Assuring the integrity of large electrical machines in a power station refurbishment programme

A considerable number of the 500 MW unit fossil-fired power stations, built by the generating boards in the UK in the late 1960s and early 1970s, are at or approaching their design life of 20 years. There are powerful economic arguments for extending the life of these stations to 30 or 40 years, providing the cost of refurbishment to achieve this aim is not excessive. These arguments are being sharpened by the impending privatisation of the electricity supply industry, following which it is expected that a higher return on the capital invested in installed plant will be required. The authors discuss technical arguments for the refurbishment of large electrical machines in power stations. They highlight for operations and maintenance engineers, the criteria which should be applied in a refurbishment programme to decide whether an electrical machine needs to be left alone, refurbished or even replaced