HISI, High-tech Submarine Interior, hisi_pdooro, open armored submarine bulkhead door with thick reinforced metal and circular locking wheel swung aside, revealing a reactor chamber beyond, cylindrical glass-walled reactor vessel filled with bright blue Cherenkov radiation glow, transparent liquid core with internal moderator structures and vertical luminous rods, dense surrounding pipes, cables and reactor support systems, heavy industrial framing and sealed containment housing, radiation hazard marking on lower unit, strong contrast between warm red corridor surfaces and intense blue reactor light, reflections and light spill across metallic floor panels, confined high-tech nuclear engineering environment, high detail textures, cinematic depth