ML20039B218
| ML20039B218 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 12/10/1981 |
| From: | WISCONSIN ELECTRIC POWER CO. |
| To: | |
| Shared Package | |
| ML20039B215 | List: |
| References | |
| TAC-42249, TAC-42250, TAC-47494, TAC-47495, NUDOCS 8112220431 | |
| Download: ML20039B218 (5) | |
Text
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15.3.7 AUXILIARY ELECTRICAL SYSTEMS f Applicability Applies to the availability of off-site and on-site electrical power for plant power operation and for the operation of plant auxiliaries.
Objective To define those conditions of electrical power availability necessary (1) to provide for safe Itactor operation, and (2) to provide for the continuing availability of engineered safeguards.
Specification A.I Under normal conditions neither one nor both reactors shall be made critical unless the following conditions are met:
- a. At least two 345 KV transmission lines are in service.
- b. The 345/13.8 KV and the 13.8/4.16 KV station auxiliary transformers associated with the reactor (s) to be taken critical are in service; or one 345/13.8 KV station auxiliary transformer and the associated 13.8/4.16 KV station auxiliary transformer (r) are in service with the gas turbine operating.
- c. 480 Volt buses B03 and B04 for the unit (s) to be taken critical are energized.
- d. 4160 Volt buses A03, A04, A05, and A06 for the unit (s) to be taken critical are energized.
- e. A fuel supply of 11,000 gallons is available; and both diesel gener-ators are operable.
15.3.7-1 8112220431 811210 PDR ADOCK 05000266 P PDR
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- g. Either battery DIOS or D106 is op2rable; the DC systcms associated with both D105 and D106 are operable; and four battery chargers are operable with one charger carrying the DC loads of each DC main distribution bus.
A.2 Under abnormal conditions, including Black Plant startup, one reactor may be made critical prov.3ing the following conditions are met:
- a. One 345 KV transmission line is in service; or the gas turbine is operating.
- b. The 345/13.6 KV and the 13.8/4.16 KV station auxiliary transformers 1
associated with the unit to be taken critical are in service; or the associated 13.8/4.16 KV station auxiliary transformer is in service and the gas turbine is operating.
- c. Reactor power level is limited to 50% rated power until 2 of more transmission lines are restored to service.
- d. 480 Volt buses B03 and B04 for the unit to be taken critical are
, energized. .
- e. 4160 Volt buses A03, A04, A05, and A06 for the unit to be taken critical are energized.
- f. A fuel supply of 11,000 gallons is available; and both diesel generators are operable.
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- h. Either battery D105 or D106 is operable; the DC systems associated with both DIOS and D106 are operable; and four battery chargers are operable with one charger carrying the DC loads of each DC main distribution bus.
B.1 During power operation of one or both reactors, the requirements of 15.3.7.A.1 may be modified to allow the following arragements of syst3ms and cor.ponents:
15.3.7-2 .
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- a. If the 345 KV lines are reduced to only one, any operating reactor (s) must be promptly reduced to, and limited to, 50% power. If all 345 KV lines are lost, any operating reactor (s) will be reduced to supplying its auxiliary load, until one or more 345 KV transmission lines are again available.
- b. If both 345/13.8 KV auxiliary transformers are out of service and only the gas tubine is operating, only one reactor will remain operating and it will be limited to 50% power. The second reactor will be placed in the hot shutdown condition.
- c. If the 13.8/4.16 KV auxiliary transformers are reduced to only one, the reactor associated with the out of service transformer must be placed in the hot shutdown condition.
- d. Either bus A03 or A04 may be out of service for a period not exceeding 7 days provided both diesel generators are operable and the associated diesel generator is operating and providing power to the engineered safeguard bus normally supplied by the out of service bus,
- e. One diesel generator may be inoperable for a period not exceeding 7 days provided the other diesel generator is tested daily to ensure operability and the engineered safety features associated with this diesel generator shall be operable.
- f. One of the batteries DOS or D06 may be inoperable for a period not exceeding 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> providea the other three batteries and four battery chargers remain operable with one charger carrying the DC loads of each DC main distribution bus.
- g. One of the batteries D105 or D106 may be inoperable for a period not exceeding 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> provided the other three batteries and four battery chargers remain operable with one charger carrying the DC loads of each DC main distribution bus.
Basis This two unit plant has four 345 KV transmission line interconnections. A 15.3.7-3
20 MW gas turbine generator and two 2850 KW diesel generators are installed at the plant. All of these energy sources will be utilized to provide depth and reliability of service to the Engineered Safeguards equipment through redundant station auxiliary power supply systems.
The electrical system equipment is arranged so that no single contingency can inactivate enough safeguards equipaent to jeopardize the plant safety. The 480 Volt equipment is arranged on 4 buses per unit. The 4160 Volt equipment is supplied from 6 buses per unit.
Two separate outside sources can serve either unit's low voltage station auxiliary transformer. One is a direct feed from the unit's higt voltage station auxiliary transformer and the second is from the other unit's high voltage station auxiliary transformer or the gas turbine via the 13,800 Volt system tie bus H01.
Separation is maintained in the 4160 Volt system to allow the plant auxil2ary equipment to be arranged electrically so that redundant items recei"e their power from the two different buses. For example, the safety injection pumps are supplied from the 4160 Volt buses 1-A05 and 1-A06 for Unit I and 2-A05 sad 2-A06 for Unit 2; the six service water pumps are arranged on 480 Volt buses as follows: two on bus 1-B03, one on bus 1-B04, one on bus 2-B03, and two on bus 2-B04; the four containment fans are divided between 480 Volt buses 1-B03 and 1-B04 for Unit I and 2-B03 and 2-B04 for Unit 2, and so forth. Reduncsnt valves are supplied from motor control centers 1-B32 and 1-B42 for Unit I and 2-B32 and 2-B42 for Unit 2.
The plant DC electrical system has been modified so that each of the four instrument bus power supplies has its own battery and battery chargers. One battery charger shall be in service on each battery so that the batteries will always be at full charge in anticipation of a loss-of-AC power incident. This insures that adequate DC power will be available for starting the emergency generators and other emergency uses.
The emergency generator sets are General Motors Corporation, Elector-Motive Division, Model 999-20 units rated at 2850 KW continuous, 0.8 power factor 900 RPM, 4160 volts 3 phase, 60 cycle and consume 205 gallons of fuel per hour.
15.3.7-4
O Thus, the 11,000 gallon supply in the Emergency Fuel Tank provides sufficient fuel to operate one diesel at design load for scre than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. In addition, it will be normal for Point Beach to keep one, or the equivalent of ene, bulk storage tank full at all times (55,000 gallons, which is equal to about 10 days' supply). They are each capable of providing 3050 KW for a 30 minute period. The gas turbine is capable of providing 20,000 KW.
If only one 345KV transmission line is in service to the plant switchyard, a temporary loss of this line would result in a reactor trip (s) if the reactor (s) power level were greater than 50%. Therefore, in order to maintain continuity of service and the possibility of self-sustaining operations, if only one 345KV transmission line is in service to any operating reactor (s), che power level of the affected reactor (s) will be limited to 50%.
If both 345/13.8KV station auxiliary transformers are out of service, only cne reactor will be operated. The gas turbine will be supplying power to operate the safeguards auxiliaries of the operating reactor and acts as a backup supply for the unit's normal auxiliaries. Therefore, to prevent overloading the gas turbine in the event of a reactor trip, the maximum power level for the operating reactor will be limited to 50%. These conservative limits are set te improve transmission system reliability only and are not dictated by safety system requirements.
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References FSAR Section S i
15.3.7-5 i