ENS 42084: Difference between revisions
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| event date = 08/31/2005 18:05 EDT | | event date = 08/31/2005 18:05 EDT | ||
| last update date = 10/27/2005 | | last update date = 10/27/2005 | ||
| title = Invalid Actuation | | title = Invalid Actuation of an Emergency Diesel Generator | ||
| event text = This telephone notification to report an invalid actuation is provided in accordance with 10 CFR 50.73(a)(1), which states, 'In the case of an invalid actuation reported under Sec. 50.73(a)(2)(iv), other than actuation of the reactor protection system (RPS) when the reactor is critical, the licensee may, at its option, provide a telephone notification to the NRC Operations Center within 60 days after discovery of the event instead of submitting a written LER.' The specific reporting requirement in 10 CFR 50.73(a)(2)(iv)(A), states, 'Any event or condition that resulted in manual or automatic actuation of any of the systems listed in paragraph (a)(2)(iv)(B).' For this report, the affected system was the emergency AC electrical power systems as listed in 10 CFR 50.73(a)(2)(iv)(B)(8). Specifically, the Train A emergency diesel generator (EDG) automatically started due to an invalid system actuation. | | event text = This telephone notification to report an invalid actuation is provided in accordance with 10 CFR 50.73(a)(1), which states, 'In the case of an invalid actuation reported under Sec. 50.73(a)(2)(iv), other than actuation of the reactor protection system (RPS) when the reactor is critical, the licensee may, at its option, provide a telephone notification to the NRC Operations Center within 60 days after discovery of the event instead of submitting a written LER.' The specific reporting requirement in 10 CFR 50.73(a)(2)(iv)(A), states, 'Any event or condition that resulted in manual or automatic actuation of any of the systems listed in paragraph (a)(2)(iv)(B).' For this report, the affected system was the emergency AC electrical power systems as listed in 10 CFR 50.73(a)(2)(iv)(B)(8). Specifically, the Train A emergency diesel generator (EDG) automatically started due to an invalid system actuation. | ||
On August 31, 2005, at approximately 1805 hours (EDT), with H. B. Robinson Steam Electric Plant (HBRSEP), Unit No. 2, operating in MODE 1 at approximately 100% power, the Train A EDG automatically started from the standby condition. The EDG did not automatically connect to the associated emergency bus (E-1), because no E-1 bus undervoltage (UV) signal was present. The automatic start was caused by a failed solenoid-operated valve (SOV) in the air start system for the EDG (valve number DA-23A). The SOV failed-open, which is the designed failure-mode condition for this valve. This admitted air to the EDG air-start distributor, which started the Train A EDG. No additional failures or abnormalities were noted. The Train A EDG successfully started and achieved the required speed and voltage, but as stated previously, the EDG did not load because no UV signal was present on the associated bus. | On August 31, 2005, at approximately 1805 hours (EDT), with H. B. Robinson Steam Electric Plant (HBRSEP), Unit No. 2, operating in MODE 1 at approximately 100% power, the Train A EDG automatically started from the standby condition. The EDG did not automatically connect to the associated emergency bus (E-1), because no E-1 bus undervoltage (UV) signal was present. The automatic start was caused by a failed solenoid-operated valve (SOV) in the air start system for the EDG (valve number DA-23A). The SOV failed-open, which is the designed failure-mode condition for this valve. This admitted air to the EDG air-start distributor, which started the Train A EDG. No additional failures or abnormalities were noted. The Train A EDG successfully started and achieved the required speed and voltage, but as stated previously, the EDG did not load because no UV signal was present on the associated bus. | ||
Latest revision as of 21:19, 1 March 2018
| Where | |
|---|---|
Robinson  South Carolina (NRC Region 2) | |
| Reporting | |
| 10 CFR 50.73(a)(1), Submit an LER, Invalid Actuation | |
| Time - Person (Reporting Time:+1355.57 h56.482 days <br />8.069 weeks <br />1.857 months <br />) | |
| Opened: | Curtis Castell 09:39 Oct 27, 2005 |
| NRC Officer: | Bill Huffman |
| Last Updated: | Oct 27, 2005 |
| 42084 - NRC Website
| |