Most processes do not scale linearly and offer new engineering challenges at certain cusps. A good example could be the nanopowder core of the reactor. If heat is generated uniformly within the core and extracted only at the surface of the core the process can mimic the heat enginee of corpulent people.
As a human's weight increases, heat is removed from the body by the square of the radius (assuming a spherical human); but, is generated by the cube of the radius. Ask Jabba. :-) T
