The chemical which causes damage to $WBC$, bone marrow, spleen, lymph nodes, and lungs is

The first major problem associated with nuclear energy is accidental leakage. Where have such incidents occurred?

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.

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

Relative Biological Effectiveness $(RBE)$ is associated with damage caused by ................

Initially,nuclear energy was considered as $...........$.