ML20214E022

Forwards Rev 2 to ATWS Mitigation Sys Specific Design for Byron/Braidwood Stations, Per 870209 Telcon W/Nrc. Rev 2 Includes Resolution of Issues Discussed on 870209 & Addressed Through Westinghouse Owners Group

ML20214E022
Person / Time
Site:	Byron, Braidwood, 05000000
Issue date:	05/11/1987
From:	Leblond P COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20214E025	List: ML20214E022 ML20214E058
References
NUDOCS 8705210599
Download: ML20214E022 (2)

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- One Fret Nabonel Plaza, CNcago. Illinois

..k ~ l Address Reply 10: Post Ofilm Box 767 CNeago,lanoiseoseo 0767 t

May 11, 1987 jj U.S. Nuclear Regulatory Comunission

. Attn: Document Control Desk

.ilashington, DC 20555

Subject:

' Byron Station Units 1 and 2 i Braidwood Station Units 1 and 2 ATWS Protection - 10 CFR 50.62 l

-NRC Docket Nos. 50-454/455 and 50-456/457 References (a): December 12, 1986 letter-from P.C. LeBlond to H.R. Denton (b): January 30, 1987 letter from P.C. LeBlond H.R. Denton Centlemen:

A teleconference was held on February 9,1987 with Comunonwealth

. Edison personnel and L.N. Olshan along with other members of the NRC staff.

' .The purpose of that teleconference was to discuss commonwealth Edison Company's proposed design for the ATWS Mitigation System for the Byron /Braidwood Stations. This design had been previously submitted in j references (a) and (b).

i This submittal is transmitting a copy of Revision 2 to "ATWS

~ Mitigation System Specific Design for Byron /Braidwood Stations". Revision 2 includes resolution of issues that were discussed on February 9, 1987 and issues that have-recently been addressed through the Westinghouse owners

! Group.

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! 0705210599 870511 PDR ADOCK 05000454 .

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Specifically, the design changes include;

.a) .AMS arming to be automatic rather than manual b). C-20 permissive de-energizing time delay to be 120 seconds rather than 60 seconds c) reduction in the C-20 setpoint from 70% nominal load to 40%

d) reduction in the feedwater flow setpoint frca 50% of nominal feed flow to 25%

If any further questions arise regarding this irisue, please direct them to this office.

Very truly yours, hk b P.C. LeBlond Nuclear Licensing Administrator cs cc: Byron Resident Inspector Braidwood Resident Inspector Regiona1' Administrator - RIII J.A. Stevens - NRR L.N. Olshan - NRR s.

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