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| Entered date | Event description | |
|---|---|---|
| ENS 44942 | 28 March 2009 03:45:00 | At 0146 EDT 3/28/09, the reactor mode switch was taken to shutdown in response to high vibration levels on the Main Turbine #1 bearing. Reactor power was at its reduced level in preparation for entry into Refueling Outage #13 which was scheduled to begin at 0300 EDT. All control rods fully inserted into the core. The lowest reactor vessel water level reached was 162 inches. HPCI & RCIC did not initiate. No safety relief valves (SRV) actuated. Reactor water level is being controlled in the normal band using the Control Rod Drive (CRD) system. All isolations and actuations for reactor vessel water level 3 occurred. The cause of the high main turbine vibrations is currently under investigation. There was no maintenance or testing in progress that would explain the high turbine vibration levels. At the time of the scram all ECCS systems and Emergency Diesel Generators were operable. This report is being made in accordance with 10CFR50.72(b)(2)(iv)(B), any event that results in actuation of the reactor protection system (RPS) when the reactor is critical. The Licensee notified the NRC Resident Inspector. |
| ENS 44698 | 5 December 2008 00:21:00 | On December 4, 2008 at 1735 during steam line warming as part of a planned HPCI pump and valve surveillance, a 4 hour Limiting Condition for Operation was entered for the HPCl Steam Supply Outboard Isolation Valve Bypass Valve (E4150F600) per LCO 3.6.1.3 with the action being to isolate the penetration. This was due to abnormal indications observed from the Main Control Room during movement of the valve. On December 4, 2008 at 2118, unplanned HPCI inoperability occurred due to isolating the HPCI Steam Supply Inboard Isolation Valve (E4150F002) to satisfy LCO 3.6.1.3 1 for the HPCI Steam Supply Outboard Isolation Valve Bypass Valve (E4150F600) inoperability. A 14 day LCO was entered for HPCI per LCO 3.5.1. This report is being made pursuant to 10CFR50.72(b)(3)(v)(D) as a condition that at the time of discovery could have prevented the fulfillment of a safety function to mitigate the consequences of an accident based on loss of a single train safety system. The NRC Resident Inspector has been notified. |