ML19340A967
| ML19340A967 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Quad Cities, Zion  |
| Issue date: | 08/17/1976 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Brian Lee COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 8009100905 | |
| Download: ML19340A967 (1) | |
Text
i UNITEo STATES i
NUCLEAR REGULATORY COMMISSION REGloN lit t
GLEN Ea LYN, ILLINOIS 60137 D
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Consmonwealth Edison Company Docket No. 50-10 ATTN:
Mr. Byron Lee, Jr.
Docket No. 50-237 Vice President Docket No. 50-249 P. O. Box 767 Docket No. 50-254 Chicago, T111nnis 60690 Docket No. 50-265 Dockat No. 50-295 Docket No. 50-304 Gentlemen:
The em 1nsed Circular, 76-02 is forwarded to you for information and action. This is the second issue of an expanded system for cons:runica-tion from the Office of Inspection and Enforcement to applicants and licensees, to supplement the issuance of IE Bulletins.
Bulletins have been, and will continue to be, limited to subjects con-
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sidered to be of appropriate significance to require prompt response.
Circulars will cover subjects of lesser significance, immediacy or for which a longer response time appears appropriate. Futura IE Circulars may be addressed to any class of NRC licensees, and :ay or may not require response.
Sincerely.
James G. Kappler Regional Director Rnt 1 nsure:
IE Cir m1mr 76-02 cc w/ encl:
Mr. B. B. Stephenson, Station Superintendent Mr. J. Bitel, Plant Superintendent Mr. N. Kalivdanakis, Station SuperineanA*nt
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August 17, 1976 IE Circular No. 76-02 RELAY FAILURES-WESTINGHOUSE BF (ac) AND BFD (de) RELAYS DESCRIPTION OF CIRCUMSTANCES:
During testing of Westinghouse BFD relays, the Point Beach nuclear power plant experienced malfunctions with two relays in the reactor trip system.
The malfunctions were caused by the pin that connects the plunger to the operating head rubbing against the contact olock.
Although the coils were fully energized the relay contacts remained in the deenergized position.
A similar malfunction occurred in one of a set of relays,ndergoing accelerated aging tests at the Westinghouse Beaver facility.
The malfunction relating to pin misalignment may be common to both BF (ac) and BFD (de) relays. Portions of a Westinghouse service letter containing information about these relays are attached to this circular.
Further instructions regarding this relay problem can be obtained from Westinghouse Nuclear Service Division, Pittsburgh, Pennsylvania 15230.
ACTION TO BE TAKEN BY LICENSEES AND PERMIT HOLDERS:
The following actions should be taken with respect to all Westinghouse BF (ac) and BFD (de) relays in safety related systeti:
1.
Describe the action taken or that you plan to take to verify that normally energized relays in safety related systems are in fact operable and that the relay contacts are in the energized position.
2.
Describe the action taken or that you plan to take to verify that normally deenergized relays in safety related systems operate properly when energize /. oud that the relay sontacts are in the energized position.
Reports for facilities with operating licenses should be submitted within 60 days af ter receipt of this circular, and reports for facilities with construction permits should be submitted within 90 days after receipt of this circular.
Your report should include the date when the above actions were or will be completed.
Reports shorid be submitted to the Director of the NRC Regional Office and a copy should be forwarded to the NRC Office of Inspection and Enforcement Division of Reactor Inspection Programs, Washington, D. C. 20555.
Approval of NRC requirements for reports concerning possible generic problems has been obtained under 44 U.S.C 3152 from the U. S. General Accounting Office.
(GAO Approval B-180255 (R0072), expires 7/31/77)
Attachment:
Extract from Westinghouse Service Letter:
BF (ac) and BFD ' (de) Relays
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' EXTRACT FROM WESTINGHOUSE SERVICE LETTER:
BF & BFD RELAYS During the testing of certain Westinghouse BFD relays at an operating nuclear power plant, two relays.in.the reactor trip system were found to have malfunctions. Although the coils were fully energized, the relay
-contacts remained in the deenergized position.
It was deturmined that, in both cases, the pin that connects the plunger to the operating head was rubbing against the contact block. This rubbing action resulted in friction that impeded the plunger movement when the relay coil was energized thereby preventing contact movement._ -The malfunctioning relays were insnediately replaced. When dissassembled it was found that the relays would operate normally when the pin'was centered in the plunger.
Coincidently, Westinghouse'-(Beaver) the relay manufacturer, experienced a similar malfunction in one of a set of similar relays which are currently undergoing accelerated aging tests.
Westinghouse (Beaver) and Westinghouse (NES) are currently investigating this situation in detail as it applies to both BF (ac) and BFD (de) models.
Con-sideration is being given to various means by which the pin could be held cap-tive, thereby precluding further pin misalignment, if,such a course of action becomes necessary.
RECOMMENDED ACTION Visually inspect normally energized relays to verify that such relays are in fact picked up.
Observe the performance of normally deenergized relays during normal periodic testing.
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