Fairly simple little proof of concept that I made, uses the lava dropped from plutonium explosions to provide constant heat (and, once it reforms, multiple explosions) to water, which boils and activates turbines. Will be adding a PSCN BRAY cooling system soon to recycle the water, and perhaps make improvements on the filter system.

EDIT: Cooling system added.

Thanks all, I've been pondering what to add to it and such. It is indeed simple, but to be honest it doesn't really need much more as far as I can see. The filtration system works, the heating system works, and it's fairly reliable. After the cooling engine, there's really not much more to be done.