Prismatic (or cylindrical) TRISO also makes sense. There are lots of potential problems using pebble beds (circulation, grinding), whereas doing regular refuelling cycles avoids them, in exchange for down-time to refuel.
The positive schpiels say it gets higher utilisaton ("burn") of the fuel inside the micropellets, so it may be HEU, but there's more taken out so less made overall.
I'm unsure where the H in HEU comes from, probably nasty sources, and probably nasty radiochemistry.
The Rolls Royce modular reactor update page [1] leaves me scratching my head as to where they are, it seems they've passed some really hard UK regulation though, maybe the official source is not the best:
From the article:
> We said criticality in 2026, electricity production in 2027, and power to the warfighter in 2028.
Are there any other examples of land-based militaries using nuclear power? Seems kind of like since they can't talk about the energy transition or w/e this has to be a military thing instead.
That's originally what the SL-1 reactor was meant for. It was also developed at Idaho Falls.
Instead of parking diesel generators up at Arctic radar stations (and other remote locations), we'd use a nuclear reactor, which is a logical choice.
The problems were:
1) one control rod could send the entire reactor prompt critical
2) rods could get stuck, requiring that they be "exercised" very carefully as to prevent them from making #1 happen
3) this maintenance was being done by a man in his early 20s who had been sleep deprived and received a phone call before his shift from his wife asking for a divorce
The result was the only immediately-fatal reactor accident in American history.
Glad to see that we're getting over this and moving forward with the concept. Only took us 60+ years...
"Stalin is proud to support the rebirth of Soviet Russia’s nuclear industry and ensuring soviets have access to affordable, reliable and secure energy for generations to come". Always mention the fearless leader.
To add a bit of context there were 11 companies participating in program and only 2 achieved critiality, and the deadline included in "DOE Reactor Pilot Program" was "July 4, 2026", and Aalo Atomics is the only one that might also make it in time.
Sigh, everything is being done for political purposes, now Dear Leader Donny can proclaim on the quartermillenial celebrations that "we achieved a nuclear milestone!". And maybe add that this is possible because of his nuclear physics genius abilities.
I wouldn't even be surprised if the achievements are like "Full-Self Driving", announced hastily with boasts and then slowly revealed to be full of Elon.
China does: all of the above, where it makes sense.
Renewables and batteries to keep your AC, workplace EV charger, stove, pool heater and (since recently) green ammonia producer going, nuclear to prevent e.g. aluminium smelters from seizing up.
Also the cheapest way to make renewables work 24/7 is to build HVDC lines - they cost as much as a highway per unit length and even undersea cables would deploy for less and faster than equivalent nuclear.
The total length of HVDC lines just in China is currently more than 40k km, so they've literally deployed enough of them to wrap around the globe.
China is also still building coal and has passed Europe and will (if they don’t change course) soon pass the US and Canada and the other big ones on a per capita emitter basis. They already passed everyone as top emitter in an absolute sense.
Not saying they’re not also building renewables and nuclear, but it seems like the policy is more “build anything and everything to satisfy demand” than a focused effort.
BTW: if you look at US emissions, the data center bubble hasn’t had much if any effect. They are still trending down. There’s reasons to dislike that industry but I’m sick of the mindless echo chamber doom on that issue. They’re not that significant in the grand scheme of things.
If your location already has a well-run nuclear energy sector (Finland, Sweden, South Korea): invest in nuclear energy.
If you don't: stick to renewables.
And it also depends on what you mean by "we". As a Dane, I don't think us Danish taxpayers should invest in nuclear energy, but I'm perfectly happy that private Danish investors invest in Seaborg/Saltfoss and Copenhagen Atomics.
Nuclear is not on a trajectory to do more than supply a minor amount of world energy. A (say) 10% nuclear, 90% renewable world is not an easier challenge than a 100% renewable world -- the intermittency/seasonality issues aren't eased by having 10% nuclear running as baseload, and keeping it as backup makes its cost per kWh explode.
Nuclear really has to go big (supply most of the world's energy) or go home. But supplying most of the world's energy means burner reactors are inadequate -- there isn't enough cheap uranium. Burner microreactors have even worse neutron economy, so this argument applies even more so to them.
It's more of an engineering call than something that can be purely determined from inductive reasoning. I think most engineers working in the space would say "both" are needed, but partisans exist on both sides.
That's a political and economic question, not a scientific one. Science can provide input information, but the decision involves weighing all sorts of facts and considerations outside the scope of science.
Nuclear partisans like to call renewables ideological, but I think this is another example of "the accusation is a confession".
The empirical evidence has nuclear being uncompetitively expensive. The current focus on variant reactor designs appears to be something of a Hail Mary attempt to get around this sad state of affairs.
You sometimes see them making an argument about energy density, which goes back to Vaclav Smil. But Smil used this argument to massively mispredict how solar would be go in the market. We don't hear him much anymore.
Nuclear advocates increasingly resort to conspiracy theoretic reasoning to explain away the failure of their technology to compete. This should be a red flag.
> The empirical evidence has nuclear being uncompetitively expensive.
France nuclearized 75% of its grid in the 1980s while the solar folks were faffing around. It's not a cost issue, it's that anti-nuclear folks have choked out the industry.
We need to take the boot off the neck of nuclear. Wind and solar aren't an avenue to moving up the tech tree of civilization, which will involve using vastly more power.
Fusion's main accomplishment will likely be to make fission look cheap in comparison, due to fundamental issues of power density in the nuclear island. Why make a huge complex low power density radioactive thing when you can make a much smaller simpler high power density radioactive thing?
We should be investing in all non carbon emitting sources and we should have been doing it since the 1970s when we figured out pretty conclusively that this would be a problem.
Instead we had right wing fossil fuel shills on one shoulder and unscientific woo woo greens on the other, the net effect being that we kept burning more carbon. We still have them, Trump with “beautiful coal” and greens now opposing even solar power and batteries, but climate change is no longer possible to ignore. Some still manage it but those people are nuts.
If we hadn’t stopped improving nuclear we’d probably have emitted half the CO2 we have. It would have become cheaper and safer and more scalable and then when China industrialized they would have copied that instead of burning so much coal.
France with its nearly zero carbon grid is the existence proof.
It wasn’t until the 2010s that solar and wind became grid scale in a big enough way to matter. That was too slow.
Whether someone is at least open to nuclear power is my litmus test for whether they take climate change seriously.
I do. If we hit 600, 800, 1000 ppm CO2, which is possible if the world keeps developing on the back of fossil fuels, we are entering existential risk territory. Earth has had those CO2 levels before, and higher, but our species was not alive then.
We already passed the FAFO threshold for ppm CO2 and now we will FO. But that’s not X-risk yet. I’m talking about the next threshold, which may start around 600 but really kicks in near 1000. This is where you actually start asphyxiating. You get lowered IQ and impaired judgement to a small degree, but across the globe at a time when we really don’t need it.
Is anyone working in the US on a waste solution that isn’t a big hole with a straight out of cyberpunk sci-fi warning plaque?
The French reprocess and recycle fissile material but that’s kind of a gnarly industrial process. Still they do it and it works.
The long term solution is to create a second kind of reactor that has a higher burn fraction which means a more fuel efficient fast reactor. Those would be, ideally, the big base load plants if we did this rationally.
I don't see the issue with dry cask storage medium term, and deep geological storage long term. Spent fuel isn't really that dangerous once it's been cooled down and for a couple decades before putting it in the ground, to the point that there are far more dangerous natural things you can dig up.
What concerns me is that 250 years of fossil fuel energy continues to store its waste products in my lungs and the water I drink. That's the issue we need to solve with urgency.
Europe has about 60,000 tons of nuclear waste storage[1], so lets say the global nuclear waste quantity is 2-3x or 120,000 to 180,000 tons. That sounds like a lot, however it's less than 2 weeks of coal deliveries to a coal plant (at 1 train of 115 cars each with 116 tons of coal = 13,340 tons delivered per day[2]). To take another approach, the average landfill size is 600 acres[3].
The "eh, just bury it" approach is really not a bad one. Its not even that much stuff to bury
I thought something like 30 tons per Gwatt capacity per year was the ballpark for high level waste without reprocessing? How are you arriving at a 120,000 ton estimate?
Fast neutron reactors can also "burn" waste from other reactors, the "ashes" are radioactive for only 300 years, there is no need for special storage after that. Untreated waste has to be kept in storage for around 100K years before it reaches safe levels of radioactivity.
Other than marketing propaganda, there isn't much real information about Mark-0. I'm assuming it's a sodium cooled, slow and hot pebble bed reactor. Hot pebble beds are well known but one with sodium cooling appears to be a first.
Why slow sodium? You get all the risks associated with sodium with none of the benefits of fast neutrons. There are operational, electricity producing, fast sodium reactors which do make some sense. I can't say the same for Mark-0.
IMO, the long term solution will be to simply launch the waste into space. With low enough launch costs the extra mass needed to armor the waste against accidents becomes tolerable.
A much better, safer, and cheaper idea is dropping suitably packaged waste on the subducting side of the Mid Pacific Subduction Zone. It’d be inert long before seeing daylight again…
The only downside is the “waste” is quite valuable. MSRs can also use it, and their waste is only dangerous for ~300 years.
Probably not worthwhile. If you just leave it in orbit you're going to have to track it and worry about debris/micrometeoroid strikes. The ideal would be to stick it in some permanently shadowed crater on the Moon, it'd be a stable environment without wild temperature swings and much lower risk of somehow ending up where people are. But that's a long way to go and a lot more risk to take for now.
Unless you live in Sci Fi future where space travel is magically free, this is a pretty bad deal since sending a pound of spent nuclear fuel out of earth orbit takes 50+ pounds of fuel. Sending all the spent nuclear waste into space would be something like 10 million tons of fuel.
> "The Trump administration is proud to support the rebirth of America’s nuclear industry and ensuring Americans have access to affordable, reliable and secure energy for generations to come."
> "The demonstration and the licensing pathway it establishes represent a key step toward deploying electricity-producing microreactors for U.S. military installations by September 30, 2028."
So which is it? Power to the people or power to the military? This microreactor concept doesn't seem very well suited for commercial use.
Why would microreactor concepts not be suitable for commercial use? History is overwhelmed with examples of large, rare and expensive tech being produced in small cheap packages and becoming massive commercial successes that make the old way look primitive.
Because large scale production is generally more scalable and efficient. And you probably don't want dozens of "microreactors" scattered across cities.
Can you please roll back the snark and flamebait in your comments? It has been upticking again for quite a while, to the point where notice I'm bracing myself when I see your username in threads.
Since you've adjusted this in the past, I'm sure you can do so again, and we'd appreciate it. We like that you're here, but need you to stay within the guidelines.
Antares were the first ones: https://www.energy.gov/articles/department-energy-celebrates...
And closely followed by Valar Atomics two weeks later: https://www.energy.gov/articles/department-energy-celebrates...
Actually this guy achieved criticality before either of them: https://i.imgflip.com/a0w01q.png
TRISO fuel so.. pebble bed? Is there a reluctance to market on this? The Chinese were all-in.
Great to see engineering deliver on time. I wonder if Rolls Royce will also have a smooth ride. It's a PWR.
Prismatic (or cylindrical) TRISO also makes sense. There are lots of potential problems using pebble beds (circulation, grinding), whereas doing regular refuelling cycles avoids them, in exchange for down-time to refuel.
TRISO increases fuel cycle costs. It's harder to make, harder to dispose of, and (IIRC) uses higher enrichment.
The positive schpiels say it gets higher utilisaton ("burn") of the fuel inside the micropellets, so it may be HEU, but there's more taken out so less made overall.
I'm unsure where the H in HEU comes from, probably nasty sources, and probably nasty radiochemistry.
The Rolls Royce modular reactor update page [1] leaves me scratching my head as to where they are, it seems they've passed some really hard UK regulation though, maybe the official source is not the best:
[1] https://www.rolls-royce-smr.com/our-progress
From the article: > We said criticality in 2026, electricity production in 2027, and power to the warfighter in 2028.
Are there any other examples of land-based militaries using nuclear power? Seems kind of like since they can't talk about the energy transition or w/e this has to be a military thing instead.
That's originally what the SL-1 reactor was meant for. It was also developed at Idaho Falls.
Instead of parking diesel generators up at Arctic radar stations (and other remote locations), we'd use a nuclear reactor, which is a logical choice.
The problems were:
1) one control rod could send the entire reactor prompt critical
2) rods could get stuck, requiring that they be "exercised" very carefully as to prevent them from making #1 happen
3) this maintenance was being done by a man in his early 20s who had been sleep deprived and received a phone call before his shift from his wife asking for a divorce
The result was the only immediately-fatal reactor accident in American history.
Glad to see that we're getting over this and moving forward with the concept. Only took us 60+ years...
"Stalin is proud to support the rebirth of Soviet Russia’s nuclear industry and ensuring soviets have access to affordable, reliable and secure energy for generations to come". Always mention the fearless leader.
Congrats to everyone involved. This is a pretty awesome milestone
To add a bit of context there were 11 companies participating in program and only 2 achieved critiality, and the deadline included in "DOE Reactor Pilot Program" was "July 4, 2026", and Aalo Atomics is the only one that might also make it in time.
Sigh, everything is being done for political purposes, now Dear Leader Donny can proclaim on the quartermillenial celebrations that "we achieved a nuclear milestone!". And maybe add that this is possible because of his nuclear physics genius abilities.
I wouldn't even be surprised if the achievements are like "Full-Self Driving", announced hastily with boasts and then slowly revealed to be full of Elon.
2 replies →
I am still quite confused on the scientific consensus:
Should we double down on renewable energy and solve its issues with lots of batteries or should we invest in next generation nuclear energy?
Both at the same time?
Does anyone know?
Both at the same time. I don't see how putting all our eggs in a single basket benefits us.
China does: all of the above, where it makes sense.
Renewables and batteries to keep your AC, workplace EV charger, stove, pool heater and (since recently) green ammonia producer going, nuclear to prevent e.g. aluminium smelters from seizing up.
Also the cheapest way to make renewables work 24/7 is to build HVDC lines - they cost as much as a highway per unit length and even undersea cables would deploy for less and faster than equivalent nuclear.
The total length of HVDC lines just in China is currently more than 40k km, so they've literally deployed enough of them to wrap around the globe.
China is also still building coal and has passed Europe and will (if they don’t change course) soon pass the US and Canada and the other big ones on a per capita emitter basis. They already passed everyone as top emitter in an absolute sense.
https://ourworldindata.org/grapher/co-emissions-per-capita
Not saying they’re not also building renewables and nuclear, but it seems like the policy is more “build anything and everything to satisfy demand” than a focused effort.
BTW: if you look at US emissions, the data center bubble hasn’t had much if any effect. They are still trending down. There’s reasons to dislike that industry but I’m sick of the mindless echo chamber doom on that issue. They’re not that significant in the grand scheme of things.
3 replies →
Government should tax / provide incentives based on negative externalities such as environmental impact and let the free market decide
https://unece.org/sites/default/files/2022-04/LCA_3_FINAL%20...
I think a low carbon mix will result in the cheapest, most reliable and cleanest energy grid.
If your location already has a well-run nuclear energy sector (Finland, Sweden, South Korea): invest in nuclear energy.
If you don't: stick to renewables.
And it also depends on what you mean by "we". As a Dane, I don't think us Danish taxpayers should invest in nuclear energy, but I'm perfectly happy that private Danish investors invest in Seaborg/Saltfoss and Copenhagen Atomics.
When it comes to avoiding the worst impacts of the current catastrophic path we’re on, “nothing will work, but everything might”.
Do it all.
Nuclear is not on a trajectory to do more than supply a minor amount of world energy. A (say) 10% nuclear, 90% renewable world is not an easier challenge than a 100% renewable world -- the intermittency/seasonality issues aren't eased by having 10% nuclear running as baseload, and keeping it as backup makes its cost per kWh explode.
Nuclear really has to go big (supply most of the world's energy) or go home. But supplying most of the world's energy means burner reactors are inadequate -- there isn't enough cheap uranium. Burner microreactors have even worse neutron economy, so this argument applies even more so to them.
1 reply →
It's more of an engineering call than something that can be purely determined from inductive reasoning. I think most engineers working in the space would say "both" are needed, but partisans exist on both sides.
That's a political and economic question, not a scientific one. Science can provide input information, but the decision involves weighing all sorts of facts and considerations outside the scope of science.
Exactly. Waiting for a scientific consensus on a question that is very clearly not posed as a scientific question is oddly cultish
We're gonna need portable energy storage regardless of energy source, it's battery vs fuel. There is no such things as battery vs atomic core.
Nuclear partisans like to call renewables ideological, but I think this is another example of "the accusation is a confession".
The empirical evidence has nuclear being uncompetitively expensive. The current focus on variant reactor designs appears to be something of a Hail Mary attempt to get around this sad state of affairs.
You sometimes see them making an argument about energy density, which goes back to Vaclav Smil. But Smil used this argument to massively mispredict how solar would be go in the market. We don't hear him much anymore.
Nuclear advocates increasingly resort to conspiracy theoretic reasoning to explain away the failure of their technology to compete. This should be a red flag.
> The empirical evidence has nuclear being uncompetitively expensive.
France nuclearized 75% of its grid in the 1980s while the solar folks were faffing around. It's not a cost issue, it's that anti-nuclear folks have choked out the industry.
We need to take the boot off the neck of nuclear. Wind and solar aren't an avenue to moving up the tech tree of civilization, which will involve using vastly more power.
12 replies →
>The empirical evidence has nuclear being uncompetitively expensive
I have a solution, take the subsidies spent on "renewables" and put them into nuclear! Easy peasy!
2 replies →
next generation nuclear energy = fusion
Fusion's main accomplishment will likely be to make fission look cheap in comparison, due to fundamental issues of power density in the nuclear island. Why make a huge complex low power density radioactive thing when you can make a much smaller simpler high power density radioactive thing?
Both.
We should be investing in all non carbon emitting sources and we should have been doing it since the 1970s when we figured out pretty conclusively that this would be a problem.
Instead we had right wing fossil fuel shills on one shoulder and unscientific woo woo greens on the other, the net effect being that we kept burning more carbon. We still have them, Trump with “beautiful coal” and greens now opposing even solar power and batteries, but climate change is no longer possible to ignore. Some still manage it but those people are nuts.
If we hadn’t stopped improving nuclear we’d probably have emitted half the CO2 we have. It would have become cheaper and safer and more scalable and then when China industrialized they would have copied that instead of burning so much coal.
France with its nearly zero carbon grid is the existence proof.
It wasn’t until the 2010s that solar and wind became grid scale in a big enough way to matter. That was too slow.
Whether someone is at least open to nuclear power is my litmus test for whether they take climate change seriously.
I do. If we hit 600, 800, 1000 ppm CO2, which is possible if the world keeps developing on the back of fossil fuels, we are entering existential risk territory. Earth has had those CO2 levels before, and higher, but our species was not alive then.
We already passed the FAFO threshold for ppm CO2 and now we will FO. But that’s not X-risk yet. I’m talking about the next threshold, which may start around 600 but really kicks in near 1000. This is where you actually start asphyxiating. You get lowered IQ and impaired judgement to a small degree, but across the globe at a time when we really don’t need it.
Other than "not light-water", what type of reactor is it?
Graphite-moderated core, passively cooled with sodium filled heat pipes:
https://antaresindustries.com/
It also uses a Brayton cycle generator with nitrogen instead of steam.
(See 03, 04, 06 in their schematic outline.)
Is anyone working in the US on a waste solution that isn’t a big hole with a straight out of cyberpunk sci-fi warning plaque?
The French reprocess and recycle fissile material but that’s kind of a gnarly industrial process. Still they do it and it works.
The long term solution is to create a second kind of reactor that has a higher burn fraction which means a more fuel efficient fast reactor. Those would be, ideally, the big base load plants if we did this rationally.
I don't see the issue with dry cask storage medium term, and deep geological storage long term. Spent fuel isn't really that dangerous once it's been cooled down and for a couple decades before putting it in the ground, to the point that there are far more dangerous natural things you can dig up.
What concerns me is that 250 years of fossil fuel energy continues to store its waste products in my lungs and the water I drink. That's the issue we need to solve with urgency.
Europe has about 60,000 tons of nuclear waste storage[1], so lets say the global nuclear waste quantity is 2-3x or 120,000 to 180,000 tons. That sounds like a lot, however it's less than 2 weeks of coal deliveries to a coal plant (at 1 train of 115 cars each with 116 tons of coal = 13,340 tons delivered per day[2]). To take another approach, the average landfill size is 600 acres[3].
The "eh, just bury it" approach is really not a bad one. Its not even that much stuff to bury
[1] https://worldnuclearwastereport.org/
[2] https://www.eia.gov/todayinenergy/detail.php?id=16651
[3] https://www.colorado.edu/ecenter/2021/04/15/hidden-damage-la...
I thought something like 30 tons per Gwatt capacity per year was the ballpark for high level waste without reprocessing? How are you arriving at a 120,000 ton estimate?
3 replies →
Fast neutron reactors can also "burn" waste from other reactors, the "ashes" are radioactive for only 300 years, there is no need for special storage after that. Untreated waste has to be kept in storage for around 100K years before it reaches safe levels of radioactivity.
Other than marketing propaganda, there isn't much real information about Mark-0. I'm assuming it's a sodium cooled, slow and hot pebble bed reactor. Hot pebble beds are well known but one with sodium cooling appears to be a first.
Why slow sodium? You get all the risks associated with sodium with none of the benefits of fast neutrons. There are operational, electricity producing, fast sodium reactors which do make some sense. I can't say the same for Mark-0.
IMO, the long term solution will be to simply launch the waste into space. With low enough launch costs the extra mass needed to armor the waste against accidents becomes tolerable.
A much better, safer, and cheaper idea is dropping suitably packaged waste on the subducting side of the Mid Pacific Subduction Zone. It’d be inert long before seeing daylight again…
The only downside is the “waste” is quite valuable. MSRs can also use it, and their waste is only dangerous for ~300 years.
1 reply →
Economically absurd, much more expensive than reprocessing or fast waste burning reactors.
15 replies →
Probably not worthwhile. If you just leave it in orbit you're going to have to track it and worry about debris/micrometeoroid strikes. The ideal would be to stick it in some permanently shadowed crater on the Moon, it'd be a stable environment without wild temperature swings and much lower risk of somehow ending up where people are. But that's a long way to go and a lot more risk to take for now.
1 reply →
Unless you live in Sci Fi future where space travel is magically free, this is a pretty bad deal since sending a pound of spent nuclear fuel out of earth orbit takes 50+ pounds of fuel. Sending all the spent nuclear waste into space would be something like 10 million tons of fuel.
1 reply →
Can't wait for one of those launch rockets to explode in the atmosphere!
2 replies →
Haven't you seen https://en.wikipedia.org/wiki/Space:_1999 ?
4 replies →
> "The Trump administration is proud to support the rebirth of America’s nuclear industry and ensuring Americans have access to affordable, reliable and secure energy for generations to come."
> "The demonstration and the licensing pathway it establishes represent a key step toward deploying electricity-producing microreactors for U.S. military installations by September 30, 2028."
So which is it? Power to the people or power to the military? This microreactor concept doesn't seem very well suited for commercial use.
Why would microreactor concepts not be suitable for commercial use? History is overwhelmed with examples of large, rare and expensive tech being produced in small cheap packages and becoming massive commercial successes that make the old way look primitive.
> Why would microreactor concepts not be suitable for commercial use?
Crippling diseconomies of scale.
Because large scale production is generally more scalable and efficient. And you probably don't want dozens of "microreactors" scattered across cities.
12 replies →
"Antares is a nuclear fission energy company developing compact microreactors for defense and space applications"
[dead]
That's just what we needed! Nuclear autotune.
Can you please roll back the snark and flamebait in your comments? It has been upticking again for quite a while, to the point where notice I'm bracing myself when I see your username in threads.
Since you've adjusted this in the past, I'm sure you can do so again, and we'd appreciate it. We like that you're here, but need you to stay within the guidelines.
https://news.ycombinator.com/newsguidelines.html
Sure.
I never do flamebait and rarely do snark tho (usually only after several increasingly futile exchanges).
Flippant comments (like the autotune one) and/or sincerely held even if unpopular opinions, I'll stoop to, yes.
1 reply →
We need progress, not a decade per step.
That distinction matters because nuclear.
Let that sink in for a moment.
(psst autotune is made by a company called Antares)