Radiate doesn't have a module for it, but you can get creative with triggers and scripts and make your own.

Create a trigger, change the activation condition from "this" to "true", and place the following code in the "On Activation" box:
Then you can copy and paste the trigger anywhere to make a dust zone. The first argument is the ASL coordinates (automatically calculated with getPosASL(thisTrigger) on a trigger), the second is the type of radiation, third is dosage, fourth is radius, and an optional fifth is for height.