ENS 46409: Difference between revisions

v t e ENS Event
15:56 Nov 10, 2010
Title	Unplanned Automatic Scram and High Pressure Coolant Injection System Initiation During Testing
Event Description	At 10:56 [EST] on Wednesday, November 10, 2010, Nine Mile Point Unit [1] One automatically scrammed from rated power. The cause of the scram was Main Steam Isolation Valve (MSIV) closure. The MSIV closure occurred during Instrument and Control Lo-Lo Level Surveillance Testing. The Lo-Lo Surveillance Test has been secured and all Reactor Protection System (RPS) Level Signals returned to normal. Two of four MSIVs went closed; troubleshooting to follow to determine the cause of the equipment malfunction [unexpected MSIV closure]. Following the automatic scram, the High Pressure Coolant Injection (HPCI) System automatically initiated. At Nine Mile Point Unit One, a HPCI System actuation signal on low Reactor Pressure Vessel (RPV) level is normally received following a reactor scram, due to level shrink. At 10:58, RPV level was restored above the HPCI System low level actuation set point and the HPCI System initiation signal was reset. Pressure control was initially established on the Emergency Condensers (ECS). The MSIVs have been re-opened and the normal heat removal capability has been re-established [to the Main Condensers]. All off-site power sources remain available [with a normal electrical alignment]. 10 CFR 50.72(b)(2)(iv)(B) requires reporting within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> when a valid actuation of the Reactor Protection System occurs. 10 CFR 50.72(b)(3)(iv)(A) requires reporting within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> when a valid actuation of the High Pressure Coolant Injection System occurs. There are no other adverse impacts to the station based on this event. All control rods inserted and the unit is stable in Mode 3 with reactor pressure and temperature approximately 600 psig and 480 degrees. All other safety systems operated as expected. The licensee notified the NRC Resident Inspector and the New York State Public Service Commission.

ENS 46409 +/-
Where
Nine Mile Point New York (NRC Region 1)
Reporting

10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation
Time - Person (Reporting Time:+-2.93 h-0.122 days <br />-0.0174 weeks <br />-0.00401 months <br />)
Opened:	Benjamin Geiss 13:00 Nov 10, 2010
NRC Officer:	John Shoemaker
Last Updated:	Nov 10, 2010
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v • d • e

v t e Emergency Notification System
Nine Mile Point with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation
WEEKMONTHYEAR2024-09-23T11:20:00 [Table view]
[ENS list for Nine Mile Point]

@@ Line 16: / Line 16: @@
 | event date = 11/10/2010 10:56 EST
 | last update date = 11/10/2010
-| title = Unplanned Automatic Scram And High Pressure Coolant Injection System Initiation During Testing
+| title = Unplanned Automatic Scram and High Pressure Coolant Injection System Initiation During Testing
 | event text = At 10:56 [EST] on Wednesday, November 10, 2010, Nine Mile Point Unit [1] One automatically scrammed from rated power. The cause of the scram was Main Steam Isolation Valve (MSIV) closure. The MSIV closure occurred during Instrument and Control Lo-Lo Level Surveillance Testing. The Lo-Lo Surveillance Test has been secured and all Reactor Protection System (RPS) Level Signals returned to normal. Two of four MSIVs went closed; troubleshooting to follow to determine the cause of the equipment malfunction [unexpected MSIV closure].
 Following the automatic scram, the High Pressure Coolant Injection (HPCI) System automatically initiated. At Nine Mile Point Unit One, a HPCI System actuation signal on low Reactor Pressure Vessel (RPV) level is normally received following a reactor scram, due to level shrink.  At 10:58, RPV level was restored above the HPCI System low level actuation set point and the HPCI System initiation signal was reset. Pressure control was initially established on the Emergency Condensers (ECS). The MSIVs have been re-opened and the normal heat removal capability has been re-established [to the Main Condensers].

v t e Unit 1
GE-2
Reactor critical	Critical
Scram	A/R
Before	Power Operation (100 %)
After	Hot Shutdown (0 %)

ENS 46409: Difference between revisions

Latest revision as of 21:08, 1 March 2018

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ENS 46409: Difference between revisions

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