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This report documents a condition in which … This report documents a condition in which WBN (Watts Bar Nuclear) Unit 1 met the criteria to declare a NOUE (Notification of Unusual Event) based on RCS (Reactor Coolant System) unidentified leakage. Prior to declaration, the event was terminated thus no declaration was made. This event is reportable within one hour as an acceptable alternative to reporting in accordance with 10CFR50.72(a)(1)(i) - declaration of any of the emergency classes specified in the licensees approved emergency plan.</br>During tagout installation in support of planned maintenance on the cation bed flush valve (1-FLV-62-921) in the CVCS/Letdown system, isolation boundary valve leakage of approximately 80 gpm was present for approximately three minutes. The leakage was terminated by reclosing opened vent (1-VTV-62-917) and drain valves (1-DRV-62-920). Cation Bed Inlet (l-ISV-62-915) and Outlet (1-ISV-62-916) and all other boundary valve isolations were verified to be in the correct, closed position per the tagout instructions. This RCS leakage was directed to the Tritiated Drain Collector Tank, thus all leakage was contained within plant systems and no radiological releases resulted. A work order will be initiated to troubleshoot and repair the faulty isolation valve.</br>This amount of leakage is in excess of the amount specified in WBN Emergency Plans for declaration of an NOUE based on >10 gpm unidentified leakage per EAL 2.5. Prior to declaration, the event was terminated, thus no declaration was made.</br>The State of Tennessee and the NRC Resident Inspector has been notified.</br>* * * RETRACTION ON 9/15/2009 AT 1113 FROM WES DANIEL TO MARK ABRAMOVITZ * * *</br>Event Notice 45331 reported a condition in which WBN Unit 1 conservatively determined it met the criteria to declare a NOUE based on RCS unidentified leakage. Prior to declaration, the event was terminated thus no declaration was made. </br>Based upon further review and discussion with others in the industry, the NOUE criterion cited, EAL 2.5, applies to specific sources of excessive RCS leakage. The source of the leakage discussed in the event has been confirmed as CVCS leakage, not RCS leakage. An action to clarify the basis and scope of this EAL is being pursued within TVA's Corrective Action Program. Therefore, Event Notice 45331 is being retracted.</br>The NRC resident has been notified.</br>Notified the R2DO (Blamey).as been notified.
Notified the R2DO (Blamey).
01:20:00, 8 September 2009 +
45,331 +
22:02:00, 7 September 2009 +
01:20:00, 8 September 2009 +
This report documents a condition in which … This report documents a condition in which WBN (Watts Bar Nuclear) Unit 1 met the criteria to declare a NOUE (Notification of Unusual Event) based on RCS (Reactor Coolant System) unidentified leakage. Prior to declaration, the event was terminated thus no declaration was made. This event is reportable within one hour as an acceptable alternative to reporting in accordance with 10CFR50.72(a)(1)(i) - declaration of any of the emergency classes specified in the licensees approved emergency plan.</br>During tagout installation in support of planned maintenance on the cation bed flush valve (1-FLV-62-921) in the CVCS/Letdown system, isolation boundary valve leakage of approximately 80 gpm was present for approximately three minutes. The leakage was terminated by reclosing opened vent (1-VTV-62-917) and drain valves (1-DRV-62-920). Cation Bed Inlet (l-ISV-62-915) and Outlet (1-ISV-62-916) and all other boundary valve isolations were verified to be in the correct, closed position per the tagout instructions. This RCS leakage was directed to the Tritiated Drain Collector Tank, thus all leakage was contained within plant systems and no radiological releases resulted. A work order will be initiated to troubleshoot and repair the faulty isolation valve.</br>This amount of leakage is in excess of the amount specified in WBN Emergency Plans for declaration of an NOUE based on >10 gpm unidentified leakage per EAL 2.5. Prior to declaration, the event was terminated, thus no declaration was made.</br>The State of Tennessee and the NRC Resident Inspector has been notified.</br>* * * RETRACTION ON 9/15/2009 AT 1113 FROM WES DANIEL TO MARK ABRAMOVITZ * * *</br>Event Notice 45331 reported a condition in which WBN Unit 1 conservatively determined it met the criteria to declare a NOUE based on RCS unidentified leakage. Prior to declaration, the event was terminated thus no declaration was made. </br>Based upon further review and discussion with others in the industry, the NOUE criterion cited, EAL 2.5, applies to specific sources of excessive RCS leakage. The source of the leakage discussed in the event has been confirmed as CVCS leakage, not RCS leakage. An action to clarify the basis and scope of this EAL is being pursued within TVA's Corrective Action Program. Therefore, Event Notice 45331 is being retracted.</br>The NRC resident has been notified.</br>Notified the R2DO (Blamey).as been notified.
Notified the R2DO (Blamey).
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100 +
00:00:00, 15 September 2009 +
Modification date"Modification date" is a predefined property that corresponds to the date of the last modification of a subject and is provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
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