ENS 51532

v t e ENS Event
16:32 Nov 12, 2015
Title	Automatic Reactor Scram
Event Description	At 1132 hours0.0131 days <br />0.314 hours <br />0.00187 weeks <br />4.30726e-4 months <br /> [EST] on November 12, 2015, Susquehanna Steam Electric Station Unit 1 reactor automatically scrammed due to one Main Steam Isolation Valve (MSIV) unanticipated closure causing a High Pressure RPS [Reactor Protection System] trip. All control rods inserted and both reactor recirculation pumps tripped due to reactor water level 2. Reactor water level lowered to -37 inches causing Level 3 (+13 inches) and level 2 (-38 inches) (Division 2 only) isolations. RCIC [Reactor Core Isolation Cooling] automatically initiated and was overridden by control room operators after RPV [Reactor Pressure Vessel] water level was restored to the normal band with feedwater. All isolations and initiations occurred as expected. No main steam relief valves opened. Pressure was controlled via main turbine bypass valve operation. All safety systems operated as expected. The Unit 1 reactor is currently stable in Mode 3. Investigation into the cause of the MSIV closure is underway. Unit 2 was unaffected and continues power operation. The NRC Resident Inspector has been notified. A voluntary notification to PEMA [Pennsylvania Emergency Management Agency] and press release will occur. The plant is in its normal shutdown electrical lineup.

ENS 51532 +/-
Where
Susquehanna Pennsylvania (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:+-1.28 h-0.0533 days <br />-0.00762 weeks <br />-0.00175 months <br />)
Opened:	Lonnie Crawford 15:15 Nov 12, 2015
NRC Officer:	Mark Abramovitz
Last Updated:	Nov 12, 2015
51532 - NRC Website
v • d • e

v t e Emergency Notification System
Susquehanna with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation
WEEKMONTHYEAR2023-03-23T21:36:00 [Table view]
[ENS list for Susquehanna]

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