> The idea is to transmute this nuclear waste into new forms of atoms which don’t have the problem of radioactivity. What you have to do is to change the makeup of the nucleus.
Ok, but what exactly is it transmuting the atom to?
Here's the list of the 7 long-lived fission products [1]. The nastiest appears to be Caesium-135 [2]. If you zap this with a proton it becomes Barium-136, which is a stable element (the half-life is so long that it cannot be estimated; probably it is in the trillions of years).
I also wonder about that. If it transmutes into the natural decay products, energy must come out, and, depending on the size of that laser/proton gun, we could (although I think that’s highly unlikely) even be talking about a way to make small nuclear bombs.
Also, will the end result still be energy positive? Even if the transmutation doesn’t add energy to the nucleus, that can be problematic, as that laser will need to be powered.
And of course, there’s the question of ‘aim’: can we really target individual atoms well enough to ‘hit’ them exactly once? (this might be fairly easy if the process requires specific energies that the radioactive atoms, once ‘hit’ no longer are sensitive to)
It depends on the decay mode. Through beta decay they usually go up (eg. Cs135 › Ba135) one spot in the periodic table (straight line in the diagram). Through alpha decay they go down as shown in the diagram. What the diagram represents is natural decay of Uranium which isn't "waste". The long lived fission products in the GP link are more or less of an issue.
I think the best option would be to accelerate the decay. That should be relatively easy (i.e. has a net energy output) and massively reduces the radioactivity.
Yes, but short-term high-radioactivity material is easy to do with, as is the super-long term low radioactivity material. The problem is the stuff in the middle which has a long enough half life that it's hard to store safely for that long but enough radioactivity to be dangerous. So if you can turn that stuff into either of the previous two catagories it's a win.
Radioactive materials are dangerous because their subatomic makeup is unstable, meaning they emit dangerous particles as the atom degrades from the inside. So it would seem that, in order to fix that, you'd have to re-populate the innards of the atom with enough protons to make it stable again.
It's worth noting that transmutation is definitely possible. The alchemists of old would be thrilled to know that we can, in fact, make gold from base metals (in a nuclear reactor). The problem with that is that the cost of doing so is worth more than the gold could be sold for.
Ok, but what exactly is it transmuting the atom to?