Meltdown

 is a perk in Fallout: New Vegas. Foes killed by your Energy Weapons emit a corona of harmful energy.

Effects
When a target has it's hit points reduced to 0 by an energy weapons critical hit or a sneak attack critical hit, this perk will create a small explosion around the target. A Meltdown explosion can cause critical hits and sneak attack criticals on nearby targets and propogate a chain reaction effect.