radioactivity

The place was still hot, but it was thermal heat, not radioactivity.

The amounts and kinds of radioactivity released to the environment.

Remove them and measure the radioactivity produced from the sample.

The owlies had learned what radioactivity meant, back when they fought the humans.

They were unable to venture into his old one because of the radioactivity and micro-organisms.

They had donkeys, and pigs, and chickens, and other animals that they exposed to radioactivity.

Those films would have to be well-buried, to shield them from radioactivity.

Vacuum-packed in moisture-proof containers, and free from radioactivity.

"Radioactivity hasn't dropped since morning; I'd think so, too," Melroy said.

It could only have been the result of radioactivity in a large mass.