Video Transcript
Which of the following most
correctly describes the difference between the radioactive materials used as fuel in
nuclear power stations and the radioactive waste produced by these power
stations? (A) The radioactive materials used
as fuel in nuclear power stations release energy slower than the radioactive waste
produced by these power stations. (B) There is no difference between
the radioactive materials used as fuel in nuclear power stations and the radioactive
waste produced by these power stations. (C) The radioactive materials used
as fuel in nuclear power stations release energy faster than the radioactive waste
produced by these power stations.
Let’s first remember that
radioactive materials are used as fuel in a nuclear power plant. When the unstable atomic nuclei in
the fuel decay, these nuclei change to become nuclei of different elements or of
different isotopes of an element. Unstable atoms of some isotopes of
some elements can be used as nuclear fuel, but some other unstable atoms of isotopes
cannot be used for nuclear fuel.
Materials that contain nonuseful
unstable atoms can be radioactive waste materials. As some unstable atoms are useful
for nuclear fuel and some are not, there must be some difference between radioactive
materials that contain the useful unstable atoms and those that contain the other
nonuseful atoms. We must then reject option (B),
which says that the radioactive materials used for fuels are no different to those
which are radioactive waste materials.
The other options given in the
question both say that nuclear fuel materials are different to nuclear waste
materials, and that the difference is due to how fast these materials release
energy. Recall that in a nuclear power
plant, energy is transferred by nuclear radiation to thermal energy of water to boil
the water. If a radioactive material releases
energy slowly, it will take longer to boil water than a radioactive material that
releases energy quickly.
What makes a nuclear fuel material
useful as fuel is that it releases energy quickly, so that it can boil water
quickly. So, option (A) is not correct,
because radioactive fuel materials do not release energy more slowly than
radioactive waste. The correct option is (C). Radioactive materials used as fuel
release energy faster than the radioactive waste produced in a nuclear power
plant.
