3.8.1.8
Nuclear waste is classified by activity level and stored accordingly
Nuclear Energy & Binding Energy — AQA A-Level Physics
Low-level waste
- Clothing, gloves, tools that are lightly contaminated.
- Radioactive for a few years.
- Encased in concrete, stored a few metres underground until safe for regular disposal.
Intermediate-level waste
- Waste from decommissioning reactors — everything between daily items and fuel rods.
- Longer half-lifeThe time taken for half the number of radioactive nuclei in a sample to decay, or for the activityThe number of nuclear decays per unit time. Measured in becquerels (Bq), where 1 Bq = 1 decay per second. to halve. than low-level waste.
- Encased in cement in steel drums, stored securely underground.
High-level waste
- Spent fuel rods and fission products. Extremely hot and highly radioactive for thousands of years.
- First placed in cooling ponds near the reactor for several years.
- Plutonium and uranium are harvested for reuse.
- Remaining waste is vitrified (mixed with molten glass and solidified), encased in steel/lead/concrete containers.
- Stored very deep underground to prevent release from natural disasters.