Nuclear energy for heat and electrical energy: Climate-friendly, adequate, but questionable

Around 1950, nuclear energy already had a share of 15-18% in the electricity supply, but this decreased to 10% for reasons of various kinds, such as safety, disposal of nuclear waste, but above all because of the enormous costs during construction. Nevertheless, their share of energy generation remains higher than that of wind and solar energy or photovoltaics, but the energy development is incomparably higher. Almost all nuclear power reactors worldwide are pressurized water reactors, with two separate circuits: In the first circuit, the water in the "bath furnace" is heated to about 300 degrees Celsius with the help of the nuclear reaction. With hot steam in the boiler, a steam turbine can then be put to work, which turns a power generator. Because of the maximum temperature to which the nuclear reactor is limited for safety reasons, the thermal efficiency remains at 33 to 40%, i.e., below that of a modern coal-fired power plant. The disposal of nuclear waste remains an open problem, even though there are numerous, promising approaches.