The Radioactive Boy Scout by Ken Silverstein

Author:Ken Silverstein
Language: eng
Format: epub
ISBN: 9781588363565
Publisher: Random House Publishing Group
Published: 2004-03-02T00:00:00+00:00

Chapter 6

How Nuclear Enthusiasts Planned to Solve the Energy Crisis: A Brief History of the Breeder Reactor

Plutonium will be the fuel of the future [and its value] may someday make it a logical contender to replace gold as the standard of our monetary system.

—Glenn Seaborg, chairman of the Atomic Energy Commission, 1968

A conventional nuclear-power plant operates in essentially the same manner as a power plant that runs on fossil fuels like coal or oil. Heat boils water to make steam, which turns a turbine generator. “The only difference is the source of the heat,” explained Atoms to Electricity, a booklet put out by the Department of Energy. “Whereas coal and oil are burned directly, a sustained atomic chain reaction called fission generates heat in a nuclear plant.”

There are several dozen radioactive elements, but only a few isotopes with particularly unstable nuclei can undergo fission: uranium-235, plutonium-239, and uranium-233, the last two of which are man-made. Fission occurs when a neutron (or other high-speed particle) is fired at and penetrates the nucleus of an isotope.

For example, the nucleus of an atom of U-235, the most easily fissionable isotope because it has unusually large atoms that are highly volatile, contains 92 protons and 143 neutrons. When a U-235 atom is hit by and absorbs a neutron, it splits in two—fissions—and releases energy in the form of heat, as well as a few additional neutrons. These neutrons are in turn absorbed by other U-235 atoms, beginning the process again. In theory, you need to split only a single U-235 atom to create a chain reaction. The neutrons from the first split will continue to split other atoms, which will split more and more in geometric progression. If left unchecked, a chain reaction will lead to an uncontrolled meltdown.

Unlike its sister isotope, U-238 (92 protons and 146 neutrons)—which comprises over 99 percent of the content of pure uranium ore—is not itself fissionable. That’s because it has three more neutrons in its nucleus than U-235 and tends to reflect additional neutrons rather than absorb them. U-238, though, is considered “fertile.” As discovered by Glenn Seaborg, when bombarded with neutrons U-238 is transformed into U-239. The latter decays by emitting beta rays and is transformed into a man-made radioactive element that Seaborg and his team called neptunium—after the planet Neptune, a name picked because the element contains in its nucleus one more proton than uranium, which of course had been named for Uranus, the planet next closest the sun. Neptunium is unstable and spontaneously ejects a beta particle, thereby forming plutonium (named for the planet Pluto), with ninety-four protons. Plutonium, which is fissionable, can be used as fuel for a nuclear reactor.

Nuclear-power plants are built to various designs, but the core, where heat is produced, generally comprises four basic components. The first is the fuel, usually pellets of uranium encased in tubes. Firing neutrons at these fuel rods produces fission. The second is the moderator, which is used to slow down the neutrons. Manhattan Project scientists

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