ML19250C537
| ML19250C537 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 11/02/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Arnold R METROPOLITAN EDISON CO. |
| References | |
| NUDOCS 7911280051 | |
| Download: ML19250C537 (11) | |
Text
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MI, 6
UNITED STATES f
^o NUCLEAR REGULATORY COMMISSION s31 PARK AVENUE K8NG OF PRUS$4 A. PENNSYLVANI A 1940s NOV 0 21979 Docket No. 50-320 Metropolitan Edison Company ATTN: Mr. R. C. Arnold, Sr.
Vice President 260 Cherry Hill Road Parsippany, New Jersey 07054 Gentlemen:
The enclosed IE Bulletin 79-25 is forwarded to you for infomation.
No written response is required at this time.
If you desire additional infomation regarding this matter, please contact this office.
Sincerely, A
f An -
Boyce H. Grier Director
Enclosures:
1.
IE Bulletin No. 79-25 w/ attachments 2.
List of IE Bulletins Issued in the Last Six Months CONTACT:
S. D. Ebneter (215-337-5283) cc w/encls:
J. G. Herbein, Vice President Nuclear Operations E. G. Wallace, Manager Licensing G. P. Miller, Manager Support Services and Logistics J. B. Logan, Superintendent Unit 2 G. A. Kunder, Unit 2 Superintendent - Technical Support J. J. Colitz, Manager Plant Engineering R. F. Wilson, Director TMI-2 Recovery, Acting I. R. Finfrock, Jr.
R. W. Conrad G. F. Trowbridge, Esquire J. B. Lieberman, Esquire Ms. Mary V. Southard, Chairperson, Citizens for a Safe Environment 1406 234 7911280 Ob
ENCLOSURE 1 UNITED STATES SSINS No.:
6820 NUCLEAR REGULATORY COMMISSION Accession No.:
OFFICE OF INSPECTION AND ENFORCEMENT 7908220139 WASHINGTON, D. C.
20555 IE Bulletin No. 79-25 Date:
November 2, 1979 Page 1 of 3 FAILURES OF WESTINGHOUSE BFD RELAYS IN SAFETY-RELATED SYSTEMS Description of Circumstances:
While conducting response time tests on Westinghouse BFD relays at the H. B.
Robinson facility, two relays were found to be stuck in the energized position with the coil de energized.
The twenty relays being tested were installed spares and provided no safety-related or operational function.
The subject relay is identified as a Westinghouse Electric Corporation type BFD, style 5069A95G03, coil style 1259C71G19.
Upon discovery of the two stuck relays in the test program, the licensee conducted response tests on similar relays installed in the Reactor Protection System.
During this additional testing a reactor trip relay was found to be stuck in the energized position.
Detailed investigation of the problem by the licensee's staff indicated that the armature was sticking to the armature stop post.
This condition is apparently created when heat generated by normally energized coils causes a softening and resultant flow of epoxy adhesive used to attach the magnetic antistick disc to the top of the armature stop post. When sufficient adhesive f.ows to the top of the armature stop, the armature becomes bonded to the stop post, resulting in the relay sticking in the energized position.
The epoxy adhesive had also discolored to a dark brown as opposed to clear in new relays.
After reviewing this problem, Westinghouse issued a service letter dated December 6, 1978. A copy of this letter is attached for your information and appropriate use.
Westinghouse recommended replacing affected relays with a relay identified as NBFD, style 5072A49, coil style 1271C50G01,125/130 Volt DC 10 percent.
During installation and testing of the new NBFD relays identified by Westinghouse, H. B. Robinson determined that some of the new style relays exhibited marginal or unsatisfactory armature overtravel.
An investigation of the problem by Westinghouse indicated that the insufficient overtravel was limited to eight and twelve pole models of the NBFD r ued a Technical Bulletin NS0-TB-79-05 to Licensees.
attached for your information and us method for identifying relays with i DUPLICATE DOCUMENT replacement of relays with insuffic1 Entire document previously entered into system under:
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