Why is waste disposal of nuclear materials a serious problem? Underground storage sites cannot be sufficiently protected. Nuclear waste remains active for hundreds of years. No shipping companies want to transport nuclear waste. Rogue terrorists try to gain access to nuclear waste by-products.

Waste disposal of nuclear materials is a serious problem because nuclear waste remains active for hundreds of years.

Explanation:

The enriched radioactive isotopes of elements like Uranium and Plutonium are used to carry out nuclear reactions. Even after the reactions are over and the residues of these isotopes became incapable of undergoing any more fusion reactions, there is still a lot of radioactivity left in them. This radioactivity results in the 'emission of harmful radiations' which cannot be easily controlled. Hence, disposing off these nuclear materials is a tedious task.

The answer is: Nuclear waste remains active for hundreds of years.

We have had horribly problems with storing radioactive waste.