bitumen
Gooey, black, high-sulfur, heavy oil extracted from tar sand and then upgraded to synthetic fuel oil. See tar sand.
breeder nuclear fission reactor
Nuclear fission reactor that produces more nuclear fuel than it consumes by converting nonfissionable uranium-238 into fissionable plutonium-239.
coal
Solid, combustible mixture of organic compounds with 30-98% carbon by weight, mixed with various amounts of water and small amounts of sulfur and nitrogen compounds. It forms in several stages as the remains of plants are subjected to heat and pressure over millions of years.
coal gasification
Conversion of solid coal to synthetic natural gas (SNG).
coal liquefaction
Conversion of solid coal to a liquid hydrocarbon fuel such as synthetic gasoline or methanol.
crude oil
Gooey liquid consisting mostly of hydrocarbon compounds and small amounts of compounds containing oxygen, sulfur, and nitrogen. Extracted from underground accumulations, it is sent to oil refineries, where it is converted to heating oil, diesel fuel, gasoline, tar, and other materials.
fissionable isotope
Isotope that can split apart when hit by a neutron at the right speed and thus undergo nuclear fission. Examples are uranium-235 and plutonium-239.
kerogen
Solid, waxy mixture of hydrocarbons found in oil shale rock. Heating the rock to high temperatures causes the kerogen to vaporize. The vapor is condensed, purified, and then sent to a refinery to produce gasoline, heating oil, and other products. See also oil shale, shale oil.
kilowatt (kW)
Unit of electrical power equal to 1,000 watts. See watt.
liquefied natural gas (LNG)
Natural gas converted to liquid form by supercooling to a very low temperature.
liquefied petroleum gas (LPG)
Mixture of liquefied propane (C3H8) and butane (C4H10) gas removed from natural gas and used as a fuel.
meltdown
The melting of the core of a nuclear reactor.
natural gas
Underground deposits of gases consisting of 50-90% by weight methane gas (CH4) and small amounts of heavier gaseous hydrocarbon compounds such as propane (C3H8) and butane (C4H10).
net energy
Total amount of useful energy available from an energy resource or energy system over its lifetime, minus the amount of energy used (the first energy law), automatically wasted (the second energy law), and unnecessarily wasted in finding, processing, concentrating, and transporting it to users.
nuclear energy
Energy released when atomic nuclei undergo a nuclear reaction such as the spontaneous emission of radioactivity, nuclear fission, or nuclear fusion.
nuclear fission
Nuclear change in which the nuclei of certain isotopes with large mass numbers (such as uranium-235 and plutonium-239) are split apart into lighter nuclei when struck by a neutron. This process releases more neutrons and a large amount of energy.
nuclear fusion
Nuclear change in which two nuclei of isotopes of elements with a low mass number (such as hydrogen-2 and hydrogen-3) are forced together at extremely high temperatures until they fuse to form a heavier nucleus (such as helium-4). This process releases a large amount of energy.
oil sand/tar sands
Deposit of a mixture of clay, sand, water, and varying amounts of a tarlike heavy oil known as bitumen. Bitumen can be extracted from tar sand by heating. It is then purified and upgraded to synthetic crude oil.
oil shale
Fine-grained rock containing various amounts of kerogen, a solid, waxy mixture of hydrocarbon compounds. Heating the rock to high temperatures converts the kerogen into a vapor that can be condensed to form a slow-flowing heavy oil called shale oil.
petrochemicals
Chemicals obtained by refining (distilling) crude oil. They are used as raw materials in manufacturing most industrial chemicals, fertilizers, pesticides, plastics, synthetic fibers, paints, medicines, and many other products.
radioactive waste
Waste products of nuclear power plants, research, medicine, weapon production, or other processes involving nuclear reactions.
shale oil
Slow-flowing, dark brown, heavy oil obtained when kerogen in oil shale is vaporized at high temperatures and then condensed. Shale oil can be refined to yield gasoline, heating oil, and other petroleum products. See kerogen, oil shale.
synfuels
Synthetic gaseous and liquid fuels produced from solid coal or sources other than natural gas or crude oil.
synthetic natural gas (SNG)
Gaseous fuel containing mostly methane produced from solid coal.
tailings
Rock and other waste materials removed as impurities when waste mineral material is separated from the metal in an ore.
watt
Unit of power, or rate at which electrical work is done.
hydraulic fracturing (fracking)
Using large amounts of water and chemicals under high pressure to fracture underground rock formations which releases the natural gas trapped within.