Shielding: To prevent irradiation, workers use dense materials like lead to absorb radiation before it reaches the body. Lead-lined boxes are used for storage, and lead aprons are common in medical environments.
Distance and Time: The intensity of radiation decreases with distance; therefore, using tongs to handle sources ensures a safer gap. Minimising the exposure time further reduces the total radiation dose received.
Monitoring Exposure: Personnel wear dosemeters (radiation badges) that contain photographic film or specialized crystals. These devices measure the cumulative amount of radiation a person has been exposed to, ensuring they do not exceed safe legal limits.
Storage by Emission Type: Waste is categorized by its activity and penetration. Alpha waste can be kept in simple metal canisters, while high-level Gamma waste requires thick concrete silos and lead lining to contain the rays.
Long-Term Disposal: High-level radioactive waste remains dangerous for thousands of years. It is typically buried deep underground in geologically stable locations to prevent release through earthquakes or groundwater seepage.
Container Integrity: Disposal containers must be rust-proof and corrosion-resistant to ensure the radioactive material remains contained even as the external environment changes over centuries.
| Feature | Alpha Hazards | Gamma Hazards |
|---|---|---|
| Most Dangerous | Inside the body (Ingested/Inhaled) | Outside the body (Irradiation) |
| Primary Reason | Extremely high ionising power | Extremely high penetrating power |
| Skin Penetration | Blocked by skin/paper | Passes easily through the body |
| Protection | Masks/Gloves (prevent intake) | Lead shielding/Distance |
Contextual Danger: Always identify whether the radioactive source is inside or outside the body before stating which radiation type is most dangerous. Forgetting this distinction is a common reason for lost marks.
Precise Terminology: Use the term 'ionising' when describing why radiation causes cancer (it damages DNA), and 'penetrating' when explaining how it reaches the cells.
Safety Measures: When asked to list safety precautions, specify why the precaution is used (e.g., 'use tongs to increase distance and reduce intensity').
Half-Life Awareness: Remember that waste with a long half-life remains a contamination risk for much longer, necessitating more secure, long-term geological storage compared to short-lived isotopes.
