What happens when radiation leaks from nuclear reactors?
The radiation leaks into the environment causing radiative poisoning to the surround plants and animals, the very ground become radioactive perhaps for hundreds of thousands of years.
Radiation is absorbed by the elements in the surrounding environment. Iodine is changed into a radioactive isotope that is absorbed by living organisms. This radiation changes the atoms in the DNA causing mutations in the cells. These changes kill cells resulting in death due directly to cell death or possibility of cancers
The soil become radioactive so the grasses and plants that grow out of the soil become radioactive. Animals that eat the grass and plants then in turn become radioactive. The half life of some radioactive pollution are in the hundreds of thousands of years making the soil dangerous for vast periods of time.