All power generation stations have a limited life span. With age power plants will become to expensive to operate and they will be permanently shut down. The most expensive stations to decommission are nuclear power plants.
Most parts of a nuclear power plant that are contaminated are very low levels. The surfaces can be cleaned by Laser light and released as clean. Equipment can now be salvaged for other uses and the metal can be recycled
Nuclear decommissioning is expensive due to the presence of radioactive material. The radioactive material must be decontaminated and disposed of at low-level waste burial facilities.
Current methods of decontamination include sandblasting, high-pressure water and chemicals. This produces significant amounts of secondary waste. These methods are so time consuming and expensive that most material is just shipped out for burial.