NL-16-0007, Technical Specification 3.3.5, Loss of Power Diesel Generator Start Instrumentation, Supplement to License Amendment Request
| ML16012A457 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 01/12/2016 |
| From: | Pierce C Southern Nuclear Operating Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NL-16-0007 SE-SNC529029-001, SE-SNC529029-002, SJ-SNC529029-001 | |
| Download: ML16012A457 (53) | |
Text
Charles A. Pierce Southern Nuclear Regulatory Affairs Director Operating Company, Inc.
40 Inverness Center Parkway Post Office Box 1295 Birmingham, AL 35242 Tel 205 .992.7872 SOUTHERN << \
Fax 205.992.7601 NUCLEAR A SOUTHERN COMPANY January 12, 2016 Docket Nos.: 50-348 NL-16-0007 50-364 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Joseph M. Farley Nuclear Plant, Units 1 and 2 Technical Specification 3.3.5 Loss of Power Diesel Generator Start Instrumentation Supplement to License Amendment Request Ladies and Gentlemen:
In accordance with the requirements of 10 CFR 50.90, Southern Nuclear Operating Company (SNC) submitted a request via a letter dated November 20, 2015 (NL-15-0722}, for an amendment to the Joseph M. Farley Nuclear Plant (FNP) Units 1 and 2 Technical Specifications (TS}. That amendment request proposes to revise TS 3.3.5, "Loss of Power Diesel Generator Start Instrumentation," to enable compliance with a license condition for each unit which requires elimination of manual actions as part of the FNP degraded voltage protection scheme.
Included in the proposed changes toTS 3.3.5 are new voltage and delay time Allowable Values for the 4.16 kV Emergency Bus Degraded Grid Voltage Actuation function. As a supplement to the November 20, 20151icense amendment request, enclosed are copies of the calculations which support these new Allowable Values.
Enclosures 1 and 2 are the calculations which established the delay times for the degraded grid voltage relays for Units 1 and 2, respectively; Enclosure 3 is the calculation which established the relay actuation voltages for both units.
Provided are the bodies of the calculations, which detail the methodology employed and the results obtained. The attachments to the calculations have been omitted since their inclusion would add several hundred pages of material only peripheral to the requested changes (such as modeling software output reports, relay manufacturer's specifications, etc.).
In accordance with the requirements of § 50.91, a copy of this supplement to SNC's November 20, 2015 license amendment request is provided to the designated Alabama official.
U.S. Nuclear Regulatory Commiss ion NL-16-00 07 Page 2 This letter contains no NRC commitments. If you have any questions, please contact Ken McElroy at (205) 992-7369.
Mr. Pierce states he is Regulato ry Affairs Director of Southern Nuclear Operating Company, is authorized to execute this oath on behalf of Southern Nuclear Operating Company and to the best of his knowledge and belief, the facts set forth in this letter are true.
Res2~7J;;d, C. R. Pierce Regulatory Affairs Director
, 2016.
My commission expires: /6- !'-J.ot1 CRP/DW D/cg
Enclosures:
- 1. FNP Unit 1 Calculation SE-SNC529029-001 - Minimum Expected Voltage Study
- 3. FNP Units 1 & 2 Calculation SJ-SNC529029-001 -Determi nation of Setpoints cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, Presiden t & CEO Mr. D. G. Bast, Executive Vice Presiden t & Chief Nuclear Officer Ms. C. A. Gayheart, Vice Presiden t- Farley Mr. D. R. Madison, Vice Presiden t- Fleet Operation s Mr. M. D. Meier, Vice Presiden t- Regulato ry Affairs Mr. B. J. Adams, Vice Presiden t- Engineering Ms. B. L. Taylor, Regulatory Affairs Manage r- Farley RType: CFA04.0 54 U.S. Nuclear Regulatory Commiss ion Mr. L. D. Wert, Regional Administr ator Mr. S. A. Williams, NRR Project Manager - Farley Mr. P. K. Niebaum, Senior Resident Inspecto r- Farley Alabama Departme nt of Public Health Dr. D. E. Williamson, State Health Officer
Joseph M. Farley Nuclear Plant, Units 1 and 2 Technical Specification 3.3.5 Loss of Power Diesel Generator Start Instrumentation Supplement to License Amendment Request Enclosure 1 FNP Unit 1 Calculation SE-SNC529029-001 Minimum Expected Voltage Study (Attachments to calculation not included)
SOUTHERN COMPANY A. Southern Nuclear Design Calculation E*nu"' Snw Yoar W&riJ" Calculation Number:
SE-SNC529029-001 Plant: 1 Unit: I Discipline:
J.M. Farley Nuclear Plant
Title:
Unit 1 Minimum Expected Voltage Study
~1 02 01&2 I
Subject:
Electrical AC System Analysis Purpose I Objective:
Determine safe operating limits of Unit 1 under degraded grid conditions System or Equipment Tag Numbers:
R01,R11,R15,R16,R17 Contents Topic Page Attachments #of (Computer Printouts, Technical Papers, Pages Sketches, Correspondence)
Version History 1 1. Summary of Steady-State and Starting 9
Design Inputs 1 Voltages at Minimum Required Voltage References 1 2. ETAP Output Reports - NORMAL Load Flow 93 Purpose of Calculation 2 3. ETAP Output Re_Qorts- LOCA Load Flow 102 Summary of Conclusions 2 4. ETAP Output Reports- Motor Starting 44 Methodology 4 5. Safety Injection Transient Plots 1 Assumptions 5 6. Thermal Overload Trip Time Tables 2 Acceptance Criteria 6 7. AC Voltage DroQ_ from PT to DVR 1 Body of Calculation 6 Total# of Pages including 264 cover sheet & Attachments:
CJ Version Record Versio Originator Reviewer Approval1 Approval2 n Description Printed Name Printed Name Printed Name Printed Name No. Initial/ Date lnltlal/Dal8 Initial/ Date Initial/Date Kaleb Drew Matt Lane i-f"~"' Mite 1..7 1.0 Issued per RER SNC529029, v1.0
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Notes: An OE search has been performed and the results are documented in the Methodology Section.
NMP-ES-039- F01 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 1 of 11 Version History:
Version 1.0: Initial version issued for RER SNC529029.
Design Inputs:
- 1. SE-94-0470-001, Ver. 7.0, Unit 1 As-Built Load Study: Primary calculation input; source of ETAP model and methodology used for case study runs.
- 2. SE-94-0470-004, Ver. 4.0, Unit 1 Load Study Summary: LOCA starting and steady-state requirements tables modified for use as Attachment 1 of this calculation.
- 3. SJ-SNC529029-001, Ver. 1.0, Determination Of Setpoints, Reset Points, And Loop Uncertainties For 4160V Safety-Related Degraded Voltage Relay (DVR) Loops (Buses 1F, 2F, 1G And 2G)
References:
- 1. GDC 17, General Design Criteria for Nuclear Power Plants 17
- 2. IEEE Standard 399-1997, IEEE Recommended Practice for Industrial and Commercial Power Systems Analysis
- 3. NRC Regulatory Issue Summary 2011-12, Revision 1, Adequacy of Station Electric Distribution System Voltages: Guidance for degraded grid analysis acceptance criteria and methodology
- 4. Farley Nuclear Plant Units 1 & 2 Tech Spec Bases, Rev. 65
- 5. Farley Nuclear Plant Unit 1 Tech Spec, Amendment 195
- 6. Farley Nuclear Plant Units 1 & 2 FSAR, Rev. 26, Feb. 2015
- 7. SM-90-1653-002, Ver. 23.0, Reduced Voltage Torque/Thrust Capability for Gate &
Globe Valves in the FNP MOV Program
- 8. SM-90-1653-009, Ver. 8.0, Reduced Voltage Torque Capability for Butterfly Valves in the FNP MOV Program
- 9. SM-1053039201-001, Ver. 1.0, Develop Design Basis Calculations for the Penetration Room Filter Dampers
- 10. DOEJ-FRSNC52029-M001, Ver. 1.0, Evaluation of Reduced Voltage Requirements for Motor Operated Valves for use in the Degraded Voltage Protection Plan
- 11. E-035.01.A, Ver. 6.0, Setting of Protective Relays for 4.16kV Auxiliary Power System
- 12. SE-90-1845-2-PE, Ver. 8.0, Large, Small, and SBO Diesel Dynamic Study
- 13. SE-91-1976-1, Ver. 6.0, Motor Starter Control Circuit Study
- 14. SE-91-1925-14-PE, Ver. 1.0, MOV3232A,B,C: Terminal Voltage at End of Stroke
- 15. SE-99-9472-001, Ver. 1.0, Stability Review for LOSP/DGG Relay Operation
- 16. SE-94-0-0378-001, Ver. 5.0, MOV Combination Starter Component Sizes and Settings
- 17. SE-99-0-2010-001, Ver. 0.0, Verification Package for Computer Software Used to Calculate MOV Thermal Overload Heater Sizes
- 18. SE-90-1714-12, Ver. 4.0, Overload Heater Sizing and Resistance
- 20. 1995 SER, February 23, 1995, Safety Evaluation for Degraded Grid Voltage Relay Set Points
- 21. IB 7.4.1.7-7, Issue E, ABB Instructions Single Phase Voltage Relays
- 22. GEH-1768G, GE Instructions: Undervoltage Relays
- 23. MC-F-06-0143, Ver. 1.0 NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 2 of 11
- 24. MC-F-07-0014, Ver. 1.0
- 25. MC-F-07-0050, Ver. 2.0
- 26. MC-F-07-0110, Ver. 1.0
- 27. MC-F-07-0116, Ver. 1.0
- 28. MC-F-08-0017, Ver. 3.0
- 29. MC-F-08-0026, Ver. 1.0
- 30. MC-F-08-0076, Ver. 1.0
- 31. MC-F-08-0083, Ver. 1.0
- 32. MC-F-08-0091, Ver. 1.0
- 33. MC-F-08-0162, Ver. 1.0
- 34. MC-F-08-0194, Ver. 1.0
- 35. MC-F-10-0003, Ver. 1.0
- 36. MC-F-10-0005, Ver. 1.0
- 37. MC-F-10-0037, Ver. 1.0
- 38. MC-F-10-0094, Ver. 1.0
- 39. MC-F-10-0127, Ver. 1.0
- 40. MC-F-11-0022, Ver. 1.0
- 41. MC-F-11-0077, Ver. 1.0
- 42. MC-F-11-0090, Ver. 1.0
- 43. MC-F-12-0002, Ver. 1.0
- 44. MC-F-12-0031, Ver. 1.0
- 45. MC-F-12-0071, Ver. 3.0
- 46. MC-F-12-0086, Ver. 2.0
- 47. MC-F-13-0087, Ver. 1.0
- 48. MC-F-14-0009, Ver. 1.0
- 49. MC-F-14-0029, Ver. 1.0
- 50. MC-F-15-0051, Ver. 1.0
- 51. CCN-F-11-0003, Ver. 3.0 Purpose of Calculation:
The purpose of this calculation is to determine the operating range of Farley Nuclear Plant Unit 1 under degraded voltage conditions at the 230kV grid to meet the requirements of the safety-related loads using the guidance in Regulatory Issue Summary RIS 2011-12, Revision 1 (Reference 3). This operating range is used by other calculations to determine Degraded Voltage Relay (DVR) settings to automatically transfer safety-related loads from an unacceptable offsite power source to an onsite power source.
Summary of
Conclusions:
- 1. The minimum voltage that meets the steady-state requirements for all safety-related loads during the Normal and LOCA loading cases for Farley Unit 1 is determined, and is documented in Table 1a as the Minimum Required Voltage (MRV). Refer to Attachments 2 and 3 for ETAP output reports.
- 2. The required starting voltage at the safety-related motors and MOVs is satisfied for the motor starting cases established in calculation SE-94-0470-004 (Design Input 2). Refer to Attachment 4 for ETAP output reports.
NMP-ES-039- F02 NMP-ES-039-001
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J.M. Farley Nuclear Plant SE-SNC529029-001 3 of 11
- 3. Some of the safety-related MCCs have voltages below the minimum level required for motor control circuits during the safety injection group motor start; however, per calculation SE-91-1976-1 (Reference 13), these MCCs are acceptable because with the 4kV buses at the MRV, they have the minimum required relay pickup voltage to energize upon an SI signal prior to the motor starting transient. Additionally, load voltages remain above the relay drop-out voltage. See Attachment 1 for motor starting bus voltages.
- 4. The MRV, shown in Table 1a, is lower than the DVR Lower Analytical Limit (LAL). This LAL is selected to provide margin below the DVR setpoint uncertainty range determined in Design Input 3 and above the MRV. Thus the dropout voltage of each DVR will be set such that the minimum tolerance is above the MRV for the 4160V buses 1F and 1G.
- 5. The Minimum Expected Voltage (MEV), shown in Table 1a, is higher than the DVR Upper Analytical Limit (UAL). This UAL is selected to provide margin above the DVR setpoint uncertainty range determined in Design Input 3 and below the MEV. Thus the reset voltage of each DVR will be set such that the maximum tolerance is below the MEV for the 4160V buses 1F and 1G.
- 6. The total available electrical margin available is 1.20% and 1.48% for 4160V buses 1F and 1G, respectively, per the results in Table 1a.
- 7. The DVR time delay should be set, with tolerances, so that the time is not less than the Safety Injection (SI) Transient Time, and not greater than the minimum thermal overload (TOL) relay trip time, as shown in Table 1b. It is the recommendation of this calculation to set the DVR time delay at 9.0 seconds to keep the safety-related loads on the grid as long as possible while also preventing safety-related motors from tripping due to extended overload conditions. Safety Injection Transient plots are included in Attachment 5, and TOL trip times for SI motors when below the MSV are listed in Attachment 6.
- 9. The dropout voltage of each LOSP Relay (78.25% per Reference 11) is below the Minimum Starting Voltage (MSV) shown in Table 1a for the 4160V buses 1F and 1G, which occurs immediately after a LOCA group motor start, so there is no expected interaction between the new DVR and the existing LOSP Relay.
Table 1a. Summary of Unit 1 Degraded Voltage Relay Operating Range Results.
4.16kV Bus 4.16kV Bus DVR Margin 4.16kV 4.16kV MEV DVR UAL MRV DVR LAL (MEV-MRV)
Bus Bus MSV (Attach. 2) (Attach. 1) - (UAL-LAL) 1F 93.31% 92.76% 88.92% 89.57% 81.93% 1.20%
1G 93.26% 92.53% 88.60% 89.35% 81.19% 1.48%
Table 1b. Summary of Unit 1 DVR Timing Analysis.
4.16kV SI Transient Start Time TOL Trip Time DVR Trip DVR Time Delay Bus (Attach. 5) (Attach. 6) Setpoint Allowable Value*
1F 6.5 seconds 11.5 seconds 9.0 seconds 11.4 seconds 1G
- Tech. Spec. DVR Time Setting Requirement NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 4 of 11 Methodology:
The computer model of Farley Unit 1, FNP1V07, was developed with ETAP Version 12.6.0N software package for calculation SE-94-0470-001 (Design Input 1). This calculation uses ETAP software to perform analysis of the auxiliary system including load flow, motor starting, and transient studies. Refer to the ETAP User Guide 12.6 for additional information regarding the ETAP program.
Before the ETAP model was used for this study, outstanding modification calculations (MCs) against base calculation (BC) SE-94-0470-001 (Design Input 1) were merged into the base revision in order of MC approval dates. See Table 2 in the calculation body for a detailed list of merged MCs. The ETAP model was then used to determine several values at the 4kV buses 1F and 1G: the Minimum Expected Voltage, the Minimum Required Voltage, the Minimum Starting Voltage, and the Safety Injection (SI) Transient Time. The methodology for each is described below.
- 1. Minimum Expected Voltage (MEV): The MEV is calculated as the 4kV bus voltage during LOCA steady-state with a 230kV switchyard voltage of 101.0%. In the Farley Unit 1 ETAP model FNP1V07, this is the Load Flow Study Case 1.4.
- 2. Minimum Required Voltage (MRV): The MRV is the maximum requirement of the following three calculations.
- a. Using maximum expected non-accident bus loading, determine minimum acceptable steady-state voltage for normal operation of Class 1E loads. This was performed using ETAP load flow study cases 1.3F and 1.3G.
- b. Using maximum expected accident loading, determine the minimum pre-start voltage that provides acceptable Class 1E motor starting (e.g. during LOCA group motor starting). This was performed using ETAP load flow study cases 1.4F and 1.4G.
- c. Using maximum expected accident loading, determine the minimum steady-state voltage that provides acceptable Class 1E motor operation and starting for individual motors. This was performed using ETAP motor starting study cases 4F MOV Start, 4G MOV Start, 5F LOCA Start, 5G LOCA Start, 7F LOCA ST A, and 7G LOCA ST A.
- 3. Minimum Starting Voltage (MSV): The MSV is calculated as the lowest voltage at the 4kV bus during a safety injection transient (ETAP motor starting study cases 5F LOCA Start and 5G LOCA Start) with the pre-start voltage at the MRV.
- 4. Safety Injection Transient Time: The SI Transient Time is calculated as the minimum time for the SI group motors to start and reach steady-state with the 4kV buses at the MRV. The ETAP Transient Study Case used to analyze the SI group start is developed as a part of this calculation.
NMP-ES-039- F02 NMP-ES-039-001
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J.M. Farley Nuclear Plant SE-SNC529029-001 5 of 11 MEV MRV SI Transient Time MSV Figure 1. Example SI transient showing location of MEV, MRV, MSV, and SI Transient Time.
The OE search was performed using the following keywords:
- Degraded Grid Relay Date OE Problem Relevance / Action /
Source Impact Resolution 11/19/2009 INPO OE30473: Potential Inaccurate No motors Only applies to Induction Motor Models in ETAP- modeled at older version of Davis-Besse Unit 1: greater than ETAP. No action The cumulative load increases due 100% loading. is required.
to induction machine modeling techniques may result in non-conservative AC Power System Analyses. For motors operating at greater than 100 percent, allowing efficiency at 100 percent motor load to adjust results in a non-conservative estimate (under prediction) of EDG loading due to the ETAP extrapolation of motor efficiency beyond 100 percent loading.
Assumptions:
- 1. A minimum expected grid voltage of 101.0% at the 230kV Reference Bus is assumed and utilized in the ETAP model based on contingency studies defined by the FSAR (Reference 6).
- 2. Loads listed in Attachment 1 with steady-state voltages that do not have motor starting criteria are assumed to be able to endure a transient motor starting situation.
- 3. Low motor starting voltage for the 3232 MOVs on 600V MCC 1V can be considered acceptable during block starting since the MOVs start with no load. Per SCS Calculation SE-91-1925-14-PE (Reference 14), the maximum load occurs at the end of the close of the stroke when the motors are already running.
NMP-ES-039- F02 NMP-ES-039-001
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J.M. Farley Nuclear Plant SE-SNC529029-001 6 of 11
- 4. A constant grid impedance of 0.87+j1.125 percent of 100MVA base is assumed and utilized in the ETAP model per calculation SE-94-0470-001, Attachment C (Design Input 1).
- 5. ABB 27N calibration limits are determined to be +/-0.5 seconds from the Plant Hatch Surveillance Procedure for degraded voltage alarm relays 57SV-S32-002-1, Emergency Buses 1E, 1F, and 1G Undervoltage Relay Instrument FT&C, Attachment 3.
Acceptance Criteria:
- 1. The required steady-state voltages at the motor terminals are established in calculation SE-94-0470-004 (Design Input 2). Non-1E motors/loads are allowed to be below 90%
rated voltage, since they are not required to mitigate a design basis event.
- 2. The required starting voltages at the safety-related motors are established in calculation SE-94-0470-004 (Design Input 2). All safety-related motors must be capable of starting at the corresponding MRV.
- 3. The required MOV starting voltages were established in mechanical torque calculations SM-90-1653-002 (Reference 7), SM-90-1653-009 (Reference 8), and SM-1053039201-001 (Reference 9), as listed in SE-94-0470-004 (Design Input 2). These starting requirements have been updated by DOEJ-FRSNC529029-M001 (Reference 10). All safety-related MOVs must be capable of starting at the corresponding MRV.
- 4. With the 4kV bus pre-start voltage at the MRV, the SI transient time should be less than the minimum TOL trip time to prevent safety-related equipment from stalling or tripping on overcurrent during a degraded voltage condition.
- 5. The MRV must be lower than the LAL, and the MEV must be higher than the UAL. The Analytical Limits must be selected to provide margin above and below the setpoint uncertainty range determined in Design Input 3.
Body of Calculation:
ETAP was used to simulate normal and accident conditions with a concurrent degraded grid condition. Outstanding MCs and CCNs (References 23-50) against SE-94-0470-001 (Design Input 1) were merged into the ETAP base revision of Farley Unit 1 model FNP1V07 in accordance with Table 2 before any case studies were analyzed. The methodology used in Design Input 1 was followed to set up the ETAP study cases. The 230kV source voltage was modified to obtain the desired voltage at the 4kV bus being studied for each case.
Table 2. List of Outstanding MCs Merged into ETAP Model Base Revision.
Approval MC Number Merged Notes Date MC-F-06-0143 v1.0 9/28/2006 Yes MC-F-07-0014 v1.0 2/7/2007 No Non-conservative MC-F-07-0110 v1.0 12/13/2007 Yes MC-F-07-0116 v1.0 12/13/2007 Yes MC-F-08-0076 v1.0 6/6/2008 Yes MC-F-08-0083 v1.0 7/11/2008 Yes MC-F-08-0091 v1.0 9/15/2008 Yes MC-F-08-0162 v1.0 11/24/2008 Yes NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 7 of 11 MC-F-08-0194 v1.0 12/19/2008 No Non-conservative MC-F-08-0017 v3.0 5/22/2009 Yes MC-F-10-0003 v1.0 2/3/2010 Yes MC-F-10-0037 v1.0 2/10/2010 Yes MC-F-10-0005 v1.0 2/11/2010 Yes MC-F-10-0094 v1.0 6/11/2010 Yes MC-F-10-0127 v1.0 12/7/2010 Yes MC-F-08-0026 v1.0 12/20/2010 Yes MC-F-11-0022 v1.0 6/28/2011 Yes MC-F-11-0090 v1.0 11/9/2011 Yes MC-F-12-0002 v1.0 3/12/2012 Yes CCN-F-11-0003 v3.0 8/2/2012 Yes MC-F-12-0031 v1.0 10/8/2012 Yes MC-F-12-0086 v2.0 4/11/2013 Yes MC-F-11-0077 v1.0 4/18/2013 Yes MC-F-12-0071 v3.0 8/1/2013 Yes MC-F-14-0029 v1.0 5/5/2014 No Non-conservative MC-F-13-0087 v1.0 10/15/2014 Yes MC-F-07-0050 v2.0 10/31/2014 Yes MC-F-14-0009 v1.0 2/17/2015 Yes MC-F-15-0051 v1.0 4/9/2015 No Non-conservative
- 1. Determination of 4kV Minimum Expected Voltage The LOCA loading condition, Case 1.4, was performed with the assumed minimum expected 230kV switchyard voltage of 101.0% to establish the minimum expected 4kV bus voltage. This resulted in Minimum Expected Voltages (MEV) of 93.31% for Bus 1F and 93.26% for Bus 1G, as seen in Attachment 1. All safety-related loads had adequate voltage levels for this case.
Table 3. Minimum Expected 4kV Steady-State Voltage with 230kV Grid at 101%.
ETAP Study 230kV Reference 4.16kV Min. Expected Train Case Bus Voltage Voltage (Attach. 3) 1F Load Flow 93.31%
101.0%
1G Case 1.4 93.26%
- 2. Determination of 4kV Minimum Required Voltage and Minimum Starting Voltages Normal steady-state, LOCA steady-state, LOCA group motor starting, and individual motor starting cases were studied to determine the lowest 4kV bus voltage that could supply adequate voltage to all safety-related loads. Based on the existing calculations and the incorporation of outstanding modifications (MCs), the limiting component was found for each train, as summarized in Table 4. Based on the required starting or steady-state voltage of this component, the corresponding pre-start or steady-state voltage at its relative 4kV bus was determined to be the MRV. This MRV was NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 8 of 11 considered for all study cases to verify that all other components achieved adequate voltage to perform the required safety functions. The lowest voltage at the 4kV bus during the LOCA group motor start at the MRV is the MSV (maximum value for the existing LOSP Relay dropout setting).
Table 4. Minimum Pre-start and Starting Voltages for LOCA Group Start Motors.
(See Attachment 1) 4.16kV Bus MRV 4.16kV Bus MSV Limiting ETAP Limiting Train (t=0-) (t=0+) Study Case Device(s)
Motor Starting E4 MOV 3024 A, 1F 88.92% 81.93%
5F LOCA Start E5 MOV 3024 B Motor Starting B4 MOV 2769B, 1G 88.60% 81.19%
5G LOCA Start C2 MOV 3478B The LOCA safety injection group motor starting scenario was simulated in Case 5F LOCA Start with Bus 1F pre-start voltage forced to the MRV of 88.92%. All safety-related loads fed by Bus 1F maintained adequate starting voltage.
The LOCA motor starting study case 5G LOCA Start was performed with the Bus 1G pre-start voltage forced to the MRV of 88.60%. All safety-related loads fed by Bus 1G maintained adequate starting voltage, except the 3232 MOVs and MOV 3318A on 600V MCC 1V. The 3232 MOVs are acceptable per calculation SE-91-1925-14-PE (Reference 14), as the maximum load occurs at the end of the close of the stroke when the MOVs are already running (see Assumption 3). MOV 3318A would achieve the required voltage by replacement of the thermal overload (TOL) heater with one of a lower resistance.
The post safety injection groups MOV Group A (7F LOCA ST A and 7G LOCA ST A) and MOV Group B (4F MOV START and 4G MOV START) case runs were performed with the 4kV buses forced to their respective MRV. All MOVs in these test groups were capable of starting and maintained adequate terminal voltage.
The normal steady-state cases 1.3F and 1.3G were performed with the 4kV buses forced to their respective MRV. All safety-related loads have positive voltage margin in this scenario.
The LOCA steady-state cases 1.4F and 1.4G were performed with the 4kV buses forced to their respective MRV. All safety-related loads have positive voltage margin in this scenario.
Finally, the individual motor starting cases (4F Individual and 4G Individual) were performed with the 4kV buses forced to their respective MRV. All safety-related loads were capable of starting and maintained adequate terminal voltage.
Table 5. ETAP Degraded Grid Case Runs in FNP1V07.
Configuration Module Study Case Load Cat. Gen. Cat. Utility Voltage*
Case_1.3 LF Case 1.3 Normal Min-Exp 101.43%
Case_1.3 LF Case 1.3F Normal DGG-TOL-F 96.86%
Case_1.3 LF Case 1.3G Normal DGG-TOL-G 96.18%
Case_1.4 LF Case 1.4 LOCA.SS Min-Exp 101.45%
Case_1.4 LF Case 1.4F LOCA.SS DGG-F 97.25%
NMP-ES-039- F02 NMP-ES-039-001
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J.M. Farley Nuclear Plant SE-SNC529029-001 9 of 11 Case_1.4 LF Case 1.4G LOCA.SS DGG-G 97.01%
Case_1.4 MS 4F MOV Start LOCA.SS DGG-F 97.25%
Case_1.4 MS 4G MOV Start LOCA.SS DGG-G 97.01%
Case_1.4 MS 4FIndividual LOCA.SS DGG-F 97.25%
Case_1.4 MS 4GIndividual LOCA.SS DGG-G 97.01%
Case_1.5 MS 5F LOCA Strt LOCA.ST DGG-F 96.30%
Case_1.5 MS 5G LOCA Strt LOCA.ST DGG-G 96.08%
Case_1.7 MS 7F LOCA ST A MOV Group A MOV Grp A-F 97.22%
Case_1.7 MS 7G LOCA ST A MOV Group A MOV Grp A-G 96.96%
- Utility voltage is the ETAP input in percent of 230kV representing the voltage behind the system impedance. Actual 230kV switchyard voltage in each plant configuration and loading category is lower than these values.
Refer to Attachment 1 for a summary of safety-related load voltages and Attachments 2 through 4 for ETAP output results for the case studies shown in Table 5. See Table 6 for a list of motors and MOVs listed in Attachment 1 with less than 0.5% margin between their minimum voltage requirements and their degraded motor starting or steady-state voltages from the above case studies.
Table 6. Low Degraded Voltage Margin Motors and MOVs per Attachment 1.
Motor Name Case Study Voltage Req. Voltage Margin MOV 8803A MS 1.5F 75.30% 75.78% 0.48%
MOV 3024A MS 1.5F 72.87% 72.87% 0.00%
MOV 3024B MS 1.5F 72.87% 72.87% 0.00%
LCV 0115B MS 1.5F 74.96% 75.42% 0.46%
MOV V516 MS 1.5G 75.09% 75.59% 0.50%
MOV 8803B MS 1.5G 68.35% 68.76% 0.41%
MOV 8100 MS 1.5G 68.35% 68.63% 0.28%
MOV 3232A MS 1.5G 73.19% 71.32% -1.87%*
MOV 3232B MS 1.5G 68.02% 66.29% -1.73%*
MOV 3232C MS 1.5G 68.02% 66.29% -1.73%*
LCV 0115D MS 1.5G 68.35% 68.74% 0.39%
MOV 3318A MS 1.5G 70.00% 69.93% -0.07%**
MOV 2769B MS 1.5G 68.65% 68.65% 0.00%
MOV 3478B MS 1.5G 70.41% 70.41% 0.00%
Ctrl Rm Press Supply Fan B MS 1.5G 74.00% 74.23% 0.23%
Ctrl Rm HVAC Blower 1B LF 1.4G 90.00% 90.12% 0.12%
Ctrl Rm Rad Monitor B LF 1.3G 90.00% 88.31% -1.69%***
- see Assumption 3 for undervoltage justification
- recommended for TOL replacement
- see Attachment 1, Note 6 for undervoltage justification
- 3. Determination of DVR Time Delay The safety injection group motors (5F LOCA Start and 5G LOCA Start motors) were modeled in ETAP with available dynamic data from SE-90-1845-2-PE (Reference 12). A NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 10 of 11 transient analysis was performed with the prestart voltage at the 4kV buses set to the MRV. As shown in transient analysis plots in Attachment 5, all SI motors were capable of starting and reaching full speed within 6.5 seconds. Therefore, a DVR time delay of greater than 6.5 seconds is required. In this scenario, if the grid conditions do not recover and the relay does not reset, the DVR is expected to time out and transfer the loads to the diesel generators. In the ETAP transient analysis of the safety injection with the grid at 101%, the 4kV Bus 1F and 1G voltages recover above the MEV faster than the DVR time delay of 6.5 seconds. In this scenario, the DVR would reset, preventing a spurious trip from the offsite power source.
Additionally, during a sustained degraded voltage condition concurrent with a LOCA, the DVR must trip before the diesel generator start time of 12 seconds as specified in the FSAR. The DVR must also trip before any thermal overload (TOL) relays trip from overcurrent. Per Attachment 6, the TOL for LCV0115B has an expected trip time of less than 12 seconds during starting with a voltage below its individual motor starting requirement. MOV TOL trip times were calculated as the average trip time from calculation SE-94-0-0378-001, Attachment 4 (Reference 16) corresponding to the TOL starting multiple calculated per the methodology of SE-94-0-0378-001 multiplied by the MOVs minimum voltage requirement for motor starting (see Attachment 1). TOL trip times for safety-related pumps and fans were calculated similarly in Attachment 6 using data from calculations SE-94-0-0378-001 (Reference 16) and SE-90-1714-12, Attachments 4 and 5 (Reference 18). This timing analysis yields a minimum TOL trip time of 11.5 seconds (at LCV0115B).
. . 9400378001
=
where = 1.25 . ()
Note that trip times for overcurrent relays (OCRs) were not considered for the DVR maximum time settings because the 4kV safety injection motors with OCRs are capable of starting at voltages as low as 75%. Below this voltage the existing LOSP Relay should be expected to trip prior to any OCR. See Figure 2 for a visualization of degraded voltage protection.
Given the above constraints, the DVRs must have a time setting between analytical limits of 6.5 seconds and 11.5 seconds. Considering the need to keep safety-related loads on the grid as long as possible while also preventing safety-related motors from tripping due to extended overload conditions, this calculation recommends a setting of 9.0 seconds. Anticipated maximum relay drift is 0.82% of setting per Design Input 3. This yields an upper allowable value for the timing function of 11.4 seconds (11.5 sec./100.82%) and a lower allowable value of 6.6 seconds (6.5 sec./99.18%).
Accounting for calibration tolerances of +/-0.5 seconds per Assumption 5 there is sufficient operating range for a setting of 9.0 seconds. Instrument calibration accuracy, radiation, and seismic tolerances are all assumed to be negligible.
NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 11 of 11 Table 7. DVR Time Delay Operating Range (seconds).
Lower Nominal Upper Analytical Allowable Calib. Trip Calib. Allowable Analytical Limit Value Limit Setpoint Limit Value* Limit 6.5 6.6 8.5 9.0 9.5 11.4 11.5
- Tech. Spec. DVR Time Setting Requirement 95.00%
93.00% MEV DVR RESET 91.00% DVR DROPOUT 89.00% MRV 87.00%
85.00%
83.00% Grid at 101%
81.00% 4kV Pre-Start at MRV MSV 79.00% Existing LOSP Tap 77.00% Setting per Reference 11 75.00%
-0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 Figure 2. Degraded voltage protection scheme.
Attachments:
- 1. Summary of Steady-State and Starting Voltages at Minimum Required Voltage
- 2. ETAP Output Reports - NORMAL Load Flow (Configuration Case 1.3)
- 4. ETAP Output Reports - Motor Starting (Configuration Cases 1.4, 1.5, and 1.7)
- 5. Safety Injection Transient Plots
- 6. Thermal Overload Trip Time Tables
Joseph M. Farley Nuclear Plant, Units 1 and 2 Technical Specification 3.3.5 Loss of Power Diesel Generator Start Instrumentation Supplement to License Amendment Request Enclosure 2 FNP Unit 2 Calculation SE-SNC529029-002 Minimum Expected Voltage Study (Attachments to calculation not included)
SOUTHERN COMPANY A Southern Nuclear Design Calculation En*ro to&- !llur'"'riJ' Calculation Number:
SE-SNC529029-002 Plant: I Unit: I Discipline:
J.M. Farley Nuclear Plant
Title:
Unit 2 Minimum Expected Voltage Study 01 ltl2 01&2 I
Subject:
Electrical AC System Analysis Purpose I Objective:
Determine safe operating limits of Unit 2 under degraded grid conditions System or Equipment Tag Numbers:
R01,R11,R15,R16,R17 Contents Topic Page Attachments #of (Computer Printouts, Technical Papers, Pages Sketches, Correspondence)
Version History 1 1. Summary of Steady-State and Starting 9
Design Inputs 1 Voltages at Minimum Required Voltage References 1 2. ETAP Output Reports- NORMAL Load Flow 91 Purpose of Calculation 2 3. ETAP Output Reports - LOCA Load Flow 99 Summary of Conclusions 2 4. ETAP Output Reports - Motor Starting 50 Methodology 4 5. Safety Injection Transient Plots 1 Assumptions 5 6. Thermal Overload Trip Time Tables 2 Acceptance Criteria 6 7. AC Voltage Drop from PT to DVR 1 Body of Calculation 6 Total# of Pages including 265 cover sheet & Attachments:
Nuclear Qualit Level It! Safe -Related D Version Record Version Originator Reviewer Approval1 Approval2 No. Description Prlnt.d Na11111 lniUaJ I Data Printed Name lniUal/ Data Prtnt.d Name lniUal/ Data Prlnt.c!Name lniUal/ Data .
Chris Harwell Matt Lane Kevin Uttrell J...,!-11'4 ,1/ltrlt.t Y' 1.0 Issued per RER SNC529029, v1.0 c..t~
,,~)1{"
~
w~~~/(f ~V-J (,,,~ ,,.; ht11 6-J'I-15' Notes: An OE search has been performed and the results are documented m the Methodology Section.
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 1 of 11 Version History:
Version 1.0: Initial version issued for RER SNC529029.
Design Inputs:
- 1. SE-94-0470-007, Ver. 7.0, Unit 2 As-Built Load Study: Primary calculation input; source of ETAP model and methodology used for case study runs.
- 2. SE-94-0470-005, Ver. 6.0, Unit 2 Load Study Summary: LOCA starting and steady-state requirements tables modified for use as Attachment 1 of this calculation.
- 3. SJ-SNC529029-001, Ver. 1.0, Determination Of Setpoints, Reset Points, And Loop Uncertainties For 4160V Safety-Related Degraded Voltage Relay (DVR) Loops (Buses 1F, 2F, 1G And 2G)
References:
- 1. GDC 17, General Design Criteria for Nuclear Power Plants 17
- 2. IEEE Standard 399-1997, IEEE Recommended Practice for Industrial and Commercial Power Systems Analysis
- 3. NRC Regulatory Issue Summary 2011-12, Revision 1, Adequacy of Station Electric Distribution System Voltages: Guidance for degraded grid analysis acceptance criteria and methodology
- 4. Farley Nuclear Plant Units 1 & 2 Tech Spec Bases, Rev. 66
- 5. Farley Nuclear Plant Unit 2 Tech Spec, Amendment 193
- 6. Farley Nuclear Plant Units 1 & 2 FSAR, Rev. 26, March 2015
- 7. SM-90-1653-002, Ver. 23.0, Reduced Voltage Torque/Thrust Capability for Gate &
Globe Valves in the FNP MOV Program
- 8. SM-90-1653-009, Ver. 8.0, Reduced Voltage Torque Capability for Butterfly Valves in the FNP MOV Program
- 9. SM-1053039201-001, Ver. 1.0, Develop Design Basis Calculations for the Penetration Room Filter Dampers
- 10. DOEJ-FRSNC529029-M001, Ver. 1.0, Evaluation of Reduced Voltage Requirements for Motor Operated Valves for use in the Degraded Voltage Protection Plan
- 11. E-035.02.A, Ver. 7.0, Setting of Protective Relays for 4.16kV Auxiliary Power System
- 12. SE-90-1845-2-PE, Ver. 8.0, Large, Small, and SBO Diesel Dynamic Study
- 13. SE-91-1976-1, Ver. 6.0, Motor Starter Control Circuit Study
- 14. SE-91-1925-14-PE, Ver. 1.0, MOV3232A,B,C: Terminal Voltage at End of Stroke
- 15. SE-99-9472-001, Ver. 1.0, Stability Review for LOSP/DGG Relay Operation
- 16. SE-94-0-0378-001, Ver. 5.0, MOV Combination Starter Component Sizes and Settings
- 17. SE-99-0-2010-001, Ver. 0.0, Verification Package for Computer Software Used to Calculate MOV Thermal Overload Heater Sizes
- 18. SE-90-1714-12, Ver. 4.0, Overload Heater Sizing and Resistance
- 20. 1995 SER, February 23, 1995, Safety Evaluation for Degraded Grid Voltage Relay Set Points
- 21. GEH-1768G, GE Instructions: Undervoltage Relays
- 22. MC-F-06-0057, Ver. 1.0
- 23. MC-F-06-0144, Ver. 1.0 NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 2 of 11
- 24. MC-F-07-0015, Ver. 1.0
- 25. MC-F-07-0081, Ver. 1.0
- 26. MC-F-07-0117, Ver. 1.0
- 27. MC-F-08-0077, Ver. 1.0
- 28. MC-F-08-0092, Ver. 1.0
- 29. MC-F-08-0193, Ver. 1.0
- 30. MC-F-09-0044, Ver. 1.0
- 31. MC-F-09-0073, Ver. 1.0
- 32. MC-F-09-0075, Ver. 1.0
- 33. MC-F-09-0077, Ver. 1.0
- 34. MC-F-09-0172, Ver. 1.0
- 35. MC-F-10-0064, Ver. 1.0
- 36. MC-F-10-0057, Ver. 1.0
- 37. MC-F-10-0071, Ver. 1.0
- 38. MC-F-10-0132, Ver. 2.0
- 39. MC-F-10-0133, Ver. 1.0
- 40. MC-F-11-0007, Ver. 1.0
- 41. MC-F-11-0005, Ver. 1.0
- 42. MC-F-11-0038, Ver. 1.0
- 43. MC-F-11-0080, Ver. 1.0
- 44. MC-F-12-0028, Ver. 1.0
- 45. MC-F-12-0058, Ver. 1.0
- 46. MC-F-12-0064, Ver. 1.0
- 47. MC-F-13-0031, Ver. 1.0
- 48. MC-F-13-0067, Ver. 1.0
- 49. MC-F-14-0021, Ver. 1.0
- 50. CCN-F-13-0001, Ver. 1.0
- 51. CR 10063545
- 52. CAR 257139
- 53. 57SV-S32-002-1, Emergency Buses 1E, 1F, and 1G Undervoltage Relay Instrument FT&C, Attachment 3.
Purpose of Calculation:
The purpose of this calculation is to determine the operating range of Farley Nuclear Plant Unit 2 under degraded voltage conditions at the 230kV grid to meet the requirements of safety-related loads using the guidance in Regulatory Issue Summary RIS 2011-12, Revision 1 (Reference 3). This operating range is used by other calculations to determine Degraded Voltage Relay (DVR) settings to automatically transfer safety-related loads from an unacceptable offsite power source to an onsite power source.
Summary of
Conclusions:
- 1. The minimum voltage that meets the steady-state requirements for all safety-related loads during the Normal and LOCA loading cases for Farley Unit 2 is determined, and is documented in Table 1a as the Minimum Required Voltage (MRV). Refer to Attachments 2 and 3 for ETAP output reports.
NMP-ES-039- F02 NMP-ES-039-001
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J.M. Farley Nuclear Plant SE-SNC529029-002 3 of 11
- 2. The required starting voltage at the safety-related motors and MOVs is satisfied for the motor starting cases established in calculation SE-94-0470-005 (Design Input 2). Refer to Attachment 4 for ETAP output reports.
- 3. Some of the safety-related MCCs have voltages below the minimum level required for motor control circuits during the safety injection group motor start; however, per calculation SE-91-1976-1 (Reference 13), these MCCs are acceptable because with the 4kV buses at the MRV, they have the minimum required relay pickup voltage to energize upon an SI signal prior to the motor starting transient. Additionally, load voltages remain above the relay drop-out voltage. See Attachment 1 for motor starting bus voltages.
- 4. The MRV, shown in Table 1a, is lower than the DVR Lower Analytical Limit (LAL). This LAL is selected to provide margin below the DVR setpoint uncertainty range determined in Design Input 3 and above the MRV. Thus the dropout voltage of each DVR will be set such that the minimum tolerance is above the MRV for the 4160V buses 2F and 2G.
- 5. The Minimum Expected Voltage (MEV), shown in Table 1a, is higher than the DVR Upper Analytical Limit (UAL). This UAL is selected to provide margin above the DVR setpoint uncertainty range determined in Design Input 3 and below the MEV. Thus the reset voltage of each DVR will be set such that the maximum tolerance is below the MEV for the 4160V buses 2F and 2G.
- 6. The total available electrical margin available is 1.54% and 0.99% for 4160V buses 2F and 2G, respectively, per the results in Table 1a.
- 7. The DVR time delay should be set, with tolerances, so that the time is not less than the Safety Injection (SI) Transient Time, and not greater than the minimum thermal overload (TOL) relay trip time, as shown in Table 1b. It is the recommendation of this calculation to set the DVR time delay at 8.0 seconds to keep the safety-related loads on the grid as long as possible while also preventing safety-related motors from tripping due to extended overload conditions. Safety Injection Transient plots are included in Attachment 5, and TOL trip times for SI motors when below the MSV are listed in Attachment 6.
- 9. The dropout voltage of each LOSP Relay is below the Minimum Starting Voltage (MSV) shown in Table 1a for the 4160V buses 2F and 2G, which occurs immediately after a LOCA group motor start, so there is no expected interaction between the new DVR and the existing LOSP Relay.
Table 1a. Summary of Unit 2 Degraded Voltage Relay Operating Range Results.**
4.16kV Bus 4.16kV Bus DVR Margin 4.16kV 4.16kV MEV DVR UAL MRV DVR LAL (MEV-MRV)
Bus Bus MSV (Attach. 2) (Attach. 1) - (UAL-LAL) 2F 93.44% 92.67% 88.71% 89.48% 81.65% 1.54%
2G 93.69% 93.19% 89.50% 89.99% 82.36% 0.99%
Table 1b. Summary of Unit 2 DVR Timing Analysis.
4.16kV SI Transient Start Time TOL Trip Time DVR Trip DVR Time Delay Bus (Attach. 5) (Attach. 6) Setpoint Allowable Value*
2F 6.0 seconds 10.0 seconds 8.0 seconds 9.9 seconds 2G
- Tech. Spec. DVR Time Setting Requirement NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 4 of 11 Methodology:
The computer model of Farley Unit 2, FNP2V01, was developed with ETAP Version 12.6.0N software package for calculation SE-94-0470-007 (Design Input 1). This calculation uses ETAP software to perform analysis of the auxiliary system including load flow, motor starting, and transient studies. Refer to the ETAP User Guide 12.6 for additional information regarding the ETAP program.
Version 6.0 of calculation SE-94-0470-007 ETAP model (FNP2V01) was utilized for this calculation. While this study was being finalized, the Unit 2 load study model was also being finalized. Re-analysis utilizing the latest file (FNP2V02) was not required per discussions with SNC.
Before the ETAP model was used for this study, outstanding modification calculations (MCs) against base calculation (BC) SE-94-0470-007 (Design Input 1) were merged into the base revision in order of MC approval dates. See Table 2 in the calculation body for a detailed list of merged MCs. CR 10063545 (Reference 51) was addressed utilizing CAR 257139 (Reference 52) load changes, which were also incorporated into the ETAP model as part of this calculation. The ETAP model was then used to determine several values at the 4kV buses 2F and 2G: the Minimum Expected Voltage, the Minimum Required Voltage, the Minimum Starting Voltage, and the Safety Injection Transient Time (See example of the relationship of these values as shown in Figure 1).
The methodology for each is described below.
- 1. Minimum Expected Voltage (MEV): The MEV is calculated as the 4kV bus voltage during LOCA steady-state with a 230kV switchyard voltage of 101.0%. In the Farley Unit 2 ETAP model FNP2V01, this is the Load Flow Study Case 2.4.
- 2. Minimum Required Voltage (MRV): The MRV is the maximum requirement of the following three calculations.
- a. Using maximum expected non-accident bus loading, determine minimum acceptable steady-state voltage for normal operation of Class 1E loads. This was performed using ETAP load flow study cases 2.3F and 2.3G.
- b. Using maximum expected accident loading, determine the minimum pre-start voltage that provides acceptable Class 1E motor starting (e.g. during LOCA group motor starting). This was performed using ETAP load flow study cases 2.4F and 2.4G.
- c. Using maximum expected accident loading, determine the minimum steady-state voltage that provides acceptable Class 1E motor operation and starting for individual motors. This was performed using ETAP motor starting study cases 4F MOV Start, 4G MOV Start, 5F LOCA Start, 5G LOCA Start, 7F LOCA ST A, and 7G LOCA ST A.
- 3. Minimum Starting Voltage (MSV): The MSV is calculated as the lowest voltage at the 4kV bus during a LOCA group start transient (ETAP motor starting study cases 5F LOCA Start and 5G LOCA Start) with the pre-start voltage at the MRV.
- 4. Safety Injection Transient Time: The SI Transient Time is calculated as the minimum time for the SI group motors to start and reach steady-state with the 4kV buses at the NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 5 of 11 MRV. The ETAP Transient Study Case used to analyze the SI group start is developed as a part of this calculation.
MEV MRV SI Transient Time MSV Figure 1. Example SI transient showing location of MEV, MRV, MSV, and SI Transient Time.
The OE search was performed using the following keywords:
ETAP Degraded Grid Relay Date OE Problem Relevance / Action /
Source Impact Resolution 11/19/2009 INPO OE30473: Potential Inaccurate No motors Only applies to Induction Motor Models in ETAP- modeled at older versions of Davis-Besse Unit 2: greater than ETAP. No action The cumulative load increases due 100% loading. is required.
to induction machine modeling techniques may result in non-conservative AC Power System Analyses. For motors operating at greater than 100 percent, allowing efficiency at 100 percent motor load to adjust results in a non-conservative estimate (under prediction) of EDG loading due to the ETAP extrapolation of motor efficiency beyond 100 percent loading.
Assumptions:
- 1. A minimum expected grid voltage of 101.0% at the 230kV Reference Bus is assumed and utilized in the ETAP model based on contingency studies defined by the FSAR (Reference 6).
- 2. Loads listed in Attachment 1 with steady-state voltages that do not have motor starting criteria are assumed to be able to endure a transient motor starting situation.
- 3. Low motor starting voltage for the 3232 MOVs on 600V MCC 2V can be considered acceptable during block starting since the MOVs start with no load. Per SCS Calculation NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 6 of 11 SE-91-1925-14-PE (Reference 14), the maximum load occurs at the end of the close of the stroke when the motors are already running.
- 4. A constant grid impedance of 0.87+j1.125 percent of 100MVA base is assumed and utilized in the ETAP model per calculation SE-94-0470-007, Attachment C (Design Input 1).
- 5. ABB 27N calibration limits are determined to be +/-0.5 seconds from the Plant Hatch Surveillance Procedure for degraded voltage alarm relays 57SV-S32-002-1, Emergency Buses 1E, 1F, and 1G Undervoltage Relay Instrument FT&C, Attachment 3 (Reference 53).
Acceptance Criteria:
- 1. The required steady-state voltages at the motor terminals are established in calculation SE-94-0470-005 (Design Input 2). Non-1E motors/loads are allowed to be below 90%
rated voltage, since they are not required to mitigate a design basis event.
- 2. The required starting voltages at the safety-related motors are established in calculation SE-94-0470-005 (Design Input 2). All safety-related motors must be capable of starting at the corresponding MRV.
- 3. The required MOV starting voltages are established in mechanical torque calculations SM-90-1653-002 (Reference 7), SM-90-1653-009 (Reference 8) and SM-1053039201-001 (Reference 9), as listed in SE-94-0470-005 (Design Input 2). These starting requirements have been updated by DOEJ-FRSNC529029-M001 (Reference 10). All safety-related MOVs must be capable of starting at the corresponding MRV.
- 4. With the 4kV bus pre-start voltage at the MRV, the SI transient time should be less than the minimum TOL trip time to prevent safety-related equipment from stalling or tripping on overcurrent during a degraded voltage condition.
- 5. The MRV must be lower than the LAL, and the MEV must be higher than the UAL. The Analytical Limits must be selected to provide margin above and below the setpoint uncertainty range determined in Design Input 3.
Body of Calculation:
ETAP was used to simulate normal and accident conditions with a concurrent degraded grid condition. Outstanding MCs and CCNs (References 22-50) against SE-94-0470-007 (Design Input 1) were merged into the ETAP base revision of Farley Unit 2 model FNP2V01 in accordance with Table 2 before any case studies were analyzed. The methodology used in Design Input 1 was followed to set up the ETAP study cases. The 230kV source voltage was modified to obtain the desired voltage at the 4kV bus being studied for each case.
Table 2. List of Outstanding MCs Merged into ETAP Model Base Revision.
Approval MC Number Date Merged Notes MC-F-06-0057 v1.0 3/22/2006 No Removes load MC-F-06-0144 v1.0 9/28/2006 Yes MC-F-07-0015 v1.0 2/07/2007 No Removes load MC-F-07-0081 v1.0 3/11/2008 Yes MC-F-07-0117 v1.0 12/13/2007 Yes NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 7 of 11 Table 2. List of Outstanding MCs Merged into ETAP Model Base Revision.
Approval MC Number Date Merged Notes MC-F-08-0092 v1.0 9/15/2008 Yes MC-F-08-0077 v1.0 6/6/2008 Yes MC-F-08-0193 v1.0 12/19/2008 No Removes load MC-F-09-0044 v1.0 3/23/2009 Yes MC-F-09-0073 v1.0 7/30/2009 Yes Merged because MDC is as-built MC-F-09-0075 v1.0 7/30/2009 Yes MDC is closed, but not yet closed by site MC-F-09-0077 v1.0 7/30/2009 Yes Merged because MDC is as-built MC-F-09-0172 v1.0 12/30/2009 Yes MC-F-10-0064 v1.0 4/13/2010 Yes MDC is closed, but not yet closed by site MC-F-10-0071 v1.0 6/13/2010 Yes MC-F-10-0057 v1.0 6/13/2010 Yes MC-F-10-0133 v1.0 12/7/2010 Yes MC-F-11-0007 v1.0 2/21/2011 No Reduces load MC-F-11-0005 v1.0 3/10/2011 Yes MDC is closed, but not yet closed by site MC-F-10-0132 v2.0 8/17/2011 Yes MC-F-11-0038 v1.0 10/12/2011 Yes MC-F-12-0028 v1.0 10/8/2012 Yes MC-F-12-0064 v1.0 2/7/2013 Yes CCN-F-13-0001 v1.0 3/5/2013 Yes MC-F-11-0080 v1.0 4/18/2013 Yes MC-F-13-0031 v1.0 9/5/2013 No Removes load MC-F-14-0021 v1.0 11/7/2014 Yes MC-F-12-0058 v1.0 12/18/2014 Yes MC-F-13-0067 v1.0 2/9/2015 Yes
- 1. Determination of 4kV Minimum Expected Voltage The LOCA loading condition, Case 2.4, was performed with the assumed minimum expected 230kV switchyard voltage of 101.0% to establish the minimum expected 4kV bus voltage. This resulted in minimum expected 4kV voltages (MEV) of 93.44% for Bus 2F and 93.69% for Bus 2G, as seen in Attachment 1. All safety-related loads had adequate voltage levels for this case.
Table 3. Minimum Expected 4kV Steady-State Voltage with 230kV Grid at 101%.
ETAP 230kV Reference 4.16kV Min. Expected Train Study Case Bus Voltage Voltage (Attach. 3) 2F Load Flow 93.44%
101.0%
2G Case 2.4 93.69%
NMP-ES-039- F02 NMP-ES-039-001
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J.M. Farley Nuclear Plant SE-SNC529029-002 8 of 11
- 2. Determination of 4kV Minimum Required Voltage and Minimum Starting Voltages Normal steady-state, LOCA steady-state, LOCA group motor starting, and individual motor starting cases were studied to determine the lowest 4kV bus voltage that could supply adequate voltage to all safety-related loads. Based on the existing calculations and the incorporation of outstanding modifications (MCs), the limiting component was found for each train, as summarized in Table 4. Based on the required starting or steady-state voltage of this component, the corresponding pre-start or steady-state voltage at its relative 4kV bus was determined to be the MRV. This MRV was considered for all study cases to verify that all other components achieved adequate voltage to perform the required safety functions. The lowest voltage at the 4kV bus during the LOCA group motor start at the MRV is the MSV (maximum value for the LOSP Relay dropout setting).
Table 4. Minimum Pre-start and Starting Voltages for LOCA Group Start Motors.
(See Attachment 1) 4.16kV Bus MRV 4.16kV Bus MSV Limiting ETAP Train Limiting Device (t=0-) (t=0+) Study Case Motor Starting B3 Serv Wtr MOV 515 2F 88.71% 81.65%
5F LOCA Start B4 Serv Wtr MOV 517 Motor Starting B4 MOV 2769B, 2G 89.50% 82.36%
5G LOCA Start C2 MOV 3478B The LOCA safety injection group motor starting scenario was simulated in case 5F LOCA Start with Bus 2F pre-start voltage forced to the MRV of 88.71%. All safety-related loads fed by Bus 2F maintained adequate starting voltage.
The LOCA safety injection group motor starting scenario was simulated in case 5G LOCA Start with Bus 2G pre-start voltage forced to the MRV of 89.50%. All safety-related loads fed by Bus 2G maintained adequate starting voltage, except the 3232 MOVs on 600V MCC 2V. The 3232 MOVs are acceptable per calculation SE-91-1925-14-PE (Reference 14), as the maximum load occurs at the end of the close of the stroke when the MOVs are already running (see Assumption 3).
The post safety injection groups MOV Group A (7F LOCA ST A and 7G LOCA ST A) and MOV Group B (4F MOV START and 4G MOV START) case runs were performed with the 4kV buses forced to their respective MRV. All MOVs in these test groups were capable of starting and maintained adequate terminal voltage.
The normal steady-state cases 2.3F and 2.3G were performed with the 4kV buses forced to their respective MRV. All safety-related loads have positive voltage margin in this scenario.
The LOCA steady-state cases 2.4F and 2.4G were performed with the 4kV buses forced to their respective MRV. All safety-related loads have positive voltage margin in this scenario.
NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 9 of 11 Finally, the individual motor starting cases (4F Individual and 4G Individual) were performed with the 4kV buses forced to their respective MRV. All safety-related loads were capable of starting and maintained adequate terminal voltage.
Table 5. ETAP Degraded Grid Case Runs in FNP2V01.
Configuration Module Study Case Load Cat. Gen. Cat. Utility Voltage*
Case_2.3 LF Case 2.3 Normal Min-Exp 101.40%
Case_2.3 LF Case 2.3F Normal DGG-TOL-F 96.25%
Case_2.3 LF Case 2.3G Normal DGG-TOL-G 96.63%
Case_2.4 LF Case 2.4 LOCA.SS Min-Exp 101.43%
Case_2.4 LF Case 2.4F LOCA.SS DGG-F 96.90%
Case_2.4 LF Case 2.4G LOCA.SS DGG-G 97.40%
Case_2.4 MS 4F MOV Start LOCA.SS DGG-F 96.90%
Case_2.4 MS 4G MOV Start LOCA.SS DGG-G 97.40%
Case_2.4 MS 4FIndividual LOCA.SS DGG-F 96.90%
Case_2.4 MS 4GIndividual LOCA.SS DGG-G 97.40%
Case_2.5 MS 5F LOCA Strt LOCA.ST DGG-F 95.95%
Case_2.5 MS 5G LOCA Strt LOCA.ST DGG-G 96.48%
Case_2.7 MS 7F LOCA ST A MOV Grp A MOV Grp A-F 96.70%
Case_2.7 MS 7G LOCA ST A MOV Grp A MOV Grp A-G 97.23%
- Utility voltage is the ETAP input in percent of 230kV representing the voltage behind the system impedance. Actual 230kV switchyard voltage in each plant configuration and loading category is lower than these values.
Refer to Attachment 1 for a summary of safety-related load voltages and Attachments 2 through 4 for ETAP output results for the case studies shown in Table 5. See Table 6 for a list of motors and MOVs listed in Attachment 1 with less than 0.5% margin between their minimum voltage requirements and their degraded motor starting or steady-state voltages from the above case studies.
Table 6. Low Degraded Voltage Margin Motors and MOVs per Attachment 1.
Motor Name Case Study Voltage Req. Voltage Margin MOV 3478A MS 2.5F 75.99% 76.41% 0.42%
MOV 2769A MS 2.5F 73.93% 74.34% 0.41%
MOV V515 MS 2.5F 84.86% 84.86% 0.00%
MOV V517 MS 2.5F 84.86% 84.86% 0.00%
MOV 8811A MS 2.4F MOV 78.78% 78.95% 0.17%
Solatron Voltage Reg. LF 2.4F 77.00% 77.10% 0.10%
Mult Relay Cab 1A LF 2.4F 88.19% 88.41% 0.22%
MOV 3024C MS 2.5G 65.57% 65.85% 0.28%
MOV 3024D MS 2.5G 66.09% 66.69% 0.60%
MOV 8100 MS 2.5G 68.70% 68.94% 0.24%
MOV 3232A MS 2.5G 72.05% 71.28% -0.76%*
MOV 3232B MS 2.5G 72.57% 71.56% -1.01%*
MOV 3232C MS 2.5G 73.24% 72.48% -0.76%*
MOV 3318A MS 2.5G 70.00% 71.74% 1.74%
MOV V516 MS 2.5G 75.21% 75.40% 0.19%
NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 10 of 11 Table 6. Low Degraded Voltage Margin Motors and MOVs per Attachment 1.
Motor Name Case Study Voltage Req. Voltage Margin MOV 2769B MS 2.5G 68.65% 68.65% 0.00%
MOV 3478B MS 2.5G 70.41% 70.41% 0.00%
Ctrl Rm Press Supply Fan B MS 2.5G 74.00% 74.23% 0.23%
Ctrl Rm Rad Monitor LF 2.3G 90.00% 90.39% 0.39%
L5L Spent Fuel Pool Mon. LF 2.4G 90.00% 90.46% 0.46%
- see Assumption 3 for justification for negative margin
- 3. Determination of DVR Time Delay The safety injection group motors (5F LOCA Start and 5G LOCA Start motors) were modeled in ETAP with available dynamic data from SE-90-1845-2-PE (Reference 12). A transient analysis was performed with the prestart voltage at the 4kV buses set to the MRV. As shown in transient analysis plots in Attachment 5, all SI motors were capable of starting and reaching full speed within 6 seconds. Therefore, a DVR time delay of greater than 6 seconds is required. In this scenario, if the grid conditions do not recover and the relay does not reset, the DVR is expected to time out and transfer the loads to the diesel generators. In the ETAP transient analysis of the safety injection with the grid at 101%, the 4kV Bus 2F and 2G voltages recover above the MEV faster than the DVR time delay of 6 seconds. In this scenario, the DVR would reset, preventing a spurious trip from the offsite power source.
Additionally, during a sustained degraded voltage condition concurrent with a LOCA, the DVR must trip before the diesel generator start time of 12 seconds as specified in the FSAR. The DVR must also trip before any thermal overload (TOL) relays trip from overcurrent. Per Attachment 6, TOLs for five MOVs have expected trip times of less than 12 seconds during starting with a voltage below their individual motor starting requirement. MOV TOL trip times were calculated as the average trip time from calculation SE-94-0-0378-001, Attachment 4 (Reference 16) corresponding to the TOL starting multiple calculated per the methodology of SE-94-0-0378-001 multiplied by the MOVs minimum voltage requirement for motor starting (see Attachment 1). TOL trip times for safety-related pumps and fans were calculated similarly in Attachment 6 using data from calculations SE-94-0-0378-001 (Reference 16) and SE-90-1714-12, Attachments 4 and 5 (Reference 18). This analysis yields a minimum TOL trip time of 10 seconds (at MOV 3232B).
where 1.25 .
Note that trip times for overcurrent relays (OCRs) were not considered for the DVR maximum time settings because the 4kV safety injection motors with OCRs are capable of starting at voltages as low as 75%. Below this voltage the LOSP Relay should be expected to trip prior to any OCR. See Figure 2 for a visualization of degraded voltage protection.
NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 11 of 11 Given the above constraints, the DVRs must have a time setting between analytical limits of 6.0 seconds and 10.0 seconds. Considering the need to keep safety-related loads on the grid as long as possible while also preventing safety-related motors from tripping due to extended overload conditions, this calculation recommends a setting of 8.0 seconds. Anticipated maximum relay drift is 0.82% of setting per Design Input 3. This yields an upper allowable value for the timing function of 9.9 seconds (10.0 sec./100.82%) and a lower allowable value of 6.1 seconds (6.0 sec./99.18%).
Accounting for calibration tolerances of +/-0.5 seconds per Assumption 5 there is sufficient operating range for a setting of 8.0 seconds. Instrument calibration accuracy, radiation, and seismic tolerances are all assumed to be negligible.
Table 7. DVR Time Delay Operating Range (seconds).
Lower Nominal Upper Analytical Allowable Calib. Trip Calib. Allowable Analytical Limit Value Limit Setpoint Limit Value* Limit 6.0 6.1 7.5 8.0 8.5 9.9 10.0
- Tech. Spec. DVR Time Setting Requirement 95.00%
93.00% MEV 91.00% DVR RESET DVR DROPOUT 89.00% MRV 87.00%
85.00% 4kV PreStart at MRV 83.00% Grid at 101%
81.00% MSV 79.00% LOSP Tap Setting 77.00% per Reference 11 75.00%
0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 Figure 2. Degraded voltage protection scheme.
Attachments:
- 1. Summary of Steady-State and Starting Voltages at Minimum Required Voltage
- 2. ETAP Output Reports - NORMAL Load Flow (Configuration Case 2.3)
- 4. ETAP Output Reports - Motor Starting (Configuration Cases 2.4, 2.5, and 2.7)
- 5. Safety Injection Transient Plots
- 6. Thermal Overload Trip Time Table
Joseph M. Farley Nuclear Plant, Units 1 and 2 Technical Specification 3.3.5 Loss of Power Diesel Generator Start Instrumentation Supplement to License Amendment Request Enclosure 3 FNP Units 1 & 2 Calculation SJ-SNC529029-001 Determination of Setpoints (Attachments to calculation not included)
Southern Nuclear Design Calculation SOUTHERN.\_ Calculation Number:
COMPANY EMrD ~vSnw...,_!RwiJ' SJ-SNC529029-001 Plant: 1Unit: 1Discipline:
Farley 01 02 ml1 &2 I&C
Title:
Determination Of Setpoints, Reset Points And Loop Uncertainties
Subject:
For The 4160V Safety-Related Degraded Voltage Relay (DVR) Loops 4160 KV Buses 1F, (Buses 1F, 2F, 1G And 2G) 1G,2F&2G Degraded Voltage Relavs Purpose I Objective:
Determine available margin System or Equipment Tag Numbers:
27F3 (3-1) 27F3 (2-3), 27F3 (1-2t 27G3 (3-1), 27G3 (2-3), 27G3 {1-2)
Contents Topic Page Attachments #of (Computer Printouts, Technical Papers, Pages Sketches Correspondence) "'
Attachment A, As-found/As-left (AF/AL) Analysis P.urpose of Calculation 1 21 of Alarm Relays Summary of Conclusions Attachment B,IB 7.4.1.7-7, ABB Instructions 1 12 Single Phase Voltage Relays Discussion of Methodoloav 3 Functional Description 7 Body of Calculation 8 Design Inputs 23 References 23 Total #of Pages Including 57 cover sheet &Attachments :
Version Record Version No. Desc tlon 1 Issued Note: An OE search has been performed and the results are documented in the Methodology section on page 5.
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 1 of 23 1.0 Purpose The purpose of this calculation is to determine the limiting allowable values, setpoints, reset points, available margin and loop uncertainties for the undervoltage function of the 4160V safety-related degraded voltage relay (DVR) loops (Buses 1F, 2F, 1G and 2G). The DVR relays used in this application have an integral user-settable time delay function. This calculation addresses the undervoltage function of the relay only. The timing function of the relays is address in calculations SE-SNC529029-001 (Reference 4) and SE-SNC529029-002 (Reference 8).
2.0 Summary of
Conclusions:
The limiting allowable values, setpoints, reset points, loop uncertainties and margins for the undervoltage function of the 4160V safety-related DVR loops (Buses 1F, 2F, 1G and 2G) are reflected in tables 1a and 1b below.
Table 1a - Allowable Values, Nominal Setpoints and Uncertainties (Undervoltage Function)
Refer to Figure 1, page 3 for illustrative presentation of Limiting Values Allowable Value Nominal Setpoint Loop Loop Under-At Primary At Relay At Primary At Relay Uncertainty Uncertainty voltage VAC VAC VAC VAC in % (VAC) at Function
(%4160V) (%4160V) 120VAC secondary Bus 1F Upper 3831.80a 3808.00 109.36 108.68 1.11 1.33 (Reset)b: (92.11) (91.54)
Lower 3760.75a 3784.55 107.45 108.13 1.11 1.33 (Trip): (90.40) (90.97)
Bus 1G Upper 3822.00a 3798.20 109.08 108.40 1.11 1.33 (Reset)b: (91.88) (91.30)
Lower 3751.65a 3775.10 107.19 107.86 1.10 1.32 (Trip): (90.18) (90.75)
Bus 2F Upper 3827.95a 3804.15 109.25 108.57 1.11 1.33 (Reset)b: (92.02) (91.45)
Lower 3757.25a 3780.70 107.35 108.02 1.10 1.32 (Trip): (90.32) (90.88)
Bus 2G Upper 3849.30a 3825.50 109.86 109.18 1.12 1.34 (Reset)b: (92.53) (91.96)
Lower 3778.25a 3802.05 107.95 108.63 1.11 1.33 (Trip): (90.82) (91.40)
NOTES:
a) Technical Specification Table 3.3.5-1.2 Loss of Power Diesel Generator Start Instrumentation recommended Allowable Value b) Upper value at primary side (Vp) adjusted to reflect 0.12V voltage drop on the secondary side (cable between the PT and DVR).
The calculated setpoint and allowable values account for an additional margin of 0.22 VAC on the secondary side of the PT (120 VAC buses).
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 2 of 23 Figure 1 - Limiting Values Diagram2 VAC at primary (VAC at relay)
(Vp) (Vr) 3858.82 Upper AL (110.13)
(92.76%)
Technical Specification 3831.801 (109.36)
Upper Allowable Value Reset Upper 3812.201 (108.80)
Calibration Limit Nominal Reset Setpoint 3808.001 (108.68)
Reset Lower 3803.801 (108.56)
Calibration Limit Setpoint Upper 3788.75 (108.25)
Calibration Limit Nominal Setpoint 3784.55 (108.13)
Setpoint Lower 3780.35 (108.01)
Calibration Limit Technical Specification 3760.75 (107.45)
Lower Allowable Value 3726.11 Lower AL (106.47)
(89.57%)
Notes:
- 2. Bus 1F is shown. Buses 1G, 2F and 2G are similar.
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 3 of 23 3.0 Discussion of Methodology Due to the simple configuration of this loop and the use of components traditionally not found in instruments loops, there are very few uncertainty terms that apply to this calculation. The loop consists of a potential transformer and an undervoltage relay with an integral user-settable time delay function. The uncertainties associated with the undervoltage function for the relays listed below are addressed in this calculation:
Bus 1F Bus 1G Bus 2F Bus 2G Q1R43E0001A27F312 Q1R43E0001B27G312 Q2R43E0001A27F312 Q2R43E0001B27G312 Q1R43E0001A27F323 Q1R43E0001B27G323 Q2R43E0001A27F323 Q2R43E0001B27G323 Q1R43E0001A27F331 Q1R43E0001B27G331 Q2R43E0001A27F331 Q2R43E0001B27G331 Due to the functional nature of this loop, the enhanced uncertainty methodology in section A.4.3 of DI-2 is followed as a guideline only. Vendor-provided uncertainty terms are in %
setting. Therefore, where necessary, the upper and lower uncertainty terms are derived separately. These terms are prefixed by a U and L respectively.
The following discussion addresses the justification and assumptions used in determining the applicable uncertainty terms and the channel statistical allowance (CSA) equation.
Each DVR loop consists of a transformer and relay. In order to use terminology consistent with DI-2, for the purposes of this calculation the transformer will be treated as the primary element and the relay as the rack comparator (bistable) instrument. There is no sensor in this loop. The pressure effects normally associated with the sensor will be considered in the calculation of the rack uncertainties (RPE term). Therefore the CSA is defined for this two element loop as:
(RD + RMTE )2 + (RCSA + RMTE )2 + RRA 2 + RTE 2 +
CSA = + ( BIAS + EA)
RPE 2 + PEA 2 + PMA 2 For this application: RCSA and RMTE are considered dependent variables. RRA, RTE, RPE and PEA are considered independent variables with respect to RCSA and RMTE and each other.
RD is not combined with any other term since it is derived from plant data which includes any contributions associated with other error terms including RMTE. Therefore the following equation is used to calculate CSA:
CSA = +/-[(RCSA+RMTE)2 + (RRA)2 + (RTE)2 + (RPE)2 + (RD)2 + (PEA)2]1/2 This calculation takes into consideration the voltage drop between the secondary side of the PT and the DVR. The voltage at the DVR shall be designated as Vr. The voltage at the secondary side of the PT shall be designated as Vs and the voltage at the primary side of the PT shall be designated as Vp.
An iterative method is used to determine the drop out (trip) setpoint (LNTSP), pickup (reset) setpoint (UNTSP) and margin (upper and lower) for the undervoltage function. The goal is to determine a setpoint/reset such that lower margin is 0.2% setting and the upper margin is
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 4 of 23 0.0% setting. The process is as follows (the specific numbers provided below are based on Bus 1F, Table 5):
From DI-4, Table 1a, the upper analytical limit is 92.76% 4160V. This equates to 3858.82V on the primary side (Vp) and 110.25V on the secondary side (Vs) of the transformer. The analytical limit on the secondary side of the transformer is then adjusted to account for a 0.12V voltage drop on the cable between the PT and DVR (assumption 8). Therefore, for the purposes of this calculation the upper analytical limit used for calculating the DVR setpoints is 110.13V (110.25V - 0.12V) at the relay (Vr). From DI-4, Table 1a, the lower analytical limit is 89.57% 4160V. This equates to 3726.11V on the primary side (Vp) and 106.47V on the secondary side (Vs) of the transformer.
A value is chosen for the dropout setpoint (108.13V). Using the formulas from NMP-ES-033-004, the relay uncertainty (LCSA) is determined (1.32V). Then the lower margin (LM) is determined (0.22V). From these derived values, the dropout setpoint at the lower calibration limit is verified to determine that it will support the lower analytical limit without excess margin.
In essence, this means the value for the dropout setpoint minus the relay uncertainty (LCSA) of 1.32V and lower margin (LM) of 0.22V does not fall below the analytical limit. The dropout setpoint at the lower calibration limit is 108.01V (108.13V - 0.12V). Therefore, for bus 1F:
108.01V - 1.32V - 0.22V 106.47V.
After the dropout setpoint at the lower calibration limit is verified, the drift value (LRD) of 0.80V is determined for derivation of the lower Allowable Value. The lower Allowable Value is derived by subtracting the drift from the upper calibration limit of the dropout setpoint. The dropout setpoint at the upper calibration limit is 108.25V (108.13V + 0.12V). This lower Allowable Value (LAV) is 107.45V (108.25V - 0.80V).
Once all the values for the dropout setpoint, lower Allowable Value and the dropout calibration limits are determined, then the pickup or reset setpoint needs to be determined. Design Engineering has requested that the pickup setpoint be as small as possible. For this model of relay, a potentiometer is used to set the difference between the dropout and the pickup setpoints. The smallest difference between the two setpoints is 0.5% of the dropout setting.
Therefore, the minimum pickup setpoint is 100.5% of the dropout nominal setting of 108.13V.
This value equates to 108.68V (108.13
- 100.5%).
At this point, the same process used for determining the lower settings is used to determine the upper settings, adding the UCSA to the upper calibration limit to verify a margin of 0%
against the upper analytical limit at the relay (Vr) and adding URD to the lower calibration limit to determine an upper Allowable Value (UAV) of 109.36V.
Following this process, the calibration limits for bus 1F were determined to be:
108.01V and 108.25V (108.13V +/-0.12V) for the dropout setpoint and 108.56V and 108.80V (108.68V +/-0.12V) for the pickup or reset setpoint.
This methodology provides a margin of 0.20% setting for the dropout function and 0% setting for the pickup (reset) function.
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 5 of 23 An OE search was performed using the following keywords:
Degraded Grid Relay, Harmonic Filter, Harmonic Restraint, ABB 27N, DVR Relay and DVR The results are as follows:
Table 2 - OE Search Results OE Source Potential Project Impact: Relevance/Impact LER 92- On 3/31/92, with the reactor shutdown The setting tolerance used in the 012-00 for routine refueling and maintenance, calculation for the undervoltage (Hatch) the Electrical Maintenance Department function of the relays is assumed found the setpoints of four degraded to be equal to the worst case grid undervoltage relays (EIIS=EB) to reference accuracy of +/-0.12 VAC be below their technical specification (0.1%*120VAC). The drift limits. This condition was identified allowance used is based on plant while performing normal surveillance historical data for ABB 27N activities associated with emergency degraded voltage relays used in a busses three and four. The cause of similar application at a plant with the event is attributed to setpoint drift similar operating conditions and outside of an extremely tight tolerance calibration practices. This should band. The relays were reset to within allow for adequate tolerance their proper tolerance band. between the limiting technical specification NTSPs and AVs.
O&MR 225 During calibration of the 4160V 'D' and The relays used for this application
'E' bus undervoltage relay system, the are the Brown Boveri setpoints for three ITE model 27H recommended 27N models.
relays in 4160V bus '1E' were found out of tolerance. Plants using ITE model 27H relays in their undervoltage protection systems should check them for unacceptable setpoint drift. The supplier, Brown Boveri, advises that ITE model 27N relays should be used for this application.
SEN 272 The bus ground fault protection relay, The settings chosen for the relays 50G/A52-84, actuated and isolated provide sufficent margin power to the bus. The 50G relay betweenthe lower and upper range spuriously operated in response to the limits to avoid spurious actuations.
fault condition; but the cause, although not fully conclusive, is suspected to be high-frequency energy from the ground fault. The high-frequency current flow through the cable capacitance-to-ground reached sufficient magnitudes to actuate the 50G relay. The 50G relay on 1B-04 is a solid-state design and was set at 10 amperes, the lower end of the range (10 to 50 amps) per generic industry guidance. The companion 50G/1A52-58 relay on the other safeguards train, 1B-03, is an older style electromechanical relay and was also
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 6 of 23 OE Source Potential Project Impact: Relevance/Impact set at the low end of the 2.5 to 5 amperes range. The station replaced the 50G/A52-84 train B relay. The settings of both relays were increased to approximately midrange within the acceptable bands. The 50G/A52-84 relay setting was raised from 10 amperes to 30 amperes to reduce the potential for spurious trips. The companion 50G/1A52-58 relay setting on safeguards train 1B-03 was raised to 3 amperes. The solid state design relays are within IEEE generic guidance. No guidance was located for the older electromechanical design relays.
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 7 of 23 4.0 Functional Description The undervoltage relays monitor voltage on 4160 VAC emergency buses 1F, 1G, 2F and 2G (three relays per bus) and actuate when the voltage falls below a predetermined value and remains below this value for a specified amount of time. Actuation of any two out of three relays on the same bus results in an automatic trip of the applicable 4160 VAC preferred power supply breakers, disconnecting the undervoltage (degraded) bus from its offsite preferred power source. The degraded grid voltage and time settings are selected to avoid any nuisance tripping during normal operating conditions while ensuring that the voltage requirements of the safety-related loads are met without exceeding the maximum time delay assumed in the safety analyses.
Figure 2 - Loop Configuration 4160 VAC BUS POTENTIAL TRANSFORMER 4200/120 27 RELAY UV 27-x CONTACT CLOSES ON SUSTAINED*
UNDER VOLTAGE CONDITION
- (AFTER TIME DELAY)
TO AUXILIARY RELAYS ACTUATION LOGIC
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 8 of 23 5.0 Body of Calculation Sensor TPNS Tag #:4160V Bus 1F Relays: 27F3 (3-1), 27F3 (2-3), 27F3 (1-2) 4160V Bus 1G Relays: 27G3 (3-1), 27G3 (2-3), 27G3 (1-2) 4160V Bus 2F Relays: 27F3 (3-1), 27F3 (2-3), 27F3 (1-2) 4160V Bus 2G Relays: 27G3 (3-1), 27G3 (2-3), 27G3 (1-2)
Manufacturer: Asea Brown Boveri (ABB) Model 27N411T5375-HF PM: Once every 18 months Location of Sensor: Auxiliary Building Environmental/Seismic Conditions Normal Design Calibration Temperature 80°F 110°F 70°F Pressure N/A N/A N/A Humidity N/A N/A N/A Assumptions
- 1. Accuracy specifications provided in DI-1 for the undervoltage function are based on the specific operating temperature and control power range applicable to the relays. All accuracies are in % setting and are as follows:
Pickup and dropout settings, repeatability (RRA): +/-0.1% at constant temperature and voltage Pickup and dropout settings, repeatability (TE): +/- 0.75% over a temperature range of 0 to +55°C (32 to 131°F)
Pickup and dropout settings, repeatability (PSE): +/-0.1% over a control power range of 100 to 140 VDC (125VDC nominal)
The vendor specifies that these tolerances may be cumulative. Therefore, these variables will be considered interactive for the purposes of this calculation.
- 2. The relays are solid state devices whose accuracy is not affected by the expected normal auxiliary building pressure and humidity. Therefore, pressure effect (RPE) and humidity effect (HE) are not applicable for the undervoltage function.
RPE = HE = 0.
- 3. Based on section 2.4 of attachment 1 to DI-2, the average temperature for the auxiliary building is 80°F and the design limit of the auxiliary building room ambient temperature is 110°F. The minimum temperature expected in the rooms in which the relays are located is 60°F (Reference DI-16). Therefore, for this application the temperature range is assumed to be 60°F to 110°F.
- 4. The calibration tolerance (RCSA) for the undervoltage function trip and reset is assumed to be equal to the worst case reference accuracy of +/-0.12 VAC (0.1%*120VAC).
- 5. A Fluke 8600A (200 VAC) is assumed to be used to read the voltage input when calibrating the voltage function of the relays. Per DI-2, attachment 2 the accuracy of a Fluke 8600A is 0.2% of input + 0.015% of range. Therefore, instrument calibration accuracy (RMTE) is equal to 0.2% of setting + 0.03 VAC for the undervoltage function.
- 6. The vendor does not specify a drift value for the undervoltage function and no plant historical data is available on the ABB 27N relays. However, there are ABB 27N relays
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 9 of 23 used at the E. I. Hatch Nuclear Plant in a similar application. A drift analysis was performed on the calibration data available from these relays (Attachment A). The various factors that can contribute to variations in the drift performance between the two plants (Hatch and Farley) are compared and evaluated in the following table.
Table 3 - Evaluated Drift Factors Analyzed relays Farley Item Factor Discussion (E.I Hatch) application 1 Calibration NA NA The 27N relays are bistable Span devices.
2 Operating 50 to 105°F 60 to 110°F, The upper limit indicated for this Environment* (Reference DI-9) average application is the design limit.
temperature 80°F Based on the average (Reference temperature of the relays of 80°F, Assumption 3, DI- it is reasonable to assume that 15 & DI-16) the actual temperature in the area will not exceed 105°F. Therefore, for the purpose of this analysis the operating temperature of the analyzed relays envelops the operating temperature of the relays being used for this application and this parameter is not a factor in applying the calculated drift values to the new relays.
3 Calibration Per DI-13 & DI-14 The same or No adverse variation in calibration Practice better practices. Therefore, calibration (Assumption 16 & practice is not a factor in applying
- 17) the calculated drift values to the new relays.
4 Calibration Setpoint/reset Setpoint/reset The undervoltage setpoint/reset Check Point point (nominal) point (nominal) points of the two plants are Voltage: 109 to Voltage: 107.86 to reasonably close (within 3.4%)
111/110 to 112 108.63/108.40 to and therefore, the calibration VAC 109.18 VAC check point difference is not considered a factor in applying (Reference DI-13 (Derived in this the calculated drift values to the
& DI-14) calculation) new relays.
5 Calibration Analyzed for 18 Same (18 month N/A Interval month interval extended to 22.5 month) 6 Human See discussion See discussion The technicians performing the Performance calibrations are assumed to have commensurate skills and experience. Therefore, human performance is not a factor.
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 10 of 23 Analyzed relays Farley Item Factor Discussion (E.I Hatch) application 7 Instrument See discussion See discussion Age-dependent drift is the Age tendency for instrument drift to trend as the instrument ages. A review of the data in Attachment A does not indicate any drift trend as the relay aged. Therefore, instrument age is not a consideration for this application.
- Variations in pressure and humidity are assumed to have no effect on the relay (Assumption 2).
Based on the above evaluation it is reasonable to assume that the undervoltage function drift is equal to the drift value derived in Attachment A for a 22.5 month interval of 0.53%
setting (rounded from 0.5265% setting) with no significant bias. However, for conservatism, a drift value of 0.73% setting shall be used in this calculation.
- 7. Per DI-3, the potential transformers for buses 1F, 1G, 2F, 2G are loaded such that a 0.3% accuracy applies (PEA). Therefore, PEA = 0.3%.
- 8. The maximum voltage drop on the cables from the PTs to the DVRs is calculated in Attachment 7 of DI-4 and 8 as 0.12 V. This value is subtracted from the 120 VAC upper analytical limit (Vs) to determine the actual upper analytical limits at the relays (Vr) and added to the derived upper (reset) relay settings to determine the voltage on the primary side of the transformers (Vp). For conservatism, the voltage drop is not applied to the lower analytical limit.
- 9. The primary to secondary voltage ratio of the transformer is 35:1 (4200VAC:120VAC).
- 10. The test source used in calibrating the relays has less than 0.3% harmonic distortion.
- 11. Radiation and seismic effects (RE and SE) are assumed to be negligible (zero).
- 12. The relays are operated within the vendor specified parameters for temperature (-22 to
+158°F) (Reference DI-1); therefore, temperature effects (TE) for the undervoltage function are as specified in assumption 1.
- 13. The revised voltage analytical limits are based on plant modifications as described in DI-4 and DI-8.
- 14. The control power at the relays is assumed to be within the vendor specified parameters of 100 - 140 VDC. This is based on DI-5, which specifies that the maximum voltage of the battery chargers which supply power to the relays is 132 VDC +/-0.5% (132.66 VDC).
The minimum voltage at the relays occurs when the relays are being powered by the emergency batteries only. DI-6 and DI-7 indicate that this voltage does not fall below the lower limitation (100 VDC) of the relays. Therefore, power supply effects (PSE) for the undervoltage function are as specified in assumption 1.
- 15. The drift uncertainty is time dependent and non-linear and can be extrapolated using the square root of the sum of the squares (SRSS) method per section 6.2.7 of Reference 1.
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 11 of 23
- 16. The maintenance and test equipment (M&TE) used for the calibration of the Farley degraded voltage relays will be equivalent or better than the M&TE equipment used to calibrate the Hatch degraded grid ABB 27N alarm relays identified in Attachment A.
- 17. The calibration methodology used for the Farley degraded voltage relays will be the same methodology used to calibrate the Hatch degraded grid ABB 27N alarm relays (see assumption 6, Attachment A and section 7.5 of DI-13 & DI-14).
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 12 of 23 Buses 1F, 1G, 2F and 2G Undervoltage Function:
Table 4 - Derivation of Uncertainties (Undervoltage Function)
UNCERTAINTY PARAMETER JUSTIFICATION VALUE
(% SETTING)
RRA RRA = +/-0.10% SETTING (Assumption 1) +/-0.10 A Fluke 8600A (200 VAC) will be used to calibrate the undervoltage function of the relays (Assumption 5)
RMTE = +/-0.2% SETTING + 0.03 VAC
+/-0.2 + 3.0 _
RMTE = +/-0.2 + (0.03*100) % SETTING SETTING SETTING
= +/-(0.2 + 3.0 ) % SETTING SETTING RD RD = +/-0.73% SETTING (Assumption 6) +/-0.73 RCSA = +/-0.12 VAC (Assumption 4)
= +/-(0.12 VAC*100) * (% SETTING)
+/- 12.0 _
RCSA SETTING SETTING
= +/- ( 12.0_ ) % SETTING SETTING RTE = +/-((TE + PSE)2 + HE2 + RE2) 1/2 (Assumptions 1, 2, 11)
RTE +/-0.85
= +/-(0.75 + 0.1)2 + 02 + 02)1/2 % SETTING
= +/-0.85% SETTING RPE = 0.0 VAC (Assumption 2)
= +/-(0.0 VAC
- 100) % SETTING RPE +/-0.0 SETTING
= +/-0.0% SETTING Relay Reset Differential RSM = 0.5% SETTING (Reference DI-1) 0.5 (RSM)
Process Allowances:
Process Parameter Tag #:
4160V Bus 1F 4200/120 VAC Transformers:
PT-1, PT-2, PT-3 4160V Bus 1G 4200/120 VAC Transformers:
PT-1, PT-2, PT-3 4160V Bus 2F 4200/120 VAC Transformers:
PT-1, PT-2, PT-3 4160V Bus 2G 4200/120 VAC Transformers:
+/- 36.0 _
PEA PT-1, PT-2, PT-3 SETTING
Description:
primary element Description of PEA: transformer PEA = +/-0.3% full scale (Assumption 7)
= +/- ((0.3
- 120 VAC) * (100) _ % SETTING 100 SETTING
= +/- (36.0) % SETTING SETTING
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 13 of 23 PMA does not apply to transformers. Therefore, PMA =
PMA N/A N/A Bias:
EA The cables, transformers and relays are not exposed to a N/A harsh environment. Therefore, EA = N/A. (Reference DI-15)
Bias No bias terms exist for this loop. Therefore, Bias = N/A N/A Therefore, based on the equation derived in section 3.0:
CSA = +/- [(RCSA+RMTE)2 + (RRA)2 + (RTE)2 + (RPE)2 + (RD)2+ (PEA)2]1/2 2
CSA =+/- 12.0 + 0.2 + 3.0 + (0.10)2+ (0.85)2+ (0)2+ (0.73)2+ 36.0 2 1/2
% SETTING SETTING SETTING SETTING 2 1/2
=+/- 15.0 + 0.2 + 0.01 + 0.7225 + 0.5329 + 1296 % SETTING SETTING (SETTING)2 1/2
=+/- 225 + 6.0 + 0.04 + 0.01 + 0.7225 + 0.5329 + 1296 % SETTING 2 2 (SETTING) SETTING (SETTING) 1/2
=+/- 1521 + 6.0 + 1.3054 % SETTING (SETTING)2 SETTING The Analytical Limits for the undervoltage function of the DVRs are as follows:
Bus 1F Upper Analytical Limit (UAL) = 92.76% of 4160VAC at primary (Reference DI-4, Table 1a)
= (0.9276*4160) VAC at primary
= 3858.82 VAC at primary (Vp)
= (0.9276*4160)/35 - 0.12 VAC at relay (Assumption 8)
= 110.13 VAC at relay (Vr)
Lower Analytical Limit (LAL) = 89.57% of 4160VAC at primary (Reference DI-4, Table 1a)
= (0.8957*4160) VAC at primary
= 3726.11 VAC at primary (Vp)
= (0.8957*4160)/35 at secondary/relay (Assumption 8)
= 106.47 VAC at secondary/relay (Vs,Vr)
Bus 1G Upper Analytical Limit (UAL) = 92.53% of 4160VAC at primary (Reference DI-4, Table 1a)
= (0.9253*4160) VAC at primary
= 3849.25 VAC at primary (Vp)
= (0.9253*4160)/35 - 0.12 VAC at relay (Assumption 8)
= 109.85 VAC at relay (Vr)
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 14 of 23 Lower Analytical Limit (LAL) = 89.35% of 4160VAC at primary (Reference DI-4, Table 1a)
= (0.8935*4160) VAC at primary
= 3716.96 VAC at primary (Vp)
= (0.8935*4160)/35 at secondary/relay (Assumption 8)
= 106.20 VAC at secondary/relay (Vs,Vr)
Bus 2F Upper Analytical Limit (UAL) = 92.67% of 4160VAC at primary (Reference DI-8, Table 1a)
= (0.9267*4160) VAC at primary
= 3855.07 VAC at primary (Vp)
= (0.9267*4160)/35 - 0.12 VAC at relay (Assumption 8)
= 110.02 VAC at relay (Vr)
Lower Analytical Limit (LAL) = 89.48% of 4160VAC at primary (Reference DI-8, Table 1a)
= (0.8948*4160) VAC at primary
= 3722.37 VAC at primary (Vp)
= (0.8948*4160)/35 at secondary/relay (Assumption 8)
= 106.36 VAC at secondary/relay (Vs,Vr)
Bus 2G Upper Analytical Limit (UAL) = 93.19% of 4160VAC at primary (Reference DI-8, Table 1a)
= (0.9319*4160) VAC at primary
= 3876.70 VAC at primary (Vp)
= (0.9319*4160)/35 - 0.12 VAC at relay (Assumption 8)
= 110.64 VAC at relay (Vr)
Lower Analytical Limit (LAL) = 89.99% of 4160VAC at primary (Reference DI-8, Table 1a)
= (0.8999*4160) VAC at primary
= 3743.58 VAC at primary (Vp)
= (0.8999*4160)/35 at secondary/relay (Assumption 8)
= 106.96 VAC at secondary/relay (Vs,Vr)
The values calculated in the following tables are based on the methodology outlined in DI-2, section A.3.45 and presented as shown in DI-2, Appendix B page 52.
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 15 of 23 Table 5 - Bus 1F Calculation of Limiting Values (Undervoltage Function)
Reset Point at Upper Reset Point at Lower At Reset Point Calibration Limit Calibration Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
Upper Analytical Limit (UAL) **(Vr) 110.13 91.78 110.13 91.78 110.13 91.78 Upper Margin (UM) 0.12 0.10 0.00 0.00 0.24 0.20 Adjusted UAL (UAL-UM) 110.01 91.68 110.13 91.78 109.89 91.58 Upper Allowable Value (UAV) =
UCLL + URD 109.36 91.13 URD 0.73 0.80 0.67
[1521/SETTING2 +
UCSA 6.0/SETTING
+1.3054]1/2 1.33 1.11 1.33 1.11 1.33 1.11 UCLH (Upper Calibration Limit -
High) TS RSP = UNTSP + RCSA 108.80* 90.67 RCSA 12.0/SETTING 0.12 0.10 Upper Nominal Reset Point (UNTSP) pickup 108.68* 90.57 RCSA 12.0/SETTING 0.12 0.10 UCLL (Upper Calibration Limit -
Low) = UNTSP - RCSA 108.56* 90.47 At Setpoint (Proposed Relay Setpoint at Upper Calibration Setpoint at Lower Calibration Setting) Limit Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
LCLH (Lower Calibration Limit -
High) = LNTSP + RCSA 108.25* 90.21 RCSA 12.0/SETTING 0.12 0.10 Lower Nominal Trip Setpoint (LNTSP) dropout 108.13* 90.11 RCSA 12.0/SETTING 0.12 0.10 LCLL (Lower Calibration Limit -
Low) TS SP = LNTSP - RCSA 108.01* 90.01
[1521/SETTING2 +
LCSA 6.0/SETTING
+1.3054]1/2 1.33 1.11 1.33 1.11 1.32 1.10 LRD 0.73 0.80 0.67 Lower Allowable Value (LAV) =
setting value - LRD 107.45 89.54 Adjusted LAL (LAL + LM) 106.80 89.00 106.92 89.10 106.69 88.91 Lower Margin (LM) 0.33 0.27 0.45 0.38 0.22 0.18 Lower Analytical Limit (LAL) (Vs) 106.47 88.73 106.47 88.73 106.47 88.73
- Indicates setting value used to calculate AV, RCSA and CSA for each section outlined in the Table
- Adjusted for voltage drop of 0.12V at secondary (Assumption 8)
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 16 of 23 Bus 1F Undervoltage Function:
Based on Table 5 the limiting settings for the undervoltage function for Bus 1F are as follows:
Upper Allowable Value (reset point) = 109.36 VAC (91.13% 120VAC) increasing at relay (Vr)
= (109.36 VAC + 0.12)
- 35 = 3831.80 VAC increasing at primary (Assumption 8) (Vp)
= (3831.80/4160)
- 100% = 92.11% 4160VAC increasing at primary Nominal Reset point = 108.68 VAC (90.57% 120VAC) increasing at relay (Vr)
= (108.68 VAC + 0.12)
- 35 = 3808.00 VAC increasing at primary (Assumption 8) (Vp)
= (3808.00/4160)
- 100% = 91.54% 4160VAC increasing at primary Nominal Setpoint = 108.13 VAC (90.11% 120VAC) decreasing at secondary (Vs, Vr)
= 108.13 VAC
- 35 = 3784.55 VAC decreasing at primary (Vp)
= (3784.55/4160)
- 100% = 90.97% 4160VAC decreasing at primary Lower Allowable Value (setpoint) = 107.45 VAC (89.54% 120VAC) decreasing at secondary (Vs, Vr)
= 107.45 VAC
- 35 = 3760.75 VAC decreasing at primary (Vp)
= (3760.75/4160)
- 100% = 90.40% 4160VAC decreasing at primary This allows for a minimum margin of 0.22 VAC (0.20% of the lower calibration limit of 108.01 VAC).
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 17 of 23 Table 6 - Bus 1G Calculation of Limiting Values (Undervoltage Function)
Reset Point at Upper Reset Point at Lower At Reset Point Calibration Limit Calibration Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
Upper Analytical Limit (UAL) ** (Vr) 109.85 91.54 109.85 91.54 109.85 91.54 Upper Margin (UM) 0.12 0.10 0.00 0.00 0.24 0.20 Adjusted UAL (UAL-UM) 109.73 91.44 109.85 91.54 109.61 91.34 Upper Allowable Value (UAV) =
UCLL + URD 109.08 90.90 URD 0.73 0.80 0.67
[1521/SETTING2 +
UCSA 6.0/SETTING
+1.3054]1/2 1.33 1.11 1.33 1.11 1.33 1.11 UCLH (Upper Calibration Limit -
High) TS RSP = UNTSP + RCSA 108.52* 90.43 RCSA 12.0/SETTING 0.12 0.10 Upper Nominal Reset Point (UNTSP) pickup 108.40* 90.33 RCSA 12.0/SETTING 0.12 0.10 UCLL (Upper Calibration Limit -
Low) = UNTSP - RCSA 108.28* 90.23 At Setpoint (Proposed Relay Setpoint at Upper Calibration Setpoint at Lower Calibration Setting) Limit Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
LCLH (Lower Calibration Limit -
High) = LNTSP + RCSA 107.98* 89.98 RCSA 12.0/SETTING 0.12 0.10 Lower Nominal Trip Setpoint (LNTSP) dropout 107.86* 89.88 RCSA 12.0/SETTING 0.12 0.10 LCLL (Lower Calibration Limit -
Low) TS SP = LNTSP - RCSA 107.74* 89.78
[1521/SETTING2 +
LCSA 6.0/SETTING
+1.3054]1/2 1.32 1.10 1.32 1.10 1.32 1.10 LRD 0.73 0.79 0.66 Lower Allowable Value (LAV) =
setting value - LRD 107.19 89.33 Adjusted LAL (LAL + LM) 106.54 88.78 106.66 88.88 106.42 88.68 Lower Margin (LM) 0.34 0.28 0.46 0.38 0.22 0.18 Lower Analytical Limit (LAL) (Vs) 106.20 88.50 106.20 88.50 106.20 88.50
- Indicates setting value used to calculate AV, RCSA and CSA for each section outlined in the Table
- Adjusted for voltage drop of 0.12V at secondary (Assumption 8)
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 18 of 23 Bus 1G Undervoltage Function:
Based on Table 6 the limiting settings for the undervoltage function for Bus 1G are as follows:
Upper Allowable Value (reset point) = 109.08 VAC (90.90% 120VAC) increasing at relay (Vr)
= (109.08 VAC + 0.12)
- 35 = 3822.00 VAC increasing at primary (Assumption 8) (Vp)
= (3822.00/4160)
- 100% = 91.88% 4160VAC increasing at primary Reset point = 108.40 VAC (90.33% 120VAC) increasing at relay (Vr)
= (108.40 VAC + 0.12)
- 35 = 3798.20 VAC increasing at primary (Assumption 8) (Vp)
= (3798.20/4160)
- 100% = 91.30% 4160VAC increasing at primary Setpoint = 107.86 VAC ((89.88% 120VAC) decreasing at secondary (Vs, Vr)
= 107.86 VAC
- 35 = 3775.10 VAC decreasing at primary (Vp)
= (3775.10/4160)
- 100% = 90.75% 4160VAC decreasing at primary Lower Allowable Value (setpoint) = 107.19 VAC (89.33% 120VAC) decreasing at secondary (Vs, Vr)
= 107.19 VAC
- 35 = 3751.65 VAC decreasing at primary (Vp)
= (3751.65/4160)
- 100% = 90.18% 4160VAC decreasing at primary This allows for a minimum margin of 0.22 VAC (0.20% of the lower calibration limit of 107.74 VAC).
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 19 of 23 Table 7- Bus 2F Calculation of Limiting Values (Undervoltage Function)
Reset Point at Upper Reset Point at Lower At Reset Point Calibration Limit Calibration Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
Upper Analytical Limit (UAL) ** (Vr) 110.02 91.68 110.02 91.68 110.02 91.68 Upper Margin (UM) 0.12 0.10 0.00 0.00 0.24 0.20 Adjusted UAL (UAL-UM) 109.90 91.58 110.02 91.68 109.78 91.48 Upper Allowable Value (UAV) =
UCLL + URD 109.25 91.04 URD 0.73 0.80 0.67
[1521/SETTING2 +
UCSA 6.0/SETTING
+1.3054]1/2 1.33 1.11 1.33 1.11 1.33 1.11 UCLH (Upper Calibration Limit -
High) TS RSP = UNTSP + RCSA 108.69* 90.58 RCSA 12.0/SETTING 0.12 0.10 Upper Nominal Reset Point (UNTSP) pickup 108.57* 90.48 RCSA 12.0/SETTING 0.12 0.10 UCLL (Upper Calibration Limit -
Low) = UNTSP - RCSA 108.45* 90.38 At Setpoint (Proposed Relay Setpoint at Upper Calibration Setpoint at Lower Calibration Setting) Limit Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
LCLH (Lower Calibration Limit -
High) = LNTSP + RCSA 108.14* 90.12 RCSA 12.0/SETTING 0.12 0.10 Lower Nominal Trip Setpoint (LNTSP) dropout 108.02* 90.02 RCSA 12.0/SETTING 0.12 0.10 LCLL (Lower Calibration Limit -
Low) TS SP = LNTSP - RCSA 107.90* 89.92
[1521/SETTING2 +
LCSA 6.0/SETTING
+1.3054]1/2 1.32 1.10 1.33 1.11 1.32 1.10 LRD 0.73 0.79 0.66 0.79 0.66 0.79 0.66 Lower Allowable Value (LAV) =
setting value - LRD 107.35 89.46 Adjusted LAL (LAL + LM) 106.70 88.92 106.81 89.01 106.58 88.82 Lower Margin (LM) 0.34 0.28 0.45 0.38 0.22 0.18 Lower Analytical Limit (LAL) (Vs) 106.36 88.63 106.36 88.63 106.36 88.63
- Indicates setting value used to calculate AV, RCSA and CSA for each section outlined in the Table
- Adjusted for voltage drop of 0.12V at secondary (Assumption 8)
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 20 of 23 Bus 2F Undervoltage Function:
Upper Allowable Value (reset point) = 109.25 VAC (91.04% 120VAC) increasing at relay (Vr)
= (109.25 VAC + 0.12)
- 35 = 3827.95 VAC increasing at primary (Assumption 8) (Vp)
= (3827.95/4160)
- 100% = 92.02% 4160VAC increasing at primary Reset point = 108.57 VAC (90.48% 120VAC) increasing at relay (Vr)
= (108.57 VAC+ 0.12)
- 35 = 3804.15 VAC increasing at primary (Assumption 8) (Vp)
= (3804.15/4160)
- 100% = 91.45% 4160VAC increasing at primary Setpoint = 108.02 VAC (90.02% 120VAC) decreasing at secondary (Vs, Vr)
= 108.02 VAC
- 35 = 3780.70 VAC decreasing at primary (Vp)
= (3780.70/4160)
- 100% = 90.88% 4160VAC decreasing at primary Lower Allowable Value (setpoint) = 107.35 VAC (89.46% 120VAC) decreasing at secondary (Vs, Vr)
= 107.35 VAC
- 35 = 3757.25 VAC decreasing at primary (Vp)
= (3757.25/4160)
- 100% = 90.32% 4160VAC decreasing at primary This allows for a minimum margin of 0.22 VAC (0.20% of the lower calibration limit of 107.90 VAC).
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 21 of 23 Table 8 - Bus 2G Calculation of Limiting Values (Undervoltage Function)
Reset Point at Upper Reset Point at Lower At Reset Point Calibration Limit Calibration Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
Upper Analytical Limit (UAL) ** (Vr) 110.64 92.20 110.64 92.20 110.64 92.20 Upper Margin (UM) 0.12 0.10 0.00 0.00 0.24 0.20 Adjusted UAL (UAL-UM) 110.52 92.10 110.64 92.20 110.40 92.00 Upper Allowable Value (UAV) =
UCLL + URD 109.86 91.55 URD 0.73 0.80 0.67
[1521/SETTING2 +
UCSA 6.0/SETTING
+1.3054]1/2 1.34 1.12 1.34 1.12 1.34 1.12 UCLH (Upper Calibration Limit -
High) TS RSP = UNTSP + RCSA 109.30* 91.08 RCSA 12.0/SETTING 0.12 0.10 Upper Nominal Reset Point (UNTSP) pickup 109.18* 90.98 RCSA 12.0/SETTING 0.12 0.10 UCLL (Upper Calibration Limit -
Low) = UNTSP - RCSA 109.06* 90.88 At Setpoint (Proposed Relay Setpoint at Upper Calibration Setpoint at Lower Calibration Setting) Limit Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
LCLH (Lower Calibration Limit -
High) = LNTSP + RCSA 108.75* 90.63 RCSA 12.0/SETTING 0.12 0.10 Lower Nominal Trip Setpoint (LNTSP) dropout 108.63* 90.53 RCSA 12.0/SETTING 0.12 0.10 LCLL (Lower Calibration Limit -
Low) TS SP = LNTSP - RCSA 108.51* 90.43
[1521/SETTING2 +
LCSA 6.0/SETTING
+1.3054]1/2 1.33 1.11 1.33 1.11 1.33 1.11 LRD 0.73 0.80 0.67 0.80 0.67 Lower Allowable Value (LAV) =
setting value - LRD 107.95 89.96 Adjusted LAL (LAL + LM) 107.30 89.42 107.42 89.52 107.18 89.32 Lower Margin (LM) 0.34 0.28 0.46 0.38 0.22 0.18 Lower Analytical Limit (LAL) (Vs) 106.96 89.13 106.96 89.13 106.96 89.13
- Indicates setting value used to calculate AV, RCSA and CSA for each section outlined in the Table
- Adjusted for voltage drop of 0.12V at secondary (Assumption 8)
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 22 of 23 Bus 2G Undervoltage Function:
Upper Allowable Value (reset point) = 109.86 VAC (91.55% 120VAC) increasing at relay (Vr)
= 109.86 VAC + 0.12)
- 35 = 3849.30 VAC increasing at primary (Assumption 8) (Vp)
= (3849.30/4160)
- 100% = 92.53% 4160VAC increasing at primary Reset point = 109.18 VAC (90.98% 120VAC) increasing at relay (Vr)
= 109.18 VAC + 0.12)
- 35 = 3825.50 VAC increasing at primary (Assumption 8) (Vp)
= (3825.50/4160)
- 100% = 91.96% 4160VAC increasing at primary Setpoint = 108.63 VAC (90.53% 120VAC) decreasing at secondary (Vs, Vr)
= 108.63 VAC
- 35 = 3802.05 VAC decreasing at primary (Vp)
= (3802.05/4160)
- 100% = 91.40% 4160VAC decreasing at primary Lower Allowable Value (setpoint) = 107.95 VAC (89.96% 120VAC) decreasing at secondary (Vs, Vr)
= 107.95 VAC
- 35 = 3778.25 VAC decreasing at primary (Vp)
= (3778.25/4160)
- 100% = 90.82% 4160VAC decreasing at primary This allows for a minimum margin of 0.22 VAC (0.20% of the lower calibration limit of 108.51 VAC)
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 23 of 23 Design Inputs (DI):
(1) IB 7.4.1.7-7, ABB Instructions Single Phase Voltage Relays (Attachment B)
(2) NMP-ES-033-004, Version 6.0, Setpoint Control Program Farley Setpoint Uncertainty Methodology and Scaling Instructions (3) Calculation SE-92-2204-2-PE, Version 3.0, Analysis of P.T. Accuracy for 4kV Buses 1F, 1G, 2F and 2G (4) Calculation SE-SNC529029-001, Version 1.0, Unit 1 Minimum Expected Voltage Study (5) Calculation E-035.01.C, Version 2.0, Setting of Protective Relays for FNP Unit 1 125VDC Auxiliary Power System (6) Calculation E-095, Version 13.0, Auxiliary Building Battery Capacity and Voltage Evaluation (7) Calculation E-098, Version 5.0, Criteria For Circuit Lengths For 125V DC Control Circuits (8) Calculation SE-SNC529029-002, Version 1.0, Unit 2 Minimum Expected Voltage Study (9) Edwin I. Hatch Nuclear Plant Unit No 1 & 2 Document H12619, Version 12.0, Architectural - Generator Building Heating & Ventilating General Arrangement &
Parts Numbers (10) EPRI TR-103335, Guidelines for Instrument Calibration Extension / Reduction -
Revision 1 (11) NUREG-1475, Revision 1, Applying Statistics (12) ANSI N15.15-1974, Assessment Of The Assumption Of Normality (Employing Individual Observed Values)
(13) Southern Nuclear Plant E. I. Hatch Surveillance Procedure, 57SV-S32-002-1, Version 11.0, Emergency Buses 1E, 1F, and 1G Undervoltage Relay Instrument FT&C (14) Southern Nuclear Plant E. I. Hatch Surveillance Procedure, 57SV-S32-002-2, Version 13.2, Emergency Buses 2E, 2F, and 2G Undervoltage Relay FT&C (15) FNP FSAR Section 3.11.2.2, Equipment Outside Containment, Rev 21, dated 5/08 (16) FNP FSAR Section 9.4.2.1.1, Nonradioactive Area Heating and Ventilating System, Rev 24, dated 10/12
References:
(1) ISA-RP67.04.02-2000, Recommended Practice, Methodologies for the Determination of Setpoints for Nuclear Safety-Related Instrumentation
Charles A. Pierce Southern Nuclear Regulatory Affairs Director Operating Company, Inc.
40 Inverness Center Parkway Post Office Box 1295 Birmingham, AL 35242 Tel 205 .992.7872 SOUTHERN << \
Fax 205.992.7601 NUCLEAR A SOUTHERN COMPANY January 12, 2016 Docket Nos.: 50-348 NL-16-0007 50-364 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555-0001 Joseph M. Farley Nuclear Plant, Units 1 and 2 Technical Specification 3.3.5 Loss of Power Diesel Generator Start Instrumentation Supplement to License Amendment Request Ladies and Gentlemen:
In accordance with the requirements of 10 CFR 50.90, Southern Nuclear Operating Company (SNC) submitted a request via a letter dated November 20, 2015 (NL-15-0722}, for an amendment to the Joseph M. Farley Nuclear Plant (FNP) Units 1 and 2 Technical Specifications (TS}. That amendment request proposes to revise TS 3.3.5, "Loss of Power Diesel Generator Start Instrumentation," to enable compliance with a license condition for each unit which requires elimination of manual actions as part of the FNP degraded voltage protection scheme.
Included in the proposed changes toTS 3.3.5 are new voltage and delay time Allowable Values for the 4.16 kV Emergency Bus Degraded Grid Voltage Actuation function. As a supplement to the November 20, 20151icense amendment request, enclosed are copies of the calculations which support these new Allowable Values.
Enclosures 1 and 2 are the calculations which established the delay times for the degraded grid voltage relays for Units 1 and 2, respectively; Enclosure 3 is the calculation which established the relay actuation voltages for both units.
Provided are the bodies of the calculations, which detail the methodology employed and the results obtained. The attachments to the calculations have been omitted since their inclusion would add several hundred pages of material only peripheral to the requested changes (such as modeling software output reports, relay manufacturer's specifications, etc.).
In accordance with the requirements of § 50.91, a copy of this supplement to SNC's November 20, 2015 license amendment request is provided to the designated Alabama official.
U.S. Nuclear Regulatory Commiss ion NL-16-00 07 Page 2 This letter contains no NRC commitments. If you have any questions, please contact Ken McElroy at (205) 992-7369.
Mr. Pierce states he is Regulato ry Affairs Director of Southern Nuclear Operating Company, is authorized to execute this oath on behalf of Southern Nuclear Operating Company and to the best of his knowledge and belief, the facts set forth in this letter are true.
Res2~7J;;d, C. R. Pierce Regulatory Affairs Director
, 2016.
My commission expires: /6- !'-J.ot1 CRP/DW D/cg
Enclosures:
- 1. FNP Unit 1 Calculation SE-SNC529029-001 - Minimum Expected Voltage Study
- 3. FNP Units 1 & 2 Calculation SJ-SNC529029-001 -Determi nation of Setpoints cc: Southern Nuclear Operating Company Mr. S. E. Kuczynski, Chairman, Presiden t & CEO Mr. D. G. Bast, Executive Vice Presiden t & Chief Nuclear Officer Ms. C. A. Gayheart, Vice Presiden t- Farley Mr. D. R. Madison, Vice Presiden t- Fleet Operation s Mr. M. D. Meier, Vice Presiden t- Regulato ry Affairs Mr. B. J. Adams, Vice Presiden t- Engineering Ms. B. L. Taylor, Regulatory Affairs Manage r- Farley RType: CFA04.0 54 U.S. Nuclear Regulatory Commiss ion Mr. L. D. Wert, Regional Administr ator Mr. S. A. Williams, NRR Project Manager - Farley Mr. P. K. Niebaum, Senior Resident Inspecto r- Farley Alabama Departme nt of Public Health Dr. D. E. Williamson, State Health Officer
Joseph M. Farley Nuclear Plant, Units 1 and 2 Technical Specification 3.3.5 Loss of Power Diesel Generator Start Instrumentation Supplement to License Amendment Request Enclosure 1 FNP Unit 1 Calculation SE-SNC529029-001 Minimum Expected Voltage Study (Attachments to calculation not included)
SOUTHERN COMPANY A. Southern Nuclear Design Calculation E*nu"' Snw Yoar W&riJ" Calculation Number:
SE-SNC529029-001 Plant: 1 Unit: I Discipline:
J.M. Farley Nuclear Plant
Title:
Unit 1 Minimum Expected Voltage Study
~1 02 01&2 I
Subject:
Electrical AC System Analysis Purpose I Objective:
Determine safe operating limits of Unit 1 under degraded grid conditions System or Equipment Tag Numbers:
R01,R11,R15,R16,R17 Contents Topic Page Attachments #of (Computer Printouts, Technical Papers, Pages Sketches, Correspondence)
Version History 1 1. Summary of Steady-State and Starting 9
Design Inputs 1 Voltages at Minimum Required Voltage References 1 2. ETAP Output Reports - NORMAL Load Flow 93 Purpose of Calculation 2 3. ETAP Output Re_Qorts- LOCA Load Flow 102 Summary of Conclusions 2 4. ETAP Output Reports- Motor Starting 44 Methodology 4 5. Safety Injection Transient Plots 1 Assumptions 5 6. Thermal Overload Trip Time Tables 2 Acceptance Criteria 6 7. AC Voltage DroQ_ from PT to DVR 1 Body of Calculation 6 Total# of Pages including 264 cover sheet & Attachments:
CJ Version Record Versio Originator Reviewer Approval1 Approval2 n Description Printed Name Printed Name Printed Name Printed Name No. Initial/ Date lnltlal/Dal8 Initial/ Date Initial/Date Kaleb Drew Matt Lane i-f"~"' Mite 1..7 1.0 Issued per RER SNC529029, v1.0
!(\)
L{ /30/r) ft\(..
l.(f1o(l 'i
~~r
~ t;fr~ lrJ~tll c,-u.-1 s i/
Notes: An OE search has been performed and the results are documented in the Methodology Section.
NMP-ES-039- F01 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 1 of 11 Version History:
Version 1.0: Initial version issued for RER SNC529029.
Design Inputs:
- 1. SE-94-0470-001, Ver. 7.0, Unit 1 As-Built Load Study: Primary calculation input; source of ETAP model and methodology used for case study runs.
- 2. SE-94-0470-004, Ver. 4.0, Unit 1 Load Study Summary: LOCA starting and steady-state requirements tables modified for use as Attachment 1 of this calculation.
- 3. SJ-SNC529029-001, Ver. 1.0, Determination Of Setpoints, Reset Points, And Loop Uncertainties For 4160V Safety-Related Degraded Voltage Relay (DVR) Loops (Buses 1F, 2F, 1G And 2G)
References:
- 1. GDC 17, General Design Criteria for Nuclear Power Plants 17
- 2. IEEE Standard 399-1997, IEEE Recommended Practice for Industrial and Commercial Power Systems Analysis
- 3. NRC Regulatory Issue Summary 2011-12, Revision 1, Adequacy of Station Electric Distribution System Voltages: Guidance for degraded grid analysis acceptance criteria and methodology
- 4. Farley Nuclear Plant Units 1 & 2 Tech Spec Bases, Rev. 65
- 5. Farley Nuclear Plant Unit 1 Tech Spec, Amendment 195
- 6. Farley Nuclear Plant Units 1 & 2 FSAR, Rev. 26, Feb. 2015
- 7. SM-90-1653-002, Ver. 23.0, Reduced Voltage Torque/Thrust Capability for Gate &
Globe Valves in the FNP MOV Program
- 8. SM-90-1653-009, Ver. 8.0, Reduced Voltage Torque Capability for Butterfly Valves in the FNP MOV Program
- 9. SM-1053039201-001, Ver. 1.0, Develop Design Basis Calculations for the Penetration Room Filter Dampers
- 10. DOEJ-FRSNC52029-M001, Ver. 1.0, Evaluation of Reduced Voltage Requirements for Motor Operated Valves for use in the Degraded Voltage Protection Plan
- 11. E-035.01.A, Ver. 6.0, Setting of Protective Relays for 4.16kV Auxiliary Power System
- 12. SE-90-1845-2-PE, Ver. 8.0, Large, Small, and SBO Diesel Dynamic Study
- 13. SE-91-1976-1, Ver. 6.0, Motor Starter Control Circuit Study
- 14. SE-91-1925-14-PE, Ver. 1.0, MOV3232A,B,C: Terminal Voltage at End of Stroke
- 15. SE-99-9472-001, Ver. 1.0, Stability Review for LOSP/DGG Relay Operation
- 16. SE-94-0-0378-001, Ver. 5.0, MOV Combination Starter Component Sizes and Settings
- 17. SE-99-0-2010-001, Ver. 0.0, Verification Package for Computer Software Used to Calculate MOV Thermal Overload Heater Sizes
- 18. SE-90-1714-12, Ver. 4.0, Overload Heater Sizing and Resistance
- 20. 1995 SER, February 23, 1995, Safety Evaluation for Degraded Grid Voltage Relay Set Points
- 21. IB 7.4.1.7-7, Issue E, ABB Instructions Single Phase Voltage Relays
- 22. GEH-1768G, GE Instructions: Undervoltage Relays
- 23. MC-F-06-0143, Ver. 1.0 NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 2 of 11
- 24. MC-F-07-0014, Ver. 1.0
- 25. MC-F-07-0050, Ver. 2.0
- 26. MC-F-07-0110, Ver. 1.0
- 27. MC-F-07-0116, Ver. 1.0
- 28. MC-F-08-0017, Ver. 3.0
- 29. MC-F-08-0026, Ver. 1.0
- 30. MC-F-08-0076, Ver. 1.0
- 31. MC-F-08-0083, Ver. 1.0
- 32. MC-F-08-0091, Ver. 1.0
- 33. MC-F-08-0162, Ver. 1.0
- 34. MC-F-08-0194, Ver. 1.0
- 35. MC-F-10-0003, Ver. 1.0
- 36. MC-F-10-0005, Ver. 1.0
- 37. MC-F-10-0037, Ver. 1.0
- 38. MC-F-10-0094, Ver. 1.0
- 39. MC-F-10-0127, Ver. 1.0
- 40. MC-F-11-0022, Ver. 1.0
- 41. MC-F-11-0077, Ver. 1.0
- 42. MC-F-11-0090, Ver. 1.0
- 43. MC-F-12-0002, Ver. 1.0
- 44. MC-F-12-0031, Ver. 1.0
- 45. MC-F-12-0071, Ver. 3.0
- 46. MC-F-12-0086, Ver. 2.0
- 47. MC-F-13-0087, Ver. 1.0
- 48. MC-F-14-0009, Ver. 1.0
- 49. MC-F-14-0029, Ver. 1.0
- 50. MC-F-15-0051, Ver. 1.0
- 51. CCN-F-11-0003, Ver. 3.0 Purpose of Calculation:
The purpose of this calculation is to determine the operating range of Farley Nuclear Plant Unit 1 under degraded voltage conditions at the 230kV grid to meet the requirements of the safety-related loads using the guidance in Regulatory Issue Summary RIS 2011-12, Revision 1 (Reference 3). This operating range is used by other calculations to determine Degraded Voltage Relay (DVR) settings to automatically transfer safety-related loads from an unacceptable offsite power source to an onsite power source.
Summary of
Conclusions:
- 1. The minimum voltage that meets the steady-state requirements for all safety-related loads during the Normal and LOCA loading cases for Farley Unit 1 is determined, and is documented in Table 1a as the Minimum Required Voltage (MRV). Refer to Attachments 2 and 3 for ETAP output reports.
- 2. The required starting voltage at the safety-related motors and MOVs is satisfied for the motor starting cases established in calculation SE-94-0470-004 (Design Input 2). Refer to Attachment 4 for ETAP output reports.
NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 3 of 11
- 3. Some of the safety-related MCCs have voltages below the minimum level required for motor control circuits during the safety injection group motor start; however, per calculation SE-91-1976-1 (Reference 13), these MCCs are acceptable because with the 4kV buses at the MRV, they have the minimum required relay pickup voltage to energize upon an SI signal prior to the motor starting transient. Additionally, load voltages remain above the relay drop-out voltage. See Attachment 1 for motor starting bus voltages.
- 4. The MRV, shown in Table 1a, is lower than the DVR Lower Analytical Limit (LAL). This LAL is selected to provide margin below the DVR setpoint uncertainty range determined in Design Input 3 and above the MRV. Thus the dropout voltage of each DVR will be set such that the minimum tolerance is above the MRV for the 4160V buses 1F and 1G.
- 5. The Minimum Expected Voltage (MEV), shown in Table 1a, is higher than the DVR Upper Analytical Limit (UAL). This UAL is selected to provide margin above the DVR setpoint uncertainty range determined in Design Input 3 and below the MEV. Thus the reset voltage of each DVR will be set such that the maximum tolerance is below the MEV for the 4160V buses 1F and 1G.
- 6. The total available electrical margin available is 1.20% and 1.48% for 4160V buses 1F and 1G, respectively, per the results in Table 1a.
- 7. The DVR time delay should be set, with tolerances, so that the time is not less than the Safety Injection (SI) Transient Time, and not greater than the minimum thermal overload (TOL) relay trip time, as shown in Table 1b. It is the recommendation of this calculation to set the DVR time delay at 9.0 seconds to keep the safety-related loads on the grid as long as possible while also preventing safety-related motors from tripping due to extended overload conditions. Safety Injection Transient plots are included in Attachment 5, and TOL trip times for SI motors when below the MSV are listed in Attachment 6.
- 9. The dropout voltage of each LOSP Relay (78.25% per Reference 11) is below the Minimum Starting Voltage (MSV) shown in Table 1a for the 4160V buses 1F and 1G, which occurs immediately after a LOCA group motor start, so there is no expected interaction between the new DVR and the existing LOSP Relay.
Table 1a. Summary of Unit 1 Degraded Voltage Relay Operating Range Results.
4.16kV Bus 4.16kV Bus DVR Margin 4.16kV 4.16kV MEV DVR UAL MRV DVR LAL (MEV-MRV)
Bus Bus MSV (Attach. 2) (Attach. 1) - (UAL-LAL) 1F 93.31% 92.76% 88.92% 89.57% 81.93% 1.20%
1G 93.26% 92.53% 88.60% 89.35% 81.19% 1.48%
Table 1b. Summary of Unit 1 DVR Timing Analysis.
4.16kV SI Transient Start Time TOL Trip Time DVR Trip DVR Time Delay Bus (Attach. 5) (Attach. 6) Setpoint Allowable Value*
1F 6.5 seconds 11.5 seconds 9.0 seconds 11.4 seconds 1G
- Tech. Spec. DVR Time Setting Requirement NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 4 of 11 Methodology:
The computer model of Farley Unit 1, FNP1V07, was developed with ETAP Version 12.6.0N software package for calculation SE-94-0470-001 (Design Input 1). This calculation uses ETAP software to perform analysis of the auxiliary system including load flow, motor starting, and transient studies. Refer to the ETAP User Guide 12.6 for additional information regarding the ETAP program.
Before the ETAP model was used for this study, outstanding modification calculations (MCs) against base calculation (BC) SE-94-0470-001 (Design Input 1) were merged into the base revision in order of MC approval dates. See Table 2 in the calculation body for a detailed list of merged MCs. The ETAP model was then used to determine several values at the 4kV buses 1F and 1G: the Minimum Expected Voltage, the Minimum Required Voltage, the Minimum Starting Voltage, and the Safety Injection (SI) Transient Time. The methodology for each is described below.
- 1. Minimum Expected Voltage (MEV): The MEV is calculated as the 4kV bus voltage during LOCA steady-state with a 230kV switchyard voltage of 101.0%. In the Farley Unit 1 ETAP model FNP1V07, this is the Load Flow Study Case 1.4.
- 2. Minimum Required Voltage (MRV): The MRV is the maximum requirement of the following three calculations.
- a. Using maximum expected non-accident bus loading, determine minimum acceptable steady-state voltage for normal operation of Class 1E loads. This was performed using ETAP load flow study cases 1.3F and 1.3G.
- b. Using maximum expected accident loading, determine the minimum pre-start voltage that provides acceptable Class 1E motor starting (e.g. during LOCA group motor starting). This was performed using ETAP load flow study cases 1.4F and 1.4G.
- c. Using maximum expected accident loading, determine the minimum steady-state voltage that provides acceptable Class 1E motor operation and starting for individual motors. This was performed using ETAP motor starting study cases 4F MOV Start, 4G MOV Start, 5F LOCA Start, 5G LOCA Start, 7F LOCA ST A, and 7G LOCA ST A.
- 3. Minimum Starting Voltage (MSV): The MSV is calculated as the lowest voltage at the 4kV bus during a safety injection transient (ETAP motor starting study cases 5F LOCA Start and 5G LOCA Start) with the pre-start voltage at the MRV.
- 4. Safety Injection Transient Time: The SI Transient Time is calculated as the minimum time for the SI group motors to start and reach steady-state with the 4kV buses at the MRV. The ETAP Transient Study Case used to analyze the SI group start is developed as a part of this calculation.
NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 5 of 11 MEV MRV SI Transient Time MSV Figure 1. Example SI transient showing location of MEV, MRV, MSV, and SI Transient Time.
The OE search was performed using the following keywords:
- Degraded Grid Relay Date OE Problem Relevance / Action /
Source Impact Resolution 11/19/2009 INPO OE30473: Potential Inaccurate No motors Only applies to Induction Motor Models in ETAP- modeled at older version of Davis-Besse Unit 1: greater than ETAP. No action The cumulative load increases due 100% loading. is required.
to induction machine modeling techniques may result in non-conservative AC Power System Analyses. For motors operating at greater than 100 percent, allowing efficiency at 100 percent motor load to adjust results in a non-conservative estimate (under prediction) of EDG loading due to the ETAP extrapolation of motor efficiency beyond 100 percent loading.
Assumptions:
- 1. A minimum expected grid voltage of 101.0% at the 230kV Reference Bus is assumed and utilized in the ETAP model based on contingency studies defined by the FSAR (Reference 6).
- 2. Loads listed in Attachment 1 with steady-state voltages that do not have motor starting criteria are assumed to be able to endure a transient motor starting situation.
- 3. Low motor starting voltage for the 3232 MOVs on 600V MCC 1V can be considered acceptable during block starting since the MOVs start with no load. Per SCS Calculation SE-91-1925-14-PE (Reference 14), the maximum load occurs at the end of the close of the stroke when the motors are already running.
NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 6 of 11
- 4. A constant grid impedance of 0.87+j1.125 percent of 100MVA base is assumed and utilized in the ETAP model per calculation SE-94-0470-001, Attachment C (Design Input 1).
- 5. ABB 27N calibration limits are determined to be +/-0.5 seconds from the Plant Hatch Surveillance Procedure for degraded voltage alarm relays 57SV-S32-002-1, Emergency Buses 1E, 1F, and 1G Undervoltage Relay Instrument FT&C, Attachment 3.
Acceptance Criteria:
- 1. The required steady-state voltages at the motor terminals are established in calculation SE-94-0470-004 (Design Input 2). Non-1E motors/loads are allowed to be below 90%
rated voltage, since they are not required to mitigate a design basis event.
- 2. The required starting voltages at the safety-related motors are established in calculation SE-94-0470-004 (Design Input 2). All safety-related motors must be capable of starting at the corresponding MRV.
- 3. The required MOV starting voltages were established in mechanical torque calculations SM-90-1653-002 (Reference 7), SM-90-1653-009 (Reference 8), and SM-1053039201-001 (Reference 9), as listed in SE-94-0470-004 (Design Input 2). These starting requirements have been updated by DOEJ-FRSNC529029-M001 (Reference 10). All safety-related MOVs must be capable of starting at the corresponding MRV.
- 4. With the 4kV bus pre-start voltage at the MRV, the SI transient time should be less than the minimum TOL trip time to prevent safety-related equipment from stalling or tripping on overcurrent during a degraded voltage condition.
- 5. The MRV must be lower than the LAL, and the MEV must be higher than the UAL. The Analytical Limits must be selected to provide margin above and below the setpoint uncertainty range determined in Design Input 3.
Body of Calculation:
ETAP was used to simulate normal and accident conditions with a concurrent degraded grid condition. Outstanding MCs and CCNs (References 23-50) against SE-94-0470-001 (Design Input 1) were merged into the ETAP base revision of Farley Unit 1 model FNP1V07 in accordance with Table 2 before any case studies were analyzed. The methodology used in Design Input 1 was followed to set up the ETAP study cases. The 230kV source voltage was modified to obtain the desired voltage at the 4kV bus being studied for each case.
Table 2. List of Outstanding MCs Merged into ETAP Model Base Revision.
Approval MC Number Merged Notes Date MC-F-06-0143 v1.0 9/28/2006 Yes MC-F-07-0014 v1.0 2/7/2007 No Non-conservative MC-F-07-0110 v1.0 12/13/2007 Yes MC-F-07-0116 v1.0 12/13/2007 Yes MC-F-08-0076 v1.0 6/6/2008 Yes MC-F-08-0083 v1.0 7/11/2008 Yes MC-F-08-0091 v1.0 9/15/2008 Yes MC-F-08-0162 v1.0 11/24/2008 Yes NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 7 of 11 MC-F-08-0194 v1.0 12/19/2008 No Non-conservative MC-F-08-0017 v3.0 5/22/2009 Yes MC-F-10-0003 v1.0 2/3/2010 Yes MC-F-10-0037 v1.0 2/10/2010 Yes MC-F-10-0005 v1.0 2/11/2010 Yes MC-F-10-0094 v1.0 6/11/2010 Yes MC-F-10-0127 v1.0 12/7/2010 Yes MC-F-08-0026 v1.0 12/20/2010 Yes MC-F-11-0022 v1.0 6/28/2011 Yes MC-F-11-0090 v1.0 11/9/2011 Yes MC-F-12-0002 v1.0 3/12/2012 Yes CCN-F-11-0003 v3.0 8/2/2012 Yes MC-F-12-0031 v1.0 10/8/2012 Yes MC-F-12-0086 v2.0 4/11/2013 Yes MC-F-11-0077 v1.0 4/18/2013 Yes MC-F-12-0071 v3.0 8/1/2013 Yes MC-F-14-0029 v1.0 5/5/2014 No Non-conservative MC-F-13-0087 v1.0 10/15/2014 Yes MC-F-07-0050 v2.0 10/31/2014 Yes MC-F-14-0009 v1.0 2/17/2015 Yes MC-F-15-0051 v1.0 4/9/2015 No Non-conservative
- 1. Determination of 4kV Minimum Expected Voltage The LOCA loading condition, Case 1.4, was performed with the assumed minimum expected 230kV switchyard voltage of 101.0% to establish the minimum expected 4kV bus voltage. This resulted in Minimum Expected Voltages (MEV) of 93.31% for Bus 1F and 93.26% for Bus 1G, as seen in Attachment 1. All safety-related loads had adequate voltage levels for this case.
Table 3. Minimum Expected 4kV Steady-State Voltage with 230kV Grid at 101%.
ETAP Study 230kV Reference 4.16kV Min. Expected Train Case Bus Voltage Voltage (Attach. 3) 1F Load Flow 93.31%
101.0%
1G Case 1.4 93.26%
- 2. Determination of 4kV Minimum Required Voltage and Minimum Starting Voltages Normal steady-state, LOCA steady-state, LOCA group motor starting, and individual motor starting cases were studied to determine the lowest 4kV bus voltage that could supply adequate voltage to all safety-related loads. Based on the existing calculations and the incorporation of outstanding modifications (MCs), the limiting component was found for each train, as summarized in Table 4. Based on the required starting or steady-state voltage of this component, the corresponding pre-start or steady-state voltage at its relative 4kV bus was determined to be the MRV. This MRV was NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 8 of 11 considered for all study cases to verify that all other components achieved adequate voltage to perform the required safety functions. The lowest voltage at the 4kV bus during the LOCA group motor start at the MRV is the MSV (maximum value for the existing LOSP Relay dropout setting).
Table 4. Minimum Pre-start and Starting Voltages for LOCA Group Start Motors.
(See Attachment 1) 4.16kV Bus MRV 4.16kV Bus MSV Limiting ETAP Limiting Train (t=0-) (t=0+) Study Case Device(s)
Motor Starting E4 MOV 3024 A, 1F 88.92% 81.93%
5F LOCA Start E5 MOV 3024 B Motor Starting B4 MOV 2769B, 1G 88.60% 81.19%
5G LOCA Start C2 MOV 3478B The LOCA safety injection group motor starting scenario was simulated in Case 5F LOCA Start with Bus 1F pre-start voltage forced to the MRV of 88.92%. All safety-related loads fed by Bus 1F maintained adequate starting voltage.
The LOCA motor starting study case 5G LOCA Start was performed with the Bus 1G pre-start voltage forced to the MRV of 88.60%. All safety-related loads fed by Bus 1G maintained adequate starting voltage, except the 3232 MOVs and MOV 3318A on 600V MCC 1V. The 3232 MOVs are acceptable per calculation SE-91-1925-14-PE (Reference 14), as the maximum load occurs at the end of the close of the stroke when the MOVs are already running (see Assumption 3). MOV 3318A would achieve the required voltage by replacement of the thermal overload (TOL) heater with one of a lower resistance.
The post safety injection groups MOV Group A (7F LOCA ST A and 7G LOCA ST A) and MOV Group B (4F MOV START and 4G MOV START) case runs were performed with the 4kV buses forced to their respective MRV. All MOVs in these test groups were capable of starting and maintained adequate terminal voltage.
The normal steady-state cases 1.3F and 1.3G were performed with the 4kV buses forced to their respective MRV. All safety-related loads have positive voltage margin in this scenario.
The LOCA steady-state cases 1.4F and 1.4G were performed with the 4kV buses forced to their respective MRV. All safety-related loads have positive voltage margin in this scenario.
Finally, the individual motor starting cases (4F Individual and 4G Individual) were performed with the 4kV buses forced to their respective MRV. All safety-related loads were capable of starting and maintained adequate terminal voltage.
Table 5. ETAP Degraded Grid Case Runs in FNP1V07.
Configuration Module Study Case Load Cat. Gen. Cat. Utility Voltage*
Case_1.3 LF Case 1.3 Normal Min-Exp 101.43%
Case_1.3 LF Case 1.3F Normal DGG-TOL-F 96.86%
Case_1.3 LF Case 1.3G Normal DGG-TOL-G 96.18%
Case_1.4 LF Case 1.4 LOCA.SS Min-Exp 101.45%
Case_1.4 LF Case 1.4F LOCA.SS DGG-F 97.25%
NMP-ES-039- F02 NMP-ES-039-001
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J.M. Farley Nuclear Plant SE-SNC529029-001 9 of 11 Case_1.4 LF Case 1.4G LOCA.SS DGG-G 97.01%
Case_1.4 MS 4F MOV Start LOCA.SS DGG-F 97.25%
Case_1.4 MS 4G MOV Start LOCA.SS DGG-G 97.01%
Case_1.4 MS 4FIndividual LOCA.SS DGG-F 97.25%
Case_1.4 MS 4GIndividual LOCA.SS DGG-G 97.01%
Case_1.5 MS 5F LOCA Strt LOCA.ST DGG-F 96.30%
Case_1.5 MS 5G LOCA Strt LOCA.ST DGG-G 96.08%
Case_1.7 MS 7F LOCA ST A MOV Group A MOV Grp A-F 97.22%
Case_1.7 MS 7G LOCA ST A MOV Group A MOV Grp A-G 96.96%
- Utility voltage is the ETAP input in percent of 230kV representing the voltage behind the system impedance. Actual 230kV switchyard voltage in each plant configuration and loading category is lower than these values.
Refer to Attachment 1 for a summary of safety-related load voltages and Attachments 2 through 4 for ETAP output results for the case studies shown in Table 5. See Table 6 for a list of motors and MOVs listed in Attachment 1 with less than 0.5% margin between their minimum voltage requirements and their degraded motor starting or steady-state voltages from the above case studies.
Table 6. Low Degraded Voltage Margin Motors and MOVs per Attachment 1.
Motor Name Case Study Voltage Req. Voltage Margin MOV 8803A MS 1.5F 75.30% 75.78% 0.48%
MOV 3024A MS 1.5F 72.87% 72.87% 0.00%
MOV 3024B MS 1.5F 72.87% 72.87% 0.00%
LCV 0115B MS 1.5F 74.96% 75.42% 0.46%
MOV V516 MS 1.5G 75.09% 75.59% 0.50%
MOV 8803B MS 1.5G 68.35% 68.76% 0.41%
MOV 8100 MS 1.5G 68.35% 68.63% 0.28%
MOV 3232A MS 1.5G 73.19% 71.32% -1.87%*
MOV 3232B MS 1.5G 68.02% 66.29% -1.73%*
MOV 3232C MS 1.5G 68.02% 66.29% -1.73%*
LCV 0115D MS 1.5G 68.35% 68.74% 0.39%
MOV 3318A MS 1.5G 70.00% 69.93% -0.07%**
MOV 2769B MS 1.5G 68.65% 68.65% 0.00%
MOV 3478B MS 1.5G 70.41% 70.41% 0.00%
Ctrl Rm Press Supply Fan B MS 1.5G 74.00% 74.23% 0.23%
Ctrl Rm HVAC Blower 1B LF 1.4G 90.00% 90.12% 0.12%
Ctrl Rm Rad Monitor B LF 1.3G 90.00% 88.31% -1.69%***
- see Assumption 3 for undervoltage justification
- recommended for TOL replacement
- see Attachment 1, Note 6 for undervoltage justification
- 3. Determination of DVR Time Delay The safety injection group motors (5F LOCA Start and 5G LOCA Start motors) were modeled in ETAP with available dynamic data from SE-90-1845-2-PE (Reference 12). A NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 10 of 11 transient analysis was performed with the prestart voltage at the 4kV buses set to the MRV. As shown in transient analysis plots in Attachment 5, all SI motors were capable of starting and reaching full speed within 6.5 seconds. Therefore, a DVR time delay of greater than 6.5 seconds is required. In this scenario, if the grid conditions do not recover and the relay does not reset, the DVR is expected to time out and transfer the loads to the diesel generators. In the ETAP transient analysis of the safety injection with the grid at 101%, the 4kV Bus 1F and 1G voltages recover above the MEV faster than the DVR time delay of 6.5 seconds. In this scenario, the DVR would reset, preventing a spurious trip from the offsite power source.
Additionally, during a sustained degraded voltage condition concurrent with a LOCA, the DVR must trip before the diesel generator start time of 12 seconds as specified in the FSAR. The DVR must also trip before any thermal overload (TOL) relays trip from overcurrent. Per Attachment 6, the TOL for LCV0115B has an expected trip time of less than 12 seconds during starting with a voltage below its individual motor starting requirement. MOV TOL trip times were calculated as the average trip time from calculation SE-94-0-0378-001, Attachment 4 (Reference 16) corresponding to the TOL starting multiple calculated per the methodology of SE-94-0-0378-001 multiplied by the MOVs minimum voltage requirement for motor starting (see Attachment 1). TOL trip times for safety-related pumps and fans were calculated similarly in Attachment 6 using data from calculations SE-94-0-0378-001 (Reference 16) and SE-90-1714-12, Attachments 4 and 5 (Reference 18). This timing analysis yields a minimum TOL trip time of 11.5 seconds (at LCV0115B).
. . 9400378001
=
where = 1.25 . ()
Note that trip times for overcurrent relays (OCRs) were not considered for the DVR maximum time settings because the 4kV safety injection motors with OCRs are capable of starting at voltages as low as 75%. Below this voltage the existing LOSP Relay should be expected to trip prior to any OCR. See Figure 2 for a visualization of degraded voltage protection.
Given the above constraints, the DVRs must have a time setting between analytical limits of 6.5 seconds and 11.5 seconds. Considering the need to keep safety-related loads on the grid as long as possible while also preventing safety-related motors from tripping due to extended overload conditions, this calculation recommends a setting of 9.0 seconds. Anticipated maximum relay drift is 0.82% of setting per Design Input 3. This yields an upper allowable value for the timing function of 11.4 seconds (11.5 sec./100.82%) and a lower allowable value of 6.6 seconds (6.5 sec./99.18%).
Accounting for calibration tolerances of +/-0.5 seconds per Assumption 5 there is sufficient operating range for a setting of 9.0 seconds. Instrument calibration accuracy, radiation, and seismic tolerances are all assumed to be negligible.
NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-001 11 of 11 Table 7. DVR Time Delay Operating Range (seconds).
Lower Nominal Upper Analytical Allowable Calib. Trip Calib. Allowable Analytical Limit Value Limit Setpoint Limit Value* Limit 6.5 6.6 8.5 9.0 9.5 11.4 11.5
- Tech. Spec. DVR Time Setting Requirement 95.00%
93.00% MEV DVR RESET 91.00% DVR DROPOUT 89.00% MRV 87.00%
85.00%
83.00% Grid at 101%
81.00% 4kV Pre-Start at MRV MSV 79.00% Existing LOSP Tap 77.00% Setting per Reference 11 75.00%
-0.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 Figure 2. Degraded voltage protection scheme.
Attachments:
- 1. Summary of Steady-State and Starting Voltages at Minimum Required Voltage
- 2. ETAP Output Reports - NORMAL Load Flow (Configuration Case 1.3)
- 4. ETAP Output Reports - Motor Starting (Configuration Cases 1.4, 1.5, and 1.7)
- 5. Safety Injection Transient Plots
- 6. Thermal Overload Trip Time Tables
Joseph M. Farley Nuclear Plant, Units 1 and 2 Technical Specification 3.3.5 Loss of Power Diesel Generator Start Instrumentation Supplement to License Amendment Request Enclosure 2 FNP Unit 2 Calculation SE-SNC529029-002 Minimum Expected Voltage Study (Attachments to calculation not included)
SOUTHERN COMPANY A Southern Nuclear Design Calculation En*ro to&- !llur'"'riJ' Calculation Number:
SE-SNC529029-002 Plant: I Unit: I Discipline:
J.M. Farley Nuclear Plant
Title:
Unit 2 Minimum Expected Voltage Study 01 ltl2 01&2 I
Subject:
Electrical AC System Analysis Purpose I Objective:
Determine safe operating limits of Unit 2 under degraded grid conditions System or Equipment Tag Numbers:
R01,R11,R15,R16,R17 Contents Topic Page Attachments #of (Computer Printouts, Technical Papers, Pages Sketches, Correspondence)
Version History 1 1. Summary of Steady-State and Starting 9
Design Inputs 1 Voltages at Minimum Required Voltage References 1 2. ETAP Output Reports- NORMAL Load Flow 91 Purpose of Calculation 2 3. ETAP Output Reports - LOCA Load Flow 99 Summary of Conclusions 2 4. ETAP Output Reports - Motor Starting 50 Methodology 4 5. Safety Injection Transient Plots 1 Assumptions 5 6. Thermal Overload Trip Time Tables 2 Acceptance Criteria 6 7. AC Voltage Drop from PT to DVR 1 Body of Calculation 6 Total# of Pages including 265 cover sheet & Attachments:
Nuclear Qualit Level It! Safe -Related D Version Record Version Originator Reviewer Approval1 Approval2 No. Description Prlnt.d Na11111 lniUaJ I Data Printed Name lniUal/ Data Prtnt.d Name lniUal/ Data Prlnt.c!Name lniUal/ Data .
Chris Harwell Matt Lane Kevin Uttrell J...,!-11'4 ,1/ltrlt.t Y' 1.0 Issued per RER SNC529029, v1.0 c..t~
,,~)1{"
~
w~~~/(f ~V-J (,,,~ ,,.; ht11 6-J'I-15' Notes: An OE search has been performed and the results are documented m the Methodology Section.
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 1 of 11 Version History:
Version 1.0: Initial version issued for RER SNC529029.
Design Inputs:
- 1. SE-94-0470-007, Ver. 7.0, Unit 2 As-Built Load Study: Primary calculation input; source of ETAP model and methodology used for case study runs.
- 2. SE-94-0470-005, Ver. 6.0, Unit 2 Load Study Summary: LOCA starting and steady-state requirements tables modified for use as Attachment 1 of this calculation.
- 3. SJ-SNC529029-001, Ver. 1.0, Determination Of Setpoints, Reset Points, And Loop Uncertainties For 4160V Safety-Related Degraded Voltage Relay (DVR) Loops (Buses 1F, 2F, 1G And 2G)
References:
- 1. GDC 17, General Design Criteria for Nuclear Power Plants 17
- 2. IEEE Standard 399-1997, IEEE Recommended Practice for Industrial and Commercial Power Systems Analysis
- 3. NRC Regulatory Issue Summary 2011-12, Revision 1, Adequacy of Station Electric Distribution System Voltages: Guidance for degraded grid analysis acceptance criteria and methodology
- 4. Farley Nuclear Plant Units 1 & 2 Tech Spec Bases, Rev. 66
- 5. Farley Nuclear Plant Unit 2 Tech Spec, Amendment 193
- 6. Farley Nuclear Plant Units 1 & 2 FSAR, Rev. 26, March 2015
- 7. SM-90-1653-002, Ver. 23.0, Reduced Voltage Torque/Thrust Capability for Gate &
Globe Valves in the FNP MOV Program
- 8. SM-90-1653-009, Ver. 8.0, Reduced Voltage Torque Capability for Butterfly Valves in the FNP MOV Program
- 9. SM-1053039201-001, Ver. 1.0, Develop Design Basis Calculations for the Penetration Room Filter Dampers
- 10. DOEJ-FRSNC529029-M001, Ver. 1.0, Evaluation of Reduced Voltage Requirements for Motor Operated Valves for use in the Degraded Voltage Protection Plan
- 11. E-035.02.A, Ver. 7.0, Setting of Protective Relays for 4.16kV Auxiliary Power System
- 12. SE-90-1845-2-PE, Ver. 8.0, Large, Small, and SBO Diesel Dynamic Study
- 13. SE-91-1976-1, Ver. 6.0, Motor Starter Control Circuit Study
- 14. SE-91-1925-14-PE, Ver. 1.0, MOV3232A,B,C: Terminal Voltage at End of Stroke
- 15. SE-99-9472-001, Ver. 1.0, Stability Review for LOSP/DGG Relay Operation
- 16. SE-94-0-0378-001, Ver. 5.0, MOV Combination Starter Component Sizes and Settings
- 17. SE-99-0-2010-001, Ver. 0.0, Verification Package for Computer Software Used to Calculate MOV Thermal Overload Heater Sizes
- 18. SE-90-1714-12, Ver. 4.0, Overload Heater Sizing and Resistance
- 20. 1995 SER, February 23, 1995, Safety Evaluation for Degraded Grid Voltage Relay Set Points
- 21. GEH-1768G, GE Instructions: Undervoltage Relays
- 22. MC-F-06-0057, Ver. 1.0
- 23. MC-F-06-0144, Ver. 1.0 NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 2 of 11
- 24. MC-F-07-0015, Ver. 1.0
- 25. MC-F-07-0081, Ver. 1.0
- 26. MC-F-07-0117, Ver. 1.0
- 27. MC-F-08-0077, Ver. 1.0
- 28. MC-F-08-0092, Ver. 1.0
- 29. MC-F-08-0193, Ver. 1.0
- 30. MC-F-09-0044, Ver. 1.0
- 31. MC-F-09-0073, Ver. 1.0
- 32. MC-F-09-0075, Ver. 1.0
- 33. MC-F-09-0077, Ver. 1.0
- 34. MC-F-09-0172, Ver. 1.0
- 35. MC-F-10-0064, Ver. 1.0
- 36. MC-F-10-0057, Ver. 1.0
- 37. MC-F-10-0071, Ver. 1.0
- 38. MC-F-10-0132, Ver. 2.0
- 39. MC-F-10-0133, Ver. 1.0
- 40. MC-F-11-0007, Ver. 1.0
- 41. MC-F-11-0005, Ver. 1.0
- 42. MC-F-11-0038, Ver. 1.0
- 43. MC-F-11-0080, Ver. 1.0
- 44. MC-F-12-0028, Ver. 1.0
- 45. MC-F-12-0058, Ver. 1.0
- 46. MC-F-12-0064, Ver. 1.0
- 47. MC-F-13-0031, Ver. 1.0
- 48. MC-F-13-0067, Ver. 1.0
- 49. MC-F-14-0021, Ver. 1.0
- 50. CCN-F-13-0001, Ver. 1.0
- 51. CR 10063545
- 52. CAR 257139
- 53. 57SV-S32-002-1, Emergency Buses 1E, 1F, and 1G Undervoltage Relay Instrument FT&C, Attachment 3.
Purpose of Calculation:
The purpose of this calculation is to determine the operating range of Farley Nuclear Plant Unit 2 under degraded voltage conditions at the 230kV grid to meet the requirements of safety-related loads using the guidance in Regulatory Issue Summary RIS 2011-12, Revision 1 (Reference 3). This operating range is used by other calculations to determine Degraded Voltage Relay (DVR) settings to automatically transfer safety-related loads from an unacceptable offsite power source to an onsite power source.
Summary of
Conclusions:
- 1. The minimum voltage that meets the steady-state requirements for all safety-related loads during the Normal and LOCA loading cases for Farley Unit 2 is determined, and is documented in Table 1a as the Minimum Required Voltage (MRV). Refer to Attachments 2 and 3 for ETAP output reports.
NMP-ES-039- F02 NMP-ES-039-001
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J.M. Farley Nuclear Plant SE-SNC529029-002 3 of 11
- 2. The required starting voltage at the safety-related motors and MOVs is satisfied for the motor starting cases established in calculation SE-94-0470-005 (Design Input 2). Refer to Attachment 4 for ETAP output reports.
- 3. Some of the safety-related MCCs have voltages below the minimum level required for motor control circuits during the safety injection group motor start; however, per calculation SE-91-1976-1 (Reference 13), these MCCs are acceptable because with the 4kV buses at the MRV, they have the minimum required relay pickup voltage to energize upon an SI signal prior to the motor starting transient. Additionally, load voltages remain above the relay drop-out voltage. See Attachment 1 for motor starting bus voltages.
- 4. The MRV, shown in Table 1a, is lower than the DVR Lower Analytical Limit (LAL). This LAL is selected to provide margin below the DVR setpoint uncertainty range determined in Design Input 3 and above the MRV. Thus the dropout voltage of each DVR will be set such that the minimum tolerance is above the MRV for the 4160V buses 2F and 2G.
- 5. The Minimum Expected Voltage (MEV), shown in Table 1a, is higher than the DVR Upper Analytical Limit (UAL). This UAL is selected to provide margin above the DVR setpoint uncertainty range determined in Design Input 3 and below the MEV. Thus the reset voltage of each DVR will be set such that the maximum tolerance is below the MEV for the 4160V buses 2F and 2G.
- 6. The total available electrical margin available is 1.54% and 0.99% for 4160V buses 2F and 2G, respectively, per the results in Table 1a.
- 7. The DVR time delay should be set, with tolerances, so that the time is not less than the Safety Injection (SI) Transient Time, and not greater than the minimum thermal overload (TOL) relay trip time, as shown in Table 1b. It is the recommendation of this calculation to set the DVR time delay at 8.0 seconds to keep the safety-related loads on the grid as long as possible while also preventing safety-related motors from tripping due to extended overload conditions. Safety Injection Transient plots are included in Attachment 5, and TOL trip times for SI motors when below the MSV are listed in Attachment 6.
- 9. The dropout voltage of each LOSP Relay is below the Minimum Starting Voltage (MSV) shown in Table 1a for the 4160V buses 2F and 2G, which occurs immediately after a LOCA group motor start, so there is no expected interaction between the new DVR and the existing LOSP Relay.
Table 1a. Summary of Unit 2 Degraded Voltage Relay Operating Range Results.**
4.16kV Bus 4.16kV Bus DVR Margin 4.16kV 4.16kV MEV DVR UAL MRV DVR LAL (MEV-MRV)
Bus Bus MSV (Attach. 2) (Attach. 1) - (UAL-LAL) 2F 93.44% 92.67% 88.71% 89.48% 81.65% 1.54%
2G 93.69% 93.19% 89.50% 89.99% 82.36% 0.99%
Table 1b. Summary of Unit 2 DVR Timing Analysis.
4.16kV SI Transient Start Time TOL Trip Time DVR Trip DVR Time Delay Bus (Attach. 5) (Attach. 6) Setpoint Allowable Value*
2F 6.0 seconds 10.0 seconds 8.0 seconds 9.9 seconds 2G
- Tech. Spec. DVR Time Setting Requirement NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 4 of 11 Methodology:
The computer model of Farley Unit 2, FNP2V01, was developed with ETAP Version 12.6.0N software package for calculation SE-94-0470-007 (Design Input 1). This calculation uses ETAP software to perform analysis of the auxiliary system including load flow, motor starting, and transient studies. Refer to the ETAP User Guide 12.6 for additional information regarding the ETAP program.
Version 6.0 of calculation SE-94-0470-007 ETAP model (FNP2V01) was utilized for this calculation. While this study was being finalized, the Unit 2 load study model was also being finalized. Re-analysis utilizing the latest file (FNP2V02) was not required per discussions with SNC.
Before the ETAP model was used for this study, outstanding modification calculations (MCs) against base calculation (BC) SE-94-0470-007 (Design Input 1) were merged into the base revision in order of MC approval dates. See Table 2 in the calculation body for a detailed list of merged MCs. CR 10063545 (Reference 51) was addressed utilizing CAR 257139 (Reference 52) load changes, which were also incorporated into the ETAP model as part of this calculation. The ETAP model was then used to determine several values at the 4kV buses 2F and 2G: the Minimum Expected Voltage, the Minimum Required Voltage, the Minimum Starting Voltage, and the Safety Injection Transient Time (See example of the relationship of these values as shown in Figure 1).
The methodology for each is described below.
- 1. Minimum Expected Voltage (MEV): The MEV is calculated as the 4kV bus voltage during LOCA steady-state with a 230kV switchyard voltage of 101.0%. In the Farley Unit 2 ETAP model FNP2V01, this is the Load Flow Study Case 2.4.
- 2. Minimum Required Voltage (MRV): The MRV is the maximum requirement of the following three calculations.
- a. Using maximum expected non-accident bus loading, determine minimum acceptable steady-state voltage for normal operation of Class 1E loads. This was performed using ETAP load flow study cases 2.3F and 2.3G.
- b. Using maximum expected accident loading, determine the minimum pre-start voltage that provides acceptable Class 1E motor starting (e.g. during LOCA group motor starting). This was performed using ETAP load flow study cases 2.4F and 2.4G.
- c. Using maximum expected accident loading, determine the minimum steady-state voltage that provides acceptable Class 1E motor operation and starting for individual motors. This was performed using ETAP motor starting study cases 4F MOV Start, 4G MOV Start, 5F LOCA Start, 5G LOCA Start, 7F LOCA ST A, and 7G LOCA ST A.
- 3. Minimum Starting Voltage (MSV): The MSV is calculated as the lowest voltage at the 4kV bus during a LOCA group start transient (ETAP motor starting study cases 5F LOCA Start and 5G LOCA Start) with the pre-start voltage at the MRV.
- 4. Safety Injection Transient Time: The SI Transient Time is calculated as the minimum time for the SI group motors to start and reach steady-state with the 4kV buses at the NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 5 of 11 MRV. The ETAP Transient Study Case used to analyze the SI group start is developed as a part of this calculation.
MEV MRV SI Transient Time MSV Figure 1. Example SI transient showing location of MEV, MRV, MSV, and SI Transient Time.
The OE search was performed using the following keywords:
ETAP Degraded Grid Relay Date OE Problem Relevance / Action /
Source Impact Resolution 11/19/2009 INPO OE30473: Potential Inaccurate No motors Only applies to Induction Motor Models in ETAP- modeled at older versions of Davis-Besse Unit 2: greater than ETAP. No action The cumulative load increases due 100% loading. is required.
to induction machine modeling techniques may result in non-conservative AC Power System Analyses. For motors operating at greater than 100 percent, allowing efficiency at 100 percent motor load to adjust results in a non-conservative estimate (under prediction) of EDG loading due to the ETAP extrapolation of motor efficiency beyond 100 percent loading.
Assumptions:
- 1. A minimum expected grid voltage of 101.0% at the 230kV Reference Bus is assumed and utilized in the ETAP model based on contingency studies defined by the FSAR (Reference 6).
- 2. Loads listed in Attachment 1 with steady-state voltages that do not have motor starting criteria are assumed to be able to endure a transient motor starting situation.
- 3. Low motor starting voltage for the 3232 MOVs on 600V MCC 2V can be considered acceptable during block starting since the MOVs start with no load. Per SCS Calculation NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 6 of 11 SE-91-1925-14-PE (Reference 14), the maximum load occurs at the end of the close of the stroke when the motors are already running.
- 4. A constant grid impedance of 0.87+j1.125 percent of 100MVA base is assumed and utilized in the ETAP model per calculation SE-94-0470-007, Attachment C (Design Input 1).
- 5. ABB 27N calibration limits are determined to be +/-0.5 seconds from the Plant Hatch Surveillance Procedure for degraded voltage alarm relays 57SV-S32-002-1, Emergency Buses 1E, 1F, and 1G Undervoltage Relay Instrument FT&C, Attachment 3 (Reference 53).
Acceptance Criteria:
- 1. The required steady-state voltages at the motor terminals are established in calculation SE-94-0470-005 (Design Input 2). Non-1E motors/loads are allowed to be below 90%
rated voltage, since they are not required to mitigate a design basis event.
- 2. The required starting voltages at the safety-related motors are established in calculation SE-94-0470-005 (Design Input 2). All safety-related motors must be capable of starting at the corresponding MRV.
- 3. The required MOV starting voltages are established in mechanical torque calculations SM-90-1653-002 (Reference 7), SM-90-1653-009 (Reference 8) and SM-1053039201-001 (Reference 9), as listed in SE-94-0470-005 (Design Input 2). These starting requirements have been updated by DOEJ-FRSNC529029-M001 (Reference 10). All safety-related MOVs must be capable of starting at the corresponding MRV.
- 4. With the 4kV bus pre-start voltage at the MRV, the SI transient time should be less than the minimum TOL trip time to prevent safety-related equipment from stalling or tripping on overcurrent during a degraded voltage condition.
- 5. The MRV must be lower than the LAL, and the MEV must be higher than the UAL. The Analytical Limits must be selected to provide margin above and below the setpoint uncertainty range determined in Design Input 3.
Body of Calculation:
ETAP was used to simulate normal and accident conditions with a concurrent degraded grid condition. Outstanding MCs and CCNs (References 22-50) against SE-94-0470-007 (Design Input 1) were merged into the ETAP base revision of Farley Unit 2 model FNP2V01 in accordance with Table 2 before any case studies were analyzed. The methodology used in Design Input 1 was followed to set up the ETAP study cases. The 230kV source voltage was modified to obtain the desired voltage at the 4kV bus being studied for each case.
Table 2. List of Outstanding MCs Merged into ETAP Model Base Revision.
Approval MC Number Date Merged Notes MC-F-06-0057 v1.0 3/22/2006 No Removes load MC-F-06-0144 v1.0 9/28/2006 Yes MC-F-07-0015 v1.0 2/07/2007 No Removes load MC-F-07-0081 v1.0 3/11/2008 Yes MC-F-07-0117 v1.0 12/13/2007 Yes NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 7 of 11 Table 2. List of Outstanding MCs Merged into ETAP Model Base Revision.
Approval MC Number Date Merged Notes MC-F-08-0092 v1.0 9/15/2008 Yes MC-F-08-0077 v1.0 6/6/2008 Yes MC-F-08-0193 v1.0 12/19/2008 No Removes load MC-F-09-0044 v1.0 3/23/2009 Yes MC-F-09-0073 v1.0 7/30/2009 Yes Merged because MDC is as-built MC-F-09-0075 v1.0 7/30/2009 Yes MDC is closed, but not yet closed by site MC-F-09-0077 v1.0 7/30/2009 Yes Merged because MDC is as-built MC-F-09-0172 v1.0 12/30/2009 Yes MC-F-10-0064 v1.0 4/13/2010 Yes MDC is closed, but not yet closed by site MC-F-10-0071 v1.0 6/13/2010 Yes MC-F-10-0057 v1.0 6/13/2010 Yes MC-F-10-0133 v1.0 12/7/2010 Yes MC-F-11-0007 v1.0 2/21/2011 No Reduces load MC-F-11-0005 v1.0 3/10/2011 Yes MDC is closed, but not yet closed by site MC-F-10-0132 v2.0 8/17/2011 Yes MC-F-11-0038 v1.0 10/12/2011 Yes MC-F-12-0028 v1.0 10/8/2012 Yes MC-F-12-0064 v1.0 2/7/2013 Yes CCN-F-13-0001 v1.0 3/5/2013 Yes MC-F-11-0080 v1.0 4/18/2013 Yes MC-F-13-0031 v1.0 9/5/2013 No Removes load MC-F-14-0021 v1.0 11/7/2014 Yes MC-F-12-0058 v1.0 12/18/2014 Yes MC-F-13-0067 v1.0 2/9/2015 Yes
- 1. Determination of 4kV Minimum Expected Voltage The LOCA loading condition, Case 2.4, was performed with the assumed minimum expected 230kV switchyard voltage of 101.0% to establish the minimum expected 4kV bus voltage. This resulted in minimum expected 4kV voltages (MEV) of 93.44% for Bus 2F and 93.69% for Bus 2G, as seen in Attachment 1. All safety-related loads had adequate voltage levels for this case.
Table 3. Minimum Expected 4kV Steady-State Voltage with 230kV Grid at 101%.
ETAP 230kV Reference 4.16kV Min. Expected Train Study Case Bus Voltage Voltage (Attach. 3) 2F Load Flow 93.44%
101.0%
2G Case 2.4 93.69%
NMP-ES-039- F02 NMP-ES-039-001
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J.M. Farley Nuclear Plant SE-SNC529029-002 8 of 11
- 2. Determination of 4kV Minimum Required Voltage and Minimum Starting Voltages Normal steady-state, LOCA steady-state, LOCA group motor starting, and individual motor starting cases were studied to determine the lowest 4kV bus voltage that could supply adequate voltage to all safety-related loads. Based on the existing calculations and the incorporation of outstanding modifications (MCs), the limiting component was found for each train, as summarized in Table 4. Based on the required starting or steady-state voltage of this component, the corresponding pre-start or steady-state voltage at its relative 4kV bus was determined to be the MRV. This MRV was considered for all study cases to verify that all other components achieved adequate voltage to perform the required safety functions. The lowest voltage at the 4kV bus during the LOCA group motor start at the MRV is the MSV (maximum value for the LOSP Relay dropout setting).
Table 4. Minimum Pre-start and Starting Voltages for LOCA Group Start Motors.
(See Attachment 1) 4.16kV Bus MRV 4.16kV Bus MSV Limiting ETAP Train Limiting Device (t=0-) (t=0+) Study Case Motor Starting B3 Serv Wtr MOV 515 2F 88.71% 81.65%
5F LOCA Start B4 Serv Wtr MOV 517 Motor Starting B4 MOV 2769B, 2G 89.50% 82.36%
5G LOCA Start C2 MOV 3478B The LOCA safety injection group motor starting scenario was simulated in case 5F LOCA Start with Bus 2F pre-start voltage forced to the MRV of 88.71%. All safety-related loads fed by Bus 2F maintained adequate starting voltage.
The LOCA safety injection group motor starting scenario was simulated in case 5G LOCA Start with Bus 2G pre-start voltage forced to the MRV of 89.50%. All safety-related loads fed by Bus 2G maintained adequate starting voltage, except the 3232 MOVs on 600V MCC 2V. The 3232 MOVs are acceptable per calculation SE-91-1925-14-PE (Reference 14), as the maximum load occurs at the end of the close of the stroke when the MOVs are already running (see Assumption 3).
The post safety injection groups MOV Group A (7F LOCA ST A and 7G LOCA ST A) and MOV Group B (4F MOV START and 4G MOV START) case runs were performed with the 4kV buses forced to their respective MRV. All MOVs in these test groups were capable of starting and maintained adequate terminal voltage.
The normal steady-state cases 2.3F and 2.3G were performed with the 4kV buses forced to their respective MRV. All safety-related loads have positive voltage margin in this scenario.
The LOCA steady-state cases 2.4F and 2.4G were performed with the 4kV buses forced to their respective MRV. All safety-related loads have positive voltage margin in this scenario.
NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 9 of 11 Finally, the individual motor starting cases (4F Individual and 4G Individual) were performed with the 4kV buses forced to their respective MRV. All safety-related loads were capable of starting and maintained adequate terminal voltage.
Table 5. ETAP Degraded Grid Case Runs in FNP2V01.
Configuration Module Study Case Load Cat. Gen. Cat. Utility Voltage*
Case_2.3 LF Case 2.3 Normal Min-Exp 101.40%
Case_2.3 LF Case 2.3F Normal DGG-TOL-F 96.25%
Case_2.3 LF Case 2.3G Normal DGG-TOL-G 96.63%
Case_2.4 LF Case 2.4 LOCA.SS Min-Exp 101.43%
Case_2.4 LF Case 2.4F LOCA.SS DGG-F 96.90%
Case_2.4 LF Case 2.4G LOCA.SS DGG-G 97.40%
Case_2.4 MS 4F MOV Start LOCA.SS DGG-F 96.90%
Case_2.4 MS 4G MOV Start LOCA.SS DGG-G 97.40%
Case_2.4 MS 4FIndividual LOCA.SS DGG-F 96.90%
Case_2.4 MS 4GIndividual LOCA.SS DGG-G 97.40%
Case_2.5 MS 5F LOCA Strt LOCA.ST DGG-F 95.95%
Case_2.5 MS 5G LOCA Strt LOCA.ST DGG-G 96.48%
Case_2.7 MS 7F LOCA ST A MOV Grp A MOV Grp A-F 96.70%
Case_2.7 MS 7G LOCA ST A MOV Grp A MOV Grp A-G 97.23%
- Utility voltage is the ETAP input in percent of 230kV representing the voltage behind the system impedance. Actual 230kV switchyard voltage in each plant configuration and loading category is lower than these values.
Refer to Attachment 1 for a summary of safety-related load voltages and Attachments 2 through 4 for ETAP output results for the case studies shown in Table 5. See Table 6 for a list of motors and MOVs listed in Attachment 1 with less than 0.5% margin between their minimum voltage requirements and their degraded motor starting or steady-state voltages from the above case studies.
Table 6. Low Degraded Voltage Margin Motors and MOVs per Attachment 1.
Motor Name Case Study Voltage Req. Voltage Margin MOV 3478A MS 2.5F 75.99% 76.41% 0.42%
MOV 2769A MS 2.5F 73.93% 74.34% 0.41%
MOV V515 MS 2.5F 84.86% 84.86% 0.00%
MOV V517 MS 2.5F 84.86% 84.86% 0.00%
MOV 8811A MS 2.4F MOV 78.78% 78.95% 0.17%
Solatron Voltage Reg. LF 2.4F 77.00% 77.10% 0.10%
Mult Relay Cab 1A LF 2.4F 88.19% 88.41% 0.22%
MOV 3024C MS 2.5G 65.57% 65.85% 0.28%
MOV 3024D MS 2.5G 66.09% 66.69% 0.60%
MOV 8100 MS 2.5G 68.70% 68.94% 0.24%
MOV 3232A MS 2.5G 72.05% 71.28% -0.76%*
MOV 3232B MS 2.5G 72.57% 71.56% -1.01%*
MOV 3232C MS 2.5G 73.24% 72.48% -0.76%*
MOV 3318A MS 2.5G 70.00% 71.74% 1.74%
MOV V516 MS 2.5G 75.21% 75.40% 0.19%
NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 10 of 11 Table 6. Low Degraded Voltage Margin Motors and MOVs per Attachment 1.
Motor Name Case Study Voltage Req. Voltage Margin MOV 2769B MS 2.5G 68.65% 68.65% 0.00%
MOV 3478B MS 2.5G 70.41% 70.41% 0.00%
Ctrl Rm Press Supply Fan B MS 2.5G 74.00% 74.23% 0.23%
Ctrl Rm Rad Monitor LF 2.3G 90.00% 90.39% 0.39%
L5L Spent Fuel Pool Mon. LF 2.4G 90.00% 90.46% 0.46%
- see Assumption 3 for justification for negative margin
- 3. Determination of DVR Time Delay The safety injection group motors (5F LOCA Start and 5G LOCA Start motors) were modeled in ETAP with available dynamic data from SE-90-1845-2-PE (Reference 12). A transient analysis was performed with the prestart voltage at the 4kV buses set to the MRV. As shown in transient analysis plots in Attachment 5, all SI motors were capable of starting and reaching full speed within 6 seconds. Therefore, a DVR time delay of greater than 6 seconds is required. In this scenario, if the grid conditions do not recover and the relay does not reset, the DVR is expected to time out and transfer the loads to the diesel generators. In the ETAP transient analysis of the safety injection with the grid at 101%, the 4kV Bus 2F and 2G voltages recover above the MEV faster than the DVR time delay of 6 seconds. In this scenario, the DVR would reset, preventing a spurious trip from the offsite power source.
Additionally, during a sustained degraded voltage condition concurrent with a LOCA, the DVR must trip before the diesel generator start time of 12 seconds as specified in the FSAR. The DVR must also trip before any thermal overload (TOL) relays trip from overcurrent. Per Attachment 6, TOLs for five MOVs have expected trip times of less than 12 seconds during starting with a voltage below their individual motor starting requirement. MOV TOL trip times were calculated as the average trip time from calculation SE-94-0-0378-001, Attachment 4 (Reference 16) corresponding to the TOL starting multiple calculated per the methodology of SE-94-0-0378-001 multiplied by the MOVs minimum voltage requirement for motor starting (see Attachment 1). TOL trip times for safety-related pumps and fans were calculated similarly in Attachment 6 using data from calculations SE-94-0-0378-001 (Reference 16) and SE-90-1714-12, Attachments 4 and 5 (Reference 18). This analysis yields a minimum TOL trip time of 10 seconds (at MOV 3232B).
where 1.25 .
Note that trip times for overcurrent relays (OCRs) were not considered for the DVR maximum time settings because the 4kV safety injection motors with OCRs are capable of starting at voltages as low as 75%. Below this voltage the LOSP Relay should be expected to trip prior to any OCR. See Figure 2 for a visualization of degraded voltage protection.
NMP-ES-039- F02 NMP-ES-039-001
Plant: Calculation Number: Sheet:
J.M. Farley Nuclear Plant SE-SNC529029-002 11 of 11 Given the above constraints, the DVRs must have a time setting between analytical limits of 6.0 seconds and 10.0 seconds. Considering the need to keep safety-related loads on the grid as long as possible while also preventing safety-related motors from tripping due to extended overload conditions, this calculation recommends a setting of 8.0 seconds. Anticipated maximum relay drift is 0.82% of setting per Design Input 3. This yields an upper allowable value for the timing function of 9.9 seconds (10.0 sec./100.82%) and a lower allowable value of 6.1 seconds (6.0 sec./99.18%).
Accounting for calibration tolerances of +/-0.5 seconds per Assumption 5 there is sufficient operating range for a setting of 8.0 seconds. Instrument calibration accuracy, radiation, and seismic tolerances are all assumed to be negligible.
Table 7. DVR Time Delay Operating Range (seconds).
Lower Nominal Upper Analytical Allowable Calib. Trip Calib. Allowable Analytical Limit Value Limit Setpoint Limit Value* Limit 6.0 6.1 7.5 8.0 8.5 9.9 10.0
- Tech. Spec. DVR Time Setting Requirement 95.00%
93.00% MEV 91.00% DVR RESET DVR DROPOUT 89.00% MRV 87.00%
85.00% 4kV PreStart at MRV 83.00% Grid at 101%
81.00% MSV 79.00% LOSP Tap Setting 77.00% per Reference 11 75.00%
0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 Figure 2. Degraded voltage protection scheme.
Attachments:
- 1. Summary of Steady-State and Starting Voltages at Minimum Required Voltage
- 2. ETAP Output Reports - NORMAL Load Flow (Configuration Case 2.3)
- 4. ETAP Output Reports - Motor Starting (Configuration Cases 2.4, 2.5, and 2.7)
- 5. Safety Injection Transient Plots
- 6. Thermal Overload Trip Time Table
Joseph M. Farley Nuclear Plant, Units 1 and 2 Technical Specification 3.3.5 Loss of Power Diesel Generator Start Instrumentation Supplement to License Amendment Request Enclosure 3 FNP Units 1 & 2 Calculation SJ-SNC529029-001 Determination of Setpoints (Attachments to calculation not included)
Southern Nuclear Design Calculation SOUTHERN.\_ Calculation Number:
COMPANY EMrD ~vSnw...,_!RwiJ' SJ-SNC529029-001 Plant: 1Unit: 1Discipline:
Farley 01 02 ml1 &2 I&C
Title:
Determination Of Setpoints, Reset Points And Loop Uncertainties
Subject:
For The 4160V Safety-Related Degraded Voltage Relay (DVR) Loops 4160 KV Buses 1F, (Buses 1F, 2F, 1G And 2G) 1G,2F&2G Degraded Voltage Relavs Purpose I Objective:
Determine available margin System or Equipment Tag Numbers:
27F3 (3-1) 27F3 (2-3), 27F3 (1-2t 27G3 (3-1), 27G3 (2-3), 27G3 {1-2)
Contents Topic Page Attachments #of (Computer Printouts, Technical Papers, Pages Sketches Correspondence) "'
Attachment A, As-found/As-left (AF/AL) Analysis P.urpose of Calculation 1 21 of Alarm Relays Summary of Conclusions Attachment B,IB 7.4.1.7-7, ABB Instructions 1 12 Single Phase Voltage Relays Discussion of Methodoloav 3 Functional Description 7 Body of Calculation 8 Design Inputs 23 References 23 Total #of Pages Including 57 cover sheet &Attachments :
Version Record Version No. Desc tlon 1 Issued Note: An OE search has been performed and the results are documented in the Methodology section on page 5.
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 1 of 23 1.0 Purpose The purpose of this calculation is to determine the limiting allowable values, setpoints, reset points, available margin and loop uncertainties for the undervoltage function of the 4160V safety-related degraded voltage relay (DVR) loops (Buses 1F, 2F, 1G and 2G). The DVR relays used in this application have an integral user-settable time delay function. This calculation addresses the undervoltage function of the relay only. The timing function of the relays is address in calculations SE-SNC529029-001 (Reference 4) and SE-SNC529029-002 (Reference 8).
2.0 Summary of
Conclusions:
The limiting allowable values, setpoints, reset points, loop uncertainties and margins for the undervoltage function of the 4160V safety-related DVR loops (Buses 1F, 2F, 1G and 2G) are reflected in tables 1a and 1b below.
Table 1a - Allowable Values, Nominal Setpoints and Uncertainties (Undervoltage Function)
Refer to Figure 1, page 3 for illustrative presentation of Limiting Values Allowable Value Nominal Setpoint Loop Loop Under-At Primary At Relay At Primary At Relay Uncertainty Uncertainty voltage VAC VAC VAC VAC in % (VAC) at Function
(%4160V) (%4160V) 120VAC secondary Bus 1F Upper 3831.80a 3808.00 109.36 108.68 1.11 1.33 (Reset)b: (92.11) (91.54)
Lower 3760.75a 3784.55 107.45 108.13 1.11 1.33 (Trip): (90.40) (90.97)
Bus 1G Upper 3822.00a 3798.20 109.08 108.40 1.11 1.33 (Reset)b: (91.88) (91.30)
Lower 3751.65a 3775.10 107.19 107.86 1.10 1.32 (Trip): (90.18) (90.75)
Bus 2F Upper 3827.95a 3804.15 109.25 108.57 1.11 1.33 (Reset)b: (92.02) (91.45)
Lower 3757.25a 3780.70 107.35 108.02 1.10 1.32 (Trip): (90.32) (90.88)
Bus 2G Upper 3849.30a 3825.50 109.86 109.18 1.12 1.34 (Reset)b: (92.53) (91.96)
Lower 3778.25a 3802.05 107.95 108.63 1.11 1.33 (Trip): (90.82) (91.40)
NOTES:
a) Technical Specification Table 3.3.5-1.2 Loss of Power Diesel Generator Start Instrumentation recommended Allowable Value b) Upper value at primary side (Vp) adjusted to reflect 0.12V voltage drop on the secondary side (cable between the PT and DVR).
The calculated setpoint and allowable values account for an additional margin of 0.22 VAC on the secondary side of the PT (120 VAC buses).
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 2 of 23 Figure 1 - Limiting Values Diagram2 VAC at primary (VAC at relay)
(Vp) (Vr) 3858.82 Upper AL (110.13)
(92.76%)
Technical Specification 3831.801 (109.36)
Upper Allowable Value Reset Upper 3812.201 (108.80)
Calibration Limit Nominal Reset Setpoint 3808.001 (108.68)
Reset Lower 3803.801 (108.56)
Calibration Limit Setpoint Upper 3788.75 (108.25)
Calibration Limit Nominal Setpoint 3784.55 (108.13)
Setpoint Lower 3780.35 (108.01)
Calibration Limit Technical Specification 3760.75 (107.45)
Lower Allowable Value 3726.11 Lower AL (106.47)
(89.57%)
Notes:
- 2. Bus 1F is shown. Buses 1G, 2F and 2G are similar.
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 3 of 23 3.0 Discussion of Methodology Due to the simple configuration of this loop and the use of components traditionally not found in instruments loops, there are very few uncertainty terms that apply to this calculation. The loop consists of a potential transformer and an undervoltage relay with an integral user-settable time delay function. The uncertainties associated with the undervoltage function for the relays listed below are addressed in this calculation:
Bus 1F Bus 1G Bus 2F Bus 2G Q1R43E0001A27F312 Q1R43E0001B27G312 Q2R43E0001A27F312 Q2R43E0001B27G312 Q1R43E0001A27F323 Q1R43E0001B27G323 Q2R43E0001A27F323 Q2R43E0001B27G323 Q1R43E0001A27F331 Q1R43E0001B27G331 Q2R43E0001A27F331 Q2R43E0001B27G331 Due to the functional nature of this loop, the enhanced uncertainty methodology in section A.4.3 of DI-2 is followed as a guideline only. Vendor-provided uncertainty terms are in %
setting. Therefore, where necessary, the upper and lower uncertainty terms are derived separately. These terms are prefixed by a U and L respectively.
The following discussion addresses the justification and assumptions used in determining the applicable uncertainty terms and the channel statistical allowance (CSA) equation.
Each DVR loop consists of a transformer and relay. In order to use terminology consistent with DI-2, for the purposes of this calculation the transformer will be treated as the primary element and the relay as the rack comparator (bistable) instrument. There is no sensor in this loop. The pressure effects normally associated with the sensor will be considered in the calculation of the rack uncertainties (RPE term). Therefore the CSA is defined for this two element loop as:
(RD + RMTE )2 + (RCSA + RMTE )2 + RRA 2 + RTE 2 +
CSA = + ( BIAS + EA)
RPE 2 + PEA 2 + PMA 2 For this application: RCSA and RMTE are considered dependent variables. RRA, RTE, RPE and PEA are considered independent variables with respect to RCSA and RMTE and each other.
RD is not combined with any other term since it is derived from plant data which includes any contributions associated with other error terms including RMTE. Therefore the following equation is used to calculate CSA:
CSA = +/-[(RCSA+RMTE)2 + (RRA)2 + (RTE)2 + (RPE)2 + (RD)2 + (PEA)2]1/2 This calculation takes into consideration the voltage drop between the secondary side of the PT and the DVR. The voltage at the DVR shall be designated as Vr. The voltage at the secondary side of the PT shall be designated as Vs and the voltage at the primary side of the PT shall be designated as Vp.
An iterative method is used to determine the drop out (trip) setpoint (LNTSP), pickup (reset) setpoint (UNTSP) and margin (upper and lower) for the undervoltage function. The goal is to determine a setpoint/reset such that lower margin is 0.2% setting and the upper margin is
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 4 of 23 0.0% setting. The process is as follows (the specific numbers provided below are based on Bus 1F, Table 5):
From DI-4, Table 1a, the upper analytical limit is 92.76% 4160V. This equates to 3858.82V on the primary side (Vp) and 110.25V on the secondary side (Vs) of the transformer. The analytical limit on the secondary side of the transformer is then adjusted to account for a 0.12V voltage drop on the cable between the PT and DVR (assumption 8). Therefore, for the purposes of this calculation the upper analytical limit used for calculating the DVR setpoints is 110.13V (110.25V - 0.12V) at the relay (Vr). From DI-4, Table 1a, the lower analytical limit is 89.57% 4160V. This equates to 3726.11V on the primary side (Vp) and 106.47V on the secondary side (Vs) of the transformer.
A value is chosen for the dropout setpoint (108.13V). Using the formulas from NMP-ES-033-004, the relay uncertainty (LCSA) is determined (1.32V). Then the lower margin (LM) is determined (0.22V). From these derived values, the dropout setpoint at the lower calibration limit is verified to determine that it will support the lower analytical limit without excess margin.
In essence, this means the value for the dropout setpoint minus the relay uncertainty (LCSA) of 1.32V and lower margin (LM) of 0.22V does not fall below the analytical limit. The dropout setpoint at the lower calibration limit is 108.01V (108.13V - 0.12V). Therefore, for bus 1F:
108.01V - 1.32V - 0.22V 106.47V.
After the dropout setpoint at the lower calibration limit is verified, the drift value (LRD) of 0.80V is determined for derivation of the lower Allowable Value. The lower Allowable Value is derived by subtracting the drift from the upper calibration limit of the dropout setpoint. The dropout setpoint at the upper calibration limit is 108.25V (108.13V + 0.12V). This lower Allowable Value (LAV) is 107.45V (108.25V - 0.80V).
Once all the values for the dropout setpoint, lower Allowable Value and the dropout calibration limits are determined, then the pickup or reset setpoint needs to be determined. Design Engineering has requested that the pickup setpoint be as small as possible. For this model of relay, a potentiometer is used to set the difference between the dropout and the pickup setpoints. The smallest difference between the two setpoints is 0.5% of the dropout setting.
Therefore, the minimum pickup setpoint is 100.5% of the dropout nominal setting of 108.13V.
This value equates to 108.68V (108.13
- 100.5%).
At this point, the same process used for determining the lower settings is used to determine the upper settings, adding the UCSA to the upper calibration limit to verify a margin of 0%
against the upper analytical limit at the relay (Vr) and adding URD to the lower calibration limit to determine an upper Allowable Value (UAV) of 109.36V.
Following this process, the calibration limits for bus 1F were determined to be:
108.01V and 108.25V (108.13V +/-0.12V) for the dropout setpoint and 108.56V and 108.80V (108.68V +/-0.12V) for the pickup or reset setpoint.
This methodology provides a margin of 0.20% setting for the dropout function and 0% setting for the pickup (reset) function.
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 5 of 23 An OE search was performed using the following keywords:
Degraded Grid Relay, Harmonic Filter, Harmonic Restraint, ABB 27N, DVR Relay and DVR The results are as follows:
Table 2 - OE Search Results OE Source Potential Project Impact: Relevance/Impact LER 92- On 3/31/92, with the reactor shutdown The setting tolerance used in the 012-00 for routine refueling and maintenance, calculation for the undervoltage (Hatch) the Electrical Maintenance Department function of the relays is assumed found the setpoints of four degraded to be equal to the worst case grid undervoltage relays (EIIS=EB) to reference accuracy of +/-0.12 VAC be below their technical specification (0.1%*120VAC). The drift limits. This condition was identified allowance used is based on plant while performing normal surveillance historical data for ABB 27N activities associated with emergency degraded voltage relays used in a busses three and four. The cause of similar application at a plant with the event is attributed to setpoint drift similar operating conditions and outside of an extremely tight tolerance calibration practices. This should band. The relays were reset to within allow for adequate tolerance their proper tolerance band. between the limiting technical specification NTSPs and AVs.
O&MR 225 During calibration of the 4160V 'D' and The relays used for this application
'E' bus undervoltage relay system, the are the Brown Boveri setpoints for three ITE model 27H recommended 27N models.
relays in 4160V bus '1E' were found out of tolerance. Plants using ITE model 27H relays in their undervoltage protection systems should check them for unacceptable setpoint drift. The supplier, Brown Boveri, advises that ITE model 27N relays should be used for this application.
SEN 272 The bus ground fault protection relay, The settings chosen for the relays 50G/A52-84, actuated and isolated provide sufficent margin power to the bus. The 50G relay betweenthe lower and upper range spuriously operated in response to the limits to avoid spurious actuations.
fault condition; but the cause, although not fully conclusive, is suspected to be high-frequency energy from the ground fault. The high-frequency current flow through the cable capacitance-to-ground reached sufficient magnitudes to actuate the 50G relay. The 50G relay on 1B-04 is a solid-state design and was set at 10 amperes, the lower end of the range (10 to 50 amps) per generic industry guidance. The companion 50G/1A52-58 relay on the other safeguards train, 1B-03, is an older style electromechanical relay and was also
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 6 of 23 OE Source Potential Project Impact: Relevance/Impact set at the low end of the 2.5 to 5 amperes range. The station replaced the 50G/A52-84 train B relay. The settings of both relays were increased to approximately midrange within the acceptable bands. The 50G/A52-84 relay setting was raised from 10 amperes to 30 amperes to reduce the potential for spurious trips. The companion 50G/1A52-58 relay setting on safeguards train 1B-03 was raised to 3 amperes. The solid state design relays are within IEEE generic guidance. No guidance was located for the older electromechanical design relays.
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 7 of 23 4.0 Functional Description The undervoltage relays monitor voltage on 4160 VAC emergency buses 1F, 1G, 2F and 2G (three relays per bus) and actuate when the voltage falls below a predetermined value and remains below this value for a specified amount of time. Actuation of any two out of three relays on the same bus results in an automatic trip of the applicable 4160 VAC preferred power supply breakers, disconnecting the undervoltage (degraded) bus from its offsite preferred power source. The degraded grid voltage and time settings are selected to avoid any nuisance tripping during normal operating conditions while ensuring that the voltage requirements of the safety-related loads are met without exceeding the maximum time delay assumed in the safety analyses.
Figure 2 - Loop Configuration 4160 VAC BUS POTENTIAL TRANSFORMER 4200/120 27 RELAY UV 27-x CONTACT CLOSES ON SUSTAINED*
UNDER VOLTAGE CONDITION
- (AFTER TIME DELAY)
TO AUXILIARY RELAYS ACTUATION LOGIC
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 8 of 23 5.0 Body of Calculation Sensor TPNS Tag #:4160V Bus 1F Relays: 27F3 (3-1), 27F3 (2-3), 27F3 (1-2) 4160V Bus 1G Relays: 27G3 (3-1), 27G3 (2-3), 27G3 (1-2) 4160V Bus 2F Relays: 27F3 (3-1), 27F3 (2-3), 27F3 (1-2) 4160V Bus 2G Relays: 27G3 (3-1), 27G3 (2-3), 27G3 (1-2)
Manufacturer: Asea Brown Boveri (ABB) Model 27N411T5375-HF PM: Once every 18 months Location of Sensor: Auxiliary Building Environmental/Seismic Conditions Normal Design Calibration Temperature 80°F 110°F 70°F Pressure N/A N/A N/A Humidity N/A N/A N/A Assumptions
- 1. Accuracy specifications provided in DI-1 for the undervoltage function are based on the specific operating temperature and control power range applicable to the relays. All accuracies are in % setting and are as follows:
Pickup and dropout settings, repeatability (RRA): +/-0.1% at constant temperature and voltage Pickup and dropout settings, repeatability (TE): +/- 0.75% over a temperature range of 0 to +55°C (32 to 131°F)
Pickup and dropout settings, repeatability (PSE): +/-0.1% over a control power range of 100 to 140 VDC (125VDC nominal)
The vendor specifies that these tolerances may be cumulative. Therefore, these variables will be considered interactive for the purposes of this calculation.
- 2. The relays are solid state devices whose accuracy is not affected by the expected normal auxiliary building pressure and humidity. Therefore, pressure effect (RPE) and humidity effect (HE) are not applicable for the undervoltage function.
RPE = HE = 0.
- 3. Based on section 2.4 of attachment 1 to DI-2, the average temperature for the auxiliary building is 80°F and the design limit of the auxiliary building room ambient temperature is 110°F. The minimum temperature expected in the rooms in which the relays are located is 60°F (Reference DI-16). Therefore, for this application the temperature range is assumed to be 60°F to 110°F.
- 4. The calibration tolerance (RCSA) for the undervoltage function trip and reset is assumed to be equal to the worst case reference accuracy of +/-0.12 VAC (0.1%*120VAC).
- 5. A Fluke 8600A (200 VAC) is assumed to be used to read the voltage input when calibrating the voltage function of the relays. Per DI-2, attachment 2 the accuracy of a Fluke 8600A is 0.2% of input + 0.015% of range. Therefore, instrument calibration accuracy (RMTE) is equal to 0.2% of setting + 0.03 VAC for the undervoltage function.
- 6. The vendor does not specify a drift value for the undervoltage function and no plant historical data is available on the ABB 27N relays. However, there are ABB 27N relays
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 9 of 23 used at the E. I. Hatch Nuclear Plant in a similar application. A drift analysis was performed on the calibration data available from these relays (Attachment A). The various factors that can contribute to variations in the drift performance between the two plants (Hatch and Farley) are compared and evaluated in the following table.
Table 3 - Evaluated Drift Factors Analyzed relays Farley Item Factor Discussion (E.I Hatch) application 1 Calibration NA NA The 27N relays are bistable Span devices.
2 Operating 50 to 105°F 60 to 110°F, The upper limit indicated for this Environment* (Reference DI-9) average application is the design limit.
temperature 80°F Based on the average (Reference temperature of the relays of 80°F, Assumption 3, DI- it is reasonable to assume that 15 & DI-16) the actual temperature in the area will not exceed 105°F. Therefore, for the purpose of this analysis the operating temperature of the analyzed relays envelops the operating temperature of the relays being used for this application and this parameter is not a factor in applying the calculated drift values to the new relays.
3 Calibration Per DI-13 & DI-14 The same or No adverse variation in calibration Practice better practices. Therefore, calibration (Assumption 16 & practice is not a factor in applying
- 17) the calculated drift values to the new relays.
4 Calibration Setpoint/reset Setpoint/reset The undervoltage setpoint/reset Check Point point (nominal) point (nominal) points of the two plants are Voltage: 109 to Voltage: 107.86 to reasonably close (within 3.4%)
111/110 to 112 108.63/108.40 to and therefore, the calibration VAC 109.18 VAC check point difference is not considered a factor in applying (Reference DI-13 (Derived in this the calculated drift values to the
& DI-14) calculation) new relays.
5 Calibration Analyzed for 18 Same (18 month N/A Interval month interval extended to 22.5 month) 6 Human See discussion See discussion The technicians performing the Performance calibrations are assumed to have commensurate skills and experience. Therefore, human performance is not a factor.
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 10 of 23 Analyzed relays Farley Item Factor Discussion (E.I Hatch) application 7 Instrument See discussion See discussion Age-dependent drift is the Age tendency for instrument drift to trend as the instrument ages. A review of the data in Attachment A does not indicate any drift trend as the relay aged. Therefore, instrument age is not a consideration for this application.
- Variations in pressure and humidity are assumed to have no effect on the relay (Assumption 2).
Based on the above evaluation it is reasonable to assume that the undervoltage function drift is equal to the drift value derived in Attachment A for a 22.5 month interval of 0.53%
setting (rounded from 0.5265% setting) with no significant bias. However, for conservatism, a drift value of 0.73% setting shall be used in this calculation.
- 7. Per DI-3, the potential transformers for buses 1F, 1G, 2F, 2G are loaded such that a 0.3% accuracy applies (PEA). Therefore, PEA = 0.3%.
- 8. The maximum voltage drop on the cables from the PTs to the DVRs is calculated in Attachment 7 of DI-4 and 8 as 0.12 V. This value is subtracted from the 120 VAC upper analytical limit (Vs) to determine the actual upper analytical limits at the relays (Vr) and added to the derived upper (reset) relay settings to determine the voltage on the primary side of the transformers (Vp). For conservatism, the voltage drop is not applied to the lower analytical limit.
- 9. The primary to secondary voltage ratio of the transformer is 35:1 (4200VAC:120VAC).
- 10. The test source used in calibrating the relays has less than 0.3% harmonic distortion.
- 11. Radiation and seismic effects (RE and SE) are assumed to be negligible (zero).
- 12. The relays are operated within the vendor specified parameters for temperature (-22 to
+158°F) (Reference DI-1); therefore, temperature effects (TE) for the undervoltage function are as specified in assumption 1.
- 13. The revised voltage analytical limits are based on plant modifications as described in DI-4 and DI-8.
- 14. The control power at the relays is assumed to be within the vendor specified parameters of 100 - 140 VDC. This is based on DI-5, which specifies that the maximum voltage of the battery chargers which supply power to the relays is 132 VDC +/-0.5% (132.66 VDC).
The minimum voltage at the relays occurs when the relays are being powered by the emergency batteries only. DI-6 and DI-7 indicate that this voltage does not fall below the lower limitation (100 VDC) of the relays. Therefore, power supply effects (PSE) for the undervoltage function are as specified in assumption 1.
- 15. The drift uncertainty is time dependent and non-linear and can be extrapolated using the square root of the sum of the squares (SRSS) method per section 6.2.7 of Reference 1.
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 11 of 23
- 16. The maintenance and test equipment (M&TE) used for the calibration of the Farley degraded voltage relays will be equivalent or better than the M&TE equipment used to calibrate the Hatch degraded grid ABB 27N alarm relays identified in Attachment A.
- 17. The calibration methodology used for the Farley degraded voltage relays will be the same methodology used to calibrate the Hatch degraded grid ABB 27N alarm relays (see assumption 6, Attachment A and section 7.5 of DI-13 & DI-14).
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 12 of 23 Buses 1F, 1G, 2F and 2G Undervoltage Function:
Table 4 - Derivation of Uncertainties (Undervoltage Function)
UNCERTAINTY PARAMETER JUSTIFICATION VALUE
(% SETTING)
RRA RRA = +/-0.10% SETTING (Assumption 1) +/-0.10 A Fluke 8600A (200 VAC) will be used to calibrate the undervoltage function of the relays (Assumption 5)
RMTE = +/-0.2% SETTING + 0.03 VAC
+/-0.2 + 3.0 _
RMTE = +/-0.2 + (0.03*100) % SETTING SETTING SETTING
= +/-(0.2 + 3.0 ) % SETTING SETTING RD RD = +/-0.73% SETTING (Assumption 6) +/-0.73 RCSA = +/-0.12 VAC (Assumption 4)
= +/-(0.12 VAC*100) * (% SETTING)
+/- 12.0 _
RCSA SETTING SETTING
= +/- ( 12.0_ ) % SETTING SETTING RTE = +/-((TE + PSE)2 + HE2 + RE2) 1/2 (Assumptions 1, 2, 11)
RTE +/-0.85
= +/-(0.75 + 0.1)2 + 02 + 02)1/2 % SETTING
= +/-0.85% SETTING RPE = 0.0 VAC (Assumption 2)
= +/-(0.0 VAC
- 100) % SETTING RPE +/-0.0 SETTING
= +/-0.0% SETTING Relay Reset Differential RSM = 0.5% SETTING (Reference DI-1) 0.5 (RSM)
Process Allowances:
Process Parameter Tag #:
4160V Bus 1F 4200/120 VAC Transformers:
PT-1, PT-2, PT-3 4160V Bus 1G 4200/120 VAC Transformers:
PT-1, PT-2, PT-3 4160V Bus 2F 4200/120 VAC Transformers:
PT-1, PT-2, PT-3 4160V Bus 2G 4200/120 VAC Transformers:
+/- 36.0 _
PEA PT-1, PT-2, PT-3 SETTING
Description:
primary element Description of PEA: transformer PEA = +/-0.3% full scale (Assumption 7)
= +/- ((0.3
- 120 VAC) * (100) _ % SETTING 100 SETTING
= +/- (36.0) % SETTING SETTING
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 13 of 23 PMA does not apply to transformers. Therefore, PMA =
PMA N/A N/A Bias:
EA The cables, transformers and relays are not exposed to a N/A harsh environment. Therefore, EA = N/A. (Reference DI-15)
Bias No bias terms exist for this loop. Therefore, Bias = N/A N/A Therefore, based on the equation derived in section 3.0:
CSA = +/- [(RCSA+RMTE)2 + (RRA)2 + (RTE)2 + (RPE)2 + (RD)2+ (PEA)2]1/2 2
CSA =+/- 12.0 + 0.2 + 3.0 + (0.10)2+ (0.85)2+ (0)2+ (0.73)2+ 36.0 2 1/2
% SETTING SETTING SETTING SETTING 2 1/2
=+/- 15.0 + 0.2 + 0.01 + 0.7225 + 0.5329 + 1296 % SETTING SETTING (SETTING)2 1/2
=+/- 225 + 6.0 + 0.04 + 0.01 + 0.7225 + 0.5329 + 1296 % SETTING 2 2 (SETTING) SETTING (SETTING) 1/2
=+/- 1521 + 6.0 + 1.3054 % SETTING (SETTING)2 SETTING The Analytical Limits for the undervoltage function of the DVRs are as follows:
Bus 1F Upper Analytical Limit (UAL) = 92.76% of 4160VAC at primary (Reference DI-4, Table 1a)
= (0.9276*4160) VAC at primary
= 3858.82 VAC at primary (Vp)
= (0.9276*4160)/35 - 0.12 VAC at relay (Assumption 8)
= 110.13 VAC at relay (Vr)
Lower Analytical Limit (LAL) = 89.57% of 4160VAC at primary (Reference DI-4, Table 1a)
= (0.8957*4160) VAC at primary
= 3726.11 VAC at primary (Vp)
= (0.8957*4160)/35 at secondary/relay (Assumption 8)
= 106.47 VAC at secondary/relay (Vs,Vr)
Bus 1G Upper Analytical Limit (UAL) = 92.53% of 4160VAC at primary (Reference DI-4, Table 1a)
= (0.9253*4160) VAC at primary
= 3849.25 VAC at primary (Vp)
= (0.9253*4160)/35 - 0.12 VAC at relay (Assumption 8)
= 109.85 VAC at relay (Vr)
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 14 of 23 Lower Analytical Limit (LAL) = 89.35% of 4160VAC at primary (Reference DI-4, Table 1a)
= (0.8935*4160) VAC at primary
= 3716.96 VAC at primary (Vp)
= (0.8935*4160)/35 at secondary/relay (Assumption 8)
= 106.20 VAC at secondary/relay (Vs,Vr)
Bus 2F Upper Analytical Limit (UAL) = 92.67% of 4160VAC at primary (Reference DI-8, Table 1a)
= (0.9267*4160) VAC at primary
= 3855.07 VAC at primary (Vp)
= (0.9267*4160)/35 - 0.12 VAC at relay (Assumption 8)
= 110.02 VAC at relay (Vr)
Lower Analytical Limit (LAL) = 89.48% of 4160VAC at primary (Reference DI-8, Table 1a)
= (0.8948*4160) VAC at primary
= 3722.37 VAC at primary (Vp)
= (0.8948*4160)/35 at secondary/relay (Assumption 8)
= 106.36 VAC at secondary/relay (Vs,Vr)
Bus 2G Upper Analytical Limit (UAL) = 93.19% of 4160VAC at primary (Reference DI-8, Table 1a)
= (0.9319*4160) VAC at primary
= 3876.70 VAC at primary (Vp)
= (0.9319*4160)/35 - 0.12 VAC at relay (Assumption 8)
= 110.64 VAC at relay (Vr)
Lower Analytical Limit (LAL) = 89.99% of 4160VAC at primary (Reference DI-8, Table 1a)
= (0.8999*4160) VAC at primary
= 3743.58 VAC at primary (Vp)
= (0.8999*4160)/35 at secondary/relay (Assumption 8)
= 106.96 VAC at secondary/relay (Vs,Vr)
The values calculated in the following tables are based on the methodology outlined in DI-2, section A.3.45 and presented as shown in DI-2, Appendix B page 52.
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 15 of 23 Table 5 - Bus 1F Calculation of Limiting Values (Undervoltage Function)
Reset Point at Upper Reset Point at Lower At Reset Point Calibration Limit Calibration Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
Upper Analytical Limit (UAL) **(Vr) 110.13 91.78 110.13 91.78 110.13 91.78 Upper Margin (UM) 0.12 0.10 0.00 0.00 0.24 0.20 Adjusted UAL (UAL-UM) 110.01 91.68 110.13 91.78 109.89 91.58 Upper Allowable Value (UAV) =
UCLL + URD 109.36 91.13 URD 0.73 0.80 0.67
[1521/SETTING2 +
UCSA 6.0/SETTING
+1.3054]1/2 1.33 1.11 1.33 1.11 1.33 1.11 UCLH (Upper Calibration Limit -
High) TS RSP = UNTSP + RCSA 108.80* 90.67 RCSA 12.0/SETTING 0.12 0.10 Upper Nominal Reset Point (UNTSP) pickup 108.68* 90.57 RCSA 12.0/SETTING 0.12 0.10 UCLL (Upper Calibration Limit -
Low) = UNTSP - RCSA 108.56* 90.47 At Setpoint (Proposed Relay Setpoint at Upper Calibration Setpoint at Lower Calibration Setting) Limit Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
LCLH (Lower Calibration Limit -
High) = LNTSP + RCSA 108.25* 90.21 RCSA 12.0/SETTING 0.12 0.10 Lower Nominal Trip Setpoint (LNTSP) dropout 108.13* 90.11 RCSA 12.0/SETTING 0.12 0.10 LCLL (Lower Calibration Limit -
Low) TS SP = LNTSP - RCSA 108.01* 90.01
[1521/SETTING2 +
LCSA 6.0/SETTING
+1.3054]1/2 1.33 1.11 1.33 1.11 1.32 1.10 LRD 0.73 0.80 0.67 Lower Allowable Value (LAV) =
setting value - LRD 107.45 89.54 Adjusted LAL (LAL + LM) 106.80 89.00 106.92 89.10 106.69 88.91 Lower Margin (LM) 0.33 0.27 0.45 0.38 0.22 0.18 Lower Analytical Limit (LAL) (Vs) 106.47 88.73 106.47 88.73 106.47 88.73
- Indicates setting value used to calculate AV, RCSA and CSA for each section outlined in the Table
- Adjusted for voltage drop of 0.12V at secondary (Assumption 8)
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 16 of 23 Bus 1F Undervoltage Function:
Based on Table 5 the limiting settings for the undervoltage function for Bus 1F are as follows:
Upper Allowable Value (reset point) = 109.36 VAC (91.13% 120VAC) increasing at relay (Vr)
= (109.36 VAC + 0.12)
- 35 = 3831.80 VAC increasing at primary (Assumption 8) (Vp)
= (3831.80/4160)
- 100% = 92.11% 4160VAC increasing at primary Nominal Reset point = 108.68 VAC (90.57% 120VAC) increasing at relay (Vr)
= (108.68 VAC + 0.12)
- 35 = 3808.00 VAC increasing at primary (Assumption 8) (Vp)
= (3808.00/4160)
- 100% = 91.54% 4160VAC increasing at primary Nominal Setpoint = 108.13 VAC (90.11% 120VAC) decreasing at secondary (Vs, Vr)
= 108.13 VAC
- 35 = 3784.55 VAC decreasing at primary (Vp)
= (3784.55/4160)
- 100% = 90.97% 4160VAC decreasing at primary Lower Allowable Value (setpoint) = 107.45 VAC (89.54% 120VAC) decreasing at secondary (Vs, Vr)
= 107.45 VAC
- 35 = 3760.75 VAC decreasing at primary (Vp)
= (3760.75/4160)
- 100% = 90.40% 4160VAC decreasing at primary This allows for a minimum margin of 0.22 VAC (0.20% of the lower calibration limit of 108.01 VAC).
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 17 of 23 Table 6 - Bus 1G Calculation of Limiting Values (Undervoltage Function)
Reset Point at Upper Reset Point at Lower At Reset Point Calibration Limit Calibration Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
Upper Analytical Limit (UAL) ** (Vr) 109.85 91.54 109.85 91.54 109.85 91.54 Upper Margin (UM) 0.12 0.10 0.00 0.00 0.24 0.20 Adjusted UAL (UAL-UM) 109.73 91.44 109.85 91.54 109.61 91.34 Upper Allowable Value (UAV) =
UCLL + URD 109.08 90.90 URD 0.73 0.80 0.67
[1521/SETTING2 +
UCSA 6.0/SETTING
+1.3054]1/2 1.33 1.11 1.33 1.11 1.33 1.11 UCLH (Upper Calibration Limit -
High) TS RSP = UNTSP + RCSA 108.52* 90.43 RCSA 12.0/SETTING 0.12 0.10 Upper Nominal Reset Point (UNTSP) pickup 108.40* 90.33 RCSA 12.0/SETTING 0.12 0.10 UCLL (Upper Calibration Limit -
Low) = UNTSP - RCSA 108.28* 90.23 At Setpoint (Proposed Relay Setpoint at Upper Calibration Setpoint at Lower Calibration Setting) Limit Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
LCLH (Lower Calibration Limit -
High) = LNTSP + RCSA 107.98* 89.98 RCSA 12.0/SETTING 0.12 0.10 Lower Nominal Trip Setpoint (LNTSP) dropout 107.86* 89.88 RCSA 12.0/SETTING 0.12 0.10 LCLL (Lower Calibration Limit -
Low) TS SP = LNTSP - RCSA 107.74* 89.78
[1521/SETTING2 +
LCSA 6.0/SETTING
+1.3054]1/2 1.32 1.10 1.32 1.10 1.32 1.10 LRD 0.73 0.79 0.66 Lower Allowable Value (LAV) =
setting value - LRD 107.19 89.33 Adjusted LAL (LAL + LM) 106.54 88.78 106.66 88.88 106.42 88.68 Lower Margin (LM) 0.34 0.28 0.46 0.38 0.22 0.18 Lower Analytical Limit (LAL) (Vs) 106.20 88.50 106.20 88.50 106.20 88.50
- Indicates setting value used to calculate AV, RCSA and CSA for each section outlined in the Table
- Adjusted for voltage drop of 0.12V at secondary (Assumption 8)
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 18 of 23 Bus 1G Undervoltage Function:
Based on Table 6 the limiting settings for the undervoltage function for Bus 1G are as follows:
Upper Allowable Value (reset point) = 109.08 VAC (90.90% 120VAC) increasing at relay (Vr)
= (109.08 VAC + 0.12)
- 35 = 3822.00 VAC increasing at primary (Assumption 8) (Vp)
= (3822.00/4160)
- 100% = 91.88% 4160VAC increasing at primary Reset point = 108.40 VAC (90.33% 120VAC) increasing at relay (Vr)
= (108.40 VAC + 0.12)
- 35 = 3798.20 VAC increasing at primary (Assumption 8) (Vp)
= (3798.20/4160)
- 100% = 91.30% 4160VAC increasing at primary Setpoint = 107.86 VAC ((89.88% 120VAC) decreasing at secondary (Vs, Vr)
= 107.86 VAC
- 35 = 3775.10 VAC decreasing at primary (Vp)
= (3775.10/4160)
- 100% = 90.75% 4160VAC decreasing at primary Lower Allowable Value (setpoint) = 107.19 VAC (89.33% 120VAC) decreasing at secondary (Vs, Vr)
= 107.19 VAC
- 35 = 3751.65 VAC decreasing at primary (Vp)
= (3751.65/4160)
- 100% = 90.18% 4160VAC decreasing at primary This allows for a minimum margin of 0.22 VAC (0.20% of the lower calibration limit of 107.74 VAC).
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 19 of 23 Table 7- Bus 2F Calculation of Limiting Values (Undervoltage Function)
Reset Point at Upper Reset Point at Lower At Reset Point Calibration Limit Calibration Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
Upper Analytical Limit (UAL) ** (Vr) 110.02 91.68 110.02 91.68 110.02 91.68 Upper Margin (UM) 0.12 0.10 0.00 0.00 0.24 0.20 Adjusted UAL (UAL-UM) 109.90 91.58 110.02 91.68 109.78 91.48 Upper Allowable Value (UAV) =
UCLL + URD 109.25 91.04 URD 0.73 0.80 0.67
[1521/SETTING2 +
UCSA 6.0/SETTING
+1.3054]1/2 1.33 1.11 1.33 1.11 1.33 1.11 UCLH (Upper Calibration Limit -
High) TS RSP = UNTSP + RCSA 108.69* 90.58 RCSA 12.0/SETTING 0.12 0.10 Upper Nominal Reset Point (UNTSP) pickup 108.57* 90.48 RCSA 12.0/SETTING 0.12 0.10 UCLL (Upper Calibration Limit -
Low) = UNTSP - RCSA 108.45* 90.38 At Setpoint (Proposed Relay Setpoint at Upper Calibration Setpoint at Lower Calibration Setting) Limit Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
LCLH (Lower Calibration Limit -
High) = LNTSP + RCSA 108.14* 90.12 RCSA 12.0/SETTING 0.12 0.10 Lower Nominal Trip Setpoint (LNTSP) dropout 108.02* 90.02 RCSA 12.0/SETTING 0.12 0.10 LCLL (Lower Calibration Limit -
Low) TS SP = LNTSP - RCSA 107.90* 89.92
[1521/SETTING2 +
LCSA 6.0/SETTING
+1.3054]1/2 1.32 1.10 1.33 1.11 1.32 1.10 LRD 0.73 0.79 0.66 0.79 0.66 0.79 0.66 Lower Allowable Value (LAV) =
setting value - LRD 107.35 89.46 Adjusted LAL (LAL + LM) 106.70 88.92 106.81 89.01 106.58 88.82 Lower Margin (LM) 0.34 0.28 0.45 0.38 0.22 0.18 Lower Analytical Limit (LAL) (Vs) 106.36 88.63 106.36 88.63 106.36 88.63
- Indicates setting value used to calculate AV, RCSA and CSA for each section outlined in the Table
- Adjusted for voltage drop of 0.12V at secondary (Assumption 8)
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 20 of 23 Bus 2F Undervoltage Function:
Upper Allowable Value (reset point) = 109.25 VAC (91.04% 120VAC) increasing at relay (Vr)
= (109.25 VAC + 0.12)
- 35 = 3827.95 VAC increasing at primary (Assumption 8) (Vp)
= (3827.95/4160)
- 100% = 92.02% 4160VAC increasing at primary Reset point = 108.57 VAC (90.48% 120VAC) increasing at relay (Vr)
= (108.57 VAC+ 0.12)
- 35 = 3804.15 VAC increasing at primary (Assumption 8) (Vp)
= (3804.15/4160)
- 100% = 91.45% 4160VAC increasing at primary Setpoint = 108.02 VAC (90.02% 120VAC) decreasing at secondary (Vs, Vr)
= 108.02 VAC
- 35 = 3780.70 VAC decreasing at primary (Vp)
= (3780.70/4160)
- 100% = 90.88% 4160VAC decreasing at primary Lower Allowable Value (setpoint) = 107.35 VAC (89.46% 120VAC) decreasing at secondary (Vs, Vr)
= 107.35 VAC
- 35 = 3757.25 VAC decreasing at primary (Vp)
= (3757.25/4160)
- 100% = 90.32% 4160VAC decreasing at primary This allows for a minimum margin of 0.22 VAC (0.20% of the lower calibration limit of 107.90 VAC).
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 21 of 23 Table 8 - Bus 2G Calculation of Limiting Values (Undervoltage Function)
Reset Point at Upper Reset Point at Lower At Reset Point Calibration Limit Calibration Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
Upper Analytical Limit (UAL) ** (Vr) 110.64 92.20 110.64 92.20 110.64 92.20 Upper Margin (UM) 0.12 0.10 0.00 0.00 0.24 0.20 Adjusted UAL (UAL-UM) 110.52 92.10 110.64 92.20 110.40 92.00 Upper Allowable Value (UAV) =
UCLL + URD 109.86 91.55 URD 0.73 0.80 0.67
[1521/SETTING2 +
UCSA 6.0/SETTING
+1.3054]1/2 1.34 1.12 1.34 1.12 1.34 1.12 UCLH (Upper Calibration Limit -
High) TS RSP = UNTSP + RCSA 109.30* 91.08 RCSA 12.0/SETTING 0.12 0.10 Upper Nominal Reset Point (UNTSP) pickup 109.18* 90.98 RCSA 12.0/SETTING 0.12 0.10 UCLL (Upper Calibration Limit -
Low) = UNTSP - RCSA 109.06* 90.88 At Setpoint (Proposed Relay Setpoint at Upper Calibration Setpoint at Lower Calibration Setting) Limit Limit Engineering Engineering Engineering Parameter % Setting %120VAC %120VAC %120VAC Units (VAC) Units (VAC) Units (VAC)
LCLH (Lower Calibration Limit -
High) = LNTSP + RCSA 108.75* 90.63 RCSA 12.0/SETTING 0.12 0.10 Lower Nominal Trip Setpoint (LNTSP) dropout 108.63* 90.53 RCSA 12.0/SETTING 0.12 0.10 LCLL (Lower Calibration Limit -
Low) TS SP = LNTSP - RCSA 108.51* 90.43
[1521/SETTING2 +
LCSA 6.0/SETTING
+1.3054]1/2 1.33 1.11 1.33 1.11 1.33 1.11 LRD 0.73 0.80 0.67 0.80 0.67 Lower Allowable Value (LAV) =
setting value - LRD 107.95 89.96 Adjusted LAL (LAL + LM) 107.30 89.42 107.42 89.52 107.18 89.32 Lower Margin (LM) 0.34 0.28 0.46 0.38 0.22 0.18 Lower Analytical Limit (LAL) (Vs) 106.96 89.13 106.96 89.13 106.96 89.13
- Indicates setting value used to calculate AV, RCSA and CSA for each section outlined in the Table
- Adjusted for voltage drop of 0.12V at secondary (Assumption 8)
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 22 of 23 Bus 2G Undervoltage Function:
Upper Allowable Value (reset point) = 109.86 VAC (91.55% 120VAC) increasing at relay (Vr)
= 109.86 VAC + 0.12)
- 35 = 3849.30 VAC increasing at primary (Assumption 8) (Vp)
= (3849.30/4160)
- 100% = 92.53% 4160VAC increasing at primary Reset point = 109.18 VAC (90.98% 120VAC) increasing at relay (Vr)
= 109.18 VAC + 0.12)
- 35 = 3825.50 VAC increasing at primary (Assumption 8) (Vp)
= (3825.50/4160)
- 100% = 91.96% 4160VAC increasing at primary Setpoint = 108.63 VAC (90.53% 120VAC) decreasing at secondary (Vs, Vr)
= 108.63 VAC
- 35 = 3802.05 VAC decreasing at primary (Vp)
= (3802.05/4160)
- 100% = 91.40% 4160VAC decreasing at primary Lower Allowable Value (setpoint) = 107.95 VAC (89.96% 120VAC) decreasing at secondary (Vs, Vr)
= 107.95 VAC
- 35 = 3778.25 VAC decreasing at primary (Vp)
= (3778.25/4160)
- 100% = 90.82% 4160VAC decreasing at primary This allows for a minimum margin of 0.22 VAC (0.20% of the lower calibration limit of 108.51 VAC)
Plant: Calculation Number: Sheet:
Farley U1 & U2 SJ-SNC529029-001 Sheet 23 of 23 Design Inputs (DI):
(1) IB 7.4.1.7-7, ABB Instructions Single Phase Voltage Relays (Attachment B)
(2) NMP-ES-033-004, Version 6.0, Setpoint Control Program Farley Setpoint Uncertainty Methodology and Scaling Instructions (3) Calculation SE-92-2204-2-PE, Version 3.0, Analysis of P.T. Accuracy for 4kV Buses 1F, 1G, 2F and 2G (4) Calculation SE-SNC529029-001, Version 1.0, Unit 1 Minimum Expected Voltage Study (5) Calculation E-035.01.C, Version 2.0, Setting of Protective Relays for FNP Unit 1 125VDC Auxiliary Power System (6) Calculation E-095, Version 13.0, Auxiliary Building Battery Capacity and Voltage Evaluation (7) Calculation E-098, Version 5.0, Criteria For Circuit Lengths For 125V DC Control Circuits (8) Calculation SE-SNC529029-002, Version 1.0, Unit 2 Minimum Expected Voltage Study (9) Edwin I. Hatch Nuclear Plant Unit No 1 & 2 Document H12619, Version 12.0, Architectural - Generator Building Heating & Ventilating General Arrangement &
Parts Numbers (10) EPRI TR-103335, Guidelines for Instrument Calibration Extension / Reduction -
Revision 1 (11) NUREG-1475, Revision 1, Applying Statistics (12) ANSI N15.15-1974, Assessment Of The Assumption Of Normality (Employing Individual Observed Values)
(13) Southern Nuclear Plant E. I. Hatch Surveillance Procedure, 57SV-S32-002-1, Version 11.0, Emergency Buses 1E, 1F, and 1G Undervoltage Relay Instrument FT&C (14) Southern Nuclear Plant E. I. Hatch Surveillance Procedure, 57SV-S32-002-2, Version 13.2, Emergency Buses 2E, 2F, and 2G Undervoltage Relay FT&C (15) FNP FSAR Section 3.11.2.2, Equipment Outside Containment, Rev 21, dated 5/08 (16) FNP FSAR Section 9.4.2.1.1, Nonradioactive Area Heating and Ventilating System, Rev 24, dated 10/12
References:
(1) ISA-RP67.04.02-2000, Recommended Practice, Methodologies for the Determination of Setpoints for Nuclear Safety-Related Instrumentation