Power plants fund their own decommissioning [1]. And they also (in a way) already pay for disposal - a 1 mill per kWh fee on all energy generated payed to the federal govermnent in exchange for the feds taking responsibility for disposal [2]. This fee has been paid for decades - the industry has no problem supporting that level of disposal cost (and could even afford a higher fee if necessary). There has been an enormous amount of research into ways for dealing with the waste all kinds of disposal, treatments, recycling, etc. The only real blocker has been a lack of political/public will to make any decisions and move forward.
They are supposed to. But here in germany the energy company lobbists basically said - in response to a few new proposed fees levied on coal plants - that anything threatening their revenues would cut into future revenue needed for decommissioning fees. And that's despite being required to have funds set aside for decommissioning.
I suspect some creative accounting going on, moving expected future profits into those funds or whatever.
So if their business models fail - e.g. due to renewables - it might turn out that in practice there never was any money set aside for decommissioning.
There are even talks about splitting off coal and fission plants into some sort of "bad bank" companies.
So I would be very wary of any such promises of things being priced in.
Corporations have again and again proven to be very good at privatizing profits while externalizing costs.
Sellafield isn't an ordinary nuclear power station. It was part of the UK's nuclear weapons program and contained some of the UK's earliest (maybe the earliest) nuclear reactors.
It's not going to be representative of the decommissioning costs of modern generation II or generation III reactors.
Regardless of how much one is for or against nuclear power, i think we can all come together and agree strongly that building an air cooled nuclear reactor that uses a flammable substance as a moderator and blows exhaust out a chimney is a catastrophically bad idea.
And I don't imagine that kind of activity results in easy cleanup.
Also, AGR fuel needs to be condensed or reprocessed shortly after discharge. It's great in a gas reactor, not so much in a spent fuel pool. That means much of the UK's discharged fuel as been consolidated at Sellafield. But all that plutonium is a great fuel resource. Jealous of whoever gets to fuel their reactor with that goldmine.
Sellafield is a large site consisting of many facilities [1]. These include Magnox reactors [2] which were historically used to create weapons grade Plutonium and are much "messier" than typical commercial power reactors. The Sellafield site has been and is still home to a very large spent fuel reprocessing plant that handles spent fuel from numerous UK reactors. Reprocessing plants are an entirely different beast. And a lot of the activity at the Sellafield site is generally from older, messier technologies as well.
The cost will vary significantly from plant to plant - this range is likely due to plant-to-plant variation - not uncertainty in the cost for any single plant. Do you have a citation/reference for that?
Like I mentioned above - that cost is not uncertainty in single plant decommissioning cost. It is a range of much-lower uncertainty decommissioning costs for several different plant. The decommissioning cost is estimated by NRC and plant operators before the plant becomes operational and is periodically revisited. And decommissioning costs don't look nearly so big compared to the several billon $ for construction.
Since it costs several billion to build a plant, that decommissioning cost is somewhere around 10-20% of the construction cost, which doesn't seem too bad.
[1] http://www.nrc.gov/waste/decommissioning/finan-assur.html
[2] https://en.wikipedia.org/wiki/Nuclear_Waste_Policy_Act