ML17252B413

Letter Regarding Dresden Station Units 2 and 3 Torus-To-Drywell Vacuum Breaker Bushings

ML17252B413
Person / Time
Site:	Dresden
Issue date:	12/15/1976
From:	Stephenson B B Commonwealth Edison Co
To:	Keppler J G NRC/RGN-III
References
50-237/1974-27A, BBS Ltr. #76-883, LER 74-027-00, LER 74-027A-00
Download: ML17252B413 (1)

Text

,,.. ***.*.* ** . -'* CommonweM'I Edison Dresden Nucle-wer Station R.R. #1 Morris, Illinois

• so450 Telephone 815/942-2920

• • .. -l:--,., . . *"' ___________

LTR._/l-7_6-883 De_cembei;-.

19.79 Mr. James G. Keppler, Regional Director Directorate of Regulatory Operations

,£?'Region TII U. S. Nuclear Regulatory Commission 799 Road Gien Ellyn, Illinois 60137 .SUBJECT.:

Dresden Station Torus-to-Drywell Vacuum Breaker

REFERENCES:

1) Letter from B. B. Stephenson to J. F. O'Leary dated July 29, 1974 (Abnormal Occurrence report no. 50-237 /1974-27)

2) Drawing number:*

M-25. REPORT NUMBER: 50-237/1974-27A REPORT DATE: December 15, 1976 OCCURRENCE DATE: July 20, 1974 FACILITY:*

.Dresden Nuclear Power Station,.

Morris, Illinois

. . / . The referenced Abnormal Occurrence report s:tat;ed that a study was in . progress to evaluate the possible(::iuse of phosphorus-bronze in place of teflon as a bushing material in the breakers on Units 2 and 3. .-* The vacuum breaker performance has been monitored for approximately three years. During this period three binding pi;-oblems h.;ive been experienced; two

• with teflon bushings and one with phosphorus-bronze bushings.

Based on the results far there is no justification for of the teflon with bushings.

Additionally, based on the reduced frequency of failures, no other action is planned at this time. Power St?tion BBS: CES :jo cc: Director of Inspection

& Enforcement Director*

of Management Information

& Program Control File/NRC DEC 2 3 1976 13044 ....