This is ignoring that nuclear will invariably have a worse mass fraction and thrust to weight ratio making the comparison even worse.
It all annoys me, we need better materials.
Discussion
That may be true for nuclear rockets, but what about nuclear pulse propulsion?
I suppose many of the proposals I've seen for really effective nuclear rockets use some sort of magnetic containment to skirt the materials limitations. That's probably a shaky thing to deal with, if nuclear fusion attempts are any indication.
Yes. Nuclear pulse is better. Magnetic confinement might work for fusion but it would be tricky for fission. You'd have to let your nuclear fuel melt or even vaporize to get hot enough. That'd be a bear to regulate without control rods.
You can do nuclear electric with ion engines, but those are such low thrust that they'd still be slower than chemical in the inner solar system. Could be very attractive for missions to the outer planets though.
Nuclear pulse would be the way to bootstrap ourselves into the solar system, IMO. Powerful and efficient. Long-term you want fusion, but you can figure that out later.
Electrostatic dusty plasma, muh man. Proven in lab, never flown.