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Event Notification Report for April 16, 1999

                    U.S. Nuclear Regulatory Commission
                              Operations Center

                              Event Reports For
                           04/15/1999 - 04/16/1999

                              ** EVENT NUMBERS **

35533  35592  35595  35596  

!!!!!!!!! THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED  !!!!!!!
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|Power Reactor                                    |Event Number:   35533       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: OCONEE                   REGION:  2  |NOTIFICATION DATE: 03/30/1999|
|    UNIT:  [1] [2] [3]               STATE:  SC |NOTIFICATION TIME: 20:50[EST]|
|   RXTYPE: [1] B&W-L-LP,[2] B&W-L-LP,[3] B&W-L-L|EVENT DATE:        03/30/1999|
+------------------------------------------------+EVENT TIME:        20:15[EST]|
| NRC NOTIFIED BY:  ED BURCHFIELD                |LAST UPDATE DATE:  04/15/1999|
|  HQ OPS OFFICER:  JOHN MacKINNON               +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          N/A                   |CHARLES OGLE         R2      |
|10 CFR SECTION:                                 |                             |
|AOUT 50.72(b)(1)(ii)(B)  OUTSIDE DESIGN BASIS   |                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR|   INIT RX MODE  |CURR PWR|  CURR RX MODE   |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|1     N          Y       100      Power Operation  |100      Power Operation  |
|2     N          Y       100      Power Operation  |100      Power Operation  |
|3     N          Y       100      Power Operation  |100      Power Operation  |
+------------------------------------------------------------------------------+
                                   EVENT TEXT                                   
+------------------------------------------------------------------------------+
| EMERGENCY OPERATING PROCEDURES (EOPs) AND ABNORMAL PROCEDURES (AP) DO NOT    |
| PROVIDE SPECIFIC GUIDANCE REGARDING  NECESSARY OPERATOR ACTIONS SHOULD LOW   |
| PRESSURE INJECTION (LPI) HEADER FLOW INDICATION BE LOST.  INTERIM GUIDANCE   |
| HAS BEEN PROVIDED TO ON-SHIFT OPERATORS TO ADDRESS THIS PROBLEM.             |
|                                                                              |
| During table top review and validation of EOPs, it was discovered that plant |
| procedures did not provide that necessary guidance to ensure adequate        |
| operator action will occur during a certain scenario.  A review of the EOPs  |
| has identified a scenario that is not adequately addressed in the procedure  |
| and therefore could place the Oconee Units outside their design basis.       |
| Specifically, the EOP requires throttling LPI header flow during a Large     |
| Break Loss of Coolant Accident (LOCA) to protect against potential pump      |
| runout.  If flow cannot be maintained, the EOP directs the operator to       |
| Abnormal Procedures (AP) AP/1/A/1700/007, "Loss of LPI System."  The EOP     |
| (EOP Section 505) and AP do not provide specific guidance regarding the      |
| necessary operator actions should LPI header flow indication be lost.  This  |
| could occur on a subsequent loss of a specific power supply.  Failure to     |
| take appropriate actions during a LOCA with this specific single failure     |
| could result in operators opening the LPI pump header cross connect valves   |
| (LP-9 and LP-10) per existing procedures, resulting in the potential loss of |
| both LPI pumps due to runout.  Interim guidance to close the valve of the    |
| affected Train (Train "A" is  LP-17 and Train "B" is LP-18)  so runout will  |
| not occur has been provided to the operators to address this potential       |
| deficiency, and the EOP is currently being revised.                          |
|                                                                              |
| The NRC Resident Inspector was notified of this event by the licensee.       |
|                                                                              |
| * * * UPDATE at 1120 on 04/15/99 from Reene Gambrell to Jolliffe * * *       |
|                                                                              |
| After further investigation of this event, Duke Power Company has determined |
| that there is no  credible single failure that would result in the loss of   |
| the safety and non-safety flow instrumentation on an LPI header.  Therefore, |
| adequate instrumentation was available for the operators to successfully     |
| mitigate a Core Flood Line Break accident, and this event is not reportable  |
| under 10CFR50.72.  Thus, the licensee desires to retract this event.         |
|                                                                              |
| The licensee notified the NRC Resident Inspector.  The Operations Officer    |
| notified the R2DO Pierce Skinner.                                            |
+------------------------------------------------------------------------------+

+------------------------------------------------------------------------------+
|Power Reactor                                    |Event Number:   35592       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: BRAIDWOOD                REGION:  3  |NOTIFICATION DATE: 04/14/1999|
|    UNIT:  [] [2] []                 STATE:  IL |NOTIFICATION TIME: 06:50[EDT]|
|   RXTYPE: [1] W-4-LP,[2] W-4-LP                |EVENT DATE:        04/14/1999|
+------------------------------------------------+EVENT TIME:        04:33[CDT]|
| NRC NOTIFIED BY:  PAT HABEL                    |LAST UPDATE DATE:  04/15/1999|
|  HQ OPS OFFICER:  DICK JOLLIFFE                +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          N/A                   |JOHN JACOBSON        R3      |
|10 CFR SECTION:                                 |                             |
|ARPS 50.72(b)(2)(ii)     RPS ACTUATION          |                             |
|AESF 50.72(b)(2)(ii)     ESF ACTUATION          |                             |
|                                                |                             |
|                                                |                             |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR|   INIT RX MODE  |CURR PWR|  CURR RX MODE   |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|                                                   |                          |
|2     A/R        Y       85       Power Operation  |0        Hot Standby      |
|                                                   |                          |
+------------------------------------------------------------------------------+
                                   EVENT TEXT                                   
+------------------------------------------------------------------------------+
| - AUTO Rx TRIP FROM 85% POWER DUE TO MAIN GENERATOR FAULT FOR UNKNOWN        |
| REASONS -                                                                    |
|                                                                              |
| AT 0433 CDT ON 04/14/99, UNIT 2 AUTOMATICALLY TRIPPED FROM 85% POWER DUE TO  |
| A MAIN GENERATOR TRIP CAUSED BY A MAIN GENERATOR FAULT FOR UNKNOWN REASONS.  |
| ALL CONTROL RODS INSERTED COMPLETELY.  BOTH TRAINS OF THE AUXILIARY          |
| FEEDWATER SYSTEM ACTUATED TO RESTORE STEAM GENERATOR WATER LEVELS TO NORMAL. |
| NO SAFETY OR RELIEF VALVES LIFTED.  STEAM IS BEING DUMPED TO THE MAIN        |
| CONDENSER.  ALL SYSTEMS FUNCTIONED AS DESIGNED.                              |
|                                                                              |
| UNIT 2 IS STABLE IN MODE 3 (HOT STANDBY).  THE LICENSEE IS INVESTIGATING THE |
| CAUSE OF THE MAIN GENERATOR FAULT.                                           |
|                                                                              |
| THE LICENSEE INFORMED THE NRC RESIDENT INSPECTOR.                            |
|                                                                              |
| * * * UPDATE AT 0408 ON 04/15/99 BY JOLLIFFE * * *                           |
|                                                                              |
| THE AUTOMATIC REACTOR TRIP WAS CAUSED BY A PROBLEM WITH A MAIN GENERATOR GIX |
| GROUND FAULT RELAY.  THE LICENSEE HAS BYPASSED THE RELAY AND RESTARTED UNIT  |
| 2.  THE LICENSEE IS CONTINUING TO INVESTIGATE THE ROOT CAUSE OF THE REACTOR  |
| TRIP.                                                                        |
+------------------------------------------------------------------------------+

+------------------------------------------------------------------------------+
|Power Reactor                                    |Event Number:   35595       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: BRAIDWOOD                REGION:  3  |NOTIFICATION DATE: 04/15/1999|
|    UNIT:  [] [2] []                 STATE:  IL |NOTIFICATION TIME: 14:47[EDT]|
|   RXTYPE: [1] W-4-LP,[2] W-4-LP                |EVENT DATE:        04/15/1999|
+------------------------------------------------+EVENT TIME:        13:01[CDT]|
| NRC NOTIFIED BY:  DAN ACKERMAN                 |LAST UPDATE DATE:  04/15/1999|
|  HQ OPS OFFICER:  LEIGH TROCINE                +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          N/A                   |JOHN JACOBSON        R3      |
|10 CFR SECTION:                                 |                             |
|ASHU 50.72(b)(1)(i)(A)   PLANT S/D REQD BY TS   |                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR|   INIT RX MODE  |CURR PWR|  CURR RX MODE   |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|                                                   |                          |
|2     N          Y       12       Power Operation  |0        Hot Standby      |
|                                                   |                          |
+------------------------------------------------------------------------------+
                                   EVENT TEXT                                   
+------------------------------------------------------------------------------+
| TECHNICAL SPECIFICATION REQUIRED SHUTDOWN DUE TO A CONTROL BANK OVERLAP      |
| PROBLEM DURING UNIT 2 RESTART                                                |
|                                                                              |
| The following text is a portion of a facsimile received from the licensee:   |
|                                                                              |
| "[At 1301 CDT on 04/15/99, the] Unit 2 reactor was shut down from 12% power  |
| due to control bank overlap not meeting the requirements of Technical        |
| Specification 3.1.6.  Unit 2 was in the process of starting up after a trip  |
| on 04/14/99 due to a generator problem."  (Refer to event #35592 for         |
| additional information.)                                                     |
|                                                                              |
| The licensee stated that all systems functioned as required and that there   |
| was nothing unusual or not understood about this event.  The estimated       |
| restart date is currently unknown.                                           |
|                                                                              |
| The licensee notified the NRC Resident Inspector.                            |
+------------------------------------------------------------------------------+

+------------------------------------------------------------------------------+
|Power Reactor                                    |Event Number:   35596       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: SEQUOYAH                 REGION:  2  |NOTIFICATION DATE: 04/15/1999|
|    UNIT:  [1] [] []                 STATE:  TN |NOTIFICATION TIME: 20:04[EDT]|
|   RXTYPE: [1] W-4-LP,[2] W-4-LP                |EVENT DATE:        04/15/1999|
+------------------------------------------------+EVENT TIME:        16:19[EDT]|
| NRC NOTIFIED BY:  PAUL SIMMONS                 |LAST UPDATE DATE:  04/15/1999|
|  HQ OPS OFFICER:  LEIGH TROCINE                +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          N/A                   |PIERCE SKINNER       R2      |
|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                                   
+------------------------------------------------------------------------------+
| MANUAL STARTING OF THE STANDBY HIGH-HEAD CENTRIFUGAL CHARGING PUMP (CCP) DUE |
| TO FAILURE OF OPERATING PUMP                                                 |
|                                                                              |
| The following text is a portion of a facsimile received from the licensee:   |
|                                                                              |
| "[At approximately] 1619 on 04/15/99, the in-service 1B-B CCP was stopped    |
| after water was identified spraying from the outboard seal.  The leak        |
| stopped when the pump was stopped.  [The main control room unit operator]    |
| had observed increasing amps with decreasing charging flow indicating that   |
| the 1B-B CCP was not functioning [normally].  The 1A-A CCP was placed in     |
| service to maintain [pressurizer] level in the normal operating range and    |
| [to] prevent [pressurizer] level from decreasing to the letdown              |
| isolation/[pressurizer] heater lockout setpoint which could ultimately       |
| [have] lead to a [reactor] trip [and possibly a safety injection] on low     |
| [pressurizer] pressure."                                                     |
|                                                                              |
| The licensee stated that there were no unusual occurrences that were not     |
| understood and that the 1A-A CCP has functioned correctly.  The licensee     |
| also stated that the unit entered three 72-hour technical specification      |
| limiting conditions for operation as a result of this event.  These LCOs     |
| were entered at 1619 EDT.                                                    |
|                                                                              |
| The licensee reported that this event involved a manual actuation of an      |
| engineered safety feature component (1A-A CCP) in response to actual plant   |
| conditions and that this was not a system functional failure.                |
|                                                                              |
| The licensee plans to notify the NRC Resident Inspector.                     |
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