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Unit 5 - Vocabulary of Nuclear Energy

Alpha Particle (Ray) a positively charged particle that is the nucleus of the helium atom; emitted during radioactive decay
Atom the smallest unit possessing the properties of an element; all matter is composed of atoms
Background Radiation radiation coming from naturally radioactive sources in the environment
Beta Particle (Ray electron emitted during radioactive decay. Negatively charged.
Boiling Water Reactor a nuclear reactor that uses water as a coolant and moderator; the steam produced can drive a steam turbine
Breeder Reactor A nuclear reactor that produces as well as consumes fissionable material, especially one that produces more fissionable material than it consumes
Chain Reaction In nuclear fission, a self-sustaining series reactions in which the release of neutrons from the splitting of one atom leads to the splitting of others
Containment A structure or system designed to prevent the accidental release of radioactive materials from a reactor
Core A reactor center
Fission Splitting of one atom into two smaller atoms producing energy; undergone by Uranium-235 when bombarded with neutrons
Fuel Pellets Small ceramic covered nuclear material, usually uranium dioxide, used in nuclear power plants. Most is the nonfissionable uranium-238 isotope, and about 3% is fissionable uranium-235.
Fuel Rod A protective metal tube containing pellets of fuel for a nuclear reactor
Gamma Ray High energy electromagnetic radiation emitted during radioactive decay and having an extremely short wavelength. Neutral particle.
Isotope Atoms of the same element having the same atomic number but different mass numbers; therefore different number of neutrons
Meltdown Severe overheating of a nuclear reactor core, resulting in melting of the core and escape of radiation
Millirem One thousandth (10-3) of a rem, which is unit of measure of ionizing radiation
Neutron Neutral particle present in nuclei of most atoms
Nuclear Energy the energy released by a nuclear reaction
Plutonium A naturally radioactive element, occurring in uranium ores and produced artificially by neutron bombardment of uranium. Its longest-lived isotope is Pu 244 with a half-life of 76 million years. Pu 239 is used as a reactor fuel and in nuclear weapons.
Pressurized Water Reactor a nuclear reactor that uses water as a coolant and steam turbine; but has two water systems
Radiation The particles and energy emitted from radioactive atoms
Radioactive Decay Emission of alpha, beta, or gamma rays by unstable isotopes
Radioactivity Spontaneous decay of unstable atomic nuclei accompanied by emission of ionizing radiation
Spent Fuel Reprocessing To cause to undergo special or additional processing before reuse
Turbine machine in which the kinetic energy of a moving fluid is converted into mechanical energy, caused by a rotating rotor
Uranium 235 a uranium isotope with mass number 235; capable of sustaining chain reactions