Question

how is the radioactive energy removed from a nuclear power plants spent fuel rods?
the fuel rods are scrubbed clean, removing the energy.
the energy is only removed when it changes to a safer form.
the fuel rods are destroyed, removing the energy.

Explanation:

Radioactive energy in spent fuel rods is a result of radioactive decay. Radioactive decay is a natural process where unstable atomic nuclei lose energy by emitting radiation. This process continues until the radioactive material transforms into a more stable (safer) form. Scrubbing fuel rods does not remove radioactive energy as it is an inherent property related to nuclear structure and decay. Destroying fuel rods also does not eliminate the radioactive energy; the radioactive isotopes within would still undergo decay. Only when the radioactive substances decay and change to a safer (more stable) form is the 'radioactive energy' (in the sense of the hazardous radiation they emit) effectively 'removed' (as the new form emits less or non - hazardous radiation).

Answer:

The energy is only removed when it changes to a safer form.