| U.S. Nuclear Regulatory Commission
Operations Center Event Reports For
08/05/2011 - 08/08/2011 ** EVENT NUMBERS ** |
 | Part 21 | Event Number: 47063 | Rep Org: QUALTECH NP
Licensee: QUALTECH NP
Region: 3
City: CINCINNATI State: OH
County:
License #:
Agreement: Y
Docket:
NRC Notified By: KURT MITCHELL
HQ OPS Officer: DONALD NORWOOD | Notification Date: 07/15/2011
Notification Time: 20:43 [ET]
Event Date: 07/15/2011
Event Time: [EDT]
Last Update Date: 08/05/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
21.21 - UNSPECIFIED PARAGRAPH
| Person (Organization):
TAMARA BLOOMER (R3DO)
SCOTT FREEMAN (R2DO)
PART 21 GRP by EMAIL ()
| Event Text POTENTIAL DEFECT IN QUALTECH NP SAFETY RELATED MOTOR CONTROL CENTER BUCKETS
The following information was received via facsimile from QualTech NP:
"This letter is issued to provide initial notification of a potential defect in QualTech NP safety related MCC [Motor Control Center] buckets, which were commercial grade dedicated at our Cincinnati facility. On June 9, 2011, TVA Watts Bar Unit 2 notified QualTech NP of a failure on a transformer module associated with an indicator light on the MCC bucket. Based on our investigations, QualTech NP has identified quality and performance issues relating to the 480 VAC input (primary side) portion of the subject indicating light. The light in question has shown the potential to flash/arc internally on the primary winding side of the built in transformer and create a substantial fault current. This fault current not only disables the light but can be large enough to trip the upstream circuit breaker, thus disabling all associated safety related circuitry.
"The issues appear to revolve around inconsistent and poor quality fabrication methods employed during manufacturing, primarily with how the wires were wrapped in critical areas of the primary and how they were routed and attached to the termination points.
"The recommended corrective action for existing safety related MCC buckets is to replace the indicator light and transformer module with a newly qualified acceptable substitute. The new indicator light and transformer module will go through a series of dedication inspections and tests to ensure that a similar failure does not occur.
"Based on review of our records, Tennessee Valley Authority is the only customer to have these defective modules."
* * * UPDATE ON 8/05/11 AT 1131 EDT TO HUFFMAN VIA FAX FROM QUALTECH NP * * *
"QualTech NP conducted failure analyses to determine the root cause. Based on the results of our investigations, QualTech NP has determined that this failure represents a defect in a basic component as defined by 10CFR21.
"The failure analyses concluded that all of the failure modes encountered were due to manufacturing defects associated with the soldering and handling of the wire strands in the vicinity of the line terminals.
"QualTech NP has established a corrective action plan to replace all of these components known to be installed in safety-related applications. We are currently in the process of evaluating a suitable replacement.
"Based on review of our records, Tennessee Valley Authority is the only customer to have these defective modules. We have been in close communications with TVA on this issue.
"The specific component is Model Number 9001KP5R31, manufactured by Square D."
R2DO (Desai) and the Part 21 Group notified. |
| !!!!! THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED !!!!! | | Agreement State | Event Number: 47115 | Rep Org: NC DIV OF RADIATION PROTECTION
Licensee: NC RADIATION THERAPY SERVICES INC
Region: 1
City: ASHEVILLE State: NC
County:
License #: 011-1276-1
Agreement: Y
Docket:
NRC Notified By: CLIFF HARRIS
HQ OPS Officer: JOE O'HARA | Notification Date: 08/02/2011
Notification Time: 10:54 [ET]
Event Date: 07/28/2011
Event Time: 12:00 [EDT]
Last Update Date: 08/03/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
AGREEMENT STATE
| Person (Organization):
RONALD BELLAMY (R1DO)
ANGELA MCINTOSH (FSME)
| Event Text FIRE AT RADIATION THERAPY PRACTICE
The following was received from the state via e-mail:
"N.C. Radiation Protection Section was notified on 1 August 2011 by the Regional Medical Physicist for NC Radiation Therapy Management Services, Inc. d/b/a 21st Century Oncology of a major fire on the fifth floor of the building in which the licensee operates a radiation therapy practice on the ground floor. The ground floor did not receive direct fire/smoke damage, but did realize significant water damage to portions of its facility. One fireman was killed and 10 injured while fighting the fire. The entire building has been closed and is currently under the command of the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) National Response Team (NRT) along with special agents from their Charlotte Field Division. Other agencies involved in this investigation are the North Carolina State Bureau of Investigation and the Asheville Fire Department. The licensee has been permitted to enter its facility once to retrieve critical computer servers that are utilized in patient care at their clinics throughout western North Carolina. The licensee examined its HDR remote afterloader containing one Ir-192 sealed source (<12 Ci) and found the afterloader to be undamaged and securely locked in a treatment vault. The licensee also has a small number of Cs-137 brachytherapy sealed sources (<450 mCi total) in a locked lead source safe within a locked source storage room. The licensee determined that there was no damage to the source storage room and that the room is secure. The licensee is in the process of contracting Nucletron to remove and dispose of the Ir-192 sealed source and is investigating the disposal of all Cs-137 brachytherapy sealed sources.
"The Radiation Protection Section has assigned an inspector to contact the ATF to determine the earliest possible time for a site visit.
"N.C. Radiation Protection has not received any media attention as of this report. No press release has been issued."
NC Event Report ID No. NC-11-42
* * * UPDATED AT 1515 EDT ON 08/03/11 FROM CLIFF HARRIS TO S. SANDIN * * *
The State of North Carolina is retracting this report based upon further review and discussions with NRC Region I Office staff in that the sealed sources were not impacted by the fire.
Notified R1DO (Bellamy) and FSME (McIntosh). |
| Agreement State | Event Number: 47117 | Rep Org: ALABAMA RADIATION CONTROL
Licensee: QUANTEGY, INC.
Region: 1
City: OPELIKA State: AL
County:
License #:
Agreement: Y
Docket:
NRC Notified By: DAVID A. TURBERVILLE
HQ OPS Officer: STEVE SANDIN | Notification Date: 08/02/2011
Notification Time: 16:43 [ET]
Event Date: 07/20/2011
Event Time: [CDT]
Last Update Date: 08/02/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
AGREEMENT STATE
| Person (Organization):
RONALD BELLAMY (R1DO)
CHRISTEPHER MCKENNEY (FSME)
ILTAB VIA E-MAIL ()
|
| This material event contains a "Less than Cat 3" level of radioactive material. | Event Text AGREEMENT STATE REPORT OF LOST GENERAL LICENSED DEVICES
The following report was received from the State of Alabama via fax:
"On the afternoon of July 20, 2011, a representative of the Alabama Office of Radiation Control [the Agency] discovered that five general license devices containing radioactive material were unaccounted for at the closed Quantegy, Inc. facility located in Opelika, AL. The Agency representative was there to perform a routine inspection of general licensed activities and discovered that the facility was being demolished and the metal was being sold for scrap. Records indicate that the company did possess at one time fifteen general license devices. The Agency representative was able to account for ten of the fifteen devices. Five devices are unaccounted for at this time. The demolition crew, the scrap company and the Georgia Department of Natural Resources have been made aware of the missing devices. Also, the Agency is working with the manufacturer to determine if these devices were returned to the manufacturer in the past. The devices missing include four NDC Model 105 devices containing 250 millicuries (original assay) each of Cm-244. The serial numbers on record for these devices are 6075, 6025, 6102 and 6024. The fifth device missing is an NDC Model 103 device containing 150 millicuries (original assay) of Am-241. The serial number on record for this device is 2063.
"This is all the information that this Agency has at this time and is current as of 1530 CDT, August 2, 2011."
Alabama Incident No.: 11-30
THIS MATERIAL EVENT CONTAINS A "LESS THAN CAT 3" LEVEL OF RADIOACTIVE MATERIAL
Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf
This source is not amongst those sources or devices identified by the IAEA Code of Conduct for the Safety & Security of Radioactive Sources to be of concern from a radiological standpoint. Therefore is it being categorized as a less than Category 3 source. |
| Power Reactor | Event Number: 47126 | Facility: MONTICELLO
Region: 3 State: MN
Unit: [1] [ ] [ ]
RX Type: [1] GE-3
NRC Notified By: RON UGLOW
HQ OPS Officer: CHARLES TEAL | Notification Date: 08/05/2011
Notification Time: 16:53 [ET]
Event Date: 08/05/2011
Event Time: 08:54 [CDT]
Last Update Date: 08/05/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
26.719 - FITNESS FOR DUTY
| Person (Organization):
RICHARD SKOKOWSKI (R3DO)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 1 | N | Y | 100 | Power Operation | 100 | Power Operation | Event Text 24-HOUR FITNESS-FOR-DUTY REPORT
A non-licensed contract supervisor had a confirmed positive for alcohol during a random fitness-for-duty test. The employee's access to the plant has been terminated. Contact the Headquarters Operations Officer for additional details.
The NRC Resident Inspector has been informed. |
| Power Reactor | Event Number: 47127 | Facility: NINE MILE POINT
Region: 1 State: NY
Unit: [1] [2] [ ]
RX Type: [1] GE-2,[2] GE-5
NRC Notified By: GREG ELKINS
HQ OPS Officer: CHARLES TEAL | Notification Date: 08/05/2011
Notification Time: 21:04 [ET]
Event Date: 08/05/2011
Event Time: 19:32 [EDT]
Last Update Date: 08/05/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(xi) - OFFSITE NOTIFICATION
| Person (Organization):
RONALD BELLAMY (R1DO)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 1 | N | Y | 100 | Power Operation | 100 | Power Operation | | 2 | N | Y | 100 | Power Operation | 100 | Power Operation | Event Text OFFSITE NOTIFICATION DUE TO INADVERTENT EMERGENCY NOTIFICATION SIREN ACTUATION
"One of the 37 prompt notification sirens surrounding the James A. Fitzpatrick (JAF) and Nine Mile Point (NMP) sites spuriously activated at time 1932 EDT.
"The Oswego County 911 Center notified the NMP emergency preparedness department of the inadvertent siren activation.
"Repair technicians have deactivated and silenced the faulty siren as of time 1948 EDT.
"The cause of the inadvertent siren activation is not yet known. This issue has been entered into the site's corrective action program."
The NRC Resident Inspector has been informed. See similar EN #47128. |
| Power Reactor | Event Number: 47128 | Facility: FITZPATRICK
Region: 1 State: NY
Unit: [1] [ ] [ ]
RX Type: [1] GE-4
NRC Notified By: DAVID RICHARDSON
HQ OPS Officer: DONALD NORWOOD | Notification Date: 08/05/2011
Notification Time: 21:14 [ET]
Event Date: 08/05/2011
Event Time: 19:32 [EDT]
Last Update Date: 08/05/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(xi) - OFFSITE NOTIFICATION
| Person (Organization):
RONALD BELLAMY (R1DO)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 1 | N | Y | 100 | Power Operation | 100 | Power Operation | Event Text OFFSITE NOTIFICATION DUE TO INADVERTENT EMERGENCY NOTIFICATION SIREN ACTUATION
"The purpose of this report is to provide a telephone notification under 10CFR50.72(b)(2)(xi) to notify the NRC of the inadvertent actuation of one Oswego County Emergency notification siren at approximately 1932 EDT on 8/5/2011. Initial notification to the James A Fitzpatrick control room of the siren activation was via the RECS [Radiation Emergency Communication System] Notification System. Power was removed to the affected siren by off-site repair personnel at 1948 EDT.
"The affected siren provides coverage to Oswego County. The sirens are utility owned and shared with the Nine Mile Point site.
"In the event the sirens are needed, the county has its Hyper-Reach (911 call back system) on standby.
"This issue has been entered into the station corrective action program.
"The NRC Sr. Resident Inspector has been notified."
The licensee notified the State of New York and Oswego County. See similar EN #47127. |
| Power Reactor | Event Number: 47129 | Facility: NINE MILE POINT
Region: 1 State: NY
Unit: [ ] [2] [ ]
RX Type: [1] GE-2,[2] GE-5
NRC Notified By: GREG ELKINS
HQ OPS Officer: DAN LIVERMORE | Notification Date: 08/06/2011
Notification Time: 03:53 [ET]
Event Date: 08/06/2011
Event Time: 03:22 [EDT]
Last Update Date: 08/06/2011 | Emergency Class: UNUSUAL EVENT
10 CFR Section:
50.72(a) (1) (i) - EMERGENCY DECLARED
50.72(b)(2)(i) - PLANT S/D REQD BY TS
| Person (Organization):
RONALD BELLAMY (R1DO)
WILLIAM GOTT (IRD)
WILLIAM DEAN (R1RA)
ERIC LEEDS (NRR)
TAB BEACH (DHS)
KEVIN BISCOE (FEMA)
MIKE CHEOK (NRR)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 2 | N | Y | 85 | Power Operation | 85 | Power Operation | Event Text UNUSUAL EVENT AND PLANT SHUTDOWN DUE TO DRYWELL UNIDENTIFIED LEAKAGE GREATER THAN 10 GPM
"At 0152 [EDT], Nine Mile Point Unit 2 received red alarms for containment monitoring cabinets 10A and 10B along with a rise in drywell floor drain leakage and drywell pressure.
"At 0205 [EDT], Nine Mile Point Unit 2 entered technical specification action statement (TS 3.4.5 B) due to unidentified leakage rise of greater than 2 gpm within 24 hours.
"At 0217 EDT, the control room commenced power reduction to mitigate the rise in drywell leakage and drywell pressure.
"At 0322 EDT, Nine Mile Point Unit 2 declared an Unusual Event (EAL 2.1.1) due to unidentified drywell leakage greater than 10 gpm. Actual drywell floor drain leakage reached 11.3 gpm.
"The cause of the rise in unidentified leakage is unknown at this time.
"At 0345 EDT, Nine Mile Point Unit 2 has commenced a plant shutdown."
The licensee has notified State and local authorities. The NRC Resident Inspector has been notified.
* * * UPDATE ON 08/06/2011 AT 1140 EDT FROM JULIAN THOMPSON TO DAN LIVERMORE * * *
The licensee terminated Notice of Unusual Event at 1127 EDT because leakage rates, drywell level, drywell pressure, rad levels, and all other parameters on the licensee checklist were normal and stable.
The licensee is continuing to power down in order to perform inspections in the drywell area.
The licensee notified State and local authorities and the NRC Resident Inspector.
Notified: IRD MOC (Gott), R1RA (Dean), R1DO (Bellamy), NRR (Leeds), NRR EO (Cheok), DHS (Inzer) and FEMA (O'Connel) . |
| Power Reactor | Event Number: 47130 | Facility: BROWNS FERRY
Region: 2 State: AL
Unit: [1] [ ] [ ]
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: WILLIAM BAKER
HQ OPS Officer: RYAN ALEXANDER | Notification Date: 08/06/2011
Notification Time: 10:45 [ET]
Event Date: 08/06/2011
Event Time: 06:17 [CDT]
Last Update Date: 08/06/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(i) - PLANT S/D REQD BY TS
50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
| Person (Organization):
BINOY DESAI (R2DO)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 1 | N | Y | 98 | Power Operation | 97 | Power Operation | Event Text INITIATION OF TECHNICAL SPECIFICATION REQUIRED SHUTDOWN
"On August 6, 2011, Reactor Protection System (RPS) power supply 1B failed resulting in a partial loss of power to Primary Containment Isolation System (PCIS) groups and an invalid actuation of those PCIS groups. PCIS groups 1 and 2 received partial isolation signals with no subsequent system isolations, as designed. PCIS group 3, 6, and 8 received partial isolation signals with resulting system isolations, also as designed. The combination of loss of RPS 1B and PCIS group 6 isolation resulted in the isolation of the Drywell Floor Drain Sump and the Drywell Continuous Atmospheric Monitor for both particulate and gaseous activity. Thus, both means of automatic monitoring of Reactor Coolant System leakage became inoperable. Unit 1 entered Technical Specification Limiting Condition for Operation (LCO) 3.4.5.D (all required leakage detection systems inoperable) and immediately entered LCO 3.0.3 as required.
"At the time of occurrence, RPS 1A was being supplied from its alternate source for scheduled maintenance. Thus, the alternate source was not available to RPS 1B.
"Unit 1 entered LCO 3.0.3 at 0524 [CDT], 'Initiate actions within one hour to place the unit in MODE 2 within 10 hours; MODE 3 within 13 hours; and MODE 4 within 37 hours.' At 0617, Unit 1 began reducing reactor power to comply with LCO 3.0.3.
"This event requires a 4 hour report IAW 50.72(b)(2)(i), 'The initiation of any nuclear plant shutdown required by the plant's Technical Specifications.'
"The PCIS isolations which occurred at 0524 CDT are also reportable within 8 hours per 10CFR 50.72(b)(3)(iv)(A) 'Any event or condition that results in a valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B)(2), 'General Containment Isolation signals affecting containment isolation valves in more than one system or multiple main steam isolation valves (MSIVs)], except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation.' This event also requires an LER within 60 days per 10CFR 50.73(a)(2)(iv)(A). The event time for the PCIS isolations is 0524 CDT.
"The NRC resident inspector has been notified.
"Service Request 412927 was initiated in the Corrective Action Program."
* * * UPDATE ON 08/06/2011 AT 1350 EDT FROM WILLIAM BAKER TO ERIC SIMPSON * * *
Browns Ferry restored power to the 1B Reactor Protection System power supply at 1208 CDT, reset all isolations and exited LCO 3.0.3. The licensee plans to return the unit to full power.
The licensee notified the NRC Resident Inspector.
Notified R2DO (Binoy Desai). |
| Fuel Cycle Facility | Event Number: 47131 | Facility: LOUISIANA ENERGY SERVICES
RX Type:
Comments: URANIUM ENRICHMENT FACILITY
GAS CENTRIFUGE FACILITY
Region: 2
City: EUNICE State: NM
County: LEA
License #: SNM-2010
Agreement: Y
Docket: 70-3103
NRC Notified By: KEVIN SLAVINGS
HQ OPS Officer: KARL DIEDERICH | Notification Date: 08/06/2011
Notification Time: 13:22 [ET]
Event Date: 08/05/2011
Event Time: 16:30 [MDT]
Last Update Date: 08/06/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
PART 70 APP A (b)(1) - UNANALYZED CONDITION
| Person (Organization):
BINOY DESAI (R2DO)
BRIAN SMITH (NMSS)
| Event Text MATERIAL DISCOVERED IN AN UNANALYZED CONTAINER
"Condition Description: During the morning of 8/05/2011, Radiation Protection personnel discovered potentially contaminated waste being stored in an unmarked container in the mass spec room. Radiation Protection Management and Criticality Safety personnel were notified. Upon learning at 4:30 pm [that] the unmarked container was not a Safe By Design [SBD] container, a criticality anomalous condition was declared at approximately 4:30 pm, in accordance with CR-3-1000-04, based on a violation of Nuclear Criticality Safety (NCS) guidelines and procedural requirements. Thus, at 4:30 pm, a cognizant individual was notified of the potential safety significant condition and, therefore, understood the condition could adversely impact safety. This report is being submitted as a conservative measure as the volume of waste, mostly gloves and wipes, was much less than 12 liters and could easily fit into a SBD container. The material that could be surveyed was cleared as non-radioactive material, and placed in a clean waste container. The material that could not be surveyed was transferred to a SBD container pending further analysis. The initial analysis of the material placed in the SBD container did not indicate the presence of any trace uranic material. At no time was there ever a concern of imminent criticality or for the health and safety of workers at URENCO USA.
"(1) Radiological or chemical hazards involved, including isotopes, quantities, and chemical and physical form of any material released: Potential Uranium 235 contaminated PFPE oil ampules in a solid state.
"(2) Actual or potential health and safety consequences to the workers, the public, and the environment, including relevant chemical and radiation data for actual personnel exposures to radiation or radioactive materials or hazardous chemicals produced from licensed materials (e.g., level of radiation exposure, concentration of chemicals, and duration of exposure): None. Radiological surveys were taken on the material in the container. No radiation levels or contamination levels were noted above background. All of the material, except for 4 ampules, were released as non-radioactive. Although the ampules did not have radiation levels above background, there was a slight potential for a trace level or uranic contamination.
"(3) The sequence of occurrences leading to the Condition, including degradation or failure of structures, systems, equipment, components, and activities of personnel relied on to prevent potential accidents or mitigate their consequences: One 24 liter container was placed in the mass spec room. Instead of a 24 liter container, a 12 liter SBD container should have been utilized. Chemistry personnel used the 24 liter container to store potentially radioactive material. The actual quantity of material in the 24 liter container was less than 12 liters. Personnel should not have used the 24 liter container to store potentially radioactivity contaminated material. This was a violation of site procedure RW-1003-09, Rev. 5.
"(4) Whether the remaining structures, systems, equipment, components, and activities of personnel relied on to prevent potential accidents or mitigate their consequences are available and reliable to perform their function: The structures, systems, equipment, components, and activities of personnel relied on to prevent potential accidents or mitigate their consequences are available and reliable to perform their function.
"(5) External conditions affecting the Condition: None.
"(6) Additional actions taken by the licensee in response to the Condition: Radiation Protection Technician notified her supervisor who notified criticality safety, who then notified the shift manager. The 24 liter container was removed from the mass spec room. Radiological surveys were taken and all material released as clean except for 4 potentially contaminated ampules. Initial surveys did not find radiation levels above background on the 4 ampules. The 4 potentially contaminated ampules were placed into a 12 liter SBD container until they undergo a final analysis to determine if they contained trace uranic material or not. Actions have been initiated to establish a waste accumulation area in the mass spec room in accordance with RW-3-1000-09. Meetings have been set up with Chemistry personnel to review control of potentially contaminated material. The Criticality Safety Officer generated Condition Report 2011-2560 -- Use of non-SBD Container to collect potentially uranic contaminated waste.
"(7) Status of the condition (e.g., whether the condition is on-going or was terminated): The condition is not ongoing as the material has been placed in a SBD container.
"(8) Current and planned site status, including any declared emergency class: Plant is operational; condition is non-emergency.
"(9) Notifications, related to the condition that were made or are planned to any local, State, or other Federal agencies: None
"(10) Status of any press releases, related to the Condition that were made or are planned: None." |
| Power Reactor | Event Number: 47133 | Facility: PALO VERDE
Region: 4 State: AZ
Unit: [1] [ ] [ ]
RX Type: [1] CE,[2] CE,[3] CE
NRC Notified By: ALAN BRIESE
HQ OPS Officer: KARL DIEDERICH | Notification Date: 08/06/2011
Notification Time: 17:41 [ET]
Event Date: 08/06/2011
Event Time: 11:19 [MST]
Last Update Date: 08/06/2011 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL
| Person (Organization):
BOB HAGAR (R4DO)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 1 | A/R | Y | 100 | Power Operation | 0 | Hot Standby | Event Text AUTOMATIC REACTOR TRIP DUE TO DROPPED CONTROL ELEMENT ASSEMBLY
"On August 6, 2011, at approximately 1119 MST, the Palo Verde Unit 1 reactor tripped from approximately 100% rated thermal power due to a valid Reactor Protection System (RPS) actuation. The actuation was caused by a dropped Shutdown Group Control Element Assembly (CEA) during surveillance testing to exercise the CEAs. Following the reactor trip, one Regulating Group CEA indicated a failure to insert, however the CEA subsequently indicated fully inserted with no additional operator actions approximately 2 minutes after the trip. All CEAs are currently inserted fully into the reactor core. With the exception of the delayed indication of one CEA to fully insert, this was an uncomplicated reactor trip. No emergency classification was required per the Palo Verde Emergency Plan. No automatic or manual ESF actuations occurred and none were required. Safety related electrical buses remained energized during and following the reactor trip. The Emergency Diesel Generators did not start and were not required. The offsite power grid is stable. No major equipment was inoperable prior to the event that contributed to the event.
"Unit 1 is stable at normal operating temperature and pressure in Mode 3."
Decay heat is being removed via the steam generators to the main condenser using the turbine bypass valves.
The licensee notified the NRC Resident Inspector. | |