1. Maintenance objectives

1.1 Prevention of major accidents

The energy stored in the rotors is the source of the potentially serious consequences of major accidents involving high-power turbines (see ). The precautions taken at the turbine design, manufacture, operation and maintenance stages are designed to keep the probability of a major accident occurring to a very low level (around 10- ⁴ per unit per year). However, partial or total destruction of turbine-generator units does occasionally occur in the global fleet.

Major accidents can result from a variety of causes.

• Sudden...