ENS Event | |
|---|---|
06:00 Nov 3, 2009 | |
| Title | Instrument Line Determined to Have Inadequate Structural Support |
| Event Description | At 1700 on 12/10/09, an operability evaluation determined that an instrument line within the primary containment did not have adequate structural support during the previous operating cycle. The evaluation determined that the instrument line would have failed during a Safe Shutdown Earthquake (SSE). This would have resulted in reactor coolant leakage within the primary containment that could not be isolated.
The condition was identified and repaired during the recent refueling outage and full qualification and operability was restored prior to return to service. The condition was discovered on November 3, 2009 during the Unit 2 refueling outage. The operability determination was completed on December 10, 2009. It is unknown at this time if the condition exists in Unit 3 due to inaccessibility of the drywell during power operations. |
| Where | |
|---|---|
Dresden  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | |
| Time - Person (Reporting Time:+903.48 h37.645 days <br />5.378 weeks <br />1.238 months <br />) | |
| Opened: | Mark Hanneman 21:29 Dec 10, 2009 |
| NRC Officer: | Howie Crouch |
| Last Updated: | Dec 10, 2009 |
| 45561 - NRC Website
Loading map... | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 530482017-11-01T17:25:0001 November 2017 17:25:00
[Table view]10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Unit 2 Failed Llrt Surveillance Test Due to Excessive Leakage ENS 495852013-11-26T20:00:00026 November 2013 20:00:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Leakage Discovered on Electromatic Relief Valve During Hydrostatic Testing ENS 495352013-11-14T09:00:00014 November 2013 09:00:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Primary Containment Isolation Valve Leak Test Failure ENS 454752009-11-03T11:09:0003 November 2009 11:09:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Degraded Condition Due to Weld Issue ENS 455612009-11-03T06:00:0003 November 2009 06:00:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Instrument Line Determined to Have Inadequate Structural Support 2017-11-01T17:25:00 | |