Phase 260: The Shield Bricks — the 100mm water-filled borated-polyethylene wall lining. Two sizes (craft, habitat) plus shaped vehicle minis; every room loses 100mm per wall by decree; 2.5mm borated poly casing, molded cross-brace, indent-plug sealed underwater (zero free air — no slosh, no headspace stripe); pin-below/hole-above reverse-lego lock; 200x300 mains with 200x150 fillers in staggered bond (no straight seam — neutrons get a maze); corrugated water ceiling panels on a triangular point-down 316 rail; hooks never pierce the jacket; bridge and hangar ball walls comply. Chapter 5 of the radiation book; 1526's fifth leg.
Video not exactly as described in the instructions, but you get the general idea
