The advantage with Fusion is that you can control what elements are exposed to the neutron flux and so control what sort of new elements or isotopes you get. For instance there's basically nothing in the air except for dust that will absorb a neutron and turn into something you have to worry about. And part of the design of a fusion reactor is to use lithium to absorb as many neutrons as possible to breed tritium to feed back into the reaction.

By contrast the byproducts of a fission reaction are set by the fuels used and include really nasty stuff like Strontium-90 and so on. But even fission plants are designed so that the radioactive byproducts are essentially all spent fuel or things contaminated by spent fuel. Neutron activation is a design consideration rather than a source of waste.

Of course the neutron flux will tend to enbrittle the metals used in it's construction which will have the effect of increasing maintenance costs.

Uranium mining is a nasty business. Deuterium concentration is, by comparison, just a bunch of water-filled centrifuges. Surly that would make a large difference all on its own, no?

  > The only up side is that the decay products have a shorter half life. So the waste will only be a problem for a century or so, instead of for millennia.

This sounds like a tremendous underestimation of the problem - handling waste.

We have people who live 'for a century or so' but we don't even have languages (now!) that have lasted a millenia.

Our current "decay product" of energy generation (carbon) is going to impact our world for a lot longer than a century. I'll take known-quantity, manageable century-long decay products over unknown-quantity, nearly unmanageable (large-scale carbon sequestration is hard) any day.

> we don't even have languages (now!) that have lasted a millenia.

Wut?

You might make the case that MSA and Classical Arabic is an exception, but MSA is not spoken natively AFAIK. Other than that, I cannot think of any examples where a language spoken by someone a thousand years ago would be intelligible now. Languages change in sound, structure and vocabulary over time naturally. That's how we got the Romance languages from Latin (which is no longer spoken). However, language standardization artificially slows down change, so current languages might last a lot longer. English hasn't changed that much since Shakespeare and the KJV. Maybe interesting to you: https://en.m.wikipedia.org/w/index.php?title=Conservative_(l...

What about Hebrew?

Yes, for written form you could make that argument, though there are some differences between the two. Also, it didn't really "last" in the normal sense, since it was revived in modern times.

Also, Tibetan maintains the same spellings from 1200 years ago, but that really just means that it's very, very difficult to spell, since the pronunciation no longer matches spelling well.

These make interesting exceptions to the general rule, so I think the original point is still very valid. I'm curious about old vs. modern Syrian, if anyone knows about that.

Okay, point taken - we certainly do have some languages still in use that that have lasted more than a millennia.

I'd posit that storage is not a solved problem, and a big part of that is a lack of confidence that we can reliably communicate with the people who will have to deal with this waste in the distant future.

There's also the inherent disdain involved in passing on massive costs and risks to future generations to solve a comparatively short-term problem of ours.

Not really, fusion needs to keep the reaction in a near vacuum where fission uses a multi loop system which creates a lot more surface area and waste. Further the blanket needs to be made from lithium to make tritium in a DT fusion setup capturing those fast neutrons without creating long term waste.

Most importantly they are vastly safer and thus need far less security and far less insurance. Remember a huge benefit for PV solar and wind is they don't need guards.

PS: Another consideration is the half life is short enough that over 20 years things become a lot less radioactive. Fission has some half lives just long enough to be a real pain.

Don't you get a lot more energy for a given amount of radiation?