4. Plant life and renewal

Most of the water-fired power plants built around the world over the last three decades have been designed for a service life of 40 years. The actual lifespan will depend on many factors, including technical, regulatory and economic factors:

• technical, as some components are very difficult to replace;

• This is because safety requirements increase over time, and the safety authority may consider that there is too great a gap between the safety baseline (i.e. the set of safety rules complied with by the facility) of the existing facility and the requirements for a new facility;

• economic, insofar as maintenance or safety upgrading costs become too high, but also if electricity sales conditions do not allow for sufficient profitability.

For example,...