Fusion Discussion Thread

[JoeSchmuckatelli]

Here's an article with more information on the NIF accomplishment.

 

Nuclear-fusion lab achieves ‘ignition’: what does it mean? (nature.com)

The facility used its set of 192 lasers to deliver 2.05 megajoules of energy onto a pea-sized gold cylinder containing a frozen pellet of the hydrogen isotopes deuterium and tritium. The pulse of energy caused the capsule to collapse, creating temperatures only seen in stars and thermonuclear weapons, and the hydrogen isotopes fused into helium, releasing additional energy and creating a cascade of fusion reactions. The laboratory’s analysis suggests that some 3.15 megajoules of energy was released — roughly 54% more than the energy that went into the reaction and more than double the previous record of 1.3 megajoules.

...

NIF scientists readily acknowledge that the facility was not designed with commercial fusion energy in mind — and many researchers doubt that laser-driven fusion will be the approach that ultimately yields fusion energy. But Campbell believes that its latest success could boost confidence in the promise of laser fusion power and ultimately open the door to a new programme focused on energy applications. “This is absolutely necessary to have the credibility to sell an energy programme,” he says.

...

The engineering challenges faced by NIF are different from those at ITER and other facilities. But the symbolic achievement could have widespread effects. "A result like this will bring increased interest in the progress of all types of fusion, so it should have a positive impact on fusion research in general,"

 

Edited December 13, 2022 by JoeSchmuckatelli

[kerbiloid]

9 minutes ago, JoeSchmuckatelli said:

The facility used its set of 192 lasers to deliver 2.05 megajoules of energy onto a pea-sized gold cylinder containing a frozen pellet of the hydrogen isotopes deuterium and tritium

A clean neutron bomb.

[JoeSchmuckatelli]

47 minutes ago, kerbiloid said:

A clean neutron bomb.

Yep

[mikegarrison]

It's important to note that the lasers delivered 2 megajoules of energy to the pellet, and the pellet released 3 megajoules of energy, but the energy required to feed the lasers was more than 400 megajoules. So ... not exactly a positive energy output.

Edited December 14, 2022 by mikegarrison

[JoeSchmuckatelli]

5 minutes ago, mikegarrison said:

It's important to note that the lasers delivered 2 megajoules of energy to the pellet, and the pellet released 3 megajoules of energy, but the energy required to feed the lasers was more than 400 megajoules. So ... not exactly a positive energy output.

The director admitted this during the presentation. 

The 'new' is that for the first time at the pellet they were strongly energy positive.  It was here that she told the press that one of the reasons they were seeking funding is that this was done by lasers that are effectively '80s technology. 

 

There is A LOT of efficiency to be achieved before even thinking about developing it into a power plant 

[mikegarrison]

The other thing is that yes, deuterium is available in the ocean. But it takes a lot of energy to separate out the "heavy water" from the regular water. And then you have to electrolyze the water in order to get the hydrogen by itself.

In order for fusion to be a viable power source, it has to generate more power than it takes for ignition, but also more power than it takes for creating the fuel pellets.

[StrandedonEarth]

So we have this fancy fission power, and hoping to get fusion to be an energy provider. And all in order to heat water to make steam to turn turbines which drive generators. How 19th Century. That's what, 30% efficient? Maybe a bit more  if the low-grade waste heat is put to use? But hey, when you have gobs of energy coming out, you can afford to waste some, like the early steam engines...

Are there any ways to more directly convert the high-energy photons and atomic particles flying out of a nuclear reaction into electricity? Charged particles flying though a magnetic field should create a current somewhere, if I recall my physics correctly? I suppose it's easier to just absorb all this stuff into something that'll heat up, but I can't help but wonder if there's a more direct way to create electricity. Apparently thermocouples can't extract that much, although it's enough to power robotic probes...

 

 

[HebaruSan]

50 minutes ago, StrandedonEarth said:

Charged particles flying though a magnetic field should create a current somewhere

But isn't it mostly neutrons?

[JoeSchmuckatelli]

1 hour ago, mikegarrison said:

The other thing is that yes, deuterium is available in the ocean. But it takes a lot of energy to separate out the "heavy water" from the regular water. And then you have to electrolyze the water in order to get the hydrogen by itself.

In order for fusion to be a viable power source, it has to generate more power than it takes for ignition, but also more power than it takes for creating the fuel pellets.

The video I link above does go into this, too (for those who want more on what Mike's referring to).  One of the problems with shutting down nuclear fission reactors is that the deuterium and tritium are most easily obtained from nuclear reactors and a healthy nuclear energy industry.  Tritium is particularly problematic as the supply is currently very low. 

53 minutes ago, StrandedonEarth said:

Are there any ways to more directly convert the high-energy photons and atomic particles flying out of a nuclear reaction into electricity? Charged particles flying though a magnetic field should create a current somewhere, if I recall my physics correctly? I suppose it's easier to just absorb all this stuff into something that'll heat up, but I can't help but wonder if there's a more direct way to create electricity. Apparently thermocouples can't extract that much, although it's enough to power robotic probes

Apparently the guy who made the video above is visiting a commercial effort that is trying to get away from steam turbines...  Video supposed to be out next week. 

 

Of course - now I'm seeing why @HebaruSanwanted to split the topic: I'm having trouble keeping up with which technology we are talking about.  (Mike's on the NIF topic and Stranded is on the Tokamak / magnetic plasma topic 

[kerbiloid]

2 hours ago, StrandedonEarth said:

And all in order to heat water to make steam to turn turbines which drive generators. How 19th Century.

Didn't you think that Arcanum was a fantasy game? No, it was sci-fi.

Most of human weapons are still a throwing of pieces of rock at each other done by high-tech methods, so are we in stone age?
They were doing it poorly and unknowingly, while the modern humans are able to use the force of science.

2 hours ago, StrandedonEarth said:

That's what, 30% efficient?

3/400 = 0.75%

2 hours ago, StrandedonEarth said:

Are there any ways to more directly convert the high-energy photons and atomic particles flying out of a nuclear reaction into electricity? Charged particles flying though a magnetic field should create a current somewhere

This is how the aneutronic fusion will work.

But it requires much greater temperatures, so can't be the first step.
And its fuel are not just deuterium, but either boron (which is more rare than deuterium), or helium-3 (which can be made from the oceanic lithium, which is still more rare), or nitrogen/carbon which produce a lot of parasite neutrons.

So, the aneutronics is for board reactors, whil deuterium is for everywhere in the Univerese where there is some traces of water (ice).

3 hours ago, mikegarrison said:

The other thing is that yes, deuterium is available in the ocean. But it takes a lot of energy to separate out the "heavy water" from the regular water. And then you have to electrolyze the water in order to get the hydrogen by itself.

In order for fusion to be a viable power source, it has to generate more power than it takes for ignition, but also more power than it takes for creating the fuel pellets.

Deuterium releases 80 kt/kg, so I guess its enough not only to ionize some piece of water, but also to make it shine as a sun.

[Pthigrivi]

Like this is cool and all but its such a white elephant. Sorry to say but same with nuclear. If you cant compete dollar/kw with solar, wind or grid scale batteries its just not going to happen. 

[mikegarrison]

16 minutes ago, Pthigrivi said:

Like this is cool and all but its such a white elephant. Sorry to say but same with nuclear. If you cant compete dollar/kw with solar, wind or grid scale batteries its just not going to happen. 

You need to consider the energy density, though. Solar and wind have very large footprints/MW. A nuclear plant is much more compact.

[Jacke]

2 minutes ago, mikegarrison said:

You need to consider the energy density, though. Solar and wind have very large footprints/MW. A nuclear plant is much more compact.

An excellent point.  Can't remember the source, but I recall an estimate that the United Kingdom to be powered by offshore wind power would need a belt of windplants about 70km thick all around the island of Britain.  There's also the storage need to buffer wind and solar power, which isn't trivial, would demand a lot of high-cost rare materials, and would also take up a lot of area.

Also, fusion power plants will be about the same size with many of the same features as a fission plant.  They will become irradiated from all the free neutrons generated, so when decommissioned, they will need to go through much the same process as what's done with fission plants.

The fuel, deuterium, tritium, and lithium, will be costly and difficult to extract.  (A regular hydrogen fusion plant is much much harder to make, as in massively higher levels of energy need.  It ain't going to happen for centuries more.)  I personally think the best fission designs, especially including the use of Thorium, is a better way to go.

[Pthigrivi]

4 hours ago, mikegarrison said:

You need to consider the energy density, though. Solar and wind have very large footprints/MW. A nuclear plant is much more compact.

Maybe? But land is already baked into the capital cost of solar and its LCOE  is like 50$ Mwh right now. Battery storage is at 150, already less than nuclear and falling. Does anyone really believe fusion will be cheaper than that? It just makes so much more sense to network a bunch wind and solar to storage and balance local drops with HVDC.

Edited December 14, 2022 by Pthigrivi

[mikegarrison]

32 minutes ago, Pthigrivi said:

Maybe? But land is already baked into the capital cost of solar and its LCOE  is like 50$ Mwh right now. Battery storage is at 150, already less than nuclear and falling. Does anyone really believe fusion will be cheaper than that? It just makes so much more sense to network a bunch wind and solar to storage and balance local drops with HVDC. This all reminds of the hyperloop scam whose sole purpose was to delay and derail much more sensible high speed rail projects.

The problem is trying to scale up. At some point, you just run out of available (and appropriate) space to put more turbines and solar farms.

It's similar to the problem with hydro, where once you have dammed the available rivers, you hit the limit of the available power.

[kerbiloid]

https://sturgeonshouse.ipbhost.com/topic/1620-fourth-generation-nuclear-weapons/

So, they just declared officially the work on the 4th gen nukes.

0.75%  is pathetic for a powerplant, of course.

Probably they did it due to the news about the BN-800 using MOX fuel https://en.wikipedia.org/wiki/BN-800_reactor 
and the current events in the energetics and powerplants, to decrease the hydrocarbon prices by an inspirational "I got the powah!" scream.

P.S.
The linked pdfs are also about the AM and MMH hype actual reasons.

Edited December 14, 2022 by kerbiloid

[Pthigrivi]

5 hours ago, mikegarrison said:

The problem is trying to scale up. At some point, you just run out of available (and appropriate) space to put more turbines and solar farms.

It's similar to the problem with hydro, where once you have dammed the available rivers, you hit the limit of the available power.

Nah I dont buy it. Denmark is getting 56% of their energy from wind and Germany is getting 9% from solar. You only need about half and half. There are a lot of parking lots and rooftops out there.  If you can scale up storage as nuclear ages out you’re fine. Rather than dump subsidies into something that will never be cost competitive put it into upgrading a grid that can quickly and efficiently shuffle power to where its needed. 

Edited December 14, 2022 by Pthigrivi

[Codraroll]

7 hours ago, StrandedonEarth said:

So we have this fancy fission power, and hoping to get fusion to be an energy provider. And all in order to heat water to make steam to turn turbines which drive generators. How 19th Century. That's what, 30% efficient? Maybe a bit more  if the low-grade waste heat is put to use? But hey, when you have gobs of energy coming out, you can afford to waste some, like the early steam engines...

Are there any ways to more directly convert the high-energy photons and atomic particles flying out of a nuclear reaction into electricity? Charged particles flying though a magnetic field should create a current somewhere, if I recall my physics correctly? I suppose it's easier to just absorb all this stuff into something that'll heat up, but I can't help but wonder if there's a more direct way to create electricity. Apparently thermocouples can't extract that much, although it's enough to power robotic probes...

I know of one method that's being explored, although it sounds a little insane. And by that, I mean that the name alone should send shivers down the spine of anyone who dabbled in physics at a high school level or above:

Magnetohydrodynamics. The science of the electromagnetic properties of electrically conducting fluids.

The concept is fairly simple. Take a magnetic fluid, and move it. This induces a current in wires, like moving a solid magnet in an ordinary dynamo.  The plasma generated in a fusion reactor is a suitable medium. This essentially turns the reactor output directly into a generator, which means you'll skip all the inefficient middle steps between heat and electricity. The generator efficiency can be very high, up to 60-70% or so.

The science, however, is a bit complex. Take all the problems associated with calculating the movement of fluids, like the Navier-Stokes equations, and sprinkle in all the intuitiveness of Maxwell's equations on electromagnetism. They influence each other. Have fun.

And the practicalities are nuts. After all, you're working with plasma, which tends to be rather hot. It's also moving fast, which creates all sorts of funny abrasion problems. And of course, this being nuclear fusion, there's intense radiation everywhere too. You might get slag deposits here and there too, which interrupt the flow, and then Navier-Stokes rears its ugly twin heads once again.

But the potential is awesome. If you can build it without something melting and warping.

[kerbiloid]

24 minutes ago, Pthigrivi said:

Denmark is getting 56% of their energy from wind

Quote

Denmark

Danmark (Danish)

Population
• M10 2022 estimate	5,928,364[11][N 6] (114th)

Area
• Total	42,943[9] km2 (16,580 sq mi) (130th)

Spanning a total area of 42,943 km² (16,580 sq mi),^[9] it consists of the peninsula of Jutland and an archipelago of 443 named islands,^[16] of which the largest are Zealand, Funen and the North Jutlandic Island. Denmark's geography is characterised by flat, arable land, sandy coasts, low elevation, and a temperate climate. 

Population 6 mln. 
Totally consists of coastline shaped into several hundred islands and the major peninsula.
A moderate climate with permanent winds, surrounded by flat water.

Yes, Denmark can.

P.S.
And Greenland. Not that I doubt it's the largest part of Denmark.

Edited December 14, 2022 by kerbiloid

[Pthigrivi]

1 hour ago, kerbiloid said:

Population 6 mln. 
Totally consists of coastline shaped into several hundred islands and the major peninsula.
A moderate climate with permanent winds, surrounded by flat water.

Yes, Denmark can.

P.S.
And Greenland. Not that I doubt it's the largest part of Denmark.

Right which is why they’re already there. Most regions have either coastlines or ridgelines. We have an existing, proven, cheap way to provide power starting now and maxing out in 10 years vs waiting 10 years for something that may or may not work with a ludicrous price tag. But its a shiny object and allows the politicians to kick the can down the road so its what we focus on. 

[Codraroll]

27 minutes ago, Pthigrivi said:

Right which is why they’re already there. Most regions have either coastlines or ridgelines. We have an existing, proven, cheap way to provide power starting now and maxing out in 10 years vs waiting 10 years for something that may or may not work with a ludicrous price tag. But its a shiny object and allows the politicians to kick the can down the road so its what we focus on. 

 The problem with creating a grid based entirely on renewables is that it's quite smooth sailing up to, say, 80%, and from there the difficulty of replacing the remaining non-renewables increases exponentially. The demand for electricity goes up and down all the time, and with renewables, so does the supply. Preventing a gap from forming in the wrong direction is the hard part (managing a surplus is tricky too, but easier). You need some sort of storage that works long-term, to give you juice when everyone needs more electricity than the turbines and PV panels don't quite produce enough. This remains an unsolved challenge on a grid-wide scale. Or rather, the "storage solutions" we do have (fossil/radioactive fuels) are not renewable.

There's batteries, of course, but those are massively expensive and can't store power indefinitely. They are good for evening out variations from hour to hour, maybe day to day, but on a longer-term basis they are inadequate.

Hydroelectric reservoirs are wonderful for energy storage as they can store oodles of energy for a long, long time. However, they require the right quirks of geography, their capacity is difficult to scale beyond a certain point, and long-term forecasting is difficult. The amount of water in the reservoirs is limited by the local rainfall or snowmelt, and it's a bit of an art to determine when to run the powerplants and when to hold back. On the one hand, you want to have remaining water in the reservoirs for when you need it later. On the other hand, you also want to have enough idle capacity to absorb the next rainfall, so you don't have to send water to the sea when the reservoir goes full. 

Other kinetic solutions, of the "big block of concrete in a mineshaft" variety, are completely off the table. Just try to do the math on how much energy you can store in a one-ton block suspended by a 100 m cable.  To put it like that, it's far from enough to justify the maintenance cost of the pulley arrangement.

Then there's the solutions that involve some kind of chemistry. Typically hydrogen electrolysis, or methane production. They work, but they are hellishly inefficient. If memory serves correctly, you put 6 kWh in for every 1 kWh you get back, and I'm not sure if that includes the generator efficiency. And then there's the maintenance of the electrolysis plant.

So unless a revolution of sorts happens in batteries or fuel synthesis, some base load production will be required to bridge the gap between what renewables can produce on a bad day and the demand for electricity on that same bad day. Some plant that can be fired up to create energy when the other methods don't give enough. That's where nuclear power plants - and to be realistic, probably gas-fired power plants, at least for a long while - will retain their niche for many years to come.

[kerbiloid]

Denmark is 6 mln.

Netherlands is 18 mln, Germany is 83 mln.

In case of calm, they can just throw a couple of wires to the neighbors.

It would be a problem for Germany to distribute their 9% (83 * 0.09 = 7.5 mln) wind power between others and keep something for themselves.

[Pthigrivi]

2 hours ago, Codraroll said:

 The problem with creating a grid based entirely on renewables is that it's quite smooth sailing up to, say, 80%, and from there the difficulty of replacing the remaining non-renewables increases exponentially. The demand for electricity goes up and down all the time, and with renewables, so does the supply. Preventing a gap from forming in the wrong direction is the hard part (managing a surplus is tricky too, but easier). You need some sort of storage that works long-term, to give you juice when everyone needs more electricity than the turbines and PV panels don't quite produce enough. This remains an unsolved challenge on a grid-wide scale. Or rather, the "storage solutions" we do have (fossil/radioactive fuels) are not renewable.

No I think these are all the real issues, and honestly I'd take 80% off the bat easily. That would be fantastic. I agree on most of the questions about storage, except that battery storage is already cheaper than adding new nuclear and is projected to fall drastically over the next couple of decades. This is also a big zone where regional high voltage DC would be hugely valuable for longer range transmission. I might have socked in, windless rain in Boston but if wind is blowing on the cape and the sun is shining in PA and Quebec you can bring power in to cover temporary lulls in production and take a lot the load off storage. You could probably even send power west in the morning to cut an hour or so off that pre-dawn rise in demand. It would also be wise to encourage most EV charging to happen at places of work during the day when the sun is shining rather moving from battery to battery charing at home at night. All of this would encourage regions to build in over-capacity so they had room to share, but when wind and solar cost 1/3 what nuclear does you could double max output and still come out ahead. Of course you may have weird dead zones that still rely on nuclear or fusion someday to fill in around the edges and thats fine, but it's more of a stopgap than the main solution. 

Edited December 14, 2022 by Pthigrivi

[mikegarrison]

Denmark is a very small country that is almost all coastline. Switzerland is a very small country that is almost all mountains (and has 60%+ hydro). Iceland is a very small country right on the mid-Atlantic rift and gets lots of power from geothermal sources. These are not solutions that will work for most places.

Germany getting 9% from solar is great, but they have been pushing solar really hard for more than a decade now and they are only at 9%.

That's my point -- wind and solar are great, but for most places they are limited to how much they can scale up. Come back and tell me "I told you so" when Germany is making 90% from solar instead of 9%, OK?

Edited December 14, 2022 by mikegarrison

[JoeSchmuckatelli]

@Pthigrivi

5 minutes ago, mikegarrison said:

Germany getting 9% from solar is great, but they have been pushing solar really hard for more than a decade now and they are only at 9%.

[In Germany] the national average for the year was hours of sunshine a day or 158 full sunny days.

The number of sunny days in Germany by federated state, by year and month (ru-geld.de)

German 'flip-flops' on Nuclear Power.

EXPLAINER: Why Germany is delaying its nuclear shutdown | AP News

Unsurprisingly, the flatter, coastal adjacent areas are best for wind - with much of the country 'not ideal'

Global Wind Atlas

The energy density issue (how much land you need to produce corresponding amounts of power) is a non-trivial issue:

INFOGRAPHIC: How Much Power Does A Nuclear Reactor Produce? | Department of Energy

Need over 400 modern utility-scale turbines, or over 3 million solar panels to equal the output of one average nuclear power plant.