ENS 45867: Difference between revisions
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StriderTol (talk | contribs) (Created page by program invented by Mark Hawes) |
StriderTol (talk | contribs) (Created page by program invented by StriderTol) |
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| event date = 04/19/2010 05:03 CDT | | event date = 04/19/2010 05:03 CDT | ||
| last update date = 04/22/2010 | | last update date = 04/22/2010 | ||
| title = Rps | | title = Rps and Afw Actuation Signals While Shutdown in Mode 4 | ||
| event text = Unit 2 was in Hot Shutdown [Mode 4] for a Refueling Outage. At 0503 [CDT] on April 19, 2010, a valid Lo-Lo Steam Generator level condition occurred during restoration of feedwater system testing. The feedwater test was a planned activity and included isolation of feedwater to the steam generators. During performance of the test, steam generator levels decreased and the Lo-Lo level setpoint was reached on the 2D steam generator. This generated a reactor trip signal and auxiliary feedwater system start signal. Since the Unit was in Hot Shutdown, the reactor trip breakers were already open, and the auxiliary feedwater system was already removed from service when the steam generator water level unintentionally reached the Lo-Lo level setpoint. Additionally, the open steam generator blowdown isolation valves closed as expected at the Lo-Lo steam generator level setpoint. Steam generator level was promptly restored above the Lo-Lo steam generator setpoint. There was no impact on the reactor cooldown that was concurrently in progress as part of the preparation for refueling. Initial screening of the condition determined as not reportable in accordance with 10 CFR 50.72(b)(3)(iv), however, based upon further review it has been determined the condition is reportable. | | event text = Unit 2 was in Hot Shutdown [Mode 4] for a Refueling Outage. At 0503 [CDT] on April 19, 2010, a valid Lo-Lo Steam Generator level condition occurred during restoration of feedwater system testing. The feedwater test was a planned activity and included isolation of feedwater to the steam generators. During performance of the test, steam generator levels decreased and the Lo-Lo level setpoint was reached on the 2D steam generator. This generated a reactor trip signal and auxiliary feedwater system start signal. Since the Unit was in Hot Shutdown, the reactor trip breakers were already open, and the auxiliary feedwater system was already removed from service when the steam generator water level unintentionally reached the Lo-Lo level setpoint. Additionally, the open steam generator blowdown isolation valves closed as expected at the Lo-Lo steam generator level setpoint. Steam generator level was promptly restored above the Lo-Lo steam generator setpoint. There was no impact on the reactor cooldown that was concurrently in progress as part of the preparation for refueling. Initial screening of the condition determined as not reportable in accordance with 10 CFR 50.72(b)(3)(iv), however, based upon further review it has been determined the condition is reportable. | ||
At the time of the event, both trains of shutdown cooling were in service and there were no challenges to offsite power. The licensee was not required to enter any Technical Specification LCO action statements as a result of the event, and the licensee is still investigating the cause of the decrease in steam generator level below the Lo-Lo level setpoint. | At the time of the event, both trains of shutdown cooling were in service and there were no challenges to offsite power. The licensee was not required to enter any Technical Specification LCO action statements as a result of the event, and the licensee is still investigating the cause of the decrease in steam generator level below the Lo-Lo level setpoint. | ||
Latest revision as of 22:09, 1 March 2018
| Where | |
|---|---|
Byron  Illinois (NRC Region 3) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(iv)(A), System Actuation | |
| Time - Person (Reporting Time:+77.23 h3.218 days <br />0.46 weeks <br />0.106 months <br />) | |
| Opened: | Blaine Peters 15:17 Apr 22, 2010 |
| NRC Officer: | Ryan Alexander |
| Last Updated: | Apr 22, 2010 |
| 45867 - NRC Website
| |