- nuclear waste, after a period of the order of ~10e2/3 years is only dangerous if ingested. So it's as dangerous as any other poisonous substance after that point. There is no need for radiation shielding from that point.
- nuclear waste is very dense and so physical surface storage is cheap, and a solved problem (see: dry storage casks). We can fix leaks if/when they happen. Waste is concentrated
- current nuclear power stations (light water reactors) burn about 3% of their fuel leaving 97% unused in waste. There are nuclear power solutions which would burn most of the fuel (leaving very little for waste). So if we developed these technologies (see molton salt reactors being one of them) then nuclear waste would no longer be called "waste" as it would suddently become an extremely valuable feedstock for use in reactors.
- related to the prior point: why is it that we think we will not find a use for this very valuable and rare reasource in the future. We should think of nuclear "waste" storage as "rare element storage" which will be very useful under some states of the world. We just don't know how yet.
- as with any technology it should also be compared to the alternative when considering it's fitness: waste from the alternatives is far worse
100-1000 years order of magnitude. I can't remember exactly, but it's well within our ability to engineer and manage, rather than the signs that try to answer the "how do we communicate danger to later species" types of timelines
In 2015-2016 I did some mechanical engineering work at BWXT, designing nuclear waste containers for the Bruce Power CANDU reactor refurbishment program.
I learned that the spent fuel storage is pretty trivial for a few reasons:
1. The amount of fuel waste produced by a reactor is volumetrically tiny. So it's not too expensive to just have a relatively small guarded yard of sealed storage casks next to the reactor, where the fuel can sit and decay until safe for offsite disposal (typically around 60 years).
2. Safe waste storage containers are relatively easy to make. Most containers only need to be a thick stainless steel inner liner and a stainless steel outer liner filled with a special mixture of concrete. The nuclear waste is dropped in, the lid is bolted shut, then the container can be safely left in a guarded open yard for >100 years. They are safe by virtue of just having ridiculously thick welded stainless steel walls. We designed them to fall off a train going over a bridge, fall 300ft onto solid rock, and not break.
3. Reactor technology keeps getting better at extracting more energy from fuel. So what was "waste" in a past decade, can be put back into a reactor that is better at pulling energy out of the fuel. For this reason, there hasn't actually been much actual "fuel waste" in the history of the nuclear industry. It's all just being stored for future use by better reactors.
Why would you decommission them after all that investment instead of re-fitting? What would the ecological consequences would be if you demolished the Hoover Dam? Some things just have to be built to last as long as they physically can.
For the parts of the plant that cannot be put into landfill then storage like any other waste. Given how long they last, and how much energy they output, the waste is still very low per unit energy. Try this:
Basically, nuclear waste from power generation is a much smaller problem than people assume it to be, the solutions for managing it are already in place, and there have been few/if any accidents that have ever caused contamination from waste disposal.
Also I'm not an industry shill, but orphan sources from industrial/medical radiography have killed and injured more people than nuclear plants and their waste. Yet there's hardly the amount of opposition to those systems that you see for nuclear power, despite nuclear power having a far more significant impact on the healthiness and stability of global populations if we stopped banning it.
They could do what the fossil fuel industry does and just disperse it into the atmosphere until it disappears behind background radiation.
Realistically deep geologic storage is absolutely fine, and even if it's not happening now, all of the waste can be safely stored above ground for hundreds of years.
After the Fukushima disaster, radioactivity was detected in the seawater off the west cost of America. This, of course, threw people into a panic, despite being detectable only with very sensitive equipment and was not a danger to anyone or anything.
To be more specific, you would not have been able to detect Fukushima waste based on radioactivity, as the radioactivity would not have been detectable above the normal background radiation.
They could only identify the waste by it's distinct radiological profile. Otherwise it was just another source amongst millions of ionizing radiation that bathes us every day.
- nuclear waste, after a period of the order of ~10e2/3 years is only dangerous if ingested. So it's as dangerous as any other poisonous substance after that point. There is no need for radiation shielding from that point.
- nuclear waste is very dense and so physical surface storage is cheap, and a solved problem (see: dry storage casks). We can fix leaks if/when they happen. Waste is concentrated
- current nuclear power stations (light water reactors) burn about 3% of their fuel leaving 97% unused in waste. There are nuclear power solutions which would burn most of the fuel (leaving very little for waste). So if we developed these technologies (see molton salt reactors being one of them) then nuclear waste would no longer be called "waste" as it would suddently become an extremely valuable feedstock for use in reactors.
- related to the prior point: why is it that we think we will not find a use for this very valuable and rare reasource in the future. We should think of nuclear "waste" storage as "rare element storage" which will be very useful under some states of the world. We just don't know how yet.
- as with any technology it should also be compared to the alternative when considering it's fitness: waste from the alternatives is far worse