Which of the following is a major source of radioactive pollution?

Which of the following statement$(s)$ is/are correct?
$(i)$ Nuclear energy is a non-polluting way of generating electricity.
$(ii)$ Radioactive waste leakage incidents occurred at Three Mile Island and Chernobyl.
$(iii)$ Prolonged exposure to radioactive waste can cause cancer.
$(iv)$ Radioactive waste is recyclable.
$(v)$ High doses of radiation are lethal.

The most adverse effect of radioactive pollutant is

$I.$ Radiation from nuclear waste is $A$ at a very high rate.
$II.$ At low doses,radiation causes $B$.
Complete the given statement by choosing the appropriate option for $A$ and $B$.

One of the most dangerous radioactive pollutants to $Homo$ $sapiens$ is:

Wastes may be sealed in concrete-filled drums and discharged to a depth of about $500 \;m$. This specific statement is true for