Uranium Block is the compact storage block added by the IndustrialCraft 2 mod, designed to bundle nine Uranium 238 items into a single inventory slot. Players craft one Uranium Block by filling all nine cells of a 3x3 crafting grid with Uranium 238, the same 9-to-1 compression pattern used for Iron Blocks, Gold Blocks, and Diamond Blocks in vanilla Minecraft. The recipe costs no extra tools or machines, so a stockpile of refined uranium becomes manageable long before a nuclear reactor is built. Uranium Block stacks to 64, which means a single column holds the equivalent of 576 Uranium 238 items and keeps a reactor hall's chests readable.

Uranium Block is a pure storage item with no radiation, no light output, and no special machine interaction, so the block is safe to keep in ordinary chests next to other gear. Breaking a placed Uranium Block requires only a wooden pickaxe or better, and the block returns cleanly with no loss. The reverse recipe is built in too: one Uranium Block unpacks back into nine Uranium 238 through the same crafting grid, which makes the block the standard way to bank surplus uranium between refueling cycles of an IC2 Nuclear Reactor. Builders also use the dense green texture as a compact accent block in industrial-themed bases, where Uranium Block reads as a heavy metal without the explosion risk of a live Nuke.