ENS Event | |
|---|---|
18:30 Jul 22, 2015 | |
| Title | Degraded Condition Due to Reactor Coolant System Leak |
| Event Description | On July 8, 2015, Fort Calhoun Station was in Mode 1, 100% when personnel identified an increase in the Reactor Coolant System unidentified leakage rate. As a result, personnel performed a containment entry and identified the source coming from the Reactor Coolant Pump 3A seal area. Based on this observation, a monitoring plan was established and on July 20, 2015 the leak rate exceeded the pre-establish leak limit and operators manually shutdown the reactor. On July 22, 2015, at approximately 1330 CDT, personnel identified the source of the seal leak as a crack on the middle seal inlet line, which is part of the reactor coolant system boundary. Maintenance personnel have since repaired the seal line and it has passed post-maintenance testing.
The 8-hour verbal report is being made post event due to additional review of the leakage condition identifying the leakage constituted a degraded condition due to be material defects in the primary coolant system. The leak rate was between 1 and 2 gpm. The licensee 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:+119.52 h4.98 days <br />0.711 weeks <br />0.164 months <br />) | |
| Opened: | Julie Bissen 18:01 Jul 27, 2015 |
| NRC Officer: | John Shoemaker |
| Last Updated: | Jul 27, 2015 |
| 51270 - NRC Website
Loading map... | |
Unit 1 | |
|---|---|
| Reactor critical | Not Critical |
| Scram | No |
| Before | Hot Shutdown (0 %) |
| After | Hot 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 | |