| U.S. Nuclear Regulatory Commission
Operations Center Event Reports For
10/10/2018 - 10/11/2018 ** EVENT NUMBERS ** |
| Agreement State | Event Number: 53638 | Rep Org: CALIFORNIA RADIATION CONTROL PRGM
Licensee: GEOCON, INC.
Region: 4
City: SAN DIEGO State: CA
County:
License #: 3924-37
Agreement: Y
Docket:
NRC Notified By: L. ROBERT GREGER
HQ OPS Officer: RICHARD SMITH | Notification Date: 10/03/2018
Notification Time: 10:57 [ET]
Event Date: 09/28/2018
Event Time: 00:00 [PDT]
Last Update Date: 10/03/2018 | Emergency Class: NON EMERGENCY
10 CFR Section:
AGREEMENT STATE
| Person (Organization):
THOMAS FARNHOLTZ (R4DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
ILTAB (EMAIL)
CNSNS (MEXICO) (EMAIL) | | This material event contains a "Less than Cat 3" level of radioactive material. | Event Text AGREEMENT STATE - STOLEN DENSITY GAUGE
The following was received via email from the State of California:
"On October 2, 2018, at approximately 0830 [PDT] the, Radiation Safety Officer (RSO) for Geocon, Inc. contacted [California Radiologic Health Branch] RHB Brea concerning the moisture/density gauge, Troxler, model 3440, serial #33877 (Cs-137, 0.333 gigaBecquerel; Am-241, 1.6 gigaBecquerel) that had been stolen along with a transport vehicle parked in San Ysidro, CA, at approximately 0600 to 0700 [PDT], on Friday morning, September 28, 2018.
"The authorized user whose truck was stolen did not inform the RSO until 1000 to 1030 [PDT] on Monday, October 1, 2018, of the stolen radioactive gauge. The RSO has contacted local law enforcement in San Diego and is awaiting the completed police report, a copy of which he will send to RHB Brea to be included as part of this report. The RSO will contact local newspapers to attempt to retrieve the stolen radioactive gauge as well as notifying local servicing vendors of radioactive gauges to be alert for the serial number of the stolen gauge in case it turns up for service. The investigation will continue to determine if the radioactive gauge can be recovered in a reasonable time frame. California Notices of Violation will be issued to the licensee for failure to report the loss in a timely manner, and loss of control of the radioactive material."
California Report No. 5010-100218
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 |
| Agreement State | Event Number: 53639 | Rep Org: CALIFORNIA RADIATION CONTROL PRGM
Licensee: SANTA CLARA VALLEY HEALTH AND HOSPITAL SYSTEM
Region: 4
City: SAN JOSE State: CA
County:
License #: 0741-43
Agreement: Y
Docket:
NRC Notified By: ROBERT GREGER
HQ OPS Officer: RYAN ALEXANDER | Notification Date: 10/03/2018
Notification Time: 12:06 [ET]
Event Date: 09/28/2018
Event Time: 00:00 [PDT]
Last Update Date: 10/03/2018 | Emergency Class: NON EMERGENCY
10 CFR Section:
AGREEMENT STATE
| Person (Organization):
THOMAS FARNHOLTZ (R4DO)
NMSS_EVENTS_NOTIFICATION (EMAIL) | Event Text AGREEMENT STATE - UNDERDOSAGE OF YTTRIUM 90 THERASPHERES
The following was received via email from the State of California:
"On 09/28/18, [the Radiation Safety Officer] RSO initially contacted [Radiologic Health Branch] RHB to report a problem related to patient therapy treatment with Yttrium 90 TheraSpheres performed on 09/28/18. The intended activity of the dosage was 11.9 milliCurie, but only approximately 36 percent was delivered to the target tissue based on the measurement of activity remaining in the delivery system after the procedure. The desired dose for the target volume was 135 Gy and the dose delivered was 49 Gy. At the time of the RSO contact, the licensee was uncertain whether the problem was due to patient stasis or an issue with the delivery system (e.g., a kink in the catheter).
"On 10/02/18, RHB received an email from the RSO stating that the physician (Authorized User) had used a micro catheter on the thinner end and it was very tortuous and made the resistance in the circuit higher than the administration box can tolerate such that the delivery system was not able to work properly in this situation. Licensee stated that the problem was not due to patient stasis.
"The licensee will submit a written report in accordance with 10 CFR 35.3945(d)."
California Report No. 5010-092818
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. |
| Agreement State | Event Number: 53640 | Rep Org: NE DIV OF RADIOACTIVE MATERIALS
Licensee: TERRACO CONSULTANTS INC
Region: 4
City: OMAHA State: NE
County:
License #: 01-58-01
Agreement: Y
Docket:
NRC Notified By: JULIA SCHMITT
HQ OPS Officer: RYAN ALEXANDER | Notification Date: 10/03/2018
Notification Time: 15:16 [ET]
Event Date: 10/03/2018
Event Time: 00:00 [CDT]
Last Update Date: 10/09/2018 | Emergency Class: NON EMERGENCY
10 CFR Section:
AGREEMENT STATE
| Person (Organization):
THOMAS FARNHOLTZ (R4DO)
NMSS_EVENTS_NOTIFICATION (EMAIL) | Event Text AGREEMENT STATE - LOSS OF CONTROL AND POSSIBLE DAMAGE OF MOISTURE DENSITY GAUGE
At 1355 CDT on 10/3/18, the Nebraska Office of Radiological Health was notified by the Corporate Radiation Safety Officer (RSO) that a licensed moisture density gauge was run over by a large piece of construction equipment on a construction site in Omaha, NE. At the time of the notification to the State, the Corporate RSO did not know which of the licensee's gauges was involved in the incident, nor the device model number, isotope, or quantity.
Staff from the Nebraska Office of Radiological Health were dispatched and are enroute to the event site to meet the licensee's Assistant RSO to assess the possible damage to the gauge and obtain further information. No injuries related to the event were reported to the State and no offsite emergency services support were requested.
* * * UPDATE ON 10/5/2018 AT 0945 EDT FROM HOWARD SHUMAN TO ANDREW WAUGH * * *
Contamination swipes verified the source of the gauge to be intact. The gauge's source rod was broken during the event and the source had to be manually retracted into the shielded position. The gauge is currently at Terraco.
The moisture density gauge is a Troxler Model 3440 (serial number: 30122).
Notified R4DO (Farnholtz) and NMSS Event Notifications (email).
* * * UPDATE ON 10/5/2018 AT 1725 EDT FROM LARRY HARISIS TO DONG PARK * * *
The following was received via email from the State of Nebraska:
"Nebraska Department of Health and Human Services, Office of Radiological Health was notified on October 3, 2018, by the Radiation Safety Officer (RSO) from Terracon, Inc (Nebraska license 01-58-01) that a portable nuclear moisture density gauge was damaged at a temporary job site. [The licensee authorized user] said that he arrived on the jobsite in Omaha, NE to perform moisture density measurements for Peter Kiewit Construction (general contractor) that was going to be pouring concrete later that afternoon by JR Barger & Sons Concrete Contractors (subcontractor). When [the licensee authorized user] arrived, he parked his vehicle near the work area and assessed the work area. He noticed that there were trucks and other heavy machinery working in the area. [The licensee authorized user] proceeded to take the Troxler portable nuclear moisture density gauge (model 3440, serial number 30122 containing 9 mCi of Cs-137 and 44 mCi of Am-241:Be) out of his vehicle and placed it on the ground where moisture density measurements were to be made. While performing a moisture density measurement with the Cs-137 source deployed from the protective housing, a skid loader backed up and hit the portable gauge. Fortunately, [the licensee authorized user] was able to dive out of the way with the back of the skid loader hitting the back of [the licensee authorized user's] arm. The extent of [the licensee authorized user's] injury is unknown.
"[The licensee authorized user] indicated he then proceeded to inform the skid loader to stop but said he continued without acknowledgement. [The licensee authorized user] was then able to get the attention of [the construction project supervisor] to inform him what just transpired. [The licensee authorized user] said that [the construction project supervisor] was not interested in stopping work for the damaged gauge and proceeded to tell [the licensee authorized user] [profanity] or we will call your boss . At this time, [the licensee authorized user] indicated that [an employee] picked up the damaged gauge and threw it to an area outside the work location. An assumption was made of the [the employee's] whole body dose of 571.1 millirem, assuming that he carried the gauge at one centimeter from the trunk of the body and that it took him one minute to move the gauge.
"[The licensee authorized user] said he then called [the Omaha RSO] and informed him of what just happened. [The Omaha RSO] then called the Corporate RSO. [The Omaha RSO] was then dispatched to the area with a survey meter and to assist [the licensee authorized user]. [The Corporate RSO] informed [the Nebraska Department of Health and Human Services (DHHS), Office of Radiological Health Manager]. [The Nebraska DHHS, Office of Radiological Health Manager] dispatched [personnel] to the scene.
"Meanwhile at the jobsite, [the licensee authorized user] maintained surveillance of the gauge and informed personnel to stay away from where the gauge was located. [The Omaha RSO] said that when he arrived, a radiation survey of the surveillance area and gauge was made. Radiation levels at the surveillance area was about 0.5 mR/hr and the gauge was 10 mR/hr, nearest to the extended Cs-137 source and the source was stuck into the ground to provide additional shielding. Calculations indicated that the exposure rate at the 15 foot exclusion boundary would have been 0.04 mR/hr.
"When Nebraska DHHS, Office of Radiological Health staff arrived, another confirmatory radiation survey of the gauge was completed with a result of 10.5 mR/hr. The gauge was also observed to have the source rod extended into the ground and part of the trigger mechanism was broken and sheared off. A wipe test was performed on the source rod with nip tongs and was reading the same as background. The portable gauge was then manipulated to place the Cs-137 source rod assembly back into the shielded position. After an unsuccessful attempt was made, the sliding spring lock was still open and was emitting 385 mR/hr on contact of the port hole. [The Omaha RSO] was able to clear off the excess mud and dirt on the port hole using the nip tongs and the sliding spring lock was shut. Another wipe test was completed and read at background. A radiation survey of the portable gauge confirmed that the Cs-137 source was in the shielded position and measured 20.8 mR/hr.
"[The Omaha RSO] placed the portable gauge back in the shipping container and duct tape was applied to prevent any movement of the source rod from the shielded position. A radiation survey of the transport case was performed with the portable gauge inside and the highest was 8.9 mR/hr on contact and 0.4 mR/hr at 3 feet. The listed TI [Transportation Index] of the package was labeled as 0.6 mR/hr. [The Omaha RSO] stated that he will contact InstroTek to either repair or dispose of the gauge upon their return to the Omaha office.
"An investigation is currently underway and the event is not closed."
Notified R4DO (Farnholtz) and NMSS Event Notifications (email).
* * * UPDATE ON 10/9/2018 AT 1624 EDT FROM HOWARD SHUMAN TO OSSY FONT * * *
The State of Nebraska submitted the full report. The detailed information was previously provided via email. The item is still open pending a reconstruction of the dose received by the employee who picked up the damaged gauge.
Incident Report No: NE180006
Notified R4DO (Gepford) and NMSS Event Notifications (email). |
| Agreement State | Event Number: 53641 | Rep Org: TEXAS DEPT OF STATE HEALTH SERVICES
Licensee: DESERT NDT LLC
Region: 4
City: ABILENE State: TX
County:
License #: L06462
Agreement: Y
Docket:
NRC Notified By: ART TUCKER
HQ OPS Officer: PHIL NATIVIDAD | Notification Date: 10/03/2018
Notification Time: 15:11 [ET]
Event Date: 10/02/2018
Event Time: 00:00 [CDT]
Last Update Date: 10/03/2018 | Emergency Class: NON EMERGENCY
10 CFR Section:
AGREEMENT STATE
| Person (Organization):
THOMAS FARNHOLTZ (R4DO)
NMSS_EVENTS_NOTIFICATION (EMAIL) | Event Text AGREEMENT STATE REPORT - DAMAGED RADIOGRAPHY SOURCE
The following was received via email from the State of Texas:
"On October 3, 2018, the Agency [Texas Department of State Health Services] was notified by the licensee's radiation safety officer (RSO) that one of their radiography crews had reported they could not retract a 22 Curie Iridium-192 source into a SPEC 150 exposure device. The crew was working at a remote job site [in Carrizo Springs, TX]. The exposure device was sitting on a pipe rack. During an exposure (not the first one) the device fell off the pipe rack, hitting the guide tube, and crimping the tube to a point where the source could not be retracted back into the device.
"The crew contacted the RSO and a retrieval team was sent to the location. The source was positioned in the collimator and covered with bags of lead shot. The retrieval team was able to cut the protective coating off of the guide tube and, using a pair of pliers, reshape the guide tube until the source could be retracted to the fully locked position.
"No member of the general public received an exposure from this event. The highest dose received by an individual responding to this event was 40 millirem."
Texas Incident: I-9616 |
| Power Reactor | Event Number: 53656 | Facility: SOUTH TEXAS
Region: 4 State: TX
Unit: [1] [2] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: SILVESTRE ROMERO JR.
HQ OPS Officer: STEVEN VITTO | Notification Date: 10/10/2018
Notification Time: 01:29 [ET]
Event Date: 10/09/2018
Event Time: 00:00 [CDT]
Last Update Date: 10/10/2018 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
| Person (Organization):
HEATHER GEPFORD (R4DO)
CYBER ASSESSMENT (EMAIL) | | Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 1 | N | N | 0 | Cold Shutdown | 0 | Cold Shutdown | | 2 | N | Y | 100 | Power Operation | 100 | Power Operation | Event Text UNPLANNED LOSS OF EMERGENCY RESPONSE EQUIPMENT
"At 2115 CST on October 9, 2018, South Texas Project Electric Generating Station (STPEGS) experienced an unplanned loss of the Integrated Computer System (ICS) to the Emergency Operations Facility (EOF). The loss of ICS resulted in a major loss of emergency assessment capability to the STPEGS Emergency Operations Facility (EOF) for greater than 75 minutes. Assessment capability has been verified to be available in the Unit 1 and Unit 2 Technical Support Centers (TSC) and the Unit 1 and Unit 2 Control Rooms.
"This report is being made pursuant to 10 CFR 50.72(b)(3)(xiii), any event that results in a major loss of emergency assessment capability, off site response capability, or off site communications ability.
"The NRC Resident Inspector has been informed."
The cause of the unplanned loss is currently being investigated and compensatory measures are in place.
* * * UPDATE ON 10/10/18 AT 0951 EDT FROM RICK NANCE TO PHIL NATIVIDAD * * *
Integrated Computer System was returned to service as of 0810 CDT on October 10, 2018.
Notified R4DO (Gepford) and CAT via email. |
| !!!!! THIS EVENT HAS BEEN RETRACTED.THIS EVENT HAS BEEN RETRACTED !!!!! | | Power Reactor | Event Number: 53657 | Facility: QUAD CITIES
Region: 3 State: IL
Unit: [1] [2] []
RX Type: [1] GE-3,[2] GE-3
NRC Notified By: JEFFREY EASLEY
HQ OPS Officer: STEVEN VITTO | Notification Date: 10/10/2018
Notification Time: 03:26 [ET]
Event Date: 10/09/2018
Event Time: 00:00 [CDT]
Last Update Date: 11/14/2018 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(v)(D) - ACCIDENT MITIGATION
| Person (Organization):
AARON McCRAW (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 | | 2 | N | Y | 100 | Power Operation | 100 | Power Operation | Event Text CONTROL ROOM EMERGENCY VENTILATION AC SYSTEM INOPERABLE
"On October 9, 2018 at 2002 CDT the Control Room Emergency Ventilation Air Condition (CREV AC) system was in the process of being returned to service following maintenance. During the return to service, the end bell on the CREV AC Condenser developed a significant leak requiring isolation. No work was performed on the CREV AC Condenser during the work window.
"The CREV AC system maintains a habitable control room environment and ensures the operability of components in the control room emergency zone during accident conditions.
"This notification is being made in accordance with 10CFR50.72(b)(3)(v)(D), "Event or Condition That Could Have Prevented Fulfillment of a Safety Function " because the CREV system is a single train system required to mitigate the consequences of an accident."
The NRC Resident Inspector has been notified.
* * * RETRACTION AT 1714 EST ON 11/14/2018 FROM JASON SWAIN TO JEFF HERRERA * * *
"The purpose of this notification today (November 14, 2018) is to retract the ENS Report made on October 10, 2018 at 0326 EDT (ENS Report #53657).
"Upon further investigation, it was determined that while the CREV AC system was out of service for planned maintenance and inoperable, the return to service valve sequencing caused an in-rush of residual heat removal service water (RHRSW) at 300 psig dead-heading into the refrigeration condensing unit (RCU). Previous normal sequencing had refilled the RCU with service water which is supplied at 100 psig. This unexpected higher than normal pressure on the RCU end bell gasket (rated at 150 psig) caused the gasket to be pushed from its normally seated position to allow a leak path. The gasket was not previously leaking; upon removal was inspected and no evidence of premature cracks or tears were found.
"The CREV AC system leak was induced by an improper coordination of return to service activities at the time of discovery, and the leak path was not previously present. This was not a latent failure. As such, a pre-exiting condition that could have prevented the fulfillment of a safety function did not exist, and based on this information, ENS Report# 53657 is being retracted.
"Note: On October 11, 2018 at 1330 hours CDT, the CREV RCU System gaskets were replaced and the system was returned to service under the properly sequenced tagout and was returned to Operable status.
"The NRC Resident Inspector has been notified. "
Notified the R3DO (Peterson). |
| Part 21 | Event Number: 53660 | Rep Org: ABB INC
Licensee: ABB INC
Region: 1
City: BLAND State: VA
County:
License #:
Agreement: Y
Docket:
NRC Notified By: JOEY CHANDLER
HQ OPS Officer: VINCE KLCO | Notification Date: 10/11/2018
Notification Time: 09:39 [ET]
Event Date: 09/10/2018
Event Time: 00:00 [EDT]
Last Update Date: 10/11/2018 | Emergency Class: NON EMERGENCY
10 CFR Section:
21.21(d)(3)(i) - DEFECTS AND NONCOMPLIANCE
| Person (Organization):
AARON McCRAW (R3DO)
PART 21/50.55 REACTORS (EMAIL) | Event Text PART 21 REPORT - DEFECT ASSOCIATED WITH DRY TYPE TRANSFORMER
The following information was received by from ABB INC by facsimile:
"1. This letter provides a notification of a defect associated with dry type transformer serial # 24-26458. The failure was caused by the breakdown of layer to layer insulation within the 4160 volt winding due to dielectric stress. Deterioration of the insulation resulted in an internal fault within the bravo phase 4160 volt winding, triggering a ground fault trip shutdown of equipment. This failure was reported by Exelon's Clinton Nuclear Station and it is the only known reported occurrence of safety related transformer failure caused by the breakdown of layer to layer insulation. Information is provided as specified in 10 CFR 21 paragraph 21.21(d)(4).
"2. Notifying individual: Joey Chandler, Plant Manager, ABB ([PGTR] Power Grids Transformer Division, US), 171 Industry Drive, Bland, VA 24315.
"3. Identification of the Subject component: ABB P/N 24-26458 dry type transformer. This transformer is used for stepping down voltage and was intended for providing power to safety related electrical equipment.
"4. Nature of the deviation: The Exelon Clinton Nuclear Generating Station shut down due to a ground fault alarm on the 4160 volt side of the stepdown transformer that provides power to numerous safety-related components at the plant. Subsequent troubleshooting of the problem revealed that the dry-type transformer supplying 480 volt power had dielectrically failed due to apparent internal fault within the Bravo phase. Further investigation of this failure revealed an operational voltage design stress on the Nomex 410 insulation between the 4160 volt winding's layers of conductor of greater than recommended by the manufacturer (DuPont) for a 40 year design life. At the time of failure, the subject transformer had been in operation for approximately 33.5 years and had progressed 37 years and two months into its intended 40 year life given the 10/1980 ship date. ABB has no knowledge of any adverse operational variances over the course of the approximate 33.5 year life of operation to be able to assess or comment on this potential impact in terms of life.
"5. The function of this dry type transformer is to step voltage down from 4160 volts to 480 volts while providing transfer of power to safety related components. Exelon's Clinton Nuclear Power Station has identified this transformer's power transfer to feed safety related equipment. An interruption of this transfer in power would result in a loss of power to the safety related equipment downstream and could potentially result in a compromise in safety.
"6. ABB was notified of this transformer failure on 12/9/2017. This notification was delayed while the failure was being investigated. This investigation is documented in report: Exelon Clinton Failure Analysis_26458_011218 rev5.doc.pdf dated 09/10/2018.
"7. Corrective actions include:
a. Reviewed and verified current electrical engineering safety related design standard for allowable design stress on insulation per DuPont's recommendation for 40 year life. (Complete.)
b. Reviewed the material used for transformer 24-26458. Found only affected safety related product to be isolated to Clinton Nuclear Station, though records may be incomplete as these records have been archived for over 35 years. (Complete.)
c. Re-trained all involved personnel of the 10 CFR 21 reporting requirements, and the need to provide an interim report within 60 days of discovery.
d. ABB worked directly with Clinton Nuclear to ensure all transformers of respective design was replaced with new transformers following ABB's Technical Evaluation for Nuclear 1E Transformer, Rev. 18 which documents operational design stresses be less than or equal to 30 volts / mil of Nomex 410 insulation between layer to layer of conductor for 40 year life.
"8. Recommendation: Because of the possible existence of additional affected transformers, ABB (PGTR) cannot determine the potential for a substantial safety hazard exists at any other licensee's facility. Licensees are requested to evaluate any Gould-Brown Boveri/ITE dry type transformer with the following nameplate identification below. Transformers associated with this identification are recommended to be replaced.
"kVA: 750AA/ 1000 FA
HV: 4160 Delta Connected
LV: 480 Wye Connected
Class: AA/ FA
Type: Vent
Frequency: 60 Hz
Temp Rise: 80 degrees C
Date of Manufacture: 10/1988 and older models
"Questions concerning this notification should be directed to the Quality Manager (Rick Kinder) at the ABB transformer plant in Bland, VA at (276) 688 -3325." |
| Power Reactor | Event Number: 53661 | Facility: BROWNS FERRY
Region: 2 State: AL
Unit: [] [2] []
RX Type: [1] GE-4,[2] GE-4,[3] GE-4
NRC Notified By: CHRIS BENNETT
HQ OPS Officer: BETHANY CECERE | Notification Date: 10/11/2018
Notification Time: 15:37 [ET]
Event Date: 08/16/2018
Event Time: 00:00 [CDT]
Last Update Date: 10/11/2018 | Emergency Class: NON EMERGENCY
10 CFR Section:
50.73(a)(1) - INVALID SPECIF SYSTEM ACTUATION
| Person (Organization):
ANTHONY MASTERS (R2DO) | | Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode | | 2 | N | Y | 100 | Power Operation | 100 | Power Operation | Event Text INVALID ACTUATION OF A GENERAL CONTAINMENT ISOLATION SIGNAL AFFECTING MORE THAN ONE SYSTEM
"This 60-day telephone notification is being made per the reporting requirements specified by 10 CFR 50.73(a)(2)(iv)(A) and 10 CFR 50.73(a)(1) to describe an invalid actuation of a general containment isolation signal affecting more than one system.
"On August 16, 2018, at approximately 1736 CDT, Browns Ferry Nuclear Plant (BFN), Unit 2 experienced an unexpected loss of the 2B Reactor Protection System (RPS). This resulted in Primary Containment Isolation System (PCIS) groups 2, 3, 6, and 8 isolations, and initiation of Standby Gas Treatment Trains A, B, and C and Control Room Emergency Ventilation System Train A. All affected safety systems responded as expected with the exception of the Unit 1 Refuel Zone Supply Fan Outboard Isolation Damper, 1-FCO-64-5, that failed to indicate closed position.
"Plant conditions which initiate PCIS Group 2 actuations are Reactor Vessel Low Water Level (Level 3) or High Drywell Pressure. The PCIS Group 3 actuations are initiated by Reactor Vessel Low Water Level (Level 3) or Reactor Water Cleanup Area High Temperature. The PCIS Group 6 actuations are initiated by Reactor Vessel Low Water Level (Level 3), High Drywell Pressure, or Reactor Building Ventilation Exhaust High Radiation (Reactor Zone or Refuel Zone). The PCIS Group 8 actuations are initiated by Low Reactor Vessel Water Level (Level 3) or High Drywell Pressure. At the time of the event, these conditions did not exist; therefore, the actuation of the PCIS was invalid.
"The cause of the RPS MG [Motor Generator] Set trip was a failed (shorted) operating coil associated with the 480 VAC motor starter inside the control box.
"There were no safety consequences or impact to the health and safety of the public as a result of this event.
"This event was entered into the Corrective Action Program as Condition Reports 1440047 and 1440050.
"The NRC Resident Inspector has been notified of this event." | |