Distinctions of Radioactive Waste
Distinctions are drawn in terms of:
- the type and concentration of the radioactive elements within the waste;
- the level of radioactivity and the speed of decay (half-life) of the constituent elements;
- the aggregate state;
- the chemical and physical properties of the material;
- the quantity of heat emitted.
The quantity of heat emitted by waste is decisive in dictating how it is to be managed.
Radioactivity gradually decays
Radioactivity gradually decreases as a result of radioactive decay. The speed of the decrease depends on the half-life, which differs from element to element.
After the passing of every half-time period, the radioactivity decreases to half. After 10 half-lives have passed, the radioactivity of the material is less than 0.1% of the initial radioactivity. This also applies to radioactive waste.