ML20148E024

Forwards Application for Amend to License NPF-3,revising Tech Specs to Allow one-time Extension of 30 Days to 18-month Surveillance Interval for Operability Testing of 13.8-kV Bus Transfer.Fee Paid

ML20148E024
Person / Time
Site:	Davis Besse
Issue date:	01/20/1988
From:	Shelton D TOLEDO EDISON CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20148E029	List: ML20148E024 ML20148E034 ML20148E055
References
1469, TAC-66967, NUDOCS 8801250545
Download: ML20148E024 (2)

Text

.

TOLEDO hEDISON DONALO C. SHELTON

u. m aw e

(.ii9l P49 7399 Docket No. 50-346 License No. NPF-3 Serial No. 1469 January 20, 1988 United States Nuclear Regulatory Commission Document Control Desk Washington, D. C. 20535

Subject:

License Amendment Application for One-Time Extension of the 18 Month 13.8 KV Bus Transfer Surveillance Interval (TAC No. 66967)

Gentlemen:

The enciesed application requests that the Davis-Besse Nuclear Power Station, Unit No. 1 Operating License, Appendix A, Technical Specifications be revised to reflect the change attached. The proposed change involves Section 3/4.8.1, Electrical Power Systems, A.C. Sources.

Specific.stion 4.8.1.1.lb. In addition, Specification 4.8.1.2 references Specification 4.8.1.1.lb requirements for Modes 5 and 6 operation.

The proposed change would revise the Technical Specifications to allow a one-time extension of thirty days to the 18 month surveillance interval for operability testing of the 13.8 KV bus transfer. This extension is necessary to avoid an unscheduled shutdown of the plant to perform this testing. The lact operability test, for which the interval extension is ,

requested, was performed prior to the eight month extension of the 1986 l outage (extended due to the unscheduled Reactor Coolant Pump (RCP) shaft replacement). This caused the next test to be due by March 1, 1988. As a result of the extension of the 1986 outage, the cotamencement of fifth refueling outage was rescheduled. Howevet, at that time the test due date of March 1, 1988 could be met. A decision to delay the start of the fifth refueling outage # rom February 15, 1988 to March 11, 1988 was made on January 5, 1988. This delay created the need for a one-time extension to l the surveillance interval. Approval of this proposed extension was 3 i received from the Station Review Board on January 12, 1988 and at a l special meeting of the Company Nuclear Review Board on January 14, 1988. i Since the last surveillance test, the operability of the 13.8 KV breakers 9 manual transfer capability has been demonstrated several times during routine electric system operations. Additionally, the ability to perform

[4 an automatic fast transfer from the normal power source (auxiliary I i

transfermer) to the selected of fsite sources (startup transformers) has $6 ,

8801250345 880120 ' '

'd PDR ADOCK 05000346

P PDR h THE TOLEDO EDISON COMPANY tulSON PLAZA 300 MADISON AVENUE TOLEDO, OHt0 43552

Docket No. 50-346 License No. NPF-3 Serial No. 1469 Page 2 been demonstrated several times as a result of plant trips. Although one of the breakers failed during the September 6, 1987, plant trip, follow-up post maintenance testing demo 1strated its operability. During the unit trip on December 7, 1987, the 13.8 KV busses automatically transferred to the correct offsite power supplies.

A NRC Augmented Inspection Team (AIT) which was onsite September 8 - 11, 1987, reviewed the failure of the breaker during the September 6, 1987 plant trip. As stated in their report (No. 50-346/87025, dated October 1, 1987): "The teem determined that the failure of the non-safety Bus A to auto transfer was of minimal safety significance because the safety Bus C1 was re-energized by the diesel generator as designed. The team concluded that the licensee had taken adequate corrective actions to ensure that the bus transfer circuitry will function as designed."

The AIT did, however, recommend that Toledo Edison re-evaluate its  !

interpretation of Technical Specification Surveillance Requirement 4.8.1.1.lb to include testing of the bus auto-transfer of the 13.8 KV busses from their normal source (auxiliary transformer) to their reserve sources (the startup transfomers). Toledo Edison is evaluating this recommendation and will incorporate any appropriate changes to the test procedure prior to the next performance of Surveillance Requirement 4.8.1.1.lb testing. This auto-transfer of the 13.8 KV busses has been demonstrated several times due to plant trips and the post-maintenance testing following the September 6, 1987 failure, thereby providing confidence in the system's capability to properly function.

Toledo Edison requests an expeditious NRC staff review and that this amendment be issued prior to March 1, 1988 to avoid shutdown of the Davis-Besse Nuclear Power Station.

Enclosed is a check for $150 as required by 10CFR170.12(c) for a License 1 Amendment Application.

Ve y tru 'ours, 1

JSL:lkg

&(

Enclosures i cc: DB-1 NRC Resident Inspector J

A. B. Davis, Regional Administrator (2 copies) )

A. W. DeAgazio NRC/NRR Davis-Besse Project Manager 1 State of Ohio l l

1 l

>