ENS 41423
ENS Event | |
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01:10 Feb 20, 2005 | |
Title | Technical Specifications Required Shutdown Due to Inoperable Auxiliary Feedwater Pumps |
Event Description | During continuing evaluation of the operability of the Auxiliary Feedwater (AFW) Pump discharge pressure switches, engineering determined that a high energy line break had the potential to affect the AFW Pump Suction line from the Condensate Storage Tank (CST) due to the inability of the discharge pressure switches to protect the AFW pumps from a loss of suction from the CST. At 1910 CST on 02/19/2005 it was determined that all three AFW Pumps were inoperable as a result of the condition discovered by engineering. Due to the high energy line break, there is the potential for damage to the CST supply line to the AFW Pumps (due to pipe whip resulting from a feedwater line circumferential break). Damage to the CST supply line may result in air entrainment in the AFW Pump supply and potential AFW pump damage following an automatic AFW Pump Start.
Technical Specification 3.4.b.7 allows AFW Pumps to be placed in "pull-out" at less than 15% power because analysis shows that there is at least 10 minutes available for an operator to manually initiate AFW flow if needed. At 2003 CST a power reduction to <15% power was initiated to restore the operability of an AFW Pump. When power is less than 15%, the Turbine Driven AFW Pump will be placed in "pull-out" and Service Water will be aligned to the suction of the Turbine Driven AFW Pump to restore Operability of the Turbine Driven AFW Pump. When operability is restored to one AFW pump, the plant will enter a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> LCO as a result of two AFW Pumps remaining out of service. Since operability of the two motor driven pumps will not be restored within the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> LCO time, plant cooldown to less than 350 deg F will continue in accordance with Technical Specification 3.4.b.6. The licensee notified the NRC Resident Inspector. |
Where | |
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Kewaunee ![]() Wisconsin (NRC Region 3) | |
Reporting | |
10 CFR 50.72(b)(2)(i), Tech Spec Required Shutdown 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor | |
Time - Person (Reporting Time:+-0.38 h-0.0158 days <br />-0.00226 weeks <br />-5.20524e-4 months <br />) | |
Opened: | Scott Cieslewicz 00:47 Feb 20, 2005 |
NRC Officer: | Mike Ripley |
Last Updated: | Feb 20, 2005 |
41423 - NRC Website
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Unit 1 | |
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Reactor critical | Critical |
Scram | No |
Before | Power Operation (100 %) |
After | Power Operation (10 %) |