ML061670325

06/14/2006 Public Meeting Licensee Presentation Slides for Quad Cities End-of-Cycle Plant Performance Annual Assessment

ML061670325
Person / Time
Site:	Quad Cities
Issue date:	06/14/2006
From:	Tulon T Exelon Generation Co
To:	Office of Nuclear Reactor Regulation
References
Download: ML061670325 (23)

Text

1 Quad Cities Station Update End-of-Cycle Meeting June 14, 2006 Tim Tulon Site Vice President 2 Topics:*Extended Power Uprate

-The problem-The fix*Radiation Reduction 3 Extended Power Uprate Completed

• 17% Power Uprate

-Produce 912 megawatts electric

• NRC approval in December 2001

• Initial EPU operation:

-Unit 2 in March 2002

-Unit 1 in December 2002Objective -Increase total generation output on both reactors 4 The Problem Increased steam flow Increased acoustic loads Increased Steam Dryer loads Increased steam line piping vibrations ERV actuator damage Steam Dryer cracks 5 Finding the Source

• Unprecedented testing and analysis determined the source of the vibration to the 'standpipes' on the steam lines where the valve attach to the piping.

-The length of the standpipe was increased to reduce the

acoustics inside the pipe. ---

Similar to tuning a pipe organ, or blowing over the top of a soda bottle.

ERV Standpipe 6 State-of-the-Art Testing and Analysis Conducted to Validate Vibration Source

• Testing conducted in six states

• Scale models of actual Quad Cities reactor and piping utilized

• Shaker table testing conducted to duplicate actual vibration levels 7 Actions Taken to Correct Vibration Problem

• Installed New Steam Dryers

-More robust

• Installed Acoustic Side Branch Modification

-Retune the steam system

• Installed Upgraded Valve Actuators

-'Hardened' the actuator 8 New Steam Dryers

• Both Quad Cities steam dryers were replaced in early 2005 with a more robust

design:-Increased stress margins on steam dryers

-Instrumentation provided validation of design load

-Strain gauges provided stress data for analytical purposes 9 2006 Electromatic Relief Valve Upgrade

• Late 2005 issues were discovered with the actuators on the Electromatic Relief Valves (ERVs) due to vibration.

• The ERV actuators have now been replaced with more robust design:-Several ERV actuator replacement options evaluated. New General Electric design proved to

be most rigorous as validated with shaker table tests.

10 Shaker Table TestingERV Actuator TestingERV Testing 11New ERV Actuator -vs-Previous New GE Design Previously Installed Design 12 2006 Acoustic Side Branch Modification Removing the Source of the Vibrations 13 2006 Acoustic Side Branch Modification

• Objectives:

-Reduce dryer loading to increase stress margin for long-term operation of dryer

-Reduce overall MSL vibrations impacting ERV actuators and other attached main steam components

-Retuned the steam system 14 How Does the ASB Work?

The addition of the ASB increases the effective length of the ERV/SV standpipe, thereby

decreasing the frequency of the acoustic standing wave. It is similar to a muffler, the ASB

'tunes' the steam flow to reduce vibrations in the piping.

15 Acoustic Side Branch Mod Main Steam Safety Valve Electromatic Relief Valve ASBs 16 Unit 2 Startup Testing RESULTS:*EPU Flow Induced Vibration (FIV)

Reduced to ~ 50% Original Licensed Thermal Power Levels.-Meaning: today steam piping vibration levels at full-EPU power is approximately 50% than when the plant was first put in to commercial operation in 1972.

17 Typical Accelerometer Data ResultsQ2R18 Accelerometer TrendsTarget Rock Inlet Flange - X 00.050.10.150.20.250.30.350.4050010001500200025003000Core Thermal Power, MWtAcceleration, grms3A Target Rock Inlet Flange X1Historical (pre-ASB) EPU ValueHistorical (pre-ASB) OLTP Value3A Target Rock Inlet Flange X23A Target Rock Historical - X Last May w/o ASBs With ASBs 18 Conclusions

• Main Steam Line (MSL) vibrations are reduced

• The ASB modification effectiveness has been confirmed. This adds significant safety margin and substantially increased vibration tolerance to the steam dryer structural integrity and other

main steam line components.

• Both units can operate safely and reliably at EPU power levels.

ASBs Work!

19 Radiation Exposure Efforts 20 Station Has Taken Aggressive Actions to Reduce Radiation Exposure

• Chemical decontamination of reactor piping on both units

• Replacement of turbine blades which contained high sources of Cobalt 60

• Installed permanent lead shielding in several high radiation areas of the plant

• Improved worker training / increased awareness through individual dose goals 21 486.0 436.3 336.2 190.0 162.00 rem100 rem 200 rem300 rem400 rem500 rem600 remQ2R16 (2002)Q2R17 (2004)Q2R18 (2006)Q2R18minus ASB / DryerQ2R19 projected (2008)Dose (person-rem)

Red line represents 150 rem -our path to full INPO points and industry best dose performance Red line represents 150 rem -our path to full INPO points and industry best dose performance U2 Outage Dose Reduction Trend Industry Best 22 Where Are We GoingINPO Collective Radiation Exposure Point Performance 6.2 9.7 10.00.00.0 0 points 1 points 2 points 3 points 4 points 5 points 6 points 7 points 8 points 9 points 10 pointsCurrent200720082009Full Points Industry Best Red line represents 150 rem -our path to full INPO points and industry best dose performance Red line represents 150 rem -our path to full INPO points and industry best dose performance 23 Questions?