Reinforced Stone

Reinforced stone is explosion resistant, and is a good choice for building a Creeper/TNT safe bunker, or for housing a nuclear reactor. It can be mined with a diamond pickaxe, or a Diamond Drill.

Reinforced Stone can withstand a nuclear explosion, if you build a wall at least 3 blocks thick. It can also be used to craft the Reinforced Door.

It is the second most resistant material afterbedrock with a blast resistance of 150. (In Vanilla Minecraft obsidian has a blast resistance of 6,000; however, obsidian was nerfed by Industrial Craft, lowering its blast resistance to 40)