Radioactive Wastes Radioactive wastes, must for the protection of mankind be stored or disposed in such a manner that isolation from the biosphere is assured until they have decayed to innocuous levels. If this is not done, the world could face severe physical problems to living species living on this planet. Some atoms can disintegrate spontaneously. As they do, they emit ionizing radiation. Atoms having this property are called radioactive. By far the greatest number of uses for radioactivity in Canada relate not to the fission, but to the decay of radioactive materials - radioisotopes. These are unstable atoms that emit energy for a period of time that varies with the