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Event Notification Report for September 5, 2001

                    U.S. Nuclear Regulatory Commission
                              Operations Center

                              Event Reports For
                           09/04/2001 - 09/05/2001

                              ** EVENT NUMBERS **

38263  38264  38265  

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|Power Reactor                                    |Event Number:   38263       |
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| FACILITY: WATTS BAR                REGION:  2  |NOTIFICATION DATE: 09/04/2001|
|    UNIT:  [1] [] []                 STATE:  TN |NOTIFICATION TIME: 16:54[EDT]|
|   RXTYPE: [1] W-4-LP,[2] W-4-LP                |EVENT DATE:        09/04/2001|
+------------------------------------------------+EVENT TIME:        13:04[EDT]|
| NRC NOTIFIED BY:  RODEN                        |LAST UPDATE DATE:  09/04/2001|
|  HQ OPS OFFICER:  CHAUNCEY GOULD               +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          NON EMERGENCY         |JOHN MONNINGER       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      |
|                                                   |                          |
|                                                   |                          |
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                                   EVENT TEXT                                   
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| REACTOR MANUALLY TRIPPED FROM 100% POWER DUE TO STEAM GENERATOR LEVEL        |
| APPROACHING THE LO-LO LEVEL SETPOINT                                         |
|                                                                              |
| While operating at 100% power, the Watts Bar Unit 1 reactor was manually     |
| tripped at approximately 1304 EDT on September 4, 2001 due to steam          |
| generator (SG) level approaching the Lo-Lo level setpoint.  Just prior to    |
| the manual trip of the reactor, an abnormal voltage alarm was received on    |
| 125V Vital Battery Board 1-1.  The immediate cause of the trip is considered |
| to be the loss of the 1-1 Vital AC Inverter which caused a feedwater         |
| regulating valve to close.   Subsequently, the maintenance power supply was  |
| used to restore power to the 1-1 vital AC bus.                               |
|                                                                              |
| All control rods inserted properly in response to the reactor trip.  The     |
| Auxiliary Feedwater (AFW) System actuated as expected.  However, subsequent  |
| to the initial actuation signal, additional operator action was required     |
| to[manually] start 1B motor driven pump.   After the 1B pump was             |
| successfully started, the motor driven AFW pump 1A was secured based on      |
| instrument indications available to the operating staff.   After power was   |
| restored to the vital AC bus, the 1A pump was subsequently started and       |
| performed properly.   Inspections are currently underway to determine the    |
| exact cause of the loss of the 1-1 Vital Inverter and basis for the 1B pump  |
| failing to [auto] start.                                                     |
|                                                                              |
| No ECCS injection occurred, but the steam generator atmospheric relief       |
| valves lifted and fully reseated.                                            |
|                                                                              |
| The manual actuation of the Reactor Protection System (RPS) is being         |
| reported as a four hour report under 10 CFR 50.72 (b)(2)(iv).  The actuation |
| of the Auxiliary Feedwater System (an engineered safety feature) is being    |
| reported as an eight hour report under 10 CFR 50.72 (b)(3)(iv).              |
|                                                                              |
| The plant is stable in mode 3.                                               |
|                                                                              |
| The NRC Resident Inspector was notified.                                     |
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|Power Reactor                                    |Event Number:   38264       |
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| FACILITY: CALVERT CLIFFS           REGION:  1  |NOTIFICATION DATE: 09/04/2001|
|    UNIT:  [1] [2] []                STATE:  MD |NOTIFICATION TIME: 17:00[EDT]|
|   RXTYPE: [1] CE,[2] CE                        |EVENT DATE:        09/04/2001|
+------------------------------------------------+EVENT TIME:        15:00[EDT]|
| NRC NOTIFIED BY:  LAVATE                       |LAST UPDATE DATE:  09/04/2001|
|  HQ OPS OFFICER:  CHAUNCEY GOULD               +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          NON EMERGENCY         |HAROLD GRAY          R1      |
|10 CFR SECTION:                                 |                             |
|ACOM 50.72(b)(3)(xiii)   LOSS COMM/ASMT/RESPONSE|                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|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  |
|                                                   |                          |
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                                   EVENT TEXT                                   
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| FAILURE OF 17 OUT OF THE 49 EMERGENCY NOTIFICATION SYSTEM SIRENS FOR CALVERT |
| COUNTY                                                                       |
|                                                                              |
| The licensee reported that 17 out of 49 sirens in Calvert County failed to   |
| respond to the scheduled county test..   However, all sirens did respond to  |
| a mobile siren test kit which is used locally at the siren.  Calvert County  |
| Emergency Management was notified to perform route alerting in the affected  |
| areas in the event of an emergency.   The cause is believed to be a          |
| transmission problem.                                                        |
|                                                                              |
| The NRC Resident Inspector will be notified.  The county has been notified.  |
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|Fuel Cycle Facility                              |Event Number:   38265       |
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| FACILITY: PADUCAH GASEOUS DIFFUSION PLANT      |NOTIFICATION DATE: 09/04/2001|
|   RXTYPE: URANIUM ENRICHMENT FACILITY          |NOTIFICATION TIME: 18:09[EDT]|
| COMMENTS: 2 DEMOCRACY CENTER                   |EVENT DATE:        09/04/2001|
|           6903 ROCKLEDGE DRIVE                 |EVENT TIME:        14:00[CDT]|
|           BETHESDA, MD 20817    (301)564-3200  |LAST UPDATE DATE:  09/04/2001|
|    CITY:  PADUCAH                  REGION:  3  +-----------------------------+
|  COUNTY:  McCRACKEN                 STATE:  KY |PERSON          ORGANIZATION |
|LICENSE#:  GDP-1                 AGREEMENT:  Y  |MARK RING            R3      |
|  DOCKET:  0707001                              |M. WAYNE HODGES      NMSS    |
+------------------------------------------------+                             |
| NRC NOTIFIED BY:  UNDERWOOD                    |                             |
|  HQ OPS OFFICER:  CHAUNCEY GOULD               |                             |
+------------------------------------------------+                             |
|EMERGENCY CLASS:          NON EMERGENCY         |                             |
|10 CFR SECTION:                                 |                             |
|NBNL                     RESPONSE-BULLETIN      |                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
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                                   EVENT TEXT                                   
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| 24-HOUR 91-01 BULLETIN RESPONSE                                              |
|                                                                              |
| At 1400, on 9/4/01, the Plant Shift Superintendent (PSS) was notified of an  |
| NCSA violation that had occurred at the C-355 air plant.  Immediately after  |
| switching drying units at the air plant, a high-high moisture alarm was      |
| received.  The alarm indicated air moisture content greater than 1300 ppm    |
| water, violating NCSA GEN-10-01.  NCSA GEN-010 credits the dry air system    |
| for producing dry air with moisture content of less than 1300 ppm.  The      |
| purpose of this requirement is to prevent exposure of fissile uranium        |
| deposits to a moderating environment.   No equipment containing fissile      |
| material was exposed to high moisture content plant air at the time of the   |
| alarm or following receipt of the alarm.                                     |
|                                                                              |
| Since one leg of double contingency was lost, this is being reported to the  |
| NRC as a 24-hr. event report.                                                |
|                                                                              |
| SAFETY SIGNIFICANCE OF EVENTS:                                               |
| There was no purging of equipment containing fissile material in progress at |
| the time of the moisture excursion.  Although a parameter was exceeded, the  |
| proper response to the alarm was taken prior to resuming buffering of        |
| purging equipment containing fissile material.                               |
|                                                                              |
| POTENTIAL CRITICALITY PATHWAYS INVOLVED(BRIEF SCENARIO(S) OF HOW CRITICALITY |
| COULD OCCUR:                                                                 |
| In order for a criticality to be possible. Operations personnel would have   |
| had to fail to respond to the alarm. In addition, a fissile deposit          |
| containing greater than a critical mass and absorbing greater than 10 kg of  |
| water would have had to be present.                                          |
|                                                                              |
| CONTROLLED PARAMETERS (MASS, MODERATION. GEOMETRY, CONCENTRATION. ETC:       |
| Double contingency for this scenario is established by implementing two      |
| controls on moderation.                                                      |
|                                                                              |
| ESTIMATED AMOUNT, ENRICHMENT, FORM OF LICENSED MATERIAL (INCLUDE PROCESS     |
| LIMIT AND % WORST CASE CRITICAL MASS):                                       |
| n/a                                                                          |
|                                                                              |
| NUCLEAR CRITICALITY SAFETY CONTROL(S) OR CONTROL SYSTEM(S) AND DESCRIPTION   |
| OF THE FAILURES OR  DEFICIENCIES:                                            |
| Double contingency for this scenario is established by implementing two      |
| controls on moderation.                                                      |
|                                                                              |
| The first leg of double contingency Is based on receiving a high-high        |
| moisture alarm indicating a moisture content greater than 1300 ppm water and |
| ceasing buffering and purging operations in response to the alarm. This      |
| control was not violated.                                                    |
|                                                                              |
| The second leg of double contingency is based on the dry air system          |
| producing plant air with a moisture content less than 1300 ppm water. Since  |
| the moisture content was confirmed to be greater than 1300 ppm, this process |
| condition was exceeded and double contingency was not maintained.            |
|                                                                              |
| Since double contingency is based on two controls on moderation, double      |
| contingency was not maintained.                                              |
|                                                                              |
| CORRECTIVE ACTIONS TO RESTORE SAFETY SYSTEMS AND WHEN EACH WAS IMPLEMENTED:  |
| No corrective actions implemented. Proper procedure response was performed.  |
|                                                                              |
| The NRC Resident Inspector was notified.                                     |
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