Chapter 15 · Nuclear and radiological emergency
15.1 Three different emergencies
"Nuclear emergency" can mean three very different things. Knowing which one it is changes what you do.
| Nuclear detonation | "Dirty bomb" (RDD) | Nuclear plant accident | |
|---|---|---|---|
| What it is | Explosion of a nuclear weapon: flash, heat, blast wave, initial radiation, and radioactive fallout. | Conventional explosive mixed with radioactive material. It is not a nuclear explosion. | A reactor failure that releases radioactive material (gases and particles) into the air. |
| Scale | Severe damage for miles; dangerous fallout up to tens of miles downwind. | Contamination normally limited to a few blocks or a few miles, according to the NRC. | Official planning covers 10 miles (16 km) for shelter/ evacuation and 50 miles (80 km) for food and water control. |
| Main danger | Blast wave, burns, and then the radioactive fallout. | The explosion itself. Most would release too little radiation to cause serious illness. | Inhaling or ingesting radioactive material, including radioactive iodine. |
| Advance warning | None, or minutes. | None. | Usually hours: there are sirens and alerts in the 10-mile zone. |
| What you do | Get inside, stay inside at least 24 hours, stay tuned. | Move away from the smoke and dust; get into a building; remove your outer clothing; follow instructions. | Follow the shelter or evacuation orders for your area. Potassium iodide only if instructed. |
| Does potassium iodide help? | It is not the priority: it does not block external radiation. | No: it protects only against radioactive iodine. | It may help, only if authorities say so. |
The "dirty bomb" in a nutshell
The Nuclear Regulatory Commission (NRC) calls it a "weapon of mass disruption": its goal is to contaminate and cause fear. A nuclear explosion is millions of times more powerful. If one happens near you:
- Move away from the site of the explosion and the smoke. Cover your nose and mouth with cloth as you leave.
- Get into a building. Close doors and windows.
- Decontaminate. Remove your outer clothing, put it in a sealed bag, and wash (see 15.7, "Decontamination on entry").
- Listen to the authorities. They will tell you whether to stay or leave the area and whether you need to be checked.
Protection rests on three principles: time (less time exposed), distance (farther from the source), and shielding (more mass between you and the radiation). They apply to all three emergencies.
