ENS 45489
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ENS Event | |
|---|---|
23:43 Nov 11, 2009 | |
| Title | Manual Reactor Scram After a Turbine Hydraulic Fluid Leak |
| Event Description | On November 11, 2009, at 1743 CST the reactor was manually scrammed following a manual trip of the main turbine due to an un-isolable leak on the Turbine High Pressure Fluid System (TGF) governor valve 3. Initial power level when the leak was identified was approximately 70%. Power was lowered commencing at 1405 in accordance with shutdown procedures. The reactor operator scrammed the reactor at 17:43 from approximately 15% power when directed by the shutdown procedure to place the reactor in a condition to support repairs to the TGF system. In preparation for the scram, level was raised to the range specified in the shutdown procedure (approximately 46 inches). Following the scram, reactor vessel water level lowered to approximately 15 inches on the narrow range instruments, and was subsequently recovered to normal post scram range (approximately 40 inches) using the reactor feedwater system. All control rods fully inserted. No group isolations occurred since level did not reach the isolation setpoint (3 inches). At 1920, the inboard MSIVs were manually closed to stabilize plant cool down and maintain the plant in mode 3. The main condenser remained available throughout the evolution and condenser vacuum is currently being maintained by the mechanical vacuum pumps. Pressure is being controlled using the steam line drains to the main condenser.
All equipment operated as expected and there were no difficulties encountered during the evolution. The TGF System has been secured and is in the process of being tagged out for repair. This event is reportable under 10CFR50.72(b)(2)(iv)(B) due to a non planned reactor scram while critical. The licensee has notified the NRC Resident Inspector. The plant is in its normal shutdown electrical lineup. |
| Where | |
|---|---|
Cooper  Nebraska (NRC Region 4) | |
| Reporting | |
| 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation | |
| LER: | 05000298/LER-2009-004 |
| Time - Person (Reporting Time:+-1.15 h-0.0479 days <br />-0.00685 weeks <br />-0.00158 months <br />) | |
| Opened: | John Myers 22:34 Nov 11, 2009 |
| NRC Officer: | Mark Abramovitz |
| Last Updated: | Nov 11, 2009 |
| 45489 - NRC Website | |
Unit 1 | |
|---|---|
| Reactor critical | Critical |
| Scram | Yes, Manual Scram |
| Before | Power Operation (15 %) |
| After | Hot Shutdown (0 %) |
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