|Entered date||Site||Region||Scram||Reactor type||Event description|
|ENS 52292||9 October 2016 06:09:00||Surry||NRC Region 2||Automatic Scram||Westinghouse PWR 3-Loop||Surry Unit 2 reactor automatically tripped at 0254 hours on 10/09/2016, due to a Main Generator Differential Lockout Turbine Trip. The cause of the generator differential lockout is under investigation at this time. Reactor Coolant System temperature is currently being maintained at 547 degrees Fahrenheit on the main steam dump valves. All three Auxiliary Feedwater Pumps automatically started as designed on Low-Low Steam Generator Water Level following the trip. Auxiliary feedwater pumps have since been secured and Main Feedwater is in use. All systems operated as required. The source range nuclear instruments had to be manually reinstated following the reactor trip due to indications of undercompensation on Intermediate Range Nuclear Instrument channel N-36. Off site power remains available. There is no impact on Surry Unit 1. This notification is being made pursuant to 10CFR50.72(b)(2)(iv)(B) for 4-hour notification of Reactor Protection System activation and 10CFR50.72(b)(3)(iv)(A) for 8-hour notification of automatic actuation of the Auxiliary Feedwater System. The NRC Resident Inspector has been notified and is responding to the site. There were no radiation releases, personnel injuries, or contamination events due to this event. All control rods fully inserted. Secondary reliefs lifted and reseated as expected following a reactor trip from 100% power.|
|ENS 50529||13 October 2014 11:13:00||Surry||NRC Region 2||Automatic Scram||Westinghouse PWR 3-Loop||Unit 2 reactor automatically tripped at 0758 (EDT) hours on 10/13/2014, due to a spurious overpower/delta temperature signal on all three channels. The cause of the spurious signal is unknown at this time. Currently, reactor coolant system temperature is being maintained stable at 546 (F) degrees. All three auxiliary feedwater pumps automatically initiated as designed on low-low steam generator level following the trip. All systems responded as expected with the exception (both) of the intermediate range neutron indication(s), which was determined to be under-compensated. The source range indication did not automatically energize and was energized manually. All other systems operated as required. This notification is being made pursuant to 10 CFR 50.72(b)(2)(iv)(B) for 4-hour notification of reactor protection system activation and 10 CFR 50. 72(b )(3)(iv)(A) for 8-hour notification of automatic actuation of auxiliary feedwater. The NRC resident has been notified of this event and is on site. There were no radiation releases due to this event, nor were there any personnel injuries or contamination events. There was no testing in progress when the reactor trip occurred. The reactor trip was considered uncomplicated. All control rods fully inserted. Decay heat is being released via main feedwater and the condenser steam dumps. Normal offsite power is available. There was no effect on Surry Unit 1 which continues to operate at 100% power. The licensee is investigating the cause of the overpower/delta temperature actuation.|
|ENS 46761||16 April 2011 19:24:00||Surry||NRC Region 2||Automatic Scram||Westinghouse PWR 3-Loop|
At 1849 hrs, Surry Power Station (SPS) Unit 1 and Unit 2 experienced an automatic Reactor Trip from a Loss of Offsite Power, as a result of a tornado touching down in the station's switchyard. Unit 1 reactor tripped as a result of a Loss of Coolant Flow > P-8 (35% power), and the Unit 2 reactor tripped as a result of a 500 kV Leads Differential Turbine-Generator trip. Both units responded as designed. Unit 1 electrical power is being provided by Number 1 Emergency Diesel Generator (EDG) to the 1H emergency bus, with the Station Blackout (SBO) diesel loaded on to the 1J emergency bus. Unit 2 electrical power is being supplied by the number 2 EDG to the 2H emergency bus, with the number 3 EDG loaded on to the 2J emergency bus. All Unit 1 control rods inserted on the reactor trip, and all Unit 2 control rods inserted on its respective reactor trip. The Low Level Intake Structure (LLIS) is without power. All three Emergency Service Water Pumps are running to supply the intake canal. Efforts are underway to restore Bus 7, which will give each unit an emergency bus powered by offsite power (Unit 1 1J, Unit 2 2H) and restore power to the LLIS. Decay heat is being removed by auxiliary feedwater on both units and atmospheric steam release via the steam generator PORVs. Both units are currently on natural circulation. All other system parameters are normal and stable. At 1855 hrs a NOUE was declared due to a loss of offsite power (applicable to U1 and U2). Additionally, due to an estimated 100 gallon fuel oil spill from an above ground storage tank near the station's garage, the Virginia State Department of Environmental Quality was notified at 2041 and the Surry County Local Emergency Planning Coordinator was notified at 2114. At 2334, the Virginia State Department of Environmental Quality was notified and the Surry County Local Emergency Planning Coordinator was notified at 2336, due to an estimated 200 gallon oil leak to the ground from a station switchyard transformer damaged during the tornado. The NRC Resident Inspector has been notified and is on-site. Notified DHS (Rickerson), FEMA (Boscoe), DOE (Turner), HHS (Hoskins), and USDA (Russell). See related EN #46762
The licensee exited the emergency condition at 0745 EDT on 4/19/11. Offsite power has been restored, and the plant is shutdown and cooled down. Notified R2DO (O'Donohue), NRR EO (Thorpe) and IRD (Gott). Informed the following Federal Agencies via Blast Dial: DHS, FEMA, USDA, HHS and DOE.
|ENS 46584||2 February 2011 08:52:00||Surry||NRC Region 2||Automatic Scram||Westinghouse PWR 3-Loop||Unit 2 Reactor automatically tripped at 0533 EST. This was due to loss of coolant flow in the 'C' RCS Loop. The first indication of the reactor trip was the annunciator for 'Loss of Coolant Flow > P8.' The 'C' RCP is running with motor current indicating normal. 'C' LOOP RCS flow is approximately 25% on all three channels with 'A' & 'B' RCS LOOP FLOW approximately 104%. All three auxiliary feedwater (AFW) pumps automatically initiated as designed on low-low steam generator level following the trip. Currently, RCS temperature is being maintained stable at no load temperature. All systems responded as expected with the exception of the Intermediate Range Neutron Indication. N36 indication was undercompensated and Source Range indication did not automatically energize, but was subsequently manually energized. This notification is being made pursuant to 10 CFR 50.72(b)(2)(iv)(B) for 4-hour notification of RPS Activation and 10 CFR 50.72(b)(3)(iv)(A) for 8-hour notification of actuation of AFW. Plant responded as expected. The NRC Resident Inspector has been notified of this event and is on site. There were no radiation releases due this event, nor were there any personnel injuries or contamination events. This was an uncomplicated reactor trip and all control rods fully inserted. The plant is in a normal electrical alignment. AFW has been secured and the steam generators are being feed from main feedwater. Decay heat is being released through the main condenser steam dumps. Estimated time for repair and re-start is not known.|
|ENS 45986||8 June 2010 12:00:00||Surry||NRC Region 2||Automatic Scram||Westinghouse PWR 3-Loop||At 0948 hours (EDT) on 6/8/10, a Unit 1 vital AC bus was lost when the uninterruptible power supply inverter failed while the alternate AC source was out of service for scheduled maintenance. The loss of the vital bus inverter caused a loss of 120 VAC vital bus 1-III. The loss of this vital bus caused the 'A' main feed pump recirculation valve to fail open and also caused 2 of the 3 main feedwater regulating valves to fail to automatic-hold mode of operation. This combination of as designed failures resulted in a reduction in main feedwater flow and resulted in an automatic reactor trip due to a feed flow steam flow mismatch in conjunction with low steam generator level. The loss of vital bus 1-III also resulted in initiation of safety injection due to loss of vital bus 1-III instrumentation in conjunction with the expected momentary RCS cooldown below 543 DEG-F. The safety injection resulted from the high steam flow in conjunction with low RCS T-ave actuation signal. The safety injection actuation also resulted in automatic start of the #1 Emergency Diesel and the #3 Emergency Diesel Generators. Neither EDG was required to load since off-site power remained operable. The loss of vital bus 1-III also resulted in loss of numerous field inputs to the Plant Computer System (PCS) and resulted in non-functionality of the SPDS (Safety Parameter Display System). The PCS itself remains functional along with MCR (Main Control Room) annunciators and sufficient MCR instrumentation to monitor critical safety functions. All three auxiliary feedwater pumps automatically initiated as designed on low-low steam generator level following the trip. Currently, RCS temperature is being maintained stable at 547 degrees. All systems functioned as required following the reactor trip. During the post-trip transient, pressurizer PORV (Power Operated Relief Valve), PCV-1455C, cycled as required to maintain RCS pressure due to the safety injection and the loss of normal letdown. There were no radiation releases due to this event, nor were there any personnel injuries or contamination events. This event is being reported in accordance with 10CFR50.72(b)(2)(iv)(B), 10CFR50.72(b)(2)(iv)(A), 10CFR50.72(b)(3)(iv)(A), and 10CFR50.72(b)(3)(xiii). The NRC Resident Inspector was notified of this event. During the trip, all rods inserted into the core. In addition to the pressurizer PORV lifting, a secondary main steam relief valve lifted. All relief valves properly reseated and there is no known primary to secondary leakage. The plant is in its normal shutdown electrical lineup. Main steam trip valves were isolated during the transient. Decay heat is being removed via main steam bypasses to the condenser and steam generator power operated relief valves.|
|ENS 45528||29 November 2009 13:31:00||Surry||NRC Region 2||Manual Scram||Westinghouse PWR 3-Loop||During startup physics testing, the reactor operator identified a discrepancy between Group 1 & Group 2 Step Demand Counters for control bank 'B'. Research identified the issue to be associated with failure of a card in the rod control power cabinet. Failure of the card impacts group step counters for control bank 'B', control bank 'D' and shutdown bank 'B.' Inoperability of more than one group step counter per bank placed Unit 2 in a 6-hour clock to hot shutdown as of 0808 hrs 29 November 2009. Consequently, at 1045 hrs, the decision was made to trip Unit 2 reactor. The decision was based on time required to make repairs, complete post maintenance testing requirements, and maintaining proper control of reactivity. All systems functioned as required on the trip and initiation of any auxiliary or emergency systems was not required. Current heat removal is via normal plant alignment following refueling outage activities: steam generator blowdown, main feedwater, and steam generator PORV. All control rods fully inserted on the manual trip. The licensee notified the NRC Resident Inspector.|
|ENS 44152||21 April 2008 00:37:00||Surry||NRC Region 2||Manual Scram||Westinghouse PWR 3-Loop||While ramping the Unit 1 Turbine following a forced unit outage, vibrations on the number 4 bearing increased to 13.9 mils. The ramp was stopped and a rapid load reduction was initiated. Due to sustained vibrations (>14.1 mils) after ramping the turbine down, the Unit 1 reactor was manually tripped. Unit 1 has been stabilized at Hot Shutdown. All three auxiliary feedwater pumps automatically initiated as designed on low-low steam generator level following the trip. Currently RCS temperature is being maintained stable at 547 degrees. All systems functioned as required following the reactor trip. There were no radiation releases due to this event, nor were there any personnel injuries or contamination events. This event is being reported in accordance with 10 CFR 50.72 (b)(2)(iv) and 10 CFR 50.72 (b)(3)(iv). Upon exiting the refueling outage in 11/07 the main turbine had a vibration issue of about 11 or 12 mils. Decay heat is being removed via the steam dumps to the condenser. Unit 2 was not affected during this event. Offsite power was lined up normally. The licensee notified the NRC Resident Inspector.|
|ENS 42888||7 October 2006 18:27:00||Surry||NRC Region 2||Manual Scram||Westinghouse PWR 3-Loop|
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 hours 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).
|ENS 41383||8 February 2005 00:14:00||Surry||NRC Region 2||Manual Scram||Westinghouse PWR 3-Loop|
The following information was provided by the licensee via facsimile: While withdrawing Control Bank 'A' during the Reactor Startup, Rod B-10 indicated a rapid drop from approximately 42 steps to 17 steps on the CERPI (Computer Enhanced Rod Position Indication) panel. The reactor operator stopped withdrawal of 'A' control bank and the CERPI indication for rod B-10 remained at 17 steps. The remaining CERPIs in 'A' control bank varied from 40 to 45 steps. The startup was terminated and the reactor was manually tripped in accordance with AP-1 and 1-E-0 (was) initiated. All systems functioned as required on the trip. Initial investigation by I & C and Engineering found no problems with the CERPI indication. Rod Drop time data from the CERPI program shows all rods in Control Bank 'A' had a drop time of 0.32 to 0.38 seconds with the exception of B-10, which had a drop time of 0.18 seconds.
An investigation is ongoing as to the cause of rod B-10 misalignment.
This notification is being made pursuant to 10 CFR 50.72(b)(3)(iv)(A). The NRC resident was notified of this event. The reactor was subcritical in the Source Range at the initiation of the event. All rods inserted fully during the manual reactor trip. S/G level is being maintained by main feedwater and decay heat removal is via the S/G PORV.
|ENS 40769||22 May 2004 00:28:00||Surry||NRC Region 2||Automatic Scram||Westinghouse PWR 3-Loop||Unit 2 Reactor tripped at 2108, first out is F-E-2, 500KV leads differential lockout relay trip. This notification is being made pursuant to 10 CFR 50.72(b)(2)(iv)(B) for 4-hour notification of RPS Activation and 10 CFR 50.72(b)(3)(iv)(A) for 8-hour notification of automatic actuation of AFW. Plant responded as expected with the exception of 'C' SG AFW flow indication. The 'C' SG level responded normally to Unit conditions. The NRC resident has been notified of this event and is on site. Notification was made to NRC duty officer upon declaration on NOUE(See EN#40768), which was declared based on EAL Tab K-6 for 'Confirmed report of unplanned explosion within Protected Area or Switchyard.' An electrical fault was observed in the 500 KV switchyard and is currently being investigated. No further damage has been detected in the switchyard. The NOUE, which was declared at 2116, has been terminated as of 2256. Reactor shutdown with all control rods fully inserted. Electric plant is in a normal shutdown mode lineup. The other operating unit was unaffected by this event. Decay heat is being removed to the main condenser using the condenser steam dump valves. See Surry Unit 2 event # 40770 & 40771.|
|ENS 40168||18 September 2003 09:16:00||Surry||NRC Region 2||Manual Scram||Westinghouse PWR 3-Loop|
At 0900 EDT the licensee declared an Unusual Event as a precautionary measure due to expected severe weather from hurricane Isabel. Current wind speed and direction is 10-15 mph sustained with gusting to 20 mph from the NNE direction. No additional staff other than those for the planned outage have been brought onsite. The licensee informed state/local agencies and the NRC Resident Inspector.
As of 1600 ET, Surry Unit 1 commenced a power reduction of 200 mwe (100% to approximately 75% power) in anticipation of grid instabilities due to heavy weather. One of eight circ water screens is degraded due to river debris and its associated circulating water pump has been secured. On-site meteorological panels are out of service. Additionally, the Emergency Operating Facility (EOF) is out of service due to a loss of power. Notified R2DO (A. Boland).
The following was received via fax from the licensee: With Surry Power Station Unit 1 at approximately 75% reactor power and Unit 2 at 100% reactor power, a manual reactor trip was initiated on Unit 1 at 1728 and on Unit 2 at 1732, due to the loss of the '1G' and `2G' buses which supply power to all eight circulating water pumps for both units. The loss of the buses occurred during high winds and rain associated with Hurricane Isabel, although no hurricane force winds were onsite prior to or at the time of the event. A discretionary Notification of Unusual Event had been declared earlier at 0900 due to the severe weather. On Unit 1, the 'B' inadequate core cooling monitor (ICCM) failed. The 'A' ICCM remained operable throughout. All control rods fully inserted and the shutdown margin for Unit 1 was determined to be satisfactory. On Unit 2, eight rod position indicators showed greater than 10 steps but less than 20 steps following the reactor trip. Emergency boration was initiated. All Unit 2 IRPIs (Individual Rod Position Indications) are currently indicating less than five steps and the shutdown margin was satisfactory. Auxiliary feedwater automatically initiated as designed for both units on low low steam generator level following the trip. Primary RCS temperature decreased to approximately 543 and 538 degrees on Unit 1 and 2 respectively and was stabilized at 547 degrees. No primary safety or relief valves were actuated during the event on either unit. As a result of the loss of the circulating water pumps, the emergency service water pumps were started to conserve intake canal level. After start, 2 out of the 3 emergency service water pumps tripped on high water temperature. The pumps were checked and restarted 14 minutes later. Also due to the need to conserve intake canal level, the main steam trip valves on both units were closed and primary temperature is being maintained by use of the secondary power operated relief valves. No indication of primary to secondary leakage exists on either unit, therefore no adverse radiological consequences resulted from this event. Both units are currently stable at hot shutdown. At 1845, the 2G bus was energized and circulating water pumps were started. The emergency service water pumps were secured and are in standby. This 4 hour and 8 hour report is being made for Surry Units 1 and 2 in accordance with 10 CFR 50.72(b)(2)(iv)(B) and 10 CFR 50.72(b)(3)(iv)(A). Notified R2DO (A. Boland), NRR EO (J. Calvo), DIRO (R. Wessman), FEMA (Chuck Bagwell), DHS (Colleen Wilson).
The licensee terminated their unusual event due to the following conditions: - severe weather has left the area - both units are stable at hot shutdown on offsite power - 2 of 3 ESW pumps are operable, and the third ESW pump is being prepared for an operational test - 45 of 67 sirens remain inoperable, but the sirens will be restored when power to the grid is restored The licensee will notify the NRC Senior Resident Inspector, as well as state and local officials Notified R2DO (Boland), NRR EO (Calvo), DIRO (McGinty), FEMA (M. Eaches), DHS (D. Licastro)