1.   A conventional bomb could scatter radioactive material over a large area.

2.   Experts used to dismiss the possibility that terrorists might try to deploy dirty bombs, which would scatter radioactive material over a large area.

3.   The explosion would then scatter radioactive material over a wide area.

4.   The devices use explosives to scatter radioactive material.

5.   They exposed Iraqi research on even more exotic weapons, such as bombs that would scatter radioactive material at the enemy and toxins aimed at destroying crops.