Continuation from FY17... Many modern liquid rocket propulsion systems are utilizing hydrocarbon propellants (e.g. methane, RP-1). Testing of these new rocket systems will inherently involve the potential for large energy explosions. Current engineering methods do not address the probability of a detonation occurring and they are extremely conservative by attempting to equate the propellant vapor cloud explosion to a high-density explosive. The current project is leveraging CIF FY15 work done by NASA-SSC in which a validated tool for modeling hydrogen detonation and blast wave propagations in test facilities by following on to validate engineering level approaches for modeling the potential and associated blast environments for explosions of these hydrocarbon propellants.