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| Entered date | Event description | |
|---|---|---|
| ENS 53459 | 16 June 2018 15:56:00 | At 1121 CDT on June 16, 2018, Arkansas Nuclear One, Unit 1 (ANO-1) performed a manual reactor trip due to a Turbine Bypass valve failing open on reactor startup. At the time, ANO-1 was in Mode 2 at approximately 2 percent power. The failed Turbine Bypass valve resulted in an overcooling event and the Overcooling Emergency Operating Procedure (EOP) was entered. Main Steam Line Isolation (MSLI) automatic actuation occurred on 2 of the 4 channels of Emergency Feedwater Initiation and Control during the overcooling event in the 'B' Steam Generator. The remaining channels of MSLI were manually actuated by the control room staff from the control room. Overcooling was terminated after the closure of the Main Steam Isolation Valve (MSIV) and reactor coolant parameters were stabilized as directed by the Overcooling EOP. Additionally, Gland Sealing Steam was lost to the main turbine due to the closure of the 'B' Steam Generator MSIV and Loss of Condenser Vacuum Abnormal Operating Procedure was entered. This is a 4-hour non-emergency 10 CFR 50.72 (b)(2)(iv)(B) notification due to a Reactor Protection System actuation (scram) and an 8-hour non-emergency 10 CFR 50.72 (b)(3)(iv)(A) notification for safety system actuation." All control rods fully inserted into the core during the trip. Heat removal is via the Atmospheric Dump Control valves to atmosphere. The NRC Resident Inspector has been notified. The licensee also notified the State of Arkansas. |
| ENS 47046 | 13 July 2011 14:25:00 | Tennessee Valley Authority Paradise Fossil Plant uses an Ohmart Model SR1-A density gauge with a sealed source containing up to 1,562 milliCuries of Cesium 137. The gauge is used to monitor the density of the limestone slurry at the Unit 2 scrubber. On July 12, 2011 at 1330 (CDT) the shutter on the density gauge was determined to be not operable. It was determined that the shutter failed in the closed position when the operator received a slurry density high alarm. The shutter failure is in the closed and safe position. The gauge has been entered into the corrective action program and will be repaired by the manufacturer at a later time. There were no personnel exposures, no damages to other equipment, and no additional compensatory actions necessary since the shutter is failed closed/safe position. The licensee notified the R2DO (Freeman). |
| ENS 46008 | 15 June 2010 09:44:00 | A non-licensed employee supervisor had a confirmed positive for alcohol during a follow-up fitness-for-duty test. The employee's access to TVA nuclear plants has been terminated. Contact the Headquarters Operations Officer for additional details. |
| ENS 45405 | 2 October 2009 12:53:00 | It was discovered on October 1, 2009, that a twenty-four hour event notification was not reported. The notification was required per 10 CFR 30.50(b)(2) due to (the) inability to close a fixed gauge shutter at TVA's (Tennessee Valley Authority) Widows Creek Fossil Plant. The gauge is a Texas Nuclear unit and contains 100 mCi of Cesium-137. The gauge is used to monitor the slurry surge tank in the U7 and U8 Limestone Ball Mill Building. This gauge is used under an NRC license to TVA at the Widows Creek Fossil Plant in Stevenson, Alabama. The shutter failure discovery was made during a routine shutter check on August 4, 2009. Corrective actions were taken to repair the shutter and the shutter check was successfully completed on August 17, 2009. No personnel radiation exposure was received. These corrective actions were reported in the Corrective Action Program. |
| ENS 44752 | 5 January 2009 14:23:00 | A non-licensed contract employee was discovered to be in possession of an illegal substance inside the Unit 2 side of the common protected area following a for cause investigation. The contract employee was working in the construction of Unit 2. The contract employee's badge and access to the plant has been revoked. Contact the Headquarters Operations Officer for additional details. The licensee has notified both the Unit 1 and Unit 2 NRC Resident Inspectors. |
| ENS 44721 | 15 December 2008 15:40:00 | A non-licensed employee supervisor had a confirmed positive for illegal drugs during a random fitness-for-duty test. The employee's access to the plant has been terminated. Contact the Headquarters Operations Officer for additional details. The licensee has notified the NRC Resident Inspector. |
| ENS 44382 | 4 August 2008 13:14:00 | A non-licensed contract employee supervisor had a confirmed positive for alcohol during a random fitness-for-duty test. The contract employee's access to the plant has been terminated. Contact the Headquarters Operations Officer for additional details. The licensee has notified the NRC Resident Inspector. |