ENS 40686: 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 = 03/20/2004 15:59 EDT | | event date = 03/20/2004 15:59 EDT | ||
| last update date = 04/26/2004 | | last update date = 04/26/2004 | ||
| title = Invalid Actuation | | title = Invalid Actuation of the Motor Driven Emergency Feedwater Pumps | ||
| event text = By design, the Steam Generator (SG) Dry-out Protection Circuit actuates whenever two level indications (two of two actuation logic) in either SG are lower than the setpoint for more than 30 seconds. This start circuit is not credited in any ONS safety analysis, therefore this signal is considered an INVALID signal with respect to 50.73 (a)(2)(iv)(A). Upon actuation, the circuit starts both Motor Driven Emergency Feedwater Pumps (MDEFWPs) on the affected unit. It does not send a start signal to the Turbine Driven Emergency Feedwater Pump. | | event text = By design, the Steam Generator (SG) Dry-out Protection Circuit actuates whenever two level indications (two of two actuation logic) in either SG are lower than the setpoint for more than 30 seconds. This start circuit is not credited in any ONS safety analysis, therefore this signal is considered an INVALID signal with respect to 50.73 (a)(2)(iv)(A). Upon actuation, the circuit starts both Motor Driven Emergency Feedwater Pumps (MDEFWPs) on the affected unit. It does not send a start signal to the Turbine Driven Emergency Feedwater Pump. | ||
Shortly after entering Mode 4, a control operator stopped one of two operating Reactor Coolant Pumps per the Unit shutdown procedure. A second control operator was manually controlling Feedwater and reduced flow to control the system cooldown rate, without recognizing that the 2B SG had reached the low level setpoint for SG Dry-out Protection Circuit actuation. | Shortly after entering Mode 4, a control operator stopped one of two operating Reactor Coolant Pumps per the Unit shutdown procedure. A second control operator was manually controlling Feedwater and reduced flow to control the system cooldown rate, without recognizing that the 2B SG had reached the low level setpoint for SG Dry-out Protection Circuit actuation. | ||
Latest revision as of 22:23, 1 March 2018
| Where | |
|---|---|
Oconee  South Carolina (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+735.93 h30.664 days <br />4.381 weeks <br />1.008 months <br />) | |
| Opened: | Randy Todd 10:55 Apr 20, 2004 |
| NRC Officer: | Arlon Costa |
| Last Updated: | Apr 26, 2004 |
| 40686 - NRC Website
| |