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Home NRC Library Document Collections Events, Reports Associated with Part 21 Reports 1998

Part 21 Report - 1998-595

ACCESSION #: 9810260196

James S. Baumstark
Vice President
Nuclear Engineering

Consolidated Edison Company of New York, Inc.
Indian Point 2 Station
Broadway & Bleakley Avenue
Buchanan, New York 10511

Internet: baumstarkj@coned.com

Telephone: (914) 734-5354
Cellular: (914) 391-9005
Pager: (917) 457-9698
Fax: (914) 734-5718 		October 9, 1998
Re: Indian Point Unit No. 2
Docket No. 50-247

Document Control Desk
US Nuclear Regulatory Commission
Mail Station P1-137
Washington, DC 20555

SUBJECT: 10 CFR Part 21 Written Notification

On September 25, 1998, Con Edison submitted, by facsimile, the initial notification of a condition at Indian Point Unit No. 2, that we determined reportable under the requirements of 10 CFR Part 21. The reported condition involved failure to close a Westinghouse DB-75 breaker, used in the emergency diesel generator output circuit. We believe that the failure to close was due to a binding phenomena between the breaker's trip bar latch and the trigger in the operating mechanism and that Part 21 reporting applies to this case. The requirements of 10 CFR 21.21(d)(4) identify specific information to be included in this written notification. That information is provided in the attachment to this letter.

Should you have any questions regarding this matter, please contact Mr. Charles W. Jackson, Manager, Nuclear Safety and Licensing.

Very truly yours,

attachment

CC: Mr. Hubert J. Miller
Regional Administrator - Region I
US Nuclear Regulatory Commission
475 Allendale Road
King of Prussia, PA 19406
Mr. Jefferey F. Harold, Project Manager
Project Directorate I-1
Division of Reactor Projects I/II
US Nuclear Regulatory Commission
Mail Stop 14B-2
Washington, DC 20555
Senior Resident Inspector
US Nuclear Regulatory Commission
PO Box 38
Buchanan, NY 10511

ATTACHMENT

Indian Point Unit No. 2 Westinghouse DB-75 Breakers.

The following information is provided as required by 10 CFR 21.21(d)(4).

(i) Name and address of individual informing the Commission.
James S. Baumstark, Vice President - Nuclear Engineering.
Consolidated Edison Company of New York, Inc.
Indian Point Unit No. 2
Broadway and Bleakley Ave.
Buchanan, NY 10511
(ii) Identification of the basic component which contains a defect.
Component: Westinghouse 480V Breaker DB-75 Emergency diesel generator (EDG) output breakers EDG-2053-005 (serial no. 880.715-3) and EDG-2053-006 (serial no. 880.715-1)
(iii) Identification of the firm supplying the basic component which contains a defect.
Westinghouse Electric Company
Repair & Replacement Services
2000 Cheswick Avenue
Cheswick, PA 15024-1358
(iv) Nature of the defect and the safety hazard which could be created by such a defect.
On July 21, 1998, during the performance of the emergency diesel generator (EDG) load test the Westinghouse Model DB-75 output breaker EDG-2053-005 (serial no. 880.715-3), which connects the EDG to its 480VAC bus, would not close. A second attempt was made to close the breaker and again the breaker did not close. The breaker was removed and examined using high-speed photography. It was observed that the trip bar operation was hanging up. The exact cause of the trip bar malfunction was not initially identified so the mechanism was removed. During further investigation the trip bar latch and trigger were found to bind on occasion due to rough edges on the faces. Comparisons were made to other breaker mechanisms and these mechanisms could not be made to hang up in this area.
During the inspections made of the remaining DB-75 breakers, one additional breaker was found to exhibit the same binding problem. This was EDG breaker 2053-006 (serial no. 880.715-1). This breaker was of the same series as the original defective breaker, which may indicate a manufacturer's defect. Another breaker in the same series was examined but did not exhibit the same problem.
The safety hazard that could be experienced should the breaker fail to close would be that the diesel generator would not be put in service, which could result in a loss of a 480 V safety related power supply.
(v) The date on which the information of such defect was obtained.
The information that led to the determination of a potential part 21 issue was obtained August 12, 1998.
(vi) In the case of a basic component which contains a defect, the number and location of all such components in use at the facility subject to the regulations in this part.
Inspections of all DB-75 breakers were performed. One additional breaker was identified to have a similar latch and trigger binding problem.
(vii) The corrective action which has been taken.
The operating mechanism was replaced for the two breakers which had the latch and trigger binding problem. Both satisfactory passed a retest.
(viii) Any advice related to the defect that has been given to purchasers or licensees.
Westinghouse was provided with supporting technical information and a copy of the preliminary SAO 132b report.

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