Event Notification Report for March 15, 2001
U.S. Nuclear Regulatory Commission
Operations Center
Event Reports For
03/14/2001 - 03/15/2001
** EVENT NUMBERS **
37831 37835 37836 37837 37838 37839 37840 37841
+------------------------------------------------------------------------------+
|Fuel Cycle Facility |Event Number: 37831 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: PORTSMOUTH GASEOUS DIFFUSION PLANT |NOTIFICATION DATE: 03/13/2001|
| RXTYPE: URANIUM ENRICHMENT FACILITY |NOTIFICATION TIME: 08:24[EST]|
| COMMENTS: 2 DEMOCRACY CENTER |EVENT DATE: 03/12/2001|
| 6903 ROCKLEDGE DRIVE |EVENT TIME: 17:45[EST]|
| BETHESDA, MD 20817 (301)564-3200 |LAST UPDATE DATE: 03/14/2001|
| CITY: PIKETON REGION: 3 +-----------------------------+
| COUNTY: PIKE STATE: OH |PERSON ORGANIZATION |
|LICENSE#: GDP-2 AGREEMENT: N |GEOFFREY WRIGHT R3 |
| DOCKET: 0707002 |JOHN HICKEY NMSS |
+------------------------------------------------+ |
| NRC NOTIFIED BY: JOE HALCOMB | |
| HQ OPS OFFICER: FANGIE JONES | |
+------------------------------------------------+ |
|EMERGENCY CLASS: N/A | |
|10 CFR SECTION: | |
|NBNL RESPONSE-BULLETIN | |
| | |
| | |
| | |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| NRC BULLETIN 91-01 - 24 HOUR REPORT |
| |
| The following is taken from the faxed report: |
| |
| ON 3/12/01 AT 1745 HOURS X-705 OPERATIONS PERSONNEL WERE CONDUCTING ROUTINE |
| INSPECTIONS OF THE TUNNEL BASEMENT AREA WHEN THEY IDENTIFIED THAT THE |
| SCAVENGER SYSTEM WOULD NOT OPERATE IN THE 'AUTOMATIC' OR THE 'MANUAL' MODE. |
| NCSA-0705_035.A05 REQUIREMENT 5d STATES "THE SCAVENGER PUMP SWITCH VERIFIED |
| NOT TO BE IN THE 'MANUAL' MODE WHILE UNATTENDED." THE STATUS OF THE |
| SCAVENGER PUMP SWITCH WAS IN 'AUTOMATIC' MODE BUT IT WAS IDENTIFIED WHEN |
| TESTED THAT THE PUMP WOULD NOT OPERATE IN THE 'AUTOMATIC' OR THE 'MANUAL' |
| MODE BUT WOULD OPERATE IN THE 'MANUAL BY-PASS' MODE. THIS VIOLATES THE |
| INTENT OF THE NCSA REQUIREMENT WHEREBY THE PUMP WOULD NOT START |
| AUTOMATICALLY NOR WAS THE PUMP MANNED IN THE 'MANUAL' MODE. THE FACT THAT |
| A TIME FRAME EXISTED WHEN THE PUMP WOULD NOT START IN THE 'AUTOMATIC' MODE |
| AND DURING THIS SAME TIME FRAME THE PUMP WAS NOT MANNED IN THE 'MANUAL' |
| MODE CONSTITUTES A LOSS OF ONE CONTROL WHICH IS RELIED ON TO MEET THE DOUBLE |
| CONTINGENCY PRINCIPAL, |
| |
| SAFETY SIGNIFICANCE OF EVENTS: |
| |
| LOW = The failure of the Scavenger Pump to operate In the automatic mode |
| represents the loss of one control (5d) relied upon for double contingency. |
| The failure of the Scavenger Pump to operate in the automatic mode would |
| allow the Scavenger System Storage Tank to overflow and solution to collect |
| on the floor of the basement The size of the floor area and the remaining |
| control on the amount of solution transferred make a criticality nearly |
| non-credible. |
| |
| POTENTIAL CRITICALITY PATHWAYS INVOLVED (BRIEF SCENARIO(S) OF HOW |
| CRITICALITY COULD OCCUR): |
| |
| Six of eight Fissile Solution Storage Banks fail in such a way that all of |
| the Fissile Solution collects in the tunnel basement floor. This is |
| sufficient Fissile Solution to exceed the safe depth of 1.5 inches for |
| solutions containing greater than 100 wt.% U-235. |
| |
| CONTROLLED PARAMETERS (MASS, MODERATION, GEOMETRY, CONCENTRATION, ETC.): |
| |
| Volume Control was lost when the Scavenger Pump failed. Geometry Control was |
| maintained throughout this event. |
| |
| ESTIMATED AMOUNT, ENRICHMENT, FORM OF LICENSED MATERIAL (INCLUDE PROCESS |
| LIMIT AND % WORST CASE OP CRITICAL MASS): |
| |
| The Tunnel Storage System receives Fissile Solution for various operations |
| in the X-705 Facility. The most likely form is UO2F2 in solution with a |
| maximum enrichment of 100 wt.% U-235. |
| |
| NUCLEAR CRITICALITY SAFETY CONTROL(S) OR CONTROL SYSTEM(S) AND DESCRIPTION |
| OF THE FAILURES OR DEFICIENCIES: |
| |
| Automatic Mode of Scavenger Pump failed. Pump not manned in Manual Mode, 5d |
| Control lost. Note: Pump would operate in the Manual By-Pass Mode but the |
| pump was unmanned. Since no Fissile Solution leaked and allowed >1.5 inches |
| of solution to collect on the floor the second control was maintained. |
| |
| CORRECTIVE ACTIONS TO RESTORE SAFETY SYSTEM AND WHEN EACH WAS IMPLEMENTED: |
| |
| Entered Anomalous Condition. Assigned Operator to man the system until |
| facility status was verified. Immediately verified no evolutions in progress |
| that could challenge the Scavenger System. Tagged out the power supplies to |
| all facility equipment that could challenge the Scavenger System. Emergent |
| Work authorized by Plant Shift Superintendent for repairs to Scavenger |
| System. Called in off-duty Nuclear Criticality Safety Staff to assess |
| compliance, create Anomalous Condition Report and oversee the efforts to |
| establish the lost control. Control established at 2038 hours by manning the |
| pump controls. |
| |
| The licensee notified the NRC Resident Inspector as well as the DOE |
| representative. |
| |
| * * * UPDATE 1808EST ON 3/14/01 FROM JOE HALCOMB TO S. SANDIN * * * |
| |
| The following update was submitted to clarify the above report: |
| |
| "03/14/01 - Update #1 - The Nuclear Criticality Safety (NCS) Group performed |
| a follow up assessment of the above event. A revision to the NCS Anomalous |
| Condition Report was issued and it determined that the malfunction of the |
| scavenger system did not constitute a loss of an NCS control and that double |
| contingency was maintained. The previous issue would not have been reported |
| based on the revised NCS Anomalous Condition Report." |
| |
| The licensee informed the NRC resident inspector and DOE site |
| representative. Notified R3DO(Wright) and NMSS(Hickey). |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
|General Information or Other |Event Number: 37835 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| REP ORG: SAINT VINCENT MEDICAL CENTER |NOTIFICATION DATE: 03/14/2001|
|LICENSEE: BEST INDUSTRIES |NOTIFICATION TIME: 09:17[EST]|
| CITY: BRIDGEPORT REGION: 1 |EVENT DATE: 03/12/2001|
| COUNTY: STATE: CT |EVENT TIME: 17:00[EST]|
|LICENSE#: AGREEMENT: N |LAST UPDATE DATE: 03/14/2001|
| DOCKET: |+----------------------------+
| |PERSON ORGANIZATION |
| |PETE ESELGROTH R1 |
| |KEVIN RAMSEY NMSS |
+------------------------------------------------+ |
| NRC NOTIFIED BY: J. MELI | |
| HQ OPS OFFICER: JOHN MacKINNON | |
+------------------------------------------------+ |
|EMERGENCY CLASS: N/A | |
|10 CFR SECTION: | |
|CCCC 21.21 UNSPECIFIED PARAGRAPH | |
| | |
| | |
| | |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| DEFECTIVE IODINE-125 SEEDS. |
| |
| One hundred thirty-three (133) I-125 sources each with an activity of |
| approximately 0.3 millicuries were received by the Saint Vincent Medical |
| Center located in Bridgeport, CT. The I-125 seeds are used for prostate |
| implants. Upon receiving the sources they were counted and the seeds' |
| activity was checked. They were then placed in a sterilization tray which |
| has 10 wells (the seeds were distributed among the 10 wells). The tray |
| has a cover which allows for steam circulation. The same day or the |
| following morning the trays were sent forth to be sterilized. After |
| sterilization the seeds are taken out of the sterilizer and the sterilizer |
| surveyed. Nothing detectable was noted. Later that day the seeds were |
| removed from the wells and loaded into needles. At the conclusion of this |
| process the licensee did a survey of the area. It was then when the |
| licensee found a rather high level of radiation, not high enough to be a |
| seed. After further investigation the licensee concluded that the |
| sterilization tray was contaminated and highly contaminated in the area of |
| at least 5 of the 10 wells. The licensee's assumption is that one or more |
| the seeds opened up during sterilization. The seeds were fine prior to |
| sterilization. Total estimated removable contamination found on the tray |
| was 4 microcuries. A more through survey was performed on everything that |
| had came in contact with the tray. It was found that the inner wrapping |
| that goes around the tray before it is placed in the sterilizer was |
| contaminated. Nothing else that had come in contact with the tray was |
| found to be contaminated. Personnel do not seem to be contaminated. The two |
| people who were involved in the loading process are scheduled to have |
| thyroid uptake exams today. This incident was reported to the seed |
| manufacturer, Best Industries, and the seeds will be shipped back to them. |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
|Power Reactor |Event Number: 37836 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: SEABROOK REGION: 1 |NOTIFICATION DATE: 03/14/2001|
| UNIT: [1] [] [] STATE: NH |NOTIFICATION TIME: 13:11[EST]|
| RXTYPE: [1] W-4-LP |EVENT DATE: 03/14/2001|
+------------------------------------------------+EVENT TIME: 10:30[EST]|
| NRC NOTIFIED BY: HUGH HAWKINS |LAST UPDATE DATE: 03/14/2001|
| HQ OPS OFFICER: STEVE SANDIN +-----------------------------+
+------------------------------------------------+PERSON ORGANIZATION |
|EMERGENCY CLASS: N/A |PETE ESELGROTH R1 |
|10 CFR SECTION: | |
|*PRE 50.72(b)(2)(xi) OFFSITE NOTIFICATION | |
| | |
| | |
| | |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|1 N N 0 Hot Standby |0 Hot Standby |
| | |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| OFFSITE NOTIFICATION TO VARIOUS AGENCIES CONCERNING AN OIL SPILL ONSITE |
| |
| "At 10:30 AM on 3/14/2001 the following agencies were notified of an oil |
| leak on site. |
| |
| New Hampshire DES |
| National Response Center |
| US Coast Guard |
| Environmental Protection Agency (EPA) |
| |
| "About 1 gallon of oil was observed on top of a concrete pad near the |
| vehicle maintenance shop. The oil came through the pad via cracks in the |
| concrete. There is an oil line that runs under this pad from a 6000 gallon |
| above ground tank. The tank has been isolated, local storm drains have been |
| protected and a contractor is on site to excavate the area and determine the |
| extent of the problem. The notifications were made as a precautionary |
| measure since the quantity of oil under the concrete pad is unknown. The |
| oil was first observed on 3/13/01 at approximately 1600." |
| |
| The licensee informed the NRC resident inspector. |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
|Hospital |Event Number: 37837 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| REP ORG: CHRISTIANA CARE HEALTH SERVICE |NOTIFICATION DATE: 03/14/2001|
|LICENSEE: CHRISTIANA CARE HEALTH SERVICE |NOTIFICATION TIME: 13:15[EST]|
| CITY: WILMINGTON REGION: 1 |EVENT DATE: 03/14/2001|
| COUNTY: STATE: DE |EVENT TIME: 07:10[EST]|
|LICENSE#: 07-12153-02 AGREEMENT: N |LAST UPDATE DATE: 03/14/2001|
| DOCKET: |+----------------------------+
| |PERSON ORGANIZATION |
| |PETE ESELGROTH R1 |
| |FRITZ STURZ NMSS |
+------------------------------------------------+ |
| NRC NOTIFIED BY: EDWARD TORVIK | |
| HQ OPS OFFICER: STEVE SANDIN | |
+------------------------------------------------+ |
|EMERGENCY CLASS: N/A | |
|10 CFR SECTION: | |
|BAE1 20.2202(b)(1) PERS OVEREXPOSURE | |
| | |
| | |
| | |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| 24-HOUR REPORT INVOLVING POTENTIAL PERSONNEL OVEREXPOSURE |
| |
| At approximately 0710EST a technician at the Christiana Care Health Services |
| spilled a tube in the corner of the hot lab containing between 30-50 ml of |
| Technetium-99m milked from the generator. The activity was measured as 650 |
| millicuries immediately prior to the spill. The hot lab was promptly |
| evacuated. There was no personnel contamination involved. Initial rad |
| surveys of the affected area showed between 80 and 200 mr/hr prior to |
| decontamination. Following final decontamination measured rad levels taken |
| at 1000EST were approximately 10 to 40 mr/hr. Access to the lab has been |
| restored, however, the corner area is taped off and covered by plastic to |
| minimize the spread of contamination and allow for decay. |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
|Power Reactor |Event Number: 37838 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: HATCH REGION: 2 |NOTIFICATION DATE: 03/14/2001|
| UNIT: [1] [] [] STATE: GA |NOTIFICATION TIME: 16:37[EST]|
| RXTYPE: [1] GE-4,[2] GE-4 |EVENT DATE: 03/09/2001|
+------------------------------------------------+EVENT TIME: 06:45[EST]|
| NRC NOTIFIED BY: HARRY RUSSELL |LAST UPDATE DATE: 03/14/2001|
| HQ OPS OFFICER: STEVE SANDIN +-----------------------------+
+------------------------------------------------+PERSON ORGANIZATION |
|EMERGENCY CLASS: N/A |ROBERT HAAG R2 |
|10 CFR SECTION: | |
|*IND 50.72(b)(3)(v)(D) ACCIDENT MITIGATION | |
| | |
| | |
| | |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|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
+------------------------------------------------------------------------------+
| HIGH PRESSURE COOLING INJECTION (HPCI) RENDERED INOPERABLE DUE TO FAULTY |
| BATTERY CHARGER |
| |
| "Investigation of the failure of battery charger 1R42-S031 on 3/9/2001 |
| (reference Condition Report 2001001827) has determined that the Unit 1 HPCI |
| system was inoperable from the time of receipt of the first 'HPCI System |
| Inverter Circuit Failure' annunciator until the time charger 1R42-S031 was |
| removed from service. During this time (approximately 15 to 20 minutes), the |
| HPCI system inverter was tripping on high voltage and resetting |
| automatically when voltage levels returned to normal. The voltage |
| fluctuations causing the inverter to trip and reset were caused by an |
| internal fault in charger 1R42-S031: a bad fuse was making intermittent |
| connection resulting in intermittent firing of the charger's |
| silicon-controlled rectifiers (SCRs) and rapidly changing current and |
| voltage outputs. These fluctuations and the random tripping of the HPCI |
| system inverter rendered the HPCI system unreliable, and hence inoperable, |
| until the cause of the fluctuations was corrected, that is, until the |
| charger was removed from service. Determined to be reportable 3-14-2001 @ |
| 1338 EST." |
| |
| The licensee informed the NRC resident inspector. |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
|Power Reactor |Event Number: 37839 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: SUSQUEHANNA REGION: 1 |NOTIFICATION DATE: 03/14/2001|
| UNIT: [] [2] [] STATE: PA |NOTIFICATION TIME: 18:02[EST]|
| RXTYPE: [1] GE-4,[2] GE-4 |EVENT DATE: 03/14/2001|
+------------------------------------------------+EVENT TIME: 15:08[EST]|
| NRC NOTIFIED BY: ROBERT R. BOESCH |LAST UPDATE DATE: 03/14/2001|
| HQ OPS OFFICER: STEVE SANDIN +-----------------------------+
+------------------------------------------------+PERSON ORGANIZATION |
|EMERGENCY CLASS: |PETE ESELGROTH R1 |
|10 CFR SECTION: | |
|*ESF 50.72(b)(3)(iv)(A) VALID SPECIF SYS ACTUAT| |
|*INB 50.72(b)(3)(v)(B) POT RHR INOP | |
| | |
| | |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE |
+-----+----------+-------+--------+-----------------+--------+-----------------+
| | |
|2 N N 0 Refueling |0 Refueling |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| UNIT 2 EXPERIENCED AN UNEXPECTED LOSS OF SHUTDOWN COOLING DUE TO TRIPPING OF |
| VARIOUS POWER SUPPLY BREAKERS |
| |
| "Unit 2 was in Mode 5 on the fifth day of its 10th Refuel and Inspection |
| Outage. At 1508 hours, the unit experienced an unexpected loss of Division 1 |
| RPS Power supply. The loss of power was a result of the Electrical |
| Protection Assembly (EPA) A & C breakers and motor generator output breaker |
| tripping. The cause is under investigation. |
| |
| "The loss of power caused the RHR Shutdown Cooling suction valve HV251F009 |
| to close. This is a common suction valve to both divisions of RHR and |
| resulted in the complete loss of RHR Shutdown Cooling. The reactor currently |
| has its head removed with the reactor cavity flooded up with the gates to |
| the spent fuel pool removed. A Supplemental Decay Heat Removal system was in |
| service at the time, but was not considered fully capable of decay heat |
| removal. Reactor coolant temperature increased less than 2 degrees during |
| the 37 minutes SDC was out of service. The RPS power supply was switched to |
| its alternate supply and SDC was restored at 1545 hours. In accordance with |
| 10CFR50.72(b)(3)(v) this represents a loss of a safety system which removes |
| residual heat and requires an 8 hour ENS call. In addition to the isolation |
| of RHR SDC, RWCU isolated due to containment valve HV244F001 closing, and |
| Unit 2 HVAC Zone 3 (refuel floor) isolated. These isolations constitute an |
| actuation of a Containment Isolation signal that affected multiple systems, |
| and is reportable per |
| 10CFR50.72(b)(3)(iv)(A)." |
| |
| Peak temperature after losing SDC was 105 degrees. The licensee informed the |
| NRC resident inspector. |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
|Power Reactor |Event Number: 37840 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: PEACH BOTTOM REGION: 1 |NOTIFICATION DATE: 03/14/2001|
| UNIT: [2] [] [] STATE: PA |NOTIFICATION TIME: 20:13[EST]|
| RXTYPE: [2] GE-4,[3] GE-4 |EVENT DATE: 03/14/2001|
+------------------------------------------------+EVENT TIME: 14:10[EST]|
| NRC NOTIFIED BY: ROSS MOONITZ |LAST UPDATE DATE: 03/14/2001|
| HQ OPS OFFICER: STEVE SANDIN +-----------------------------+
+------------------------------------------------+PERSON ORGANIZATION |
|EMERGENCY CLASS: N/A |PETE ESELGROTH R1 |
|10 CFR SECTION: | |
|*IND 50.72(b)(3)(v)(D) ACCIDENT MITIGATION | |
| | |
| | |
| | |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|UNIT |SCRAM CODE|RX CRIT|INIT PWR| INIT RX MODE |CURR PWR| CURR RX MODE |
+-----+----------+-------+--------+-----------------+--------+-----------------+
|2 N Y 100 Power Operation |100 Power Operation |
| | |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| HPCI DECLARED INOPERABLE DUE TO FAILURE OF EXHAUST LINE VACUUM RELIEF VALVES |
| TO FUNCTION DURING IST TESTING |
| |
| "During routine testing of the Unit 2 High Pressure Coolant Injection system |
| (HPCI) exhaust line vacuum relief valves (VRV), it was discovered that both |
| VRVs failed to open at their In Service Test (IST) required differential |
| pressure value. The Unit 2 HPCI system has been declared inoperable and |
| repairs are in progress. |
| |
| "This event is being reported in accordance with 10CFR50.72(b)(3)(v)(D) due |
| to a failure of a single train system which prevents fulfillment of a safety |
| function." |
| |
| With HPCI inoperable this places Unit 2 in a 14-day Limiting Condition of |
| Operation. All other ECCS systems have been verified operable. |
| |
| The licensee informed the NRC resident inspector. |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
|Power Reactor |Event Number: 37841 |
+------------------------------------------------------------------------------+
+------------------------------------------------------------------------------+
| FACILITY: SAINT LUCIE REGION: 2 |NOTIFICATION DATE: 03/14/2001|
| UNIT: [] [2] [] STATE: FL |NOTIFICATION TIME: 20:20[EST]|
| RXTYPE: [1] CE,[2] CE |EVENT DATE: 03/14/2001|
+------------------------------------------------+EVENT TIME: 17:52[EST]|
| NRC NOTIFIED BY: DAVE WILLIAMS |LAST UPDATE DATE: 03/14/2001|
| HQ OPS OFFICER: STEVE SANDIN +-----------------------------+
+------------------------------------------------+PERSON ORGANIZATION |
|EMERGENCY CLASS: N/A |ROBERT HAAG R2 |
|10 CFR SECTION: | |
|*RPS 50.72(b)(2)(iv)(B) RPS ACTUATION - CRITICA| |
|*ESF 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 |
+-----+----------+-------+--------+-----------------+--------+-----------------+
| | |
|2 A/R Y 100 Power Operation |0 Hot Standby |
| | |
+------------------------------------------------------------------------------+
EVENT TEXT
+------------------------------------------------------------------------------+
| UNIT 2 EXPERIENCED A TURBINE TRIP - REACTOR TRIP ON LOSS OF LOAD |
| |
| "At 1752 hours on 3/14/01, the St. Lucie Unit 2 reactor automatically |
| tripped on a turbine loss of load signal. Prior to the trip, the output |
| breaker on the 2A Control Element Drive motor generator set opened for an |
| unknown reason. Shortly thereafter, various Control Rod trouble alarms |
| annunciated and the Control Rods dropped into the core due to loss of power |
| on the Control Rod busses. The loss of power to the Control Rod busses |
| initiated a turbine trip, which in turn generated a Reactor Protective |
| System trip signal on loss of load. All Control Rods inserted fully. |
| Standard Post Trip actions were completed satisfactorily with all safety |
| functions met. |
| |
| "Following the trip, it was noticed that the 2A1 non-safety related 6.9KV |
| electric busses did not automatically transfer to the Startup Transformers. |
| This resulted in the loss of power to the 2A1 and 2B2 Reactor Coolant Pumps |
| and the 2A Main Feedwater pump. The cause for the failure to transfer is |
| being investigated. Due to the loss of the Reactor Coolant Pumps, the |
| Reactor Coolant System was manually depressurized to 1850 psia per plant |
| procedures. |
| |
| "The Auxiliary Feedwater Actuation System automatically actuated on low |
| Steam Generator level as expected for reactor trips from high power level. |
| Steam Generator level is currently being maintained by the 2B Main Feedwater |
| pump. |
| |
| "The reactor is currently stable in Mode 3 and the cause of the trip is |
| under investigation." |
| |
| No primary safety or reliefs lifted during the transient. Decay heat is |
| being removed via the bypass valves to the main condenser. The AFW pumps |
| are operating but not supplying feed to the Steam Generators. The licensee |
| had not verified whether any atmospheric dumps cycled. There is no known |
| Steam Generator tube leakage at this time. Normal offsite power remains |
| available and there was no impact on Unit 1 which is operating at 100% |
| power. Unit 2 will remain in Hot Standby pending development and completion |
| of corrective actions. The licensee informed the NRC resident inspector. |
+------------------------------------------------------------------------------+
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Page Last Reviewed/Updated Thursday, March 25, 2021