It is mostly because of military influences (proliferation risk) and environmental activism that these solutions have never been fully developed and deployed.
There are actual risks with handling really dirty waste and turn it into really dirty fuel - you can't just hand-wave away that as "environmental activism."
It's much more risky than just leaving the waste in a pond cooling for 20 years while hoping that you will be retired before someone actually have to get rid of it.
Of course there are risks -- but are those risks really of a different order than having to build nuclear storage containers that will hold for thousands of years?
I'd say that activism has left us with the most undesirable outcome: we still have ancient reactor designs producing unmanageable waste, and every solution to actually reduce that waste has become politically unfeasible. All that we've done is create massive amounts of technical debt that will burden generations to come.
Are they wrong though? proliferation risk seems to me an important point. Also are risk of theft, attacks on facilities and transportation, leakage due to natural disasters, and of course: bad politicians doing "unavoidable" cuts. Moreover, even with FBRs you get Pu-contaminated MSO (http://e360.yale.edu/features/are_fast-breeder_reactors_a_nu...).
Once you take all these issues into consideration you just need to extrapolate and see how nuclear accidents will happen once in a while.
It's a non-problem, compared to various other chemicals we deal with in industry. Nuclear waste is relatively easy to store and there isn't a lot of it. Yes - it's nasty, toxic stuff, but we know how to handle it.
Having to store some of it isolated for 10000 years is a concern, yes, especially if you look at the average lifespan of human civilizations. But we already have ways to reuse the waste (fast breeder reactors), and we could likely figure out many more - but reluctance to fund nuclear research and applications, driven partly by the fear of "the waste", is not helping here.
The main benefit - IMO - is that it's relatively compact, lightweight, and solid compared to CO2. If there was a cheap and simple way to condense CO2 into a solid, we could stuff that into the ground instead. But CO2 would have to be stored indefinitely - we will probably see the catastrophic effects of what happens when stored CO2 is released in the atmosphere (permafrost, ice and ocean sediments are releasing their stored CO2 atm). Actually, fossil fuels can be considered to be stored, solid or liquid CO2 already, accumulated over tens or hundreds of millions of years.
On that scale, putting something away for 10K years seems relatively trivial and safe compared to CO2.
