A nuclear reactor core is the portion of a nuclear reactor containing the nuclear fuel components where the nuclear reactions take place and the heat...

A nuclear meltdown (core meltdown, core melt accident, meltdown or partial core melt) is a severe nuclear reactor accident that results in core damage...

created in a nuclear reactor core during a nuclear meltdown accident. Resembling lava in consistency, it consists of a mixture of nuclear fuel, fission...

pressurized water reactor (PWR) is a type of light-water nuclear reactor. PWRs constitute the large majority of the world's nuclear power plants (with...

The small modular reactor (SMR) is a class of small nuclear fission reactor, designed to be built in a factory, shipped to operational sites for installation...

Thermal-neutron reactors are the most common type of nuclear reactor, and light-water reactors are the most common type of thermal-neutron reactor. There are...

A boiling water reactor (BWR) is a type of nuclear reactor used for the generation of electrical power. It is the second most common type of electricity-generating...

A nuclear reactor coolant is a coolant in a nuclear reactor used to remove heat from the nuclear reactor core and transfer it to electrical generators...

Reactor (LWBR) core installed at the Shippingport Atomic Power Station. The reactor of this power plant was designed to accommodate different cores....

reactor") is a class of graphite-moderated nuclear power reactor designed and built by the Soviet Union. It is somewhat like a boiling water reactor as...

Generation III reactors, or Gen III reactors, are a class of nuclear reactors designed to succeed Generation II reactors, incorporating evolutionary improvements...

Generation IV (Gen IV) reactors are nuclear reactor design technologies that are envisioned as successors of generation III reactors. The Generation IV International...

pebble-bed reactor (PBR) is a design for a graphite-moderated, gas-cooled nuclear reactor. It is a type of very-high-temperature reactor (VHTR), one...

A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. These reactors can be fueled with more-commonly available...

releasing both energy and free neutrons. A reactor consists of an assembly of nuclear fuel (a reactor core), usually surrounded by a neutron moderator...

A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction. Nuclear reactors are used at nuclear power plants for electricity...

A molten-salt reactor (MSR) is a class of nuclear fission reactor in which the primary nuclear reactor coolant and/or the fuel is a mixture of molten salt...

operation of the CANDU design is similar to other nuclear reactors. Fission reactions in the reactor core heat pressurized water in a primary cooling loop...

advanced boiling water reactor (ABWR) is a Generation III boiling water reactor. The ABWR is currently offered by GE Hitachi Nuclear Energy (GEH) and Toshiba...

heavy-water reactor (AHWR) or AHWR-300 is the latest Indian design for a next-generation nuclear reactor that burns thorium in its fuel core. It is slated...

to the environment, or a reactor core melt. The prime example of a "major nuclear accident" is one in which a reactor core is damaged and significant...

Low-Power Reactor Number One, also known as SL-1, initially the Argonne Low Power Reactor (ALPR), was a United States Army experimental nuclear reactor in the...

disaster began on 26 April 1986 with the explosion of the No. 4 reactor of the Chernobyl Nuclear Power Plant near the city of Pripyat in northern Ukraine, near...

The advanced gas-cooled reactor (AGR) is a type of nuclear reactor designed and operated in the United Kingdom. These are the second generation of British...

The BN-800 reactor (Russian: реактор БН–800) is a sodium-cooled fast breeder reactor, built at the Beloyarsk Nuclear Power Station, in Zarechny, Sverdlovsk...

In applications such as nuclear reactors, a neutron poison (also called a neutron absorber or a nuclear poison) is a substance with a large neutron absorption...

fall onto the reactor hall, causing a nuclear meltdown. On 26 April 1986, reactor No. 4 suffered catastrophic meltdown resulting in a core explosion and...

The Lucens reactor was a 6 MW experimental nuclear power reactor built next to Lucens, Vaud, Switzerland. After its connection to the electrical grid...

to a plenum that directs the air into the nuclear reactor core. An exchange takes place where the reactor is cooled, but it then heats up the same air...

A core catcher is a device provided to catch the molten core material (corium) of a nuclear reactor in case of a nuclear meltdown and prevent it from escaping...