ENS 42888
ENS Event | |
|---|---|
22:01 Oct 7, 2006 | |
| Title | Manual Scram Due to Unusual Noise in Turbine Building |
| Event Description | The main turbine cross-under safety relief valves lifted for no known reason and blew siding off the side of the Unit 2 Turbine building. This siding hit the feeder lines to the A & C Reserve Station Service Transformers (RSSTs). The operator manually scrammed the plant due to swings in steam generator level and unusual noise coming from the turbine building . Unit 2 shutdown currently de-energized A & C Reserve Station Transformers, which effects D & E transfer buses. This also effects 1J bus, which is de-energized, and 1H & 2J buses which are energized with #1 diesel and #3 diesel.
Decay heat removal is being performed thru the SG PORV's and auxiliary feedwater system, with forced cooling from the "B" RCP. Safety related systems are available if required. Notified USDA (A. Jimenez) in addition to the other agencies already identified. The licensee notified the NRC Resident Inspector, as well as State and local agencies.
The site terminated the Alert at 05:40 due to having the "A" RSST in service with bus 1J being powered from its normal power supply. No damage was found from the displaced siding with the exception of the "C" RSST (which should be repaired around noon). The "C" RSST is currently tagged out for maintenance. The licensee notified the NRC Resident Inspector, state, and local governments. Notified: R2DO (Decker), R4DO (Pick), NRR (Dyer, Weber, Quay), IRD (Blount, Wilson), R2 (McCree), DHS (Gray), FEMA (Dunker), DOE (Steve Bailey), EPA (Allison), USDA (Dean Giles), and HHS (Lt. Smith).
At 1827 hours0.0211 days <br />0.508 hours <br />0.00302 weeks <br />6.951735e-4 months <br /> on 10/07/06, an Emergency Notification System (ENS) notification was made for an Alert declaration at Surry Power station. The steam discharge from the turbine system safety valves that had lifted caused pieces of siding from the turbine building to dislodge and come in contact with two phases of the overhead bus for the 'A' and 'C' reserve station service transformers (RSST). The basis for the declaration was the Emergency Action Level (EAL) Tab K-11: 'Notification of missile impact causing damage to safety-related equipment or structures'. Upon further review, the RSSTs were determined not to be safely-related equipment. Therefore, the conditions for an Alert emergency did not exist and the notification is being retracted. A notification will be made to the Virginia Department of Emergency Management. This is being reported In accordance with 10 CFR50.72, (b) (2) (xi). As noted in EN# 42890, conditions for a Notification of Unusual Event (NOUE) did exist at the time of the Alert notification. The licensee notified the NRC Resident Inspector. Notified the R2DO (Henson). |
| Where | |
|---|---|
Surry  Virginia (NRC Region 2) | |
| Reporting | |
| Emergency class: | Alert |
| 10 CFR 50.72(a) (1) (i), Emergency Class Declaration | |
| Time - Person (Reporting Time:+-3.57 h-0.149 days <br />-0.0212 weeks <br />-0.00489 months <br />) | |
| Opened: | Robert Portlock 18:27 Oct 7, 2006 |
| NRC Officer: | John Knoke |
| Last Updated: | Oct 16, 2006 |
| 42888 - NRC Website | |
Unit 2 | |
|---|---|
| Reactor critical | Critical |
| Scram | Yes, Manual Scram |
| Before | Power Operation (100 %) |
| After | Hot Standby (0 %) |
WEEKMONTHYEARENS 471892011-08-23T18:04:00023 August 2011 18:04:00
[Table view]10 CFR 50.72(a)(1)(i), Emergency Class Declaration Notification of an Unusual Event Due to a Seismic Event ENS 467612011-04-16T22:55:00016 April 2011 22:55:00 10 CFR 50.72(b)(2)(xi), Notification to Government Agency or News Release, 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unusual Event Declared Due to Loss of All Offsite Power from Tornado Damage ENS 428882006-10-07T22:01:0007 October 2006 22:01:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Manual Scram Due to Unusual Noise in Turbine Building ENS 411762004-11-06T07:52:0006 November 2004 07:52:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Notice of Unusual Event Due to a Fire in the Unit 1 Turbine Basement ENS 407682004-05-22T01:16:00022 May 2004 01:16:00 10 CFR 50.72(a)(1)(i), Emergency Class Declaration Unusual Event Declared ENS 401682003-09-18T13:00:00018 September 2003 13:00:00 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(a)(1)(i), Emergency Class Declaration, 10 CFR 50.72(b)(3)(iv)(A), System Actuation Unusual Event Declared Due to Expected Severe Weather 2011-08-23T18:04:00 | |