At first glance, a nuclear power plant is very similar to a conventional coal-fired power plant. Both plants convert the energy stored in the fuel into heat. Water is heated and evaporated. The steam sets a turbine in rotation. A generator converts this rotary motion into electrical current.
The main difference between a coal-fired power plant and a nuclear power plant is the type and use of the fuel. In a coal-fired power plant, the coal is burned in a boiler; in a nuclear power plant, the energy stored in the uranium is obtained by means of nuclear fission and a controlled chain reaction. Enormous amounts of energy can thus be generated directly from the atomic nuclei. A single kilogramme of natural uranium can generate about 100,000 times more electricity than a kilogramme of lignite (i.e. about 100,000 kilowatt-hours). This will cover the total annual electricity demand of around 30 average private households in Germany.