Event Notification Report for July 5, 2000

                    U.S. Nuclear Regulatory Commission
                              Operations Center

                              Event Reports For
                           07/03/2000 - 07/05/2000

                              ** EVENT NUMBERS **

37140  37141  

+------------------------------------------------------------------------------+
|Power Reactor                                    |Event Number:   37140       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: FITZPATRICK              REGION:  1  |NOTIFICATION DATE: 07/03/2000|
|    UNIT:  [1] [] []                 STATE:  NY |NOTIFICATION TIME: 11:10[EDT]|
|   RXTYPE: [1] GE-4                             |EVENT DATE:        07/03/2000|
+------------------------------------------------+EVENT TIME:        10:20[EDT]|
| NRC NOTIFIED BY:  BERNARD HORNING              |LAST UPDATE DATE:  07/03/2000|
|  HQ OPS OFFICER:  FANGIE JONES                 +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          N/A                   |STEVEN DENNIS        R1      |
|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  |
|                                                   |                          |
|                                                   |                          |
+------------------------------------------------------------------------------+
                                   EVENT TEXT                                   
+------------------------------------------------------------------------------+
| LOSS OF THE 'A' REACTOR PROTECTION SYSTEM BUS CAUSING MULTIPLE AUTOMATIC     |
| ACTIONS                                                                      |
|                                                                              |
| The unit experienced a loss of 'A' reactor protection system (RPS) bus.  RPS |
| motor generator output breakers opened and deenergized the bus, this caused  |
| the 'A' standby gas treatment to automatically start.  Also the 'A'          |
| hydrogen/oxygen monitor isolation valves closed, reactor building            |
| ventilation isolated, and the reactor water cleanup system tripped due to    |
| isolation valve closure.                                                     |
|                                                                              |
| This trip appears to be "identical" to a trip reported on 6/26/00, event     |
| #37119.                                                                      |
|                                                                              |
| The licensee has energized the 'A' RPS bus and returned all systems to       |
| normal operation with the exception of reactor water cleanup, which is being |
| restored.                                                                    |
|                                                                              |
| The licensee has notified the NRC Resident Inspector.                        |
+------------------------------------------------------------------------------+

+------------------------------------------------------------------------------+
|Power Reactor                                    |Event Number:   37141       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: SUSQUEHANNA              REGION:  1  |NOTIFICATION DATE: 07/04/2000|
|    UNIT:  [] [2] []                 STATE:  PA |NOTIFICATION TIME: 14:13[EDT]|
|   RXTYPE: [1] GE-4,[2] GE-4                    |EVENT DATE:        07/04/2000|
+------------------------------------------------+EVENT TIME:        11:54[EDT]|
| NRC NOTIFIED BY:  FITCH                        |LAST UPDATE DATE:  07/04/2000|
|  HQ OPS OFFICER:  CHAUNCEY GOULD               +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          N/A                   |STEVEN DENNIS        R1      |
|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   |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|                                                   |                          |
|2     N          Y       100      Power Operation  |100      Power Operation  |
|                                                   |                          |
+------------------------------------------------------------------------------+
                                   EVENT TEXT                                   
+------------------------------------------------------------------------------+
| THE PLANT HAD ESF ACTUATIONS DUE TO LOSS OF THE "B" RPS BUS.                 |
|                                                                              |
| "While operating at 100% power, Susquehanna Unit 2, experienced ESF          |
| actuations for containment isolations as a result of an unexpected loss of   |
| "B" RPS Bus caused by a trip of the RPS MG Set Output Breaker.  All          |
| containment isolations associated with a loss of "B" RPS Bus actuated and    |
| went to completion. "B" RPS power was swapped to the alternate power supply  |
| and affected systems restored to normal configuration."                      |
|                                                                              |
| The actuations received were cooling water to recirc pump isolation, RWCU    |
| isolation, containment sampling isolation, reactor building secondary        |
| containment isolations and coolant sampling isolations.  They also had       |
| standby gas treatment initiation.  The cause of the trip of the MG set is    |
| being investigated.                                                          |
|                                                                              |
| The NRC Resident Inspector was notified.                                     |
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