ML20212E287
| ML20212E287 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 06/04/1986 |
| From: | Carey J DUQUESNE LIGHT CO. |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 2NRC-6-058, 2NRC-6-58, 86-06, 86-6, NUDOCS 8608120649 | |
| Download: ML20212E287 (2) | |
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8eaver valley No. 2 Unit Project Organtration 2NRC-6-058 SEGBuilding (412) 643 5200 h pp [t,PA 15077 June 4, l'9N United States Nuclear Regulatory Commission Region I 631 P. ark Avenue King of Prussia, PA 19406 ATTENTION:
Dr. Thomas E. Murley Administrator
SUBJECT:
Beaver Valley Power Station - Unit No. 2 Docket No. 50-412 480V ITE Circuit Breakers Potentially Significant Deficiency Report 86-06 Gentlemen:
This Potentially Reportable Significant Deficiency Report relating to the failure of an ITE molded case circuit breaker is being submitted pursuant to the requirements of 10CFR 50.55(e).
This is an interim report.
DUQUESNE LIGHT COMPANY i
By e
J. 4. Carey
/V Vice President RWF/kam Attachment NRC/DEF/RPT/8606 1
cc:
Mr. P. Tam, Project Manager (w/a)
Mr. J. M. Taylor, Director (3) (w/a)
Mr. L. Prividy NRC Resident Inspector (w/a)
INP0 Records Center (w/a)
NRC Document Control Desk (w/a) 8608120649 860604
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PDR Tg: 21
F ATTACHMENT C
BEAVER VALLEY POWER STATION - UNIT 2 DUQUESNE LIGHT COMPANY REPORT ON P0TENTIAL SIGNIFICANT DEFICIENCY OF 480 V ITE/TELEMECANIQUE M0LDED CASE CIRCUIT BREAKERS 1.
Summary A failure of an ITE/Telemecanique molded case circuit breaker for a motor control center (MCC) to reset after trip was reported by DLC Maintenance Department.
2.
Immediate Action Taken Nonconformance and Disposition Report (N&D) 12325 was written on March 20, 1986 addressing this problem.
On April 1, 1986, Tele-mecanique field service engineer visited the site ta discuss possible solutions and extent of the deficiency.
3.
Description of the Deficiency The breaker reset mechanisum which is held by a slotted clip (latch cam) had moved laterally and come free, no longer providing tension to the reset mechanism.
This allors the breaker operating arm to move freely and not reset the breaker.
Further research and discus-sions with vendor revealed that this slotted latch cam was only manu-f actured during the period of October 6,1982 through April 1,1983.
After April 1,1983, the vendor changed the slotted clip design to a rectangular piece of metal with a hole in the center, thus eliminating movement and maintaining tension.
(This was the original design before October 6, 1983.)
4.
Analysis of Safety Implications The potentially deficient breakers are installed throughout the plant on the 480 V motor control centers in both Category 1E and non-Category 1E service.
Analysis of safety implications will be reported in a follow-up response.
5.
Corrective Action to Remedy Deficiency 1
N&D 12325 was dispositioned on April 15, 1986 requiring DLC Startup Group to inspect all 1650 480 V ITE/Telemecanique molded case circuit breakers and replace all latch cams having the slotted design with i
the originally designed part (rectangular with a hole in the center).
This replacement will be accomplished through the prevent-ative maintenance program using vendor supplied parts and instruct-r ions.
6.
Additional Reports l
This is a interim report.
An additional report will be submitted when the safety evaluation is completed.
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