ML20217G160

Supplements & Responds to 970910 Telcon Re Clarification to SE of LaSalle County Station Response to Station Blackout Rule

ML20217G160
Person / Time
Site:	LaSalle
Issue date:	10/03/1997
From:	Subalusky W COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
TAC-M68559, TAC-M68560, NUDOCS 9710090244
Download: ML20217G160 (3)

Text

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la l Hi% 3%Wht October 3,1997 l United States Nuclear Regulatory Commission l Attention: Document Control Desk l Washington, D.C. 20555

Subject:

Clarification tc the Safety Evaluation of the LaSalle l County Station Response to the Station Blackout Rule I

(TAC Nos. M68559 and M68560)

LaSalle County Station, Units 1 and 2 Facility Operating License NPF-11 and NPF 18 NRC Docket Nos. 50 373 and 50 374

References:

1. W.T. Subalusky letter to U.S. NRC dated May 28,1997

2. T. Kovach letter dated to B. Siegel dated March 6,1992 This letter supplements the Reference 1 letter and responds to a telecon discussion with the LaSalle NRC Project Manager on September 10,1997.

The referenced letter requested an SER clarification that addresses a proposed minimum 5% remaining battery margin for Station Blackout (SBO) and the adjustment of the aging factor,if necessary, as an acceptable method to maintain this margin. The referenced letter also stated that w I g appropriate procedures would be revised to require verification that the batteries have a minimum capacity consistent with the aging factor used in the SBO battery sizing calculations. Allowing adjustment of the aging factor would provide LaSalle additional flexibility in addressing SBO battery hI capacity issues without prior NRC approval.

Two questions were brought up during the September 10,1997 telecon; (1)

How will the requirement to replace the class 1E batteries at 84% be implemented? and (2) What plant documents will be changed, if any, to reflect the change to the aging factor for the class 1E batteries?

9710090244 DR 971003 p ADOCK 05000373 eua.

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4 The requirement to replace the 125V de Division 1 and 2 class 1E 1.

batteries and the 250V de class 1E batteries when the capacity reaches the value corresponding to the aging factor used in the SBO Battery Sizing Calculation will be implemented by revising the applicable procedure (s). Specifically, the revised procedure (s) will reflect a minimum battery capacity that corresponds to the aging factor used in the calculation and a reference to the calculation as a basis for the minimum capacity. The battery performance test procedure will include words similar to ' verify the battery capacity is at least (e.g.,84%) of the manufacturer's rating when subjected to a performance discharge test. If the battery capacity is determined to ,

be less than (e.g.,84%) of the manufacturer's rating, then the perfomiance test is unsatisfactory. The specific battery capacity value reflected in the procedure (s) will be based on the aging factor used in the SBO battery sizing calculation. The procedure (s) will also reference the appropriate licensing correspondence / documents.

Please note that a specific aging factor, as implied in the above question, was not identified in the referenced letter. The intent Is to maintain flexibility in addressing capacity issues while maintaining a minimum remaining margin of 5% by adjusting (e.g., reducing) if necessary, the aging factor at the expense of earlier battery replacement, t

2. In addition to revising the applicable procedure (s), as discussed in the response to the first question, the UFSAR will be revised to reflect (1) a minimum remaining margin of 5% regarding the SBO battery capacity, (2) that the aging factor may be adjusted (i.e., may be less than 1.25) to maintain the minimum 5% remaining margin and (3) that -

the appropriate procedure (s) will require verification that the batteries have a minimum capacity consistent with the aging factor used in the SBO battery sizing calculations. As In the current revision of the UFSAR, the design margin used in the SBO battery sizing will remain unchanged at 1.0.

Please recognize that LaSalle has identified the battery remaining margin for SBO as an issue requiring resolution prior to restarting either of the Units and as such, would appreciate your immediate attention to this matter.

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! . If there are any questions or comments concerning this letter, please refer them to Perry Barnes, Regulatory Assurance Supervisor, at (815) 357 6761, i i

extension 2383. j

. i Respectfully,  !

ft"  % l l F m i W.T Subalusky i Site Vice President i LaSalle County Station  !

cc: A. B. Beach, NRC Region lli Administrator .

M. P. Huber, NRC Senior Resident inspector LaSaho 1 D. M. Skay, Project Manager NRR LaSalle  :

F. Nlziolek, Office of Nuclear Facility Safety IDNS 1 i

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