ENS Event | |
|---|---|
15:00 Jul 17, 2012 | |
| Title | Degraded Charging Line Socket Welds Based on Thermal Fatigue Analysis |
| Event Description | Results of a thermal fatigue analysis on the Chemical and Volume Control System (CVCS) charging line concluded that the socket weld fittings above the RCS piping cannot be qualified.
As an interim action, shut down cooling purification has been secured and charging has been isolated to the RCS. The plant is shutdown and in Mode 5 with the reactor vessel head removed, so RCS is not intact and not required to be for current plant conditions. This report is being made in accordance with 10CFR50.72(b)(3)(ii)(A) for a degraded condition. The licensee has notified the NRC Resident Inspector. |
| Where | |
|---|---|
Fort Calhoun  Nebraska (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded | |
| Time - Person (Reporting Time:+0.07 h0.00292 days <br />4.166667e-4 weeks <br />9.5886e-5 months <br />) | |
| Opened: | Scott Moeck 15:04 Jul 17, 2012 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Jul 17, 2012 |
| 48111 - NRC Website
Loading map... | |
Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Cold Shutdown (0 %) |
| After | Cold Shutdown (0 %) |
WEEKMONTHYEARENS 512702015-07-22T18:30:00022 July 2015 18:30:00
[Table view]10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Degraded Condition Due to Reactor Coolant System Leak ENS 497102014-01-10T05:17:00010 January 2014 05:17:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Degraded Fittings Connected to Containment Penetration ENS 494522013-10-18T18:28:00018 October 2013 18:28:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Potential for High Energy Line Break on Letdown System Outside Containment ENS 481112012-07-17T15:00:00017 July 2012 15:00:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Degraded Charging Line Socket Welds Based on Thermal Fatigue Analysis ENS 479532012-05-23T21:00:00023 May 2012 21:00:00 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Crack Identified in Pressurizer Heater ENS 457242010-02-24T17:40:00024 February 2010 17:40:00 10 CFR 50.72(b)(3)(v)(B), Loss of Safety Function - Remove Residual Heat, 10 CFR 50.72(b)(3)(ii)(A), Seriously Degraded Auxiliary Feedwater Pumps May Experience Runout at Low Steam Pressures 2015-07-22T18:30:00 | |