So I have a giant nuclear powered dragon. This beast is about 2 miles long with an equal wingspan and often spends the majority of its time asleep, passively absorbing nutrients from the air, water, earth, and sunlight around it.

Here are links to my giant dragon.

This is the dragon.

Here is more information, specifically ideas about the wings.

Now, aside from the myriad of other problems that come with a creature this size, I need a way to effectively cool it down. Obviously it spends a lot of time in the water, its various breath attacks cool it, as well as its huge wings. The thing is though, I don’t quite feel like that’s enough to cool it when it’s being active.

So, a little more info on the dragon. All dragons in the verse utilize metal in their anatomy quite heavily, and they are the only reliable source of the nearly indestructible super material known as dragon steel. Dragons have human level intelligence or higher and often have very long lifespans. These dragons sleep for a very long time, often years or even decades, during which time their functions slow to the point that their vital signs are undetectable. They have a “reactor gut” which stores radioactive material and allows the dragon to sustain and draw energy from fission and fusion reactions.

The dragon is currently cooled by:

  • Radiant cooling, especially from the wings
  • Active cooling by breathing out hot air and breathing in cooler air
  • Cooling by drinking and submerging itself in water
  • Cooling via vasodilation
  • Panting
  • Sweating

Now what I’m looking for is a very effective, and scientifically plausible, way of cooling this beast. I’m not looking for magic or hand waving. Even if a particular method of cooling couldn’t come about in a normal, organic creature, that’s fine, as long as it’s not completely breaking the laws of physics. Bonus points if said cooling system gives this dragon any particular abilities or qualities as a natural result of its operation.


1 Answer 1


Iron fusion.

Fusing light atoms is exothermic. Fusing iron and heavier atoms is endothermic.


The fusion reactions that make elements heavier than iron are endothermic — that is, they use up more energy than the reaction gives off. So “when you get an iron core,” Sneden says, “it sucks energy in and there’s a massive collapse.” This collapse generally produces a titanic explosion called a supernova.

Your dragon with its amazing biological nuclear reactor performs fusion of iron and other heavy elements (some of which it might have produced itself in its own reactions) and the endothermic fusion consumes heat energy. As well as makes even heavier elements.

Usually iron fusion is not useful in dealing with waste heat because of the star-type circumstances required to force iron to fuse. But usually we are not dealing with 2 mile long nuclear dragons.

  • $\begingroup$ I hadn’t even considered that! Fantastic! $\endgroup$
    – Nick
    Sep 17, 2021 at 22:44
  • 4
    $\begingroup$ Whenever mod drama or tiresome debates about the meaning of "story-based" threaten to finally push me away from this platform, questions and especially answers like this one keep me around. $\endgroup$
    – KeizerHarm
    Sep 17, 2021 at 22:49

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