ET 19-0020, Supplemental Response to Request for Additional Information Revision to Technical Specification 3.3.5, Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation
| ML19326A162 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 11/13/2019 |
| From: | Shawn Smith Wolf Creek |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| ET 19-0020 | |
| Download: ML19326A162 (12) | |
Text
!
FCREEK Stephen L Smith Vtce President Engmeenng November 13, 2019 ET 19-0020 U.S. Nuclear Regulatory Commission A TIN: Document Control Desk Washington, DC 20555
References:
- 1)
Letter ET 19-0002, dated March 18, 2019, from S. L. Smith, WCNOC, to USNRC
Subject:
- 2)
Letter dated August 12, 2019, from B. K. Singal, USNRC, to S. L.
Smith, WCNOC, "Request for Additional Information Re: Revision to Technical Specification 3.3.5, 'Loss of Power (LOP) Diesel Generator (DG) Start lnstn1_mentation' Wolf Creek Generating Station (EPID No.
- 3)
Letter ET 19-0019, dated September 10, 2019, from S. L. Smith, WCNOC, to USNRC Docket No. 50-482:
Supplemental Response to Request for Additional Information "Revision to Technical Specification 3.3.5, Loss of Power (LOP) Diesel Generator (DG) Start lnstrumentationn To Whom It May Concern:
Reference 1 provided a Wolf Creek Nuclear Operating Corporation (WCNOC) license amendment request (LAR) to revise the Wolf Creek Generating Station (WCGS) Technical Specifications (TS).
The proposed amendment would revise TS Surveillance Requirement (SR) 3.3.5.3 regarding the degraded voltage and loss of voltage relays Allowable Values, nominal Trip Setpoints and time delays based on analysis utilizing the guidance in Regulatory Issue Summary (RIS) 2011-12, Revision 1, "Adequacy of Station Electric Distribution System Voltages." Reference 2 provided a request for additional information (RAI) related to the LAR.
Reference 3 provided the responses to the request in Reference 2, excluding RAI Question 4.
WCNOC personnel agreed to provide the response to RAI Question 4 by November 15, 2019.
On October 8, 2019, a teleconference was conducted between Nuclear Regulatory Commission (NRC) staff and WCNOC personnel. The purpose of the teleconference was to discuss several of the responses provided in Reference 3. The NRC staff indicated that several of the RAI responses required clarification. The attachment to this submittal contains the response to RAI P.O. Box 411 / Burlington, KS 66839 / Phone: (620) 364-8831 An Equal Opportunity Employer M/F/HC.,tVET ADD l f}~l
ET 19-0020 Page 2 of 3 Question 4, as well as the clarifying information for the other RAI responses requested by the NRC staff.
The information provided in this submittal does not expand the scope of the application and does not impact the significance hazards consideration determination presented in Reference
- 1. In accordance with 10 CFR 50.91, "Notice for public comment; State consultation," a copy of this submittal is being provided to the designated Kansas State official.
This letter contains no commitments. If you have any questions concerning this matter, please contact me at (620) 364-4093, or Ron Benham at (620) 364-4204.
Stephen L. Smith SLS/rlt
Attachment:
Supplemental Response to Request for Additional Information "Revision to Technical Specification 3.3.5, Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation" cc S. A. Morris (NRC), w/a N. O'Keefe (NRC), w/a B. K. Singal (NRC), w/a K. S. Steves (KDHE), w/a Senior Resident Inspector (NRC), w/a
ET 19-0020 Page 3 of 3 STATE OF KANSAS
)
) 55 COUNTY OF COFFEY )
Stephen L. Smith, of lawful age, being first duly sworn upon oath says that he is Vice President Engineering of Wolf Creek Nuclear Operating Corporation; that he has read the foregoing document and knows the contents thereof; that he has executed the same for and on behalf of said Corporation with full power and authority to do so; and that the facts therein stated are true and correct to the best of his knowledge, information and belief.
By........,._~-"'-------"-4------
Stephen L. Smith Vice President Engineering SUBSCRIBED and sworn to before me this /JH{ay of nouembe,-
I 2019.
RHONDA L. TIEMEYER Nota,y Public, State of Kansas Appointment Qhamdrt cf 'Ji~
Notary Public
(/
Expiration DateJ~ J / 1 J.iJ :Jc:J__
Attachment to ET 19-0020 Page 1 of 9 Supplemental Response to Request for Additional Information "Revision to Technical Specification 3.3.5, Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation" Reference 1 provided a Wolf Creek Nuclear Operating Corporation (WCNOC) license amendment request (LAR) to revise Wotf Creek Generating Station (WCGS) Technical Specifications (TS). The proposed amendment would revise TS Surveillance Requirement (SR) 3.3.5.3 regarding the degraded voltage (DV) and loss of voltage (LOV) relays Allowable Values, nominal Trip Setpoints and time delays based on analysis utilizing the guidance in Regulatory Issue Summary (RIS) 2011-12, Revision 1, "Adequacy of Station Electric Distribution System Voltages. D Reference 2 provided a request for additional information (RAI) related to the application.
On October 8, 2019, a teleconference between the NRC staff and WCNOC determined clarification was needed for several responses provided in Reference 3.
Reference 4 was provided as clarification to previously provided responses. WCNOC is supplying supplemental responses to clarify the responses to RAI Questions 3, 6, and 9 provided in Reference 3. A revised response is being provided for RAI Question 8 which was initially provided in Reference
- 3. The response to RAI Question 4 (Reference 2) is also being provided. The specific Nuclear Regulatory Commission (NRC) requests are provided in italics.
NRC Clarification Request Regarding RAI No. 3 In its response to RA/ No. 3, in letter dated September 10, 2019, it is proposed to revise SR 3.3:5.3.b to retain the time d~/ay associated without a safety injection signal (SIS) present but change the nominal time delay from 119 seconds to 56 seconds. However, the supplement does not contain a justification for changing the nominal time delay.
What is the justification for change of the nominal time delay from 119 seconds to 56 seconds, and summary of any associated analysis supporting time delay of nominal 56 seconds (+8.5 sec, -7.6 sec) without an SIS present.
WCNOC Supplemental Response The existing total time delay, 119 sec for the non-SIS condition, is the sum of the degraded voltage (DV) relay timer (8 sec, +0.5, -0.6) and the second delay timer (111 +/-11 sec) which are in series. The second delay timer is bypassed in case of a safety injection signal (SIS).
The first time delay internal to the load shedder and emergency load sequencer (LSELS) rack was chosen to be 8 seconds. This time delay was chosen such that large motor starts (and voltage dips) would not falsely arm the DV circuitry to ensure buses are not falsely tripped and nuisance alarms are not received in the control room on large motor starts, it is necessary to select time delays to block the degraded voltage relay (DVR) actuation and disconnection of the offsite power supply during those periods. From Calculation XX-E-006 (Reference 5, page 20 of 139) recovery voltage summary table, Class 1 E motors fed from the safety-related 4.16 kV buses are required to start in 4 seconds or less to avoid overlapping the load sequencer 5-second step times. Therefore, the first time delay internal to LSELS was chosen to be slightly longer than the maximum starting time to ensure the system is not falsely challenged.
The second time delay was chosen to be 111 seconds to allow an additional period for the operator to restore bus voltage prior to tripping the bus feeder breaker(s) and transferring loads
Attachment to ET 19-0020 Page 2 of 9 to the emergency diesel generator (EOG). Per discussion with Operations, if a DV condition was detected, 111 seconds would not be enough time to perform any manual action required in that situation. Therefore, the non-accident time delay was reduced from 111 sec to 48 sec to ensure that the normally running safety-related equipment is subjected to less heat as a result of sustained system DV condition without an SIS.
The maximum 48 sec time delay for the second timer was selected to ensure no operating safety-related load protective devices trip, whereas the minimum time delay is dictated by the startup time of the reactor coolant pump (RCP) motor which is determined to be the longest startup time in the system.
An RCP start is the worst-case motor start.
Per XX-E-006 (Reference 6, page 49 of 100), Revision 08, with 80% voltage at the motor terminals, the RCP will start in approximately 31 seconds. Therefore, 31 seconds will be used as the minimum acceptable time delay for the DVR without SIS.
The steps for setting the relay are described in the figure below:
Margin
--.-+--~------ Analytical Limit (AI.1Wlx)
---+-1-~-------Allowable Value (AV) in Teclmical SpecifJCatioos SR 3.3.5.3 Total Loop Error (11.,E+)
Total Measurable Uncertainties
(+)
ST Allowable setting tolerance
ATSP ST Min. ATSP (ATSPmin)
Total Loop Error (11.,E)
___,.--.-Aualytical Limit (ALnu.J t== 0 seconds Start of Event
(+)
Largest Mote.- Startup Time/Sequencer Time Per section 4.7.6.2 of XX-E-009-001-CN006 (Reference 6):
RCP Motor accelerating time at 80% rated voltage equals 31 seconds Additional margin of 10 seconds added Drift = +5.85/-4. 77seconds Setting tolerance of 2.01 seconds Total equals 47.78 seconds, Actual Trip Setpoint (ATSP) rounded up to 48 seconds.
Nominal Trip Setpoint (NTSP) = ATSP + setting tolerance= 50.01 sec Allowable Value (AV)= NTSP +Drift= 55.86 sec rounded up to 56 sec
Attachment to ET 19-0020 Page 3 of 9 The new total time delay 56 (+8.5, -7.6) sec for the non-SIS condition is the sum of the DVR timer (8 sec, +0.5, -0.6) and the second delay timer (48 sec, +8, -7 sec).
The overcurrent protective device settings for the safety-related motors that are running during normal operation were evaluated to demonstrate that the overcurrent protective devices will not trip when the bus voltage is at the LOV relay lower analytical limit (ALmm) for the DV non-accident time delay (upper analytical limit ALmax), plus the additional time needed to accelerate the motor on the EOG. The upper analytical limit for the DV non-accident time delay is 64.5 seconds (DV maximum allowable time delay of 56 (rounded from 55.86) seconds plus DVR timer maximum allowable time delay of 8.5 seconds). For conservatism, the maximum time delay is considered to be 64.5 seconds for this analysis (Reference 6, attachment C4, C5).
NRC RAJ Question No. 4 In the LAR, Attachment I, Page 5, the licensee stated:
A review of the current licensing basis calculation of record detennined that the existing TS SR 3.3.5.3 allowable values, nominal Trip Setpoints, and time delays are acceptable and that the Class 1 E electrical equipment is OPERABLE.
However, WCNOC has detennined that current licensing basis margins do not provide sufficient margin for long tenn operation.
Please provide clarification (with an example) regarding the statement that the current licensing basis margins do not provide sufficient margin for long tenn operation.
WCNOC Response WCNOC perfom'ied a calculation, "DVR Interim Analysis, D to confirm the results of the preliminary analysis. The DVR Interim Analysis calculation verified the existing TS SR 3.3.5.3 allowable values, nominal Trip Setpoints, and time delays are acceptable and that the Class 1 E electrical equipment is OPERABLE. The DVR -Interim Analysis calculation shows that safety-related equipment has adequate voltage for starting and running at the existing TS SR 3.3.5.3 DV allowable value. This analysis also shows that the safety-related motors that are operating during normal operation will not stall if the safety-related 4.16 kV bus voltages decrease to the existing TS SR 3.3.5.3 LOV allowable value.
The current licensing basis margins do provide sufficient operational margin; however, they do not allow for additional load growth.
- 1.
Equipment Run Voltages at DVR Allowable Value at existing DVR values Min Accept Running Voltage Running Running of Voltage Vterminal 460V Margin Terminal
(%
(%
(%
Bus ID Description Bus ID Type Rated)
Rated)
Rated)
DCGG02A Emergency Exhaust Fan A MCC Induction 90.25%
90%
NG03C 0.25%
Attachment to ET 19-0020 Page 4 of 9 DCGK03B Control Rom Filtration Fan B DCGM01A DG Bldg Suooly Fan A DCGM018 DG Bldg Supply Fan B DPEC01A Spent Fuel Pool Cooling Pump A DPJE01B Emergency Fuel Oil Transfer Pump B DPKJ03B EOG Lube Oil/Keep Warm Pump B
DSGF02B AFWP Room Cooler B DSGG04A*
Fuel Pool Pump Room Cooler A DSGG04B Fuel Pool Pump Room Cooler B DSGL11B CCWP Room Cooler DSGN018 Containment Cooler B - Slow SLOW DSGN01D Containment Cooler D - Slow SLOW EGG10A Emergency Exhaust Heating Coil EGG10B Emergency Exhaust Heating Coil XPN07A Non-Class 1 E Instr AC Power XPN08A Non-Class 1 E Instr AC Pqwer MCC Induction 90.76%
90%
NG04C 0.76%
NG03 Induction 90.66%
90%
0.66%
NG04 Induction 90.68%*
90%
0.68%
NG01 Induction 90.92%
90%
0.92%
MCC Induction 90.96%
90%
0.96%
NG04D MCC Induction 90.89%
90%
0.89%
NG04D MCC Induction 90.62%
90%
0.62%
NG04C MCC Induction 89.96%
90%
-0.04%
NG03C MCC Induction 90.30%
90%
0.30%
NG04C MCC Induction 90.44%
90%
0.44%
NG04C NG02 Induction 90.97%
90%
0.97%
NG04 Induction 90.24%
90%
0.24%
MCC Static 90.56%
90%
0.56%
NG03C MCC Static 90.12%
90%
0.12%
NG04C MCC Static 90.88%
. 90%
0.88%
NG01B MCC Static 90.39%
90%
0.39%
NG02B Note*: Fuel Pool Pump Room Cooler A, Equipment ID DSGG04A, has steady state voltage of 89.96% of rated voltage at the DVR TS allowable value of 105.9V. This is acceptable because the motor is only loaded to 85% of rated horsepower, and the calculated motor running current is only 3.3% greater than rated full load current. In addition, the calculated stall voltage is less than 50% rated (Reference 7, Att. C2, page 4). Thus, the motor will not stall or experience overheating with the exception of long-term motor degradation, which does not impact the mission time of the component.
- 2.
Class 1 E Bus Voltages at DVR Allowable Value at existing DVR values Min Accept Voltage Voltage Margin Bus ID NominalV Tvoe
% Rated
% Rated
% Rated MCC 480 Load 88.48 88.17 0.31 NG01A MCC 480 Load 88.15 88.17
-0.02 NG01B MCC 480 Load 87.95 88.17
-0.22 NG01T MCC 480 Load 88.54 88.17 0.37 NG02A
Attachment to ET 19-0020 Page 5 of 9 MCC 480 NG02B MCC 480 NG02T MCC 480 NG03C MCC 480 NG03D MCC 0.48 NG03T MCC 0.48 NG04C MCC 0.48 NG04D MCC 0.48 NG04T Load 87.89 88.17
-0.28 Load 87.78 88.17
-0.39 Load 87.90 88.17
-0.27 Load 88.03 88.17
-0.14 Load 87.53 88.17
-0.64 Load 87.56 88.17
-0.61 Load 87.68 88.17
-0.49 Load 86.89 88.17
-1.28 Note: At the current DVR TS allowable value of 105.9V, 480V motor control centers (MCCs)
NG01A, NG02A, NGOSE, and NG06E have adequate voltage to ensure proper operation of the control circuits for the 480V connected loads. However, the voltages at MCC's NG01B, NG01T, NG02B, NG02T, NG03C, NG03D, NG03T, NG04C, NG04D, and NG04T were slightly below the minimum acceptance criteria. The MCC voltages were analyzed as acceptable in Section 4.2.1.1. (Reference 7) where a load flow analysis at the DVR TS allowable value of 105.9V was performed to verify the following:
- a. The operating (running) voltages of all required Class 1 E loads meet design requirements.
- 3.
Equipment Run and Stall Voltage at LOV Relay Allowable Value at existing DVR values Stall Voltage Stall Margin Voltage BOT Based Based on BOT Margin Load on 100%
100%
Based Based on Bus ID Description BHP FLT FLT*
on BHP BHP DPEF01A Essential Service 1737.925 200.00%
0.25%
201.39%
0.49%
Water Pump A DPEF01B Essential Service 1737.925 200.00%
0.24%
201.39%
0.48%
Water Pump B DCGN03A FAST H2 Mixing Fan A 26.6 219.00%
0.25%
411.65%
18.53%
DCGN03B FAST H2 Mixing Fan B 26.6 219.00%
-0.03%
411.65%
18.25%
DCGN03C FAST H2 Mixing Fan C 26.6 219.00%
0.00%
411.65%
18.28%
DCGN03D FAST H2 Mixing Fan D 26.6 219.00%
0.33% -
411.65%
18.61%
DPBG02A Boric Acid Pump 12.73 213.40%
-0.33%
274.92%
7.81%
A DPBG02B Boric Acid Pump 12.73 213.40%
-0.44%
274.92%
7.70%
B Emergency Fuel DPJE01B 011 Transfer 1.86 230.00%
0.64%
321.51%
10.81%
PumpB DSGN01D FAST Containment 146 230.00%
-0.64%
236.30%
0.25%
Cooler D - Fast
Attachment to ET 19-0020 Page 6 of 9 Control Room SGK04BA NC Compressor B
1 E Equipment SGK05AA NC Compressor A
1 E Equipment SGK05BA NC Compressor B
Brake Horse Power (BHP)
Break Down Torque (BDT)
Full Load Torque (FLT) 3o.n 200.00%
-1.74%
259.99%
6.95%
27.4 200.00%
-1.86%
255.47%
6.29%
27.4 200.00%
-1.70%
255.47%
6.45%
Note*: The actual BHP was used to improve margin.
Therefore, at the current LOVR TS allowable value of 82.SV the Class 1 E motors that are normally running will not stall (Reference 7, Attachment C2), but there is no margin for additional load growth.
- 4.
Loss of Voltage (LOY} Setting In accordance with NEI 15-01 revision 1, Reference 7 evaluated the existing TS SR 3.3.5.3 allowable value for the LOV and non-accident DVR time delay for WCGS Configuration N1, which is a normal (non-accident) operating condition. The DVR Interim Analysis calculation verified that the safety-related motors that are energized for Configuration N 1 will not stall if the safety-related 4.16kV bus voltages decrease to the existing TS SR 3.3.5.3 LOV allowable value.
Reference 7 also verified that the safety-related motors that are energized for Configuration N1 will not trip due to actuation of their overcurrent protective devices if the safety-related 4.16kV bus voltages remain at the existing TS SR 3.3.5.3 LOV allowable value for the entire 130.6 second DVR non-accident time delay when no accident signal is present.
Reference 6, section 4. 7.1.1, evaluated the proposed changes to the LOV and non-accident DVR time delay for WCNOC Configuration L 1, which is an accident condition in which all the safety-related equipment that are required to mitigate the consequences of an accident are energized. This provides margin for long term operation by ensuring that no safety-related motor will stall at the LOV setting or trip due to actuation of its overcurrent protective device during the DVR non-accident time delay.
- 5.
Control Relays, Contactors and Fuses Additionally, the DVR Interim Analysis reviews the performance of control relays and contactors along with its fuses. The review determines that none of the control relays and contactors fail to perform during the postulated DV and time delays of the TS allowable values. Also, all the fuses remain intact during the postulated DV conditions of the analysis.
==
Conclusion:==
Revising the TS SR 3.3.5.3 allowable values, nominal Trip Setpoints, and time delays as proposed in the LA.R for the DVR and loss. of voltage relay (LOVR) will improve the design margins for equipment running voltages and Class 1 E Bus voltages. The proposed LA.R also provides margin for the replacement or refurbishment of Class 1 E equipment in the future to maintain qualified status. These actMtles often result in changing the operating characteristic of the equipment as analyzed; hence, further narrowing the current margin.
Attachment to ET 19-0020 Page 7 of 9 Therefore, revising the TS SR 3.3.5.3 allowable values, nominal Trip Setpoints, and time delays as proposed in the LAR would increase margin to allow for long term operation.
NRC Clarification Request Regarding RAI No. 6 The LAR stated that the evaluations, which were based on NE/ 15-01 methodology, showed that the overcurrent devices met the acceptance criteria (no tripping during starting of a load) except for 20 TOLs [Thennal Overloads].
For these 20 TOLs, an enhanced overcurrent evaluation was perfonned. In response to RAJ No. 6, in its Jetter dated September 10, 2019, it was also stated that ETAP Dynamic Motor Acceleration analysis was perfonned as part of enhanced overcurrent evaluation for 20 TOLs.
During audit of the licensee Calculation XX-E-009-001-CN006 [which included vendor Calculation KCI-XX-E-009, Rev 1, Attachment B4, "Enhanced Evaluation of TOLs at Joss of voltage relay (LOVR) Lower Analytic Umit for Concurrent LOCA and Degraded Voltage Condition"}, the NRG staff finds that enhanced evaluation was perfonned for 30 TOLs instead of 20 TOLs.
Please explain the discrepancy between Calculation XX-E-009-001-CN006 (according to which the enhanced evaluation was perfonned for 30 TOLs) and the LAR (which states that enhanced evaluation was perfonned for 20 TOLs).
WCNOC Supplemental Response The enhanced method was performed on 30 thermal overloads (TOLS), as shown in Attachment C of Reference 6, not on 20 TOLs as indicated in the LAR. This administrative engineering error was carried over from the calculation summary of Reference 6 (page 56 out of 100) to the LAR. Condition Report (CR) 1'37326 has been written to track and correct this error via an administrative calculation change notice (CCN).
NRC Clarification Request Regarding RAJ No. 8 In its response to No. 8, in Jetter dated September 10, 2019, the it was stated that File - K01-058 is attached. However, this file was not included in the RAJ rf}sponse.
Please either provide a copy of the referenced file or revise the RAJ response to delete reference to this file.
WCNOC Revised Response The response provided in Reference 3 has been revised to delete the proprietary response.
The revised response is provided below.
The lowest switchyard voltage as 98% of 345 kV rated voltage is based on NERC Interface Agreement between Westar Energy (transmission system operator entity) and WCNOC. Per NERC Reliability Standard NUC-001-3 and Interface Coordination Agreement (Interface
Attachment to ET 19-0020 Page 8 of 9 Coordination Agreement between Westar Energy and WCNOC), the minimum and maximum switchyard steady state voltages will be maintained ~ 98% and s 104.5% of rated voltage.
WCNOC requires that the switchyard be operated within the established minimum and maximum steady state voltages of :2:: 98% ands 104.5%. This is described in WCGS Updated Safety Analysis Report (USAR), Chapter 8, section 8.2.1.1 Transmission Network.
NRC Clarification Request Regarding RAJ No. 9 In its response to RA/ No. 9, in letter dated September 10, 2019, it was stated, "The methodology to perform the motor stall voltage is detailed on section 4. 7. 1. 5 section B
[Ref: XX-E-009-001-CN006]."
RA/ No. 9 requested a discussion of the methodology to perform the motor stall voltage. The response to the RA/ by letter dated September 10, 2019, included a reference to a section of calculation XX-E-009-001-CN006, but the relevant summary of the calculation section or the discussion of the methodology was not included with the response.
Please provide a brief description of methodology used for calculating motor stall voltages.
WCNOC Supplemental Response To prevent a motor from stalling, the minimum available breakdown torque from the motor must be equal to the required full load torque. However, at rated voltage, the available breakdown torque is greater than the required full load torque. As voltage decreases, the available breakdown torque decreases. Therefore, the minimum allowed motor terminal voltage can be calculated for the torque value where the minimum available breakdown torque from the motor equals the required full load torque for the load.
The equation used to calculate the minimum allowed load voltage is as follows (section 4.7.1.5 section B, Reference 6).
where:
Vmm allowed = Vrateci *..J ((%BDT@Vmm allowed) I (%BDT@Vra1ed))
V m In allowed = the minimum allowed motor terminal voltage V ratoo = the rated voltage for the motor
(
%8DT@Vmm allowed= the minimum required ratio of breakdown torque to full load torque at the minimum allowable voltage for the load
%8DT@Vrated = the available ratio of breakdown torque to full load torque at rated voltage for the motor Reference 5, Appendices 5 and 58, as well as National Electrical Manufacturers Association (NEMA) Standard MG 1, "Motors and Generators," were used as design inputs for the available ratios of breakdown torque to full load torque at rated voltage for the motors.
The required full load torque at rated voltage for the motor was adjusted based on the brake horsepower (BHP) data in Reference 5 that was used to determine the minimum required ratio of breakdown torque to full load torque.
Attachment to ET 19-0020 Page 9 of 9 Torque is proportional to power:
where:
Pmotor = the motor BHP T motor = the motor torque w = the motor speed P motor= T motor
- w The motor stall voltage was compared against the motor terminal voltage calculated in the Electrical Transient and Analysis Program (ETAP) load flow at the analytical limit of the LOVR 3150V to verify that the motor will not stall (Reference 6, Attachment C).
References:
- 1.
WCNOC Letter ET 19-0002, "License Amendment Request to Revise Tecilnical Specification 3.3.5, "Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation,"
March 18, 2019. ADAMS Accession No. ML19086A111.
- 2.
Letter from B. K. Singal, USNRC, to S. L. Smith, WCNOC, "Request for Additional Information Re: Revision to Technical Specification 3.3.5, 'Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation' Wolf Creek Generating Station (EPID No. L-2019-LLA-0062)," August 12, 2019. ADAMS Accession No. ML19224A524.
- 3.
WCNOC Letter ET 19-0019, "Response to Request for Additional Information "Revision to Technical Specification 3.3.5, Loss of Power (LOP) Diesel Generator (DG) Start Instrumentation," September 10, 2019. ADAMS Accession No. ML192600630.
- 4.
Electronic mail from B. K. Singal, USNRC, to N. R. Good, WCNOC, "License Amendment Request to Revise Wolf Creek Generating Station Technical Specification 3.3.5 - Follow-up Discussion to RAI Response (EPID No. L-2019-LLA-0062)," October 7, 2019.
- 5.
Calculation XX-E-006, Revision 8, "AC System Analysis," May 24, 2018.
- 6.
Calculation XX-E-009, Revision 001, Change Notice 006, "System NB, NG, PG Under Voltage/Degraded Voltage,u October 31, 2018.
- 7.
Calculation XX-E-041, Revision 00, "Degraded Voltage Relays Interim Analysis,"
October 21, 2019.