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Event Notification Report for July 15, 2002

                         
                    U.S. Nuclear Regulatory Commission
                              Operations Center

                              Event Reports For
                           07/12/2002 - 07/15/2002

                              ** EVENT NUMBERS **

39056  39057  39058  
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|Power Reactor                                    |Event Number:   39056       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: SEQUOYAH                 REGION:  2  |NOTIFICATION DATE: 07/13/2002|
|    UNIT:  [] [2] []                 STATE:  TN |NOTIFICATION TIME: 01:45[EDT]|
|   RXTYPE: [1] W-4-LP,[2] W-4-LP                |EVENT DATE:        07/12/2002|
+------------------------------------------------+EVENT TIME:        22:23[EDT]|
| NRC NOTIFIED BY:  TOM RYAN                     |LAST UPDATE DATE:  07/13/2002|
|  HQ OPS OFFICER:  FANGIE JONES                 +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          NON EMERGENCY         |ANNE BOLAND          R2      |
|10 CFR SECTION:                                 |                             |
|ARPS 50.72(b)(2)(iv)(B)  RPS ACTUATION - CRITICA|                             |
|AESF 50.72(b)(3)(iv)(A)  VALID SPECIF SYS ACTUAT|                             |
|                                                |                             |
|                                                |                             |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR|   INIT RX MODE  |CURR PWR|  CURR RX MODE  
|
+-----+----------+-------+--------+-----------------+--------+-----------------+
|                                                   |                          |
|2     A/R        Y       100      Power Operation  |0        Hot Standby      |
|                                                   |                          |
+------------------------------------------------------------------------------+
                                   EVENT TEXT                                   
+------------------------------------------------------------------------------+
| REACTOR TRIP ON UNDERVOLTAGE ON REACTOR COOLANT PUMP BUSSES                 
|
|                                                                              |
| "At approximately 2223 on 07/12/2002, Sequoyah Unit 2 (SQN-2) received an    |
| Automatic Reactor Trip on Reactor Coolant Pump Busses undervoltage. The      |
| cause of the undervoltage was due to the loss of the Unit 2, 2B and 2D unit  |
| boards as a result of a loss of the 2B Start Bus. The 2B and 2D Unit Boards  |
| are the 6.9 kV electrical feeds to the 2-2 and 2-4 RCPS, respectively. Plant |
| response as a result of the loss of the Unit Boards was as expected,         |
| including the emergency start of all emergency diesel generators and the     |
| 2A-A Shutdown board being fed from Its emergency diesel generator.           |
|                                                                              |
| "Plant personnel were in the process of returning the 'B' Common Station     |
| Service Transformer (B-CSST) to service at the time of the event. The plant  |
| is currently being maintained in Mode 3 at NOT/NOP, 547 degrees F/ 2235 psig |
| respectively, by use of the plant's auxiliary feedwater system and steam     |
| dump system.                                                                 |
|                                                                              |
| "The cause of the trip of the 25 start bus is unknown at this time and       |
| investigation is on going. The Unit 2 Loop 4 atmospheric relief valve        |
| (2-PCV-1-30) which opened on the Reactor Trip and did not reclose. Manual    |
| operator action was taken to close the affected valve."                      |
|                                                                              |
| The licensee notified the NRC Resident Inspector.                            |
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+------------------------------------------------------------------------------+
|Power Reactor                                    |Event Number:   39057       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: HARRIS                   REGION:  2  |NOTIFICATION DATE: 07/13/2002|
|    UNIT:  [1] [] []                 STATE:  NC |NOTIFICATION TIME: 02:57[EDT]|
|   RXTYPE: [1] W-3-LP                           |EVENT DATE:        07/13/2002|
+------------------------------------------------+EVENT TIME:        01:10[EDT]|
| NRC NOTIFIED BY:  FRANK JACKSON                |LAST UPDATE DATE:  07/13/2002|
|  HQ OPS OFFICER:  FANGIE JONES                 +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          NON EMERGENCY         |ANNE BOLAND          R2      |
|10 CFR SECTION:                                 |                             |
|ARPS 50.72(b)(2)(iv)(B)  RPS ACTUATION - CRITICA|                             |
|AESF 50.72(b)(3)(iv)(A)  VALID SPECIF SYS ACTUAT|                             |
|                                                |                             |
|                                                |                             |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR|   INIT RX MODE  |CURR PWR|  CURR RX MODE  
|
+-----+----------+-------+--------+-----------------+--------+-----------------+
|1     M/R        Y       100      Power Operation  |0        Hot Standby      |
|                                                   |                          |
|                                                   |                          |
+------------------------------------------------------------------------------+
                                   EVENT TEXT                                   
+------------------------------------------------------------------------------+
| MANUAL REACTOR TRIP DUE TO DEH MALFUNCTION                                   |
|                                                                              |
| "Manual Rx trip due to DEH malfunction during initiation of downpower for    |
| scheduled valve testing. Automatic AFW actuation due to low S/G level        |
| following trip. 'C' S/G PORV remained open below lift setpoint. Valve shut   |
| manually from MCB."                                                          |
|                                                                              |
| The licensee further noted that only the motor driven AFW pump started on a  |
| single low level signal as expected.  The plant is stable in Mode 3, with    |
| normal feedwater and steam dumps to the condenser.  An investigation will be |
| completed prior to plant startup.                                            |
|                                                                              |
| The licensee notified the NRC Resident Inspector.                            |
+------------------------------------------------------------------------------+
.
+------------------------------------------------------------------------------+
|Power Reactor                                    |Event Number:   39058       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: WATTS BAR                REGION:  2  |NOTIFICATION DATE: 07/13/2002|
|    UNIT:  [1] [] []                 STATE:  TN |NOTIFICATION TIME: 18:42[EDT]|
|   RXTYPE: [1] W-4-LP,[2] W-4-LP                |EVENT DATE:        07/13/2002|
+------------------------------------------------+EVENT TIME:        16:22[EDT]|
| NRC NOTIFIED BY:  JOHN RODEN                   |LAST UPDATE DATE:  07/13/2002|
|  HQ OPS OFFICER:  LEIGH TROCINE                +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          NON EMERGENCY         |ANNE BOLAND          R2      |
|10 CFR SECTION:                                 |                             |
|ARPS 50.72(b)(2)(iv)(B)  RPS ACTUATION - CRITICA|                             |
|AESF 50.72(b)(3)(iv)(A)  VALID SPECIF SYS ACTUAT|                             |
|                                                |                             |
|                                                |                             |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR|   INIT RX MODE  |CURR PWR|  CURR RX MODE  
|
+-----+----------+-------+--------+-----------------+--------+-----------------+
|1     A/R        Y       100      Power Operation  |0        Hot Standby      |
|                                                   |                          |
|                                                   |                          |
+------------------------------------------------------------------------------+
                                   EVENT TEXT                                   
+------------------------------------------------------------------------------+
| AUTOMATIC TURBINE TRIP/REACTOR TRIP DUE TO ACTUATION OF A MAIN
TRANSFORMER   |
| DIFFERENTIAL ELECTRICAL RELAY                                                |
|                                                                              |
| The following text is a portion of a facsimile received from the licensee:   |
|                                                                              |
| "At 1622 on July 13, 2002, the Unit 1 reactor tripped due to an automatic    |
| signal.  All plant safety systems were in service at the time of the trip,   |
| and all systems responded as designed.  All control rods inserted as         |
| required, and the Auxiliary Feedwater (AFW) System initiated as expected."   |
|                                                                              |
| "The reactor trip resulted from a turbine trip signal that was generated as  |
| a result of a main transformer differential electrical relay actuation.  The |
| cause of the differential relay actuation is under investigation at this     |
| time."                                                                       |
|                                                                              |
| "The plant is currently stable in Mode 3 and will remain in this mode until  |
| completion of the investigation."                                            |
|                                                                              |
| The licensee stated that there were no related maintenance or surveillance   |
| activities ongoing at the time of the event but that there were heavy rains  |
| in the area earlier in the day.  The licensee also stated that normal        |
| charging and makeup, pressurizer heaters and sprays, and the reactor coolant |
| pumps are currently being utilized for primary system inventory, pressure    |
| and transport control.  Secondary system steam is being dumped to the        |
| condenser, and the main feedwater pumps are supplying water to the steam     |
| generators.  The auxiliary feedwater system has been secured, and            |
| containment parameters are normal.                                           |
|                                                                              |
| The licensee notified the NRC resident inspector.                            |
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