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At 2225 CDT on 4/18/2010, Operations disco … At 2225 CDT on 4/18/2010, Operations discovered that the Unit 1 Turbine Building Truck Aisle Rollup Door Security Fence was closed. This fence was to be maintained open as the truck aisle is a required drainage path from the Unit 1 Turbine Building to outside in the event of flooding resulting from a High Energy Line Break (HELB). With the expanded metal mesh door (fence) closed, turbine building debris could clog the drainage path and result in a higher than calculated water level being reached for this event. As the final water level cannot be predicted, this represented an unanalyzed condition. The higher water levels would be reached at least one hour after the postulated turbine building HELB event. High water levels could result in a Loss of Safety Function for Unit 1 Emergency Diesel Generators. Auxiliary Feedwater (both units) and DC Electrical Power (both units) if water levels exceed critical heights in the associated rooms.</br>The doors (fence) were reopened at 2227 CDT. Unit 1 entered LCO 3.0.3 for this two minute period. With the doors (fence) opened, Unit 1 and 2 LCO conditions were again satisfied.</br>The Unit 2 truck aisle was in the assumed condition, and Unit 2 is in Mode 5 so loss of AFW or DC power would not result in an LCO 3.0.3 entry. Unit 2 Emergency Diesel Generators are not affected as the Unit 2 truck aisle drain path would prevent water levels from reaching critical heights.</br>The initial investigation determined that a Security Officer had closed the gate at approximately 1855 CDT on 4/18/2010.</br>The NRC Resident Inspector has been notified. A press release is not planned.</br>* * * RETRACTION AT 1454 ON 4/22/2010 FROM DARRELL LAPCINSKI TO MARK ABRAMOVITZ * * *</br>In reference to the 4/18/2010 discovery of the security fences (screen door) closed on the Unit One Turbine Building truck aisle door and the Tech Spec LCO 3.0.3 entry on Unit One, further analysis of HELB flooding scenarios in the plant configuration known to be in effect at that time has shown that the LCO 3.0.3 entry was not warranted. Engineering analysis demonstrates that water levels in the Unit One Turbine Building from a postulated worst case HELB flooding event would only have rendered the 12 Motor Driven Auxiliary Feedwater Pump inoperable. Thus TS LCO 3.7.5 Condition B would have been the only LCO action statement required to be entered. No loss of safety function existed." </br>The licensee will notify the NRC Resident Inspector.</br>Notified the R3DO (Skokowski). Inspector.
Notified the R3DO (Skokowski).
03:25:00, 19 April 2010 +
45,855 +
03:12:00, 19 April 2010 +
03:25:00, 19 April 2010 +
At 2225 CDT on 4/18/2010, Operations disco … At 2225 CDT on 4/18/2010, Operations discovered that the Unit 1 Turbine Building Truck Aisle Rollup Door Security Fence was closed. This fence was to be maintained open as the truck aisle is a required drainage path from the Unit 1 Turbine Building to outside in the event of flooding resulting from a High Energy Line Break (HELB). With the expanded metal mesh door (fence) closed, turbine building debris could clog the drainage path and result in a higher than calculated water level being reached for this event. As the final water level cannot be predicted, this represented an unanalyzed condition. The higher water levels would be reached at least one hour after the postulated turbine building HELB event. High water levels could result in a Loss of Safety Function for Unit 1 Emergency Diesel Generators. Auxiliary Feedwater (both units) and DC Electrical Power (both units) if water levels exceed critical heights in the associated rooms.</br>The doors (fence) were reopened at 2227 CDT. Unit 1 entered LCO 3.0.3 for this two minute period. With the doors (fence) opened, Unit 1 and 2 LCO conditions were again satisfied.</br>The Unit 2 truck aisle was in the assumed condition, and Unit 2 is in Mode 5 so loss of AFW or DC power would not result in an LCO 3.0.3 entry. Unit 2 Emergency Diesel Generators are not affected as the Unit 2 truck aisle drain path would prevent water levels from reaching critical heights.</br>The initial investigation determined that a Security Officer had closed the gate at approximately 1855 CDT on 4/18/2010.</br>The NRC Resident Inspector has been notified. A press release is not planned.</br>* * * RETRACTION AT 1454 ON 4/22/2010 FROM DARRELL LAPCINSKI TO MARK ABRAMOVITZ * * *</br>In reference to the 4/18/2010 discovery of the security fences (screen door) closed on the Unit One Turbine Building truck aisle door and the Tech Spec LCO 3.0.3 entry on Unit One, further analysis of HELB flooding scenarios in the plant configuration known to be in effect at that time has shown that the LCO 3.0.3 entry was not warranted. Engineering analysis demonstrates that water levels in the Unit One Turbine Building from a postulated worst case HELB flooding event would only have rendered the 12 Motor Driven Auxiliary Feedwater Pump inoperable. Thus TS LCO 3.7.5 Condition B would have been the only LCO action statement required to be entered. No loss of safety function existed." </br>The licensee will notify the NRC Resident Inspector.</br>Notified the R3DO (Skokowski). Inspector.
Notified the R3DO (Skokowski).
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100 +
00:00:00, 22 April 2010 +
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>.
02:09:50, 2 March 2018 +
03:12:00, 19 April 2010 +
true +
false +
-0.00917 d (-0.22 hours, -0.00131 weeks, -3.01356e-4 months) +
03:25:00, 19 April 2010 +
Lco 3.0.3 Entry and Loss of Safety Function Due to Loss of Turbine Building High Energy Line Break Compensatory Measure +
URL"URL" is a <a href="/Special:Types/URL" title="Special:Types/URL">type</a> and predefined property provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a> to represent URI/URL values.