ML20092A692

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Forwards Analysis & Technical Justification Supporting Request for Enforcement Discretion Re post-mod Operability Tests
ML20092A692
Person / Time
Site: Oconee  Duke energy icon.png
Issue date: 08/31/1995
From: Hampton J
DUKE POWER CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9509110154
Download: ML20092A692 (5)
v • d • e


Text

11 I Duke Ibuvr Company J.W HAwmn

, (konce %xtrar Sae Vice hesident PO ika HD (M1MS3D9 Office

!qca, $C2179 (801M515fMax DUKEPOWER August 31,1995 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Subject:

Oconee Nuclear Station Docket Nos. 50-269,-270,-287 Notice of Enforcement Discretion (NOED) Request Oconee Units 1,2, and 3 Keowee Modification Implementation

Dear Sir:

Attached is the analysis and technicaljustification supporting the Oconee Units 1,2, and 3 request for enforcement discretion of 8/31/95. Enforcement discretion is requested due to problems with post-modification operability tests associated with the recently approved Keowee modification. Duke requests that the 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> allowed for placing the units in hot shutdown be extended to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to allow adequate time for an orderly shutdown of all three nuclear units. We believe this discretionary enforcement is in the best interest of nuclear safety. Technical Specification action statement 3.7.3 requires all three Oconee Units to be in hot shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, thus your prompt action is necessary and is appreciated.

We will keep you infonned regarding our progress in implementing the modification and the results of l

our work practice investigation through normal communication channels.

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If you require further information, please contact J. Ed Burchfield at (803) 885-3292.

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l Very Truly Yours,

/

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l. W. Ilarnpton, Site Vice President Oconee Nuclear Site Attachments 9509110154 DR 950831 ADDCK 05000269 j ( ,

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xc: L. A. Wiens, ONRR Project Manager S. D. Ebneter Regional Administer, Region 11 P. E. Ilarmon Senior Resident Inspector Max Botavia DIIEC

DUKE POWER COMPANY OCONEE NUCLEAR STATION ATTACIIMENT 1 DISCRETIONARY ENFORCEMENT REQUEST Oconee Plan:

1. As of 22:01 on 8/31/95, ONS will exceed the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> LCO associated with Technical Specification 3.7.2(a)(1). This specification was entered at 22:01 on 8/28/95 to implement a modification to the Keowee overhead emergency power path. Technical Specification 3.7.3 requires the units to be placed in hot shutdown within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> when the requirements of Technical Specification 3.7.2 are not met.
2. Begin preparations for an orderly shutdown of the three Oconee units at 22:01 on 8/31/95.
3. Pursue a notice of enforcement discretion (NOED) in order to allow an orderly shutdown of all three units. The NOED requests 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to achieve hot shutdown for all three units. Duke intends to begin preparations for shutting down the first unit once the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> LCO is exceeded.

Although shutting down 3 units within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> is achievable, Duke believes that a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> time period to place all three units in hot shutdown will minimize time pressures on the operating staff.

NOED request:

1. Technical Specification that will be violated:

Technical Specification 3.7.3 - Auxiliary Electrical Systems Extend the '..12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />...' requirement to be in hot shutdown to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

2. The circumstances surrounding the situation which requires the NOED:

During the installation of the recently approved Keowee modification, potential concerns regarding work practice problems were identified. Implementation of the modification was halted at approximately 14:00 on 8/30/95 in order to review these concerns and ensure that the modification was being successfully implemented. The ONS PORC was convened at 16:30 on 8/30/95 and approved the investigation and corrective actions necessary to resume work. After carefully evaluating the work practices, work was restarted at approximately 24:00 on 8/30/95.

This delay reduced the probability that the modification could be completed within the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> LCO. Therefore, actions were initiated to restore the overhead power path to an operable status within the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> LCO. Ilowever, problems were identified by the post-maintenance test and efforts are in progress to correct the problems. These efforts will not be completed within the

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72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> LCO and shutdown of all three Oconee units will be required by Technical Specification 3.7.3. )

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3. The safety basis for the NOED request:

The safety basis for the NOED request is a reduction in operator burden associated with shutting down three nuclear units within a 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> period. Although ONS believes the operating staff can safely shut down the units within this time period, the need to place additional time pressures on the operating staffis not warranted based on the negligible impact on plant safety associated with extending the shutdown period by 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. Extending the LCO for Tech Spec 3.7.3 by 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> will minimize time pressures on the operating staff without a decrease in plant safety. Prior to commencing with the unit shutdowns, a Lee Combustion Turbine will be started and available to energize the standby buses.

4. No significant hazards consideration / Safety Evaluation:

Duke Power Company (Duke) has made the determination that this request involves a No Significant liazards Consideration. This ensures that operation of the facility in accordance with this request would not:

(l)

Involve a significant increase in the nrobability or conseauences of an accident nreviously evaluated:

Each accident analysis addressed within the Oconee Final Safety Analysis Report (FSAR) has been examined with respect to the proposed request. The probability of any Design Basis Accident (DBA) is not significantly increased by the proposed request due to the fact that the identified cause in the FSAR accidents is not impacted. The reliability of the emergency power path and the failure rate of the Oconee AC power system is not significantly impacted by the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> extension of the hot shutdown requirement. In addition, a Lee Combustion Turbine will be started and available to energize the standby buses. This provides an additional source of emergency power fbr Oconee. Since the AC power failure rate is not significantly impacted and a Lee Gas Turbine will be started and available to energize the standby buses, the consequences of any DBA are within the bounds of the FSAR analyses. In addition, the proposed request does not change the methods of analysis discussed in the FSAR.

(2) Create the possibility of a new or different kind of accident from any kind of accident previously evaluated:

The proposed request extends the shutdown requirement of Technical Specification 3.7.3. This change does not alter the plant safety features or the method of operation at ONS. Therefore, extending the shutdown requirement for Oconee will not create any new or different failure modes which are not bounded by previously evaluated accidents.

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. i (3) Involve a significant reduction in a margin of safety. I l

The design basis of the auxiliary electrical systems is to supply the required ES loads of one Oconee unit and the safe shutdown loads of the other two Oconee units. Either the underground power path or a Lee Combustion Turbine is adequate to ensure operability of the ES loads during the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> extension of the hot shutdown requirement. The reliability of the emergency l power path and the failure rate of the Oconee AC power system is not significantly impacted by the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> extension of the hot shutdown requirement The proposed request does not impact the mitigation of any of the accidents analyzed in the FSAR. Therefore, there is not a significant reduction in the margin of safety associated with the proposed amendment.

Duke has concluded, based on the above, that there are no significant hazards considerations involved in this request.

5. Environmental impact statement:

No environmental impact analysis is necessary due to the fact that this request does not involve a significant hazards consideration, a significant change in the types / amounts of effluents that may be released offsite, or a significant increase in the individual / cumulative occupational radiation exposure.

6. Proposed compensatory action:
1. A I.ce Combustion Turbine will be started and available to energize the standby buses to ensure an additional source of emergency power.
2. No planned testing or maintenance will be conducted on the SSF or the switchyard until the LCO is exited.
3. All unnecessary safety-related work has been suspended.
4. All restoration activities are progressing on a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> work schedule.
5. Continuous management oversight of the modification will continue until the LCO is exited.
7. Justification of the duration of the noncompliance:

The noncompliance will exist for 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The extension of the shutdown LCO from 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is requested to minimize operator burden associated with shutting down three nuclear plants within a twelve hour period. The Oconee PRA has been reviewed and it has been detemiined that the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> extension of the shutdown requirement of Tech Spec 3.7.3 will have a negligible impact on plant safety.

8. This matter has been reviewed and approved by Oconee's Plant Operations Review Committee.
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