ML042260356
| ML042260356 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 08/06/2004 |
| From: | Korsnick M Constellation Energy Group |
| To: | Clark R Office of Nuclear Reactor Regulation |
| References | |
| Download: ML042260356 (24) | |
Text
Maria Korsnick Vice President 1503 Lake Road Ontario, New York 14519-9364 585.771.3494 585.771.3943 Fax maria.korsnick @ constellation.com Constellation Energy R.E. Ginna Nuclear Power Plant August 6, 2004 Mr. Robert L Clark Office of Nuclear Regulatory Regulation U.S. Nuclear Regulatory Commission Attn:
Document Control Desk Washington, D.C. 20555-0001
Subject:
References:
Response to Information Requested In Phone Conversation on February 23,2004 Pertaining to Control Room Emergency Air Treatment System (CREATS) Diesel Generator Loading and Electric Breaker Analysis R.E. Ginna Nuclear Power Plant Docket No. 50-244
- 1. Letter from Robert C. Mecredy (RG&E) to Robert L. Clark (NRC) dated May 21, 2003, License Amendment Request Regarding Revision of Ginna Technical Specification Sections 1.1, 3.3.6, 3.4.16, 3.6.6, 3.7.9, 5.5.10, 5.5.16, and 5.6.7 Resulting From Modification of the Control Room Emergency Air Treatment System and Change in Dose Calculation Methodology to Alternate Source Term.
- 2. Letter from Robert C. Mecredy (RG&E) to Robert L. Clark (NRC) dated February 16, 2004, Detailed Design Information for Proposed CREATS Modification and Locked Rotor Failed Fuel Estimation.
Dear Mr. Clark:
In a phone conversation with RG&E staff on February 23, 2004, you requested design analysis results pertaining to diesel generator loading and breaker sizing relevant to the CREATS modification, as described in the Overview of Electrical Information contained in Reference 2.
The attachments to this letter contain the requested Information and should be docketed as an addendum to Reference 1. If you have questions regarding the content of this correspondence please contact Mr. Mike Ruby at (585) 771-3572 or Mr. George Wrobel at (585) 771-3535.
Very truly yours, i1Wa4~d, Mary G.
rsnick tob o
STATE OF NEW YORK
- TO WIT:
COUNTY OF WAYNE I, Mary G. Korsnick, being duly swom, state that I am Vice President - R.E. Ginna Nuclear Power Plant, LLC (Ginna LLC), and that I am duly authorized to execute and file this response on behalf of Ginna LLC. To the best of my knowledge and belief, the statements contained in this document are true and correct. To the extent that these statements are not based on my personal knowledge, they are based upon information provided by other Ginna LLC employees and/or consultants. Such information has been reviewed in accordance wi company practice and I believe it to be reliable.
Subscribed and sworn before me, a Notary Publigin and for the State of New York and County of this G
day of Lu
, 2004.
WITNESS my Hand and Notarial Seal:
/
'1
/
Notary Public SHMON L MLER My Commission Expires:
aPk NYok h% 02 1-04 6 nmEffiOW~
Date Attachments:
- 1.
Summary - Impact of CREATS Modification on Diesel Generator Dynamic and Steady State Results
- 2.
Summary - Breaker Sizing Review for New CREATS Loads Cc:
Mr. Robert L. Clark (Mail Stop 0-8-C2)
Project Directorate I Division of Licensing Project Management Office of Nuclear Regulatory Regulation U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Rockville, MD 20852 Regional Administrator, Region 1 U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 U.S. NRC Ginna Senior Resident Inspector
Mr. Peter R. Smith New York State Energy, Research, and Development Authority Corporate Plaza West 286 Washington Avenue Extension Albany, NY 12203-6399 Mr. Paul Eddy NYS Department of Public Service 3 Empire State Plaza, 10th Floor Albany, NY 12223 James M. Petro Jr., Esquire Counsel Constellation Energy 750 East Pratt Street, 5th Floor Baltimore, MD 21202 Daniel F. Stenger Ballard Spahr Andrews & Ingersoll, LLP 601 13th Street, N.W., Suite 1000 South Washington, DC 20005 Summary Impact of CREATS Modification on Diesel Generator Dynamic and Steady State Results
Ginna Station Summary - Impact of CREATS modification on Diesel Generator Summary-Impact of CREATS modification on Diesel Generator Dynamic and Steady State Results This document summarizes the impact of the CREATS modification on both the steady state and dynamic performance of the diesel generators. A simplified single line for the new equipment associated with the CREATS modification is shown below. The single line is for the Train A portion of the modification while a similar arrangement exists for the Train B side.
I 0.48 kIV NCCIC 4o~
i 460 Tr 1-3/C 4/0 04CI3k OA4B kIV Y.
lM4 cob10 ft i 1-3/C I Ca
.)M Vancabi.
so c 1-S3C I CU 0.41kV CUW
.Now MuzCablo ISO ft 1-3/C e 0.41rkW XIN cU Cab1.
60 fly 1-3/C 6 0.48-W_-
7.X MkM L
H=Qf Coolulit 0.49kV 1
Cooling t6 kYl 51anHydcan Zs BP Figure 1 -Simplified Single Line - CREATS modification - Train A July 28, 2004 Page 1 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator Dynamic Analysis The existing dynamic analysis (DA-EE-92-1 11-01 and DA-EE-92-112-01) serves as the basis for both the dynamic computer model and acceptance cntena. The existing models were updated to accommodate the newer version of the ETAP computer program (Version 4.7.6N) as well as the changes associated with the CREATS modification.
During the Injection phase of an accident, a timer will start the new 25 hp fan motor approximately 50 seconds after an Si signal. Both the heater and cooling units are controlled manually and will not be turned on until after the injection phase is complete. The 7.5 kVA transformer shown above is expected to be loaded to about 30% of its capacity (2 kW). The new 25 hp fan has a relatively large inertia constant and takes approximately 7 seconds to start when the actual mechanical load is attached and the voltage at the motor terminals is 80% of 48DV.
The loads required to mitigate and accident are sequenced onto the diesel generator in the event that offsite power is not available. The actual sequence used for the Train B simulation is shown below:
Table I - Train B Simulation time (DOG breaker closes at 3.058 seconds)
Load ETAP Simulation Time (sec)
CSP1B, MCC D, MCCJ, MCCM 3.058 S11B 3.332 SliC 8.990 RHR1B 14.061 SWID 18.21 CF1B 23.300 CFIC 28.360 AFWP1B 34.200 CR FAN (new 25 hp) 43.000 It should be noted that the ETAP simulation time sequence shown in the above table does not use SI actuation as time = 0. With respect to that time reference, the ETAP simulation times are all shifted back by about 7 seconds (i.e. DG breaker would really close at 10 seconds rather than 3 seconds). This time shift does not affect the results.
Regulatory Guide 1.9 specifies that during the sequence process, the minimum frequency should not be less than 0.95 per unit (57 Hz) and should be restored to within 2% of nominal (58.8 Hz) within 60% of each load sequence interval. The minimum voltage should not be less than 0.75 per unit and should be restored to within 10% of nominal within 60% of each load sequence interval. In addition the July 28, 2004 Page 2 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator loss of voltage relays on the safety related buses should not operate (they have a 2.5 second delay and will pickup/dropout at 79.67% of 480v).
The following dynamic simulations were performed and the results of these simulations are shown graphically in Figures 2 through19.
- 1. DGA Field Match
- 2. DGA Accident Conditions (prior to CREATS modification)
- 3. DGA Accident Conditions (after CREATS modification)
- 4. DGB Field Match
- 5. DGB Accident Conditions (prior to CREATS modification)
- 6. DGB Accident Conditions (after CREATS modification)
The DGA Field Match (Figures 2-4) and DGB Field Match (Figures 11-13) were performed in order to demonstrate the adequacy of the mathematical model.
These figures demonstrate a reasonable correlation between actual measured values of frequency, electric power and voltage with the corresponding results out of the ETAP computer program. The field results are shown in red while the simulated results are shown in blue.
The brake horsepower loading on many of the motors is reduced during the field tests because the pumps are generally put in "recirculation" mode and the fans are operating under non-accident condition pressures. This results in the final load on the diesels being about % of what it would be during true accident conditions (Figures 3 and 12). The brake horsepower on these motors is Increased in the ETAP computer model for the accident condition simulations.
Even though the Train A and Train B system are nearly identical, the voltage performance of the two systems is quite different as can be observed by comparing Figures 4 and 13. This difference Is most likely due to variations in the voltage regulator gain and time constant settings. The Train B system has a more Obouncy" voltage profile, which Is not necessarily bad; the Important point Is that while the two systems perform differently they both satisfy the design criteria.
It should be noted that the Train B system is more prone to activating the loss of voltage relay (Figure 19) as compared to the Train A system (Figure 10). The loss of voltage relay is only activated for about 0.5 seconds (Figure 19) and the relay has a 2.5 second delay so an Inadvertent relay operation should not occur.
As expected, the only significant difference in the Obefore CREATS" and "after CREATS dynamic simulations occurs after time = 43 seconds which Is when the new 25 HP fan Is sequenced on. An important observation from the "after CREATS simulations is that the maximum peak transient kW associated with turning on the 25 HP motor Is less than previous peaks experienced earlier in the sequence (Figures 9 and 18). It can also be noted that the frequency variations associated with turning on the 25 HP motor Is significantly less than what was experienced earlier in the sequence (Figures 8 and 17). Both of these July 28, 2004 Page 3 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator observations suggest that turning on the 25 HP motor is not going to force the governor controls to hit new extreme points. Similarly the voltage variations resulting from turning on the 25 HP motor are minor compared to that experienced earlier in the simulation (Figures 10 and 19) suggesting that the voltage regulator and exciter are not going to hit new extreme points. Therefore it is not surprising that the simulations demonstrate a successful acceleration of all of the loads even after the 25 HP CREATS load is added to the sequence.
Figure 8 and Figure 17 demonstrate that the frequency for the Nafter CREATSw case does not get down to 57 Hz and recovers above 58.8 Hz within the prescribed time limit. Figure 10 and Figure 19 demonstrate that the voltage for the Oafter CREATES case does not get down to 75% and recovers above 90%
prior to the prescribed time limit.
The Impact of the CREATS modification on the dynamic performance of the diesel generators can best be described as minimal. No violations of the design criteria are expected as a result of this modification.
Steady State Loading The existing steady state loading analysis (DA-EE-92-098-01 and DA-EE 120-01) serves as the basis for evaluating the impact of the CREATS modification on the diesel generator steady state loading. During the injection phase only the fan and the associated controls will be energized. This adds a total of 21 kW + j 10 kVAR of load. The following table summarizes the before and after loading on Diesel Generator A.
Table 2 Diesel Generator A Steady State Loading - Injection Phase I
Diesel Generator A Steady State Loading - Injection Phase Diesel Rating Diesel Loading CREATS
%kW Status Duration kW kVAR kW kVAR Dut Before 30 Minutes 2300 1462 1982 86.2 974 66.6 Before Two Hours 2250 1462 1982 88.1 974 66.6 Before Continuous 1950 1462 1982 101.6 974 66.6 After 30 Minutes 2300 1462 2003 87.1 984 67.3 After Two Hours 2250 1462 2003 89.0 984 67.3 After Continuous 1950 1462 2003 102.7 984 67.3 The above table indicates that the CREATS modification added about 1% to the loading of the diesel. The 102.7 % kW duty for the continuous duration time period is not a problem because the injection phase lasts less than 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for a worst case loading scenario (large break LOCA) and then the loading on the diesel is reduced (as shown below).
The above calculation does not take any credit for the existing CREATS equipment that will be removed.
July 28, 2004 Page 4 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator The following tabulation reflects the worst case loading on Diesel Generator after the Injection Phase is complete. In this case, the CREATS modification is assumed to add an additional 28 kW of heater load in addition to the previously mentioned 21 kW + J 10 kVAR. All loading values are now well within the rating of the diesel generator.
Table 3 - Diesel Generator A - Steady State Loading _ High Head Recirculation Phase Diesel Generator A Stnadv State Loadinn - Hinh Head RecrIrculatinn Phase Diesel Rating Diesel Loading CREATS
%kW
% VAR Status Duration kW kVAR kW Duty WAR Before 30 Minutes 2300 1462 1664 72.3 786 53.8 Before Two Hours 2250 1462 1664 74.0 786 53.8 Before Continuous 1950 1462 1664 85.3 786 53.8 After 30 Minutes 2300 1462 1713 74.5 796 54.4 After Two Hours 2250 1462 1713 76.1 796 54.4 After Continuous 1950 1462 1713 87.8 796 54.4 The results for the Train B steady state loading is very similar to that described above for the Train A analysis. The corresponding tables for Train B are presented below:
Table 4 - Diesel Generator B - Steady State Loading _ Injection Phase Diesel Generator B Steady State Loading - Injection Phase Diesel Rating l
Diesel Loading CREATS
% kW VAR Status Duration kW kWAR kW Duty kVAR Duty Before 30 Minutes 2300 1462 1962 85.3 960 65.7 Before Two Hours 2250 1462 1962 87.2 960 65.7 Before Continuous 1950 1462 1962 100.6 960 65.7 After 30 Minutes 2300 1462 1983 86.2 970 66.3 After Two Hours 2250 1462 1983 88.1 970 66.3 After Continuous 1950 1462 1983 101.7 970 66.3 Table 5 - Diesel Generator B - Steady State Loading - High Head Recirculation Phase Diesel Generator B Steady State Loading - High Head Recirculation Phase Diesel Rating Diesel Loading l
CREAT E
kW
% kWAR Status Duration kW kWAR kW Duty kVAR Duty Before 30 Minutes 2300 1462 1647 71.6 775 53.0 Before Two Hours 2250 1462 1647 73.2 775 53.0 Before Continuous 1950 1462 1647 84.5 775 53.0 After 30 Minutes 2300 1462 1696 73.7 785 53.7 After Two Hours 2250 1462 1696 75.4 785 53.7 After Continuous 1950 1462 1696 87.0 785 53.7 July 28, 2004 Page 5 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator The impact of the CREATS modification on the steady state loading of the diesel generators can best be described as minimal. No violations of the design criteria are expected as a result of this modification.
July 28, 2004 Page 6 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator DGA Field Match - Using ETAP 4.76N - July 9, 2004 07-09-2004 DGAFieldMat Match 1996 field results DGA96-DSP (4/27197) and DGA96MY-OUT t5/12/97) - Final Field Match RSSP TEST OF DGA 1996 WITH 300 HP SW MOTOR DATE 05-12-1996 TIME 04:13:00.00 Target File Extrema >>>
Max = 63.84 at time =2.93 Min = 0.00 at time =0.02 Freq (Hz)
Max = 62.39 at time =2.66 Min = 57.78 at time =4.11 65.00 60.00 55.00 V
20.00 Time (sec) 40.00 Figure 2 - DGA Frequency Match 07-09-2004 DGAFieldMat Match 1996 field results DGA96.DSP (4/27/97) and DGA96MY.OUT (5/12/97) - Final Field Match RSSP TEST OF DGA 1996 WITH 300 HP SW MOTOR DATE 05-12-1996 TIME 04:13:00.00 Target File Extiema >>>
Max = 1-53 at time =29175 Min = 0.00 at time =0.98 Elec (MW)
Max = 1.56 at time =29.61 Min = -0.02 at time =2.92 2.00 1.00 0.00 0.00 20.00 Time Isec 40.D.00 Figure 3 - DGA MW Match COcr July 28, 2004 Page 7 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator Figure 4 - DGA Voltage Match
( 0?
July 28, 2004 Page8 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator DGA - Accident Conditions (Prior to CREATS) 07-09-2004 DGAAccdnt Accident Simulation - Injection phase Fieq (Hz)
Max - c:
65.00 -- -
'.65 at time =2.64 Min - 57.26 at time =4.09 20.00 Time (sec]
40.0 60.00 55.fl0- I 0.00
.00 Figure 5 - DGA Frequency Plot - Prior to CREATS 07-09-2004 DGA Accdnt Accident Simulation - Injection phase Elec (MW)
Max -2.23 at time =33.11 Min -
0.00 at time =2.20 2.00--
0.0--i
-4
---
0.00 20.00 Tie(tec) 40.00 Figure 6 - DGA MWe Plot - Prior to CREATS (final output E 2.0 MW + 0.89 MVVAR)
July 28, 2004 July 28, 2004 Page 9 of 18 R v s o Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator 07-09-2004 DGA Accdnt Accident Simulation - Injection phase Volts tMag Max -
123158 at time -2.34 Min - 81.75 at time -3.69 125.00 100900
~:-
75.00 1
i 0.00 20.00 Time (sac) 40.00 Figure 7 - DGA Bus 14 Voltage - Prior to CREATS (% of 480)
July 28, 2004 Page 10 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator DGA - Accident Conditions (After CREATS Addition -
Start 25 HP Fan at Time = 50 Seconds after Si = 43 sec in simulation) 07-1 2-2004 DGAAccdnt Accident Simulation - Injection phase. MCCN and CR Fan 25hp turned on at 50 sec after Si (sim time -
Freq (Hzi 65.00 Max-I
-it 60.00 62.58 al time -2.64 Min -
57 31 at time *4 05
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I 30.00 Time [secl 60 00 55.00 0.00 Figure 8 - DGA Frequency After CREATS July 28, 2004 Page 11 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator 07-12-2004 DGAAccdnt Accident Simulation - Injection phase. MCCN and CR Fan 25hp turned on at 50 sec after Si (sim time =
Elec (MW)
Max = 2-28 at time =33.11 Min = 0.01 at time =2.20 2.00 1.00 0.00 0.00 30.00 Time (sec) 60.00 Figure 9 - DGA MWe After CREATS 07-12-2004 DGAAccdnt Accident Simulation - Injection phase. MCCN and CR Fan 25hp turned on at 50 sec after Si (sim time =
Volts ZMag Max = 123.59 at time =2.34 Min = 81.44 at time =3.69 125.00 100.00 75.00 0.00 30.00 Time (sec) 60.00 Figure 10 - DGA Bus 14 Voltage - After CREATS (% 480) o 3 July 28, 2004 Page 12 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator DGB Field Match - Using ETAP 4.76N - July 11, 2004 07-11-2004 dgb_fldmat Match 1996 field results DGb96 DSP - Final Field Match rssp test of dgb 1996 with new sw DATE 05-12-96 TIME 07:00 Target File Extrema >>>
Max = 62.35 at time =2.71 Freq (Hz)
Max = 62.47 at time =2.86 Min = 0.00 at time =0.02 Min = 58.52 at time =4-03 65.00 60 00 55.00 20.00 Time (sec) 40.00 Figure 11 - DGB Frequency Match 07-11-2004 dgbfIldmat Match 1996 field results DGb96.DSP - Final Field Match rSSp test of dgb 1996 with new sw DATE 05-12-96 TIME 07:00 Target File Extrema >>>
Max = 1.53 at time =30.90 Elec (MW)
Max = 1.50 at time =30.76 Min = 0.00 at time =0.71 Min = 01 at time =3.04 2.00 1.00 0.00 20.00 Time (seci 40.00 0.00 Figure 12 - DGB MW Match Coay Revision 0 July 28, 2004 Page 13 of 18
Ginna Station Summary - Impact of CREATS modification on Diesel Generator Figure 13 - DGB Voltage Match C0-5 July 28, 2004 Page 14 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator DGB - Accident Conditions (Prior to CREATS) 07-12-2004 dgb__accdnt dgb-accident conditions - prior to MCCN being added Freq (HzJ Max -
62.64 at time -i 65.00 60.00 2 84 Min -
58.25 at time -3 89 r
F F
F
'V' 55.00 0.00 I
+
Time (secJ 40.00 20.00 Figure 14 - DGB Frequency Plot - Prior to CREATS 07-12-2004 dgbLaccdnt dgb-accident conditions - plior to MCCN being added Elec IM
-i 1.00. A 0.00 _}
o.
WIW Max -2.30 at time -35.14 Min -
0.00 at time -2.40
- ~~--- -- -- -A---------:
-t-
- -I -
- -+- --
00o 20.00 Time (sec) 40,1.00 Figure 15 - DGB MWe Plot - Prior to CREATS (final output = 2.02MW + J 0.92 MVAR)
July 28, 2004 Page 15 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator 07-1 2-2004 dgbaccdnt dgb-accident conditions - priot to MCCN being added Volts ZMag Max = 12419 at time =2.54 Min = 76.33 at time =3.43 125.00 100.00 75.00 0.00 20.00 Time (seci 40.00 Figure 16 - DGB Bus 16 Voltage - Prior to CREATS (% of 480) - Line - Loss of Voltage relay 2.5 sec delay CO&
July 28, 2004 Page 16 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator DGB-Accident Conditions (After CREATS - Start 25hp Fan at Time = 50 sec After Si = 43 seconds in simulation) 07-12-2004 DgbjAcc.P dgb-accident conditions - Start CR fan at MCCP at time = 50 seconds from Si signal (43 seconds in si Fseq iHz)
Max - 62.58 at time =2.82 Min -
58.31 at time -3.85 65.00 60.00 55.00 h---------------------
0.00 30.00 Tine (eec) 60.00 Figure 17 - DGB Frequency After CREATS July 28, 2004 Page 17 of 18 Revision 0
Ginna Station Summary - Impact of CREATS modification on Diesel Generator 07-12-2004 DgbAccP dgb-accident conditions - Start CR fan at MCCP at time = 50 seconds from Si signal (43 seconds in sii Elec (MW)
Max = 2.31 at time =35.14 Min = 0.01 at time =2.40 2.00 1.00 0.00 0.00 30.00 Time [sec]
60.00 Figure 18 - DGB MWe Plot After CREATS 07-12-2004 Dgb,_AccP dgb-accident conditions - Start CR fan at MCCP at time = 50 seconds from Si signal (43 seconds in sir Volts ZMag Max = 124.20 at time =2.54 Min = 76.33 at time =3.43 125.00 100.00 75.00 0.00 30.00 Time (sec) 60.00 Figure 19 - DGB Bus 16 Voltage - After CREATS (% 480)
July 28, 2004 Page 18 of 18 Revision 0 Summary Breaker Sizing Review for New CREATS Loads
Summary - Breaker Sizing Review for new CREATS Loads This document provides a summary of the sections of design analysis DA-EE-2003-062 performed to determine the appropriate sizing of breakers feeding the new motor control centers (MCCs) and electrical loads being added to supply CREATS equipment. The simplified single line drawing in the Diesel Generator Loading Summary (Attachment 1, page 1) illustrates the arrangement of Train A (MCC N). The identical Train B (MCC P) is not shown.
Loading of each MCC consists of a 25 HP CREATS Fan (measured FLA = 20 amps),
27.8 kw of Heaters, HVAC Unit rated 26 FLA, and a 7.5 kva 480/120 vac transformer supplying 120 vac loads. Overall MCC loading was calculated with the assumption that both heating and cooling would not run coincident. Breaker sizing was then selected to provide adequate capacity to supply each load while protecting downstream cables.
Coordination was maintained between the in line breakers.
The feeder breakers to MCC N (P) from existing 480 volt MCC C (D) are 100 amp thermal magnetic breakers, sized to provide over 125% of expected capacity. The breakers were also reviewed to ensure cable protection to the 4/0 feeder cable, including all cable deratings. Coordination curves were created versus upstream MCC and bus breakers to ensure adequate coordination.
All breakers are rated for 65 KAIC interrupt rating, which was reviewed against Ginna short circuit analysis and shown to be rated adequately.
Each load breaker in the new MCCs N & P are sized to carry a minimum of 125% of expected load and have an instantaneous setting of 173% of the motor's locked rotor current, while providing adequate cable protection. The three breakers supplying the Fan, Cooler, and Heater are each fed through a 50 amp magnetic-only breaker via a contactor with a built in thermal overload device appropriately sized for the load. The transformer is fed by a 20 amp thermal magnetic breaker sized for full transformer rating.
In conclusion, the analysis indicates that the electrical equipment selected to provide power to the new CREATS system and associated components is properly sized for the application.