ML20126G032

Forwards Revised Response to Question 430.23 Re Adequacy of Motor Starting Voltage Ratings.Test Results Show That Operating or Starting Motors w/75% Vs 80% Nominal Voltage at Motor Terminals Justified

ML20126G032
Person / Time
Site:	Beaver Valley
Issue date:	06/12/1985
From:	Carey J DUQUESNE LIGHT CO.
To:	Knighton G Office of Nuclear Reactor Regulation
References
2NRC-5-090, 2NRC-5-90, NUDOCS 8506180043
Download: ML20126G032 (4)

Text

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2NRC-5-090 June 12, 1985

'Af (412) 787-5141 Robinson aza B Idi g 2 Suite 210 Pittsburgh, PA 15205 United States Nuclear Regulatory Commission Washington, DC 20555 ATTENTION:

Mr. George W. Knighton, Chief Licensing Branch 3 Of fice of Nuclear Reactor Regulation

SUBJECT:

Beaver Valley Power Station - Unit No. 2 Docket No. 50-412 Revised Response to Question 430.23 Gentlemen:

Attached is a revised response wh ich demonstrates the adequacy of motor starting voltage ratings used at BVPS-2.

DUQUESNE LIGHT COMPANY l

By G Vf-W J.VS.~ Carey

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Vice President GLB/wjs Attachment l

i cc:

Mr. R. DeYoung, Director (3) (w/a) l Mr. B. K. Singh, Project Manager (w/a) l Mr. G. Walton, NRC Resident Inspector (w/a) l INPO Records Center (w/a)

NkC Document Control Desk (w/a)

SUBSQRIBED AND SWOP TO BEFORE ME THIS A dj(. DAY OF h4xo 1985.

8506180043 g 6 12

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d-PDR ADOCK PDR A

Notary Public l

ANITA ELAINE REITER, NOTARY PUBLIC ROBINSON TOWNSHIP, ALLEGHENY COUNTY f

MY COMMISSION EXP!RES OCTOBER 20,1986

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Uni,ted States Nuclear Regulatory Commission Mr. George W. Knighton, Chief Revised Response to Question 430.23 Page 2 COMMONWEALTH OF PENNSYLVANIA )

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COUNTY OF ALLEGHENY

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On this

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//[I, before ine, a Notary Public in and for said Cdonwealth and County, personally appeared E. J. Woolever, who being duly sworn, deposed and said that (1) he is Vice President of Duquesne Light, (2) he is duly authorized to execute and file the foregoing Submittal.on. behalf of said Company, and (3) the statements set forth irJ the Submittal are true and correct to the best of his knowledge.

,a s A Notary Public ANITA E!AINE REITER, NOTARY PUBLIC ROBINSON TOWNSHIP, ALLEGHENY COUNTY MY COMMISSION EX*lRES OCTOBER 20,1986 e

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Qu stion 430.23 (SRP 8.3.1)

Section 8.3.1.1.16 of the FSAR indicates that safety-related motors are designed with the capability of accelerating the driven equipment to its rated speed with 80 percent of motor naneplate voltage applied at the saotor terminals.

Section 8.3.1.1.15 of the FSAR indicates that the design of each diesel generator unit is such that at no time during the loading sequence does the voltage decrease to less than 75 percent of 4

nominal.

Justify operating or starting motors with 75 versus 80 percent of nominal voltage at the motor terminals.

Response

Table 430.23-1 is a summary of diesel generator test results which,

although not planned fo r that purpose, show that voltage dips below the specified starting voltage of a motor have an insignificant affect.

Cases IA. through IE were taken from the sequential load test of the BVPS-2 diesel generators and are designed to envelop the actual diesel generator loading schedule.

The results clearly demonstrate that a 1750 HP motor, 40 percent larger than the largest motor powered by the BVPS-2 diesels, with a minimum starting volt age rating of 90 percent, starts quickly and the diesel generator recovers well within 60 percent of the load step.

These results also show that simultaneously starting two 500 HP, 80 percent motors, which is a combined load 11 percent large r than the largest automatically loaded motor powered from the BVPS-2 diesel generators, also results in successful starts and fast recovery.

Cases II and III, which are results of the motor start capability test and margin test, also clearly demonstrate the ability of motors with less conservative characteris tics to acceptably start.

Obviously, Cases IE, II, and III are more severe than those instances when the largest motor, a 1250 HP standby service water pump, is energized (note that the 900 HP service water pump loads will not be present under these scenarios). The standby service water pumps are non-Class IE loads fed from the emergency buses, and are designed to operate only upon the loss of the intake structure.

During the automatic loading ~ sequence, the standby service water pumps are blocked from starting until the automatic loading sequence of the diesel generators is complete.

Then, loading of the standby service water pumps onto the Class IE diesel generator system is by manual action only.

TAB m 430.2:-1 Partial Stamary of Diesel Generator loadirs Capability Time (Sec)

Preloal Applied Mininun Recovery Mininun Recovery Case (Note 1)

}t> tor /loal load Percent Time to 90%

Nrcent Tine to 90%

IA 1

0/0 1750lF

< 75%

<3/4sec 99.2%

m IB 5

1750HP/0 1100KW N/C E

N/C E

IC 10 1750HP/1100KW 1750tP

< 75%

< 3/4 sec 95%

< 3 see ID 20 2-1750HP/ll00KW 2600M N/C NA

%.8% < 4 see IE 30 2-1750HP/3700KW 2-500tP 81%

< 1/2 sec 96%

< 2-1/2 see II E

1750HP/2000KW 1750HP

< 75%

< 3/4 see

< 95%

< 3 see III NA 0/2119KW 1750HP

< 75%

<3/4sec

< 95%

< 3-1/4 see IUIES:

1) After diesel generator initially reaches rated frequency arti voltage

2) N/C - No charge

3) NA - Not applicable

4) Each 1750le notor is a 90% voltq!;e start notor

5) Each 500HP motor is an 80% voltage start notor