Event Notification Report for December 29, 2000

                    U.S. Nuclear Regulatory Commission
                              Operations Center

                              Event Reports For
                           12/28/2000 - 12/29/2000

                              ** EVENT NUMBERS **

37637  

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|Power Reactor                                    |Event Number:   37637       |
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| FACILITY: COOPER                   REGION:  4  |NOTIFICATION DATE: 12/28/2000|
|    UNIT:  [1] [] []                 STATE:  NE |NOTIFICATION TIME: 12:21[EST]|
|   RXTYPE: [1] GE-4                             |EVENT DATE:        12/28/2000|
+------------------------------------------------+EVENT TIME:        07:41[CST]|
| NRC NOTIFIED BY:  STEVE WHEELER                |LAST UPDATE DATE:  12/28/2000|
|  HQ OPS OFFICER:  BOB STRANSKY                 +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          N/A                   |CHARLES MARSCHALL    R4      |
|10 CFR SECTION:                                 |                             |
|AESF 50.72(b)(2)(ii)     ESF ACTUATION          |                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR|   INIT RX MODE  |CURR PWR|  CURR RX MODE   |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|1     N          Y       100      Power Operation  |100      Power Operation  |
|                                                   |                          |
|                                                   |                          |
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                                   EVENT TEXT                                   
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| CONTROL BUILDING VENTILATION ISOLATION                                       |
|                                                                              |
| "At 0741 CST the Control Building Emergency Filtration System automatically  |
| initiated on a Control Building Intake Gas High Activity alarm. The cause of |
| the Gas High Activity alarm is under investigation."                         |
|                                                                              |
| The NRC resident inspector has been informed of this event by the licensee.  |
|                                                                              |
| * * * UPDATE ON 12/29/00, 0024 ET BY MYERS TAKEN BY MACKINNON * * *          |
|                                                                              |
| During the day, trouble shooting was performed to determine the source of    |
| the actuation at 0741 CST today. Surveillance Procedure 6.PRM.317, CONTROL   |
| ROOM AIR SAMPLING SYSTEM ELECTRONIC CALIBRATION, was performed, and all      |
| indications were within specification.  A source check of the gaseous        |
| channel was also performed per Instrument Operating Procedure 4.17, and the  |
| response of the monitor was normal.  Air sampling was conducted, and no      |
| indications of abnormal radiation were identified.  The Control Room         |
| Emergency Filtration System was returned to the standby lineup.              |
|                                                                              |
| At 1933, the Control Room Emergency Filtration System again initiated on a   |
| high gaseous activity signal.  All equipment functioned as required.  The    |
| Control Building Ventilation Radiation Monitor has been declared inoperable, |
| and the Control Room Emergency Filtration System remains in service, aligned |
| in the accident mode.                                                        |
|                                                                              |
| Note: The Control Building Ventilation Radiation Monitor consists of three   |
| channels, with two required to be operable.  The Iodine channel is also      |
| presently inoperable.  The actuation logic requires only one channel of the  |
| three to initiate Control Room Isolation and start the Emergency Booster     |
| (pressurization) fan.                                                        |
|                                                                              |
| Noble gas sample was taken at 2142 CST.  All readings were normal.   NRC     |
| R4DO (C. Marschall) notified.                                                |
|                                                                              |
| The NRC Resident Inspector will be notified of this event by the licensee.   |
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