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| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 55818 | 2 April 2022 18:45:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Unusual Event Declared Due to a Fire at the 3B Reactor Feedwater Pump | The following information was provided by the licensee via fax: At 1345 CDT, Browns Ferry declared a Notification of Unusual Event due to a fire at the 3B Reactor Feedwater Pump within the Turbine Building which was not extinguished within 15 minutes. Subsequently, the fire was extinguished at 1402 CDT. Unit 3 remains in Mode 1 at approximately 9.5 percent rated thermal power (RTP). Unit 1 and 2 remain at 100 percent RTP and unaffected. The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance: The fire began at 1332 CDT. It is believed that the fire was in the oil system of the Feedwater Pump. The fire was extinguished by the on-site fire brigade. No off-site assistance was requested. The Unusual Event was declared under Emergency Action Level HU-4. The licensee notified the NRC Resident Inspector and required State and local government agencies. Unit 3 is currently stable. Notified DHS-SWO, FEMA Ops Center, and CISA Central Watch Officer, and FEMA NWC, DHS NRCC THD Desk, and DHS NuclearSSA via email.
The Notification of Unusual Event was exited at 1544 CDT. Notified R2DO (Miller), IR-MOC (Kennedy), NRR-EO (Felts), DHS-SWO, FEMA Ops Center, and CISA Central Watch Officer. | Feedwater | |
| ENS 53922 | 10 March 2019 05:12:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Notice of Unusual Event Due to Loss of Offsite Power | At 0012 EST on 3/10/2019, Browns Ferry Unit-3 declared an Unusual Event due to a spurious trip of the generator breaker, resulting in a loss of AC power to the 4 kV shutdown boards greater than 15 minutes. All diesel generators started and loaded to supply onsite power. The reactor auto-scrammed, with all rods fully inserting. The Main Steam Isolation Valves opened and shutdown cooling was being conducted via the condenser. The licensee will exit the emergency declaration once offsite power is restored. There is no estimated restart date. Browns Ferry Unit 1 remains in Mode-1 (100%), Unit 2 remains in Mode-5 for a refueling outage. The NRC Resident Inspector has been notified. This event is related to EN 53923. Notified DHS SWO, FEMA Operations Center, DHS NICC, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email).
At 1310 CDT, Browns Ferry Unit-3 exited the Unusual Event when 161 kV lines were made available. The licensee is executing procedures for securing the diesel generators while alternate offsite power methods are utilized. Switchyard damage evaluation is in progress. The licensee will notify the NRC Resident Inspector. Notified R2DO (Desai), R2RA (Haney), DNRR (Nieh), NRR EO (Miller), and IRD (Grant). Notified DHS SWO, FEMA Operations Center, DHS NICC, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email). | Main Steam Isolation Valve Shutdown Cooling | |
| ENS 53558 | 22 August 2018 05:00:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Notification of Unusual Event Declared Due to Fire | On 08/22/2018 at 1803 hours CDT, Browns Ferry Nuclear Plant declared an Unusual Event per EAL HU4, a fire potentially degrading the level of safety of the plant. At 1748 CDT Unit 1 received a call reporting smoke coming from the 480V Condensate Demineralizer Panel 3 in the Unit 3 turbine building elevation 557'. At approximately 1803 (CDT), the incident commander on the scene confirmed a fire inside the panel and all three units entered 0-AOI-26-1, Fire Response. The board was subsequently de-energized by operations personnel and the fire was extinguished at 1806 CDT. SM (Shift Manager) exited EAL HU4 and all three units exited 0-AOI-26-1 at 1840 CDT. Fire operations remain on scene to monitor. A team is being assembled for damage assessment and recovery. The fire did not affect any safety systems, no plant transients resulted, and no injuries were reported. This event is reportable within 1 hour IAW 10 CFR 50.72(a)(1)(i). The NRC Resident inspector has been notified. Notified DHS SWO, FEMA Ops, DHS NICC, FEMA NWC (email) and NuclearSSA (email). | ||
| ENS 53462 | 20 June 2018 05:00:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Notification of Unusual Event Declared Due to Toxic Gas Release | On June 20, 2018 at 1003 CDT, the licensee declared a Notification of Unusual Event based on Emergency Action Level (EAL) 6.5.U, toxic gas release on site. The Notification of Unusual Event was terminated at 1025 CDT. The toxic gas release occurred when site personnel were filling a fire suppression carbon dioxide (CO2) tank outside the diesel generator building. The relief valve in the common diesel generator room for Unit 1 and 2 diesel generators inadvertently lifted causing a toxic gas environment by releasing CO2 into the room. The licensee terminated the tank fill stopping the release of CO2, and with the door to the room being opened, the gas cleared in about 20 minutes. The licensee has notified the NRC Resident Inspector. Notified DHS SWO, FEMA Ops, DHS NICC, FEMA NWC (email) and NuclearSSA (email). | ||
| ENS 53247 | 7 March 2018 17:05:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Notification of Unusual Event Declared | The licensee declared an Unusual Event based on Emergency Action Level (EAL) 6.7.U and entry into the site Security Plan. All required actions or compensatory measures have been completed. The Notice of Unusual Event was terminated at 1142 CST. There was no impact to the operation of any of the units at the Browns Ferry site. The licensee has notified the NRC Senior Resident Inspector. See EN #53248. Notified DHS SWO, FEMA Ops, DHS NICC, FEMA NWC (email) and NuclearSSA (email).
The licensee provided additional information regarding the event. Notified the R2DO (Musser), IRD MOC (Gott), NRR EO (Miller). | ||
| ENS 52587 | 2 March 2017 18:30:00 | 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Notification of Unusual Event Declared | At 1230 CST, the licensee declared a notification of unusual event based on Emergency Action Level 6.7-U, a non-hostile security event, due to introduction of contraband into the protected area. All required actions have been completed. There was no impact to the operation of any of the units at the Browns Ferry site. The licensee has notified the NRC Resident Inspector. See EN #52586. Notified DHS SWO, FEMA Ops, DHS NICC, FEMA NWC (email) and NuclearSSA (email).
At 1500 CST, the licensee terminated the notification of unusual event. The licensee has notified the NRC Resident Inspector. Notified R2DO (McCoy), NRR EO (King), and IRD (Grant). Notified DHS SWO, FEMA Ops, DHS NICC, FEMA NWC (email) and NuclearSSA (email). | ||
| ENS 51850 | 6 April 2016 20:45:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release 10 CFR 50.72(a)(1)(i), Emergency Class Declaration | Unusual Event Declared Due to Main Steamline High High Radiation Condition | At 1545 CDT on 04/06/16 Browns Ferry Unit 3 declared and exited the declaration of an unusual event due to a main steam line high high radiation condition. Power to Unit 3 was reduced to 91 percent power. The high radiation condition alarm cleared at 1526 CDT. Browns Ferry Unit 3 reported that the high radiation conditions were due to resin intrusion from the condensate demineralizers into the reactor and hydrogen water chemistry was a potential contributor to the event. The cause is still under investigation. The NRC Resident Inspector has been notified. State and Local notifications were made. Notified DHS SWO, FEMA Ops Center, NICC Watch Officer, FEMA NWC and Nuclear SSA (email).
At 1941 (CDT) BFN (Brown's Ferry) determined this notification to be potentially newsworthy due to receiving notification that counties (surrounding the plant) were alerted of this event. No plant conditions changed. The licensee may issue a press release. The licensee will notify the NRC Resident Inspector. Notified R2DO (Nease). | Main Steam Line | |
| ENS 46793 | 27 April 2011 22:01:00 | 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation 10 CFR 50.72(a)(1)(i), Emergency Class Declaration 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Notification of Unusual Event Due to Loss of Offsite Power | At 1701 CDT, the licensee declared a Notification of Unusual Event under Emergency Action Level 5.1U due to loss of offsite power for >15 minutes. The loss of offsite power occurred at 1635 CDT and was due to severe weather and winds in the vicinity. When offsite power was lost, all 3 units automatically scrammed. The units are currently stable in Mode 3 with their respective 4KV busses being supplied by the onsite Emergency Diesel Generators(EDG). The 161KV Athens line is the only offsite power source energized. All onsite safe shutdown equipment is available with the exception of the Unit 3 "B" EDG which was out of service for planned maintenance.
The system actuations that occurred during the loss of offsite power were actuations of the Reactor Protection System, Primary Containment Isolation System (PCIS) and Emergency Diesel Generators. All primary containment valves actuated by the PCIS operated as expected. Unexpectedly, the Unit 3 "B" Main Steam Isolation Valve indicates intermediate. Unit 1 High Pressure Coolant Injection actuated when reactor water level reached -45". Reactor Core Isolation Cooling (RCIC) was already initiated at the time.
Following the loss of offsite power only 12 of the required 100 offsite emergency sirens are operable. The licensee will inform both state/local agencies and the NRC Resident Inspector. Notified R2IRC (Wert) of this update.
As a result of the loss of offsite power, the Diesel-driven Fire Pump auto-started. While the pump was running, the licensee discovered that approximately one quart of oil had leaked from the fire pump into the cold water channel which discharges into navigable waterways. The licensee confirmed this at 1950 CDT by visually identifying a sheen in the channel. The licensee notified the National Response Center of the spill and, in accordance with their site discharge permit, notified the State of Alabama. This constitutes an Offsite Notification in accordance with 10CFR50.72(b)(2)(xi). The licensee notified the NRC Resident Inspector. Notified NRC R2IRC (Wert).
At 2120 CDT, operators on Unit 1 were controlling reactor water level between 2 and 51 inches when RCIC became sluggish and water level dropped to +2" causing a valid RPS Scram signal as well as PCIS signals 2, 3, 6, and 8. All valves operated as expected and all isolations were completed. The licensee notified the NRC Resident Inspector. Notified NRC R2IRC (Wert). * * * UPDATE FROM WILLIAM BAKER TO CHARLES TEAL AT 2338 EDT ON 4/28/11 * * * At 1635 CDT following offsite power grid oscillations (due to inclement weather), and a subsequent Unit 1 power reduction from 100% to 75% to attempt to correct the condition, BFNP experienced a complete loss of the 500kV offsite power system. This resulted in an automatic turbine trip and reactor scram of Units 1, 2 and 3. One 161 kV offsite power system (Athens) remains available. This condition is reportable IAW 10CFR50.72(b)(2)(iv)(B) - Any event or condition that results in actuation of the reactor protection system (RPS) when the reactor is critical except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation (4-hour notification). This notification was reported to NRC (Crouch) at 1723 CDT. At 1701 CDT, a NOUE was declared (EAL Designator 5.1-U) due to loss of normal and alternate voltage to all 4kV SD (Shutdown) Boards for greater than 15 minutes and at least two Diesel Generators supplying power to unit specific 4kV SD Boards. This condition is reportable IAW 10CFR 50.72(a)(1)(i) - The declaration of any of the emergency classes specified in the licensee's emergency plan (1-hour notification). This notification was reported to NRC (Crouch) at 1723 CDT. Following the initial scrams, there were valid actuation signals for RPS (U1/2/3), Containment Isolation Groups 2, 3, 6 and 8 (U1/2/3), HPCI (U1 only), and Emergency Diesel Generators A, B, C, D, 3A, 3C and 3D (EDG 3B is out of service for maintenance). MSIV's (U1 and 3) closed on loss of A and B RPS power, and the U3 B inboard MSIV is indicating 'double lit' (not fully closed) at this time. All other systems responded as expected. This condition is reportable IAW 10CFR50.72(b)(3)(iv)(A) - Any event or condition that results in the valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B), except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation (8-hour notification). The systems with a valid actuation were RPS, Containment Isolation, HPCI and Emergency Diesel Generators. This was reported in an EN# 46793 update to NRC (Crouch) at 1842 CDT. At 1820 CDT a determination was made that offsite emergency notification sirens did not meet the minimum required number operable. Seventy of the one hundred sirens are required to be operable and twelve of the sirens are operable at this time. This condition is reportable IAW 10CFR50.72(b)(3)(xiii) - Any event that results in a major loss of emergency assessment capability, offsite response capability, or offsite communications capability (e.g., significant portion of control room indication, emergency notification system, or offsite notification system) (8-hour notification). This was reported in an EN# 46793 update to NRC (Crouch) at 2053 CDT. Following auto-start of the diesel driven fire pump, subsequent to the loss of offsite 500kV power system, approximately one quart of oil leaked from the drain plug in the diesel engine of the pump to the plant cold water channel (waters of the United States). This oil produced a "sheen" on the water (confirmed at 1950 CDT) that required a response to the National Response Center IAW 40CFR112.7(a)(4). This condition was reported to the National Response Center at 2055 CDT and assigned spill number 974232. In addition, IAW the BFNP NPDES (National Pollution Discharge Elimination System) permit, the State of Alabama was notified at 2100 CDT of the spill and subsequent notification of the National Response Center. The notification of these outside agencies is reportable IAW 10CFR50.72(b)(2)(xi) - Any event or situation, related to the health and safety of the public or onsite personnel, or protection of the environment, for which a news release is planned or notification of other government agencies has been or will be made. Such an event may include an onsite fatality or inadvertent release of radioactive contaminated materials (4 hour notification). This was reported in an EN# 46793 update to NRC (Crouch) at 2203 CDT. At 2120 CDT, Unit 1 received a low reactor water level scram due to reactor water level lowering to +2 inches following sluggish RCIC response at low reactor pressure. At the time of this event RCIC and CRD were injecting to the vessel and the reactor level band specified was +2 to +51 inches. A valid Containment Isolation signal was received and groups 2, 3, 6 and 8 isolated as expected. Water level was immediately restored to within the specified band (RCIC). This condition is reportable IAW10CFR 50.72(b)(3)(iv)(A) - Any event or condition that results in the valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B), except when the actuation results from and is part of a pre-planned sequence during testing or reactor operation (8-hour notification). The systems with valid actuations were RPS and Containment Isolation. The Emergency Diesel Generators were already running at the time of the event. This was reported in an EN# 46793 update to NRC (Crouch) at 2238 CDT. The NRC resident has been notified of these 1, 4 and 8 hour reports and EN#46793 updates. These conditions and notifications will be captured in the licensee's Corrective Action Program.
At 2050 CDT, on 05/02/2011, the previously declared and reported NOUE (EAL Designator 5.1U) due to loss of normal and alternate voltage to all 4kV SD Boards for greater than 15 minutes and at least two Diesel Generators supplying power to unit specific 4kV SD Boards was terminated due to the conditions requiring entry being resolved. At this time, offsite power has been restored from two 161kV sources (Athens and Trinity), all eight 4kV SD boards are being powered from offsite sources, and six of eight Emergency Diesel Generators (B, C, D, 3A, 3C, 3D) are operable and in standby readiness. Emergency Diesel Generators A and 3B are not operable but are available at this time. All three units remain shutdown, in Mode 4, pending return of the 500 kV grid system. A timeline for return of the 500 kV grid system is yet to be finalized. In addition, the previous 8-hour notification of offsite emergency sirens not meeting the minimum required is being updated to reflect current conditions. As of 1015 CDT, on 05/02/2011, repair activities have resulted in 92 of 100 sirens being in operable status, thereby meeting the minimum requirement of 70 operable. The licensee has notified the NRC Resident Inspector and the State of Alabama. Notified R2DO (Seymour), NRR EO (Nelson), IRD (Grant), DHS (Daly), and FEMA (Dennis). | High Pressure Coolant Injection Reactor Protection System Emergency Diesel Generator Main Steam Isolation Valve Primary Containment Isolation System Reactor Core Isolation Cooling Primary containment | 05000259/LER-2011-001 |