ENS Event | |
|---|---|
20:12 May 4, 2010 | |
| Title | Discovery of After-The- Fact Emergency Condition - Unusual Event Due to Rcs Lineup |
| Event Description | On 5/4/2010 at 15:12 CDT when attempting to flush CH-1A charging pump, a loss of charging flow occurred.
CH-193 discharge valve for CH-1A charging pump was found to be open. This resulted in a flow path to the auxiliary building sump tank when CH-356 charging pump CH-1A discharge drain valve to waste disposal system was opened. This resulted in an approximately 38 gpm leak from the reactor coolant system via letdown to waste. This leak was isolated within 1 minute. The site entered and exited the conditions for NOUE before the shift manager was able to make an E-plan call. There are currently no emergency conditions on site and an NOUE was never declared. The reactor continued to operate at 100% power throughout the event. The cause of this event is believed to be a valve line-up error. The NRC Resident Inspector has been notified. The site plans to notify the State of Nebraska. No other notifications are planned.
The declaration of Unusual Event SU 5 EAL 2, RCS leakage, on 5/4/10 is being retracted, because the declaration was inaccurate. The leak was an intersystem leak of the CVCS, not RCS leakage, and the leak was isolated as previously noted. Therefore, the leakage did not meet the initiating condition for the EAL. The licensee has notified the NRC Resident Inspector and plans to notify the State of Nebraska. Notified R4DO (Farnholtz), NRR EO (Quay), and IRD (McDermott). |
| Where | |
|---|---|
Fort Calhoun  Nebraska (NRC Region 4) | |
| Reporting | |
| Other Unspec Reqmnt | |
| Time - Person (Reporting Time:+-3.27 h-0.136 days <br />-0.0195 weeks <br />-0.00448 months <br />) | |
| Opened: | Nathan Seid 16:56 May 4, 2010 |
| NRC Officer: | Eric Simpson |
| Last Updated: | May 5, 2010 |
| 45898 - NRC Website
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Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |
WEEKMONTHYEARENS 521882016-08-17T23:26:00017 August 2016 23:26:00
[Table view]Other Unspec Reqmnt Offsite Power Source Below the Operability Limit ENS 458982010-05-04T20:12:0004 May 2010 20:12:00 Other Unspec Reqmnt Discovery of After-The- Fact Emergency Condition - Unusual Event Due to Rcs Lineup ENS 436782007-10-01T18:15:0001 October 2007 18:15:00 Other Unspec Reqmnt Replacing the Emergency Response Facility Computer System ENS 435822007-08-21T02:03:00021 August 2007 02:03:00 Other Unspec Reqmnt Inoperable House Service Transformers ENS 408852004-07-20T23:18:00020 July 2004 23:18:00 Other Unspec Reqmnt 4-Hour Notification Required by Technical Specifications 2016-08-17T23:26:00 | |