Here a very basicaly tutorial that explain you how to make a 3D Radioactive image....

Go to object and create a cylinder.

Now apply this parameters (you can use aslo other parameters):

Here a preview of what we have do..

Now clone it two times and rotate it by 120°.

Now crate an other cylinder in the center with this parameters and clone it two times:

And here the preview :

Now select one of the three Cylinders, go to Compound and apply Boolean Compund Object

Now select Pick Operand B (parameters of boolean compund object) and select one of the three cylinder that we have made in the center:

Now repeat Step 5 and Step 6 for the other two sliced cylinders, after then you will see this:

Now make a cylinder in the middle with this parameters:

Now change material and press F9 to render it. Here you have 2 final render images: