Vesireaktori

Vesireaktori, often translated as "water reactor," is a term that can refer to several types of nuclear reactors. Most commonly, it describes a reactor that uses ordinary water as both a coolant and a neutron moderator. The vast majority of nuclear power reactors in operation worldwide fall into this category, specifically the Pressurized Water Reactor (PWR) and the Boiling Water Reactor (BWR) designs. In a PWR, water is kept under high pressure to prevent it from boiling in the reactor core. This hot, pressurized water then flows to a steam generator, where it transfers its heat to a secondary loop of water, producing steam to drive a turbine. In a BWR, the water is allowed to boil directly within the reactor core, with the steam produced then sent to the turbine. Both PWRs and BWRs are considered light water reactors, distinguishing them from heavy water reactors which use deuterium-oxide as the moderator and coolant. The term vesireaktori is primarily used in Finnish.