How is radioactive waste disposed of?

Which of the following problems are associated with nuclear power plants?

The most adverse effect of radioactive pollutant is

$A$ - Radiations emitted from radioactive waste cause mutations in living organisms.
$R$ - Radioactive waste is advantageous to human health.

High level radioactive waste can be managed in which of the following ways?

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.