ML20086A834
| ML20086A834 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 03/11/1994 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Ebneter S NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 94-169, NUDOCS 9507050055 | |
| Download: ML20086A834 (3) | |
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' Iw 11 '94 16:16 ItD P.2/4 ENCLOSURE dl VrnointA Ex.ecTusc aun Powen Co>&ANY H rendrow n, Vinorws4 canon March 11,1994 Mr. Stewart D. Ebneter Serial No.94-169 Regional Administrator NL&P/CSW R5 United States Nuclear Regulatory Commission Docket No. 50-339 License No. NPF-7 i
Region ll i
101 Marietta Street, N. W.
Suite 2900 Atlanta, Georgia 30323 I
Dear Mr. Ebneter:
VIRGINIA FLECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNIT 2 REQUEST FOR ENFORCEMENT DISCRET10N On March 9,1994, at 0503 hours0.00582 days <br />0.14 hours <br />8.316799e-4 weeks <br />1.913915e-4 months <br />, the Unit 2 Steam Driven Auxiliary Feedwater Pump (2-FW-P-2) was declared inoperable and the Action Statement requirement of Technical Action Specification 3.7.1.2 was entered to perform preplanned maintenance.
Statement 3.7.1.2.a requires that with one Auxiliary Feedwater Pump inoperable, restore the required Auxiliary Feedwater Pump to an OPERABLE status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
The preplanned maintenance was being performed to correct a condition which allowed water to contaminate the lubricating oil even though this condition did not render the pump inoperable. This condition was attributed to leakage past the turbine gland assembly. During the preplanned maintenance evolution, a slight misalignment of the turbine's upper casing was identified. In order to correct this misalignment, Enforcement Discretion of the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Action Statement in Technical Specification 3.7.1.2.a is being requested. The Action Statement was entered at 0503 hours0.00582 days <br />0.14 hours <br />8.316799e-4 weeks <br />1.913915e-4 months <br /> on March 9,1994 and will expire at 0503 hours0.00582 days <br />0.14 hours <br />8.316799e-4 weeks <br />1.913915e-4 months <br /> on March 12.1994. Enforcement Discretion will permit continued operation for an additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to repair and test the Auxiliary Feedwater Pump.
The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Enforcement Discretion will expire at 0503 hours0.00582 days <br />0.14 hours <br />8.316799e-4 weeks <br />1.913915e-4 months <br /> on March 13,1994.
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On March 11, 1994, during a telephone call between Virginia Electric and Power Company and the NRC, we requested Enforcement Discretion to extend the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Action Statement of Technical Specification 3.7.1.2.a by 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to complete the repair and post maintenance testing of the Steam Driven Auxiliary Feedwater Pump. The NRC verbally approved the request on March 11,1994.
SAFETY IMPACT AND POTENTIAL CONSEQUENCES Operation of the unit with the Steam Driven Auxiliary Feedwater Pump inoperable does not create an immediate threat to safety when the remaining Auxiliary Feedwater Pumps are OPERABLE. The Auxiliary Feedwater (AFW) System continues to be
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9507050055 940311 PDR ADOCK 05000339 P
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- I LP 11 '94 16:17 iLI, P. 3 '4 capable of performing its intended safety function. The design basis of the Auxiliary Feedwater System is to ensure that the Reactor Coolant System can be cooled down to less than 350 F from normal operating conditions in the event of a total loss of off-site power. This basis continues to be met.
The North Anna Individual Plant Evaluation (IPE) model includes plant specific data for the Steam Driven Auxiliary Feedwater Pump. The maintenance unavailability for this pump was conservatively adjusted to reflect a single additional outage of 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br />. The core damage frequency (CDF) from internal events was recalculated with the increased outage time to determine the sensitivity of the additional outage. The CDF incremental increase was approximately 9.0E 8/yr. This incremental increase is judged to be negligible.
No load changes are planned during AFW Pump repair activities. In addition, the following compensatory actions will be taken:
No planned maintenance will be performed on the motor driven AFW Pumps No planned maintenance will be performed in the switchyard No planned maintenance will be performed on the Emergency Diesel Generators All Main Feedwater Pumps are available with no maintenance planned during this time period All Condensate Pumps are available with no maintenance planned during this time period Operating shifts will be briefed on the actions of abnormal procedure AP-22.1, Loss of 2-FW-P-2 Turbine Driven Aux. Feedwater Pump, specifically the ability to cross-tie Auxiliary Feedwater Pumps if required.
SIGNIFICANT HAZARDS CONSIDERATION The proposed Enforcement Discretion for the Action Statement of Technical Specification requirement 3.7.1.2.a for an inoperable AFW pump does not result in a significant hazards consideration as defined in 10 CFR 50.92. Specifically, the proposed Enforcement Discretion does not:
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Involve a significant increase in the probability or consequences of an accident previously evaluated. The core damage frequency incrementalincrease was determined to be approximately 9.0E-8/yr. This incrementalincrease is judged to be negligible. Allowing an additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> for the repair associated with the Steam Driven Auxiliary Feedwater Pump is acceptable, since the AFW system remains capable of performing its intended function. During the extended maintenance and test period, appropriate compensatory actions arc being implemented. Therefore, the consequences of accidents related to or dependent on AFW system operation will not be significantly affected.
Create the possibility of a new or different kind of accident from any previously evaluated. There are no new failure modes or mechanisms associated with plant operation for an extended period to perform maintenance on the Steam Driven Feedwater Pump.
Extended operation with an inoperable Steam Driven Feedwater Pump does not involve any modification in the operational limits or
tw 11 9a 16:18 rto
- p..ua physical design of the involved systems. There are no new accident precursors generated due to the extended maintenance period.
Involve a significant reduction in the margin of safety. Plant operation for an additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with the inoperable Steam Driven Feedwater Pump does not adversely affect the margin of safety. During the extended maintenance period the AFW system maintains the ability to perform the safety function.
Compensatory actions will remain in effect to assure that the safety margins are maintained.
ENVIRONMENTAL CONSEQUENCES This Enforcement Discretion will not change the types of any effluents that may be released offsite, nor create a significant increase in individual or cumulative i
occupational radiation exposure since the proposed action only extends an existing action statement interval by an additional 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
Furthermore, the proposed changes do not affect the ability of the AFW System to perform its intended safety function. Therefore, the consequences of accidents related to or dependent on AFW System are not adversely affected.
The Enforcement Discretion was reviewed and approved by the Station Nuclear Safety and Operating Committee.
Very truly yours, g, W. L. Stewart Senior Vice President - Nuclear cc:
i U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D. C. 20555 Mr. R. D. McWhorter NRC Senior Resident inspector North Anna Power Station Pr wee =
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