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ENS 52795
Show incoming properties 
Category
ENS Notification  and Power Reactor
CFR
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(b)(3)(iv)(A), System Actuation +  and 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge +
Current power
0  +  and 100  +
Current reactor mode
Power Operation +  and Hot Shutdown +
Description
At 1527 hrs (EDT) on June 8, 2017, Susqueh … At 1527 hrs (EDT) on June 8, 2017, Susquehanna Steam Electric Station Unit 1 reactor automatically scrammed due to a loss of Main Turbine Electro-Hydraulic Control (EHC) logic power causing a High Flux Reactor Power RPS (Reactor Protection System) trip. </br>All control rods (fully) inserted and both reactor recirculation pumps tripped due to reaching reactor water level 2. Reactor water level lowered to -49 inches causing Level 3 (+13 inches) and Level 2 (-38 inches) isolations. HPCI (High Pressure Coolant Injection) and RCIC (Reactor Core Isolation Cooling) automatically initiated and were overridden by control room operators after RPV (Reactor Pressure Vessel) water level was restored to the normal band with feedwater. HPCI and RCIC injected to the Reactor Coolant System during reactor level stabilization. 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. </br>Secondary Containment Zone 1, 2, and 3 differential pressure lowered to 0 inch WG (Water Gauge) due to a trip of the Reactor Building Ventilation system that resulted from Unit 1 Level 2 isolation. Differential pressure was restored to Zones 1, 2, and 3 by the initiation of Standby Gas Treatment System on the Unit 1 Level 2 initiation. </br>Unit 1 reactor is currently stable in Mode 3. Investigation into the loss of Main Turbine EHC logic power is underway. </br>The NRC Resident Inspector has been notified. A voluntary notification to PEMA and press release will occur.</br>The suspected cause of the loss of power to the EHC logic circuit is ongoing maintenance on the system.cuit is ongoing maintenance on the system.  +
Discovered date
19:27:00, 8 June 2017  +
ENS id number
52,795  +
Emergency class
Non Emergency +
Entered date
19:10:00, 8 June 2017  +
Event date
19:27:00, 8 June 2017  +
Event description
At 1527 hrs (EDT) on June 8, 2017, Susqueh … At 1527 hrs (EDT) on June 8, 2017, Susquehanna Steam Electric Station Unit 1 reactor automatically scrammed due to a loss of Main Turbine Electro-Hydraulic Control (EHC) logic power causing a High Flux Reactor Power RPS (Reactor Protection System) trip. </br>All control rods (fully) inserted and both reactor recirculation pumps tripped due to reaching reactor water level 2. Reactor water level lowered to -49 inches causing Level 3 (+13 inches) and Level 2 (-38 inches) isolations. HPCI (High Pressure Coolant Injection) and RCIC (Reactor Core Isolation Cooling) automatically initiated and were overridden by control room operators after RPV (Reactor Pressure Vessel) water level was restored to the normal band with feedwater. HPCI and RCIC injected to the Reactor Coolant System during reactor level stabilization. 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. </br>Secondary Containment Zone 1, 2, and 3 differential pressure lowered to 0 inch WG (Water Gauge) due to a trip of the Reactor Building Ventilation system that resulted from Unit 1 Level 2 isolation. Differential pressure was restored to Zones 1, 2, and 3 by the initiation of Standby Gas Treatment System on the Unit 1 Level 2 initiation. </br>Unit 1 reactor is currently stable in Mode 3. Investigation into the loss of Main Turbine EHC logic power is underway. </br>The NRC Resident Inspector has been notified. A voluntary notification to PEMA and press release will occur.</br>The suspected cause of the loss of power to the EHC logic circuit is ongoing maintenance on the system.cuit is ongoing maintenance on the system.  +
Has query"Has query" is a predefined property that represents meta information (in form of a <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Subobject">subobject</a>) about individual queries and is provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
ENS 52795 +, ENS 52795 +, ENS 52795 +, ENS 52795 +, ENS 52795 +, ENS 52795 +, ENS 52795 +, ENS 52795 +, ENS 52795 +, ENS 52795 +, ENS 52795 +, ENS 52795 +, ENS 52795 +, ENS 52795 +, ENS 52795 +, ENS 52795 +  and ENS 52795 +
Initial power
100  +
Initial reactor mode
Power Operation +
Last update date
00:00:00, 8 June 2017  +
Modification date"Modification date" is a predefined property that corresponds to the date of the last modification of a subject and is provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a>.
01:42:32, 2 March 2018  +
NRC officer
Mark Abramovitz +
Notification date
19:10:00, 8 June 2017  +
Originated by
Darvin Duttry +
Reactor critical
true  +
Reactor scram
false  +
Reactor type
GE-4 +
Region
NRC Region 1 +
Reporting criterion
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(b)(3)(iv)(A), System Actuation +  and 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge +
Reporting time
-0.0117 d (-0.28 hours, -0.00167 weeks, -3.83544e-4 months)  +
Scram
Automatic Scram +
Site
Susquehanna +
Start date
19:27:00, 8 June 2017  +
State
Pennsylvania +
System
Reactor Coolant System +, Feedwater +, Secondary containment +, Main Turbine +, Reactor Recirculation Pump +, Reactor Building Ventilation +, Standby Gas Treatment System +, Control Rod +, Main Steam +  and Electro-Hydraulic Control +
Title
Automatic Reactor Scram After Main Turbine Control Logic Loss of Power  +
Turbine component
Turbine bypass valve +
URL"URL" is a <a href="/Special:Types/URL" title="Special:Types/URL">type</a> and predefined property provided by <a rel="nofollow" class="external text" href="https://www.semantic-mediawiki.org/wiki/Help:Special_properties">Semantic MediaWiki</a> to represent URI/URL values.
http://www.nrc.gov/reading-rm/doc-collections/event-status/event/2017/20170609en.html#en52795  +
Unit
1  +  and 2  +
 
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