United States Nuclear Regulatory Commission - Protecting People and the Environment

Morning Report for August 30, 2002



                       Headquarters Daily Report

                         AUGUST 30, 2002

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                    REPORT             NEGATIVE            NO INPUT
                    ATTACHED           INPUT RECEIVED      RECEIVED

HEADQUARTERS                           X
REGION I                               X
REGION II                              X
REGION III          X
REGION IV                              X





PRIORITY ATTENTION REQUIRED  MORNING REPORT - REGION III  AUGUST 30, 2002

Licensee/Facility:                     Notification:

Exelon Generation Company, Llc         MR Number: 3-02-0025
Braidwood 2                            Date: 08/29/02
Braceville,Illinois                    SRI via phone
Dockets: 50-457
PWR/W-4-LP

Subject: Unplanned Shutdown and Investigation of
         Rod Control Power Supply Alarms


Discussion:

On Tuesday August 27, 2002, at 9:30 a.m. the licensee received a
non-urgent rod failure followed by an urgent control rod failure alarm
and an MG set trouble alarm for all five control rod power supply
cabinets for Unit 2. At 11:38 a.m., control rod K-6 dropped. No control
rod testing or movement was occurring at the time. After limited trouble
shooting, the licensee commenced a controlled shutdown on August 28,
2002, at 5:30 p.m., took the main generator off-line at 9:54 p.m. and
opened the reactor trip breakers at 10:20 p.m.

Prior to the shutdown, gripper coil voltages indicated about 190 to 200
millivolts. The expected voltage was 270 millivolts. The manufacturer
(Westinghouse) stated that 190 millivolts is marginal for holding the
gripper coils; therefore, the licensee conducted the shutdown in order to
conduct a more extensive investigation. Currently, the licensee
identified missing power supply heat sink insulators in two of the five
power supply cabinets and continues to trouble shoot. The licensee has
the necessary parts on site to perform replacements if necessary.

Regional Action:

The resident inspectors monitored the shutdown and will continue to
follow the troubleshooting and subsequent activities.

Contact:  ANN MARIE STONE            (630)829-9729
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