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 THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED !!!!!!!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. |
+------------------------------------------------------------------------------+
