Reactor Casing is the structural block of the nuclear reactor room in the Ala Industrial mod for Minecraft 26.2 Java Edition: the walls, floor and ceiling of the shell that the Reactor Controller scans. Only seven block types count as shell — Reactor Casing, Reactor Glass (at most 30% of the shell), Reactor Lamp, the Reactor Airlock Door, the Reactor Inlet, the Reactor Outlet and the Reactor Controller itself — and every other block, plain stone and vanilla glass included, reads to the scanner as a hole. The interior may measure from 3×3×3 (a shell of 98 blocks) up to 12×12×12 (1016 blocks), and Reactor Casing is the only shell block free of placement rules: it fits any cell of any face, including the edges and corners where the door and the controller are not allowed.

One craft yields 8 Reactor Casing blocks from 6 Tempered Iron Plates, 2 Shielding Plates and 1 Machine Casing, so the mass of the wall is paid in cheap iron while the scarce palladium stays in the clever single pieces. The blast resistance of 30 is five times the 6 of the machine family, because the shell is what keeps a meltdown inside the room, and a pickaxe returns every block intact, so a small room can be taken apart and rebuilt larger with no loss. Reactor Casing neither conducts nor stores energy: a cable ends at the wall, and pipes cross it only through a Reactor Inlet. When the controller accepts the shell, the whole wall loses its seams and reads as one surface — the visible sign that the room is sealed. Ala Industrial runs on Fabric and NeoForge.