ML20134J664

Proposed Tech Specs Pages 3.12-1,3.12-2 & 3.12-3 Re 115 Kv Offsite Power Requirements

ML20134J664
Person / Time
Site:	Maine Yankee
Issue date:	02/07/1997
From:	Maine Yankee
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ML20134J659	List: ML20134J655 ML20134J664
References
NUDOCS 9702120243
Download: ML20134J664 (4)

Text

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8 ATTACHMENT B Revised Technical Specification Pages 3.12-1, 3.12-2. and 3.12-3 9702120243 970207 PDR ADOCK 05000309 P PDR

a 3.12. STATION SERVICE POWER Aeolicability:

Applies to station service electrical power system.

Obiectives:

To assure an adequate supply of electrical power during station operation.

Soecification:

A. The following equipme.it must be operable whenever the reactor coolant system temperature and pressure exceed 210*F and 400 psig.  !

1. One 115 kV incoming line in service.

2. Diesel generator DG-1A operable; 4160v emergency bus 5. 480v emergency bus 7 and d-c distribution cabinet 1 in service. ,

or Diesel generator DG-1B operable; 4160v emergency bus 6. 480v emergency bus 8. and d-c distribution cabinet 3 in service.

3. 18.300 gallons of diesel fuel oil in the fuel oil tanks.

Remedial Action: Restore required power supply limiting condition within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.

B. The following equipment must be operable whenever the reactor is critical, j l 1. Both 115 kV incoming lines in service.

2. Diesel generator DG-1A operable; 4160v emergency bus 5. 480v emergency bus 7. and d-c distribution cabinet 1 in service.

3. Diesel generator DG-1B operable: 4160v emergency bus 6, 480v  !

emergency bus 8. and d-c distribution cabinet 3 in service.

4. 28,800 gallons of diesel fuel oil in the fuel oil tanks.

Remedial Action:

1. If one 115 kV incoming line becomes inoperable, restore it to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.

2. If both 115 kV incoming lines become inoperable, restore one to operable status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

3. If either diesel generator or its associated emergency buses or d-c  !

l distribution cabinet becomes inoperable, within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> determine the operable diesel generator is not inoperable due to common cause failure or within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> test the operable diesel generator in  ;

accordance with Specification 4.5.A.1. The inoperable equipment  !

shall be restored to the operable status within seven days.

l 4 If one 115 kV incoming line and either diesel generator or its i associated emergency buses or dc distribution cabinet are not  !

l operable, restore the inoperable 115 kV line or the diesel generator (or its associated emergency buses or dc distribution cabinet) within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

5. If both diesel generators or their associated emergency buses or d-c distribution cabinets are not operable, restore one diesel generator (or its associated emergency buses or d-c distribution cabinet) to operable status within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

Amendment No. 65. M 6. M O 3.12-1

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6. If the diesel fuel oil level in the fuel oil tanks is less than 28.800 gallons but greater than 24.700 gallons, restore the fuel oil level within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.

C. Under accident conditions, the automatically connected load to either diesel generator shall not exceed the 2000 hour0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> rating of 2850 KW.

Basis.

l Specification A assures that an emergency power source is operable whenever the reactor coolant system is above the specified pressure and temperature limit.

It recognizes the decreased consequences of a loss of coolant accident if the reactor is subcritical.

The fuel requirement for Specification A of 18.300 gallons is made up as follows:

A. 16.637 gallons is the amount that will be required for the maximum expected engineered safeguards load for the maximum resupply time of 4 days. I B. 10 percent of the above as a contingency for any non-enginerred safeguard requirement during this period.

Specification B assures the operability of power to the engineered safeguards equipment that is necessary when the reactor is critical. If the loss of one of the 115 kV incoming lines occurs, a period of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of operation is permitted while the situation is being assessed and full redundancy is being restored. If the loss of both 115 kV incoming lines occurs, a period of 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of operation is permitted while the situation is being assessed and one of the 115 kV incoming lines is being restored. Following the restoration of this line, the remaining portion of the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> remedial action time is permitted to restore full redundance, as described above. If the loss of a diesel generator or its associated emergency buses or d-c distribution cabinet occurs, a period of seven

, days of operation is permitted while the situation is being assessed and full redundancy is being restored. These time periods are justified because adequate sources of power remain available for the operation of the engineered safeguards equipment.

, The time period of 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> for restoring either the inoperable 115 kV incoming line or an inoperable diesel generator when both are inoperable takes into account the capacity and capability of the remaining AC sources, a reasonable i time for repairs. and the low probability of a design basis accident occurring '

during this period. It recognizes that there are risks involved with performing  !

a shutdown in a degraded condition that are balanced against the risks of remaining at power to perform repairs. Following the restoration of either the diesel generator or the 115 kV incoming line to operable status, the remaining portion of the respective remedial action time is permitted to restore full redundancy as described above.

With DG-1A and DG-1B inoperable, there are no remaining standby AC sources.

Thus, with an assumed loss of offsite electrical power, insufficient standby AC ,

sources are available to power the minimum required ESF functions. Since the l offsite electrical power system is the only source of AC power for this level of i degradation. the risk associated with continued operation for a short time could

be less than that associated with an immediate controlled shutdown (the immediate l shutdown could cause grid instability, which could result in a total loss of AC power). Since any inadvertent generator trip could also result in a total loss of offsite AC power, however, the time allowed for continued operation is restricted to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The intent is to avoid the risk associated with an immediate controlled shutdown and to minimize the risk associated with this level of degradation.

Amendment No. 65. 466. M O 3.12-2 l

, The fuel requirement for Specification B of 28,800 gallons is made up as follows:

A. 26.182 gallons is the amount that will be required for the maximum expected engineered safeguards load for a period of seven days:

B. 10 percent of the above as a contingency for any non-engineered I safeguard requirement during this period.

C. Fuel oil tank level is restricted to fuel oil level reductions that maintain at least a 6 day supply. This restriction allows sufficient time for obtaining the requisite replacement volume and performing the fuel analyses required prior to addition of fuel oil to the tank. A period of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> is considered sufficient to complete restoration of the required level prior to declaring DGs inoperable. This period is acceptable based on the remaining capacity (greater than 6 days), the fact that procedures will be initiated to obtain replenishment, and the low probability of an event during this brief period.

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l Amendment No. 65. M 6. MO 3.12-3