Question

All nuclear wastes completely disappear after about 50 years

Answer 1

The most radioactive isotopes will decay very rapidly and be safe in much less than 50 years (e.g. iodine-131 with a halflife of about 8 days will be gone in less than 2 months), but less radioactive isotopes will decay so slowly they can be around for hundreds of thousand of years (e.g. plutonium-239 with a halflife of 24400 years will be gone in under 200000 years) to longer than the age of the universe (e.g. uranium-238). Slightly oversimplified, the most dangerous isotopes in nuclear waste tend on average to disappear first with less dangerous isotopes persisting for longer periods.

Answer 2

due to the process of decomposition. microorganism feed on dead and decaying matter and gets converted into humus. please mark my answer as brainliest answer.