ML20054J150

From kanterella
Jump to navigation Jump to search
Updates & Clarifies Info Previously Submitted Re IE Bulletin 79-25, Failures of Westinghouse Bfd Relays in Safety- Related Sys. Annual Maint/Testing Program Set Up. Coils in Nbfd Relays Will Be Replaced
ML20054J150
Person / Time
Site: Calvert Cliffs  Constellation icon.png
Issue date: 06/16/1982
From: Lundvall A
BALTIMORE GAS & ELECTRIC CO.
To: Haynes R
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
References
REF-SSINS-6835 IEB-79-25, NUDOCS 8206280205
Download: ML20054J150 (2)


Text

_ . _ _ _ _ _ _ _ _ _

BALTI M O RE GAS AND ELECTRIC CHARLES CENTER. P. O. BOX 1475 BALTIMORE, MARYLAND 21203 ARTHun E. LUNDVALL. JR.

v cc p=see m ggg ggg Sumptv Mr. Ronald C. Haynes, Director U.S. Nuclear Regulatory Commission Office of Inspection & Enforcement Region 1 631 Park Avenue King of Prussia, PA 10406

SUBJECT:

Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 IE Information Notice 82-02

REFERENCES:

(a) NRC IE Bulletin 79-25, dated 11/2/79," Failures of Westinghouse BFD Relays in Safety-Related Systems" (b) BG&E Letter from A. E. Lundvall, Jr. to B. H. Grier, dated 12/27/79, Response to IE Bulletin 79-25 (c) BG&E Letter from R. F. Ash to B. H. Grier, dated 3/18/81, supplemental response Gentlemen:

In reviewing our current status regardmg the IE Information Notice 82-02 we felt it appropriate to provide an update and clarify some information previously submitted per references (b) and (c).

As reference (b) states, we have identified six safety related, normally energized BFD relays associated with the emergency diesel generator engine control circuitry of each diesel. Four of these relays perform an undervoltage alarm function and the remaining two actuate solenoid valves when they drop out. These six relays on each diesel engine, 18 in all, have been replaced with NBFD type relays, and prior to operation, the new relays were checked for sufficient " contact overtravel" as recommend by Westinghouse in Attachment 2 to the subject Bulletin. We have found no other safety related applications of BFD relays where they are in a normally energized state.

We have set up a maintenance / testing program on an annual basis with appropriate documentation per our Preventive Maintenance (PM) program. The steps described in the PM for the diesel generator control relays are as follows:

(1) Clean relays and enclosures with vacuum cleaner.

(2) Check relay contacts for proper operation and free movement.

(3) Check connections and fuses for tightness.

8206280205 820616 DR ADOCK 05000 g

Mr. Ronald C. Haynes June 16,1982 Page 2 (4) Relays indicated by an asterisk (relays in the normally energized state) will be operated several times electrically and continuity of their "used" contacts checked.

We feel this annual PM frequency is justified based on the low failure rate of the described BFD type relays in use at Calvert Cliffs. Also, we have removed all BFD relays from spare stock and will be replacing any failed BFD relays with the new NBFD type. Each defective relay would be documented on a Maintenance Request and that Maintenance Request would be retained in our plant history file.

Our Electrical Maintenance Group intends to replace the coils in all NBFD relays based on information provided in IE Information Notice 82-02. The replacement coil will be the type as specified on page 3 of Attachment I to IE Information Notice 82-02. All the NBFD relays in spare stock as well as those installed in the plant will have new coils installed.

We would be glad to discuss this matter with you, should you have any questions.

Very truly yours,

/

j /

( - (; qcwd'*A '

Vice Presid t - Supply AEL/ LOW /gla cc: 3. A. Biddison, Esquire G. F. Trowbridge, Esquire D. H. Jaffe, NRC R. E. Architzel, NRC

3. C. Ventura, Bechtel 1