Tuumareaktorite

Tuumareaktorite, known in English as nuclear reactors, are devices used to initiate and control a sustained nuclear chain reaction. The primary purpose of most nuclear reactors is to generate electricity through nuclear fission. In this process, heavy atomic nuclei, typically uranium, are split, releasing a significant amount of energy in the form of heat. This heat is then used to boil water, producing steam that drives turbines connected to generators, thereby producing electricity.

The core of a nuclear reactor contains nuclear fuel, usually enriched uranium in the form of pellets encased in fuel rods. Control rods, made of neutron-absorbing materials like cadmium or boron, are used to regulate the rate of the chain reaction by absorbing excess neutrons. A moderator, such as water or graphite, is also present to slow down the fast neutrons released during fission, making them more likely to cause further fission events. A coolant, often water, circulates through the reactor core to transfer the heat generated to the power conversion system and to prevent overheating.

Nuclear reactors can be classified based on their coolant, moderator, and neutron spectrum. Common types include pressurized water reactors (PWRs) and boiling water reactors (BWRs), both of which use water as both coolant and moderator. Other designs include heavy water reactors, graphite-moderated reactors, and fast breeder reactors, which can produce more fissile material than they consume. While electricity generation is the most common application, nuclear reactors also find use in research, isotope production for medical and industrial purposes, and propulsion systems for naval vessels and submarines.