Event Notification Report for March 30, 1999
U.S. Nuclear Regulatory Commission
Operations Center
Event Reports For
03/29/1999 - 03/30/1999
** EVENT NUMBERS **
35400 35513 35517 35521 35522 35523 35524 35525
!!!!!!!!! THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED !!!!!!!
+------------------------------------------------------------------------------+
|Power Reactor |Event Number: 35400 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: VERMONT YANKEE REGION: 1 |NOTIFICATION DATE: 02/24/1999|
| UNIT: [1] [] [] STATE: VT |NOTIFICATION TIME: 19:19[EST]|
| RXTYPE: [1] GE-4 |EVENT DATE: 02/24/1999|
+------------------------------------------------+EVENT TIME: 19:07[EST]|
| NRC NOTIFIED BY: JIM BROOKS |LAST UPDATE DATE: 03/29/1999|
| HQ OPS OFFICER: FANGIE JONES +-----------------------------+
+------------------------------------------------+PERSON ORGANIZATION |
|EMERGENCY CLASS: N/A |RICHARD BARKLEY R1 |
|10 CFR SECTION: | |
|AOUT 50.72(b)(1)(ii)(B) OUTSIDE DESIGN BASIS | |
|NLCO TECH SPEC LCO A/S | |
| | |
| | |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|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
+------------------------------------------------------------------------------+
| TORUS WATER LEVEL DETERMINED TO BE OUTSIDE DESIGN BASIS DUE TO INSTRUMENT |
| ERROR |
| |
| The following text is a portion of a facsimile received from the licensee: |
| |
| "During the design installation of a more accurate narrow range torus level |
| instrument, as part of our [basis for maintaining operations] process, it |
| was identified that the current level indication was 1.5 inches lower than |
| actual level. Under these conditions we had the potential to be slightly |
| outside the acceptable torus operating level band high. At this time, we |
| are within the Tech Spec limit but outside our administrative limit. With |
| the 1.5-inch discrepancy, it is likely that in the past we have unknowingly |
| operated outside the Tech Spec limit for more than 24 hours. |
| |
| "We don't feel that this is of a significant safety concern since even with |
| the 1.5-inch error, the torus level would only have been approximately 1/2 |
| inch outside the Tech Spec limit. This would still be greater than three |
| feet below a level where emergency depressurization would be required by the |
| emergency operating procedures. |
| |
| "The new indication installed by the design process has been declared |
| operable, and the instrument in error |
| has been declared inoperable. The plant has entered a 24-hour shutdown |
| [limiting condition for operation (LCO)] for being outside our |
| administrative limit as required by plant procedures. Plans are in place to |
| lower torus water level to within administrative limits and exit the 24-hour |
| LCO." |
| |
| The licensee notified the NRC Resident Inspector. |
| |
| * * * RETRACTION 1011 3/29/1999 FROM SALTWELL TAKEN BY STRANSKY * * * |
| |
| "VY has been operating since its 05/98 outage with an administrative limit |
| that credited in-place torus narrow-range level instrument uncertainties as |
| <= 1.0 inches. On 02/24/99, VY installed a new torus water level indication |
| system. Upon energizing the new level indication system, it was noted that |
| there existed a disparity between the in-place/operable level indication |
| instrumentation and the new instrument. The difference between the original |
| and operable level indication, and the newly installed instrument was |
| approximately 1.5 inches. It was believed at that time that the new |
| instrument indication was very close to actual torus level. |
| |
| "Upon observing the variance between the new and old indications, VY made |
| the conservative determination that the new instrument was indicating actual |
| torus level, completed the necessary testing, declared the new system |
| operable, and began controlling level based upon that indication. |
| |
| "It was concluded that the instrument uncertainty must have been |
| significantly higher than the 1 inch credited for operation following the |
| 05/98 outage, indicating up to 1.5 inches below actual level. Were this |
| true VY would have been operating with a torus water volume greater than |
| allowed by its Technical Specifications for periods greater than those |
| Technical Specifications allow. It was further concluded that such |
| operation may have invalidated the conclusions of several VY calculations |
| and analyses which demonstrate the adequacy of the VY Primary Containment |
| System. VY therefore made an ENS notification for operation outside of the |
| design basis of the plant. |
| |
| "On 02/25/99, VY installed, and placed in service, a second high accuracy |
| torus level indication instrument. The two new instruments unexpectedly |
| showed a 0.5 inch difference between one another. The 1 inch administrative |
| margin to TS maximum and minimum levels were still in place; therefore, |
| there was no immediate operability concern. |
| |
| "An evaluation was performed on 03/11/99 using temporary stand-pipes to |
| determine the actual torus water level and thereby determine the accuracy of |
| the newly installed instrumentation. That evaluation concluded that the |
| first new instrument (activated on 02/24/99) had been consistently |
| indicating approximately 0.5 inches higher than actual level. |
| |
| "This evaluation revealed that the report made on 02/24/99 was not required. |
| The actual instrument inaccuracy identified on 03/11/99 indicated that the |
| administrative limits in place since the 05/98 outage accounted for all but |
| 0.08 inches of the maximum error observed in the instrumentation used to |
| control torus water volume. |
| |
| "Plant operating logs taken since the 05/98 plant start up were reviewed. |
| The logs show that VY operated consistent with its Technical |
| Specifications. |
| |
| "The maximum error observed (0.08 inches) was evaluated in light of the |
| analyses and calculations used to verify the adequacy of the Vermont Yankee |
| Primary Containment. In no case did this minor variance challenge the |
| conclusions of any of the analyses/calculations. |
| |
| "Therefore, it was concluded that the conditions were not inconsistent with |
| the design bases of the VY plant, and the report made on 02/24/99 is being |
| retracted." |
| |
| The licensee will inform the NRC resident inspector of this retraction. |
| Notified R1DO (K. Modes). |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
|Fuel Cycle Facility |Event Number: 35513 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: PORTSMOUTH GASEOUS DIFFUSION PLANT |NOTIFICATION DATE: 03/25/1999|
| RXTYPE: URANIUM ENRICHMENT FACILITY |NOTIFICATION TIME: 18:16[EST]|
| COMMENTS: 2 DEMOCRACY CENTER |EVENT DATE: 03/25/1999|
| 6903 ROCKLEDGE DRIVE |EVENT TIME: 10:03[EST]|
| BETHESDA, MD 20817 (301)564-3200 |LAST UPDATE DATE: 03/29/1999|
| CITY: PIKETON REGION: 3 +-----------------------------+
| COUNTY: PIKE STATE: OH |PERSON ORGANIZATION |
|LICENSE#: GDP-2 AGREEMENT: N |MELVYN LEACH R3 |
| DOCKET: 0707002 |ROBERT PIERSON NMSS |
+------------------------------------------------+ |
| NRC NOTIFIED BY: J. B. HALCOMB | |
| HQ OPS OFFICER: FANGIE JONES | |
+------------------------------------------------+ |
|EMERGENCY CLASS: N/A | |
|10 CFR SECTION: | |
|NCFR NON CFR REPORT REQMNT | |
| | |
| | |
| | |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| VALID ACTUATION OF A 'Q' SAFETY SYSTEM |
| |
| "At 1003 hours on March 25, 1999, during normal charging of cell 31-3-3 |
| prior to placing onstream, an Operations |
| Front Line Manager was investigating a Cascade Automatic Data Processing |
| smokehead alarm from this cell when a second smokehead alarmed. He than saw |
| what appeared to be smoke above the Stage 6 area. |
| |
| "All personnel in the area immediately evacuated, implemented the 'See & |
| Flee' Procedure, activated the building recall system, and notified |
| Emergency Response Forces. The cell was taken offstream and cell pressure |
| was reduced below atmosphere. |
| |
| "All airborne and surface contamination sample results were less than |
| detectable and there was no release of |
| Hazardous/Radioactive material or Radioactive/Radiological contamination |
| exposure as a result of this event." |
| |
| The facility notified the NRC Resident Inspector and the DOE Site Manager. |
| |
| * * * UPDATE 1112 3/29/1999 FROM VANDERPOOL TAKEN BY STRANSKY * * * |
| |
| The original report was reissued with the following change to the third |
| paragraph above: |
| |
| "All airborne and surface contamination sample results were less than |
| detectable, and there was no Radioactive/Radiological contamination |
| exposure as a result of this event." |
| |
| HOO notified R3DO (Ring). |
+------------------------------------------------------------------------------+
!!!!!!!!! THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED !!!!!!!
+------------------------------------------------------------------------------+
|Power Reactor |Event Number: 35517 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: PERRY REGION: 3 |NOTIFICATION DATE: 03/27/1999|
| UNIT: [1] [] [] STATE: OH |NOTIFICATION TIME: 07:04[EST]|
| RXTYPE: [1] GE-6 |EVENT DATE: 03/27/1999|
+------------------------------------------------+EVENT TIME: 06:05[EST]|
| NRC NOTIFIED BY: ALAN RABENOLD |LAST UPDATE DATE: 03/29/1999|
| HQ OPS OFFICER: BOB STRANSKY +-----------------------------+
+------------------------------------------------+PERSON ORGANIZATION |
|EMERGENCY CLASS: N/A |MELVYN LEACH 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 |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|1 N N 0 Hot Shutdown |0 Hot Shutdown |
| | |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| RHR PUMP FAILS TO START |
| |
| While attempting to place the unit onto RHR shutdown cooling, the 'A' RHR |
| pump failed to start. The unit is currently in Condition 3 at 227�F, and the |
| main condenser is being used to remove decay heat. The licensee suspects |
| that the failure of the pump to start may be due to a problem with a pump |
| interlock. The licensee is currently troubleshooting the pump. |
| |
| The licensee entered Technical Specification Action Statement 3.0.3 due to |
| the unavailability of shutdown cooling loop 'A'. The unit was shut down |
| overnight in order to commence a refueling outage. The licensee will inform |
| the NRC resident inspector of this report. |
| |
| ***RETRACTION ON 03/29/99 AT 1603 ET BY S. SANFORD TAKEN BY MACKINNON*** |
| |
| At 0704, an entry was made into Technical Specification 3.0.3 due to the 1 |
| hour action of not verifying that a second alternate decay heat removal |
| system was available within the 1 hour. A 1 hour non-emergency report was |
| made to the NRC under 50.72 (b)(1)(I)(A), Tech Spec shutdown. The reactor |
| was already shutdown, and this event is not reportable under this criterion. |
| This is in accordance with the guidance in NUREG 1022, Event Reporting |
| Guidelines 10 CFR 50.72 and 50.73. |
| |
| The Technical Specification bases states that "it is also required to reduce |
| reactor temperature to the point where mode 4 is entered." This statement |
| was incorrectly determined to apply to the requirements of a Decay Heat |
| Removal system. The "it" in this case refers to the requirement of the |
| required action A.3 to be in mode 4 within 24 hours. |
| |
| Therefore, the action requirement to have TWO Alternate Decay Heat Removal |
| methods to maintain or reduce temperature was met within the required time |
| limit of 1 hour. The entry into Technical Specification 3.0.3 was not |
| required. |
| |
| The failure of RHR "A" to start was determined to be a faulty optical |
| isolator in the suction path logic, which was replaced. The RHR "A" |
| subsystem was restarted in the Shutdown Cooling mode, and Mode 4 was reached |
| at 1148 hours. R3DO (Mark Ring) notified. |
| |
| The NRC Resident Inspector was notified of this retraction by the licensee. |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
|General Information or Other |Event Number: 35521 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| REP ORG: ILLINOIS DEPT OF NUCLEAR SAFETY |NOTIFICATION DATE: 03/29/1999|
|LICENSEE: PROVENA- ST JOSEPH MED CTR |NOTIFICATION TIME: 08:57[EST]|
| CITY: JOLIET REGION: 3 |EVENT DATE: 03/25/1999|
| COUNTY: STATE: IL |EVENT TIME: [CST]|
|LICENSE#: IL-01326-01 AGREEMENT: Y |LAST UPDATE DATE: 03/29/1999|
| DOCKET: |+----------------------------+
| |PERSON ORGANIZATION |
| |PATRICK HILAND R3 |
| |LARRY CAMPER NMSS |
+------------------------------------------------+ |
| NRC NOTIFIED BY: PATRICIA LARKINS (OSP) | |
| HQ OPS OFFICER: BOB STRANSKY | |
+------------------------------------------------+ |
|EMERGENCY CLASS: N/A | |
|10 CFR SECTION: | |
|NAGR AGREEMENT STATE | |
| | |
| | |
| | |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| AGREEMENT STATE REPORT |
| |
| The following is a compilation of information sent to the Operations Center |
| by the Office of State Programs: |
| |
| The RSO from the Provena-St. Joseph Medical Center reported that a decay |
| error involving an HDR source resulted in a 31% underdose to three patients |
| (53 year old female, 43 year old female, and 60 year old male). The apparent |
| cause was the use of the certificate activity instead of the current |
| activity for the dose planning. The device was a Nucletron Microselectron |
| HDR with an Ir-192 source. The source had recently been replaced by |
| Nucletron. |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
|Power Reactor |Event Number: 35522 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: BRUNSWICK REGION: 2 |NOTIFICATION DATE: 03/29/1999|
| UNIT: [] [2] [] STATE: NC |NOTIFICATION TIME: 11:35[EST]|
| RXTYPE: [1] GE-4,[2] GE-4 |EVENT DATE: 03/29/1999|
+------------------------------------------------+EVENT TIME: 08:37[EST]|
| NRC NOTIFIED BY: MARK SCHALL |LAST UPDATE DATE: 03/29/1999|
| HQ OPS OFFICER: BOB STRANSKY +-----------------------------+
+------------------------------------------------+PERSON ORGANIZATION |
|EMERGENCY CLASS: N/A |MARK LESSER R2 |
|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 97 Power Operation |0 Hot Shutdown |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| AUTOMATIC TURBINE TRIP/REACTOR SCRAM DUE TO SPURIOUS HIGH VIBRATION SIGNAL |
| |
| The unit received an automatic turbine trip/reactor scram due to a suspected |
| spurious turbine high vibration signal. Following the scram, all control |
| rods inserted, and all systems functioned as expected. Two safety/relief |
| valves lifted but immediately reseated. Primary Containment Isolation System |
| (PCIS) Group 2 (drywell equipment and floor drains, TIP, radwaste, and |
| process sampling), 6 (containment atmosphere and post-accident sampling), |
| and 8 (RHR shutdown cooling) isolations occurred due to reactor vessel water |
| level shrinkage following the scram. Reactor vessel water level recovered |
| shortly after the scram. |
| |
| The licensee is currently investigating the cause of the turbine vibration |
| signal. The NRC resident inspector has been informed of this event by the |
| licensee. |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
|Other Nuclear Material |Event Number: 35523 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| REP ORG: FLORIDA BUREAU OF RADIATION CONTROL |NOTIFICATION DATE: 03/29/1999|
|LICENSEE: H.W. LOCHNER |NOTIFICATION TIME: 12:45[EST]|
| CITY: CLEARWATER REGION: 2 |EVENT DATE: 03/29/1999|
| COUNTY: STATE: FL |EVENT TIME: [EST]|
|LICENSE#: 2333-1 AGREEMENT: Y |LAST UPDATE DATE: 03/29/1999|
| DOCKET: |+----------------------------+
| |PERSON ORGANIZATION |
| |MARK LESSER R2 |
| |FRED COMBS NMSS |
+------------------------------------------------+ |
| NRC NOTIFIED BY: CHARLES ADAMS | |
| HQ OPS OFFICER: JOHN MacKINNON | |
+------------------------------------------------+ |
|EMERGENCY CLASS: N/A | |
|10 CFR SECTION: | |
|NAGR AGREEMENT STATE | |
| | |
| | |
| | |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| - AGREEMENT STATE REPORT - TROXLER MOISTURE DENSITY GAUGE RUN OVER - |
| |
| While taking a measurement, a Troxler #3440 gauge (serial number 029358) was |
| run over by a dump truck. The handle was broken off, and the source could |
| not be retracted into the case. The source was extended approximately 12 |
| inches. Investigators responded and put a pig over the source and |
| transported the gauge to the state environmental lab. The gauge was placed |
| in the Radioactive Activity Material storage facility until the owner can |
| get a special shipping case from Troxler: to return the gauge for repair. |
| Any further actions are referred to Materials Licensing. The licensee is |
| the H. W. Lochner facility is located in Clearwater, Florida. |
| |
| Troxler Model #3440 contains 8 mCi of Cesium-137 and 40 mCi of |
| Americium-241/Beryllium. |
| |
| Call the NRC Operations Officer for contact numbers. |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
|General Information or Other |Event Number: 35524 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| REP ORG: COGEMA MINING, INC. |NOTIFICATION DATE: 03/29/1999|
|LICENSEE: COGEMA MINING, INC. |NOTIFICATION TIME: 16:15[EST]|
| CITY: Linch REGION: 4 |EVENT DATE: 03/26/1999|
| COUNTY: Campbell STATE: WY |EVENT TIME: 12:00[MST]|
|LICENSE#: AGREEMENT: N |LAST UPDATE DATE: 03/29/1999|
| DOCKET: |+----------------------------+
| |PERSON ORGANIZATION |
| |LINDA HOWELL R4 |
| |SCOTT MOORE NMSS |
+------------------------------------------------+JOE HOLONICH NMSS |
| NRC NOTIFIED BY: JOHN VASELIN |JOHN MORRIS DOE |
| HQ OPS OFFICER: JOHN MacKINNON |M. ROBERTSON, NRC EPA |
+------------------------------------------------+G. BICKERTON USDA |
|EMERGENCY CLASS: N/A | |
|10 CFR SECTION: | |
|NONR OTHER UNSPEC REQMNT | |
| | |
| | |
| | |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| SPILLED 60,918 GALLONS OF WATER CONTAINING 1.0 mg/l OF URANIUM ON 03/26/99 |
| AND SPILLED 23,520 GALLONS OF WATER CONTAINING LESS THAN 0.4 mg/l OF URANIUM |
| ON 03/29/99 |
| |
| This event was called in under as a 48 hour report per Cogema Mining, Inc., |
| license. |
| |
| Two spills of injection mining solution recently occurred at the Christensen |
| Mine in Campbell County Wyoming. Both spills were located in Mine Unit 3 |
| which is currently in restoration and resulted from plumbing failures. The |
| following data summarizes the spills: |
| |
| Date Location |
| Estimated Uranium |
| Gallons mg/l |
| |
| 03/26/99 Well H17-1 60,918 |
| 1.0 |
| |
| 03/29/99 Module bldg 3-1 23,520 |
| <0.4 |
| |
| For purposes of reporting spills, the NRC license considers any spill of |
| 10,000 gallons of more to be significant from an operations standpoint, |
| regardless of the chemical and radioactive characteristics of the spill. |
| Therefore, both spills are reported. |
| |
| Health and Environmental Hazards: None expected. The solution does not |
| pose a health or environmental hazard and did not leave the NRC permitted |
| area. Note that the nearest community is Linch, Wyoming, approximately 15 |
| miles to the southwest. |
| |
| Corrective Actions: Well H17-1: Well was shut down until the plumbing |
| failure can be repaired. |
| Available spill solution is being recovered. |
| |
| Module building 3-1: The plumbing failure was repaired and flow is back on |
| line. |
| |
| Soil samples have been collected at both spill locations and will be |
| analyzed for Ra-226 to determine if soil clean-up is needed. |
| |
| Written Notification: A written notification giving further details will be |
| submitted to the NRC Uranium Recovery Branch Chief within 7 days. |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
|Power Reactor |Event Number: 35525 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: BEAVER VALLEY REGION: 1 |NOTIFICATION DATE: 03/29/1999|
| UNIT: [] [2] [] STATE: PA |NOTIFICATION TIME: 20:22[EST]|
| RXTYPE: [1] W-3-LP,[2] W-3-LP |EVENT DATE: 03/29/1999|
+------------------------------------------------+EVENT TIME: 18:01[EST]|
| NRC NOTIFIED BY: TOM COTTER |LAST UPDATE DATE: 03/29/1999|
| HQ OPS OFFICER: JOHN MacKINNON +-----------------------------+
+------------------------------------------------+PERSON ORGANIZATION |
|EMERGENCY CLASS: N/A |KATHLEEN MODES R1 |
|10 CFR SECTION: |STUART RICHARDS NRR |
|AESF 50.72(b)(2)(ii) ESF ACTUATION |FRANK CONGEL IRO |
| | |
| | |
| | |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE |
+-----+----------+-------+--------+-----------------+--------+-----------------+
| | |
|2 N N 0 Cold Shutdown |0 Cold Shutdown |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| PARTIAL LOSS OF POWER DUE TO 4.10KV BUS UNIT STATION SERVICE TRANSFORMER |
| SUPPLY OVERCURRENT TRIP. EMERGENCY DIESEL GENERATOR 2-1 SUPPLYING POWER TO |
| VITAL BUS "AE". |
| |
| At 1801 hours, "4160V Bus Unit Station Service Transformer Supply |
| Overcurrent Trip" alarm was received. This alarm indicates that the supply |
| breaker, 42C, to the normal 4kV bus "2A" opened and deenergized the bus. The |
| "2A" bus supplies train "A" emergency 4kV bus "AE" so it also deenergized. |
| The emergency diesel generator 2-1 started and reenergized the "AE" |
| emergency bus. The "B" train of electrical power and safeguards equipment |
| remained fully operable, the emergency diesel generator is fully operable if |
| needed. Prior to the overcurrent trip, the plant was in mode 5 (cold |
| shutdown) with Reactor Coolant System temperature at 97�F and 280 psig. |
| Their was no interruption to core cooling during the event. Core cooling |
| was being provided by the "B" train of the residual heat removal system and |
| was unaffected. Both trains of residual heat removal remain operable. The |
| site maintenance department is evaluating the cause for the relay protection |
| actuation. The 2-1 emergency diesel generator will continue to supply the |
| emergency bus until this investigation is completed and normal power is |
| restored. The vital buses cannot be cross connected and emergency diesel |
| generator 2-1 has plenty of fuel to keep it operating. Spent fuel pool |
| cooling was not lost. |
| |
| Offsite power is stable, and the other emergency bus "2DF" can supply enough |
| electrical power to safe plant operation while shutdown if electrical power |
| is lost from emergency bus "2AE". |
| |
| The NRC Resident Inspector was notified of this event by the licensee. |
+------------------------------------------------------------------------------+
Page Last Reviewed/Updated Thursday, March 25, 2021
Page Last Reviewed/Updated Thursday, March 25, 2021