Couldn't be simpler...
Add Warpradial FX either to your layout or the layer you wish to affect.
Set the values to.
The best way to activate and deactivate is simply query whether any explosions are on screen and enable and disable accordingly. As per the code below.
One of the tweaks I'll be making will be to alter the values to match the intensity of the explosion.
Check out the awesome effect below, with which I also used Scanlines to match the style of game... being that of a terminal.