ML20138G340

Amend 157 to License DPR-36,revising TS 3.12, Station Svc Power, to Require Both 115 Kv Power Circuits to Be Operable When Reactor Critical

ML20138G340
Person / Time
Site:	Maine Yankee
Issue date:	05/02/1997
From:	Milano P NRC (Affiliation Not Assigned)
To:
Shared Package
ML20138G311	List: ML20138G308 ML20138G340 ML20138G354
References
NUDOCS 9705060267
Download: ML20138G340 (6)

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Uro g i UNITED STATES g

j NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20066 4 001

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MAINE YANKEE ATOMIC POWER COMPANY DOCKET N0. 50-309 MAINE YANKEE ATOMIC POWER STATION AMENDMENT TO FACILITY OPERATING LICENSE Amendment No.157 License'No. DPR-36

1. The Nuclear Regulatory Commission (the Comission) has found that:

A. The application for amendment by Maine Yankee Atomic Power Company (the licensee) dated February 7, 1997, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (1) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in acccrdance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.

P. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.B(6)(b) of Facility Operating License No. DPR-36 is hereby amended to read as follows:

j 9705060267 970502 PDR ADOCK 05000309 P PDR n I

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(b) Technical Soecifications The Technical Specifications contained in Appendix A, as revised through Amendment No.157, are hereby incorporated in the license. The licensee shall operate the facility in accordance with the Technical Specifications.

3. This license amendment is effective as of its date of issuance, to be implemented within 30 days of issuance.

FOR THE NUCLEAR REGULATORY COMMISSION

%o Patrick D. Milano, Acting Director Project Directorate I-3 Division of Reactor Projects - I/II Office of Nuclear Reactor Regulation

Attachment:

Changes to the Technical Specifications Date of Issuance: May 2, 1997 l

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I ATTACHMENT TO LICENSE AMENDMENT N0.157 FACILITY OPERATING LICENSE NO. DPR-36 DOCKET N0. 50-309 Replace the following pages of the Appendix A, Technical Specifications, with the attached pages. The revised pages are identified by Amendment number and i contain vertical lines indicating the areas of change. '

Remove Insert 3.12-1 3.12-1 3.12-2 3.12-2 3.12-3 I

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3.12 STATION SERVICE POWER Aoolicability: Applies to station service electrical power system.

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

Specification:

A. The following equipment 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 j Diesel generator DG-1B operable; 4160v emergency bus 6, 480v emergency bus 8, and d-c distribution cabinet 3 in service.

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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.

1. Both 115 kV incoming lines in service. l

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 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 3.12-1 Amendment No. 19,55,105,140,157

l generator in accordance with Specification 4.5.A.I. The -

inoperable equipment shall be restored to the operable status within seven days. l l

4. If one 115 kV incoming line and either diesel generator or its l 4

associated emergency buses or de distribution cabinet are not operable, restore the inoperable 115 kV line or the diesel g generator (or its associated emergency buses or de distribution 4 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 i d-c distribution cabinets are not operable, restore one diesel generatur (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 />. l

6. If the diesel fuel oil level in the fuel oil tanks is less than l 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:

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Specification A assures that an emergency power source is operable whenever l the reactor coolant system is above the specified pressure and temperature limit. It recognizes the decreased consequences _of a loss of coolant accident 4

if the reactor is subcritical.

l The fuel requirement for Specification A of 18,300 gallons is made up as i

follows: 1 A. 16,637 gallons is the amount that will be required for the maximum I i expected engineered safeguards load for the maximum resupply time of '

4 days.

B. 10 percent of the above as a contingency for any non-engineered 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 '

hours 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 o' power remain available for the operation of the engineered safeguards ejuipment.

3.12-2 Amendment No. 55,105,140,157

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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 l incoming line or an inoperable diesel generator when both are inoperable takes into account the capacity and capability of the remaining AC sources, a i reasonable time for repairs, and the low probability of a design basis i accident occurring during this period. It recognizes that there are risks involved with performing a shutdown in a degraded condition that are balanced i 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.

4 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 l AC sources are available to power the minimum required ESF functions. Since i the offsite electrical power system is the only source of AC power for this -

level of degradation, the risk associated with continued operation for a short time could be less than that associated with an immediate controlled shutdown (the immediate shutdown could cause grid instability, which could result in a i

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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 i associated with an immediate controlled shutdown and to minimize the risk associated with this level of degradation.

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

follows:

i A. 26,182 gallons is the amount that will be required for the maximum i expected engineered safeguards load for a period of seven days.

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

1 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 3

inoperable. This period is acceptable based on the remaining capacity (greater than 6 days), the fact that procedures will be i- initiated to obtain replenishment, and the low probability of an event during this brief period.

I 3.12-3 Amendment No. 55,105, MO,157 l

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