BANG!
A Nuka Grenade is a craftable grenade that does much more damage than a standard Frag Grenade. When thrown, the grenade produces a high powered explosion seconded only to the Fatman's Mini Nuke explosion, and Bottlecap Mine (with perks). The Nuka Grenades are like Molotov Cocktails in that when they erupt into a blue fireball, and the fires (as well as a radioactive fallout field) linger for a few seconds afterwards.
The grenade is found in higher levels on corpses and various lootable objects. It can also be created using the proper Schematic.
Multiple schematics will increase the number of Nuka Grenades made from a single set of ingredients. Two schematics will make two Nuka Grenades from the same amount of materials, and three schematics will make three grenades. The damage of the Nuka Grenade does not change.