ML17306A477

Forwards Worse Case Loading Profile for DGs Following Forced Shutdown or Loss of Coolant Accident/Loss of Offsite Power Event in Support of 910821 Proposed TS Amends to Spec 3/4.8.1 Re Ac Sources

ML17306A477
Person / Time
Site:	Palo Verde
Issue date:	02/19/1992
From:	Conway W ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
161-04623-WFC-D, 161-4623-WFC-D, NUDOCS 9202250268
Download: ML17306A477 (13)

Text

ACCELERATED DI UTION DEMONSTPA,TION SYSTEM REGULAT ZNFORMATZON DZSTRZBUTZO1ISTEM (RZDS)

DOCKET 05000528 05000529 05000530

SUBJECT:

Forwards worse case loading profile for DGs following forced shutdown or loss of coolant accident/loss of offsite power event in support of 910821 proposed TS amends to Spec 3/4.8.1 re ac, sources.

DISTRIBUTION CODE:

A001D COPIES RECEZVED:LTR ENCL SIZE:

TITLE: OR Submittal: General Distribution ACCESSION NBR:9202250268 DOC.DATE: 92/02/19 NOTARIZED:

NO FACIL:QTN-, 50-528 Palo Verde Nuclear Station, Unit 1, Arizona Publi

'STN-50-529 Palo Verde Nuclear Station, Unit 2, Arizona Publi STN-50-530 Palo Verde Nuclear Station, Unit 3, Arizona Publi AUTH.NAME AUTHOR AFFILIATION CONWAYFW.F.

Arizona Public Service Co. (formerly Arizona Nuclear Power RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

NOTES:STANDARDIZED PLANT Standardized plant.

Standardized plant.

RECIPIENT ID CODE/NAME PD5 LA TRAMMELL,C INTERNAL: ACRS NRR/DET/ESGB NRR/DST 8E2 NRR/DST/SICB8H7 NUDOCS-ABSTRACT OGC/HDS1 RES/DSIR/EIB EXTERNAL: NRC PDR NOTES:

COPIES LTTR ENCL 1

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6 1

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1 RECIPIENT ID CODE/NAME PD5 PD THOMPSON,M NRR/DET/ECMB 7D NRR/DOEA/OTSB11 NRR/DST/SELB 7E NRR/DST/SRXB 8E OC/LEHB FILE NSIC COPIES LTTR ENCL 1

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NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE! CONTACTTHE DOCUMENT CONTROL DESK.

ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR NAMEFROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

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TOTAL NUMBER OF COPIES REQUIRED:

LTTR 27 ENCL 25

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Arizona Public Service Company P.O. BOX 53999

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PHOENIX. ARIZONA85072<999 WILLIAMF. CONWAY EXECUTIVEVICEPRESIOENT NUCLEAR 161-04623-WFC/DAF February 19, 1992 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Station P1-37 Washington, DC 20555

Reference:

Letter 161-04124-WFC/DAF, dated August 21, 1991, from W. F. Conway, APS, to U. S. Nuclear Regulatory Commission (NRC), "Proposed Technical SpeciTication Amendments to Specification 3/4.8.1, A. C. Sources"

Subject:

Palo Verde Nuclear Generating Station (PVNGS)

Units 1,2, and 3 Docket Nos. STN 50-528/529/530 Additional Information in Support of Proposed Revision to PVNGS Diesel Generator Surveillance Testing File: 92-F-005-41 9.05 92-056-026 During the NRC's review of the referenced Arizona Public Service Company (APS)

Technical.Specification amendment request, APS was requested to provide additional information.

The amendment

request, in part, would allow APS to conduct overload testing of the PVNGS diesel generators during the last two hours of a 24-hour surveillance test (performed every 18 months). Specifically, the NRC requested a copy ofthe PVNGS diesel generator kilowatt (KW) loading profile in order to continue their review of the referenced Technical Specification amendments.

Accordingly, APS has calculated the worst case (i.e., maximum) loading profile (starting and steady state loads) for PVNGS diesel generators following a forced shutdown or loss of coolant accident/loss of offsite power (LOCA/LOP) event.

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U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Page 2 161-04623-WFC/DAF February 19, 1992 The worst case diesel generator loading as a function of time is shown numerically in Table 1 and graphically in Figure 1 (see Attachments 1 and 2, respectively).

These calculations (based on Diesel Generator Loading Calculation') provide the KW and kilovoltamperes reactive (KYAR) loads for both Train A and Train B of the diesel, Of the two loading conditions, a LOCA/LOP on Train B results in the maximum transient loading and thus presents the highest KW values, which are provided in Table 1.

Figure 1 shows diesel generator KW and KYARloadings as a function of time. The plot with "a" symbols represents the KW loading, while "+" represents the KYARloading and "i" represents the maximum rated capacity of the diesel (5500 KW). At time t = 0, a motor load of 1147 KW is switched on. This produces a 1274 KW and 6245 KVARload on the generator which remains constant for 5 seconds at which time the motors reach their final speed and the starting load changes to a running load (1147 KW and 555 KVAR). At 5 seconds, a step.2 load of 654 KW is added on as a motor start load, etc.

Therefore, the KW plot is seen essentially as a stair step loading which reaches its final value of 5218 KWat t = 40 seconds.

The KWload drop at 40 seconds is due to the load connected at 35 seconds changing from a starting to a running load. The KYARloading is initially high due to the starting of a large motor load which then drops to 2642 KYAR producing a net steady state 5849 kilovoltamperes (KVA) load on the diesel generator.

The curves in Figure 1 are based on the values in Table 1. Column 1 of Table 1 marked "Time (sec)" shows one second increments from 0 to 45 seconds.

Column 2 marked "Step (KW)" shows the values from the calculation'or the LOCA/LOP event (Train B load).

The column marked "Starting Load" shows the starting KW and KYAR loads for the step load of column 2, Starting KVAis assumed to be 5 times the running KVAwith a power fa'ctor of 0.2 lagging. The column marked "Running Load" shows the total load at the steady state condition.

The 1147 KW load which was switched on at t = 0 seconds does not reach its steady state value for 5 seconds.

A power factor of 0.9 lagging is used to calculate the running load. The column marked "Starting + Running" shows the sum of starting and running loads and represents the total load on the diesel generator with the exception of the KW and KYARlosses which have not been included.

'Diesel Generator Loading Calculation, Calculation No. 13-EC-DG-200, Rev. 7.

'Diesel Generator Loading Calculation, Calculation No. 13-EC-DG-200, Rev. 7, pages 27-33.

U. S. Nuclear Regulatory Commission ATlN: Document Control Desk Page 3 161-04623-WFC/DAF February 19, 1992 The next column shows the losses which are proportional to the square of the total KVA loading.

The final column marked "Net Diesel Gen Loading" shows the net KW, KVAR, and KVAloading on the diesel including losses.

The following assumptions have been made in calculating the diesel loading profile:

1

~

The starting KVAis 5 times the running KVA.'.

The starting power factor is 0.2.'.

The running power factor is 0.9.'.

The starting KVAand power factor remain unchanged for about 4 seconds, then change to the running KVA and power factor between 4 and 5 seconds.4 5.,

All loads are induction motor loads.

6.

Losses are proportional to the square of the total KVAloading of the diesel generator.

Table 1

represents the maximum transient loading profile for the PVNGS diesel generators.

As can be seen from the results of this calculation, the maximum KW rating is not exceeded during the transient period.

The maximum calculated KVA loading (701 4 KVA) is shown to exceed the maximum KVArating (6875 KVA) by 2% during the 35 through 39 second interval, however, this assumes the entire 383 KW manual load is added to the diesel simultaneously.

This assumption, while conservative, is unrealistic as operators place these loads on as needed, typically one at a time where no overloading would occur.

The loading profile calculation'ill be incorporated into the Diesel Generator Loading Calculation'or additional information.

I

'Transient Volta e Res onse of the Diesel Generator Units Trains A and B to Postulated Emer enc

Loadin, NEI Peebles-Electrical

Products, Inc., Report No.

M018-551-1, Table 4-6.

'Paul C. Krause, Anal sis of Electrical Machine (New York: McGraw Hill Book Company, 1986), page 194.

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U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Page 4 161-04623-WFC/DAF February 19, 1992 If you have any questions, please call Michael E. Powell of my staff at (602) 340-4981.

Sincerely, WFC/DAF/daf Attachments cc:

J. B. Martin D. H. Coe A. C. Gehr A. H. Gutterman

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Attachment 1

PALO VERDE DIESEL GENERATOR LOADINGFOR LOCA/LOP TRAIN B LOAD Revised 12-23-91 To Include KYAR Losses Time sec STEP KW Startin KW Load KYAR Running Load KW KYAR Starting+Running KW KYAR Losses KW KVAR, Net Diesel Gen Loading KW KYAR KVA 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00 21.00 22.00 23.00 24.00 25.00 26.00 27.00 28.00 29.00 30.00 31.00 32.00 33.00 34.00 35.00 36.00 37.00 38.00 39.00 40.00 41.00 42.00 43.00 44.00 45.00 1147 0

0 0

0 654 0

0 0

0 903 0

0 0

0 549 0

0 0

0 544 0

0 0

0 551 0

0 0

0 414 0

0 0

0 383 0

0 0

0 0

0 0

0 0

0 1274 1274 1274 1274 1274 727 727 727 727 727 1003 1003 1003 1003 1003 610 610 610 610 610 604 604 604 604 604 612 612 612 612 612 460 460 460 460 460 426 426 426 426 426 0

0 0

0 0

0 6245 6245 6245 6245 6245 3561 3561 3561 3561 3561 4916 4916 4916 4916 4916 2989 2989 2989 2989 2989 2962 2962 2962 2962 2962 3000 3000 3000 3000 3000 2254 2254 2254 2254 2254 2085 2085 2085 2085 2085 0

0 0

0 0

0 0

0 0

0 0

1147 1147 1147 1147 1147 1801 1801 1801 1801 1801 2704 2704 2704 2704 2704 3253 3253 3253 3253 3258 3797 3797 3797 3797 3797 4348 4348 4348 4348 4348 4762 4762 4762 4762 4762 5145 5145 5145 5145 5145 5145 0

0 0

0 0

555 555 555 555 555 872 872 872 872 872 1309 1309 1309 1309 1309 1574 1574 1574 1574 1574 1838 1838 1838 1838 1838 2104 2104 2104 2104 2104 2305 2305 2305 2305 2305 2490 2490 2490 2490 2490 2490 1274 1274 1274 1274 1274 1874 1874 1874 1874 1874 2804 2804 2804 2804 2804 3314 3314 3314 3314 3314 3857 3857 3857 3857 3857 4409 4409 4409 4409 4409 4808 4808 4808 4808 4808 5188 5188 5188 5188 5188 5145 5145 5145 5145 5145 5145 6245 6245 6245 6245 6245 4116 4116 4116 4116 4116 5788 5788 5788 5788 5788 4296 4298 4298 4298 4298 4536 4536 4536 4536 4536 4838 4838 4838 4838 4838 4358 4358 4358 4358 4358 4390 4390 4390 4390 4390 2490 2490 2490 2490 2490 2490 91 91 91 91 91 46 46 46 46 46 93 93 93 93 93 66 66 66 66 66 80 80 80 80 80 96 96 96 96 96 95 95 95 95 95 104 104 104 104 104 73 73 73 73 73 73 188 188 188 188 188 95.

95.

95.

95.

95.

192 192 192 192 192 136 136 136 136 136 164 16n 164 164 164 199 199 199 199 199 195 195 195 195 195 214 214 214 214 214 151 151 151 151 151 151 1366 1366 1366 1366 1366 1920 1920 1920 1920 1920 2897 2897 2897 2897 2897 3380 3380 3380 3380 3380 3937 3937 3937 3937 3937 4505 4505 4505 4505 4505 4903 4903 4903 4903 4903 5291 5291 5291 5291 5291 5218 5218 5218 5218 5218 5218 6434 6434 6434 6434 6434 4211 4211 4211 4211 4211 5980 5980 5980 5980 5980 4435 4435 4435 4435 4435 4701 4701 4701 4701 4701 5037 5037 5037 5037 5037 4554 4554 4554 4554 4554 4605 4605 4605 4605 4605 2642 2642 2642 2642 2642 2642 6577 6577 6577 6577 6577 4628 4628 4628 4628 4628 6645 6645 6645 6645 6645 5576 5576 5576 5576 5576 6132 6132 6132 6132 6132 6758 6758 6758 6758 6758 6692 6692 6692 6692 6692 7014 7014 7014 7014 7014 58n9 5849 5849 5849 5849 5849 TPE/PVDG.WKt ASSUMPTIONS:

1. Starting KVA& PF remain unchanged for 4 seconds and change between 4 &5 sec to running values.

2. Starting KVA=S*Rated KVA

3. Starting PF=0.2 & Running PF=0.9

4. Losses are proportional to KVAsquared

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Attachment 2

PVDG Loading For LOCA/LOP Train-B Load Revised I2-23-91 To Include Losses

+~&esca 10 20 30 40 Seconds o

KW

+

KYAR o

Rated KWCapacity

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