ENS 42437
ENS Event | |
|---|---|
21:08 Mar 21, 2006 | |
| Title | Degraded Condition - Indication on Primary Coolant System Pressure Boundary Weld |
| Event Description | On March 18, 2006, with the Davis-Besse Nuclear Power Station in Mode 6 (Refueling), an axial indication was discovered on the Reactor Coolant Pump 1-1 Cold Leg Drain Line Nozzle to Elbow Weld. At the time of discovery, the indication was determined to be at least 0.25 inches in length, but the through-wall depth of this indication could not be determined.
Further evaluation of this indication is in progress by an offsite engineering organization. Based upon preliminary evaluation, it has been determined that this indication cannot be found acceptable under ASME Section XI. 10CFR50.72(b)(3)(ii)(A) requires reporting of any event or condition that results in the condition of the nuclear power plant, including its principal safety barriers, being seriously degraded. NUREG-1022, 'Event Reporting Guidelines - 10CFR50.72 and 10CFR50.73' lists as an example of such degradation 'Welding or material defects in the primary coolant system which cannot be found acceptable under ASME Section XI, IWB-3600, 'Analytical Evaluation of Flaws' or ASME Section XI, Table IWB-3410-1, 'Acceptance Standards.' Based upon the preliminary evaluation by the offsite engineering organization, the axial indication is being conservatively reported per 10CFR50.72(b)(3)(ii)(A) as a serious degradation of a principle safety barrier. The plant is currently defueled, and plans are underway to determine the necessary repair [to] this indication. The licensee will notify the NRC Resident Inspector. |
| Where | |
|---|---|
Davis Besse  Ohio (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | |
| LER: | 05000346/LER-2006-002 |
| Time - Person (Reporting Time:+-3.8 h-0.158 days <br />-0.0226 weeks <br />-0.00521 months <br />) | |
| Opened: | Robert Lakis 17:20 Mar 21, 2006 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Mar 21, 2006 |
| 42437 - NRC Website
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WEEKMONTHYEARENS 518372016-03-30T21:15:00030 March 2016 21:15:00
[Table view]10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Degraded Condition Due to Discovery of Pressure Boundary Leakage ENS 491632013-07-01T15:03:0001 July 2013 15:03:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Degraded Condition Due to Rcp Seal Line Pressure Boundary Leakage ENS 480002012-06-06T23:56:0006 June 2012 23:56:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Degraded Condition Due to Discovery of Pressure Boundary Leakage ENS 457642010-03-13T02:43:00013 March 2010 02:43:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Control Rod Drive Mechanism Nozzle Indications ENS 438802008-01-04T07:50:0004 January 2008 07:50:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Pressure Boundary Leakage Discovered During Refueling ENS 424372006-03-21T21:08:00021 March 2006 21:08:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Degraded Condition - Indication on Primary Coolant System Pressure Boundary Weld 2016-03-30T21:15:00 | |