For SL and HL, managing nuclear waste is challenging because some waste remains dangerously radioactive for thousands of years. It therefore requires reliable cooling, shielding, transport, monitoring, and isolation from people and ecosystems across many generations.
In nuclear fission, unstable, often neutron-rich nuclei are produced. These undergo radioactive decay, emitting ionizing radiation as they transform into more stable nuclei. Activity decreases with time, but isotopes with long half-lives decay slowly and remain hazardous. Spent fuel also produces decay heat, so it requires cooling after removal from a reactor.
| Challenge | Why it matters | Management response |
|---|---|---|
| Ionizing radiation | Can damage tissue and raise cancer risk | Shielding, remote handling, restricted access |
| Long half-lives | Hazard persists for millennia | Monitored storage and deep geological disposal |
| Decay heat | Spent fuel can overheat | Cooling pools, then dry-cask storage |
| Leakage | Soil or groundwater may be contaminated | Immobilization, sealed containers, multiple barriers |
| Transport | Accidents or attacks could cause exposure | Shielded containers and strict regulation |
| Security | Material could be stolen or misused | Safeguards and controlled facilities |
| Cost and responsibility | Oversight must continue across generations | Long-term funding and government regulation |
Waste may be immobilized by vitrification, which incorporates radioactive material into glass, then sealed in corrosion-resistant containers. Deep geological disposal places high-level waste in stable rock formations. Multiple barriers are used because no single container can be assumed to remain intact indefinitely.
A common misconception is that reprocessing eliminates nuclear waste. It can recover usable uranium and plutonium and reduce some waste volumes, but radioactive products still require secure disposal.
Exam technique: For an Explain question in E.4 Fission, link each property to a consequence and response: a long half-life creates a long-term hazard, so geological isolation is required. Do not merely list storage methods without explaining their purpose.
