addendum establishes an acceptable voltage regulation band for the SSSTs. Relays shall be set such that these limits are respected .

IMPACT OF ADDENDUM ON OUTPUT DOCUMENTS:

The results of this addendum are an input to MPR calculation 0321-0117-CALC-001 , Beaver Valley Torque Analysis Calculation to Support Fast Bus Transfer for Unit 2. That calculation assesses the torques that motors are subjected to during fast bus transfers. For motors that do not satisfy the screening criteria of that calculation, more detailed analyses are documented in MPR calculation 0321-0117-CALC-003, Motor Shaft Transient Torque Analysis for BVNPS U2 After Fast Bus Transfer.

DESCRIBE WHERE THE ADDENDUM WILL BE EVALUATED FOR 10CFR50.59 / 10CFR72.48 APPLICABILITY:

Addendum 4 to Revision 1 of the calculation was evaluated for 10CFR50.59 applicability in RAD and screen forms 15-01516. The previous evaluation still applies.

LIST SUPPORTING DOCUMENTS: (Include total number of pages)

Refer to the Table of Contents.

LIST ATTACHMENTS: (Include total number of pages)

Refer to the Table of Contents.

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10080-E-271 Table of Contents Section Title Cover 1 Table of Contents 4 Background/Objective 5 Design Inputs 5 Method of Analysis 5 Assumptions 9 Acceptance Criteria 9 Computation 10 Results 10 Conclusions 11 Subtotal 12 Pages Attachment 1 Transient Stability Analysis Report - Study Case FBT- US-NH 367 Pages Attachment 2 Transient Stability Analysis Report - Study Case FBT-US-NL 367 Pages Attachment 3 Transient Stability Analysis Report - Study Case FBT-US-SH 490 Pages Attachment 4 Transient Stability Analysis Report - Study Case FBT-US-SL 490 Pages Attachment 5 Transient Stability Analysis Report - Study Case FBT-US-FH 396 Pages Attachment 6 Transient Stability Analysis Report - Study Case FBT-US-FL 396 Pages Attachment 7 Transient Stability Analysis Report - Study Case FBT-SU-NH 370 Pages Attachment 8 Transient Stability Analysis Report- Study Case FBT-SU-NL 370 Pages Attachment 9 Transient Stability Analysis Report - Study Case MS-RCP 273 Pages Attachment 10 Transient Stability Analysis Report - Study Case MS-SI 544 Pages Attachment 11 Voltage Plots from Transient Stability Study Cases 20 Pages Attachment 12 Maximum Motor Currents During Fast Bus Transfer 2 Pages Attachment 13 Fast Bus Transfer Volts-per-Hertz Summary 9 Pages Attachment 14 Information to Support Torque Analysis for Safety-Related Fans 329 Pages Attachment 15 SSST Impedance Test Results 6 Pages Design Verification Record 1 Page Calculation Review Checklist 3 Pages Design Interface Summary 9 Pages Subtotal 4442 Pages Total 4454 Pages

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Background/Objective This addendum supports planned changes to the Unit 2 degraded voltage protection scheme. Presently, the degraded voltage protection scheme utilizes a 90-second time delay for both accident and non-accident conditions . The proposed scheme introduces a second , shorter time delay to be used during accident conditions. The shorter time delay ensures that safety-related equipment is transferred to the emergency diesel generators in time to support safety-injection time delay assumptions in the UFSAR accident analyses.

The system station service transformers (SSSTs) are equipped with load tap changers that regulate the voltages at the secondary sides of the transformers. Presently, the load tap changers may need to operate following fast bus transfers to allow the degraded voltage relays to reset. The SSST voltage regulation scheme is being modified such that the transformer taps are maintained in elevated positions when the transformers are unloaded. This ensures the degraded voltage relays reset following fast bus transfers-without crediting the load tap changers . This permits a shorter degraded voltage time delay to be used without jeopardizing the availability of the offsite power source.

Additionally, voltage settings for the loss of voltage relays are being increased . The new voltage settings are selected so that undervoltage protection operates before overcurrent protection during degraded voltage conditions. This ensures that safety-related equipment remains available to be transferred to the emergency diesel generators.

To support the planned changes, this addendum :

1. Establishes an acceptable voltage regulation band for the SSSTs . The minimum voltage is selected such that the degraded voltage relays reset following fast bus transfers.

2. Determines the minimum allowable degraded voltage time delay for accident conditions. The minimum delay provides adequate time for the degraded voltage relays to reset following expected voltage transients caused by fast bus transfers or motor starts.

3. Determines the maximum allowable dropout voltage for the loss of voltage relays . The maximum dropout voltage shall be less than the min imum voltage observed at the safety-related 4160-volt buses during reactor coolant pump starts .

4. Given the limits established above , demonstrates that overcurrent and undervoltage protection does not operate during expected voltage transients caused by fast bus transfers or motor starts.

Design Inputs SSST impedance variations with respect to tap are based on original test data for the transformers. The test results are included in Attachment 15.

Minimum bus voltage limits following a safety injection are based on the voltages analyzed in calculations 10080-E-22 1 and 10080-E-222. Refer to the Acceptance Criteria section for additional details.

This addendum utilizes a modified version of the ETAP model from the previous addendum . Except as noted , design inputs are unchanged from the previous addendum.

Method of Analysis General Method This addendum uses the same general analysis approach as the previous addendum . A model of the Beaver Valley Unit 2 electrical distribution system is created using ETAP. The ETAP transient stability module is used to simulate electrical transients caused by fast bus transfers , motor starts, etc. The results of these simulations are reviewed to establish equipment operating limits and confirm that calculation acceptance criteria are met.

Calculation Changes After the previous addendum was completed , the scope of plan ned undervoltage protection scheme changes expanded and some improvements were recommended following a third-party review. This addendum addresses the scope expansion and recommended improvements. This addendum differs from the previous addendum in that:

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1. The voltages at the secondary sides of the SSSTs are regulated . The previous addendum evaluated voltages based on fixed SSST tap positions.

2. Voltage decreases in the offsite power source caused by tripping the main unit generator are considered . The decreases are based on post-contingency voltage drop warning limits maintained by PJM.

3. The minimum allowable degraded voltage time delay is determined based on the times it takes the degraded voltage relays to reset following expected voltage transients . In contrast, the previous addendum verified that the degraded voltage relays reset within a predetermined time delay of six seconds.

4. This addendum accounts for SSST impedance variations with respect to tap position . The previous addendum utilized fixed impedance values regardless of tap position .

5. A study case that addresses block starting safety-injection equipment from the SSSTs during steady-state conditions (i.e. without fast bus transfers) is included.

6. Beyond-design-basis study cases from the previous addendum are omitted. These study cases involved block starting safety-injection equipment coincident with or shortly after fast bus transfers. Each case postulated an independent fast bus transfer and safety injection as opposed to a safety injection and consequential fast bus transfer. For the most credible safety-injection scenarios , safety-injection equipment starts from the unit station service transformers (USSTs) and is transferred to the SSSTs after a 30 second time delay.

7. A study case that addresses reactor coolant pump motor starting is included. This is necessary, because voltage settings for the loss of voltage relays are being increased. The reactor coolant pump motors yield the most severe motor starting transients.

8. A study case that addresses fast bus transfer from the SSSTs to the USSTs is included . This is necessary, because voltage settings for the loss of voltage relays are being increased .

9. In the previous addendum , the negative lumped loads used to model load diversity were not determined correctly.

This addendum rectifies this error. Section 7.8 of calculation 10080-E-068 Rev. 5 describes the general method for determining the negative lumped loads.

10. One charging pump is aligned to each safety-related 4160-volt bus. In the previous addendum , two charging pumps were aligned to each bus, which is an atypical alignment. Load diversity factors are adjusted to account for this change. (0.466 MW and 0.207 MVAR are added to each negative lumped load on buses 2AE and 2DF. These values correspond to the electrical load associated with one charging pump.)

Study Case Descriptions The SSST voltage regulation scheme is being modified such that the transformer taps are maintained in elevated positions when the transformers are unloaded. In the ETAP model, voltage regulation settings and tap positions are controlled using revisions. Each revision is described in the following table. Voltages are specified in terms of potential-transformer secondary voltages, wh ich differ from the primary voltages by a factor of 35. (The potential-transformer ratio is 4200/120).

Revision Description LTC-MAX-S This revision is based on existing voltage regulating relay (VRR) settings. The existing setting is 124.5 +/- 1.5 volts accounting for bandwidth and setting tolerances . The maximum voltage is therefore 126.0 volts. SSST taps are regulated such that the secondary-side voltages are at least 126.0 volts. This revision is used for maximum voltage conditions when buses are aligned to the SSSTs.

LTC-MIN-S This revision is based on existing VRR settings . The existing setting is 124.5 +/- 1.5 volts accounting for bandwidth and setting tolerances . The minimum voltage is therefore 123.0 volts . SSST taps are regulated such that the secondary-side voltages are at most 123.0 volts. This revision is used for minimum voltage conditions when buses are aligned to the SSSTs.

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10080-E-271 Revision Description LTC-MAX-U This revision is based on proposed VRR settings. The proposed setting is 128 +/- 1.5 volts accounting for bandwidth and setting tolerances. The maximum voltage is therefore 129.5 volts. SSST taps are regulated such that the secondary-side voltages are at least 129.5 volts. This revision is used for maximum voltage conditions when buses are aligned to the USSTs.

LTC-MIN-U This revision is based on proposed VRR settings. The proposed setting is 128 +/- 1.5 volts accounting for bandwidth and setting tolerances. The minimum voltage is therefore 126.5 volts. SSST taps are regulated such that the secondary-side voltages are at most 126.5 volts when the voltages at the 138-kV buses are 100 percent of the nominal voltage. The corresponding taps are then fixed , and the 138-kV bus voltage is reduced to 98.5 percent. This accounts for a 1.5 percent voltage drop caused by a unit trip . This revision is used for minimum voltage conditions when buses are aligned to the USSTs.

LTC-RCP-S This revision is identical to LTC-MIN-S . It was intended to facilitate manual SSST tap changes before starting a reactor coolant pump. However, voltage results using the minimum regulated tap setting were determined to be acceptable. Manual tap increases were therefore not considered.

LTC-SI-S This revision is based on existing VRR settings. The existing setting is 124.5 +/- 1.5 volts accounting for bandwidth and setting tolerances. The minimum voltage is therefore 123.0 volts. SSST taps are regulated such that the secondary-side voltages are at most 123.0 volts when the voltages at the 138-kV buses are 100 percent of the nominal voltage. The corresponding taps are then fixed , and the 138-kV bus voltage is reduced to 98.5 percent. This accounts for a 1.5 percent voltage drop caused by a unit trip. This revision is used for minimum-voltage, safety-injection conditions when buses are aligned to the SSSTs.

ETAP configurations are used to control breaker positions, which determine whether buses are aligned to offsite or onsite power and determine what motors are running for given scenario (e.g. normal operation , safety injection). Each configuration is described in the following table .

Configuration Description TS-S-NX This configuration is used for normal operation with buses aligned to the SSSTs. Non-safety-related 480-volt buses are not cross-tied.

TS-S-N2SI This configuration is used for study cases that involve a transition from normal operating conditions to safety-injection conditions. In contrast to the normal configuration , breakers associated with the low-head safety-injection pumps , auxiliary feedwater pumps , and leak collection system electric heaters are closed .

Additionally, switches associated with motor-operated valve (MOV) starting loads are closed . Using appropriate motor acceleration and switching events , relevant study cases are configured such that standby safety-injection equipment is not operating prior to accident initiation. Buses are aligned to the SSSTs.

TS-U-NX This configuration is identical to TS-S-NX except that buses are aligned to the USSTs.

TS-U-N2SI This configuration is identical to TS-S-N2SI except that buses are aligned to the USSTs.

ETAP study cases are summarized in the following table . Unit trip/safety injection/fast bus transfer scenarios that were previously split across two study cases have each been consolidated into one study case. Study cases have also been renamed to be more descriptive. For example , study case FBT-US-SL involves a fast bus transfer (FBT) from the unit station service transformers to the system station service transformers (US) for safety injection conditions with low voltages (SL) .

Study case FBT-SU-NH involves a fast bus transfer (FBT) from the system station service transformers to the unit station

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service transformers (SU) for normal operating conditions with high voltages (NH) . Cross-references to the former study case names are included in parenthesis .

Study Case Revision Configuration Description FBT-US-NH LTC-MAX-U TS-U-NX This study case evaluates a fast bus transfer from the USSTs to the SSSTs (23b) for maximum-voltage, non-accident conditions.

FBT-US-NL LTC-MIN-U TS-U-NX This study case evaluates a fast bus transfer from the USSTs to the SSSTs (23a) for minimum-voltage , non-accident conditions. A 1.5 percent decrease in the 138-kV bus voltage due to a unit trip is considered .

FBT-US-SH LTC-MAX-U TS-U-N2SI This study case evaluates a fast bus transfer from the USSTs to the SSSTs (7a , 7b) for maximum-voltage, safety-injection conditions . This case involves a turbine trip at t = 0 s, a safety injection at t = 10 s, and a fast bus transfer at t = 30 s.

The safety injection causes the high-head safety-injection pumps , low-head safety-injection pumps, auxiliary feedwater pumps, leak collection system electric heaters, and various MOVs to start. The MOV starting current is reduced to running current after 2 seconds . To yield worst-case motor starting transients, the high-head safety-injection pumps (which run during normal operation) are considered to start.

The safety injection causes the main feedwater pumps, control rod drive mechanism (CROM) fans , containment air recirculation (CAR) fans , and pressurizer heaters to trip .

FBT-US-SL LTC-MIN-U TS-U-N2SI This study case is similar to FBT-US-SH but addresses minimum-voltage (7a2 , 7b2) conditions. A 1.5 percent decrease in the 138-kV bus voltage due to a unit trip is considered .

FBT-US-FH LTC-MAX-U TS-U-NX This study case evaluates a fast bus transfer from the USSTs to the SSSTs (20b) following a fault on the high side of the main transformer. The fault is applied at t =Os; a fast bus transfer occurs at t = 0.067 s. This study case is performed for maximum-voltage conditions.

FBT-US-FL LTC-MIN-U TS-U-NX This study case evaluates a fast bus transfer from the USSTs to the SSSTs (20a) following a fault on the high side of the main transformer. The fault is applied at t = 0 s; a fast bus transfer occurs at t = 0.067 s. This study case is performed for minimum-voltage conditions. A 1.5 percent decrease in the 138-kV bus voltage due to a unit trip is considered.

FBT-SU-NH LTC-MAX-S TS-S-NX This study case evaluates a fast bus transfer from the SSSTs to the USSTs (14 , 15) for maximum-voltage, non-accident cond itions .

FBT-SU-NL LTC-MIN-S TS-S-NX This study case evaluates a fast bus transfer from the SSSTs to the USSTs for minimum-voltage, non-accident conditions.

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10080-E-271 Study Case Revision Configuration Description MS-RCP LTC-RCP-S TS-S-NX This study case evaluates starting the A reactor coolant pump under (1) minimum-voltage conditions. The A pump is selected , because it is upstream of safety-related bus 2AE. The other reactor coolant pumps are upstream of non-safety-related buses.

MS-SI LTC-SI-S TS-S-N2SI This study case evaluates starting safety-injection equipment from the SSSTs under minimum-voltage conditions. A 1.5 percent decrease in the 138-kV bus voltage due to a unit trip is considered .

The previous addendum included a load flow study case (LF-Min-Ld-S) that addressed maximum voltage, minimum load conditions . The changes incorporated into this addendum do not necessitate revisiting that study case .

Assumptions The minimum allowable degraded voltage time delay for accident conditions is based on the lengths of the voltage transients caused by block starting safety-injection equipment or by fast bus transfers . These transients are an expected consequence of a safety-injection signal. Some actions-such as manually starting a large 480-volt fan-can yield longer voltage transients .

For those transients not caused by automatic response to a safety-injection signal , it is assumed that procedural controls are sufficient to avoid unnecessary operation of the degraded voltage protection .

Acceptance Criteria Voltage Regulation Band for the SSSTs The SSST voltage regulation scheme is being modified such that the transformer taps are maintained in elevated positions when the transformers are unloaded. This ensures the degraded voltage relays reset following fast bus transfers-without crediting the load tap changers. This addendum establishes an acceptable voltage regulation band for the SSSTs. The minimum voltage is selected such that the degraded voltage relays reset following fast bus transfers. For the degraded voltage relays to reset, voltages at the safety-related 4160-volt and 480-volt buses shall recover above 94.14 percent of the nominal bus voltages. (Refer to the electrical protective device setting sheets for the degraded voltage relays: BV2-RBN-003, BV2-RBP-003, BV2-VBE-015, and BV2-VBF-015.)

From IEEE CS? .12.00, the maximum voltage on the secondary side of an unloaded transformer shall not exceed 110 percent of the voltage rating . Accordingly, the maximum voltage shall be less than 110 percent of 4360 volts (i .e. 4796 volts).

Minimum Allowable Degraded Voltage Time Delay This addendum determines the minimum allowable degraded voltage time delay for accident conditions. The minimum delay provides adequate time for the degraded voltage relays to reset following expected voltage transients caused by fast bus transfers or motor starts. The minimum time delay shall exceed the lengths of the voltage transients caused by block starting safety-injection equipment or by fast bus transfers-whichever is more limiting.

Maximum Allowable Dropout Voltage for the Loss of Voltage Relays Th is addendum determines maximum allowable dropout voltage for the loss of voltage relays . The maximum dropout voltage shall be less than the minimum voltage observed at the safety-related 4160-volt buses during reactor coolant pump starts .

Other Considerations Given the limits established above, the addendum demonstrates that overcurrent and undervoltage protection does not operate during expected voltage transients caused by fast bus transfers or motor starts . For the fast bus transfer study cases, the following criteria shall be met:

1. Upon breaker closure , motor currents shall not exceed the minimum instantaneous trip settings of the associated overcurrent relays.

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2. In accordance with ANSI C50.41 , the resultant volts-per-hertz (V/Hz) vector between the incoming source and the motor at the instant of transfer should not exceed 1.33 per unit volts per hertz on the motor rated voltage and frequency basis. In cases where this acceptance criterion is not met, additional analyses are documented in MPR calculations 0321-0117-CALC-001 and 0321-0117-CALC-003.

3. For accident conditions, voltages at the safety-related 4160-volt and 480-volt buses shall recover above 94.14 percent of the nominal bus voltages within the minimum allowable degraded voltage time delay established in this addendum .

4. Voltages at the safety-related 4160-volt buses should recover above 90 percent of the nominal bus voltage within 0.9 seconds. 0.9 seconds is the minimum time delay for the loss of voltage relays. The present reset setting for the loss of voltage relays is 81.53 percent. A higher voltage is used in this calculation to provide margin to increase the setting .

For the motor starting study cases involving a safety-injection , voltages should not drop below 92 percent at the safety-related 4160-volt and 480-volt buses. This ensures that the bus voltages remain within the bounds of the analyses in calculations 10080-E-221 and 10080-E-222 . These calculations demonstrate that motors have adequate voltage to start and run when bus voltages are near the degraded voltage relay dropout settings.

Computation ETAP output reports for each study case are included in attachments 1 through 10. Relevant voltage plots for all study cases are consolidated in Attachment 11. Motor currents during fast bus transfers are compared to overcurrent trip settings in Attachment 12. Volts-per-hertz values during fast bus transfers are shown in Attachment 13.

Terminal voltage, acceleration power, electrical power, mechanical power, and slip information for select safety-related fans is tabulated in Attachment 14; this information is used as an input to MPR calculation 0321 -0117-CALC-003.

Results The proposed voltage regulation band for the SSSTs is 128 +/- 1.5 volts. The maximum voltage of 129.5 volts (4532.5 volts) does not exceed 110 percent of the transformer voltage rating (4796 volts).

For the fast bus transfer study cases, recovery voltages following fast bus transfers are summarized in the table below. Only the minimum-voltage cases are included, because they are more limiting than the maximum-voltage cases . The voltage acceptance criterion is met in all cases, which confirms the adequacy of the proposed voltage regulation settings for the SSSTs. During fast bus transfers , the degraded voltage relays reset in less than 2.2 seconds.

Bus Voltage(%) Following Fast Bus Transfer (Acceptance Criterion> 94.14%)

Bus FBT-US-NL FBT-US-SL FBT-US-FL FBT-SU-NL 2AE 98 .62 99.69 98 .62 99.61 2DF 98 .70 99.70 98 .70 100.26 2N 94.27 97 .29 94 .27 95.29 2P 94.33 97.43 94.33 95.92 Relevant voltage plots for each study case are included in Attachment 11 . Based on a review of the plots , voltage transients associated with block starting safety-injection equipment subside within 2.2 seconds. 2.2 seconds is an acceptable minimum bound for the degraded voltage relay time delay during accident conditions .

The voltage at bus 2AE drops to 84.00 percent when starting the A reactor coolant pump under minimum voltage conditions .

84 percent is an acceptable maximum bound for the dropout voltage of the loss of voltage relays .

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Motor currents during fast bus transfers are compared to overcurrent trip settings in Attachment 12. The results show that overcurrent protective devices do not operate during fast bus transfers .

Volts-per-hertz values during fast bus transfers are tabulated in Attachment 13. The results show that the volts-per-hertz acceptance criterion is exceeded in many cases. Further analysis , which demonstrates the acceptability of the results , is available in MPR calculations 0321-0117-CALC-001 and 0321-0117-CALC-003.

Reset times for the loss of voltage relays during fast bus transfer are summarized in the following table. For conservatism , the relays are considered to drop out when the bus supply breakers open (or-for study case FBT-US-FL-when the fault occurs).

Only the minimum voltage cases are included , because recovery times in the maximum voltage cases are shorter. The acceptance criterion is met in all cases, which confirms that the loss of voltage relays do not operate during fast bus transfers .

Loss of Voltage Relay Reset Times (s) (Acceptance Criterion< 0.9 s)

Bus FBT-US-NL FBT-US-SL FBT-US-FL FBT-SU-NL 2AE 0.283 0.223 0.550 0.303 2DF 0.353 0.423 0.570 0.383 The minimum bus voltages when starting safety-injection equipment are confirmed to be greater than 92 percent. Results are summarized in the following table. Only the minimum-voltage cases are included, because they are more limiting than the maximum-voltage cases. The acceptance criterion is met in all cases , which confirms that voltages remain within the bounds of the analyses in calculations 10080-E-221 and 10080-E-222.

Minimum Bus Voltage (%) when Starting Safety-Injection Equipment (Acceptance Criterion > 92%)

Bus FBT-US-SL MS-SI 2AE 96.97 (at 10.201 s) 97.78 (at 1.221 s) 2DF 97 .55 (at 10.201 s) 97 .14 (at 1.211 s) 2N 92 .78 (at 10.301 s) 93 .57 (at 1.281 s) 2P 93 .84 (at 10.301 s) 93.44 (at 1.271 s)

Conclusions When the SSSTs are unloaded , the secondary-side voltages shall be regulated to within 128 +/- 1.5 volts.

For accident conditions , the degraded voltage relay time delay shall be greater than 2 .2 seconds. This provides adequate time for bus voltages to recover following fast bus transfers and is longer than the voltage transients associated with block starting safety-injection equipment. To minimize the potential for inadvertent relay actuation and to preserve operating margin , the time delay should be as long as permissible. (Refer to calculation 10080-E-346.)

The dropout voltage of the loss of voltage relays for the safety-related 4160-volt buses shall be less than 84 percent of the nominal bus voltage. This ensures that the relays do not drop out when starting large motors , such as the reactor coolant pump motors. To minimize the potential for inadvertent relay actuation and to preserve operating margin , the dropout setting

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10080-E-271 should be as low as permissible. (Refer to calculation 10080-E-346.) To be within the bounds of this analysis , the relay reset voltages shall not exceed 90 percent of the nominal bus voltage.

Except for the ANSI C50.41 volts-per-hertz limits, calculation acceptance criteria are met. Further analysis, which demonstrates the acceptability of the volts-per-hertz results, is available in MPR calculations 0321-0117-CALC-001 and 0321-0117-CALC-003.

Enclosure G L-22-081 Calculation No. 10080-E-271 , Revision 1, Addendum 7, "BVPS Unit-2 Transient Stability Analysis" (5 pages follow)

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10080-E-271 0 BV1 [8l BV2 0 BV1/2 0 BV3 0 BVSWT I 0 DB I 0 PY TITLE/

SUBJECT:

BVPS Unit-2 Transient Stability Analysis Classification : [8l Tier 1 Calculation I t8l Safety-Related/Augmented Quality ID Non-safety-Related Open Assumptions?: D Yes [8l No If Yes, Enter Tracking Number Initiating Document(s): CR 11-95145 (PY) Referenced in USAR Validation Database D Yes D No I (PY) Referenced in Atlas? D Yes D No Computer Program(s)

Program Name Version / Revision Category Status Description ETAP 11 .1.0N B Active ETAP is used to perform various types of electrical power analyses. In this calculation ,

the results of ETAP transient stability studies are used to evaluate the electrical system response to transients caused by fast bus transfers.

Originator ( P r i n ~ Reviewer/Design Verifier (Print, Sign & Date) Approver (Print, Sign & Date)

Michael Berg ~ '-1/~/,t Cory Murray -~ ~ ~ /s 11 f' Robert Lubert ,e~L ./. -v ~,1~11%

OBJECTIVE OR PURPOSE'ef ADDENDUM:

One of the calculation objectives is to demonstrate that undervoltage protection does not operate during expected voltage transients caused by fast bus transfers. Fast bus transfer scenarios were analyzed in the previous addendum . The results were used to confirm that fast bus transfers can be completed without unintended actuation of the degraded voltage protection . Bus voltages were compared to degraded voltage relay reset voltages to confirm that the relays reset following fast bus transfers. The information was used to select an appropriate voltage regulation band for the system station service transformers (SSSTs) when the transformers are unloaded .

It was subsequently identified that the reset voltages used in the calculation did not account for the accuracy of the calibration equipment. This addendum modifies the acceptance criterion for voltage reset to account for calibration accuracy. The results of the previous addendum are evaluated against the new acceptance criterion .

SCOPE OF ADDENDUM:

The acceptance criterion for degraded voltage relay reset is modified to account for calibration accuracy. The results of the previous addendum are evaluated against the new acceptance criterion. This addendum does not perform any new calculations .

LIST NEW DOCUMENTS TO BE ADDED TO THE DOCUMENT INDEX (DIN).

Q) 0 0 C z e! :5 z ~

Q) sa. a.

5 ci Document Number/Title Revision , Edition, Date 0:: E 0 10080-E-068, Station Service Voltage and Load Analysis Rev. 4

[8l 10080-DEC-0195, Setpoint Inaccuracy Calculation for Unit 2 Degraded Grid Rev. 0 [8l Relays 10080-DEC-0211, Beaver Valley Unit 2 - 4.16 kV Emergency Bus Rev. 1 [8l Undervoltage - Degraded Voltage 10080-DEC-0212, Beaver Valley Unit 2 - 480 Volt Emergency Bus Rev. 0 [8J Undervoltage - Degraded Voltage

Page 2 FtrstEne!f!Y CALCULATION ADDENDUM NOP-CC-3002-02 Rev. 07 CALCULATION NO.

10080-E-271 I ;ALCULATION REV. I ;ooENDUM NO.

SUMMARY

OF RESULTS/CONCLUSIONS OF ADDENDUM:

The degraded voltage relays reset following accident-initiated fast bus transfers. Reset times are within the minimum allowable degraded voltage time delay. The previously established voltage regulation band for the SSSTs is adequate .

When the SSSTs are unloaded, the secondary-side voltages shall be regulated to within 128 +/- 1.5 volts.

LIMITATIONS OR RESTRICTIONS CREATED BY ADDENDUM :

This addendum does not create new limitations or restrictions .

IMPACT OF ADDENDUM ON OUTPUT DOCUMENTS:

This addendum does not affect any output documents.

DESCRIBE WHERE THE ADDENDUM WILL BE EVALUATED FOR 10CFR50.59 / 10CFR72.48 APPLICABILITY:

Addendum 4 to Revision 1 of the calculation was evaluated for 10CFR50 .59 applicability in RAD and screen forms 15-01516. The previous evaluation still applies .

LIST SUPPORTING DOCUMENTS: (Include total number of pages)

Refer to the Table of Contents.

LIST ATTACHMENTS (Include total number of pages)

Refer to the Table of Contents .

Page 3 F,~ CALCULATION ADDENDUM I I NOP-CC-3002-02 Rev. 07 CALCULATION NO. ;ALCULATION REV. ;ooENDUM NO .

10080-E-271 Table of Contents Section Title Cover 1 Table of Contents 3 Background/Objective 4 Design Inputs 4 Method of Analysis 4 Assumptions 4 Acceptance Criteria 4 Computation 4 Results 5 Conclusions 5 Subtotal 5 Pages Attachment 2 Transient Stability Analysis Report - Study Case FBT-US-NL 367 Pages Attachment 4 Transient Stability Analysis Report - Study Case FBT-US-SL 490 Pages Attachment 6 Transient Stability Analysis Report - Study Case FBT-US-FL 396 Pages Attachment 8 Transient Stability Analysis Report - Study Case FBT-SU-NL 370 Pages Attachment 11 Voltage Plots from Transient Stability Study Cases 9 Pages Design Verification Record 1 Page Calculation Review Checklist 3 Pages Design Interface Summary 9 Pages Subtotal 1645 Pages Total 1650 Pages

Page 4 Ftrstl;ne!@' CALCULATION ADDENDUM I I NOP-CC-3002-02 Rev. 07 CALCULATION NO. ~ALCULATION REV. ;DDENDUM NO.

10080-E-271 Background/Objective One of the calculation objectives is to demonstrate that undervoltage protection does not operate during expected voltage transients caused by fast bus transfers . Fast bus transfer scenarios were analyzed in the previous addendum . The results were used to confirm that fast bus transfers can be completed without unintended actuation of the degraded voltage protection . Bus voltages were compared to degraded voltage relay reset voltages to confirm that the relays reset following fast bus transfers. The information was used to select an appropriate voltage regulation band for the system station service transformers (SSSTs) when the transformers are unloaded.

It was subsequently identified that the reset voltages used in the calculation did not account for the accuracy of the calibration equipment. This addendum modifies the acceptance criterion for voltage reset to account for calibration accuracy. The results of the previous addendum are evaluated against the new acceptance criterion.

Design Inputs The maximum reset voltage of 95.3 percent for the degraded voltage relays was obtained from calculation 10080-E-068 Rev. 4, page 11 (page 1672 of the PDF file). The reset voltage is based on relay accuracy information in calculation 10080-DEC-0195, which has since been superseded by calculations 10080-DEC-0211 and 10080-DEC-0212. The reset voltage from 8700-E-068 was carried into those calculations as the high safety-analysis limit, which makes it an appropriate value to use in this calculation .

Method of Analysis ETAP results from the previous addendum are reviewed to confirm that the degraded voltage relays reset following accident-initiated fast bus transfers. The time to reset is verified to be less than the minimum allowable degraded voltage time delay.

Assumptions There are no new assumptions .

Acceptance Criteria The SSST voltage regulation scheme is being modified such that the transformer taps are maintained in elevated positions when the transformers are unloaded. For accident conditions, this ensures the degraded voltage relays reset following fast bus transfers-without crediting the load tap changers. This addendum confirms that the previously established voltage regulating band allows degraded voltage relays to reset following accident-initiated fast bus transfers. To achieve reset, voltages at the safety-related buses shall recover to greater than 95.3 percent of the nominal bus voltage. Reset shall be achieved within the minimum allowable degraded voltage time delay of 2.2 seconds established in the previous addendum .

For the non-accident cases , it is less critical that the degraded voltage relays reset immediately following fast bus transfer. In those cases, credit may be taken for the 90-second non-accident degraded voltage time delay and the load tap changers . The load tap changers operate after an initial 30-second time delay, and each tap change takes approximately 2 seconds.

Computation ETAP results from study cases FBT-US-NL, FBT-US-SL, FBT-US-FL, and FBT-SU-NL are included in attachments 2, 4 , 6, and 8, respectively. Attachment 11 contains relevant voltage plots . The information in these attachments is unchanged from the previous addendum .

Page 5 FtrstEoe!Jrl CALCULATION ADDENDUM I I NOP-CC-3002-02 Rev. 07 CALCULATION NO. ~ALCULATION REV. ;ooENDUM NO.

10080-E-271 Results Recovery voltages following fast bus transfers are summarized in the table below. Only the minimum-voltage cases are included, because they are more limiting than the maximum-voltage cases. The voltage acceptance criterion is met in the safety-injection case, which confirms the adequacy of the proposed voltage regulation settings for the SSSTs. The degraded voltage relays reset in less than 2.2 seconds.

Bus Voltage(%) Following Fast Bus Transfer (Acceptance Criterion> 95.3%, FBT-US-SL only)

Bus FBT-US-NL FBT-US-SL FBT-US-FL FBT-SU-NL 2AE 98.62 99.69 98.62 99 .61 2DF 98 .70 99.70 98.70 100.26 2N 94.27 97 .29 94.27 95.29 2P 94 .33 97.43 94.33 95 .92 Conclusions The degraded voltage relays reset following accident-initiated fast bus transfers. Reset times are within the minimum allowable degraded voltage time delay. The previously established voltage regulation band for the SSSTs is adequate. When the SSSTs are unloaded, the secondary-side voltages shall be regulated to within 128 +/- 1.5 volts.

Enclosure H L-22-081 Calculation No. 8700-DEC-0212, Revision 2, "Beaver Valley Unit 1 4.1 kV Emergency Bus Undervoltage: Trip Feed and Start Diesel Uncertainty Calculations" (13 pages follow)

Page i ArstEne!@' CALCULATION NOP-CC-3002-01 Rev . 05 CALCULATION NO. VENDOR CALCULATION NO. NIA 8700-DEC-0212 181 BV1 D BV2 0 BV1/2 BV3 0 BVSWT I 0 DB I 0 PY Title/

Subject:

Beaver Valley Unit 1 4 .1 kV Emergency Bus Undervoltage : Trip Feed and Start Diesel Uncertainty Calculations Category: 181 Active I D Historical I D Study Vendor Cale Summary: Yes D No 181 Classification: 181 Tier 1 Calculation 181 Safety-Related/Augmented Quality I Non-safety-Related Open Assumptions?: D Yes 181 No If Yes, Enter Tracking Number System Number: 36 Functional Location : 27 -VE100, 27-VE1100, 27-VF100, 27-VF1100 Commitments: None Initiating Documents: CR11-95145 (PY) Calculation Type:

(PY) Referenced In USAA Validation Database D Yes O No I (PY) Referenced In Atlas? D Yes O No Computer ProQram(s)

Program Name Version I Revision Category Status Description WORD Office 2010 C Active Word Processing EXCEL Office 2010 C Active Spreadsheet, Calculations Revision Record Originator Reviewer/Design Verifier Approver Rev. Attected Pages Print, Si n & Date Print, Si n & Date Print, Si n & Date 2 Sections 1.0 J. Nydes  ?-Ji-I~ D. Martin 7-)P-H? D. Stittler 7--fl-18 f)J/~ (?{)

through 6.3 of Rev . 0 calculation J-Af.

Description of Change: The purpose of this revision is to remove/void RAD 18-00472 that was documented in Rev . 1 of this calculation which is to be superseded In Its entirety. The BV1 4.1 kV Emergency Bus (Trip Feed, Emergency Diesel Generator Start)

Channel Statistical Allowance (CSA) uncertainty is established as a result of calculation 8700-DEC-0212 Rev. 2. For the purposes of this calculation, there are no impacts to any plant operations or procedures . The provisions of 10CFR50.59 do not apply to this calculation and a RAD and Screen are not required .

For future BV1 4.1kV Emergency Bus degraded vol!age modifications where this uncertainty calculation will be an input to future associated setting changes, 10CFRS0.59 applicability will be addressed in ECP-18-0054 via Screen 18-004 78 for BV 1.

Describe where the calculation will be evaluated for 10CFR50.59 and/or 10CFR72.48 applicability. 10CFR50.59 is not required .

(see 'Description of Change' above) and 10CFR72.48 is not applicable.

Page ii F1rstEne!JlY CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. [] VENDOR CALC

SUMMARY

8700-DEC-0212 Rev. 2 VENDOR CALCULATION NO. N/A TABLE OF CONTENTS SUBJECT PAGE COVERSHEET: i OBJECTIVE OR PURPOSE iii SCOPE OF CALCULATION iii

SUMMARY

OF RESULTS/CONCLUSIONS iii LIMITATIONS OR RESTRICTION ON CALCULATION APPLICABILITY iii IMPACT ON OUTPUT DOCUMENTS iii DOCUMENT INDEX (DIN) iv CALCULATION COMPUTATION (BODY OF CALCULATION)

METHOD OF ANALYSIS 1 ASSUMPTIONS 1 ACCEPTANCE CRITERIA 1 COMPUTATION 2 RESULTS 8 CONCLUSIONS 8 ATTACHMENTS : NIA SUPPORTING DOCUMENTS (For Records Copy Only)

DESIGN INTERFACE

SUMMARY

8 Pages DESIGN VERIFICATION RECORD 1 Pages CALCULATION REVIEW CHECKLIST 3 Pages TOTAL NUMBER OF PAGES IN CALCULATION (COVERSHEETS +BODY+ ATTACHMENTS) 13 Pages

Page iii FlrstEne!@' CALCULATION NOP*CC-3002-01 Rev. 05 CALCULATION NO.

[ ] VENDOR CALC

SUMMARY

8700-DEC-0212 Rev. 2 VENDOR CALCULATION NO. N/A OBJECTIVE OR PURPOSE:

The objective of this calculation is to document the calculation of instrumentation uncertainties for the BV1 4.1 kV Emergency Bus Undervoltage functions {Trip Feed, Emergency Diesel Generator Start) .

SCOPE OF CALCULATION:

The original issue of this calculation was created by Westinghouse {identified as CN -SSO-99-50 Revision 0).

The scope of this calculation is to revise the BV1 4.1kV Emergency Bus Undervoltage (Trip Feed, Emergency Diese l Generator Start) relay Channel Statistical Allowance {CSA) uncertainty calculation and Allowable Value

{AV) calculation based on a revised {statistically calculated) relay drift value that was determined as per 10080-DEC-0222 Rev 1, "Beaver Valley Units 1 and 2 Drift Evaluation Results for ATS/ES FAS Relay Instrumentation" (DIN, Item 2).

This calculation also incorporates a revised Nominal Trip Setpoint (NTS) as determined by DIN Item 6 for the relays identified under Functional Locations on the calculation coversheet, Page i.

The main changes incorporated in and resulting from th is calculation revision are:

a revised relay channel uncertainty based on a revised relay drift uncertainty (DIN , Item 2) a revised Nominal Trip Setpoint determined by FENOC (DIN , Item 6) a revised Allowable Value (based on revised NTS and revised relay drift uncertainty) relay channel Total Allowance and Margin calculations based on relay Analytical Limits {AL) determined by FENOC (DIN, Item 6)

SUMMARY

OF RES ULTS/CONCLUSIONS:

In support of BV1 4.1kV Emergency Bus Undervoltage relay calibrations, the Maintenance Measured Database (MMD) process and 10080-DEC-0222 Rev. 1 (DIN , Item 2), a revised channel uncertainty of 3.0 volts secondary, 105.0 Vac Bus and an AV of 77.5%, 3224 .0 Vac Bus , 92.1 volts secondary have been determined based on a revised relay drift uncertainty and a revised NTS. Note that the resulting channe l uncertainty is calculated in volts (as opposed to'% span' in previous calculations) in support of initiatives to better define operating parameters for the undervoltage relays .

The revised NTS is 78.5%, 3266 Vac Bus, 93.3 volts, secondary.

The results of this calculation revision will be used to update MSPs, re lay scaling ca lculations and Tech nical Specificat ions.

LIM ITATIONS OR RESTRICTIONS ON CALCU LATION APPLICABILIT Y:

The re sults of this calculat ion are applicabl e to the specific BV 1 4.1l<V Emerg ency Bu s Undervoltage re lays identifi ed under Functional Locations on the calculation co ve rsheet, Page i.

Shou ld the "As-Found" 4.1 kV Emergency Bus Undervoltage re la y drift exceed the MMD values du ring any calibration frequency, a Condition Report (CR) is to be initiated, as is the practice in MMD excessive drift.

IMPACT ON OUTPUT DOCUMENTS:

The BV1 4. 1kV Emergency Bus Undervoltage channe l uncert ai nty and allowable valu e calculations have been revised as a res ult of this calculation revision. The calcu lation results are used as input to the Maintenance/Surve illance Proce dures (MS P) and the relay scaling calc ula tions identifi ed in the Docum ent Index list ing of this calculation.

Page iv F1rstEn~ CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. [ } VENDOR CALC

SUMMARY

8700-DEC-0212 Rev. 2 VENDOR CALCULATION NO. N/A DOCUMENT INDEX Q) ci u z C:

5 :5 z

!;) 0. .E-Document Numberrritle Revision, Edition, Date Q) o:; E 0 i5 a:

1 8700-DEC-0212, Beaver Valley Unit 1 4.1kV Revision 0 l'8l Emergency Bus Undervoltage : Trip Feed and Start Diesel Uncertainty Calculations 2 10080-DEC-0222, Beaver Valley Units 1 and 2 Revision 1 l'8l Drift Evaluation Results for RTS/ESFAS Relay Instrumentation 3 Beaver Valley Unit 1 Licensing Requirements Revision 99 l8l Manual 4 Beaver Valley Units 1 and 2 Technical Amendments 299, Unit 1, 8/2/ 17 l8l Specifications, Table 3.3.5-1 188, Unit 2, 8/2/17 5 8700-05 .010-0018 Revision A l8l WCAP-11419-P Rev. 6, Westinghouse Setpoint Methodology for Protection Systems - Beaver Valley Power Station Unit 1 6 ND1MDE:0718 DIT-BVDM-010 1-00, Revision 0 l8l Transmittal of Analytical Limits and Nominal Trip Setpoints for BV1 and BV2 Loss of Voltage Relays (L VRs) and New Degraded Voltage Relay (OVA) Timers 7 8700-DEC-0228, Determination of Relay Revision O 0

Scaling Voltages for Unit 1 Technical Specifications Tables 3.3- 1, 3.3-3 and LAM Tables 3.9-1 , 3.9-2 8 1MSP-36.45E, 1AE 4kV Emergency Bus Loss Revision 26 l'8l Of Voltage Relay 27-VE1 00 Functional Test 9 1MSP-36 .46-E, 1OF 4kV Emergency Bus Loss Revision 25 l8l Of Voltage Relay 27-VF100 Functionol Te st 10 1MS P-36.47A-E, 1AE 4kV Emergency Bus Revision 13 l8l Loss Of Voltage Relay 27- VE100 Calibration 11 1MS P-36.48A-E, 1DF 4k V Emergency Bus Revision 17 D [8J Loss of Vollage Re lay 27*V F100 Calibration 12 1MSP-36.53A-E, 1AE 4kV Eme rgency Bus Revision 12 D ID l8l Diesel Start Undervoltage Relay 27 -VEl 100 18 i Month Calibrati on  !

i 13 1MSP-36.54A- E, 1OF 4kV Emergency Bus Revision 13 0 D ~

Diesel Start Un dervoltage Rela y 27 -VF1100 '

i Calibration I i

14 1MSP-36.55-E, 1AE 4kV Emergency Bus Revision 22 I l8l Diesel Start Loss ot Vo ltage Relay 27-VE1100 I Functional Test I -----

Page v ArstEne!W CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. [] VENDOR CALC

SUMMARY

8700-DEC-0212 Rev. 2 VENDOR CALCULATION NO. NIA 15 1MSP-36.56-E, 1DF 4kV Emergency Bus Revision 24 D 18]

Diesel Start Loss of Voltage Relay 27-VFl 100 Functional Test

Page 1 of B flrstEne.!J!V CALCULATION COMPUTATION NOP-CC-3002*01 Rev . 05 CALCULATION NO.: REVISION :

8700-DEC-0212 2 METHOD OF ANALYSIS The basic uncertainty determination methodology used in this calculation note is the Square Root Sum of the Squares (SASS). As documented in Revision O of this calculation note (Westinghouse calculation CN-SSO-99-50 Rev. 0), the Westinghouse methodology combines the uncertainty components for a channel in an appropriate combination of those groups which are statistically and functionally independent. Those uncertainties which are not independent are treated by arithmetic summation and then combined via SASS with the independent terms.

WCAP-11419 (DIN, Item 5) provides a discussion in Section 2.0 regarding the Westinghouse methodology.

ASSUMPTIONS There are no assumptions associated with this calculation.

ACCEPTANCE CRITERIA In the original uncertainty calculation for the BV1 4.1 kV Emergency Bus Undervoltage relays function performed by Westinghouse, there was no Safety Analysis Limit (SAL) assumed by Westinghouse analyses groups and therefore no explicit acceptance criteria was defined. FE NOC was responsible for the determination of acceptability of the calculated uncertainties relative to any operational limits.

FENOC has now determined an Analytical Limit and a revised NTS for the relays identified in this calculation under Functional Location on Page i. Pe r DIN, Item 6, an Analytical Limit of 75.5% of 4160 volts and a revised NTS of 78.5% of 4160 volts have been documented. Based on the calculated CSA, there shou ld be positive margin between the Analytical Limit and the NTS.

Page 2 of 8 FtrstEne.!J!Y CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

8700-DEC-0212 2 COMPUTATION 4.1 kV Emergency Bus Undervoltage -Trip Feed and Start Diesel.

Undcrvoltagc Rela ys: > ABB Type 47H Model 2 1 INOl71 (Section 6.2*)

> Relay Models 21 IN017I. 412NOl75 (Reference DIN. Item 2; see Calculation Computation, page 17, 'Results')

(27-VEIOO. 27-VF!OO, 27-VEI 100, 27-VFl 100)

Item/Tenn and Value Descrip_tion Reference Sec. volb 120 volts Secondary-side volts. based on relay upper limit/rating Attachment List, Item 3 (08700-01.050-0152 Rev .

D)*

PT Turn ~ 35 Turns ratio of potential transformer, 35: 1 Reference 3*

BUS volts 4200 Vac Bus Bus voltage, 120 volts x PT Turns ratio (nominal 4160 volts)

Page 3 of B FirstEnergy CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION :

8700-DEC-0212 2 Note: The original Westinghouse uncertainty calcu lation (Rev_ 0) based the instrument span on the nominal 4160 volt bus voltage bei ng the upper span limit. In reality. the 120 volt secondary PT voltage relates at a 35: I ratio to a bus voltage of 4200 volts. In support of ini tiatives lo belier define operating parameters for the undervoltage relays and to eliminate any confusion with regards to span s_ upper limits. dala rernrding or evaluations, the CSA below is calculated based on 120 volt secondary and 4200 Yac Bus vo ltages. Per the calculation inputs in DIN Item 6 for the Analytical Limit and NTS, the TA. Margin and AV calculations are based on the nominal Yac Bus voltage of 4 I 60 volts.

NTS 78.5% Nominal Trip Setpoint % (% of 4160 volts), 3266 Yac Bus Reference DlN, Item 6 (93 .3 volts secondary-side, see Page 7 of 8)

SAL NIA Safety Analysis Li mil - No value was assumed by Westinghouse in Rev. 0 References 4*, 5*, 14* ,

calculation. (see ALmin below for current Analytical limit determined by FENOC) 15*. 16*, 17*

ALrnin 75 .5% Analytical Limit MlN % (% of 4160 volts) Reference DlN, Item 6

Page4 of 8 FirstEnergy

• - ~

CALCULATION COMPUTATION NOP-CC-3002-01 Rev . 05 CALCULATION NO.: REVISION:

8700-DEC-0212 2 Instrument Uncertainties:

Tenn  % Sec. volts PEA! 0.30% 0.36 Primary Element Accuracy Reference IO*

Potential transformer accuracy: turns ratio (0.3%)

PEA 2 0.25% 0.30 Primary Element Accuracy Reference IO*

Variation in dropout voltage vs. DC control (0.25% per 10% change)

RRA 0.50 Relay Repeatability (0.5 volts, secondary-side) Reference I 0*

RCA 0.50 Relay Calibration Accuracy (0.5 volts, secondary-side) Reference l O*

RMTE 0 .23% 0.28 Relay M&TE Accuracy, Fluke 8600A References 3*, IO*, 11

• Per Fluke 8600A specification (Reference I I*):

AC Voltage, 2, 20 and 200 volt ranges 0.2% of input+ 0.015% of range 0.2%

• 120 volts+ 0.015%

• 200 volt range= 0.27 volts 0.27 I 120 volts= 0.23%

RTE 2.00% 2.40 Relay Temperature Effect (2% variation over -20 to +55"C) Reference I 0*

RD 1.00% l.20 Relay Drift ( 1.0%) Reference DIN, Item 2

Page 5 of 8 FirstEnergy CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. : REVISION:

8700-DEC-0212 2

• ' Reference/Information identified in 8700-DEC-0212 Rev . 0 (W calculation CN-SSO-99-50 Rev. 0)

(Reference DIN. Item I)

Reference DTN, Item 2: I 0080-DEC-0222 Rev. I. "Beaver Valley Units I and 2 Drift Evaluation Results for RTS/ESFAS Relay Instrumentation" (See Calculation Computation, page 17,

'Results' for Relay Models 211 NO 171, 412N0 175)

Channel Statistical Allowance (CSA) Uncertainty Calculation CSA= [PEA 12 + PEA2 2 + RRA 2 + (RMTE + RCA)2 + (RMTE +RD/+ RTE 2]°

+/- 3.00 vol ts, secondary-side

.._ 105.0 Vac Bus (volts, secondary-side x PT Turns)

Page 6 of 8 FtrstEnergy CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 C/\LCUL/\TION NO.: REVISION:

8700-DEC-0212 2 TotaL_Allowance rTA l Calculation TAmin = IALmin -NTSI 3.0%

3.57 volts, secondary-side (Vac Bus/ PT Turns) 124.8 Vac Bus (of nominal 4160 volts)

Margin Calculation Margin = TAmin -CSA 0.57 volts. secondary-side (Vac Bus/ PT Turns) 19.8 Vac Bus (of nominal 4160 volts)

Page 7of 8 FirstEnergy CALCULATION NO.:

CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 REVISION:

8700-OEC-0212 2 Allowab le Value rAVl Calculation AV= NTS - RD 77.5%

92. 1 volts, secondary-side (Vac Bus/ PT Turns) 3224.0 VacBus (ofnominal4160volts)

NTS Secondary-side Voltage Calculation NTS-= 3266 Vac Bus Reference DIN, Item 6 Secondary-side voltage= Vac Bus/ PT Turns 93 .3 volts. secondary-s ide

Page 8 of 8 FlrstEne~ CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. : REVISION.

8700-DEC-0212 2 RESULTS In support of calibration of the BV1 4.1 kV Emergency Bus Undervoltage relays and the Maintenance Measured Database (MMD) process/10080-DEC-0222 Rev. 1 (DIN, Item 2), a revised channel uncertainty of 3.0 volts secondary (105 .0 Vac Bus) and an AV of 77 .5% (3224.0 Vac Bus, 92.1 volts, secondary) have been determined based on a revised relay drift uncertainty and a revised NTS (DIN, Item 6). Note that the resulting channel uncertainty is calculated in volts (as opposed to '% span' in previous calculations) in support of plant initiatives to better define operating parameters for the undervoltage relays.'

The AV is based on the revised NTS and the rack uncertainty (in this case the relay drift uncertainty). This is a reasonable approach based on the typical plant approach to drive the relay calibration tolerance to near zero.

The revised NTS is 78.5%, 3266 Vac Bus, 93.3 volts, secondary.

The revised NTS has been evaluated with respect to the relay Analytical Limits defined in FENOC calculations (DIN, Item 6). The Total Allowance (TA) was calculated to be 3.57 volts secondary, 124.8 Vac Bus while the resulting Margin was 0.57 volts secondary, 19.8 Vac Bus.

CONCLUSIONS This calculation revision is based on what is described in the 'Scope of Calculation' section. Given the acceptable results shown above, this lnformation will be used to update MSPs, relay scaling calculations and Technical Specifications.

Enclosure I L-22-081 Calculation No. 10080-DEC-0215, Revision 2, "Beaver Valley Unit 2 4.1 kV Emergency Bus Undervoltage: Trip Feed and Start Diesel Uncertainty Calculations"

( 14 pages follow)

Page i FtrstEn~ CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. VENDOR CALCULATION NO. N/A 10080-DEC-0215 0 BV1 181 BV2 _0 BV1/2 _ 0 _BV3 0 BVSWT I 0 DB I D PY Title/

Subject:

Beaver Valley Unit 2 4.1 kV Emergency Bus Undervoltage : Trip Feed and Start Diesel Uncertainty Calculations Category: ~ Active IO Historical ID Study Vendor Cale Summary: Yes D No~

Classification: ~ Tier 1 Calculation ~ Safety-Related/Augmented Quality I Non-safety-Related Open Assumptions?: D Yes ~ No If Yes, Enter Tracking Number System Number: 36 Functional Location : 27-VE200, 27-VE1200, 27-VE2200, 27-VF200, 27-VF1200, 27-VF2200 Commitments: None Initiating Documents: CR 11-95145 (PY) Calculation Type:

(PY) Referenced In USAA Validation Database 0 Yes D No J (PY) Referenced In Atlas? D Yes O No Computer Program(s)

Program Name Version/ Revision Category Status Description WORD Office 201 o C Active Word Processing EXCEL Office 2010 C Active Spreadsheet, Calculations Revision Record Originator Reviewer/Design Verifier Approver Rev. Affected Pages Print, Si n & Date (Print, Si n & Date 7 - ,i- I r Print, Sion & Date 2 Sections 1.0 J . Nydes --r- I! -/ '( o Martin through 6.3 of Rev. o calculation c1,,,._ 12. ,. IL .0Jj.~

Description of Change: The purpose of this revision is to remove/void RAD 18-00474 that was documented in Rev. 1 of this calculation which is to be superseded in its entirety. The BV2 4 .1kV Emergency Bus (Trip Feed, Emergency Diesel Generator Start)

Channel Statistical Allowance (CSA) uncertainty is established as a result of calculation 10080-DEC -0215 Rev . 2. For the purposes of this calculation , there are no impacts to any plant operations or procedures . The provisions of 10CFRS0.59 do not appfy to this calculation and a RAD and Screen are not required.

For future BV2 4 .1kV Emergency Bus degraded voltage modifications where this uncertainty calculation will be an input to future associated setting changes, 10CFR50.59 applicability will be addressed In ECP-18-0055 via Screen 18-00476 for BV2.

Describe where the calcu lation will be evaluated tor 10CFR 50.59 and/Dr 10CFR72 .4B applicability. 10CFR 50.59 is not required.

(see 'Description of Change' above) and 10CFR72.48 is not applicable.

Page ii ArstEne.!JlY CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.

[] VENDOR CALC

SUMMARY

10080-DEC-0215 Rev. 2 VENDOR CALCULATION NO. N/A TABLE OF CONTENTS SUBJECT PAGE COVERSHEET: i OBJECTIVE OR PURPOSE iii SCOPE OF CALCULATION iii

SUMMARY

OF AES ULTS/CONCLUSIONS iii LIMITATIONS OR RESTRICTION ON CALCULATION APPLICABILITY iii IMPACT ON OUTPUT DOCUMENTS iv DOCUMENT INDEX (DIN) V CALCULATION COMPUTATION (BODY OF CALCULATION):

METHOD OF ANAL VSIS 1 ASSUMPTIONS 1 ACCEPTANCE CRITERIA 1 COMPUTATION 2 RESULTS 8 CONCLUSIONS 8 ATTACHMENTS: NIA SUPPORTING DOCUMENTS (For Records Copy Only)

DESIGN INTERFACE

SUMMARY

9 Pages DESIGN VERIFICATION RECORD 1 Pages CALCULATION REVIEW CHECKLIST 3 Pages TOTAL NUMBER OF PAGES IN CALCULATION (COVERSHEETS + BODY+ ATTACHMENTS) 14 Pages

Page iii Ftrsl:Ene!JlY CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. [ ) VENDOR CALC

SUMMARY

10080-0EC-0215 Rev. 2 VENDOR CALCULATION NO. N/A OBJECTIVE OR PURPOSE:

The objective of this calculation is to document the calculation of instrumentation uncertainties for the BV2 4.1kV Emergency Bus Undervoltage functions (Trip Feed, Emergency Diesel Generator Start).

SCOPE OF CALCULATION:

The original issue of this calculation was created by Westinghouse (identified as CN-SSO-99-51 Revision 0) .

The scope of this calculation is to revise the BV2 4.1kV Emergency Bus Undervoltage (Trip Feed, Emergency Diesel Generator Start) relay Channel Statistical Allowance (CSA) uncertainty calculation and Allowable Value (AV) calculation based on a revised (statistically calculated) relay drift value that was determined as per 10080-DEC-0222 Rev 1, "Beaver Valley Units 1 and 2 Drift Evaluation Results for RTS/ESFAS Relay Instrumentation" (DIN, Item 3).

This calculation also incorporates a revised Nominal Trip Setpoint (NTS) as determined by DIN Item 7 for the relays identified under Functional Locations on the calculation coversheet, Page i. Note that 27-VE1200 and 27-VF1200 were not listed on the Rev. 0 coversheet but they are included in this calculation (see DIN Items 3 and 7).

The main changes incorporated in and resulting from this calculation revision are:

a revised relay channel uncertainly based on a revised relay drift uncertainty (DIN, Item 3) a revised Nominal Trip Setpoint determined by FENOC (DIN, Item 7) a revised Allowable Value (based on revised NTS and revised relay drift uncertainty) relay channel Total Allowance and Margin calculations based on relay Analytical Limits (AL) determined by FENOC (DIN, Item 7)

SUMMARY

OF RESULTS/CONCLUSIONS:

In support of BV2 4.1 kV Emergency Bus Undervoltage relay calibrations, the Maintenance Measured Database (MMD) process and 10080-DEC-0222 Rev. 1 (DIN, Item 3), a revised channel uncertainty of 3.0 volts secondary, 105.0 Vac Bus and an AV of 80.0%, 3328.0 Vac Bus, 95.1 volts secondary have been determined based on a revised relay drift uncertainty and a revised NTS. Note that the resulting channel uncertainty is calculated in volts (as opposed to '% span' in previous calculations) in support of initiatives to better define operating parameters for the undervoltage relays .

The revised NTS is 81%, 3370 Vac Bus, 96.3 volts, secondary.

The results of this calculation will be used to update MSPs, relay scaling calculations and Technical Specifications.

LIMITATIONS OR RESTRICTIONS ON CALCULATION APPLICABILITY:

The results of this calculation are applicable to the specific BV2 4.1 kV Emergency Bus Undervoltage relays identified under Functional Locations on the calculation coversheet, Page i.

Shou ld the "As-Found 4.1kV Emergency Bus Undervoltage relay drif t exceed the MMD values during any calibration frequency, a Condit ion Report (CR ) is to be initiated , as is the practice in MMD excessive drift.

Page iv ArstEne!JlY CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. [] VENDOR CALC

SUMMARY

10080-DEC-0215 Rev. 2 VENDOR CALCULATION NO. NIA IMPACT ON OUTPUT DOCUMENTS:

The BV2 4.1 kV Emergency Bus Undervoltage channel uncertainty and allowable value calculations have been revised as a result of this calculation revision . The calculation results are used as input to the Maintenance/Surveillance Procedures (MSP) and the relay scaling calculations identified in the Document Index listing of this calculation.

Page v FustEne!JlY CALCULATION NOP*CC-3002-01 Rev. 05 CALCULATION NO.

[ ) VENDOR CALC

SUMMARY

10080-DEC-0215 Rev. 2 VENDOR CALCULATION NO. NIA DOCUMENT INDEX Q) 0 0

5 z C

5 0..

z ~ 0..

5 ci Document Number/Title Revision, Edition, Date Cl>

<ii II:

-= 0 1 10080-DEC-0215, Beaver Valley Unit 2 4.1kV Revision 0 D [81 Emergency Bus Undervoltage: Trip Feed and Start Diesel Uncertainty Calculations 2 10080-DEC-0215, Beaver Valley Unit 2 4.1kV Revision 0, Addendum 1 D [8)

Emergency Bus Undervoltage: Trip Feed and Start Diesel Uncertainty Calculations 3 10080-DEC-0222, Beaver Valley Units 1 and 2 Revision 1 D [81 Drift Evaluation Results for RTS/ESFAS Relay Instrumentation 4 Beaver Valley Unit 2 Licensing Requirements Revision 90 D [81 Manual 5 Beaver Valley Units 1 and 2 Technical Amendments 299, Unit 1, 8/2/17 D 181 Specifica1ions, Table 3.3.5-1 188, Unit 2, 8/2/17 6 2220 .100-001-176 Revision A [81 WCAP-11366-P Rev. 7, Westinghouse Setpoint Methodology for Protection Systems

• Beaver Valley Power Station Unit 2 7 ND1 MDE:0718 DIT-BVDM-0 101-00, Revision 0 [81 Transmittal of Analytical Limits and Nominal Trip Setpoints for BV1 and BV2 Loss of Volt;ige Relays (LVRs) and New Degraded Vollage Relay (DVR) Timers 8 10080-DEC-0229, Determination of Relay Revision 0 [81 Scal ing Voltages for Unit 2 Technical Specifications Tables 3.3-1 , 3.3-3 and LAM Tables 3.10-1 , 3.10-2 I 9 2MSP-36.02D-E, 2AE 4kV Emergency Bus Revision 13 D [81 Loss or Voltage Relays 27-VE200 and 27-VE1200 Test 10 2MSP-36.02-E, 2AE 4kV Emergency Bus Loss Revision 17 D [81 Of Voltage Relay 27-VE1200 Calibration 11 Revision 17 [gj 2MSl-'-36.05-E, 2DF 4kV Emergency Bus Loss Of Voltage Relay 27-VF200 Calibration 12 2MSP-36 .01*E, 2AE 4kV Emergency Bus Loss Revision 17 D [gj Of Voltage Relay 27-VE200 Calibration 13 Revision 17 [gj 2MSP-36.05D*E, 2DF 4kV f-mergency Bus Loss Of Voltage Relays 27 -VF2D0 and 27-VF12C0 Test 14 2MSP-36.15-E, 2AE 4kV 1::mergency Bus Revision 14 D D [81 Diesel Star! Undervoltage Relay 27-VE2200 Calibration

Page vi FlrstEne!f!Y CALCULATION NOP-CC-3002-01 Rev . 05 CALCULATION NO. [) VENDOR CALC

SUMMARY

10080-DEC-0215 Rev. 2 VENDOR CALCULATION NO. NIA 15 2MSP-36.16A-E, 2DF 4kV Emergency Bus Revision 11 D D ~

Diesel Start Undervoltage Relay 27-VF2200 Functional Test 16 2MSP-36.16-E, 2DF 4kV Emergency Bus Revision 12 D D ~

Diesel Start Undervoltage Relay 27-VF2200 Calibration 17 2MSP-36.06-E, 2DF 4kV Emergency Bus Loss Revision 16 D D ~

Of Voltage Relay 27-VF1200 Calibration 18 2MSP-36.15A*E, 2DF 4kV Emergency Bus Revision 12 D D ~

Diesel Start Undervoltage Relay 27-VE2200 Functional Test

Page 1 of 8 F1rstEn~ CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

10080-DEC-0215 2 METHOD OF ANALYSIS The basic uncertainty determination methodology used in this calculation note is the Square Root Sum of the Squares (SRSS}. As documented in Revision O of this calculation note (Westinghouse calculation CN-SSO-99-51 Rev. 0), the Westinghouse methodology combines the uncertainty components for a channel in an appropriate combination of those groups which are statistically and functionally independent. Those uncertainties which are not independent are treated by arithmetic summation and then combined via SRSS with the independent terms .

WCAP-11366 (DIN, Item 6} provides a discussion in Section 2.0 regarding the Westinghouse methodology.

ASSUMPTIONS There are no assumptions associated with this calculation .

ACCEPTANCE CRITERIA In the original uncertainly calculation for the BV2 4.1kV Emergency Bus Undervoltage relays function performed by Westing house, there was no Safety Analysis Limit (SAL) assumed by Westinghouse analyses groups and therefore no explicit acceptance criteria was defined . FENOC was responsible for the determination of acceptability of the calculated uncertainties relative to any operational limits.

FENOC has now determined an Analytical Limit and a re vised NTS for the relays identified in this calculation under Functional Location on Page i. Per DIN , Item 7, an Analytical Limit of 78.2% of 4160 volts and a revised NTS of 81% of 4160 volts have been documented. Based on the calculated CSA, the re should be positive margin between the Analytical Limit and the NTS .

FirstEnergy CALCULATION NO. :

NOP-CC-3002-01 Rev. 05 CALCULATION COMPUTATION Page 2 of 8 REVISION:

10080-DEC-0215 2 COMPUTATION 4.1 kV Emergency Bus Undervoltage - Trip Feed and Start Diesel Undcrvoltage Relays: > Gould Type 47D Model 211 N417l (Section 6.2*)

> Relay Models 21 IN4171. 211N6l7 1 (Reference DIN. Item 3; see Calculation Computation, page 17, 'Results')

(27-VE:O0, 27-VF200, 27-VEIW0, 27-YF1200, 27-VE2200, 27-VF2200)

Item/Term and Value Descri12.tion Reference Sec. vo lts l 20 volts Secondary-side volts, based on relay upper limit/rating Attachment List, Item 3 (08700-01.050-0152 Rev .

D)*

PT Turns 35 Turns ratio of potential transformer, 35 : I Reference 3*

BUS volts 4200 Vac Bus Bus voltage, 120 volts x PT Turns ratio (nominal 4160 volts)

Page 3 of B FirstEnergy CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

10080-DEC-0215 2 Note: The original Westinghouse uncertainty calculation (Rev. 0) based the instrument span on the nominal 4160 volt bus voltage being the upper span limit. In reality, the 120 volt secondary PT voltage relates at a 35 : l ratio to a bus voltage of 4200 volts. In support of initiatives to better define operating parameters for the undervoltage relays and to eliminate any confusion with regards to spans, upper limits, data recording or evaluations, the CSA below is calculated based on 120 volt secondary and 4200 Vac Bus vo ltages . Per the calculation inputs in DIN Item 7 for the Analytical Limit and NTS, the TA, Margin and AV calcul ations are based on the nominal Vac Bus voltage of 4160 volts .

NTS 8 1% Nominal Trip Setpoint % (% of 4160 volts), 3370 Vac Bus Reference DIN, Item 7 (96.3 volts secondary-side, see Page 7 of 8)

SAL N/A Safety Analysis Limit - No value was assumed by Westinghouse in Rev. 0 References 4*. 5*, 14*.

calculation . (see ALmin below for current Analytical limit determined by FENOC) 15*, 16*, 17*

ALrn in 78.2 % Analytical Limit MIN% (% of 4160 volts) Reference DIN, Item 7

Page 4 of B FustEnergy CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. : REVISION:

10080-DEC-021 5 2 Instrument Uncertainties:

Term  % Sec. volts PEAJ 0.30% 0.36 Primary Element Accuracy Reference IO*

Potential transformer accuracy: turns ratio (0.3%)

PEA2 0.25% 0.30 Primary Element Accuracy Reference IO*

Variation in dropout voltage vs . DC control (0.25% per 10% change)

RRA 0.50 Relay Repeatability (0.5 volts, secondary-side) Reference IO*

RCA 0.50 Relay Calibration Accuracy (0 .5 volts, secondary-side) Reference IO*

RMTE 0.23% 0.28 Relay M&TE Accuracy, Fluke 8600A References 3 *, 10*, I I*

Per Fluke 8600A specification (Reference 11 *):

AC Voltage, 2, 20 and 200 volt ranges 0.2% of input+ 0.015% of range 0.2%

• 120 volts+ 0.015%

• 200 volt range= 0.27 volts 0.27 / 120 volts= 0.23%

RTE 2.00% 2.40 Relay Tempernlure Effect (2% variation over -20 to +55°C) Reference I 0*

RD 1.00% 1.20 Relay Drift ( 1.0%) Reference DIN, Item 3

Page 5 of 8 F1rslEne[W CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO .. REVISION:

10080-DEC-0215 2

• Reference/Information identified in I 0080-DEC-02 l 5 Rev. 0 (J'j_ calculation CN-SSO-99-51 Rev. 0)

(Reference DIN, Item I)

Reference DIN, Item 3: 10080-DEC-0222 Rev. 1. "Beaver Valley Units I and 2 Drift Evaluation Results for RTS/ESFAS Relay Instrumentation" (See Calculation Computation, page 17,

'Results' for Relay Models 211 N4 l 71, 21 I N6 l 71)

Channel Statistical Allowance (CSA) Uncertainty Calculation CSA= [PEA 1~ + PEA2 2 + RRA 2 + (RMTE + RCA)2 + (RMTE + RD)2 + RTE 2] 05

+/- 3.00 volts, secondary-side

+/- 105.0 Vac Bus (volts, secondary-side x PT Turns)

Page 6 of 8 FirstEnergy CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

10080-DEC-0215 2 TotaJ Allowance {TA) Calculation TA = IALmin - NTS \

2.8%

3.33 volts, secondary-side (Vac Bus/ PT Turns) 116.5 Vac Bus (of nominal 4160 volts)

Margin Calculation Margin= TA - CSA 0.33 volts, secondary-side (Vac Bus/ PT Turns) 11.5 Vac Bus (of nominal 4160 volts)

Page 7 of 8 FirstEnergy CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

10080..DEC-0215 2 AUowableYalue (AV) Calculation AV = NTS-RD 80.0%

95 . l volts, secondary-side (Vac Bus/ P'T Turns) 3328.0 VacBus (ofnominal4!60volts)

NTS Secondary-side Voltage Calculation NTS= 3370 Vac Bus Reference DIN, Item 7 Secondary-side voltage= Vac Bus / PT Turns 96.3 volts, secondary-side

Page 8 of 8 FJrstEn~ CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

10080-DEC-0215 2 RESULTS In support of calibration of the BV2 4.1 kV Emergency Bus Undervoltage relays and the Maintenance Measured Database (MMD) process/10080-DEC-0222 Rev. 1 (DIN, Item 3), a revised channel uncertainty of 3.0 volts secondary {105.0 Vac Bus) and an AV of 80 .0% (3328.0 Vac Bus, 95.1 volts, secondary) have been determined based on a revised relay drift uncertainty and a revised NTS (DIN, Item 7). Note that the resulting channel uncertainty is calculated in volts (as opposed to'% span' in previous calculations) in support of plant initiatives to better define operating parameters for the undervoltage relays .'

The AV is based on the revised NTS and the rack uncertainty (in this case the relay drift uncertainty) . This is a reasonable approach based on the typical plant approach to drive the relay calibration tolerance to near zero.

The revised NTS is 81 %, 3370 Vac Bus, 96.3 volts, secondary.

The revised NTS has been evaluated with respect to the relay Analytical Limits defined in FENOC calculations (DIN, Item 7) . The Total Allowance (TA) was calculated to be 3.33 volts secondary, 116.5 Vac Bus while the resulting Margin was 0.33 volts secondary, 11 .5 Vac Bus.

CONCLUSIONS This calculation revision is based on what is described in the 'Scope of Calculation' section. Given the acceptable results shown above, this information will be used to update MSPs , relay scaling calculations and Technical Specifications.

Enclosure J L-22-081 Calculation No. E-529, Revision 1, "Beaver Valley Units 1 and 2, Degraded Voltage Relay (DVR) Time Delay Relay Instrument Uncertainty" (13 pages follow)

Page i FustEve!JlV CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. VENDOR CALCULATION NO.

E~529 N/A BV1 BV2 181 BV1/2 n BV3 n BVSWT n DB I 0 PY Title/

Subject:

Beaver Valley Units 1 and 2, Degraded Voltage Relay (DVR) Time Delay Relay Instrument Uncertainty Category: I 181 Active O Historical D Study I Vendor Cale Summary: Yes 0 No 181 Classification: 181 Tier 1 Calculation t8I Safety-Related/Augmented Quality ID Non-safety-Related Open Assumptions?: D Yes 181 No If Yes, Enter Tracking Number System Number: 36 Functional Location : 62-VE220, 62-VF220, 62-VE3100, 62-VF3100 Commitments: None Initiating Documents: ECP 17-0257 for BV2 applicability and ECP 17-0336 for BV1 applicability (PY) Calculation Type:

(PY) Referenced In USAA Validation Database D Yes D No I (PY) Referenced In Atlas? D Yes D No Computer Proi:iram(s)

Program Name Version/ Revision Category Status Description Word Office 2010 C Active Word Processing Rev1s1on Record Originator Approver Rev. Affected Pages Print, Si n & Date All Description of Change: The purpose of the revision is to remov old R 18-00479 that was docu anted in Rev. o a ev. 0 Add . 1 of this calculation which is to be superseded in Its entirety. The BV1/2 4.1 kV Emergency Bus (Trip Feed, Emergency Diesel Generator Start) time delay Channel Statistical Allowance (CSA) uncertainty for new degraded voltage time-delay relay has been established as a result of Calculation E-529, Revision 1. For the purpose of the calculation, there Is no Impact to any plant operation or procedure. The provisions of 10CFR50.59 do not apply to this calculation and a RAD and Screen are not required.

For future BV1 /2 4.1 kV Emergency Bus degraded voltage modifications where this uncertainty calculation will be an input to future associated setting changes, 10CFRS0.59 applicability will be addressed in ECP 18-0055 via Screen 18-00476 for BV2 and ECP 18-0054 via Screen 18-00478 for BV1 .

In addition, there are changes to the maximum Analytical Limit (AL) for BV1 as captured in Rev. 0 Add. 1 of this calculation and the CSA RME (voltage) and RTE (temperature) uncertainty terms as a result of third party review comments . The change to the RME and RTE values resulted in a minor change to the overall CSA value. The change to the CSA value did not change the Rev. 0 conclusion that the calculated Margins are considered adequate for the span between the NTS and Als.

Describe where the calculation will be evaluated for 10CFR50.59 and/or 10CFR72.4B applicability. 10CFA50.59 is not required (see "Description of Change" above) and 10CFR72.48 is not applicable.

Page ii F=lrstEr1e!JlV CALCULATION NOP-CC-3002*01 Rev. 05 CALCULATION NO. [) VENDOR CALC

SUMMARY

E-529, Revision 1 VENDOR CALCULATION NO. N/A TABLE OF CONTENTS SUBJECT PAGE COVERSHEET: i OBJECTIVE OR PURPOSE iii SCOPE OF CALCULATION iv

SUMMARY

OF RESULTS/CONCLUSIONS iv LIMITATIONS OR RESTRICTION ON CALCULATION APPLICABILITY V IMPACT ON OUTPUT DOCUMENTS V DOCUMENT INDEX (DIN) vi CALCULATION COMPUTATION (BODY OF CALCULATION): 1 METHOD OF ANALYSIS 1 ASSUMPTIONS 2 ACCEPTANCE CRITERIA 2 COMPUTATION 2 RESULTS 7 CONCLUSIONS 7 ATTACHMENTS: N/A SUPPORTING DOCUMENTS (For Records Copy Only)

DESIGN INTERFACE

SUMMARY

9 Pages DESIGN VERIFICATION RECORD 1 Pages CALCULATION REVIEW CHECKLIST 3 Pages TOTAL NUMBER OF PAGES IN CALCULATION (COVERSHEETS +BODY+ ATTACHMENTS) 13 Pages

Page iii F,rstEne.!JlY CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.

[ ] VENDOR CALC

SUMMARY

E-529, Revision 1 VENDOR CALCULATION NO. N/A OBJECTIVE OR PURPOSE:

The existing undervoltage protection schemes at BVPS Units 1 and 2 are in the process of being upgraded in order to ensure compliance with NCR 10CFR50 Appendix A General Design Criteria (GDC) 17 (DIN Item 9). Of specific concern, is a sustained degraded voltage condition on the grid which can cause adverse effects on the operation of Class 1E electrical loads. As a result of various industry events, the NRC has requested that all licensees implement degraded voltage protection to ensure automatic protection of safety buses and loads.

The NRC has requested that all licensees review their existing degraded or undervoltage protection schemes in order to ensure voltage setpoints are adequately supported, coincidence logic is considered, the time delay supports the Final Safety Analysis Report (FSAR), the voltage protection automatically initiates the disconnection of inadequate offsite power sources, the voltage relays satisfy the requirements of IEEE 279-1971 (DIN Item 10) and the Technical Specifications include limiting conditions for operation, surveillance requirements, trip setpoints, and allowable values for second-level voltage protection degraded voltage relays.

The NRC identified during inspections that the voltage protection schemes at various plants were not adequate to protect the safety-related components during sustained degraded voltage conditions . Specifically, the existing voltage setpoints were too low to power the safety-related equipment, but high enough to prevent transferring of safety loads to the standby power source . In addition, the time delays provided for the degraded voltage protection relays were not consistent with the accident analysis assumptions for those plants.

As a result of the above clarification, Beaver Valley Power Station reviewed their current design and licensing bases associated with the undervoltage protection scheme and have identified specific areas for improvement in line with the NRC guidance described above.

Specifically, Beaver Valley is working to develop modifications (ECP 17-0257 and ECP 17-0336) of their Degraded Voltage Relay (DVR) time delay relays in order to ensure automatic disconnection of the offsite power source during a concurrent Engineered Safety Features (ESF) actuation. In addition, Beaver Valley has revised their voltage analyses to ensure that the Loss of Voltage Relays (LVRs) have setpoints that support their analyses for maintaining operation of safety-related components.

Specifically, Beaver Valley Power Station identified that the present time-delay relay, set at a 90 second time delay, exceeds the time delay used in the UFSAR accident analysis for Safety Injection delay. This modification will establish a reduced time delay which will be used when the Safety Injection Signal (SIS) is present. The longer 90 second time delay will remain in use when there is no concurrent Safety Injection Signal. In order to implement and support this change :

Page iv FirstEne.!W CALCULATION NOP-CC-3002*01 Rev. 05 CALCULATION NO. [ ] VENDOR CALC

SUMMARY

E-529, Revision 1 VENDOR CALCULATION NO. NIA

1. A new degraded voltage time-delay relay will be installed in parallel with the existing 90 second time-delay relay. The new relay's output will be passed along only when a Safety Injection Signal is active.

2. Modifications will be made to the SSST voltage setpoint such that the reduced time delay will not inadvertently cause the bus to separate from offsite power when the bus voltage is recovering after a fast-bus transfer. This will involve the installation of an interposing relay in the SSST Load Tap Changer cabinet.

For Item 1 above, new ABB Solid State Timing Relays, Type 62T, Model number 417T2170 will be installed as time-delay relays. For BV2 Trains A and B, these timers will be functionally designated as 62-VE220 and 62-VF220 and installed in parallel with the existing time-delay relays. For BV1 Trains A and B, these timers will be designated as 62-VE3100 and 62-VF3100 and installed in parallel with the existing time-delay relays.

The existing degraded voltage 4160V Emergency Bus Separation function actuates at the voltage setpoint with a time delay of 90 +/- 5 seconds. This time delay exceeds the 17 seconds required by the UFSAR for Safety Injection concurrent with the offsite power condition which is described in the accident analysis. To correct this condition, the new time-delay relay will operate , with a time delay that satisfies the requirement, if the Safety Injection Signal is also present at the time of the degraded voltage condition. When the new time-delay relay operates, the loads will be transferred from the System Station Service Transformers (SSST) or the Unit Station Service Transformers (USST) to the Emergency Diesel Generator.

SCOPE OF CALCULATION:

This calculation provides the BV1 /2 4.1 kV Emergency Bus Undervoltage (Trip Feed, Emergency Diesel Generator Start) relay Channel Statistical Allowance (CSA) uncertainty calculation and Allowable Value (AV) calculation for the new ABB Solid State Timing Relays, Type 62T.

SUMMARY

OF RESULTS/CONCLUSIONS:

In support of calibration of the BV1/2 4.1 kV Emergency Bus DVR time delay relays and the Maintenance Measured Database (MMD) process, a CSA uncertainty of +0.33 sec to -0.21 sec and an AV of 4.18 sec to 3.82 sec have been calculated. The Allowable Value (AV) term is based on Relay Drift (RDro) uncertainty (0.18 sec) and the Nominal Trip Setpoint (NTS) (4 .0 sec) .

The NTS (4 .0 sec) has been evaluated with respect to the relay Analytical Limits (Als) defined in FENOC calculations (ALMIN = 2.2 sec and ALMAX =4.7 sec for BV2 and NTS = 4 .0 sec, ALM1N

= 2.5 sec and ALMAx = 4.4 sec for BV1). The Total Allowance (TA) and Margin was calculated and is summarized below.

Page v ArstEne.!JlY CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.

[ ] VENDOR CALC

SUMMARY

E-529, Revision 1 VENDOR CALCULATION NO. NIA ForBV2 TAMAX= 0.70 sec, MARGINMAX= 0.37 sec TAM1N = 1.80 sec, MARGINM1N = 1.59 sec ForBV1 TAMAX= 0.40 sec, MARGINMAx= 0.07 sec TAM1N = 1.50 sec, MARGINM1N = 1.29 sec The calculated Margins are considered adequate for the span between the NTS and Als.

LIMITATIONS OR RESTRICTIONS ON CALCULATION APPLICABILITY:

The results of this calculation are applicable to the specific BV1 /2 4 .1 kV Emergency Bus DVR time delay relays identified under Functional Locations on the calculation coversheet, Page i.

Should the "As-Found" 4.1 kV Emergency Bus DVR relay drift exceed the Maintenance Measured Database (MMD) values during any calibration frequency, a Condition Report (CR) is to be initiated, as is the practice in MMD excessive drift.

IMPACT ON OUTPUT DOCUMENTS:

Revisions to MSPs for test and calibration of the new time delay relays will be addressed in ECP 18-0055 for BV2 applicability and ECP 18-0054 for BV1 applicability.

Page vi ArstEne..!W CALCULATION NOP-CC-3002-01 Rev. 05 CALCULATION NO. [] VENDOR CALC

SUMMARY

E-529, Revision 1 VENDOR CALCULATION NO . NIA DOCUMENT INDEX Q) 0 0

5 z C:

~

5 C.

z Document Number/Title Revision, Edition, Date Q)

E C.

'S 0 'ai 0 a:

1 ABB IB 7.7 .1.7-6, Instructions Solid-State Issue D D l8'J D Timing Relay, Circuit Shield Type 62T f - - - - -- ------- -- ---- -- --

2 ES-E-009, Beaver Valley Power Station Revision 0 D l8'J Engineering Standards Manual, Instrumentation Setpoint Calculations _,

3 2220.100-001-176, 'WCAP-11366-P Rev. 7, Revision A D l8'J Westinghouse Setpoint Methodology for Protection Systems

• Beaver Valley Power Station Unit 2" 4 8700-05.010-0018, 'WCAP-11419-P Rev. 6, Revision A D l8'J Westinghouse Setpoint Methodology for Protection Systems - Beaver Valley Power Station Unit 1" 5 Beaver Valley Power Station Unit 1 and 2 278/161 D 18]

Technical Specifications Bases; Section B 3.8.4 "DC Sources - Operating*

6 DIT-BVDM-0101-00, "Transmittal of Analytical February 13, 2018 D 18]

Limits and Nominal Trip Setpoints for BV1 and BV2 Loss of Voltage Relays (LVRs) and New Degraded Voltage Relay (DVR) Timers 7 ES-M-013, "Environmental Conditions for 7 D 18]

Equipment Qualification Requirements" BV2 8 ES-M-012, "Environmental Conditions for 4 D l8'J D Equipment Qualification Requirements" BV1 9 USN RC 10CFR50 Appendix A General Design 181 D Criteria 17, Electric Power Systems 10 IEEE Standard 279, "Criteria for Protection 1971 181 D Systems for Nuclear Power Generating Stations"

---*--*- ~- - *--- . --* ---**- - --- *- - -*-* -* *- . - -* .. *-* - ----

11 ANSI /ISA Standard S51 , 1, "Process 1979 (reaffirmed 1993) 181 Instrumentation Terminology" 12 8700-E-345, "Voltage and Time Delay Analys is Revision 1 18]

fo r Unit 1 Undervoltage Protection Scheme" 13 100080-E-346, "Voltage and Time Delay Revision 1 l8'J D Analysis for Unit 2 Undervoltage Protection Scheme" 14 8700 -E-271 , "BVPS Unit -1 Stotion Service Revision 3, Addendum 4 ~ D System Dynamic Stability Analysis"

• • -*---- 1--- * - -------- ----*--- ------------ - **------ *-- *-* -*------------* ---- - . -- - . ----

15 10080-E-271 , "BVPS Unit-2 Transient Stability Revision 1, Addendum 6 ~

t_--- Analysis"

Page 1 of 7 F,~ CALCU LATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

E-529 1 METHOD OF ANALYSIS:

Per DIN Items 2, 3 and 4 the uncertainty guidelines for time delay relays are not specifically addressed. Also, the time delay relays are new with no existing plant calibration data or vendor supplied drift values.

Generically, the Channel Statistical Allowance (CSA)/Channel Uncertainty (CU) for a rack or components is modelled as:

CSA = +/- (A 2 + B2 + C2 ) 0 *5 + L - M Where A, B, C etc. are random uncertainty terms and L is bias uncertainty in a positive direction and M is bias uncertainty in a negative direction, The above equation employs the square root of the sum-of-squares industry standard methodology. Taking the square root of the sum-of-squares is an effective way to combine uncertainties into one value, and squaring each contributing term before taking the sum has some important advantages :

1. Positive and negative contributors to the uncertainty do not accidentally "cancel out".

2. Larger error sources are magnified compared to smaller ones, and this is desirable for identifying severe problems .

3. Sum-of-squares does not over-estimate uncertainty as an extreme worst-case scenario.

For the purpose of this calculation, the below equation will be used for time delay uncertainty.

Best engineering judgment was used per DIN Items 3 and 4 guidelines in selecting applicable uncertainty terms as follows:

2 2 CSA = +/-( (RCA + RMTE) + (RD + RMTE)2 + RTE + RME 2 05

) * + RFD + PMA

• CSA = Channel Statistical Allowance uncertainty - The total uncertainty of an instrument channel or component. This is the minimum allowable difference between the design value and the Nominal Trip Setpoint (NTS) value.

• RCA == Rack or Component Calibration Accuracy.

• RMTE = Rack or Component Measuring and Test Equipment Uncertainty.

• RD = Rack or Component Drift or Stability.

• RTE= Rack or Component Ambient Temperature Effects .

• RME = Rack or Component Miscellaneous Effects

• RFD== Rack or Component Relay Fixed Delay Effects (Positive Bias)

• PMA = Rack or Component Process Measurement Allowance Effects (Positive Bias)

Page 2 of 7 FlrstEne~ CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

E-529 1 ASSSUMPTIONS:

None ACCEPTANCE CRITERIA:

Per DIN Item 6, as modified by DIN Item 12, the new time delay relays have setpoints and analytical limits as follows; Nominal Trip Setpoint (NTS) = 4.0 sec, Analytical Limit MIN (ALM1N)

= 2.2 sec and Analytical Limit MAX (ALMAx) =4 .7 sec for BV2 and NTS = 4.0 sec, ALM1N = 2.5 sec and ALMAx = 4.4 sec for BV1. Based on the calculated CSA, there should be positive margin between the Analytical Limit and the NTS.

COMPUTATION:

Channel Statistical Allowance (CSA) Calculation The new time delay relays have setpoints and analytical limits as follows; NTS = 4 .0 sec, ALM1N

= 2.2 sec and ALMAX =4.7 sec for BV2 and NTS = 4.0 sec, ALM1N = 2.5 sec and ALMAX = 4.4 sec for BV1 . As such selected ABB 62T timer will be specified with a factory preset range of 0.01-9.99 sec. This range will be used for determining the values for the RCAm, RMTEm, RDrn, RTETD, RMEm and RFDrn terms .

Per DIN Item 1, ABB 62T timer reference accuracy at the full range of 9.99 seconds is +/-0.5%

or +/-15ms or+/- 1 digit of setting (whichever is greater) . The 1 digit on a relay with a range of 0.01-9.99 sec is equal to 1O ms.

For BV2 For the NTS = 4.0 sec, +/-0.5% x 4 .0 sec= +/-0.02 sec.

For the NTS = 4. 0 sec, the calculated value is greater than 10 and 15 ms. Therefo re , the calculated value is used.

RCAm NOM = +/-0.02 sec For BV1

Page 3 of 7 ArstEnerJ!Y CALCULATION COMPUTATION NOP*CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

E-529 1 For the NTS = 4.0 sec, +/-0.5% x 4.0 sec= +/-0.02 sec.

For the NTS = 4.0 sec, the calculated value is greater than 1O and 15 ms. Therefore, the calculated value is used.

RCAm NOM = +/-0.02 sec RMTEm Per DIN Items 3 and 4, ANSI/ISA Standard S51 .1 (DIN Item 11) indicates that if the Measurement and Test Equipment (MTE) uncertainty is 10 times more accurate than the device being tested, the associated MTE uncertainty is considered negligible.

Per DIN Item 1, if an acceptance test indicated a need for recalibration, a trimmer resistor is adjusted to obtain a frequency range of 999.5 to 1000.5 Hz for a relay timing range of 9.99 sec as indicated using a frequency counter. This recalibration yields a 1 Hz accuracy for timer calibration. It can be assumed, based on best engineering judgement, that the frequency counter will have an accuracy 1O times more accurate than the above ABB 62T timer calibration accuracy.

RMTErn = 0 sec RDrn BVPS does not currently have calibration data for the ABB 62T. In addition ABB does not publish drift values for the ABB 62T series of relays.

Per DIN Item 1, ABB 62T relays are solid state digital timers. The time delay is available with a 0.001-0.999 second range, 0.01-9.99 sec range, 00.1-99.9 sec range and a 001-999 sec range.

As previously identified, the relays will use the 0.01-9.99 sec range compatible with DIN Items 6 and 12 setpoint and analytical limit values. However since the setpoint is set using thumbwheels in a digital circuit, the drift only applies to the oscillator circuit for the duration of the timing . Hence the span considered for drift will only be for the duration to reach the setpoint.

Page 4 of 7 Ftf'StEne.!llv CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CAL CU LATION NO.: REVISION:

E-529 1 In the absence of vendor supplied drift values and plant calibration data for the new time delay relays, a 30 month calibration interval drift value of 1%, adjusted to a 54 month calibration interval, yielding a 1.8% drift value, will be conservatively applied based on best engineering practice. This 1.8% drift value is comparable to BVPS guidance in DIN Item 2, when supplied or historical drift values are not readily available. The full range 9.99 sec of the time delay relay will be used as the span.

For the full span of 9.99 seconds, +/-1.8% x 9.99 sec= +/-0.18 sec.

RDrn = +/-0.18 sec RTEm Per DIN Item 1, ABB 62T relays have a temperature effect of +/-2%, +/-20ms or +/-1 digit (whichever is greater) over a temperature range of -4°F (-20°C) to 158°F (70°C) (range of 162°F). The 1 digit on a relay with a range of 0.01-9.99 sec is equal to 1O ms.

The new time-delay relays will be installed near the existing time-delay relays. They will be located at Unit 2 and 1 Service Buildings. The environmental conditions of the Unit 2 and 1 Service Buildings are listed as mild in DIN Items 7 and 8.

For BV2, the Normal Service Conditions are 55 to 104°F. Anticipated Service Conditions under Loss of Offsite Power and Accident Conditions is 104°F.

For BV1, the Normal Service Condition is 120°F maximum. Anticipated Service Conditions under Loss of Offsite Power and Accident Conditions is 120°F.

The actual temperature ranges are within DIN Item 1, specified temperature range. The temperature effect is determined by using the NTS value of 4.0 sec.

RTEro = 2% x 4.0 sec= +/-0.08 sec RMErn Per DIN Item 1, ABB 62T relays have a control voltage variation effect of +/-2%, +/-15ms or +/-1 digit (whichever is greater) over a control voltage variation of -20%, + 10%. The 1 digit on a relay with a range of 0.01-9.99 sec is equal to 10 ms. The actual control voltage is within DIN Item 1 tolerances based on battery sizing per DIN Item 5.

Page 5 of 7 FlrstEo@!flV CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION :

E-529 1 The voltage variation effect is determined as follows :

The actual voltage range is within the DIN Item 1 voltage range . The voltage effect is determined by using the NTS value of 4.0 sec.

RMErn = 2% x 4.0 sec= +/-0.08 sec Positive Bias Terms RFDrn and PMArn

-8.EQm Per DIN Item 1, the ABB 62T timer has fixed delays. For the timer stage, the value is 0.5 times the least significant digit. For the range of 0.01 -9 .99 sec, the least significant digit is 0 .01 sec.

For the full range of 9.99 sec, the timer fixed delay is 0.5 x 0.01 sec= +0.005 sec.

For the output stage, the fixed delay is 5-16 ms with a 7 ms nominal value . Conservatively, the 16 ms value will be used.

RF Orn= 0.005 + 0.016 = +0.02 sec PMAro Per DIN Item 6, ALMAX times do not account for the 0.1 sec time delay of the DVR voltage relays. Calculated MAX times must be reduced by 0.1 sec to account for this delay.

PMArn = 0.1 sec CSArn Plugging in the above calculated value for each uncertainty term yields 2

CSArn = +/-((RCAro + RMTErn) + (RDrn + RMTEm)2 + RTErn + RMErn 2 2

)°- 5 + RFDro + PMArn Note positive bias terms RFDrn and PMArn will only be applied to ALMAX side of the NTS .

2 2 05 CSArn = +/-( (0.02 + 0)2 + (0.18 + 0)2 + 0.08 + 0 .08 ) + 0.02 + 0.1

Page 6 of 7 F~ CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

E-529 1 CSAro = +0.33 sec to -0.21 sec for both BV2 and BV1 Total Allowance (TA) Calculation ForBV2 TAMAx= absolute [ALMAx- NTS] =absolute [4.70-4.00] =0.70 sec TAM1N = absolute [ALM1N - NTS] = absolute [2.20 - 4.00] = 1.80 sec For BV1 TAMAX = absolute [ALMAX - NTS] = absolute (4.40- 4.00] = 0.40 sec TAM1N = absolute [ALM1N- NTS] = absolute [2.50 - 4.00] = 1.50 sec Margin Calculation For BV2 MARGINMAX = TAMAX - absolute [CSArn+J =0.70 - 0.33 = 0.37 sec MARGINM1N = TAM1N - absolute [CSArn.) = 1.80- 0.21= 1.59 sec For BV1 MARGINMAX =TAMAX - absolute [CSArn+l =0.40 - 0.33= 0.07 sec MARGINM1N =TAM1N- absolute [CSArn.) = 1.50 - 0.21 = 1.29 sec Allowable Value (AV) Calculation Allowable values are calculated based on the RCArn or RDrn term only per guidance in DIN Items 3 and 4. Since the RCArn term is quite small (0.02 sec) , the more conservative RDrn value was used (0.18 sec) .

AV= NTS +/- RDrn = 4.00 +/- 0.18 = 4.18 sec to 3.82 sec

Page 7 of 7 First~ CALCULATION COMPUTATION NOP-CC-3002-01 Rev. 05 CALCULATION NO.: REVISION:

E-529 1 RESULTS:

In support of calibration of the BV1/2 4.1kV Emergency Bus DVR time delay relays and the Maintenance Measured Database (MMD) process, a CSA uncertainty of +0.33 sec to -0.21 sec and an AV of 4.18 sec to 3.82 sec have been calculated. The Allowable Value (AV) term is based on Relay Drift (RDro) uncertainty (0.18 sec) and the NTS (4.0 sec).

The NTS (4.0 sec) has been evaluated with respect to the relay Analytical Limits (Als) defined in FE NOC calculations (ALM1N = 2.2 sec and ALMAx =4.7 sec for BV2 and NTS = 4.0 sec, ALM1N

= 2.5 sec and ALMAx = 4.4 sec for BV1 ). The Total Allowance (TA) and Margin was calculated and is summarized below.

ForBV2 TAMAx= 0.70 sec, MARGINMAx= 0.37 sec TAM1N = 1.80 sec, MARGINM1N = 1.59 sec For BV1 TAMAx= 0.40 sec, MARGINMAx= 0.07 sec T AM1N = 1.50 sec, MARGI NM1N = 1.29 sec CONCLUSIONS:

In support of calibration of the BV1/2 4.1kV Emergency Bus DVR time delay relays and the MMD process , a CSA uncertainty of +0.33 sec to -0 .21 sec and an AV of 4.18 sec to 3.82 sec have been calculated.

The NTS has been evaluated with respect to the relay Als defined in FENOC calculations .

The calculated Margins are considered adequate for the span between the NTS and Als .