ML20082L824

Proposed Tech Spec Table 3.3-4 Re Station Blackout,Loss of Voltage,Degraded Voltage,Trip Setpoints & Allowable Values

ML20082L824
Person / Time
Site:	North Anna
Issue date:	08/29/1991
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML20082L817	List: ML20082L815 ML20082L824
References
NUDOCS 9109040382
Download: ML20082L824 (6)

Text

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t Dochet Nos. 338 & 339 Serial No.91-506.

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Attachment Pg 6 /11-i i

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I PROPOSED CHANGES TO

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- NORTH ANNA POWER STATION-TECHNICAL SPECIFICATION 3/4.3.2 l

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1 FINAL COPY r

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i i-Virginia Electric and Power Company 91090403e2 910829 DR ADOCK 05000338 p -

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TABLE 3.3-4 (continued) 5 ENGINEERED SAFETY FEATUP.E ACTUATION SYSTEM c-INSTRUMENTATION TRIP SETPOINTS Z

R FUNCTIONAL UN T TRIP SETPOINT -

ALLOWABLEVAL* ES d

m 6.

AUylL!ARY FEEDWATER PUMP START a.

Manual N. A.

N. A.

b. Automatic Actuation Logic N. A.

N. A.

c.

Steam Generato Water Level 218% of narrow range 217% of narrow range W

Low. Low instrument span each instrument span each

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steam generator steam generator Q

d.

S. l.

See 1 above (all S.I. Setpoints) e.

Station Blackout 22392 volts on Transfer Bus 22184 volts on Transfer Bus l

f.

Trip of Ma!n Feed Pump N. A.

N. A.

7. LOSSOFPOWER

a. 4160 Volt Emergency Bus Undervoltage 3080 13 volts with a time 22989 volts with a time delay y

(Loss of Voltage) delay of 2.0 0.5 seconc^,

of s3.0 seconds e

b. 4160 Volt Emergency Bus Undervoltage 3746 7 volts with a time 23688 volts with a iime delay 3

(Degraded Voltage) delay of 5616 seconds of 563 seconds Q3 z9

4 ZO W

2>j TABLE 3.3-4 (continued)

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fJralBEERED SAFETY FEATURE ACTUATION SYSTEM E

INSTRUMENTATION TRIP SETPOINTS a

to FUNCTIONAL UNTT TRIP SETPOINT ALLOWABLE VitUES l

6.

AUXILIARY FEEDWATER PUMP START a.

Manual N. A.

N. A.

b. Automatic Actuation Logic N. A.

N. A.

c. Steam Generator Water Level 218% of narrow range 217% of narrow range y

Low-Low instrument span each instrument span each g

steam generator steam generator d.

S. I.

See 1 above (all S.I. Setpoints) e.

Station Blackout 22392 volts on Transfer Bus 22184 volts on Transfer Bus l

f.

Trip of Main Feed Pump N. A.

N. A.

7. LOSSOFPCVER y

a.

4160 Volt Emergency Bus Undervoltage 3080 113 volts with a time 22989 volts with a time delay 3

(Loss of Voltage) delay of 2.010.5 seconds of 53.0 seconds

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b. 4160 Volt Emergency Bus Undervoltage 3746 7 volts with a time 23688 volts with a time delay e

(Degraded Voltage) delay of 5616 seconds of s63 seconds R

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l Dochet Nos. 338 & 339 l

Serial No. 91506 Attachment Pg 9 /11 SECTION 3 PROPOSED CHANGES TO NORTH ANNA POWER STATION TECHNICAL SPECIFICATION 3/4.3.2 UNITS 1 AND 2 DETERMINATION OF NO SIGNIFICANT HAZARDS (10 CFR 50.92 EVALUATION) l l

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Virginia Electric and Power Company

Dockot flos. 333 & 339 sonal No 91500 Attachmont Pg 10 /11 S1GBlFICANT HAZA11RS CQRSIDJiBAILORS We have reviewed the proposed changes to Technical Specification 3/4.3.2 Table 3.3-4 Items 6.0,7.a and 7.b against the criteria of 10 CFR 50.92 and found that the proposed changes do not involve a significant hazards consideration Specifically, the proposed modifications change the Trips Setpoint and A!!owable Values in item 6.0 from abstract percentages of bus voltage to actual voltage values. Therefore, these modifications do not, in fact, alier item 6 e but are only of an administrative nature intended to promote clarity and ease of use of the specification.

The revised Trip Setpoints and Allowable Values for item 7.a and 7.b of Technical Epecifications Table 3.3 4 have been revised to afford maximum protection for the Class 1E electrical components from loss of voltage or degraded voltage conditions while minimizing the probabihty of disconnecting from the offsite power source during short term system voltage transients. The revised values are consistent with the regulatory basis for the Loss of Power and Degraded Voltage protection and the North Anna Units 1 and 2 Loss of Offsite Power (GDC-17) analysis while providing additional operc*g margins for future electrical loads.

Operation of the North Anna Power Station Units 1 and 2 in accordance with these proposed modifications to items 6.e, i.a and 7.b will not:

1. Involve a significant increase in the probability of occurrence or consequences of any accident or malfunction of equipment which is important to safety and which has been eva uated in the UFSAR. The change to item 6.0 only affects the nomenclature of the Trip Setpoints and Allowable Value e. The changes to items 7.a and 7.b, Trip Setpoints and the Allowable Values, will ensure undervoltage protection to the safety related equipment and conform to the Loss of Offsite Power analysis. The assumptions used in the accident analysis require undervoltage protection to be actuated before voltage on the buses droos below e given value.

The Techr 1 Specification instrument trip 1

setpoints are derived from this value with vded conservatisms, The Trip Setpoints are at least as restrictive as the current requirements and the Allonable Vntues define actual measured bus voltages required by current Loss of Offsite Power analyses to assure that ESF Operability has been maintained. Therefore, the proposed changes will not increase the probability or consequences of an accident previously evaluated.

2. Create the possibihty of a new or different type of accident from those previously evaluated in the safety analysis report. The change to item 6.e only affects the nomenclature of the Trip Setpoints and Allowable Values The changes to items 7.a and 7.b, Trip Setpoints and the Allowable Values, will ensure undervoltage protection to the safety related equipment and conform to the Loss of Offsite Power analysis. The assumptions used in the accident analysis j

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Dochet Nos. 338 & 339 snrial No. 91506

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Attachment P 11/11 i

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require undervoitage protection to be actuated before voltage on the' buses i

drops below a given value.

The Technical Specification instrument trip setpoints are derived from this value with added conservatisms. The Trip Setpoints are at least as restrictive as the current requirements and the Allowable Values defino actual measured bus voltages required by current Loss of Offsite Power analyses to assure that ESF Operability has been maintained. Therefore, the proposed cht.ges will not create the possibility of a i

new or different kind of accident previously evaluated.

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3. Involve a significant reduction in the margin of nafety. The change to item 6.e only affects the comen :lature of the Trip Sotpoints and Allowable Values, The changes to items 7.a-ind 7.b Trip Setpoints and the Allowable Values, will ensure undervoltage protection to the safety related equipment and conform to the Loss of Offsite Power analysis. The assumptions used in the accident I

analysis require undervoltage protection to be actuated before voltage on the buses drops below a given value. The Technical Specification instrument trip.

i setpoints are derived from this value with added conservatisms. The Trip l

Setpoints are at least as restrictive as the current requirements and the Allowable Values define actual measured bus voltages required by current Loss of Offsite Power analyses to assure that ESF Operability has been I

mair,tained. Therefore, the accident analysis assumptions remain bounding and cafety margins remain unchanged.

l Therefore, pursuant to 10 CFR 50.92, based on '

lbove consic' <ation, it has beun

- determined that the changes to Technical Specificm.on 3/4.3.2 TABLE 3.3 4 Items 6.e, l

7.a and 7.b will not involve a significant hazards consideration.

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