Storage of nuclear waste

[kerbiloid]

Deuterium is almost unlimited, and it produces a lot of parasite neutrons per Watt, which anyway should be absorbed by something (for example, by the oceanic water around the underwater powerlant).

Thus, the deuterium fusion is a mainstream way to power, and the wastes can be just put between the fusion zone and the oceanic water, to be splitted by the parasite neutrons for free.

As also the natural, non/low-enriched fissile ores can be used same way, and would be producing additional wastes, it makes sense to mix the natural thorium/uranium (for example, being extracted from the same oceanic water) with the existing wastes, and finally burn the latter by the fusion neutrons, and make the whole powerplant based on the oceanic water around.

[RCgothic]

20 hours ago, farmerben said:

I'm still a fan of accelerator driven reactors, which use a proton beam and spallation neutrons to incinerate nuclear waste.  These get rid of all the weapons grade material and longest lived waste.  You still have the cesium and strontium to contain for a few centuries.

People who are not fans of this approach mostly complain about the expense.  But the expense is worth it, if it eventually leads to cheaper and better proton beams.  Because proton beams have numerous potential applications including ones in spaceflight. 

One idea I have is that a deuterium beam could be way better than a simple proton beam as a spallation neutron generator.  To the best of my knowledge the research has not been done, and particle accelerators with deuterium have barely been tried.  It would be worth it to create one from a pure research perspective. 

The "longest lived" wastes are the transuranics that can either be bred into more fissile material and used as fuel or already are fissile and just need reprocessing. They're also the least dangerous constituent of used fuel and not worth going out of our way to annihilate.

 

On 7/26/2024 at 10:34 PM, darthgently said:

I certainly didn't mean bury it.  Just use a tapped out salt mine as a space to keep it secured from improper use

Given that there has never been an incident of anyone being harmed by dry-stored fuel and that nothing has ever been stolen from a dry store (casks weigh over a hundred tonnes and require specialist equipment to move or open), the salt mine is unnecessary. 

I think the only thing would be if a nuclear site goes inactive casks should be transferred to another nuclear site with active security arrangements, but that'd still be easier than a salt mine. I agree casks shouldn't just be left unmonitored.

[darthgently]

5 minutes ago, RCgothic said:

Given that there has never been an incident of anyone being harmed by dry-stored fuel and that nothing has ever been stolen from a dry store (casks weigh over a hundred tonnes and require specialist equipment to move or open), the salt mine is unnecessary. 

Five hundred years is a long time.  A lot could happen politically.   The salt mine is more to better protect it from misuse in periods of turmoil by making it more obscure.  Main concerns would be accidental water table contamination by the curious or terrorist dirty bomb construction.

[kerbiloid]

Based on the classics, 1ky looks relevant.

Spoiler

But leave an a-b-c book with pictures in the first room. They will first learn reading.

 

[DDE]

2 hours ago, darthgently said:

The salt mine is more to better protect it from misuse in periods of turmoil by making it more obscure.

Depends on what exactly you store there. Salt mines in north-eastern Ukraine containing mothballed WWII and WWI small arms were "opened up" rather promptly.

[magnemoe]

10 hours ago, DDE said:

Depends on what exactly you store there. Salt mines in north-eastern Ukraine containing mothballed WWII and WWI small arms were "opened up" rather promptly.

You stored weapons who is important in an war. And small arms will last an very long time if stored properly as they are rugged metal items. Know people who found guns hidden on barns during start of WW 2 who still worked after an good cleaning back in the 90's. 
If properly stored they are fine, wooden parts might need replacing. 

[farmerben]

On 7/30/2024 at 4:54 PM, Nuke said:

polywells might be better. you dont have grid erosion that contaminates the plasma and requires you to shut it down to change the grid or purge the contaminated deuterium. less consumables less down time. polywells might still be viable for breakeven at some point, its just the proponents opted for computer simulations rather than lab work to nail down the optimal design. best option for a spacecraft power supply if it works. but for now they make excellent neutron sources.

I heard that polywell disapperead into a venture capitalist blackhole, and hasn't released anything to the public in over 20 years.

 

[AckSed]

I do wonder if it might be viable to run a fusor just to generate helium. It'd take tons of power, but in return, you have a steady supply.

[darthgently]

29 minutes ago, AckSed said:

I do wonder if it might be viable to run a fusor just to generate helium. It'd take tons of power, but in return, you have a steady supply.

Short of fusion,  helium is a non-renewable on Earth (I think, corrections welcome).  And short of harvesting from stars or gas giants is probably too diffuse off planet to get together easily.  So a steady supply could eventually be worthwhile enough?

[Nuke]

11 hours ago, farmerben said:

I heard that polywell disapperead into a venture capitalist blackhole, and hasn't released anything to the public in over 20 years.

 

thats the problem with the little guys, they never seem to have the money to do the research they want. there was some mention on the talk-polywell.org forum that emc2 and others presented at tofe 2024 last month, though nothing seems to have been released to the public on that yet. will keep an eye on that.

bussard had wanted to move directly to a full scale demo before he died, when park took over he scaled back to some smaller tests and later to computer models, preferring a more thorough and conservative approach. rather than releasing whatever they had in a desperate attempt for capital (which seems like what fusion startups like to do). im not holding my breath. but with recent iter delays it seems like some venture capitalists might surge fund startups again hoping to get in before iter, though it might turn them off to fusion all together. iter is probibly going to do what it says on the tin, but in another decade or two, again and still require a demo to follow it up. so 50 years?

[darthgently]

16 minutes ago, Nuke said:

thats the problem with the little guys, they never seem to have the money to do the research they want. there was some mention on the talk-polywell.org forum that emc2 and others presented at tofe 2024 last month, though nothing seems to have been released to the public on that yet. will keep an eye on that.

bussard had wanted to move directly to a full scale demo before he died, when park took over he scaled back to some smaller tests and later to computer models, preferring a more thorough and conservative approach. rather than releasing whatever they had in a desperate attempt for capital (which seems like what fusion startups like to do). im not holding my breath. but with recent iter delays it seems like some venture capitalists might surge fund startups again hoping to get in before iter, though it might turn them off to fusion all together. iter is probibly going to do what it says on the tin, but in another decade or two, again and still require a demo to follow it up. so 50 years?

ITER operational and maintenance costs seem like they will be huge

[DDE]

7 hours ago, Nuke said:

rather than releasing whatever they had in a desperate attempt for capital (which seems like what fusion startups like to do)

Shower thought: the ideal form of a future energy breakthrough is probably not venture capitalism, but a Manhattan Project. It's strange why people think it would be any different from fission power, with its intense government involvement, strong focus on a relatively small number of technologies, and boatloads of taxpayer cash up front. All these dozens and hundreds of startups are just burning money and spreading the brainpower thin.

[darthgently]

3 hours ago, DDE said:

Shower thought: the ideal form of a future energy breakthrough is probably not venture capitalism, but a Manhattan Project. It's strange why people think it would be any different from fission power, with its intense government involvement, strong focus on a relatively small number of technologies, and boatloads of taxpayer cash up front. All these dozens and hundreds of startups are just burning money and spreading the brainpower thin.

On the other hand, multiple parallel approaches that have to make a case to investors (who have their own skin in the game, not boatloads of other people's skin collected in taxes) prior to getting funded is an incredible defense against centralized groupthink and isolates dead end approaches instead of enshrining them.  If one of these approaches shows promise, it will naturally grow.  Perhaps into a more centralized push once it has earned that focus. 

Spoiler

Further "out there", but worth mentioning, with the current decentralized model it is also easier to prevent fruitful state sponsored espionage and possible terrorist/extinctionist sabotage attempts as there are more targets and the dead ends naturally end up being false distractions to attempts such as this.  Not just for fusion research, but for any technological exploration.  This is how a free society succeeds where others often stumble a step behind and copying the innovative breadcrumbs that may fall from the table

 

[Nuke]

4 hours ago, DDE said:

Shower thought: the ideal form of a future energy breakthrough is probably not venture capitalism, but a Manhattan Project. It's strange why people think it would be any different from fission power, with its intense government involvement, strong focus on a relatively small number of technologies, and boatloads of taxpayer cash up front. All these dozens and hundreds of startups are just burning money and spreading the brainpower thin.

thats kind of what iter is and why it continues to be the best bet. but their target really isnt useful, especially in space applications. as a terrestrial power plant its gonna be a cash cow that will cost too damn much to operate.

[kerbiloid]

16 hours ago, darthgently said:

helium is a non-renewable on Earth (I think, corrections welcome). 

It's produced by the alpha-decay of U & Th, and is extracted from air, from natural gas, and from minerals like mona'zite and fergussonite.

6 hours ago, DDE said:

Shower thought: the ideal form of a future energy breakthrough is probably not venture capitalism, but a Manhattan Project. It's strange why people think it would be any different from fission power, with its intense government involvement

Imho, unlikely the venture capitalism will be able to survive the global automatisation, when 99% of population will be capitalless employee or unemployee (on welfare based on their social rating), and the other 1% will be a multikingdom of corporative family clans (needing money only as stylish casino tokens) and their privileged servants (on full state support).

Any venture would be strange for all three groups.

Thus, it will probably in any case be a government project.

Edited August 2 by kerbiloid

[Entropian]

On 8/1/2024 at 6:00 AM, farmerben said:

I heard that polywell disapperead into a venture capitalist blackhole, and hasn't released anything to the public in over 20 years.

They very much released information within the last 20 years - it's just that they found that the thing doesn't work at all and the idea is fundamentally flawed.

[farmerben]

13 minutes ago, Entropian said:

They very much released information within the last 20 years - it's just that they found that the thing doesn't work at all and the idea is fundamentally flawed.

links?