Cryogenic Spill-Induced Structural Integrity of LNG Tanks and Containment Systems: A Comprehensive Review

Accidental cryogenic spills in liquefied natural gas (LNG) storage and transport systems can impose severe local cooling, transient thermal gradients, and failure-mode transitions that are not captured by temperature-only or strength-only assessments. This review synthesizes LNG spill physics, boiling heat transfer, cryogenic material response, containment typology, thermo-mechanical stress generation, and post-spill residual integrity assessment within a unified failure analysis framework. A structured narrative methodology was used to classify studies, reports, standards, and industry guidance by containment typology, cryogenic release and spill physics, material response, thermo-mechanical structural response, and failure analysis and prevention. The review shows that structural demand is governed by the release-conditioned thermal boundary state, including wetting, boiling regime evolution, heat flux history, exposure duration, affected area, and restraint, rather than by LNG temperature alone. It further shows that containment typology controls the vulnerable location and governing failure mode, from concrete cracking and membrane cold penetration to support region stress concentration and brittle fracture of transition-sensitive steels. Cryogenic integrity is therefore a coupled thermo-mechanical fracture problem in which material-specific mechanisms, including DBTT-controlled fracture, weld/HAZ vulnerability, nonlinear stainless steel plasticity, concrete damage localization, and leak tightness loss, must be linked to realistic spill conditions. Key gaps remain in boiling-aware structural modeling, large-scale validation, post-spill inspection criteria, and fitness-for-service procedures.