ML17340A512

Forwards Addl Info Re Distribution Sys Voltages,In Response to NRC 800819 Ltr.Since Safety Injection Signal Initiates Automatic Fast Transfer from Auxiliary Transformer to Startup Transformer,Only Connection Via Startup Analyzed

ML17340A512
Person / Time
Site:	Turkey Point
Issue date:	12/18/1980
From:	Robert E. Uhrig FLORIDA POWER & LIGHT CO.
To:	Varga S Office of Nuclear Reactor Regulation
References
L-80-411, NUDOCS 8012240430
Download: ML17340A512 (28)

Text

REGULA 'RY INFORMATION'DISTRIBUTI SYSTEM (RIDSi ACC) SS ION NBR".80 1'2240430 DOC ~ DATE: 80/12/18 NOTARIZED; NO DOCKET FA$ 'fL:50-250 Turkey Point Pl anti Uni t 3R Fl or ida Power and Light C S0-2S1 BYNAME Turkey Point Planti Unit 4E Florida Power and Light 'C AUTH AUTHOR AFFILIATION UHRIGER.E. Florida Power 8 Light Co.

RECI'P ~ NAME RECIPIENT AFFILIATION VARGApS,A,~ . Operating Reactors Branch 1

SUBJECT:

Forwards addi info re distribution sys vol tagesiin response to NRC 800819 tr.Since safety injection signal initiates 1

automatic fast transfer from auxiliary transformer to startup transformer<only connection via startup anal.yzed, DISTRIBUTION CODE: AO IBS COPIES:RECEIVED:LTR TITLE: Onsite Emergency Power Systems ENCL ~

~

SIZE:~ 'P NOTES:

RECIPIENT COPIES RECIPIENT COPIES Io CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENC'L ACTION: VARGA:E S ~ 04 7 7 INTERNAL: AEOD 1 GEN ISSUES BR13 1 1 I8,C SYS BR 09 1 1 I 8'E 06 2 2 MPA 18 1 1 NRC PDR 02 1 1 OELD 17 1 1 OP EX EVAL BRil 1 1 OR A SS BR 12 1 1 POlt(ER SYS BR 14 1 1 tR F ILt 01 1 1 EXTERNAL: ACRS 16 ib 16 LPDR 03 NSIC 05 1 1

'0 80 logy TOTAL NUMBER OF COPIES REQUIRED: LTTR 37 ENCL 37

FLORIDA POWER da LIGHT COMPANY December 18, 1980 L-80-411 Office of Nuclear Reactor Regulation Attention:. .Mr S. A. Varga, Chief Operating Reactors Branch IIIl Division of Operating Reactors U. S. Nuclear Regulatory Commission

.Washington, D. C. 20555

Dear Mr- Varga:

Re:. Turkey Points 'Units 3 8 4 Docket Nos. 50-250 .8 50-251 Adequacy of Station, Distribution S stem Volta es Florida 'Power 8 Light Company's response to a NRC letter dated August 19, 1980, requesting additional information on the above subject is attached.

Very truly yours, Robert E. Uhrig Vice President Advanced Systems 8 Technology REU/PLP/ras Attachment cc: J. P. O'Reilly, Region II Harold F. Reis, Esquire ll3i<'e'8'I 833lh83SHOll.":

38N SA

"'J Lf%5 53";fh%:.

tsol~ASi BESlQ G3AY~333 PEOPLE... SERVING PEOPLE

I'n response to NRC letter to FPL dated August 19, 1980 Y], e: Request for Additional Information, Tux'key Point Units 3 & 4 Adequacy of Station Electric Distribution System (dated July 1, 1980)

Reference:

1) NRC letter to FPL dated August 8, 1979

2) FPL letter to NRC dated November 9, 1979 This response addresses the NRC's request for Additional Information enclosed in the NRC letter to FPL dated August 9, 1980. Clarification of. assumptions and specific voltage analysis results are provided herein. Also provided is information requested concerning loading configurations that require greater than the minimum expected steady-state grid voltage in order to start all safety loads simultaneously.

Guideline 1 (Reference 1) requires that separate voltage analyses be performed, for each connection to offsite power" ...assuming the need for electric power is initiated by (1) an anticipated transient (e.g. unit trip) or (2) an accident, whichever presents the largest load demand situation." At Turkey Point, the largest load demand situation occurs under an accident condition wherein a safety injection signal starts all safety loads simultaneously. In accordance with Guidelines 3 and 5, all automatic actions by the electrical system are assumed to occur as designed. Therefore, since a safety injection signal initiates an automatic fast transfer 'from the auxiliary transformer to the start-up transformer, only the connection to offsite power via the start-up transformer was analyzed.

In order to obviate the need to repeatedly calculate the voltage at the terminals of each safety load for each case analyzed, as implied by Guidelines 6 and 7 (Reference 1), FPL chose to calculate the minimum voltage at each bus required to start each safety load. The highest minimum required voltages calculated for each bus are listed in Attachment A. If the voltage analysis results (above) are higher than those minimum values, then sufficient voltage would exist at the terminals of all safety loads to assure their successful start.

The requirements of Guideline 6 (Reference 1) were addressed in the second and third paragraph of page 2 of our November 9, 1979 response (Reference 2). As stated therein, the minimum expected steady-state grid voltage at Turkey Point is 235 KV and the maximum is 244 KV.

All low vol'tage AC (less than 480V) Class IE busses supplying power to vital instrument or control circuits at Turkey Point are powered by inverters supplied from the 125 VDC batteries. Being independent of offsite power, these busses are not included in the voltage analyses. The heat tracing system is the only safety related equipment powered from busses less than 480V. Since the heat tracing is a purely resistive load, voltage variations vill affect the heat output of the system. llowever, the voltages calculated in the analyses provided herein will have little or no effect on the performance of the heat tracing system because the voltages resulting from these. analyses are the worst momentary voltages that could occur upon start of all safety loads simultaneously. As the starting motors accelerate, the voltages would increase. On this basis, voltage variations due to motors starting is not considered to have any adverse impact on Class IE equipment powered from busses less than 480V.

though Turkey Point is a multi-unit station, the voltages analysis suggested by Guideline 2 (Reference 1) was not performed since the connections to offsite power for Units 3 and 4 are independent of each other and would, therefore, not be different from those provided herein.

In addition to the assumptions contained in the above discussion, the five assumptions listed in our November 9, 1979 response (Reference 2) apply to all cases analyzed. Also, in all cases, no manual load shedding was assumed.

In accordance with Guidelines 3 and 5, tripping of the Steam Generator Feedwater Pumps was assumed since this occurs automatically on a Safety Injection Signal. Unique assumptions for each case analyzed involve which Condensate Pumps, Component Cooling Water Pumps, and Intake Cooling Water Pumps are assumed running at the time of the accidents Two out of three of each of these pumps are normally running, but only the A and B pumps receive a start signal on safety injection actuation. This results in various combinations of starting and running loads as reflected in Attachment B. Attachment C provides the results of the voltage analyses for each case on each unit.

In order to provide assurance that no safety loads could experience excessive voltage (Guideline ll, Reference 1) calculations were performed assuming one-half normal load on the 480V busses, minimum pumps running on the 4KV busses, and maximum voltage (244KV) on the grid. The results are presented in Attachment D.

Since no calculated voltage is in excesses of 10% of the equipment nameplate (460V or 4000V), the results are considered satisfactory.

In accordance with the subject NRC Request, additional voltage analyses were performed assuming all safety loads have started and are running, and the largest non-Class IE motor is started. (Motor operated valves are assumed to have completed their action} Because the 7000 HP Steam Generator Feedwater Pumps it

~

are tripped off on a Safety Injection Signal, is possible that an operator could re-start a pump after the safety loads are running (although such action in not per procedure) and is not required for safe shutdown). Only two cases for each unit were analyzed:

Case 2 (Attachment B), which results in the highest load on the "A" train, was assumed when starting the "A" Steam Generator Feed-water Pump.

Case 13 (Attachment B) which results in the highest load on the "B" train, was assumed when starting the "B" Steam Generator Feedwater Pump.

The results of these analyses are tabulated in Attachment E. Also tabulated are the bus voltages required to maintain minimum guaranteed starting voltages at the running safety equipment terminals. (These voltages are based on voltage drops due to full load current. Attachment A voltages are based on voltage drops due to starting currents). Only in the case where the 38 Steam Generator Feedwater Pump is started does an analyzed voltage fall below the required voltage. In this case, HCCD is less than 1.8. volts low. Since the equipment is capable of starting and running at the required voltage, it is reasonable to assume that running equipment will continue to run at the analyzed voltage during the starting of the Steam Generator Feedwater Pump.

In any event, the voltages do not decrease sufficiently to cause starters or contactors to drop out. On this basis, the results of these analyses are considered satisfactory.

1;) order to verify the accuracy of the voltage analyses, voltage and current measurements were made at all Class IE busses. A voltage analyses was then performed using the measured loads and'he resulting voltages compared with the measured voltages. The close correlation between the measured and calculated values (less than 3% difference) provides assurance that the mathematical model used in the voltage analyses is accurate.

In response to Items 5 and 6 of the subject NRC request for Additional Information, the loading configurations that require greater than the cases 13 and 14 in and result in the calculated'us voltages provided for those cases in Attachment C for Unit 3 only. The operators at Turkey Point have been instructed to avoid operation under these loading configurations. If, due to equipment malfunction, the plant is required to be operated in one of these configurations, the operators have been instructed to ensure that the switch-yard voltage remains above that .which analyses indicate is sufficient to safely start all safety equipment. If, while operating in one of these loading configurations, the switchyard voltage decreases below the analyzed safe voltage for, that configuration, the operators are instructed to,decrease the unit's output and thus lower the demand on the electrical system. Such "reduction of loading" as quoted in Item 6 of the subject:NRC request does not imply manual load shedding in that no motor or, equipment is shutdown,.

The reduction of load on the electrical auxiliary system is due to lower power required by the various process pumps in the plant. However, as stated in our letter of November 9, 1980, a design modification is in progress,to add undervoltage relay protection to the 4160V and 480V load center. This modification, will eliminate the need for administrative restrictions on operation of the plant.

In response to Item 4 of the subject NRC request, please refer to our response to NRC letter to FPL dated July 26, 1979 attached to FPL letter to NRC dated November 9, 1979 (Reference 2).

The review requested by Item 2 of the subject NRC request is contained in Chapter 8 of the Turkey Point FSAR.

A tachment A Page 1 of 1 HIGHEST iilININUllVOLTAGES RE UIRED TO START SAFETY LOADS Unit 3 4KV Bus 3A 3214.4V 4KV Bus 3B 3213.5V 480V Load Center 3A None starting 480V Load Center 3B None starting 480V Load Center 3C None starting 480V Load Center 3D None starting 480V HCC 3A 381.4V 480V iICC 3B 392.2V 480V i~lCC 3C 399.9V 480V >jcc 3D . 398.3v Unit 4 4KV Bus 4A '215.8V 4KV Bus 4B 3213.4V 480V Load Center 4A None starting 480V Load Center 4B None starting 480V Load Center 4C. None starting 480V. Load Center 4D None starting 480V >1CC 4A 402.9V 480V i~lCC'4B 396.7V 480V;lCC 4C 393.1V

Attachment B Page 1 of 1 L ADING CONFIGURATIOiVS In all loading configuration cases listed below, the Safety Injection Pumps and RHR Pumps (1 each per 4KV bus) are assumed to start and the Heater Drain Pumps (1 per bus), Turbine Plant Cooling Mater Pumps (1 per bus), circulating Mater Pumps (2 per bus), and the Reactor Coolant Pumps (1 on A bus, 2 on B bus) are assumed to be running. The Steam Generator Feedwaeer Pumps are tripped off upon Safeey Injection Signal. The running and starting loads on the 480V load centers and motor conerol centers do not vary between, cases analyzed. The cases listed below apply equally to Unit 3 and Unit 4.

Case Condensate A B Pumps C

+ Comp. Cooling Water Pumps +

B~: C Ai'i'c Intake Cooling Water Pumps +

OFF RUN RUN START RUN RUN START',., .:,.RUN,!;,RUN, ;,

RUiV OFF RUN START RUN RUN START RUN RUN OFF RUiN RUN RUN START RUVi START RUN RUN RUN OFF RUN RUVi START RUN START RUN RUN OFF RUN RUN RUN RUN OFF START RUN RUN RUN OFF RUiN RUN RUN OFF START RUN RUiV OFF RUN RUN START RUiN RUiV RUN START RUN RUN OFF RUiV START RUN RUN RUN START RUiV OFF RUiV RUiV RUN START RUN RUN START RUN 10 RUN OFF RUN RUiV START RUN RUN START RUN OFF RUiN RUN RUN OFF RUN START RUN 12 RUN OFF RUiV RUN RUiV OFF RUiV START RUiV OFF RUN RUiV 'TART RUN RUN RUN RUN OFF 14 RUN OFF RUN START RUN RUN RUN RUiV OFF OFF RUiV RUN 'UN START RUN RUN RUN OFF 16 RUVi OFF RUN RUiV START RUN RUN RUN OFF OFF RUN RUiV RUN RUiV OFF RUN RUiV OFF 18 RUN OFF RUiV RUN RUiN OFF RUN RUiV OFF

+ Two out of three normally running Pumps start automatically on S.I.S. if not already running.

Attachment C Page 1 of 18 VOLTAGE ANALYSIS RESULTS CASE 1 UNIT 3 UNIT 4 BUS VOLTAGES (Grid at 235'V) 4KV Bus A* 01 4KV Bus A** q q. s8tq 4KV Bus B'+

4KV Bus B:"~ 3851 3861 480V LC A 432 417 480V LC B 422 423

'80V LC C 419 432 480V LC D 430 428 480V NCC A 430 480V /ICC 403 407 430 B'80V NCC C 480V NCC D 405

~High - side of current limiting reactor

• • Low-side, of current limiting reactor

+Not on Unit 4

Attachment C Page 2 of 18 VOLTAGE ANALYSIS RESULTS CASE 2

'k UNIT 3 UNIT 4 BUS VOLTAGES (Grid at 235 KV) 4KV Bus A* 3 03 38 8 4KV Bus A** . 3786 3781 F,

i 4KV Bus B* 3944 3953 4KV Bus B** 3876 3888 480V LC A 429 415 480V LC B 425 426 480V LC C 416 480V LC D 433 432 480V HCC A 427 408 480V HCC B 406 418 480V'CC C 404 427 480V'?ICC D 409

<<High side of current limiting reactor

• • Low-side. of current limiting reactor

+Not on Unit 4

Attachment C Page 3 of 18 VOLTAGE ANALYSIS RESULTS CASE 3 UNIT 3 UNIT 4 BUS VOLTAGES (Grid at 235 KV) 4KV Bus A* 3953 3951 4'us A** 3864 3862 4KV Bus B* 3894 3901 4KV Bus B** 3797 3807 480V LC A 438 480V LC B 480V LC C 42 4 480V LC D 423 422 480V Mcc A 436 480V MCC B 397 409 480V >>CC C 413 436 480V MCC D 399

• High side of current limiting reactor

• • Zaw-side of current limiting reactor

~ +Not on Unit 4

Attachment C Page 4 of 18 VOLTAGE ANALYSIS RESULTS cAsE 4 UNIT 3 UNIT 4 BUS VOLTAGES (Grid at,235 KV) 4KV, Bus A* 3 36 4KV Bus A** 3839 3837 4KV Bus B* 3913 3919 4KV Bus B** 3823 3833 480V L 'A 435 421 480V LC B 419 420 480V LC C 422 436 480V LC D 4 480V'CC A 433 480V HCC B 400 412 480V HCC C 410 433 480V HCC D 402

• High side of current limiting reactor

• • Low-side. of current limiting reactor

+Not on Unit 4

Attachment C Page 5 of 18 VOLTAGE ANALYSIS RESULTS cASE 5 UNZT 3 UNIT 4 BUS VOLTSXKS (Grid at 235 KV) 4KV Bus A*

4'us A** 3872 387o q+ ~ jul gu ee'~ )

~ P p I 4KV Bus B* 3931 3939 4KV Bus B** 3855 3865 480V LC A 439 425 480V LC B 423 423 480V LC C 426 44o 480V LC D 43o 428 48OV IICC A 437 418 480V NCC B 4o4 480V HCC C 414 480V i~ICC D 4o6

• High side of current limiting reactor

• • low-side, of current limiting reactor

+Not on Unit 4

Attachment C Page 6 of 18 VOLTAGE ANALYSIS RESULTS CASE 6 UNIT 3 UNIT 4 BUS VOLTAGES (Grid at 235 KV) 4KV Bus A* 3 43 3 40 4KV Bus A** 3847 3844

}

%>> k )<}r 4/>>} ~}'}

~

~ >> -(>>

4KV Bus 3948 '957 B*'KV Bus B~* 3880 3892

.480V LC A 436 422 480V LC B 426 426 480V LC C 423 480V LC D 4S2 480V MCC A 434 415 480V MCC B 406 418 480V MCC C 480V MCC D 409

• Efigh side of current limiting reactor

• • Low-side. of current limiting reactor

+Not on Unit 4

Attachment C VOLTAGE ANALYSIS RESULTS CASE 7 UNIT 3 UNIT 4 BUS VOLTAGES (Grid at 235 KV) 4KV Bus A*

4KV Bus A** 3853 38 o 4KV Bus B* 3901 4KV Bus B** 3809 3818 480V LC A 437 422

'18 480V LC B 418 480V LC C 480V LC D 425 423 480V HCC A 435 416 398 41o 480V HCC B 411 435 480V HCC C 480V HCC D 4oo

~High side of current limiting reactor

'**Low-side, of current limiting reactor

+Not on Unit 4

Attachment C Page 8 of 18 VOLTAGE ANALYSIS RESULTS CASE 8 UNIT 3 UNIT 4 BUS VOLTAGES (Grid at 235 ZV) 4KV Bus A*

4KV Bus A** 3827 824

~

(Vv' 1 ~ V p,? r p q' 4KV Bus B* 3918 3 26 4KV Bus B*~ 3834 384'2o 480V LC A 480V LC B 42o 421 480V LC C 421 43C?

480V LC D 428 427 480V MCC A 432 413 480V MCC B 4ol 413 480V 409 432 MCC C 480V MCC D 4o4

• High - side of current limiting reactor

"*Low-side. of current limiting reactor

+Not on Unit 4

Attachment C Page 9 of 18 VOLTAGE ANALYSIS RESULTS CASE UNIT 3 UNIT 4 BUS VOLTAGES (Grid at 235'V) 4KV Bus A* 78 4KV Bus A** 3 o6 3905

/'ll %

(gA;~ 1A' .;F 0 f) Cwf ~ ~ $ 4g') h )+pl)l",(i i ~ II 4KV Bus B* 3867- '3874 4KV Bus B~* 3755 3764 480V LC A 429 480V LC B 411 480V LC C 4 480V LC D 41 4a 480V NCC A 441 422 480V HCC B 3 2 4o4 480V NCC C 441 480V lICC D 394

• High - side of current limiting reactor

• • Low-side, of current limiting .reactor

+Not on Unit 4

Attachment C P~e 10 of 18 VOLTAGE AHALYSIS RESULTS CASE 10 UNIT 3 U!NIT 4 BUS VOLTAGES (Grid at 235'V) 4KV Bus A*

4KV Bus A** 3881 3880 I

@i yW t W'V ~ <<g r>f~ )'W le~q a ~

4 4KV Bus B* 3884 3892 4KV Bus B."" 3780 3790 480V LC A 440 426 480V LC B 415 480V LC C 427 480V LC D 422 420 480V HCC A 438 480V NCC B 395 407 480V HCC C 438 480V IICC D 397

• High - side of current limiting reactor

<*Zow-side of current limiting reactor

+Not on Unit 4

'E Attachment C Page 11 of 18 VOLTAGE ANALYSIS RESULTS CASE ll UNIT 3 UNIT 4 BUS VOLTAGES (Grid at 235 Ã1) 4KV Bus A* o 4 4'us A**

/i~ p~

'I

~ '4 i~ i ~ 'li ~ 1 1

~ ~ Q s g', p P log% I 4KV Bus '3* Ro12" 4471 Bus B*" 3812 3822 480V LC A 429 480V LC B 418 419 480V LC C 431 480V LC D 425 423 480V 'HCC A 442 423 480V HCC B 399 411 418 442 480V HCC C 401 480V HCC D

\

~Eiigh side of current limiting reactor

• • Low-side. of current limiting eactor

+Not on Unit 4

Attachment C Page 12 of 18 VOLTAGE ANALYSIS RESULTS CASE 12 UNIT 3 UNIT 4 BUS VOLTAGES (Grid't 235 KV) 4KV Bus A*

4KV Bus A**

4)1)1(4$ ~ Alp ~

~ F J)&tggl

'J'

~ gf' kJ 4KV Bus B* 3922 4KV Bus B** 3838 q84 480V LC A 441 427 480V LC B 421 421 480V LC C 428 442 480V LC D 429 427 480V MCC A 439 42o 480V MCC B 4ol 413 480V MCC C 416 43'80V MCC D 404

• High - side of current limiting reactor

~*Low-side of current limiting reactor

+Not on Unit 4

Attachment C Page 13 of 18 VOLTAGE ANALYSIS RESULTS CASE 13 UNIT 3 UNIT 4 BUS VOLTAGES (Gria at 235 KV) 4KV Bus A* 3949 3945 4KV Bus A** .3856 3852 4KV Bus B* 3933 3941 4KV Bus B** 3857 3868 480V LC A 423 480V LC B 423 480V LC C 438 480V LC D 431. 429 435 416 480V 11CC A 480V ailCC B 404 416 480V NCC C 412 480V NCC D 406

• High side of current limiting reactor

• • Low-side of current lim'ting reactor

+Not on Unit 4

0 Attachment C Page 14 of 18 VOLTAGE ANALYSIS RESULTS CASE 14 UNIT 3 UNIT 4 BUS VOLTAGES (Grid at 235 KV) 4KV Bus A*

4KV Bus A** 383o 3827 1 I

~ w il g y g~

4KV Bus B* . 3950 - '3959 4KV Bus B** 3883 3895 480V LC A 434 42o 480V LC B 426 427 480V LC C 421 435 4SOV LC D 434'32 '432'13 480V lICC A 4oY 419 480V HCC B 409 432 480V lICC C 480V lICC D 41o

'I

• High side of current limiting reactor

• • low-side. of current limiting reactor'Not on Unit 4

Attachment C Page 15 of 18 VOLTAGE ANALYSIS RESULTS CASE 15 UNIT 3 UNIT 4 BUS VOLT&DES (Grid at 235'V) 4KV Bus A* 3982 3 81 4KV Bus A** 3909 3908 i lw <<<

4'us il < i< P << '< P < t ~ ~ ~ < ~,

P

< ? I~ '

B* 3899 3906 4):V Bus B."* 3803 3813 480V LC A 443 429 480V LC B 417 480V LC C 43P

'424 423 480V LC D 422 480V NCC A 398 41P 480V HCC B 418 480V i~ICC C 400 480V HCC D

• High side of current limiting reactor

• • m~ N-side. of current limiting reactor

+Not on Unit 4

Attachment C Page 16 of 18 VOLTAGE ANALYSIS RESULTS.

CASE 16 UNIT 3 UNIT 4 BUS VOLTE~ (Grid at 235 KV) 4KV Bus A*

4KV Bus A** 3883 3882

)f ~

I ~

~,"r ' ~ l&l Vigol (1'4(i t

~ ~ (% ~ I 4KV Bus B* " 3916- 3924 4KV Bus B~* 3828 384o 480V LC A 440 426 480V LC B 42o 42o 480V LC C 428 . 441

" 428

426 480V LC D 480V MCC A 438 42o 4oo 412 480V NCC B 415 439 480V NCC C 480V HCC D 4o3

• High side of current limiting reactor

• • Low-side. of current limiting. reactor

+Not on Unit 4

Attachment C Page 17 of 18 VOLTAGE ANALYSIS RESULTS CASE 17 UNIT 3 'UNIT 4 BUS VOLTAGES (Grid at 235 KV) 4KV Bus A*

4KV Bus A** 3 1 16 4KV Bus B'>> 3936 3 44 4KV Bus B** 3861 . 3871 480V LC A 430 480V LC B 480V LC C 431 '445 480V LC D 431 4z9 480V NCC A 423, 404 480V HCC B 419 442 480V iXCC C 480V NCC D 407

• High side of current limiting reactor

• • Le~-side, of current limiting reactor

+Not on Unit 4

Attachment C Page 18 of 18 VOLTAGE ANALYSIS RESULTS CASE 18 UNIT 3 lJNIT 4 BUS VOLTAGES (Grid at 235'V) 4KV Bus A* 3 2 s 6 4KV Bus A** 3891 3890 4KV Bus B* 3953 3962 4KV Bus B"* 3887 3898 480V LC A 441 427 480V LC B 426 427 480V LC C 428 442 480V LC D 435 433 480V hlcc A 439 42o 4o7 419 480V -hlCC B 416 439 48OV hlCC C 41o 480V hlcc D

• High - side of current limiting reactor

• • Low-side. of current limiting reactor

+Not on Unit 4

Attachment D Page 1 of 1 VOLTAGE ANALYSIS RESULTS ASSPiflifG lfINIBIUi~f LOAD & MXI!'fUi~f SWITCHYARD VOLTAGE UNIT 3 UNIT 4 BUS VOLTAGES (Grid at 244 KV) 4KV Bus A* 4326 4326 4KV Bus A** 4312 4312 4KV Bus B* 4325 4328 4KV Bus B** 4311 480V LC A 494 494 480V LC B 494 494 480V LC C 494 480V LC D F06 498 480V HCC A 493 493 480V HCC B 491 493 480V HCC C 493 493 480V l1CC D 500

• ffigh side of current limiting reactor

• • Low-side of current limiting reactor

+Not on Unit 4

Page 1 of 2

~'OL~AG- hN" L~STS B" SUL' Uil"" 3 ASSU?~iING SAFE'Y LOAD HUlli?ZNG AllD STAR ZNG OF LARGEST llOH-CLASS lE LOAD BUS VOL~KG=S (Gr'd at 235 KV)

BUS REQUIRED CASE 2 CASE 13

~ 5 A IW NONE 3537 4OO8 32O4 34 2 3 70 4-'qt NONE 3 82 35O4

" 'Vi Bus 32O4 3 3 346 3'0; 38O l:80V ' 448 ~33

)~ 8Pq ~ rs C NONE 3 6 48 "V ..C D 4 6 480V:!".C NONE 44o 48OV:'CC 442 48Or i:.CC C 86 48O'! iiCC D 442

• bligh side of current limiting reactor

• *.-'Low-side of current limiting reactor

Att"chment E Page 2 of 2 VOLTAGE ANALYSiS B" SULTS - UIIIT -",

ASSUMING SAFETY OADS BUNNZNG AIID STABTiNG OF LARGEST HON-CLASS IE LOAD BUS VOLTP GES (Grid at 2 g Kv)

REQUIRED CASH 2 'CAS" 13 4'us s ~

' ~ < ~

A'"'KV Nol'1E. 8 4 Bus A~~ 3203 3474' 7 4I:V Bus B~ NONE 4 3go6 4kà Bus B-+ 32o4 3968 4 2 480V LC A 393 4zo 48OV LC B 4co 480V LC C NONE 48ov LC D 4 6 48ov:.cc A '88 44 48ov I.ICC B 40ov I:cc c NOPE 4

• High side of current limiting reactor

>>'Low-side of current 1initing reactor