ENS 51982: Difference between revisions

Latest revision as of 20:45, 1 March 2018

v t e ENS Event
16:27 Jun 5, 2016
Title	Reactor Trip and Eccs Actuation Caused by Turbine Governor Valve Failure
Event Description	On June 5, 2016 at 1227 Eastern Daylight Time (EDT), Watts Bar Nuclear Plant (WBN) Unit 2 was in MODE 1 at approximately 12.5% power when a safety injection actuation occurred, followed by an automatic reactor protection system (RPS) trip. Preliminary data suggests that the #1 high pressure turbine governor valve failed open causing a steam header pressure rate of decrease safety injection [SI] actuation signal. As designed, the safety injection actuation caused both trains of the shared Emergency Gas Treatment System (EGTS) to align to Unit 2, requiring WBN Unit 1 to enter Technical Specification (TS) LCO 3.0.3 at 1227 [EDT]. Also as designed, Unit 1 annulus pressure momentarily increased, causing operation personnel to enter LCO 3.6.15 Condition B at 1240 [EDT]. At 1242 [EDT], after annulus pressure normalized, operations personnel exited LCO 3.6.15. At 1245 [EDT], Operations personnel secured safety injection and Unit 2 was stabilized in MODE 3 at normal operating pressure and temperature. By 1349 [EDT], Unit 1 Operations personnel had restored both trains of EGTS to standby readiness, and exited TS 3.0.3. No primary safety barriers (RCS, containment and fuel clad) were challenged and no primary or secondary safety or relief valves actuated during the event. The Unit 2 plant trip was uncomplicated and safety equipment operated as expected. Unit 2 is stable in Mode 3 at normal operating temperature and pressure, in normal shutdown power alignment. Unit 1 is stable in Mode 1 at 100% power. The Senior Resident Inspector has been notified of this event. The MSIVs are shut with the steam generators (SG) discharging steam using the atmospheric dump valves. There is no primary to secondary leakage. Motor driven AFW pumps are running to maintain SG levels. RCS pressure remained above ECCS (Emergency Core Cooling System) discharge pressure.

ENS 51982 +/-
Where
Watts Bar Tennessee (NRC Region 2)
Reporting

10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge 10 CFR 50.72(b)(2)(iv)(B), RPS Actuation 10 CFR 50.72(b)(3)(iv)(A), System Actuation
LER:	05000391/LER-2016-004
Time - Person (Reporting Time:+-0.08 h-0.00333 days <br />-4.761905e-4 weeks <br />-1.09584e-4 months <br />)
Opened:	Michael Bottorff 16:22 Jun 5, 2016
NRC Officer:	Dong Park
Last Updated:	Jun 5, 2016
51982 - NRC Website Loading map... {"minzoom":false,"maxzoom":false,"mappingservice":"leaflet","width":"350px","height":"250px","centre":false,"title":"","label":"","icon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"zoom":6,"defzoom":14,"layers":["OpenStreetMap"],"image layers":[],"overlays":[],"resizable":false,"fullscreen":false,"scrollwheelzoom":true,"cluster":false,"clustermaxzoom":20,"clusterzoomonclick":true,"clustermaxradius":80,"clusterspiderfy":true,"geojson":"","clicktarget":"","imageLayers":[],"locations":[{"text":"\u003Cb\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003E\u003Ca class=\"mw-selflink selflink\"\u003EENS 51982\u003C/a\u003E - \u003Ca href=\"/Watts_Bar\" title=\"Watts Bar\"\u003EWatts Bar\u003C/a\u003E\n\u003C/p\u003E\u003C/div\u003E\u003C/b\u003E\u003Cdiv class=\"mw-parser-output\"\u003E\u003Cp\u003EReactor Trip and Eccs Actuation Caused by Turbine Governor Valve Failure\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 51982 - Watts Bar\n","link":"","lat":35.60199166666666,"lon":-84.7889388888889,"icon":"/w/images/c/ce/Tennessee_Valley_Authority_icon.png"}],"imageoverlays":null}
v • d • e

v t e Emergency Notification System
Watts Bar with 10 CFR 50.72(b)(2)(iv)(B), RPS System Actuation, 10 CFR 50.72(b)(3)(iv)(A), System Actuation, 10 CFR 50.72(b)(2)(iv)(A), System Actuation - ECCS Discharge
WEEKMONTHYEAR2024-07-08T19:21:00 [Table view]
[ENS list for Watts Bar]

@@ Line 16: / Line 16: @@
 | event date = 06/05/2016 12:27 EDT
 | last update date = 06/05/2016
-| title = Reactor Trip And Eccs Actuation Caused By Turbine Governor Valve Failure
+| title = Reactor Trip and Eccs Actuation Caused by Turbine Governor Valve Failure
 | event text = On June 5, 2016 at 1227 Eastern Daylight Time (EDT), Watts Bar Nuclear Plant (WBN) Unit 2 was in MODE 1 at approximately 12.5% power when a safety injection actuation occurred, followed by an automatic reactor protection system (RPS) trip.  Preliminary data suggests that the #1 high pressure turbine governor valve failed open causing a steam header pressure rate of decrease safety injection [SI] actuation signal.  As designed, the safety injection actuation caused both trains of the shared Emergency Gas Treatment System (EGTS) to align to Unit 2, requiring WBN Unit 1 to enter Technical Specification (TS) LCO 3.0.3 at 1227 [EDT].  Also as designed, Unit 1 annulus pressure momentarily increased, causing operation personnel to enter LCO 3.6.15 Condition B at 1240 [EDT].  At 1242 [EDT], after annulus pressure normalized, operations personnel exited LCO 3.6.15.  At 1245 [EDT], Operations personnel secured safety injection and Unit 2 was stabilized in MODE 3 at normal operating pressure and temperature.  By 1349 [EDT], Unit 1 Operations personnel had restored both trains of EGTS to standby readiness, and exited TS 3.0.3.  No primary safety barriers (RCS, containment and fuel clad) were challenged and no primary or secondary safety or relief valves actuated during the event.  The Unit 2 plant trip was uncomplicated and safety equipment operated as expected.
 Unit 2 is stable in Mode 3 at normal operating temperature and pressure, in normal shutdown power alignment. Unit 1 is stable in Mode 1 at 100% power.

v t e Unit 2
W-4-LP
Reactor critical	Critical
Scram	A/R
Before	Power Operation (13 %)
After	Hot Standby (0 %)

ENS 51982: Difference between revisions

Latest revision as of 20:45, 1 March 2018

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