ENS 47534
ENS Event | |
|---|---|
21:44 Dec 19, 2011 | |
| Title | Offsite Notification Due to Tritium Levels Exceeding Threshold for Drinking Water |
| Event Description | 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. |
| Where | |
|---|---|
Sequoyah  Tennessee (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | |
| Time - Person (Reporting Time:+-4.32 h-0.18 days <br />-0.0257 weeks <br />-0.00592 months <br />) | |
| Opened: | Tim Rieger 17:25 Dec 19, 2011 |
| NRC Officer: | John Knoke |
| Last Updated: | Dec 19, 2011 |
| 47534 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 565922023-06-27T12:31:00027 June 2023 12:31:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release Offsite Notification ENS 549182020-09-28T15:43:00028 September 2020 15:43:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release | Offsite Notification - Oil Spill ENS 537542018-11-26T05:00:00026 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 ENS 536802018-10-21T04:00:00021 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 ENS 532702018-03-19T04:30:00019 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 ENS 524262016-12-13T19:10:00013 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 ENS 507572015-01-23T16:50:00023 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 ENS 505812014-10-30T16:20:00030 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 ENS 497382014-01-17T19:00:00017 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 ENS 480742012-07-06T14:12:0006 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 ENS 479592012-05-24T19:41:00024 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 ENS 479222012-05-14T14:24:00014 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 ENS 475342011-12-19T21:44:00019 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 ENS 472562011-09-12T17:05:00012 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) ENS 470452011-07-13T04:23:00013 July 2011 04:23:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release Overflow of Condenser Circulating Water ENS 467902011-04-27T14:30:00027 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 ENS 461952010-08-21T19:09:00021 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 ENS 456682010-01-31T15:42:00031 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 ENS 453952009-09-30T19:21:00030 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 ENS 453532009-09-16T16:20:00016 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 ENS 451722009-06-29T15:34:00029 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 ENS 450642009-05-13T19:05:00013 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 ENS 406552004-04-08T12:45:0008 April 2004 12:45:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release Off Site Notification 2023-06-27T12:31:00 [Table view] | |