ML20052C353
| ML20052C353 | |
| Person / Time | |
|---|---|
| Site: | Washington Public Power Supply System |
| Issue date: | 04/02/1982 |
| From: | Root R WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | Faulkenberry R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, GO-1-82-0120, GO-1-82-120, NUDOCS 8205040692 | |
| Download: ML20052C353 (3) | |
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Docket Nos. 50-460/513
$0 55(e) Report Washington Public Power Supply System Pg 8 9b82 GO-1-82-0120 E8 Nuclear Regulatory Commission Q
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1 Attention:
Mr. R. H. Faulkenberry 6'
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Subject:
NUCLEAR PROJECTS 1 AND 4 E'
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DOCKET NOS. 50-460 AND 50-513 V,\\
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REPORTABLE CONDITION 10CFR50.55(e)
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GENERAL ELECTRIC CIRCUIT BREAKERS AKR-30 AND AKR-50
Reference:
Telecon ME Rodin, Supply System to
-PP Narbut dated March 2, 1982.
In the above reference the Supply System informed your office of a Poten-l tially Reportable Condition under the provisions of 10CFR50.55(e).
Attachment A to this letter, includes a statement of the identified condition and a brief description of our planned corrective action.
It has been concluded by the Project that the subject condition is report-able under the provision of 10CFR50.55(e) in that the circuit breakers are being utilized in Class IE safety related applications. It is antici-pated that the corrective action will be fully implemented and verified by the end of April 1983.
If circumstances change during the interim, we will promptly inform your office of the change (s).
If you have any questions or desire further information, please advise.
R. W. Root Acting Program Director RWR:MER:lm Attachment cc: CR Bryant, BPA/399 EW Edwards /860 V. Mani/897 A. Toth, NRC V. Stello, Director of Inspection, NRC FDCC/899 g5gg2 g h
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ATTACHMENT A WNP-1/4 DOCKET N0: 50-460 REPORTABLE CONDITION 10CFR50.55(e)
GENERAL ELECTRIC CIRCUIT BREAKERS TYPES AKR 30 AND AKR 50, SERVICE ADVICE N0 175-9.7 & 175-
9.7 BACKGROUND
The General Electric Co. in their letter dated February 10, 1982 informed the Supply System that potential problems exist in their electrically operated low voltage circuit breaker types AKR-30 and AKR-59.
This report provides the corrective action being taken to rectify the identified problems and appraises the NRC of the current status.
DESCRIPTION OF DEFICIENCY The General Electric Co. (GE) Service Advice No. 175-9.6 indicated that GE electrically operated low voltage circuit breaker types AKR-30 and AKR-50 manufactured before December 19, 1980 contain a bearing which may become deformed after the breaker is left in the charge position for several hours.
GE is not aware of any such failures but advised that the suspect bearing should be replaced with an improved bearing.
In addition, GE Service Advice No. 175-9.7 indicated that a flat head screw on the lower end of the closing spring assembly of AKR-30 and AKR-50 circuit breakers could "backout".
It was determined by GE that a thread locking compound, which should have been applied to the threaded portion of the flat head screw, had been intermittently omitted.
SAFETY IMPLICATIONS The potential bearing deformation in the breaker as identified in GE Service Advice No. 175-9.6 could result in failure of the circuit breaker to close upon command. This could result in safety related equipment not starting, when required, due to unavailability of power supply.
The possible omission of the thread locking compound required at the threaded portion of the flat head screw on the lower end of the closing assembly of the circuit breakers, as identified in GE Service Advise No. 175-9.7, could result in'the screw interferring with the charging of the circuit breaker closing spring.
This will prevent the circuit I
breaker from closing, which could prevent safety related equipment from starting for non-availability of the power supply.
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CORRECTIVE ACTION PLANNED The Architect-Engineer (AE) for WNP-1/4, United Engineers & Constructors, Inc. (UE&C) performed a review of all low voltage breakers being used on WNP-1/4 and have determined that a total of seventy-five (75) GE type AKR-30 and AKR-50 breakers have been used in various locations of the plant for Class lE applications.
These breakers were supplied by Powell Electric Manufacturing Co. These breakers will be shipped to the local GE facility for replacement of the potentially defective bearing and application of thread locking compound to the threaded portion of the flat head screw on the lower end of the breaker closing assembly.
The corrective action to bc taken by GE is expected to be completed by the end of March 1983.
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