This study proposes a comprehensive Extended Reality (XR) framework for digitally preserving Nakhwa-nori, a traditional Korean pyrotechnic festival facing critical challenges including overcrowding-related safety risks, geographical accessibility barriers, and insufficient systematic documentation. Leveraging Unreal Engine 5's advanced capabilities—Nanite virtualized geometry, Lumen global illumination, and Niagara GPU-accelerated particle systems—we developed an immersive digital reconstruction system that authentically reproduces the festival's complex visual phenomena through dual-layer particle simulation architectures, physics-based environmental interactions, and spline-based structural modeling. Performance evaluation on consumer-grade hardware demonstrated stable frame rates (60-140 FPS) across quality settings, confirming technical feasibility for real-time cultural heritage experiences. This framework establishes scalable methodologies applicable to diverse intangible cultural assets while providing safe, accessible alternatives to physical attendance and creating authoritative digital records for cultural sovereignty protection. The research contributes a transformative paradigm for sustainable preservation of intangible cultural heritage through harmonious integration with advanced technological methodologies.