An electrical generation system that uses nuclear fission as its energy source. The fission method splits the atom, which generates a chain reaction of energy that heats water or gas to drive a turbine connected to an electrical generator.
More than 400 nuclear reactors are used in over 30 countries worldwide. In the U.S., the first reactor went online in 1969 in New York State. Although the U.S. has more nuclear reactors than any other country, after a partial meltdown of the Three Mile Island reactor near Harrisburg, Pennsylvania in 1979, people became fearful of nuclear generation. As a result, a fewer number of nuclear plants were built than might have otherwise been constructed. To date, there are more than 50 nuclear power plants in 28 states containing nearly a hundred reactors. A plant in Georgia began operation as recently as April 2024.
Given the huge energy demand from AI and crypto, nuclear reactors in sizes large and small are expected to make a comeback in the U.S. See
small modular reactor.
First Used for Bombs
The first fission reactor was designed to make the most powerful bomb ever created. Created in secrecy and known as the Manhattan Project, the nuclear fission "atom bombs" were used successfully in August 1945 over Hiroshima and Nagasaki. They ended the war in Japan, which was the final frontier in World War II. See
nuclear fusion.