ML20101J667

Provides Addl Info Discussed During 960325 Conference Call Re Modifying Ms Tunnel Automatic Isolations

ML20101J667
Person / Time
Site:	LaSalle
Issue date:	03/26/1996
From:	Querio R COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9604020087
Download: ML20101J667 (2)

Text

Commonwealth Edimn Comp.my

• .!2%alle Generating Station  !

. 2601 North 21st Riud l Marseilles. IL 613 s 1-9757

'lel H 15-357C61 l

l March 26,1996 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 l

Subject:

LaSalle County Nuclear Power Station Units 1 and 2 I Submittal of Additional Information discussed during the March 25,1996 Conference Call Regarding Modifying ,

the Main Steamline Tunnel Automatic Isolations j NRC Docket Nos. 50-373 and 50-374

References:

1. G. Benes letter to U. S. NRC, dated )

January 18,1996, LaSalle Submittal Regarding Main Steamline Tunnel Leak Detection isolations

2. G. Benes letter to U. S. NRC, dated March 1,1996, Comed Response to NRC Staff Request for AdditionalInformation ,

3. R. Querio letter to U. S. NRC, dated March 22,1996, Comed Submittal of Additional l Information

)

l Reference (a) provided LaSalle Station's proposal for revising the Technical Specification requirements for the Main Steamline Tunr ' Automatic Isolations. Reference (b) provided Comed's Response u .he NRC staff request for additional information. Reference (c) provided additional Comed information. The purpose of this letter is to provide additionalinformation  ;

that was discussed during the March 25,1996 conference call between NRR and Comed.

On page 1 of Attachment A to the Reference (c) submittalit was stated "The VR system provides ventilation to the entire reactor building and exhausts through the MST." This statement should be clarified to say "The VR system provides ventilation to the entire reactor building and 87% of the VR flow ,

exhausts through the MST."

9604020087 960326 PDR P

ADOCK 05000373 00 PDR i A Unicom Company

The remaining 13% of the VR exhaust flow is drawn from the Reactor Water l Clean Up (RWCU) heat exchanger rooms, RWCU valve rooms, Fuel Pooling l

Clean Up (FC) heat exchanger rooms, FC pump rooms, Clean Up phase separator rooms and associated valve rooms. This flow rejoins the MST exhaust flow in the Reactor Building Ventilation return air riser, before reaching the VR radiation monitors. Therefore all VR flow, including the increased value of 100 gpm steam leakage, passes the VR radiation monitors for the purpose of secondary containment isolation. Also note that all VR exhaust flow as well as the remainder of plant ventilation exhaust

! flows are monitored by a stack Wide Range Gas Monitor (WRGM). This stack WRGM assures that gaseous effluents are within the limits specified in l the ODCM, and in compliance with the release limits of 10 CFR 50, l Appendix 1.

l l The original Significant Hazards Consideration, that was included in the l Reference (a) submittal, remains valid.

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

Respectfully, l

WW' R E. Querio Site Vice President l LaSalle County Station Enclosure

! cc: H. J. Miller, NRC Region Ill Administrator D. M. Skay, Project Manager - NRR - LaSalle P. G. Brochman, NRC Senior Resident inspector - LaSalle Central file l

I

<