PNO-III-87-047, on 870329,failure of Rocker Arm on Emergency Diesel Generator 2B Number 5 Right Cylinder Occurred. Concurrent Metallurgical Analyses Being Conducted to Determine Cause of Event

PNO-III-87-047:on 870329,failure of Rocker Arm on Emergency Diesel Generator 2B Number 5 Right Cylinder Occurred. Concurrent Metallurgical Analyses Being Conducted to Determine Cause of Event

ML20205T564
Person / Time
Site:	Braidwood
Issue date:	04/02/1987
From:	Kropp W, Little W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:
References
PNO-III-87-047, PNO-III-87-47, NUDOCS 8704070324
Download: ML20205T564 (1)

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PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-III-87-47 Data April 2, 1987 h Al A This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information is as initially received without MR verification or evaluation, and is basically all that is known by the Region III staff on this date.

Facility: Commonwealth Edison Company Licensee Emergency Classification:

Braidwood Unit 2 Notification of an Unusual Event Braceville, IL 60407 Alert Site Area Emergency l Docket No. 50-457 General Emergency X Not Applicable

Subject:

DIESEL GENERATOR ROCKER ARM FAILURE On March 29, 1987, during a 100-hour test run, a rocker arm failed on the 2B Emergency Diesel Gsnsrator's #5 right cylinder. The failure appears to be similar to rocker arm failures to the 2A Diesel Generator on February 4,1987 and February 12, 1987.

The licensee and Cooper-Bessemer, the diesel generator supplier, are presently conducting concurrent metallurgical analyses to determine the cause of the 28 diesel generator rocker arm failure. Cooper-Bessemer also is researching the history of the rocker arms and their manufacturer.

The licensee plans to submit a 10 CFR 50.55(e) report on the failure. (Unit 2 is currently undsr construction. Unit 1 is presently in Mode 3 awaiting authorization for initial criticality.

Unit l's two diesel generators have successfully completed their 100-hour full-load test runs.)

Region III (Chicago) is monitoring the licensee's course of action.

The State of Illinois will be notified.

R:gion III first learned of the rocker arm failure at 9 a.m. (CST), March 30, 1987. This information is current as of 10 a.m. (CST), April 2,1987.

CONTACT: W opp WL ie FTS 388-5578 FTS 388-5578 DISTRIBUTION:

H. St. ED0 NRR E/W Willste Mail: ADM:DMB Chairman Zech PA IE Comm. Roberts NMSS D0T:Trans only ELD OIA RES Comm. Asselstine AEOD NRC Ops Ctr ll*4 L Comm. Bernthal Conn. Carr SP lt:Q3 Regional Offices ACRS SECY INP0 \l*.35 NSAC ll*.40 CA RIII Resident Office

!PDR Licensee: ll*.45 (Corp. Office - Reactor Lic. Only) 8704070324 870402 PDR I&E Region III 9g PNO-III-87 % PDR Rev. November 1986

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