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 Enclosure 2
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
Enclosure 2
AC Power Reliability Completed Actions Completed Actions Installed new 230 kV supply breakers for SATs Replaced 2 transmission line breakers Installed new Unit output breakers Replaced 145 poles and 341 insulator sets Replaced SWYD CCVTs & Lightning Arrestors Revised Transmission Interface Agreement to specify Installed new local 230 kV capacitor banks for plant involvement/coordination of work activities voltage support on Unit 2 Planned Actions Installed new Main Transformers - Outfitted with Install new local 230 kV capacitor banks for voltage continuous gas monitoring instrumentation Support on Unit 1 Improved material condition of spare SAT Install permanent SAMA diesel generators on U1 Replaced sudden pressure relays Unit Auxiliary Transformer (UAT) Replacement Replaced no load disconnect switches Replace remaining transmission line breakers Improved PMs on Iso-Phase and Non-Seg Bus Replace Line Insulators at a rate of ~150 sets per year Inspected Non-Seg Bus flex links during each unit Established standard preventive maintenance Under Evaluation program for buses Replace SATs w/auto load tap changing transformers Installed permanent SAMA diesel generators on Unit 2 Upgrade 2/3 logic for Aux Transformer 3
Enclosure 2
Emergency Power Reliability 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 4
Enclosure 2
EDG Historical Performance 2007 Reliability Study 5
Enclosure 2
2007 Reliability Study
- Multi-discipline team assembled to review EDG issues and develop short and long term action plan w Operations w Licensing w Maintenance w Procurement w Engineering w Industry Representative w Technical Training w Vendor Representative
- INPO Assist 6
Enclosure 2
2007 Reliability Study Inputs Used in Analysis l MSPI Reliability data l EDG Material Costs, 2003-2006 l Vendor Input/Industry OE l EDG Self Assessment &
l Maintenance Rule Functional Benchmarks, 2003-2006 Failures, 2000-2006 l EDG NRC Findings, 2003-2006 l BNP Equipment Reliability List l EDG NCRs, 2003-2006 l EDG Nonconformances l EDG Planned and Unplanned l EDG items on Long Range Plan Out Of Service (OOS) times, 2003-2006 l System Engineer brainstorming sessions l EDG Corrective Work Orders, 2003-2006 7
Enclosure 2
EDG Actions Action 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 EDG #2 exhaust bellows Allen Bradley relays Completed Jacket Water TCVs Working SAMG DGs Scheduled 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 Enclosure 2
EDG Performance Indicators 9
Enclosure 2
Brunswick Unit 1 Emergency AC Power System NRC Performance Indicator -MSPI (36 Months)
September 2009 Status: 87% Margin Remaining in Green 10 Enclosure 2
Brunswick Unit 2 Emergency AC Power System NRC Performance Indicator -MSPI (36 Months)
September 2009 Status: 86% Margin Remaining in Green 11 Enclosure 2
4 3
2 1
o ...j£--
2004 2005 2006 2007 2008 2009 BNP Ind (Aug) Avg/EDG Avg/EDG
~ ft _______ 1"' _____ _
12 Enclosure 2
Emergency Diesel Generators INPO Unavailability 0.025 ............................................................................................................................................................................................................................................................. 0.005
"'C
"'C Q) 0.02 ......................................................................................................................................................................................................................................................... 0.004 ~
c: c:
c: ro ro ~
~ 0.015 .......................................................................................................................................................................................................................................................... 0.003 :5
..c Q) ro ..c ro 0.01 .................................................................................................................................................................................................................................... 0.002 :
ro c: >
ro
~ c:
- .:R 0.005 ..................................................................................,. . .."",........................................................................................................................................................ 0.001 ~
o o o
- Planned - Unplanned 13 Enclosure 2
EDG #4 Governor 14 Enclosure 2
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 Enclosure 2
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 Enclosure 2
Evaluation of Governor Compensation Land (FME binding location)
Pilot Valve Plunger 17 Enclosure 2
Evaluation of Governor Pilot Valve Plunger Compensation Land Centering Spring 18 Enclosure 2
FME on Pilot Plunger 19 Enclosure 2
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 Enclosure 2
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 Enclosure 2
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 Enclosure 2
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 Enclosure 2
Questions?
24 Enclosure 2