ML20093L280
| ML20093L280 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 07/13/1984 |
| From: | Hukill H GENERAL PUBLIC UTILITIES CORP. |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 5211-84-2166, IEB-84-02, IEB-84-2, NUDOCS 8407310348 | |
| Download: ML20093L280 (2) | |
Text
y 1
GPU Nuclear Corporation Nuclear
- =,omg:48o Middletown, Pennsylvania 17057 0191 717 944 7621 TELEX 84-2386 Writer's Direct Dial Number:
5211-84-2166 July 13,1984 Dr. Thomas E. Murley Region I, Regional Administrator U. S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, PA.19406
Dear Dr. Murley:
Three Mile Island Nuclear Station, Unit I, (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 IE Bulletin 84-02 This letter is being submitted in response to IE Bulletin 84-02 entitled
" Failures of General Electric Type HFA Relays in Use in Class IE Safety Systems".
The actions stated in IE Bulletin 84-02 which pertain to General Electic HFA Relays do not apply to THI-1, since these relays are not used in any safety related applications at THI-1. However, the bulletin also asks that "the general concerns expressed" be reviewed for applicability.
The concern which was identified for the HFA Relays was an "end of life" condition for continuously energized AC coils.
The preventive maintenance program at TMI-1 includes the trending of failures such that when a failure rate reaches a predetermined threshold an engineering evaluation is requested. This practice aids in detecting the end of life conditions as well as other failure mechanisms.
Predicting end of life for coils is difficult because of many variables, such as voltage, ambient conditions and percent of time energized.
It appears that the type (normally open or normally closed) of contacts also affects the coil because the contact spring aids or opposes pickup depending on the type of contact.
8407310348 e40713 gDRADOCK 05000289 PDR GPU Nuclear Corporation is a subsidiary of the General Public Utilities Cor3 oration
.~
5211-84-2166 Dr. Thomas E. Murley End of life coil failure was listed as a probable cause for LER 83-024/99X-0, ESAS Actuation Relay Cofi Failure. These relays were Clark /GTE Sylvania Type PM 7305 AC Relays. The commitment from GPUN to replace all ESAS actuation relay coils was fulfilled in May 1984. Subsequent to replacement of the relay coils, TMI-1 experienced failures of additional coils.
The failure of the new coils indicates that the problem may not have been end-of-life failure.
The subsequent failures resulted in partial ESAS actuations on June 3, 1984 and June 30, 1984. The description of these failures was reported in LER 84-002-0.
Sincerely, H. D.
u ill, Director, TMI-1 HDH/MRK/mle Sworn and subscribed 4
to before, t is /8 day of C
, 1984.
0Ai d el ary Public JULIA L PARE. W W tisdi.e
.,o
,u n m b lAy Commission Emphes it.v. 3,1996 f
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.