ML20137K293

Provides Supplemental Response to Electrical Distribution Sys Functional Insp Repts.Status Rept on Degraded Voltage Setpoint Methodology,Provided

ML20137K293
Person / Time
Site:	LaSalle
Issue date:	03/28/1997
From:	Subalusky W COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9704070001
Download: ML20137K293 (3)

Text

-. . .- ~ . . - . . - - - - - . . ~ - . - . . . . , . . . . . . . . . - --. - ~. - ~~- -- -

(limmonwealth litison Company e 125.ille Generating Station

. 2 Nil North 21st Road Marmiles. 11. 613 4 l >>T

. Tel 819 35'6**6I i

N 4

6

, March 28,1997

United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555

Subject:

LaSalle County Station, Units 1 and 2

, Supplemental Response to Electrical Distribution 4 System Functional Inspection (EDSFI) Reports j 50-373/91019 and 50-374/91019; j

Deviation 373/91019-05D and 374/91019-05D 4

Status Report on Degraded Voltage Setpoint Methodology NRC Docket Nos. 50-373 and 50-374 i

References:

1. T. J. Kovach letter to U.S. NRC, dated

, January 16,1999, transmitting response to NRC i inspection Reports 50-373/91019 and i

50-374/91019 regarding the Electrical Distribution i System Functional Inspection (EDSFI) report. l l 2. T. J. Kovach letter to U.S. NRC, dated I

! April 30,1992, transmitting supplemental response to the subject unresolved item.

3. T. O. Martin (U.S. NRC) letter to L.O. DelGeorge, i

dated March 12,1993, transmitting Inspection l Report Nos. 50-373/93002 and 50-374/93002.

4. M. B. Depuydt (Comed) letter dated June 22,1993, to T. E. Murley (U.S. NRC) transmitting supplemental response to the subject 4

unresolved item.

I j

. Oo<gQ N i O,I b g h1 )>

9704070001 970328 3 ADOCK 0500 gDR a l} Ih$I dINl b . ..

s

5. G. G. Benes (Comed) letter dated January 27,1994, to T. E. Murley (U.S. NRC) transmitting supplemental response to the subject unresolved item.

6. R. E. Querio (Comed) letter dated February 27,1996, to U.S. NRC transmitting supplemental response to the subject unresolved item.

In reference 6, LaSalie County Station provided a description and status of the degraded voltage modifications that were required to resolve the subject EDSFl Deviation Item 373(374)/19019-05d. LaSalle County Station also provided a schedule to complete (1) the 120 VAC distribution circuit modifications on each unit prior to startup following the Unit 2 seventh refueling outage and (2) the degraded voltage setpoint change during the first refueling outage following approval of the Technical Specification amendment for revising the trip setpoint and allowable value for this parameter.

The purpose of this letter is to:

1. Provide a status of the 120 VAC distribution circuit modifications.

2. Clarify each unit's completion date for the degraded voltage setpoint change prior to startup following the eighth refueling outage of each unit.

120 VAC Distribution Circuit Modifications The modifications for the 120 VAC distribution circuits, listed in reference 6, were completed during the current Unit 2 seventh refueling outage. This action completes all plant equipment modifications required to ensure adequate voltage to safety equipment under degraded voltage conditions.

Dearaded Voltaae Setooint Chanae The one remaining open item for the degraded voltage issue is the setpoint change. A Technical Specification amendment is required for revising the degraded voltage setpoint and allowable value before this setpoint change can be implemented. The planned schedule provided in reference 6 was to complete the degraded voltage setpoint analysis and submit the required Technical Specification amendment by the end of the first quarter 1997. The Technical Specification Amendment was to be implemented during the refueling outage following approval of the Technical Specification Amendment, which is the eighth refueling outage of each unit.

I

' The engineering calculation for updating the degraded voltage analysis for Unit 2 has been completed. This calculation shows that the existing degraded voltage calibration setpoint (which is a compensatory setpoint as referred to in Reference 6) is conservative with respect to the final setpoint which will be prepared in the Technical Specification Amendment.

The engineering calculation for updating the degraded voltage analysis for Unit 1 will be completed prior to startup from the current unit outage (L1F35) to ensure that the existing compensatory degraded voltage calibration setpoint on Unit 1 is also conservative with respect to the final setpoint.

The Technical Specification Amendment for both units based on the degraded voltage setpoint analysis will be submitted no later than ninety days following startup of Unit 1 from its current outage. This will ensure that the amendment will be approved for implementation prior to the eighth refueling outage of each unit.

If there are any questions or comments conceming this letter, please refer them to me at (815) 357-6761, extension 3600.

Respectfully, M i

~ u p.

W. T. Subalusky Site Vice President LaSalle County Station cc: A. B. Beach, NRC Region lll Administrator M. P. Huber, NRC Senior Resident inspector - LaSalle D. M. Skay, Project Manager - NRR - LaSalle F. Niziolek, Office of Nuclear Facility Safety - lDNS

..y . . , - - - , - . , ,