ML20112C185

Proposed Change 105 to Tech Specs Limiting Conditions for Operation & Surveillance Requirements for Power Protection Equipment Added to Reactor Protection Sys During 1983 Refueling Outage

ML20112C185
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	03/04/1985
From:	VERMONT YANKEE NUCLEAR POWER CORP.
To:
Shared Package
ML20112C161	List: ML20112C158 ML20112C185
References
NUDOCS 8503210346
Download: ML20112C185 (7)

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3.10 LIMITING CONDITIONS FOR OPERATION' 4.'10 SURVEILLANCE HEQUIREMENTS

3. Emergency Buses' 3. Emerrency Buses The emergency 4160 volt Buses 3 and 4..and The emergency 4160 volt buses'and 480 volt 480 volt Buses 8 and 9 shall be energized'and buses shall be checked daily. ,

operable. .

4. Off-Site Power 4. Off-Site Power

a. At least one off-site transmission line The status of the off-site power sources and at least one start-up transformer in shall be checked daily, service. ,

b. One of the following additional sources of delayed access power:

The main stepup transformer and unit auxiliary transformer available and capable of supplying power to the emergency 4160 volt buses or, The 4160 volt tie line to Vernon flydro-Electric Station capable of supplying power to either of the two emergency 4160 volt buses.

5, 480 V Uninterruptible Power Systems S. 480 V Uninterruptible Power Systems Both 480 V Uninterruptible Power Systems a. The requirements of Specifications (UPS-1A, UPS-1B) and their respective Motor 4.lO.A.2(a) and (b) shall be satisfied Control Centers (89A, 89B) shall be energized for each 480 V Uninterruptible Power and operable. System battery bank.

b. Each Uninterruptible Power System

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• 850'.1210346 850304 performance discharge test every 5 years.

PDR ADOCK 05000271 P PDR l Amendment No.-26 1/S e

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3.10 1.IMITING CONDITIONS FOR OPERATION 4.10 SURVEl!.t.ANCE REQUIREMENTS

c. Each 480 V Uninterrupt.ible Power System shall be checked daily,

d. 480 V Motor Control Centers 89A and 89B shall be checked daily.

c. Once per operating cycle, the actual cotiditions under which the 480 V Uninterruptible Power Systems are required will be simulated and a test conducted to demonstrate equipment performance.

> i 6. Reactor Protection System Power Protection 6. Reactor Protection System Power Protection l

,' Two RPS power protection panels for each Once per operating cycle, the operability of 1 inservice RPS MG set or alternate power each overvoltage, undervoltage, and l source shall be operable. underfrequency protective device shall be i demonstrated by the performance of an instrument channel calibration test.

Settings shall be verified tc be in accorde.nce with Table 4.10.1.

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3.10 LIMITING CONDITIO*fS FOR OPERATION 4.10 SURVEILLANCE REQUIREMENTS

3. Off-Site Power 3. Off-Site Power

a. From and after the date that both startup a. When it is determined that one of the transformers and one diesel generator or diesel generators or associated-buses is associated buses-ete made or found to be inoperable, the requirements of inoperable for any reason, reactor operation Specification 4.5.H.1 shall be satisfied.

may continue provided the requirements of Specification 3.5.H.1 are satisfied.

b. From ano after the date that both b. When it is determined that both delayed delayed-access of f-site power sources become access off-site power sources are: ,

unavailable, reactor operation may continue unavailable, both diesel generators, for seven days provided both emergency diesel associated buses and all low pressure generators, associated buses, and all low core and containment cooling systems pressure core and containment cooling systems shall be demonstrated to be operaole are operable, inunediately and daily thereaf ter.

4. 480 V Uninterruptible Power Systems 4. 480 V Uninterruptible Power System From and after the date that one When it is determined that one -

Uninterruptible Power System or its Uninterruptible Power System or its associated Motor Control Center are made or associat,ed Motor Control Center is found to be inoperable for any reason, the inoperable, the requirements of. Specification requirements of Specification 3.5.A.4 shall 4.5.A.4 shall be satisfied, be satistied.

5. RPS Protection System Power Protection From and after the date that one or more of th RPS power protection panels on an inservice RPS MG set or an alternate power

source is made or found to be inoperable, the

.i panel shall be restored to operable status j within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. If the panel cannot be

restored to operable status within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, j it shall be tripped.

Amendment No. 26 Ill w __ _ _ _ _ _ .

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3.10 LIMITING CONDITIONS FOR OPERATION 4.10 ' SURVEILLANCE REQUIREMENTS C. Diesel Puel C. Diesel Fuel There shall be a minimum of 25,000 1. The quantity of diesel generator usable gallons of diesel fuel in the fuel shall be logged weekly and diesel fuel oil storage tank. atter each operation of the unit.

2. Once a month a sample of diesel fuel shall be taken and checked for quality. The quality shall be within the applicable limits specified on Table I of ASTM D915-68 and logged.

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Reactor Protection System Power Protection Setyoint Parameter Panel A1 A2, Bl a_BJ, Panel C1 and_C2 Overvoltage 1 125.5 volts 1 125.5 volts Overvoltage Time Delay s 0.35 seconds s 4 seconds Undervoltage 1 111 volts 2 111 volts Undervoltage Time Delay 1 0.35 seconds 1 4.0 seconds Underfrequency 2 56.5 Hz g 56.5 Itz Underf requency Time , 31ay 1 0.35 seconds s 0.35 seconds 177b

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. AUXILIARY FLECTRIC POWER SYSTEMS LA.

The objective of this Specification is to assure that adequate power will be available to operate the emergency safeguards equipment. Adequate power can be provided by any one of the following sources: either of the startup transformers, backfeed through the main transformer, the 4160 volt line f rom the Vernon liydroelectric Station or either of the two diesel generators. The backf eed through the nwin transformer and 4160 volt Vernon - ~

line are both delayed access off-site power sources, Backfeeding through the main transformer can be accomplished by disconnecting the main generator from the main transformer and energizing the auxiliary transformer from the 345 kV switchyard through the main transformer. The thre required to perform this disconnectioni is approximately six hours. The 4160 volt line f rom the Vernon Ilydroelectric Station can be connected to either of the two emergency buses within seconds by simple manual switching operation in the Main Control Room.

Two 480 V Uninterruptible Power Systems, each consisting of a battery bank, battery charger, and a sold state inverter, supply power to the LPCIS valves via designated Motor Control Centers. The 480 V Unin;crruptible Power Systems are redundant and independent of any on- site power sources.

This Specification assures that at least two off-site and two on-site power sources, and both 480 V Uninterruptible Power Systems will be available before the reactor is taken beyond "just critical" testing. In addition to assuring power source availability, all of the associated switchgear must be operable as specified to assure that the emergency cooling equipment can be operated, if required, from the power sources.

Station service power is supplied to the stat ion through either the unit auxiliary transformer or the startup transformers. In order to start up the station, at least one startup transformer is required to supply the station auxiliary load. After the unit is synchronized to the system, the unit auxiliary transformer carries the station auxiliary load, except for the station cooling tower loads which are always supplied by one of the startup transformers. The station cooling tower loads are not required to perform an engineered safety feature function in the event of an accident; therefore, an alternate source of power is not essential. Normally one startup transformer supplies 4160 volt Buses 1 and 3, and the other supplies Buses 2 and 4; bowever, the two startup transformers are designed with adequate capacity such that, should one become or be umde inoperable, temporary connections can be made to supply the total station load (less the cooling towers) from the other startup transformer.

I Amendment No. 58 178

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A battery charger is supplied for each battery. In addition,'the two 125 volt station batteries and.the two 24:

. . volt ECCS instrumentation batteries each have a spare charger available. Since one space 24 volt and one 125 s volt charger are available, one battery' charger can be allowed out of service for maintenance and repairs.

Power for the Reactor Protection System is supplied by 120 V ac motor generators with an alternate supply from MCC-8B. 1Dc) redundant. Class IE, seismically qualified power protection panels are connected in series with each ac powet source. These panels provide overvoltage, undervoltage, and underfrequency protection for the system. Setpoints are chosen to be' consistent with the input power requirements of the equipment connected to the bus.

B. ' Adequate power is available to operate the emergency safeguards equipment from either startup transformer or for minimum engineered safety features.from either of the emergency diesel generators. .Therefore, reactor operation is permitted for up to seven days with both delayed-access of f-site power sources . lost.

Each of the diesel generator units is, capable of supplying 100 percent of the minimum emergency loads required under postulated design basis accident conditions. Each unit is physically and electrically independent of the-other and of any off-site power source. Therefore, one diesel generator can be allowed out of service for.a period of seven days without jeopardizing the safety of the station.

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