| U.S. Nuclear Regulatory Commission
Operations Center Event Reports For
03/16/2009 - 03/17/2009 ** EVENT NUMBERS ** |
 | !!!!! THIS EVENT HAS BEEN RETRACTED. THIS EVENT HAS BEEN RETRACTED !!!!! | | Power Reactor | Event Number: 44562 | Facility: TURKEY POINT
Region: 2 State: FL
Unit: [3] [4] [ ]
RX Type: [3] W-3-LP,[4] W-3-LP
NRC Notified By: DEWEY BARROW
HQ OPS Officer: JEFF ROTTON | Notification Date: 10/11/2008
Notification Time: 10:23 [ET]
Event Date: 10/11/2008
Event Time: 05:45 [EDT]
Last Update Date: 03/16/2009 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(B) - UNANALYZED CONDITION
| Person (Organization):
SCOTT SHAEFFER (R2)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 3 | N | Y | 100 | Power Operation | 100 | Power Operation | | 4 | N | N | 0 | Hot Standby | 0 | Hot Standby | Event Text UNANALYZED CONDITION DUE TO VENDOR CALCULATION ERROR
"Turkey Point received notification of an error in a vendor calculation methodology regarding the containment building heat transfer. This calculation is used to support containment temperature and pressure as well as heat input to the Component Cooling Water system under design basis accident conditions.
"While validating a new analysis model, it was discovered that the Turkey Point containment steel liner was not included in the analysis of record. This is a non-conservative error in that less heat would be expected to be transferred to the external environment with the presence of the liner. The initial evaluation of the error indicates that at the maximum allowable Ultimate Heat Sink (Intake) temperature, Containment pressure, long-term Containment temperature and Component Cooling Water return temperature could exceed licensing basis limits during a design basis accident.
"Preliminary analysis indicates that under current Ultimate Heat Sink conditions, operability requirements are met."
The licensee notified the NRC Resident Inspector.
* * * UPDATE AT 1642 ON 3/16/09 FROM MCKEE TO HUFFMAN * * *
"The purpose of this update is to retract EN #44562 submitted to the NRC Operations Center on October 11, 2008.
"FPL has performed a detailed evaluation of the impact of errors identified by Westinghouse in the Loss of Coolant Accident (LOCA) containment analysis of record on the operation of Turkey Point Units 3 and 4. The evaluation took into consideration actual ultimate heat sink (intake cooling water - ICW) temperatures, and removed conservatisms used in the LOCA containment integrity analysis and Component Cooling Water (CCW) system analysis. The evaluation confirmed that the Units 3 and 4 containment structures were capable of performing the safety function required by the Technical Specifications. Additionally, after removal of conservatisms in conjunction with a minimum CCW heat exchanger heat removal capability consistent with an ICW temperature of 95 degrees F, and an assumed CCW heat exchanger tube resistance, the long term containment temperature and CCW return temperature would not have exceeded licensing basis limits during a design basis accident.
"The evaluation determined that Turkey Point Units 3 and 4 were not in an unanalyzed condition that significantly degraded plant safety as a result of the containment integrity analysis error and this event is not reportable under 10CFR50.72(b)(3)(ii)(B) criteria. Therefore, EN #44562 is retracted.
"The evaluation described above is documented in the Corrective Action Program in report 2008-31338 ."
The licensee will notify the NRC Resident Inspector. Notified R2DO(Nease). |
| General Information or Other | Event Number: 44895 | Rep Org: WISCONSIN RADIATION PROTECTION
Licensee: AURORA HEALTH CENTER
Region: 3
City: SHEBOYGAN State: WI
County:
License #: 117-1022-01
Agreement: Y
Docket:
NRC Notified By: LEOLA DEKOCK
HQ OPS Officer: DONALD NORWOOD | Notification Date: 03/11/2009
Notification Time: 14:00 [ET]
Event Date: 03/09/2009
Event Time: [CDT]
Last Update Date: 03/11/2009 | Emergency Class: NON EMERGENCY
10 CFR Section:
AGREEMENT STATE
| Person (Organization):
JULIO LARA (R3)
ANGELA MCINTOSH (FSME)
| Event Text AGREEMENT STATE REPORT - PROSTATE BRACHYTHERAPY OVERDOSE
"The Wisconsin Radiation Protection Section (RPS) was notified on 3/10/09 of a possible medical event that occurred on 3/9/09. The medical event occurred at Lombardi Cancer Center, which is affiliated with Aurora Health Center in Sheboygan (RML #117-1022-01).
"The treatment was a permanent prostate brachytherapy implant using I-125 seeds. The intended total dose was 107 Gy and the patient was administered a total dose of 144 Gy. The overdose was discovered on 3/9/09, following review by the dosimetrist.
"The patient was notified on 3/10/09. The referring urologist and the patient's primary care provider were also notified.
"RPS has had telephone communications with the RSO and the Authorized User (AU) and has requested additional documents. The RSO will be unavailable (out-of-town). A team of RPS staff will be conducting a site visit at the facility when the AU returns."
Wisconsin Radiation Protection Section Event Report ID Number: WI090003.
An on-site investigation is planned by Wisconsin Radiation Protection Section beginning 3/12/09. A follow-up report will be issued after the investigation is completed.
A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient. |
| General Information or Other | Event Number: 44896 | Rep Org: ABB INC.
Licensee: ABB INC.
Region: 1
City: Florence State: SC
County:
License #:
Agreement: Y
Docket:
NRC Notified By: TERRY MALLOY
HQ OPS Officer: DAN LIVERMORE | Notification Date: 03/11/2009
Notification Time: 15:52 [ET]
Event Date: 03/11/2009
Event Time: [EDT]
Last Update Date: 03/16/2009 | Emergency Class: NON EMERGENCY
10 CFR Section:
21.21 - UNSPECIFIED PARAGRAPH
| Person (Organization):
ANTHONY DIMITRIADIS (R1)
REBECCA NEASE (R2)
JULIO LARA (R3)
THOMAS FARNHOLTZ (R4)
RX PART 21 GROUP (E-MA)
| Event Text PART 21 NOTIFICATION - DEFECTIVE HK AND K-LINE CIRCUIT BREAKER TENSION SPRINGS
The identification of the subject component is as follows: ABB P/N 716359A00 Tension Spring. These springs are used in both HK (Medium Voltage) and K-Line (Low voltage) circuit breakers. In the HK breaker, the spring is used on the racking mechanism to position the racking mechanism interlocking latch. In the K-Line circuit breaker, the spring resets the prop latch mechanism following a circuit breaker trip. Circuit breakers and spare parts procured from ABB between 04/23/2008 and 02/27/2009 may have suspect springs installed.
Nature of the deviation: Micro-cracks in the base of the hooked end of the springs may result in failure of the springs after repetitive cycles. A broken spring could potentially affect the ability of a K-Line or HK breaker to reset and close after an opening operation. Initial report of the nonconformance was generated on 02/11/2009 (NCR #68999JL), reporting that springs failed during mechanical life testing being performed on a K-Line breaker. These springs failed after approximately 2,800 cycles each.
Given the large number of applications for the affected circuit breakers, ABB (Medium Voltage Service) cannot determine if the potential for a substantial safety hazard exists at any licensee's facility if a similar failure of the tension spring occurs. Licensees are requested to evaluate the history of inspections, maintenance practices, and circuit breaker operating cycles for K-Line breakers, and racking cycles for HK breakers to determine if the circuit breaker spring should be replaced immediately or at the next convenient maintenance opportunity. ABB recommends that any suspect spring with greater than 1,400 operating cycles be replaced as soon as possible.
Currently ABB is determining the affected licensees and will notify them on or about March 30, 2009.
* * * UPDATE FROM K. WELBORN TO P. SNYDER AT 0759 ON 3/16/2009 * * *
ABB updated the original report by providing a list of affected customers.
Notified R1DO (DeFrancisco), R2DO (Nease), R3DO (Lara), and R4DO (Hay). |
| General Information or Other | Event Number: 44898 | Rep Org: MARYLAND DEPT OF THE ENVIRONMENT
Licensee: STONE INDUSTRIAL
Region: 1
City: COLLEGE PARK State: MD
County:
License #:
Agreement: Y
Docket:
NRC Notified By: ALAN JACOBSON
HQ OPS Officer: JOE O'HARA | Notification Date: 03/12/2009
Notification Time: 08:55 [ET]
Event Date: 03/06/2009
Event Time: [EDT]
Last Update Date: 03/12/2009 | Emergency Class: NON EMERGENCY
10 CFR Section:
AGREEMENT STATE
| Person (Organization):
ANTHONY DIMITRIADIS (R1)
ANGELA MCINTOSH (FSME)
ILTAB VIA EMAIL ()
|
| This material event contains a "Less than Cat 3" level of radioactive material. | Event Text MISSING STATIC ELIMINATOR CONTAINING POLONIUM-210
"This report is in reference to a lost 13 [inch] Nuclestat ionizer bar that contains Polonium-210. The model number is P-2001-012, and the serial number is A2FS026. [The licensee] entered into a lease agreement for 13 ionizer bars, 2 Nuclecel in-line ionizers, and 1 Nuclecel ion air blower with NRD, LLC to minimize the amount of static present in our operation.
"On Friday, March 6, 2009, it was reported by [the licensee's] Maintenance Department that an ionizer bar was missing from Winder #23. They were in the process of removing all of the ionizer bars from the winders to return them to NRD, LLC. The security cable was found attached to the winder, but it appeared someone had unscrewed the ionizer bar. All bars were attached to the end of the plastic winders with a steel cable and two screws. Upon investigation, [a licensee representative] found [that] the operators [remembered] the ionizer bar [being] present the week of February 23 - 27th on Winder #23, but they [did] not remember seeing the ionizer bar when [they] returned from a two day shutdown on Wednesday, March 4, 2009. After learning [that] the ionizer bar was missing on March 6th, the Plastic Winding Department was shutdown in the afternoon to search for it. About 15 employees searched the entire building including the trash and the building next door that contains old equipment. On Monday, March 9, 2009, the trash from the trash compactor was dumped in the parking lot, and the department searched through it for the missing ionizer bar. Once it was determined the ionizer bar was still missing, [a licensee representative] reported the lost device to [a State of Maryland representative] on March 9th.
"The remaining in-line ionizer bars, Nuclecel in-line ionizers and Nuclecel ion air blower will be returned to NRD, LLC to terminate our lease agreement. We will replace them with carbon bars and electronic air ionizers to reduce static in our operation."
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. |
| General Information or Other | Event Number: 44900 | Rep Org: TEXAS DEPARTMENT OF HEALTH
Licensee: DR. PEPPER
Region: 4
City: IRVING State: TX
County:
License #: G01697
Agreement: Y
Docket:
NRC Notified By: RAY JISHA
HQ OPS Officer: DAN LIVERMORE | Notification Date: 03/12/2009
Notification Time: 15:04 [ET]
Event Date: 03/06/2009
Event Time: [CDT]
Last Update Date: 03/13/2009 | Emergency Class: NON EMERGENCY
10 CFR Section:
AGREEMENT STATE
| Person (Organization):
THOMAS FARNHOLTZ (R4)
JOHN RAMSEY (OIP)
ANDREW MAUER (FSME)
ILTAB EMAIL (ILTA)
|
| This material event contains a "Less than Cat 3" level of radioactive material. | Event Text AGREEMENT STATE REPORT - TWO SOURCES DISPOSED AS SCRAP
"On February 20, 2009 during an internal audit/inspection, it was discovered that two Filtec Model FT 50 level detection devices each with 100 mCi of Am-241 were missing [and] apparently moved off the facility as scrap metal. Notification to state offices were through inappropriate channels and thus Incident Investigation staff were not informed of [the event] until March 12, 2009. A preliminary investigation has determined that the metal scrap along with these devices was subsequently shipped to a mill in India and [has] probably been melted. Specific details of the shipping, route and mode of transport, vendors as well actual location in India are being gathered. The serial numbers are 112733/5393 and 116813/2555."
Texas Incident # I-8618
* * * UPDATE ON 03/13/2009 AT 1400 FROM RAY JISHA TO DAN LIVERMORE * * *
Report received via e-mail:
"The gauges were accidentally removed from the plant and placed into a metal scrap dumpster and picked up from our property by MC3 International Scrap Salvage on December 8, 2008.
"MC3 International Scrap Salvage delivered the mixed shear cut metal to Lone Star Fox Export Metals on December 8, 2008. Lone Star Fox Export shipped the mixed cut metal to India before or around December 13, 2008. The licensee provided a list of 10 containers.
"The mixed metal was sent to Nhava Sheva, India. The licensee does not have any information on the mill in India. They do not have any information on products that may have been produced from the scrap.
"The state is in the process of contacting the scrap metal dealers. Additional information will follow as it is obtained."
Notified R4DO (Farnholtz), FSME EO (McIntosh), OIP (Ramsey), and ILTAB (via email).
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. |
| General Information or Other | Event Number: 44902 | Rep Org: TEXAS DEPARTMENT OF HEALTH
Licensee: DESERT INDUSTRIAL X-RAY LP
Region: 4
City: ABILENE State: TX
County:
License #: 04590
Agreement: Y
Docket:
NRC Notified By: ART TUCKER
HQ OPS Officer: JOHN KNOKE | Notification Date: 03/12/2009
Notification Time: 15:15 [ET]
Event Date: 03/05/2009
Event Time: 16:45 [CDT]
Last Update Date: 03/12/2009 | Emergency Class: NON EMERGENCY
10 CFR Section:
AGREEMENT STATE
| Person (Organization):
THOMAS FARNHOLTZ (R4)
ANDREW MAUER (FSME)
| Event Text SOURCE DISCONNECT FROM RADIOGRAPHY CAMERA DRIVE CABLE
The Agency (State) was notified (at 1645 PDT) by the licensees RSO that they had a source disconnect and that the source was later retracted. The event involved an INC IR-100 camera containing a 94 curie Ir-192 source. The source was in use for about one week, about 6 jobs. A local Texas inspector went to the site to investigate the event.
The licensee later notified the Agency (State) that in this case, the connector crimped fitted on the source pig tail had separated from the source drive cable. The two individuals who returned the source to the camera housing received 425 millirem by self reading dosimeter for one worker, and between 750 and 800 millirem calculated for the other worker. The RSO stated that neither worker exceeded the annual DDE limit. TLD's for the workers involved have been sent to their processor and the results should be back on 3/9/09. The State of California has been informed of the event.
On March 13, 2009, the RSO notified the Agency (State) that the radiography camera had been packaged and will be returned to the manufacturer today.
Texas Incident # I-8614 |
| Power Reactor | Event Number: 44905 | Facility: PERRY
Region: 3 State: OH
Unit: [1] [ ] [ ]
RX Type: [1] GE-6
NRC Notified By: TOM MORSE
HQ OPS Officer: VINCE KLCO | Notification Date: 03/13/2009
Notification Time: 00:42 [ET]
Event Date: 03/13/2009
Event Time: 00:25 [EDT]
Last Update Date: 03/16/2009 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
| Person (Organization):
JULIO LARA (R3)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 1 | N | N | 0 | Refueling | 0 | Refueling | Event Text PARTIAL LOSS OF PLANT COMPUTER FOR SCHEDULED MAINTENANCE TAKING ERDS OOS
"The Perry Nuclear Power Plant has taken a portion of the Plant Computer out of service for scheduled maintenance. This has resulted in a portion of ERDS being out of service. From 0025 hours EDT on March 13, 2009 for approximately 36 hours, personnel will be performing maintenance activities which result in a partial loss of the Plant Computer. During this planned maintenance, portions of the Safety Parameter Display System (SPDS) and the automatic mode calculation of the Computer Aided Dose Assessment Program (CADAP) will be unavailable.
"In the event of an emergency, plant parameter data will be orally transmitted to the facilities through the Status Board Ring Down circuit with back-up by the Private Branch Exchange, Off Premise Exchange, and various redundant intra-facility circuits throughout the emergency facilities. The dose assessment function will be maintained during the out of service time period by manual input of data into CADAP and, if required, by manual calculation. The ability to open and maintain an 'open line' using the Emergency Notification System will not be affected and will be the primary means of transferring plant data to the NRC as a contingency until the ERDS can be returned to service during the period of unavailability.
"This event is being reported in accordance with 10CFR50.72(b)(3)(xiii), as a condition that results in a major loss of offsite communication capability. A follow-up notification will be made when the maintenance activities are completed and the equipment is restored."
The licensee notified the NRC Resident Inspector.
* * * UPDATE AT 1132 ON 3/14/2009 FROM TONY JARDINE TO MARK ABRAMOVITZ * * *
The plant has extended the expected plant computer outage time by 60 hours (ending 3/16/2009 at 2400).
Notified the R3DO (Lara).
* * * UPDATE AT 1907 EDT ON 3/16/2009 FROM TOM STEC TO BILL HUFFMAN * * *
The licensee has extended the expected outage time for the plant computer maintenance by an additional 24 hours. Repairs are now expected to be completed by 2400 EDT on 3/17/09.
The licensee will notify the NRC Resident Inspector. R3DO(Ring) notified. |
| Power Reactor | Event Number: 44907 | Facility: MONTICELLO
Region: 3 State: MN
Unit: [1] [ ] [ ]
RX Type: [1] GE-3
NRC Notified By: DAVID BARNETT
HQ OPS Officer: HOWIE CROUCH | Notification Date: 03/16/2009
Notification Time: 12:34 [ET]
Event Date: 03/16/2009
Event Time: 09:00 [CDT]
Last Update Date: 03/16/2009 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(xi) - OFFSITE NOTIFICATION
| Person (Organization):
MARK RING (R3)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 1 | N | N | 0 | Cold Shutdown | 0 | Cold Shutdown | Event Text OFFSITE NOTIFICATION DUE TO FISH KILL DURING ROUTINE SHUTDOWN
The licensee notified state and local authorities of a fish kill that occurred during a routine plant shutdown for refueling. The fish kill, in the Mississippi River, was monitored for a two day period.
Notifications were made to the State of Minnesota Emergency Management Agency, Wright County Sheriff's Office, and Sherburne County Sheriff's Office.
The licensee has notified the NRC Resident Inspector. |
| Power Reactor | Event Number: 44908 | Facility: TURKEY POINT
Region: 2 State: FL
Unit: [3] [4] [ ]
RX Type: [3] W-3-LP,[4] W-3-LP
NRC Notified By: JOSEPH MCKEE
HQ OPS Officer: HOWIE CROUCH | Notification Date: 03/16/2009
Notification Time: 13:02 [ET]
Event Date: 03/16/2009
Event Time: 10:45 [EDT]
Last Update Date: 03/16/2009 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(xi) - OFFSITE NOTIFICATION
| Person (Organization):
REBECCA NEASE (R2)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 3 | N | N | 0 | Hot Shutdown | 0 | Hot Shutdown | | 4 | N | Y | 100 | Power Operation | 100 | Power Operation | Event Text OFFSITE NOTIFICATION DUE TO 1 GALLON OIL SPILL AT FOSSIL UNITS
"On 3/16/09 at 1045, Miami-Dade County was notified of a 1 gallon fuel oil spill from the Turkey Point Fossil Plants. This fuel oil went into a storm drain which drains into the cooling canals used for all four units. The fuel oil spill originated from a leak in a fuel oil heater. This leak has subsequently been isolated.
"At 1141, the Florida State Warning Point was also notified of the oil spill.
"Notification to the Environmental Protection Agency is not required.
"This four hour notification to the NRCOC is required per 10CFR50.72(b)(2)(xi) due to the notification to offsite government agencies."
The licensee will be notifying the NRC Resident Inspector. |
| Research Reactor | Event Number: 44909 | Facility: ARMED FORCES RADIOBIOLOGY RSCH INST
RX Type: 1100 KW TRIGA MARK-F
Comments:
Region: 1
City: BETHESDA State: MD
County: MONTGOMERY
License #: R-84
Agreement: Y
Docket: 05000170
NRC Notified By: STEVE MILLER
HQ OPS Officer: BILL HUFFMAN | Notification Date: 03/16/2009
Notification Time: 13:54 [ET]
Event Date: 03/16/2009
Event Time: 11:23 [EDT]
Last Update Date: 03/16/2009 | Emergency Class: NON EMERGENCY
10 CFR Section:
INFORMATION ONLY
| Person (Organization):
AL ADAMS (NRR)
| Event Text MANUAL TRIP DUE TO FAILURE OF TECHNICAL SPECIFICATION REQUIRED FUEL THERMOCOUPLE
The licensee provided an informational call to inform the NRC Operations Center that it had manually tripped the research reactor from approximately 75% power (750 KW) due to the failure of a core fuel thermocouple that provides a reactor trip function. The technical specifications for the reactor require that two fuel centerline temperature thermocouples that provide a reactor trip function be available while the reactor is operating. The two fuel centerline thermocouples were confirmed to be functioning properly during a pre-startup surveillance earlier this morning. While at power the operators noticed fluctuations in one of the two thermocouple readouts. After about 4 minutes, it was concluded that one of the thermocouples was not functioning properly and the reactor was manually tripped to be in compliance with the technical specification action statement. The licensee was within technical specifications as soon as the reactor was tripped. The reactor did not trip automatically with the failure of the thermocouple because the failed thermocouple was providing a low temperature input into the reactor protection logic.
There were no other issues with the research reactor and the licensee noted that it was not required to make an immediate notification to the NRC Operations Center per its license. The licensee had also notified the NRC inspector for this facility (Pat Isaac) of this event. |
| Power Reactor | Event Number: 44910 | Facility: BRUNSWICK
Region: 2 State: NC
Unit: [ ] [2] [ ]
RX Type: [1] GE-4,[2] GE-4
NRC Notified By: WILLIAM WOODBURY
HQ OPS Officer: BILL HUFFMAN | Notification Date: 03/16/2009
Notification Time: 20:17 [ET]
Event Date: 03/16/2009
Event Time: 12:25 [EDT]
Last Update Date: 03/16/2009 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(v)(B) - POT RHR INOP
| Person (Organization):
REBECCA NEASE (R2)
|
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 2 | N | N | 0 | Refueling | 0 | Refueling | Event Text SHORT TERM LOSS OF SUPPLEMENTAL SPENT FUEL COOLING
"On 3/16/2009 at 12:25, Unit 2 was in Mode 5 (Refueling), during natural circulation mode to support maintenance on the common suction line to both loops of Residual Heat Removal (RHR) Systems, both Secondary Side Supplemental Spent Fuel Pool Cooling pumps tripped. Earlier on the same day at 05:50, the unit had been placed into natural recirculation mode when the RHR Loop 'A' was secured from the Shutdown Cooling mode of operation. In this mode the 'A' loop of Supplemental Spent Fuel Pool Cooling coupled with the 'A' loop of the Fuel Pool Cooling system was designated as the primary decay heat removal system and the 'B' loop of both systems were designated as the backup decay heat removal system. At the time of the secondary pump trips, the RHR Common loop suction was being placed under clearance.
"The trip of the Secondary Side pumps caused a loss of the entire ('A' and 'B' loops) Supplemental Spent Fuel Pool Cooling System and resulted in a partial loss of the decay heat removal system. Both 'A' and 'B' loops of the Fuel Pool Cooling System remained in service. In addition, Unit 2 remained in an Active LCO for Technical Specification 3.9.7 due to securing all loops of Shutdown Cooling at 05:50. The Supplemental Spent Fuel Pool Cooling system was restored to operation at 12:45, and actions to restore RHR to the Shutdown Cooling Mode of operation were in progress.
"RHR 'A' Loop was restored to on available status at 12:59, and placed in the Shutdown Cooling mode of operation at 14:47.
"Based on the combination of systems out of service, and no supporting calculation to ensure Spent Fuel Pool Temperature remains below 150 degrees Fahrenheit (as described In the UFSAR), this could have prevented the fulfillment of the safety function for Decay Heat Removal.
"The safety significance of the loss of primary decay heat removal was minimal. During the loss of the Supplemental Spent Fuel Pool Cooling system, reactor vessel temperature rose by approximately 0.5 degrees Fahrenheit. Total heatup of the Spent Fuel Pool was less than 2 degree Fahrenheit. Allowed Technical Specification Heatup rate is limited to 100 degrees Fahrenheit per hour which the was not approached, or exceeded, at any time. Calculated time to boil (with no cooling supplied) was greater than 24 hours; transient was brief in duration and did not challenge time to boil. At all times, the Fuel Pool Cooling System remained in service. There were no challenges to the reactor pressure vessel, or the fuel, due to the loss of decay heat removal.
"The Supplemental Spent Fuel Pool Cooling System was restored to operation at 12:45. RHR was restored to service in the shutdown cooling made of operation at 14:47."
The licensee has notified the NRC Resident Inspector. | |