WoodScientist

Sometimes the simplest things hit the hardest.

That's amazing that a patient can be infected by a tumor located 5,000 km away from their body!

Why won't anyone love me?

Or here's another idea. If this is actually a real threat, how about we treat it like one? We can simply choose not to develop certain technologies; we've done it multiple times. We've had the tech for human cloning for decades, but we decided it was unethical and to simply not pursue the technology. We could do the same for AI beyond a certain level of complexity.

Hell, if this really is a threat to the human race, I would fully support just outlawing computers entirely if that's what it took. Fuck it, we'll just go back to pen and paper. It would be an extreme step, but if that's what it takes, so be it. We can go full Dune, "thou shall not make a machine in the likeness of the human mind."

Sometimes ships really are unsinkable. You can build a small boat out of materials that are themselves buoyant. If you make a boat of a foam material or some woods, you can submerge that boat at the bottom of a lake, release it, and it will pop right back up to the surface. It's hard to build an ocean liner this way, but there are truly unsinkable boats. There is a difference between safety by backups/safety mechanisms and intrinsic safety. Your car's engine cannot explode in a nuclear fireball. It's resistant to nuclear explosions not because of some elaborate series of safety mechanisms and backups, but simply because it lacks the capability to generate any kind of atomic reaction. Physics, not engineering, provides for the safety of unsinkable boats, your car's lack of nuclear explosiveness, and fusion-fission reactors.

You speculate that the beam may not be shut off fast enough. But there IS no "fast enough" in this context. This is not some system that has the capability of spiraling out of control. Imagine you had a combustion engine that was provided air by a blower motor. The blower motor can supply a certain m^3/min, and this is all the air the engine receives. The motor can only supply the engine so much air; it is fundamentally incapable of spiraling out of control.

There's no way for a fusion-fission reactor to explode in some runaway process. You design the neutron beam so that its absolute maximum power is still well below what would be required to turn the fission reactor into a pile of slag, like orders of magnitude below. You don't put some big honking fusion reactor in this system. You build your fusion portion so that it's only capable of providing enough neutrons for a gentle slow fission burn. There simply will never be enough neutrons in the system for the fission pile to experience runaway fission.

One advantage of these reactors is they're completely meltdown proof. You design the fission component to be sub-critical - the fission core can only maintain a reaction as long as the neutron flux from the fusion reactor is maintained. The neutron flux doesn't just enhance fission, it's a necessary component for the fission to keep going at all. And the fusion portion doesn't make net energy, it's just a glorified way of turning electricity into neutrons.

If anything goes wrong, you just flip a switch and shut down the fusion part of the reactor. Temp starts increasing too much? A sensor flips a switch and the fusion reactor shuts off automatically.

These are actually far, far safer than any pure fission plant. The nice thing about these fusion-fission plants is they can be designed to be completely and utterly meltdown proof. Regular fission plants have a self-sustaining fission reaction; the plant is designed to slow the reaction down and keep it under control. With a fusion-fission plant, you can design it the opposite way. You design the fission part to be sub-critical. You use a fission fuel that cannot maintain a self-sustaining fission reaction. You design it so that the fission part is only able to maintain a reaction if it has a giant neutron beam pointed at it. And that neutron flux is provided by the fusion part of the reactor.

If anything at all goes wrong in the plant, all you have to do is cut off power to the fusion reactor. The fusion component of the reactor cannot itself make net power; it consumes electricity to keep running. So you just it off, the neutron flux collapses, and the fission portion is unable to keep its reaction going.

I'm impressed. You have excellent language skills for a premie infant.