COLUMBIA-2 - REACTOR TRIP AFTER TURBINE TRIP (CAUSE UNKNOWN)

COLUMBIA GENERATING STATION UNIT 2 - NOTIFICATION DATE: 06/30/2003

VALID REACTOR PROTECTION SYSTEM ACTUATION

The following information was obtained from the licensee via facsimile:

"This event notification is being made to report the valid actuation of the reactor protection system when the reactor was critical, and subsequent reactor scram. On June 30, 2003, [at 0918 PDT], the plant was in Mode 1 at 79% power, when a turbine trip occurred, followed by a reactor scram. The cause of the turbine trip is unknown at this time. All plant systems functioned properly in response to the scram. Operators are proceeding to bring the plant to Mode 4, Cold Shutdown, while investigation into the cause of the transient is completed."

During the scram, all rods inserted into the core. There were no lifts of power-operated or manual relief valves during the transient. The electrical grid is stable and powering all safety equipment. There were no other specified system actuations. Decay heat is being removed via the bypass valves to the main condenser.

The licensee has informed the NRC Resident Inspector.

+------------------------------------------------------------------------------+
|Power Reactor                                    |Event Number:   39965       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: COLUMBIA GENERATING STATIREGION:  4  |NOTIFICATION DATE: 06/30/2003|
|    UNIT:  [2] [] []                 STATE:  WA |NOTIFICATION TIME: 14:39[EDT]|
|   RXTYPE: [2] GE-5                             |EVENT DATE:        06/30/2003|
+------------------------------------------------+EVENT TIME:        09:18[PDT]|
| NRC NOTIFIED BY:  SCOTT BURTON                 |LAST UPDATE DATE:  06/30/2003|
|  HQ OPS OFFICER:  HOWIE CROUCH                 +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          NON EMERGENCY         |CHARLES MARSCHALL    R4      |
|10 CFR SECTION:                                 |                             |
|ARPS 50.72(b)(2)(iv)(B)  RPS ACTUATION - CRITICA|                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR|   INIT RX MODE  |CURR PWR|  CURR RX MODE   |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|2     A/R        Y       79       Power Operation  |0        Hot Shutdown     |
|                                                   |                          |
+------------------------------------------------------------------------------+