ML093020671
| ML093020671 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 10/22/2009 |
| From: | Progress Energy Carolinas |
| To: | NRC/RGN-II |
| Shared Package | |
| ML093020640 | List: |
| References | |
| Download: ML093020671 (24) | |
Text
Brunswick Nuclear Plant Emergency Diesel Generators NRC Region II Visit October 22, 2009
Agenda l AC Power Reliability l EDG Historical Performance l EDG Performance Indicators l EDG #4 Governor l Organizational Lessons and Actions from Recent Events 2
AC Power Reliability 3
Completed Actions Installed new 230 kV supply breakers for SATs Installed new Unit output breakers Replaced SWYD CCVTs & Lightning Arrestors Installed new local 230 kV capacitor banks for voltage support on Unit 2 Installed new Main Transformers - Outfitted with continuous gas monitoring instrumentation Improved material condition of spare SAT Replaced sudden pressure relays Replaced no load disconnect switches Improved PMs on Iso-Phase and Non-Seg Bus Inspected Non-Seg Bus flex links Established standard preventive maintenance program for buses Installed permanent SAMA diesel generators on Unit 2 Planned Actions Install new local 230 kV capacitor banks for voltage Support on Unit 1 Install permanent SAMA diesel generators on U1 Unit Auxiliary Transformer (UAT) Replacement Replace remaining transmission line breakers Replace Line Insulators at a rate of ~150 sets per year during each unit Completed Actions Replaced 2 transmission line breakers Replaced 145 poles and 341 insulator sets Revised Transmission Interface Agreement to specify plant involvement/coordination of work activities Under Evaluation Replace SATs w/auto load tap changing transformers Upgrade 2/3 logic for Aux Transformer
Emergency Power Reliability 4
Installed two backup diesel powered generators (SAMA diesel generators) to power the 125 VDC batteries Improved CDF by 68% on Unit 1 and 66% on Unit 2
5 EDG Historical Performance 2007 Reliability Study
w Operations w Maintenance w Engineering w Technical Training 2007 Reliability Study 6
w Licensing w Procurement w Industry Representative w Vendor Representative
- Multi-discipline team assembled to review EDG issues and develop short and long term action plan
- INPO Assist
l MSPI Reliability data l
Vendor Input/Industry OE l
Maintenance Rule Functional Failures, 2000-2006 l
BNP Equipment Reliability List l
EDG Planned and Unplanned Out Of Service (OOS) times, 2003-2006 l
EDG Corrective Work Orders, 2003-2006 2007 Reliability Study Inputs Used in Analysis 7
l EDG Material Costs, 2003-2006 l
EDG Self Assessment &
Benchmarks, 2003-2006 l
EDG NRC Findings, 2003-2006 l
EDG Nonconformances l
EDG items on Long Range Plan l
System Engineer brainstorming sessions
EDG Actions Action 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 EDG #2 exhaust bellows Allen Bradley relays Jacket Water TCVs SAMG DGs Capacitor leak EDG PM evaluations Ultra Low Sulfur Fuel Latent design issues Human perform issues High qual potentiometers GEMCO control switches Replace EDG #1 bearing Collector ring Starting air config/quality Exciter/voltage regulator Governor upgrade Piston replacement (est) 8 Completed Working Scheduled
EDG Performance Indicators 9
Brunswick Unit 1 Emergency AC Power System NRC Performance Indicator - MSPI (36 Months)
September 2009 Status: 87% Margin Remaining in Green 10
Brunswick Unit 2 Emergency AC Power System NRC Performance Indicator - MSPI (36 Months)
September 2009 Status: 86% Margin Remaining in Green 11
4 3
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2004 2005 2006 2007 2008 2009 BNP Ind (Aug)
Avg/EDG Avg/EDG
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ft _______ 1"' _____ _
Emergency Diesel Generators INPO Unavailability 13
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Planned -
Unplanned
EDG #4 Governor 14
EDG #4 Governor l
EDG #4 removed from service for 6 year preventive maintenance:
w 4.5 days planned unavailability w Commenced 7 day LCO on both units l
During Post Maintenance Testing, EDG #4 failed to start due to governor failure.
l Governor testing, tuning, support component replacement, and oil flushing occurred for the replaced governor - resulting in the expiration of the LCO prior to completing testing.
15
EDG #4 Failure Analysis l
FME on Pilot Plunger restricted movement l
Two possible sources for particles:
w Internal Wear Particles w External Source (FME) l Factors for wear of internal parts w Oil analysis did not indicate abnormal wear of internal parts w Inspection of internal parts during disassembly did not indicate wear l
Potential Source(s) of FME:
w Vendor maintenance on Pilot assembly without flush w On-site testing/installation or oil addition/flushing activities.
16
Evaluation of Governor 17 Pilot Valve Plunger Compensation Land (FME binding location)
Evaluation of Governor 18 Pilot Valve Plunger Centering Spring Compensation Land
FME on Pilot Plunger 19
Organizational Lessons and Actions from Recent Events (2007-2009) l Technical Rigor w Technical Task Risk/Rigor procedure w Engineering Product Quality Procedure revision w Trending and Monitoring l
Post Maintenance Testing Process Improvements w PMT specificity based upon safety related function 20
Organizational Lessons and Actions from Recent Events (2007-2009) l Work Management w Sensitivity to risk significant work w Outage Control Center Use w Readiness Reviews l
Parts Quality - Interim Actions (pending permanent corrective actions) w FME requirements for vendors in Purchase Orders/Contracts w Increased vendor surveillance w Interim EDG Spare Parts controls -
inspection/testing/FME inspections w Review near term EDG maintenance plans 21
Organizational Lessons and Actions from Recent Events (2007-2009) l EDG Reliability Review Update w Validate Corrective actions taken from events since 2007 are bounding and comprehensive w Review problems/failures since 2007 w Review Industry Operating Experience since 2007 w Benchmark other utility EDG Reliability plans w Revise as needed near/long-term reliability improvement strategy 22
Organizational Lessons and Actions from Recent Events (2007-2009) l EDG Maintenance Strategy Improvements:
w Near Term - Evaluate options to address extension of 7 day LCO:
u Reduces overall unavailability to complete work u Improved efficiency of work planning w Longer Term - Evaluate options to address long duration LCO for EDG major overhaul/repairs u Additional on-site emergency AC capability u AC distribution alignment w Common Mode Failure Strategy for Maintenance implementation 23
Questions?
24