ENS 42610: Difference between revisions

v t e ENS Event
21:00 May 30, 2006
Title	Manual Reactor Trip on High Turbine Vibration
Event Description	At approximately 1700 hours0.0197 days <br />0.472 hours <br />0.00281 weeks <br />6.4685e-4 months <br /> on May 30, 2006, with Watts Bar Nuclear Plant Unit 1 operating normally at 100% power, main turbine vibration increased to a value above the procedure limit and reactor operators manually tripped the reactor in accordance with site procedure requirements. All control rods inserted and the auxiliary feedwater system automatically actuated per design. No other significant equipment issues were identified and the reactor was stabilized in mode 3. This event is reportable under 10 CFR 50.72(b)(2)(iv)(B) for the manual reactor trip (4-hour report) and under 10 CFR 50.72(b)(3)(iv)(A) for the RPS and AFW actuations (8-hour report). Watts Bar had been monitoring indications of slightly elevated turbine vibration on the main turbine, but the reason for the increase above the procedure limit of 14 mils is not known at this time. TVA will be investigating the cause of the increased vibration to make necessary repairs before turbine startup. Decay heat is being removed by dumping steam to the main condenser. No safety or relief valves lifted. The licensee notified the NRC Resident Inspector. * * UPDATE FROM LICENSEE (R. CREWS) TO M. RIPLEY 0020 EDT 06/02/06 * * * As a result of the initial assessment of the turbine vibration discussed above, TVA has identified damage to the turbine end of the 'C' low pressure turbine. This is consistent with the initial indications of high vibration on the number 7, 8 and 9 bearings and not thought to be associated with previous condition monitoring of the number 11 bearing. Assessment and repair of secondary plant components damaged in the transient are in progress. The licensee will notify the NRC Resident Inspector. Notified R2DO (C. Ogle)

ENS 42610 +/-
Where
Watts Bar Tennessee (NRC Region 2)
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:+-0.97 h-0.0404 days <br />-0.00577 weeks <br />-0.00133 months <br />)
Opened:	Dana White 20:02 May 30, 2006
NRC Officer:	Mark Abramovitz
Last Updated:	Jun 2, 2006
42610 - 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 42610\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\u003EManual Reactor Trip on High Turbine Vibration\n\u003C/p\u003E\u003C/div\u003E","title":"ENS 42610 - 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
WEEKMONTHYEAR2025-07-13T18:18:00 [Table view]
[ENS list for Watts Bar]

@@ Line 16: / Line 16: @@
 | event date = 05/30/2006 17:00 EDT
 | last update date = 06/02/2006
-| title = Manual Reactor Trip On High Turbine Vibration
+| title = Manual Reactor Trip on High Turbine Vibration
 | event text = At approximately 1700 hours on May 30, 2006, with Watts Bar Nuclear Plant Unit 1 operating normally at 100% power, main turbine vibration increased to a value above the procedure limit and reactor operators manually tripped the reactor in accordance with site procedure requirements.  All control rods inserted and the auxiliary feedwater system automatically actuated per design.  No other significant equipment issues were identified and the reactor was stabilized in mode 3.
 This event is reportable under 10 CFR 50.72(b)(2)(iv)(B) for the manual reactor trip (4-hour report) and under 10 CFR 50.72(b)(3)(iv)(A) for the RPS and AFW actuations (8-hour report).

v t e Unit 1
W-4-LP
Reactor critical	Critical
Scram	Yes, Manual Scram
Before	Power Operation (100 %)
After	Hot Standby (0 %)

ENS 42610: Difference between revisions

Latest revision as of 21:18, 1 March 2018

Navigation menu

ENS 42610: Difference between revisions

Latest revision as of 21:18, 1 March 2018

Navigation menu

Search