Semantic search
| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 56592 | 27 June 2023 12:31:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification | The following information was provided by the licensee via phone and email: At 0831 (EDT) on June 27, 2023, Sequoyah Nuclear Plant reported an oil discharge into the plant intake located on the Tennessee River to the (Department of Transportation) National Response Center (report number 1371356). The source of oil was from a broken hydraulic hose from equipment in use on the intake. This oil spill is minor and did not exceed any NRC regulations or reporting criteria. This notification is being made solely as a four-hour, non-emergency notification for a Notification of Other Government Agency. This event is reportable in accordance with 10 CFR 50.72(b)(2)(xi). There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. | ||
| ENS 54918 | 28 September 2020 15:43:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification - Oil Spill | On 9/28/20 at 1143 EDT, a notification to the National Response Center was made after discovery of a visible oil sheen on the waters of the U.S. (Sequoyah's side of the intake forebay skimmer wall at the Essential Raw Cooling Water (ERCW) building). The source was an oil bucket that overflowed with rain at the ERCW pumping station. Efforts are in progress to eliminate all other potential sources of oil at the station that could be released to the environment. Estimate of volume spilled is less than one quart. The following agencies have also been notified: - EPA Region 4 - Tennessee Emergency Management Agency (TEMA) - Tennessee Department of Environment and Conservation (TDEC). Cleanup is in progress. Measures to prevent recurrence are being taken. This is a four-hour notification, non-emergency for a notification of other government agency. This event is reportable in accordance with 10 CFR 50.72(b)(2)(xi). The NRC Resident Inspector has been notified. | ||
| ENS 53754 | 26 November 2018 05:00:00 | 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 for Excessive Smoke in Containment | At 0816 EST, a Notification of Unusual Event was declared for Unit 2 under Emergency Action Level H.U.4 for excessive smoke in the lower level of containment with a heat signal. Onsite fire brigade is responding to the event. A command post is established. Offsite support is requested by the fire brigade. No flames have been observed as of this report. The NRC Resident Inspector and State and Local government agencies will be notified. Notified DHS SWO, FEMA Operations Center, DHS NICC, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email).
At 1036 EST, Sequoyah Nuclear Station Unit 2 terminated the Notice of Unusual Event. The licensee determined that the source of the smoke in containment was oil on the pressurizer beneath the insulation, that heated up during plant heatup. The licensee did not see visible flame during the event. The licensee is still working to determine if there was any damage to the pressurizer. The licensee will notify the NRC Resident Inspector. Notified R2DO (Rose), R2RA (Haney), NRR (Nieh), IRD MOC (Gott), DHS SWO, FEMA Operations Center, DHS NICC, FEMA NWC (email), DHS Nuclear SSA (email), and FEMA NRCC SASC (email).
Following declaration of the Notification of Unusual Event, TVA media relations communicated with the local media regarding the event. The licensee has notified the NRC Resident Inspector. Notified R2DO (Rose).
At 1036 EDT, Sequoyah Nuclear Plant (SQN) terminated the Notification Of Unusual Event (NOUE) due to initial report of heat and smoke in Unit 2 Lower Containment. At 1000 EDT, it was determined that no fire had occurred. Due to difficulty of access to some of the areas being searched, the source could not be identified prior to 1000 EDT. No visible flame (heat or light) was observed. The source of the smoke was determined to be residual oil from a hydraulic tool oil in contact with pressurizer piping. The pressurizer piping was being heated up to support Unit 2 start-up following U2R22 refueling outage. Once the residual oil dissipated, the smoke stopped. It has been concluded that no fire or emergency condition existed. Unit 2 is currently in Mode 5, maintaining reactor coolant temperature 160F-170F and pressure 325psig-350psig with 2A Residual Heat Removal (RHR) system in service in accordance with U2R22 refueling outage plan. The licensee has notified the NRC Resident Inspector. Notified R2DO (Rose).
Sequoyah Nuclear Plant (SQN) is retracting this notification based on the following additional information not available at the time of the notification: Following a full Reactor Building inspection, it was concluded that a fire did not exist. The source of the smoke originally reported was later determined to be residual oil from a hydraulic tool in contact with pressurizer piping. Once the residual oil dissipated, the smoke stopped. The source of heat originally reported was normal heated conditions associated with the pressurizer commensurate with plant conditions. SQN reported initially based on the available information at the time and to ensure timeliness with emergency declaration and reporting notification requirements. The licensee has notified the NRC Resident Inspector. Notified R2DO (Shaeffer). | Residual Heat Removal | |
| ENS 53680 | 21 October 2018 04:00:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Death of Employee on Site | This notification is being made due to the death of an employee on-site. A Security Officer was found unresponsive on the Turbine Building Moisture Separator Re-heater deck on the Unit 1 side. Upon arrival of Fire Operations and on-site medical the individual had suffered an apparent heart attack. Hamilton County Emergency Medical Services will be transferring the individual to the medical examiner's office. The on-site NRC Senior Resident Inspector has been notified. The licensee believes this event may receive media attention and a press release could be issued. | ||
| ENS 53270 | 19 March 2018 04:30:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Two Contractors Injured by Arc Flash | On 3/16/2018 at approximately 1630 EST, an industrial safety accident occurred at Sequoyah Nuclear Plant that involved an Arc Flash injury of two contract employees. While performing work near a non safety related 6.9kV electrical bus, an arc occurred injuring the two employees. Both personnel were transported to an offsite medical facility for treatment. Neither were contaminated. The cause of the arc flash is not understood at this time, an accident investigation has been initiated by TVA. The SQN (Sequoyah Nuclear) NRC Senior Resident Inspector has been notified. No safety related systems required to establish or maintain safe shutdown were affected. Both Unit 1 and 2 remain at 100 (percent) power. TVA has received and responded to media inquiries concerning this event. As a result, this event is considered reportable under 10CFR50.72(b)(2)(xi). | ||
| ENS 52426 | 13 December 2016 19:10:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification - Water Containing Tritium Spilled Into Storm Drain | On 12/13/16 at 1410 (EST), the following voluntary communication was made to the State of Tennessee in accordance with Tennessee Valley Authority's (TVA) guidance for communicating inadvertent radiological spills/leaks that are below regulatory reporting requirements to outside agencies and in alignment with NEI 07-07, 'Industry Ground Water Protection Initiative'. On 12/12/16, Sequoyah Nuclear Plant determined that a spill of greater than 100 gallons (approximately 3000 gallons) of condensate storage tank water with tritium levels of 1560 pCi/L (picocuries per liter) was spilled to a yard drain. The spill occurred on 12/5/16, during the filling of the Unit 1 #4 steam generator when a hose connection on a temporary fill skid failed. No elevated tritium levels have been detected at the Sequoyah Yard Drainage Pond before or after the event. This is reported in accordance with 10CFR50.72(b)(2)(xi), the required reportable threshold for tritium is 20,000 pCi/L. The licensee will notify the NRC Resident Inspector. | Steam Generator | |
| ENS 50757 | 23 January 2015 16:50:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notifications Due to Oil Sheen on Intake Bay | On 1/23/2015 at 1150 EST, an oil sheen was verified to be in the waters of the U.S. (Sequoyah's Intake Forebay). At 1221 (EST), a notification to the National Response Center (report #1106407) was made as a result of the oil sheen (< 1 pint total). The source of the oil is from temporary connections in support of maintenance. Cleanup efforts are in progress. The following additional agencies have also been notified: EPA Region 4, Tennessee Department of Environment and Conservation (TDEC), and Tennessee Emergency Management Agency (TEMA). The licensee also notified the Hamilton County Emergency Management Agency and the NRC Resident Inspector. | ||
| ENS 50581 | 30 October 2014 16:20:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Regarding Boone Dam Stability Issues | On October 30, 2014, at 1100 EDT, TVA conducted a briefing for government officials and other stakeholders regarding the decision to accelerate the Boone Reservoir annual drawdown after discovery of a sink hole near the base of the embankment and a small amount of water and sediment found seeping from the river below the dam. TVA is continuously monitoring the dam and conducting an investigation to determine the source of the water seepage. The dam is located upstream of all three TVA nuclear sites. There are currently no nuclear plant operability or safety issues, and TVA is assessing the impacts on the plant licensing bases The licensee has notified the NRC Resident Inspector. | ||
| ENS 49738 | 17 January 2014 19:00:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Fuel Oil Found During Core Drilling | On January 17, 2014, at 1400 EST Sequoyah (SQN) notified the Tennessee Department of Environment and Conservation (TDEC) of a condition that was identified on December 4, 2013, while conducting core samples. The core drilling contractor detected a petroleum odor, notified the SQN Environmental Group who observed the core drilling and confirmed a slight petroleum odor from a core boring in which water was detected at approximately 41 feet below the ground surface. At that time, as a result of the type of core drilling that was conducted, TVA could not verify if there were petroleum products in the groundwater. SQN obtained geoprobe boring samples to determine the extent and the depth of the petroleum. Petroleum product was detected in the soil between 30 and 35 feet in depth. This condition has been determined to be associated with a legacy diesel fuel oil leak at SQN in the 1990's and was previously reported. SQN previously completed a remediation project from 1992 - 2010, with oversight from TDEC. The petroleum product appears to be isolated at approximately 30 to 35 feet in depth, is in a perched water table not utilized for drinking water, and appears to be isolated to the diesel building area. To verify the petroleum product is isolated; TVA is conducting additional geoprobe boring to help define the limited area impacted by the legacy diesel fuel oil leak. The Sequoyah NRC Resident Inspectors have been notified. | ||
| ENS 48074 | 6 July 2012 14:12:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Loss of 21 Offsite Sirens Due to Inclement Weather | At 1012 EDT on July 6, 2012, Tennessee Valley Authority (TVA) notified Tennessee Emergency Management Agency (TEMA) due to a loss of twenty-one (21) offsite sirens. Siren outages are believed to be from power supply failures caused by high winds resulting in downed trees last night. Efforts are in place to restore offsite sirens to service. A loss of 21 of the 108 offsite sirens does not constitute a significant degradation in the Alert and Notification System. (A loss of 32 sirens constitutes a significant degradation.) Both Sequoyah units remain at 100 percent power. NRC Resident Inspector has been notified. | ||
| ENS 47959 | 24 May 2012 19:41:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Oil Sheen on the River | On 5/24/2012 at 1541 EDT, a notification to the National Response Center was made after the discovery of a visible oil sheen on waters of the U.S. (the Tennessee River side of Sequoyah's intake forebay skimmer wall). The source of the oil appears to be a tipped or overflowing catchpan located in the Essential Raw Cooling Water (ERCW) pumping station. All catchpans in the pumping station have been emptied to eliminate them as immediate potential source of oil released to the environment. The following agencies have also been notified: EPA Region 4, and the Tennessee Emergency Management Agency (TEMA). The Tennessee Department of Environment and Conservation (TDEC) will be notified. Cleanup is in progress. Measures to prevent recurrence are being taken. The NRC Resident Inspector will be notified. | ||
| ENS 47922 | 14 May 2012 14:24:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Oil Sheen Observed on Diffuser Pond | On 05/14/2012 at 1024 EDT, a notification to the National Response Center was made as a result of an oil sheen on waters of the U.S. (Sequoyah's Diffuser pond). The discharge from an onsite pond was isolated stopping what appears to be the source of all to the diffuser pond. The source of leakage is still under investigation. The following additional agencies have also been notified: EPA Region 4, Tennessee Department of Environment and Conservation (TDEC), and Tennessee Emergency Management Agency (TEMA). Oil is maintained onsite, (and) no oil has been discharged to the river. Cleanup is in progress. The licensee notified the NRC Resident Inspector. Notified DOE (Turner), EPA (Post), USDA (Beverly), HHS (Emerson), and FEMA (Casto). | ||
| ENS 47534 | 19 December 2011 21:44:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Tritium Levels Exceeding Threshold for Drinking Water | At 1644 EST, on 12/19/11, TVA's Sequoyah Nuclear Plant made voluntary offsite notifications to the Tennessee Radiological Health Department Director and the Tennessee Department of Environmental Conservation - Senior Director Water Programs, to inform them of the following: On October 31, 2011, Sequoyah proactively installed two new groundwater monitoring wells in an area known to have contained previously reported releases of tritium in an effort to further characterize and validate the scope of the plume. These releases were reported in 2006 as part of NEI's (Nuclear Energy Institute) groundwater initiative. On December 16, 2011, elevated levels of tritium were identified in water samples taken from one new onsite monitoring well. The tritium levels were confirmed to be greater than 20,000 pCi/L which is the threshold for drinking water. No groundwater monitoring wells are used for drinking or irrigation purposes onsite. The highest level sampled was 22,760 pCi/L. Samples taken in the discharge channel located 30 yards from this groundwater monitoring well confirmed no detectable tritium. Refueling Water Storage Tank levels are being monitored and no active leak is in progress. Samples of adjacent wells have been taken and confirmed no unexpected changes in tritium levels of these wells. Additionally, Sequoyah has sampled at the station discharge to the Tennessee River and confirmed no detectable levels in any sample. In a conservative decision making process and in accordance with the groundwater protection initiative established by the nuclear industry, Sequoyah is voluntarily communicating sample results likely attributed to a previously reported tritium spill. The plant is continuing to review the sample results to confirm this is related to the historical tritium plume. The plant will take appropriate actions as outlined in the Groundwater Tritium Action Plan, which has been initiated to address this issue. Sequoyah Nuclear Plant has had an extensive groundwater monitoring program in place since 2008. The environmental sampling program consists of sixteen groundwater wells which are periodically sampled in accordance with industry standards. The NRC Resident Inspector has been notified. The following agencies have been, or will be updated: Hamilton County, State of Tennessee, Nuclear Energy Institute and American Nuclear Insurers. Tennessee Valley Authority plans a media notification for this issue. | ||
| ENS 47256 | 12 September 2011 17:05:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification to the Tennessee Department of Environment and Conservation (Tdec) | On August 25, 2011, it was discovered that a hazardous waste drum containing x-ray fixer waste was not shipped to the permitted Hazardous Waste Storage Facility within the timeframe required by the Tennessee Department of Environment and Conservation (TDEC) regulations. The drum was shipped to the permitted Hazardous Waste Storage Facility on September 01, 2011. The written notification to TDEC was signed on September 12, 2011. The licensee informed the NRC Resident Inspector. | ||
| ENS 47045 | 13 July 2011 04:23:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Overflow of Condenser Circulating Water | At 0023 on 07/13/2011, a notification to an outside state agency, Tennessee Department of Environment and Conservation (TDEC), was made due to an overflow of Condenser Circulating Water from the northwest corner of the diffuser pond through a heavily vegetated area into a slough adjacent to the Sequoyah Training Center. Condenser Circulating Water is also discharging to the river via storm water outfall 14 near the cooling towers as well as the normal diffuser pond discharge at outfall 101. At approximately 1545 on 07/12/2011, one of the two diffuser gates at Sequoyah failed and shut off the west diffuser pipe. The other diffuser remained open throughout the event. Plant personnel made several attempts to raise the diffuser gate utilizing divers and cranes. When it was determined the crane could not lift the diffuser gate, both units reduced power to 85% and one (1) Condenser Circulating Water pump for each unit, two (2) pumps total, were removed from service. Diffuser pond level is currently lowering. The NRC Resident Inspector has been informed. | ||
| ENS 46790 | 27 April 2011 14:30:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release 10 CFR 50.72(b)(3)(xiii), Loss of Emergency Preparedness | Loss of Emergency Sirens Due to Loss of Electric Power | At approximately 1030 EDT on April 27, 2011, (Sequoyah Nuclear Plant) received notification from TVAs Operations Duty Specialist that >30% of offsite sirens are not functional resulting in a 'major loss' of offsite (automatic) public notification (capabilities). The loss of offsite sirens is due to loss of electrical power caused by severe thunderstorms and high winds in the area. Thirty five sirens are not functioning (32 sirens are considered 30%). Efforts are in place to restore offsite sirens to service. At 1044 EDT on April 27, 2011, power was restored to 2 offsite sirens leaving 33 offsite sirens not functional. At 1050 EDT on April 27, 2011, TVA's Operations Duty Specialist made a notification to Tennessee Emergency Management Agency (TEMA) and Hamilton County Emergency Response. The licensee has notified the NRC Resident Inspector.
Sequoyah Nuclear Plant reported that 28 of 108 sirens are not functional (26%) which is below the 'major loss' of offsite automatic public notification capabilities threshold. The licensee has notified the Tennessee Emergency Management Agency (TEMA) and Hamilton County Emergency Response. The licensee will notify the NRC Resident Inspector. Notified R2DO (Seymour). | ||
| ENS 46195 | 21 August 2010 19:09:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Notification of State Agencies Due Leak of a Water Treatment Chemical | At 1509 on 08/21/2010, a notification to outside state agencies, Tennessee Department of Environment and Conservation (TDEC) and Tennessee Emergency Management Agency (TEMA), was made due to a Towerbrom 960 (a microbiocide) chemical leak that developed at the Essential Raw Cooling Water (ERCW) intake station. The leak occurred during scheduled chemical treatment of the ERCW system. The leak was identified at 1850 EDT on 08/20/2010 and terminated at 1955 EDT on 08/20/2010. Chemically treated ERCW containing 55 ppm total residual chlorine reached the waters of the US which is above the 0.1 ppm allowed by the plant's National Pollutant Discharge Elimination System (NPDES) permit. There have been no observable adverse effects to the environment at this time. This occurrence does not affect safety related or other plant equipment. The licensee notified the NRC Resident Inspector. | ||
| ENS 45668 | 31 January 2010 15:42:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Tema Notified of a Loss of Emergency Sirens | At 1100 EST on 1/31/10, the Sequoyah Nuclear Plant Shift Manager was made aware of notifications made to an outside government agency regarding Loss of Offsite Response Capabilities. Specifically, on 1/30/10 at 1826 EST, the Operations Duty Specialist made a Courtesy notification to the Tennessee Emergency Management Agency (TEMA) of 9 offsite sirens which had failed their polling test. This is well below the normal reporting criteria for the Emergency Plan. Subsequently, on 1/31/10 at 1042 EST, TEMA was notified that 4 of the sirens had been repaired, and only 5 sirens are still not responding to the polling test. The licensee notified the NRC Resident Inspector.
This amendment is being provided to clarify that a loss of offsite notification capabilities did not occur. At 1100 EST on 1/31/10, the Sequoyah Nuclear Plant Shift Manager was made aware of a courtesy notification made by the TVA Operations Duty Specialist to TEMA regarding loss of a small number of sirens due to inclement weather conditions. The courtesy notification was made on 1/30/10 at 1826 to inform TEMA that 9 offsite sirens had failed their polling test. A loss of 9 sirens does not constitute loss of emergency preparedness capability. This amends the original report which was made within 4 hours of the shift manager's notification. The licensee notified the NRC Resident Inspector. Notified the R2DO (Widman). | ||
| ENS 45395 | 30 September 2009 19:21:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification to Various Government Agencies | Voluntary notifications, a press release, and a webinar are being made to various government agencies and the media to provide information regarding the installation of temporary structures on top of earthen embankments of the Fort Loudoun, Tellico, Cherokee and Watts Bar dams. These dams are on the Tennessee River System. Recent upgraded flood modeling indicates that there is a possibility for overtopping to occur on these dams during a hypothetical extreme flooding scenario in the winter/spring period. As a precautionary measure, TVA is effectively raising the height of some of the dams in certain areas. These precautionary measures ensure that the TVA nuclear sites (Sequoyah, Watts Bar and Browns Ferry) will remain within their original licensing basis. Currently, Sequoyah Units 1 & 2 (DPR-77 & 79) and Browns Ferry Units 1 & 3 (DPR-33 & DPR-68) are operating at 100% power, Browns Ferry Unit 2 (DPR-52) is in Mode 4. Watts Bar Unit 1 (NPF-90) is shutdown for refueling. The licensee has notified the NRC Resident Inspectors at each of these sites. The licensee's corporate management is issuing a press release. | ||
| ENS 45353 | 16 September 2009 16:20:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Made After Discovery of an Oil Sheen | A voluntary notification to the National Response Center was made on Sept. 16, 2009 at 1220. The purpose of the notification was to inform the National Response Center of an oil sheen on a concrete pad at the inlet of the diffuser pond. The diffuser pond is classified as waters of the U.S. There was no observable oil sheen on the pond. The licensee notified the NRC Resident Inspector. | ||
| ENS 45172 | 29 June 2009 15:34:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification Due to Possible Release of Fuel Oil to the Environment | A notification to the Tennessee Department of Environment and Conservation (Chattanooga Field Office) was made at 1134 (EDT), 29 June 2009, pursuant to a failed pressure test on an underground section of diesel generator fuel oil transfer piping. This section of piping is not required for operability of the emergency diesel generators. The section of piping has been isolated. Efforts are in progress to determine if fuel oil was released to the environment. The licensee notified the NRC Resident Inspector.
During work to remediate the above concern, an offsite notification was required as described below: A notification to Hamilton County Air Pollution Control Bureau was made on July 23, 2009 at 1505 in accordance with the Site's Annual Asbestos Removal Notification . Work was being performed on buried piping when the pipe wrapping was determined to contain asbestos. Work was stopped and the work area controlled by site work documents. The licensee informed the NRC Resident Inspector. Notified R2DO (Vias). | Emergency Diesel Generator | |
| ENS 45064 | 13 May 2009 19:05:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Track Hoe Slid Into Intake Forebay | At approximately 1505 a Track Hoe clearing brush and foliage on the SQN Site berms slid into the SQN Intake Forebay. This is outside the Protected Area and does not affect Safety Related or other plant equipment. A small oil sheen was noted at the Track Hoe requiring notification of Federal and State Agencies in accordance with the Site Spill Prevention, Control and Countermeasure Plan. The containment of the oil sheen is in progress. An extraction plan is being developed by on-site personnel. The licensee notified the NRC Resident Inspector. | ||
| ENS 40655 | 8 April 2004 12:45:00 | 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Off Site Notification | On 04/08/04 at 0845 EDT, 24-hour notification was made to the Tennessee Department of Environment and Conservation (Division of Water Pollution Control) to report a potential upset of the Sequoia (SQN) National Pollution Elimination Discharge System Permit. Additional follow up evaluation is underway. On 04/07/04 at approximately 0830, a field report was received that a possible break or breach in one of the two 15 feet diameter out fall discharge diffuser pipes where the plant discharge returns to the Tennessee River. SQN inserted a 'stop log' gate in the suspected discharge path and confirmed that the #1 (South) diffuser pipe is breached. The breached portion of the pipe is underwater on the river bottom approximately 100 feet from shore. Concurrently, SQN placed both cooling towers in service with six of the available seven cooling tower lift pumps in service to minimize the potential for, or any adverse impacts from, exceeding any of the site's discharge limits. Repair actions for the pipe including initial inspections are in progress with divers on site at this time. The Site Environmental Group, in conjunction with the Tennessee Valley Authority Corporate Environmental Group, are evaluating any potential thermal non-compliance issues. The Licensee does not consider this to be a security issue. The Licensee notified the NRC Resident Inspector. |