The turbine-generator is the most important component in the power plant, other than the reactor and steam generator (if a PWR). Periodic inspection of the turbine and generator are scheduled every 5 or more years. The photos below illustrate what turbines look like when they are disassembled.
|Spare Low Pressure Turbine Rotor =>
The spare would be used if the installed rotor experiences abnormal conditions during operation. If a utility only has the installed rotor, a plant could be shutdown for many months if damage occurs. For example, one plant had electrical disturbances cause excessive vibration of the larger blades of the rotor and caused the plant to be shutdown for over 3 months for repairs.
|<== Disassembled Turbine Rotor
This photo below shows a large turbine rotor. During operation, the steam enters at the center and moves out both ways to turn the shaft. A rotor as this may weigh 50 tons.
|Disassembled Turbine Bearing ==>
Maintenance technicians are removing one of 8 or more turbine bearings during an outage. The bearings provide support for the long shaft. Operators monitor vibration and temperature during operation and ensure that the bearing is properly lubricated. Unusual conditions could result in the unit being shutdown.
Copyright © 1996-2004. Joseph Gonyeau. All rights reserved. Revised: March 15, 2001.