Whenever I see an article about storing nuclear waste for such longer periods of time, I can't help but think we will find a use for nuclear waste and end up digging it all back up way before 100,000 years.
It's hard to reason intuitively about long time scales, because nothing is fixed any more. Usually we imagine technology, demographics, culture, etc to be fixed with respect to our decision-making, because most of our decisions are very short-term (and because people are quite lazy thinkers and prefer to face problems with fewer variables). But longer-term decisions, everything is in flux.
It reminds me of that concept where if you want to travel to another star, the best time to leave is not 'as soon as possible'. It may actually be better to wait several decades or centuries to develop new propulsion technologies (possibly based on entirely new branches of science), launch later, and arrive earlier.
This is why vitrification was abandoned as a disposal mechanism. There are a number of interesting papers on how it would work well (example http://www.sciencedirect.com/science/article/pii/S0022311513...) however it makes it essentially impossible to reprocess fuel so disposed. Sad really.
And, while I try to hide my embarrassment---while Transatomic is BS, the concept of nuclear fuel cycles using waste is not, and many IV Generation designs are specifically working toward that. My main point was we likely won't need to wait millennia, or even centuries, for a lot of that waste to become useful.
Bah, my bad. I was just looking for a quick citation for nuclear fuel cycles, saw "MIT Tech Review" (usually a very good source), and grabbed it. Thanks for catching it.
The difficulty here is that radiation fries the brains of the robots, not that they aren't smart enough to work with the stuff. I was a bit shocked the robots people send to observe Fukushima die in minutes of exposure.
It's not something making smaller and faster transistors can solve.
The total volume of the oceans is about 1.35 billion cubic kilometers.
The total volume of the mantle is 909 billion cubic kilometers, roughly 1,000 times greater.
Moreover, the radioactive minerals which came out of the Earth's crust either originated within, or are otherwise found in, the Earth's mantle and core.
We're also talking about timecycles of hundreds of thousands of years, and, frankly, a mixing dynamic which is probably not well known.
I'm actually not much a fan of nuclear power (it's potentially useful, but highly problematic, and much more limited in capacity than is generally understood), but deep-mantle-injection would actually be, on the grand scheme of things, statistical noise so far as any radioactive risk is concerned.
We're also not aware of any biological activity occurring within the mantle. The problems with ocean pollution -- plastics, metals, fertilisers, etc. -- were that these are:
1. Generally unevenly distributed, with concentrations in specific areas.
2. Highly interactive with life forms -- biological concentration of heavy metals, forming algael blooms, etc.
3. For lighter detritus (especially plastics), confined to what's effectively a film at the surface of the oceans, rather than mixed throughout the full volume of the ocean.
Even for substances which do mix with seawater, such as CO2, the rate of mixing through the entire benthic column is a concern.
Where radioactive waste has entered seawater (numerous reactor cores, mostly from the nine nuclear-powered submarines which have sunk, waste disposal, and liquid discharge e.g., from Daichi-Fukushima), dilution with seawater tends to make this a very low-level threat at any distance from the immediate site.
(Despite this, I strongly discourage the practice.)
My point: in the list of risks to worry about, this isn't one I'd spend much time on. I've already spent more than it's worth.
We're making progress in scientific fields that are still in the growth stage of their evolution. There is little reason not to believe that these fields will not soon be any more moribund than say airplane technology has been for the last 40 years.
We still don't have the android maids that are past due, either. We've got a robot that does the vacuuming, and recently it was counted a major success to have a robot that could merely fold clothes (and only that). I don't know about you, but I think that free beamed energy is way more beneficial than a clothes-folding robot.
Or even if you count the awesome toys that Boston Dynamics puts out; they're still just that, toys. Incredible toys, but nowhere near taking over from humans.
We're nowhere near the AI that futurists of the past thought we'd have by now. Same goes for cancer cures (CRISPR).
This misses a few points. Key among them that projections of future technological development from 50 - 100 years ago have proved woefully inaccurate.
Drawing targets around what you shot at regardless of where you're aiming has a name: Texas Sharpshooting.
It's an exceptionally poor rebuttal or response to the observation that forecasts have failed. Moreso if in doing so the reasons for the deviation isn't specifically analysed.
After a period of a few hundred years it becomes a pretty ready to go repository of weapons grade plutonium. The problematic isotopes all have died away.
It reminds me of that concept where if you want to travel to another star, the best time to leave is not 'as soon as possible'. It may actually be better to wait several decades or centuries to develop new propulsion technologies (possibly based on entirely new branches of science), launch later, and arrive earlier.
Blast, I can't remember what that's called.