They were exposed to radioactive fallout during nuclear weapons tests.

他们在核武器试验过程中暴露于放射性核辐射。

The phenomenon is called radioactive fallout.

这一现象即称之为放射性尘降。

Producing a very great amount of long-lived radioactive fallout.

产生大量辐射微尘的产生大量的长期放射性下降物的。

On the other hand, the radioactive fallout at the plant keeps mounting.

另一方面，核电厂的放射性沉降物不断聚集。

Decay rates of the radioactive fallout are the same for any size nuclear device.

核辐射尘降物的衰减率不应核装置的大小而改变。