Lättvattenlosningar

Lättvattenlösningar, often translated as light water solutions or light water reactors, refers to a type of nuclear reactor that uses ordinary water as both a coolant and a neutron moderator. This is in contrast to heavy water reactors, which use deuterium oxide (heavy water) for these purposes. The vast majority of the world's nuclear power plants are light water reactors, making them the most common design globally.

There are two primary designs of light water reactors: Pressurized Water Reactors (PWRs) and Boiling Water Reactors (BWRs). In a PWR, the cooling water is kept under high pressure to prevent it from boiling as it circulates through the reactor core. This hot, high-pressure water then flows to a steam generator, where it transfers its heat to a separate loop of water, producing steam that drives a turbine. In a BWR, the water is allowed to boil directly within the reactor core. The steam produced then flows directly to the turbine.

Light water reactors are favored for their relative simplicity, established safety record, and the widespread availability of ordinary water. The fuel used is typically enriched uranium, meaning the concentration of the fissile isotope uranium-235 has been increased. The moderator slows down fast neutrons released during fission, making them more likely to cause further fission reactions and sustain the chain reaction.