Inner cordoned area (safety perimeter) for a radiological emergency.| Situation with potentially dangerous source | Area |
|---|
| Initial determination — outside |
|---|
| Unshielded/damaged | 30m around |
| Major spill | 100m around |
| Fire, explosion or fumes | 300m radius |
| Suspected bomb (potential RDD)
| 400m radius or more |
| Initial determination — inside a building |
|---|
| Damage, loss of shielding or spill | Affected and adjacent areas, including floors above and below |
| Fires/other event spreading materials throughout the building | Entire building and appropriate outside distance |
| Expansion based on radiological monitoring |
|---|
| 100 µSv/h dose rate at 1m | Wherever these levels are measured |
