1. MAINTENANCE DEPARTMENT Presented by: John Argabright, Maint. Supervisor Muskingum River Plant APP Site Visit October 30 – November 4, 2006

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3. 3 MAINTENANCE APPROACH Proactive Critical Equipment Condition Assessment - Facility Health Report - Generating Availability Data System (GADS) - Experience With Similar Series Units - Equipment Age - Operating History - Manufacturer Recommendations - Electric Power Research Institute Studies (EPRI ) Economic Justification - Spend Optimization - Project Management Review Group (PMRG)

4. 4 MAINTENANCE APPROACH CONTINUED Outage Planning -Planning Horizon Facility Health Report – 10+ Years Long Range Plan – 10 Years - Outage Planning Frequency - Entire Unit - Major Components Duration Work Schedule

5. 5 MAINTENANCE APPROACH Budgeting 2007 Operations and Maintenance Non Outage - $10,100,000 Outage - $8,000,000 Plant Production Blanket ( Capital ) Non Outage Installation Projects - $1,400,000 Non Outage Removal Projects - $560,000 Outage Installation Projects - $6,000,000 Outage Removal Projects - $2,400,000

6. 6 TYPES of WORK Running Maintenance Forced Outage Scheduled Outage Predictive Maintenance Preventative Maintenance Corrective Maintenance

7. 7 UNIT 5 AVAILABILITY Effective Forced Outage Rate (EFOR) 2.43% Maintenance Outage Factor (MOF) 0.00% Capacity Factor (Cap. Fac.) 83.44% Equivalent Availability (Eq.Avail.) 93.30% Unavailability (Unavail.) 6.07% Unavailabilty Target(Unavail.Tar.) 7.81% Note: Values based on first half of 2006 performance data

8. 8 UNIT 5 MAINTENANCE ORGANIZATION 1- Mechanical Maintenance Supervisor 2 - Welders 1 - Machinist 3 - Mechanics 1- Instrument/Control/Electrical Supervisor 5 - ICE Senior Technicians 2 - ICE Junior Technicians

9. 9 MAINTENANCE GOALS Anticipate equipment failure and repair or replace before it becomes a liability Apply best practices techniques Restore equipment to expected capacity and performance level Focus resources for best results Maintenance and capital expenditures Optimize planned outage time

10. 10 EFFICIENCY RESTORATION Turbine-generator overhaul cycle HP / 1 st RH / 2 nd RH / LP – 8 / 8 / 8 /15 years 1 st and 2 nd RH turbine overhaul in 2003 regained 13 Kcal/kWh ( 50 BTU/kWh ) Cooling tower rebuild planned for 2008 Air heater baskets replaced in 2003

11. 11 EFFICIENCY RESTORATION ( CONTINUED FROM PREVIOUS PAGE ) Condenser tubes cleaned every 6 years using scrapers.The cooling tower circulating water is chemically treated to prevent fouling. Applied Irathane coating on turbine exhaust hood to condenser expansion joints to reduce air inleakage in 1998. Retube main turbine condenser in 1998 due to tube leakage. Replaced high pressure heaters in 1995 due to leakage.

12. 12 EFFICIENCY RESTORATION UNITS 1, 2, 3 and 4 Unit 3 LP turbine overhaul in 2005 regained 15 kcal / kWh ( 60 BTU / kWh ) Unit 2 HP / RH turbine overhaul in 2004 regained 19kcal /kWh ( 75 BTU / kWh ) Main condensers cleaned annually with scraper plugs due to using river water. Retubed units 1 and 2 crossover feedwater heaters in 1998 due to tube failures.

13. 13 EFFICIENCY IMPROVEMENT Units 1, 2, 3 and 4 Extended sootblower lance tube length using RA330 material to increase boiler cleanliness. 8 kcal / kWh (30 BTU / kWh) Installed flexible hot side air heater seals Units 1 and 2 - 2.5 kcal / kWh (10 BTU / kWh) Units 3 and 4 – 7 kcal / kWh (25 BTU/kWh) Unit 5 Use synthetic oil in pulverizer roll wheels to allow pulverizer outlet temperature to be raised from 66 C to 79 C (150 F to 175 F) for a gain of 3 kcal / kWh (10 BTU / kWh )