ML20195F619
| ML20195F619 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek  |
| Issue date: | 11/18/1988 |
| From: | Bailey J WOLF CREEK NUCLEAR OPERATING CORP. |
| To: | Martin R NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM), NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| REF-PT21-88, REF-PT21-88-147-000 ET-88-0177, ET-88-177, PT21-88-147, PT21-88-147-000, NUDOCS 8811220082 | |
| Download: ML20195F619 (2) | |
Text
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.n WQLF CREEK NUCLEAR OPERATING CORPORATION John A. Bedey Vu Proodont re and 7.cwas s**"
Novernber 18, 1988 ET 88-0177 U. S. Nuclear Regulatory Commission ATTN Document Control Desk Mail Station PI-137 Washington, D. C. 20555 R. D. Martin, Regional Administrator U. S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011
Subject:
Docket No. 50-482:
10 CVR 21 Not! fication Concerning General Electric Magne-Blast Circuit B r eak e rs Gentlemen This letter is being submitted pursuant to 10 CFR 21.21(b)(2) as a follow-up to a telephone call between K.
R.
- Petsraen, Wolf Crcek Nuclear Operating Corporation (WCNOC) and D. D. Chamberlein, NRC on November 16, 1988.
The corsponents which are the subject of this notification are er fety-related 4160V Ceneral Electric (C.E.)
Magne-Blast type AM-4.16-3 50 -211 circuit 4
b re ak e r s.
There tre a total of 32 safety related br eak e r s of this type installed at Wolf Creek Generating Station (WCCS).
In addition, WCCS utilizes this type of breaker in non-safety related applications.
WCNOC is currently conducting refueling outage operations at WCGS.
During routino inspections of the C.E.
Magne-Blas t break ers,
cracked welds were discovered on striker plates in 12 oC the 16 total breakers installed in one isafety relt.ted 4kV bus.
These breakers provide electrical power to safety-related loads during normal operation.
During certain accident conditions, these b re ak e r s raust open to Interrt t power, then reclose in a sequenced manner in order to fulfill their safety function.
The subject welds hold the latch roller link striker plate to the operating mechenine frame.
The latch roller link striker plate preventr latch roller link overtravel, which could preclude breaker reclosure once opened, ng11;;OOS2 ? 21 ! ! CD l
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An engineering evaluation of the condition indicated that the remaining welds were suf ient to provide reasonable assurance under current plant conditions (COLD SHUTDOWN / REFUELING) that the s t r ik e r plates would still perform their intended function until such time as the welds can be
- repaired, considering the limited number of cycles expected.
elds on all safety related b reak e rs will be repaired prior to entry into HOT SHUTDOWN (MODE 4).
Welds on non-safety tala*ed breakers will also be reworked af ter completion of the welds on the satety related breakers, but not necessarily prior to plant startuo.
General Electric Company has furnished information in Service Advice Letter
( S AL) 325.1, issued in 1978, which identifle this ptoblen.
Howeve",
SAL 325.1 indicates this problem existed in breakers shipped between le A and 1973.
The breakers installed at WCCS were shipped af te r this time period, In addition, the type breakers installed at WCCS, type AM-4.16-3 50-211, are not listed in the Service Advice Letter, but the letter does list ty pe AM-5.16-350-1C, 1H, 2C, or 2H.
A telephone call to General Electric revealed that the "5.16" is apparently, a typographical error and the designator should have been type AM-4.16-350-lC, 1 H, 2C, or 2H.
If you have any questions concerning this matter, please contact me or Mr. O. L. Mayna rd o f iay s ta f f.
Very truly yours, 0
John A. Bailey Vice President Engineering & Technical Services JAB /jad cct B. L. Bartlett (NRC)
D. D. Chamberlain (NRC)
D. V. Picket t (NRC) r I
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