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Event Notification Report for October 19, 1999

                    U.S. Nuclear Regulatory Commission
                              Operations Center

                              Event Reports For
                           10/18/1999 - 10/19/1999

                              ** EVENT NUMBERS **

36218  36285  36299  36305  36306  36307  36308  

+------------------------------------------------------------------------------+
|Power Reactor                                    |Event Number:   36218       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: SUMMER                   REGION:  2  |NOTIFICATION DATE: 09/23/1999|
|    UNIT:  [1] [] []                 STATE:  SC |NOTIFICATION TIME: 17:08[EDT]|
|   RXTYPE: [1] W-3-LP                           |EVENT DATE:        08/06/1999|
+------------------------------------------------+EVENT TIME:        10:00[EDT]|
| NRC NOTIFIED BY:  MICHAEL ZACCONE              |LAST UPDATE DATE:  10/18/1999|
|  HQ OPS OFFICER:  FANGIE JONES                 +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          N/A                   |THOMAS DECKER        R2      |
|10 CFR SECTION:                                 |VERN HODGE (FAX)     NRR     |
|CCCC 21.21               UNSPECIFIED PARAGRAPH  |                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|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                                   
+------------------------------------------------------------------------------+
| 10 CFR PART 21 REPORT - ABB K-LINE BREAKER DEFECT                            |
|                                                                              |
| The following text is a portion of a facsimile received from the licensee:   |
|                                                                              |
| "This report is being made pursuant to 10 CFR 21.21 [in order] to identify a |
| substantial safety hazard with an ABB K-line breaker."                       |
|                                                                              |
| "On August 6, 1999, Virgil C. Summer Nuclear Station (VCSNS) determined that |
| a substantial safety hazard could exist with ABB K-line breakers failing to  |
| trip.  Improper routing/support of the shunt trip wires during refurbishment |
| caused interference with the red trip-shaft paddle on the left side of the   |
| breaker.  This condition was found on a breaker installed in [a]             |
| safety-related switchgear at VCSNS.  This breaker condition was compared to  |
| several other ABB K-line breakers at the plant site.  The other breakers     |
| were found to have the wires routed in a different direction, precluding     |
| interference with the red trip-shaft paddle."                                |
|                                                                              |
| "VCSNS utilizes these breakers in many applications, including the 480-VAC,  |
| safety-related, electrical buses.  The shunt trip wiring problem is          |
| considered a defect in repair.  This condition represents a potential for a  |
| common mode failure for safety-related K-line breakers."                     |
|                                                                              |
| "The vendor has been notified of the shunt trip wiring problem and has       |
| agreed to modify the procedure for the refurbishment of these breakers.      |
| VCSNS Engineering has determined that vendor procedure changes               |
| should prevent recurrence of this problem."                                  |
|                                                                              |
| The licensee notified the NRC resident inspector.                            |
|                                                                              |
| ********************* UPDATE AT 0934 ON 10/18/99 FROM PHIL ROSE TO LEIGH     |
| TROCINE ********************                                                 |
|                                                                              |
| The following text is a portion of a facsimile received from the licensee:   |
|                                                                              |
| "On [10/07/99], ABB Service and VCSNS personnel inspected the affected       |
| breaker along with a second K-line breaker that was determined to also be    |
| potentially affected at VCSNS.  It was determined that the following         |
| information should be provided to all licensees regarding this issue:"       |
|                                                                              |
| "The potentially affected breakers at ABB K-line breakers of the following   |
| type:                                                                        |
| *  all electrically-operated breakers model K-1600, K-1600S, K-2000,         |
| K-2000S, and K-225 through K-800[; and]                                      |
| *  any mechanically- or electrically-operated breakers with the above model  |
| numbers which have any                                                       |
| auxiliary switches or a shunt trip."                                         |
|                                                                              |
| "The potential impact on the breakers has been assessed to be either of the  |
| following:                                                                   |
| *  For breakers having the shunt trip coil wiring on top of the tripper      |
| paddle, a trip free condition could result.                                  |
| *  For breakers which have the shunt trip coil wiring underneath the tripper |
| paddle, the overload trip could be                                           |
| prevented from operating.  The circuit breaker is capable of a manual or     |
| electrical trip.  This condition                                             |
| impacts the overload trip function only."                                    |
|                                                                              |
| "It was also determined that this problem was not limited to the breaker     |
| refurbishment/repair process by ABB Service.  [The licensee stated that this |
| condition could occur on new breakers.]"                                     |
|                                                                              |
| "VCSNS has inspected 26 safety-related breakers.  One breaker was found to   |
| be affected and another potentially affected.  Corrective actions have been  |
| taken.  VCSNS has also inspected three non-safety-related breakers with no   |
| further problems identified.  The remaining breakers (four safety related    |
| and five non-safety related) have been added to the scope of the next        |
| refueling outage."                                                           |
|                                                                              |
| "[Both] VCSNS and ABB Service recommend inspection of all potentially        |
| affected breakers as soon as they can be made available.  The recommended    |
| corrective action is to inspect and secure any wiring that could potentially |
| interfere with the proper operation of the tripper paddle."                  |
|                                                                              |
| The licensee stated that a 30-day report regarding this issue is due to be   |
| issued this week.  The licensee notified the NRC resident inspector.  The    |
| NRC operations officer notified the R1DO (Cook), R2DO (Julian), R3DO         |
| (Jorgensen), R4DO (Smith), and NRR (Hodge).                                  |
+------------------------------------------------------------------------------+

!!!!!!!!! THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED  !!!!!!!
+------------------------------------------------------------------------------+
|Power Reactor                                    |Event Number:   36285       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: PEACH BOTTOM             REGION:  1  |NOTIFICATION DATE: 10/13/1999|
|    UNIT:  [] [3] []                 STATE:  PA |NOTIFICATION TIME: 07:12[EDT]|
|   RXTYPE: [2] GE-4,[3] GE-4                    |EVENT DATE:        10/13/1999|
+------------------------------------------------+EVENT TIME:        03:26[EDT]|
| NRC NOTIFIED BY:  CAMERON CAMPBELL             |LAST UPDATE DATE:  10/18/1999|
|  HQ OPS OFFICER:  FANGIE JONES                 +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          N/A                   |JAMES NOGGLE         R1      |
|10 CFR SECTION:                                 |                             |
|ARPS 50.72(b)(2)(ii)     RPS ACTUATION          |                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR|   INIT RX MODE  |CURR PWR|  CURR RX MODE   |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|                                                   |                          |
|3     N          N       0        Refueling        |0        Refueling        |
|                                                   |                          |
+------------------------------------------------------------------------------+
                                   EVENT TEXT                                   
+------------------------------------------------------------------------------+
| REACTOR TRIP GENERATED DURING TESTING, PLANT ALREADY SHUTDOWN                |
|                                                                              |
| During refueling outage activities a 'Full Scram' signal was initiated while |
| testing the main steam line high radiation instrumentation.  No control rod  |
| or 'Group I' isolation valve movement occurred as a result of this signal    |
| since all affected equipment was in the tripped condition due to plant       |
| conditions.  The only valve movement was the scram discharge volume vent and |
| drain valves which closed per design.                                        |
|                                                                              |
| The 'Full Scram' and 'Group I' isolation signal resulted as a result of      |
| testing inadequacies.  The signal was reset and the valves were opened per   |
| plant procedures.                                                            |
|                                                                              |
| The NRC Resident Inspector was informed.                                     |
|                                                                              |
| * * * RETRACTION AT 1530 ON 10/18/1999 FROM WEILGOPOLSKI TAKEN BY STRANSKY * |
| * *                                                                          |
|                                                                              |
| "This event involved a 4-hour report made for the inadvertent ESF actuation  |
| under 10 CFR 50.72(b)(2)(ii). The event occurred while Unit 3 was in a       |
| refueling outage and involved a full scram signal being initiated during     |
| testing of the main steam line high radiation instrumentation. The event had |
| no control rod movement or Group 1 isolation valve movement since all        |
| affected equipment was in the tripped condition during to refueling          |
| activities. The only valve movement that occurred was the scram discharge    |
| volume (SDV) vent and drain valves which closed.                             |
|                                                                              |
| "Although the SDV vent and drain valves closed and are primary containment   |
| isolation valves, this event is being retracted based on the following:      |
| *     ESF actuation signal was invalid because it was caused by a procedural |
| error; and                                                                   |
| *     the SDV vent and drain valve primary containment function was properly |
| removed from service as a result of                                          |
| [Point Beach Atomic Power Station (PBAPS)] Unit 3 being in a refueling       |
| outage (Mode 5) and the primary                                              |
| containment breached."                                                       |
|                                                                              |
| The NRC resident inspector has been informed of this retraction. The NRC     |
| operations officer notified the R1DO (Cook).                                 |
+------------------------------------------------------------------------------+

+------------------------------------------------------------------------------+
|Power Reactor                                    |Event Number:   36299       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: PALO VERDE               REGION:  4  |NOTIFICATION DATE: 10/16/1999|
|    UNIT:  [1] [2] [3]               STATE:  AZ |NOTIFICATION TIME: 06:55[EDT]|
|   RXTYPE: [1] CE,[2] CE,[3] CE                 |EVENT DATE:        10/16/1999|
+------------------------------------------------+EVENT TIME:        03:05[MST]|
| NRC NOTIFIED BY:  JIM BLAZICK                  |LAST UPDATE DATE:  10/18/1999|
|  HQ OPS OFFICER:  FANGIE JONES                 +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          UNU                   |GAIL GOOD            R4      |
|10 CFR SECTION:                                 |WILLIAM BATEMAN      NRR     |
|AAEC 50.72 (a) (1) (I)   EMERGENCY DECLARED     |FRANK CONGEL         IRO     |
|APRE 50.72(b)(2)(vi)     OFFSITE NOTIFICATION   |RICHE                FEMA    |
|                                                |WILLIAM BRACH        NMSS    |
|                                                |TED MICHAELS         REXB    |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR|   INIT RX MODE  |CURR PWR|  CURR RX MODE   |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|1     N          N       0        Refueling        |0        Refueling        |
|2     N          Y       100      Power Operation  |100      Power Operation  |
|3     N          Y       100      Power Operation  |100      Power Operation  |
+------------------------------------------------------------------------------+
                                   EVENT TEXT                                   
+------------------------------------------------------------------------------+
| UNUSUAL EVENT DECLARED DUE TO EARTHQUAKE FELT ON SITE.  (Refer to event      |
| #36298 for a related event at San Onofre.)                                   |
|                                                                              |
| An earthquake of magnitude 7.0 occurred at 0247 MST at coordinates 34        |
| degrees 35.73 minutes north, 116 degrees 16.09 minutes west.  This location  |
| is about 32 miles north of Joshua Tree, California, and 47 miles             |
| east-southeast of Barstow, California.  This information is from the U.S.    |
| Geological Survey Southern California Seismic Network.                       |
|                                                                              |
| The licensee felt the earthquake, and the strong motion accelerometer        |
| alarmed.  An approximate intensity level of 0.015g's has been determined.    |
| Unit 1 is defueled, and Units 2 and 3 are in operation with no problems.     |
| Inspections were carried out per procedures as well as the declaration of    |
| the Unusual Event.  Engineering walkdowns and evaluations are in progress    |
| per procedure.                                                               |
|                                                                              |
| The Unusual Event was entered and exited at 0305 MST.                        |
|                                                                              |
| The licensee notified the NRC Resident Inspector as well and state/local     |
| authorities.                                                                 |
|                                                                              |
| ***************** UPDATE AT 0100 EDT ON 10/18/99 FROM DANN DAILEY TO LEIGH   |
| TROCINE *****************                                                    |
|                                                                              |
| The following text is a portion of a facsimile received from the licensee:   |
|                                                                              |
| "This is a followup of the ENS notification at 0353 MST on 10/16/99.  If     |
| through subsequent reviews of this event, additional information is          |
| identified that is pertinent to this event or alters the information being   |
| provided at this time, another followup notification will be made via the    |
| ENS or under the reporting requirements of 10CFR50.73."                      |
|                                                                              |
| "On [10/16/99], at approximately 0247 MST, an earthquake, referred to as the |
| 'Hector Earthquake,' of approximate magnitude 7.0 occurred, its epicenter    |
| located about 32 miles north of Joshua Tree, California.  Joshua Tree,       |
| California is located approximately 220 miles west of the Palo Verde Nuclear |
| Generating Station.  At approximately 0248 MST, the vibratory ground motion  |
| reached and actuated the Palo Verde Seismic Monitoring Instrumentation       |
| switches.  Specifically, the strong motion accelerometer trigger located in  |
| the Unit 1 containment building tendon gallery exceeded the threshold value  |
| of 0.01g.  The vibratory ground motion also was felt by personnel in all     |
| three Palo Verde control rooms.  Operations personnel immediately retrieved  |
| data from the actuated instrument and performed analysis to determine the    |
| magnitude of the vibratory ground motion.  Initial analysis of the Seismic   |
| Monitoring Instrumentation tape recordings completed at approximately 0305   |
| MST indicated a seismic event of about 0.015g.  This is well below the       |
| magnitude of the 0.10g spectra Operating Basis Earthquake (OBE) and the      |
| 0.20g spectra Safe Shutdown Earthquake (SSE).  Based on the validation of    |
| the earthquake per the Emergency Action Level 6.6 Technical Bases, the Unit  |
| 1 Shift Manager declared (and immediately exited due to the event being      |
| over) a Notification of an Unusual Event (NUE) applicable to all three units |
| due to a seismic event."                                                     |
|                                                                              |
| "The NRC was notified at 0353 MST on 10/16/99 via the Emergency Notification |
| System (ENS).  The criteria for the ENS notification were                    |
| 10CFR50.72(a)(1)(i) due to the declaration of an Emergency Class and         |
| 10CFR50.72(b)(1)(iii) due to the natural phenomenon that poses an actual     |
| threat to the safety of the nuclear power plant.  Further analysis of the    |
| seismic data concluded the measured motions of structures and components     |
| were less than 14% of the OBE and should have no effect upon facility        |
| features important to safety.  Based on the low magnitude of the vibratory   |
| ground motion and satisfactory plant walkdowns, an actual threat to safety   |
| did not exist.  The ENS notification per 10CFR50.72(b)(1)(iii) is hereby     |
| retracted.  The initial notification stated a press release was expected to  |
| be made; therefore, 10CFR50.72(b)(2)(vi) also applied.  No media interest    |
| existed; therefore, no press release was made.  The ENS notification per     |
| 10CFR50.72(a)(1)(i) remains valid."                                          |
|                                                                              |
| "Following declaration of the NUE, the Maricopa County Sheriff's Office and  |
| the Arizona Department of Public Safety were notified at approximately 0313  |
| MST via the Notification and Alert Network (NAN).  The Palo Verde Emergency  |
| Coordinator recommended that no protective actions be taken.  No protective  |
| actions were implemented by state or county agencies."                       |
|                                                                              |
| "Operations personnel performed an immediate walkdown of plant equipment.    |
| No abnormalities caused by the seismic event were observed.  There were no   |
| structures, systems, or components that were inoperable that contributed to  |
| this event.  There were no failures that rendered a train of a safety system |
| inoperable, and no failures of components with multiple functions were       |
| involved.  No engineered safety feature (ESF) actuations occurred, and none  |
| were required.  The event did not result in any challenges to the fission    |
| product barrier or result in any releases of radioactive materials.  The     |
| event did not adversely affect the safe operation of the plant or health and |
| safety of the public."                                                       |
|                                                                              |
| The licensee notified the NRC resident inspector.  The NRC operations        |
| officer notified the R4DO (Good), NRR EO (Bateman), and IRO (Congel).        |
+------------------------------------------------------------------------------+

+------------------------------------------------------------------------------+
|Power Reactor                                    |Event Number:   36305       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: BYRON                    REGION:  3  |NOTIFICATION DATE: 10/18/1999|
|    UNIT:  [1] [2] []                STATE:  IL |NOTIFICATION TIME: 12:53[EDT]|
|   RXTYPE: [1] W-4-LP,[2] W-4-LP                |EVENT DATE:        10/18/1999|
+------------------------------------------------+EVENT TIME:        10:55[CDT]|
| NRC NOTIFIED BY:  SCOTT SWANSON                |LAST UPDATE DATE:  10/18/1999|
|  HQ OPS OFFICER:  BOB STRANSKY                 +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          N/A                   |BRUCE JORGENSEN      R3      |
|10 CFR SECTION:                                 |                             |
|BAAA 20.1906(d)           SURFACE CONT/ EXT RAD |                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|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       93       Power Operation  |93       Power Operation  |
|                                                   |                          |
+------------------------------------------------------------------------------+
                                   EVENT TEXT                                   
+------------------------------------------------------------------------------+
| SHIPMENT RECEIVED WITH SURFACE CONTAMINATION IN EXCESS OF SHIPPING LIMITS.   |
|                                                                              |
| A shipment containing a portable demineralizer resin tank received from the  |
| Point Beach Nuclear Station had external removable contamination in excess   |
| of shipping limits. Smears taken from the shipment were placed in a          |
| radiation detector, and readings of up to 52,800 dpm were observed. The      |
| licensee has contacted the shipper (Hitman).                                 |
|                                                                              |
| The NRC resident inspector has been informed of this event by the licensee.  |
+------------------------------------------------------------------------------+

+------------------------------------------------------------------------------+
|Hospital                                         |Event Number:   36306       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| REP ORG:  ST. JOHN'S HOSPITAL                  |NOTIFICATION DATE: 10/18/1999|
|LICENSEE:  ST. JOHN'S HOSPITAL                  |NOTIFICATION TIME: 14:35[EDT]|
|    CITY:  DETROIT                  REGION:  3  |EVENT DATE:        09/07/1999|
|  COUNTY:                            STATE:  MI |EVENT TIME:             [EDT]|
|LICENSE#:  21-03210-01           AGREEMENT:  N  |LAST UPDATE DATE:  10/18/1999|
|  DOCKET:                                       |+----------------------------+
|                                                |PERSON          ORGANIZATION |
|                                                |BRUCE JORGENSEN      R3      |
|                                                |BRIAN SMITH          NMSS    |
+------------------------------------------------+                             |
| NRC NOTIFIED BY:  WALTER NIKESCH               |                             |
|  HQ OPS OFFICER:  BOB STRANSKY                 |                             |
+------------------------------------------------+                             |
|EMERGENCY CLASS:          N/A                   |                             |
|10 CFR SECTION:                                 |                             |
|LADM 35.33(a)            MED MISADMINISTRATION  |                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
+------------------------------------------------------------------------------+

                                   EVENT TEXT                                   
+------------------------------------------------------------------------------+
| MEDICAL MISADMINISTRATION                                                    |
|                                                                              |
| While performing a monthly audit, the licensee discovered that a patient,    |
| who had been prescribed a dose of 200 mCi of I-131 for thyroid ablation, was |
| administered a dose of 264 mCi of I-131. The misadministration occurred on   |
| 9/7/1999.  The attending physician has been informed of the                  |
| misadministration. The licensee has also contacted NRC Region III (J.        |
| Cameron).                                                                    |
+------------------------------------------------------------------------------+

+------------------------------------------------------------------------------+
|General Information or Other                     |Event Number:   36307       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| REP ORG:  CALIFORNIA RADIATION CONTROL PRGM    |NOTIFICATION DATE: 10/18/1999|
|LICENSEE:  MILLER PACIFIC ENGINEERING GROUP     |NOTIFICATION TIME: 19:00[EDT]|
|    CITY:  SANTA ROSA               REGION:  4  |EVENT DATE:        10/18/1999|
|  COUNTY:                            STATE:  CA |EVENT TIME:        02:00[PDT]|
|LICENSE#:  5411-21 (CA)          AGREEMENT:  Y  |LAST UPDATE DATE:  10/18/1999|
|  DOCKET:                                       |+----------------------------+
|                                                |PERSON          ORGANIZATION |
|                                                |LINDA SMITH          R4      |
|                                                |WAYNE HODGES         NMSS    |
+------------------------------------------------+                             |
| NRC NOTIFIED BY:  DONALD BUNN                  |                             |
|  HQ OPS OFFICER:  BOB STRANSKY                 |                             |
+------------------------------------------------+                             |
|EMERGENCY CLASS:          N/A                   |                             |
|10 CFR SECTION:                                 |                             |
|NAGR                     AGREEMENT STATE        |                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
|                                                |                             |
+------------------------------------------------------------------------------+

                                   EVENT TEXT                                   
+------------------------------------------------------------------------------+
| STOLEN MOISTURE/DENSITY GAUGE                                                |
|                                                                              |
| A representative of the California State Radiation Control Program reported  |
| the theft of a CPM Model MC-1DR moisture/density gauge from a state          |
| licensee. The gauge contains one 10-mCi Cs-137 source, and one 40-mCi        |
| Am-241/Be source. The local police are investigating the theft and plan to   |
| file a report with the state. The licensee has issued a press release        |
| regarding the theft.                                                         |
+------------------------------------------------------------------------------+

+------------------------------------------------------------------------------+
|Power Reactor                                    |Event Number:   36308       |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: COOPER                   REGION:  4  |NOTIFICATION DATE: 10/18/1999|
|    UNIT:  [1] [] []                 STATE:  NE |NOTIFICATION TIME: 20:28[EDT]|
|   RXTYPE: [1] GE-4                             |EVENT DATE:        10/18/1999|
+------------------------------------------------+EVENT TIME:        15:12[CDT]|
| NRC NOTIFIED BY:  WILLIAM B. GREEN             |LAST UPDATE DATE:  10/18/1999|
|  HQ OPS OFFICER:  BOB STRANSKY                 +-----------------------------+
+------------------------------------------------+PERSON          ORGANIZATION |
|EMERGENCY CLASS:          N/A                   |LINDA SMITH          R4      |
|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                                   
+------------------------------------------------------------------------------+
| SPURIOUS BUS UNDERVOLTAGE ALARM CAUSES VARIOUS ESF ACTUATIONS.               |
|                                                                              |
| "At 1512 CDT on 10/18/99, 4160 bus 1B [undervoltage annunciator] alarmed and |
| 4160 bus 1B breaker 1BG, the normal power supply to essential 4160 bus 1G,   |
| tripped. The emergency transformer, through breaker 1GS, began supplying     |
| power to essential 4160 bus 1G. Diesel generator #2 automatically started on |
| the undervoltage condition but did not load since essential bus 1G was being |
| supplied by the emergency transformer as designed.                           |
|                                                                              |
| "Primary containment isolation system (PCIS) Group isolations for [the]      |
| reactor water cleanup system and reactor building isolation occurred due to  |
| a loss of power. Emergency Operating Procedure 5A, Secondary Containment     |
| Control, was entered due to reactor building pressure going positive, the    |
| maximum value reached during the transient was +0.01 inches water gage. Both |
| trains of standby gas treatment started on the Group 6 isolation and         |
| returned reactor building pressure to a negative value.                      |
|                                                                              |
| "PCIS Group Isolations 2 and 7 had some valves reposition. These valves were |
| consistent with valves that would reposition on a loss of power. However,    |
| two valves normally actuated by a half group isolation on the division 2     |
| side did not reposition. It is believed that this condition occurred due to  |
| the speed of actuation of relays in the PCIS system and is being             |
| investigated.                                                                |
|                                                                              |
| "Circulating water pump 1C tripped during the transient, and the steam jet   |
| air ejectors (SJAE) isolated during the electrical transient. These          |
| conditions caused main condenser vacuum to lower to a point that the turbine |
| generator low vacuum pre-trip alarm was received at 25 inches Hg lowering.   |
| The SJAEs were reset, and vacuum in the main condenser began to rise. The    |
| lowest vacuum indicated was 24.5 inches Hg. Vacuum is currently 26.5 inches  |
| Hg.                                                                          |
|                                                                              |
| "At the time of the event, Electrical Maintenance Personnel were installing  |
| monitoring equipment in the condensate pump B cubicle.                       |
|                                                                              |
| "4160 Bus 1G is currently being supplied from the emergency transformer, and |
| diesel generator #2 [was] returned to a normal standby lineup at 1634 [CDT]. |
| The electrical grid is stable, and the reactor and secondary plant are in a  |
| stable condition.                                                            |
|                                                                              |
| "The undervoltage alarm for 4160 bus 1B is still actuated even though an     |
| actual undervoltage does not exist on the bus. A team of personnel is        |
| investigating the undervoltage condition at this time."                      |
|                                                                              |
| The NRC resident inspector has been informed of this event by the licensee.  |
+------------------------------------------------------------------------------+