Environmental Engineering Reference
A Different Kind
of Nuclear Power
Some radioisotopes are used as sources of energy for heating
purposes. No chain reaction or reactor is needed. The isotopes need
to be highly radioactive for this purpose, but not too radioactive.
They must decay slowly enough to be useful for a long time.
Plutonium-238 is often used for supplying heat in this way. Pu-
238 can serve as an energy source in special places—for example,
aboard spacecraft. In space,
the isotopes' radiation poses no
threat to living things. Each of
the two U.S. “rovers” that began
exploring Mars in 2004 has
eight Pu-238 heater units. (For
electricity, the rovers rely on
solar cells and batteries.)
Radiation provides some of the power for the
“rovers” exploring Mars.
does not have an endless amount of uranium, but it has a great
deal. In 2007, experts believed there was enough uranium to
last at least another 100 years. Building more efi cient reactors
will probably make the supply last much longer. Additional
nuclear fuel can be gotten from the reprocessing of spent fuel
and nuclear material from decommissioned weapons. Still
more fuel can be obtained from breeder reactors.