Question

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

Explanation:

Radioactive energy in spent fuel rods is not removed by scrubbing or destroying the rods. Radioactive materials decay over time, and the energy associated with radioactivity is only truly "removed" when the radioactive isotopes undergo decay processes (such as alpha, beta, or gamma decay) and transform into more stable (safer) forms.

Answer:

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