How much thermal energy, measured in joules per centimeter squared, would be required to:
melt (or ignite, if possible) commonly-used commercial airliner paint
melt (or ignite, if possible) commonly used aerospace composites
The reason I'm asking:
I'm working on writing a nuclear-jet powered aircraft in a sci-fi setting. It uses an indirect air cycle molten-salt-cooled reactor to heat air to provide thrust without using fuel (other than the occasional reactor overhaul/nuclear fuel change-out). Radiator panels are built into its skin. It's intended to be a subsonic, long-haul cargo vehicle - not some kind of fancy supersonic jet.
I'm writing a scene where it's flying away from a nuclear explosion (at do-not-exceed speed; its radiators are overheating already), but doesn't get far enough away to avoid its radiators exploding/leaking coolant and its paint melting due to the thermal effects. How powerful would those thermal effects need to be? I imagine that radiators filled with molten salt deforming would require a lot more heat per square centimeter than paint melting.
I asked for "common aerospace materials" rather than "cutting edge" because these things are intended to be mass-produced in a relatively futuristic setting.