ENS Event | |
|---|---|
20:05 Feb 20, 2008 | |
| Title | Rhr Service Water System Declared Inoperable Due to Inability to Meet Fsar Requirement |
| Event Description | At 1505 EST, it was determined by an engineering analysis that a leak on a 3/4 inch vent line of the Residual Heat Removal Service Water (RHRSW) System common discharge line would prevent continuous operation of the system for 30 days as required by the Unit 2 FSAR.
Specifically, if the line were to completely shear, the resulting leak would have exceeded the capacity of the building sumps and over a prolonged period of operation would have resulted in the excessive water levels in the Reactor Building Torus room area. In order to mitigate the condition, supplemental pumping capacity would be needed in the building sumps or the RHRSW system would have to be temporarily secured. The RHRSW system has been tagged out for repair of the line. The appropriate 8-hour RAS in Tech Spec has been entered. The line will be repaired and the system returned to service. The licensee identified the crack in the socket weld during a system walkdown and anticipates completion of repairs in approximately 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. The licensee informed the NRC Resident Inspector.
At 2120 EST on 02/20/08 the RHR SW System was declared OPERABLE after completion of repairs and testing. The failure of the socket weld at 2E11-FV001 is preliminarily attributed to fatigue cracking caused by vibration. A root cause investigation is ongoing. A system walkdown did not identify any additional deficiencies. The licensee informed the NRC Resident Inspector. Notified R2DO(Robert Haag). |
| Where | |
|---|---|
Hatch  Georgia (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat | |
| Time - Person (Reporting Time:+-3.58 h-0.149 days <br />-0.0213 weeks <br />-0.0049 months <br />) | |
| Opened: | Tony Spring 16:30 Feb 20, 2008 |
| NRC Officer: | Steve Sandin |
| Last Updated: | Feb 20, 2008 |
| 43996 - NRC Website
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Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 439962008-02-20T20:05:00020 February 2008 20:05:00
[Table view]10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat Rhr Service Water System Declared Inoperable Due to Inability to Meet Fsar Requirement ENS 435032007-07-18T16:20:00018 July 2007 16:20:00 10 CFR 50.72(b)(3)(v)(A), Loss of Safety Function - Shutdown the Reactor, 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(ii)(B), Unanalyzed Condition, 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material Unanalyzed Condition - Vent Space Less than Design Basis 2008-02-20T20:05:00 | |