I couldn't agree more. Once you realize that energy is the fundamental unit which powers everything else in the economy, not only from every movement of ourselves to those of our machines as well, you realize the more we advance in our ability to produce more and more energy at cheaper and cheaper costs in increasingly reliable ways, the more we can accelerate, without exception, every other industry.
There is ~zero expectation in the scientific community that fusion is going to be cheap at scale. It might eventually be cheaper than fission due to several factors. But, even that’s looking a long way off.
> It might eventually be cheaper than fission due to several factors.
This surprises me, for a number of reasons.
A fission reactor can be operated safely by a bunch of people with baccalaureates, whereas a fusion reactor will need PhDs, as I understand things. Also, its capacity factor will not be as good as that of fission reactors.
The waste from fission reactors can be made pretty small by reprocessing and in-reactor transformations. The radioactive waste from fusion is whole reactor vessels, which are large and difficult to handle (=expensive).
At commercial scale fusion reactors need ancillary fission reactors to manufacture the tritium they require. So you have two reactors instead of one.
Other factors look similar, except that fusion will carry an investment risk premium because of its novelty and complexity.
So under equivalent regulatory regimes it seems to me that fusion would cost as much or more than fission.
Can you explain why it might eventually cost less?
Significantly less security concerns. No need for a massive containment vessel or massive redundant safety systems. Likely cheaper fuel and no long term high level nuclear waste. A smaller percentage of the reactor becomes contaminated. Lower insurance costs.
D is already cheap and even used by fission reactors. Extracting T from the blanket is presumably inexpensive, and one of the things ITER will test, but that’s an unknown. https://en.wikipedia.org/wiki/Breeding_blanket The real question is how expensive the physical reactor is going to be to build and maintain and does that offset the other savings. It’s expected for that cost to drop over time which is why it’s possible to eventually be cheaper than fission.
Finally, DT is easiest to achieve at a 50/50 ratio but DD fusion still takes place. So a lower mix of T is viable once very high Q values are possible, thus eventually zero T designs should be viable.
If you need a bunch of people with PhDs to operate a reactor, then you won't have a reactor. Not only does it mean that staffing is expensive and difficult, but also that it won't be reliable or predictable. If it is predictable, then steady state operation should be offloaded to computers.
How so? Unlimited, non-radioactive fuel and inherent safety of the system alone could tip this scale pretty severely in favor of fusion once it becomes energy-positive. And remember, once that happens, investment is going to be through the roof, which will accelerate progress. Either the "scientific community" (whatever that means) is either too pessimistic about this, or you've just made this up.
The fusion produces neutrons.[1] That means that at least some parts of the infrastructure can't avoid becoming radioactive. Decommissioning -- at the very least -- is still a problem.
Any actual nuclear physicists want to chime in here?
[1]Yes, the concept of "Aneutronic fusion" exists: <https://en.wikipedia.org/wiki/Aneutronic_fusion>. But read the parts about the required conditions being much more extreme than D-T fusion.
Deuterium is a stable isotope, but Tritium’s half life is only 12.32 years making it quite radioactive.
There is significant effort put into using lithium blankets to create tritium at which point arguably the fuels are lithium and deuterium. But that’s also going to require irradiate the relevant equipment.
Yea, though only about 400grams are used worldwide mostly for self illuminating signs. Which adds up to 12 million dollars per year of demand resulting in such high prices.
Tritium is in the fuel, and it's quite radioactive.
A 1 GW(e) reactor would burn enough tritium in a year that, if that quantity were to be released into the environment, it could contaminate 2 months worth of the flow of the Mississippi River above the legal limit for drinking water.
Tritium containment at a fusion reactor will have to be damned near perfect. This will be a major problem, as tritium permeates through all sorts of things (for example, plastic seals on containment penetrations cannot be used).
Gaseous tritium being significantly lighter than air tends to end up in the upper atmosphere not contaminate the local environment. As it’s beta decay you could have a glass glass jar of the stuff on your desk for years without issue.
Unlike fission power plants there isn’t going to be years worth of the stuff on site. For one thing 5% of the stuff decays sitting around so you want a tight loop of production to consumption. Further, the reactor is holding low density plasma so there is very little inside at any one time.
> Gaseous tritium being significantly lighter than air tends to end up in the upper atmosphere
That's not how it works. A low molecular weight gas anywhere below the homopause remains well-mixed, and does not separate by molecular weight. On Earth, that's anywhere below 100 km altitude.
Yes, but not what I am referring to. 100 miles is a long way up. A large release of Tritium would first quickly gain altitude while in a high concentration before mixing with other atmospheric gasses. For the same reason as hot air from a fire initially rises as a column. After that it’s going to keep mixing with other atmospheric gasses and spreading through literally billions of cubic miles of atmosphere around the globe because unlike fallout it can stay in the atmosphere.
As a beta emitter it’s blocked by just a few feet of atmosphere thus rendering the bulk of it harmless. Eventually, some will combine with oxygen and end up as water, but again most of that just ends up in the ocean.
The quantity of tritium we're talking about here is about 100 kg. That will rapidly be mixed into air within a short distance of the plant. It's not going to form some coherent blob that can penetrate 100 km of atmosphere.
Once in the troposphere, hydrogen of any kind will be oxidized to water within a couple of years, and then rain out. Of more concern would be accident processes that would cause it to be oxidized immediately. For example, any fire or exposure of hot materials to air would cause associated tritium to react.
This is all unrealistic anyway, since the plant will not have 100 kg of tritium on hand at any time. That's about the amount consumed in a year, but the reactor could not afford to have any substantial amount sitting around, decaying, or else the breeding ratio will be too low.
I think we have mostly been talking past each other as I don’t disagree.
Anyway, for a more detailed description of what I was expecting. A least initially it’s going to act just like hot air. Hydrogen’s is 7% the density of air so Tritium is presumably 21% the density of air. Which is similar to air at 2000f without the particulate matter of smoke.
About 100kg should be roughly 500 cubic meters depending on temperature, but a more reasonable limit of ~10kg is still close to 50 cubic meters of gas. If we are talking a sudden release from say a pressurized tank rupturing outside that’s going to from an invisible but mushroom shaped blob and rise. Where a detonations mushroom cloud stops rising as the temperature cools, this thing only slows as it mixes with air which isn’t that fast. The troposphere is only ~8miles up so it’s likely to reach the stratosphere mostly intact.
If we’re talking a venting pipe or something that releases gas more slowly then you get much faster mixing. However, baring the slowest of leaks we are still likely talking going up hundreds of feet at a minimum and more likely miles before it dispersed enough to act like the rest of the atmosphere.
In the absolute worst case, you still get a lot of vertical mixing of the atmosphere from thermals and rapid dispersion from the wind which doesn’t slow down. Within days you’re talking thousands of cubic miles of atmosphere. So, a short term evacuation of those down wind might happen, but they should be able to return in days.
My best guess is the latest "nuclear energy is failing because it's expensive" trend on HN is to blame for this outlook. My take is that it's all poppycock. The ability to make our own little sun is, IMO, transformational for humanity.
The cost of the power plant can easily dominate the cost of the fuel. I build power plants fuelled by waste industrial heat (10-20 MW scale) and even though the fuel is all but free it can be tough to identify economically viable projects.
Nuclear fusion in the existing designs absolutely needs Tritium as one component of fuel, and Tritium can so far only be produced in Uranium reactors, in very small quantities and at an extremely high price.
It was my understanding that fission and fusion both use the same Nuclear Power Plant sized facility.
Fusion just replaces the radioactive bit, you still need steam/electricity conversion/transmission/cooling... it's not like a suitcase you can plug wires into, you still need a massive 'factory' to make electricity, just the one bit is a safer.
I am really not buying the fact that nuclear is expensive because it's nuclear. I think the fears around it, the overregulation and opposition to it make it costly. Obviously, there have been plenty of plants that were profitable.
Also, nuclear fusion is possibly the cleanest energy source we could get. If we touch this, we might have a real path forward.
That just isn't the case. Nuclear (fission) has always been the single most expensive way to generate electricity, and the expense has only increased. Uranium is crazy expensive. Security is very expensive. Spent fuel storage effectively never stops costing, and it isn't ever cheap. If nuclear was simply expensive because of regulations, investors would find a way, and you could not beat them away from building nuclear power plants. But that just isn't where the expense lies. Today it costs $20B to build a nuclear power plant, and that does not include the cost of spent fuel storage or decommissioning. Investors are actually pretty shrewd to stay away from that kind of an investment that always loses. The idea of "electricity too cheap to meter" simply never materialized. Today, electricity generated from solar power is cheaper than electricity generated from nuclear power. The main reason the 110 or so commercial nuclear plants were ever built is that the US military vastly overestimated its need for fuel for bombs.
Thats not accurate at all, Uranium itself is much cheaper than coal / any fuel per unit energy. Some contries have permanent, final storage for nuclear waste, it does not cost any more once created.
Furthermore, not only was solar power borderline non existent when those reactors were built, it is also still intermittent. You are just glossing over the biggest challenge of energy - balancing the powe grid. No-one needs energy if it's only avaliable at the wrong time. Energy storage multiplies cost of renewable electriciry several times over, and no country-scale grid has ever operated on wind and solar.
Lastly, energy is actually cheap - you can see that because we can afford transporting a pair of jeans 4 times across the world in the process of manufacture. We could have had zero-carbon grid since the 70s with nuclear - and France did. Even though France has cheapest energy in EU, suppose energy would be 30% more expensive. So what? We would be so much better off in terms of climate change.
Nuclear has the opposite problem as solar in that it needs high uptime 24/7 to stay reasonably economical. You can easily design a grid following reactor as seen with nuclear subs etc, it just doesn’t save you any money.
24/7 365 grid scale battery backed and thus load following solar runs about 8c/kWh* which is cheaper than nuclear at high utilization. Sure, France’s model of importing and exporting significant chunks of electricity allowed them to ramp up nuclear, but they where exporting power at a loss and utilization still fell into the 80% range.
Excluding the most northern areas is a pretty big issue. Most of Europe is north of 45 degrees north... Yes, Hawai'i and California can be supplied with solar panels cheaply; the UK can't.
Can’t is really just a cost question. 8.2 percent of Germany‘a gross-electricity generation comes from PV solar and their southernmost point is 47°17'N. IMO, that was an over investment, but that’s their choice. Most people in Canada live south of that so we are not talking about that many people.
We are really talking about a handful of countries. The Nordic countries have cheap alternatives in hydroelectric, wind and geothermal energy. Nuclear may have a few niche applications for northern islands etc, but that’s not really significant globally.
PS: 4% of the UK’s electricity comes from solar and their southern tip is a actually quite decent for solar.
I'll respond to your straw man. It isn't about the energy within the thing, the exorbitant cost of Uranium is in mining and refining. No one said anything about coal, but it doesn't need refined, and is cheaply mined... but you've also made a false equivalency, because coal isn't the only competition to nuclear. The sun just shines, wind just blows, water just flows, and the geothermals just produce heat, without any investment or refinement.
If just 10% of the resources poured into nuclear development, which is a cost no one that is pro nuclear wants to tally into the bill, were instead invested into solar energy, nuclear power would not have been able to compete with solar power by 1980.
Nuclear power isn't cheap, unless you ignore the insane R&D that was paid for by tax payers by government mandate and never paid back, unless you ignore the massive cost of construction long before one watt of power is produced, and unless you ignore the massive cost of decommissioning, and unless you ignore the never ending cost of spent fuel storage. It is entirely absurd that you believe once a spent fuel storage facility is built, the costs just disappear. The costs never go away. Maintenance. Security. Testing. It isn't free and it isn't cheap.
You keep repeating this idea thay uranium is expensive, by what metric? Where do you get the idea that its expensive?
If nuclear is so expencive, why does France have cheapest elecrticity in EU? And Denmark /Germany have invested in renewables have expensive electricity.
Looks like I was simplifying. Uranium prices peaked around 2010 for $135/lb., and today is only $35/lb. The break even point for mining uranium is about $50/lb. So the problem in 2010 was that uranium was crazy expensive, but the problem today is it is so cheap, it can't be mined for profit.
But you raise a decent point about what metric we should choose... I meant the cost of the stuff, but there are other metrics, such as clean up costs, because mining uranium is not clean. There is also a human health cost to populations within the proximity of the uranium mine.
French electricity is likely cheap because the French tax payers already picked up the cost of constructing spent fuel storage facilities and power plant construction, and they will ultimately shoulder the burden of the cost of decommissioning. This is just an educated guess, because that is usually how nuclear economics work. Otherwise, the investors that run the plants and sell the electricity would not be interested.
Uranium and even enriched uranium is still reasonably cheap. Fuel rods get expensive, and more critically only using up ~5% of a fuel rod before you need to replace it gets even more expensive. Other reactor designs can use a higher percentage of uranium without reprocessing, but they have other issues. In the end fuel including waste disposal represents about 10% of nuclear reactors operating costs or ~1c/kWh. It’s a significant but hardly gamebreaking cost.
You don't need as much containment as you do for fission, because you don't deal similarly large amounts of highly radioactive isotopes. Consequently, the safety standards required are closer to fossil plants than to nuclear plants, and these safety standards are really what drives the cost of nuclear fission. The steam/electricity conversion/transmission/cooling" are also present in fossil plants, and these are significantly cheaper than fission plants.
Fission’s primary form of shielding is generally large pools of water or other coolant which don’t directly become radioactive. Fusion on the other hand needs to maintain a near vacuum so your pressure vessel is under heavy neutron bombardment. However, small amounts of radioactive materials get dissolved in the fission’s water which the goes on to contaminate the primary coolant loop which increased decommissioning costs. Fusion reactors primarily containment vessels becomes extremely radioactive and all the remote handling equipment also needs decontamination, but it’s unclear if the primary coolant loop will need similar types of decontamination.
Running the numbers the real difference is fission reactors need more protection from the outside world and containment for a potential meltdown. Thus thick though still fairly cheap walls, which generally don’t become radioactive. They last for 50 years and don’t actually cost that much to construct. Fusion however is a vastly more complex device which will also increase construction and decommissioning costs.
In ARC the containment is not under vacuum, the reactor chamber is surrounded by molten salt of fluoride and lithium, and so the neutrons produced travel into molten salt where they collide and produce tritium.
It would help to actually watch the presentations. They’ve solved a lot engineering problems from
Routine maintenance to blanket
Renewal.
ARC reactors due use high temperature plasma in a near vacuum. “The confinement time for a particle in plasma varies with the square of the linear size, and power density varies with the fourth power of the magnetic field,[2] so doubling the magnetic field offers the performance of a machine 4 times larger.”
I am really tired of this line - the taunami killed 18,500 people. The reactor incident killed no-one through radiation and 32 people through physical injuries.
One failure of Banqiao Dam killed an estimated 240,000 people. That's more than all people who have ever died from anything to do with nuclear, reactors and bombs combined.
Air pollution kills about 2,000 people every single day.
Reactor incidents are like plane crashes - they get attention. Fissil fuels are like car crashes - they kill more people every day and noone gives a shit.
Killing people is hardly the only issue. Rendering large tracts of land uninhabitable is extremely expensive. All told 4 nuclear reactors have had major issues, 2 subs and 1 power plant run by the USSR, and then another one very recently by Japan. Plus several near misses.
That’s a significant percentage of total reactors ever built including what was considered a safe design. We could go 1000 years without another incident, but from an insurance standpoint what would you charge a new power plant next to NYC? That means you need them in an a less expensive area, but everyone feels their area is valuable. That causes vast NIMBY issues and heavy regulation.
In theory modern Nuclear should cost less and be both clean and safe, but people gonna people both inside and outside the industry.
> Rendering large tracts of land uninhabitable is extremely expensive
Have you ever been near a coal ash pond? You probably haven't because it is an extreme health hazard to get anywhere near it, as it is full of mercury, arsenic, heavy metals and occasionally radioactive slurry.
There about a thousand of these ponds in the US alone totaling maybe 100,000 acres. Meanwhile all the nuclear power plant waste ever produced could fit into a single large hangar...
Every nuclear accident was completely avoidable, but it’s not clear if future plant operators can avoid making similar mistakes.
The Chernobyl exclusion zone is 1,000 square miles. Fukushima had a much smaller exclusion zone but Estimates of radioactivity released ranged from 10–40%[163][164][165][166] of that of Chernobyl. The significantly contaminated area was 10[163]-12%[164] of that of Chernobyl.[163][167][168]
On 12 October 2012, TEPCO admitted for the first time that it had failed to take necessary measures for fear of inviting lawsuits or protests against its nuclear plants. That’s the core issue not physics.* ... A 2008 in-house study identified an immediate need to better protect the facility from flooding by seawater. This study mentioned the possibility of tsunami-waves up to 10.2 meters (33 ft). Headquarters officials insisted that such a risk was unrealistic and did not take the prediction seriously.The U.S. Nuclear Regulatory Commission warned of a risk of losing emergency power in 1991 (NUREG-1150) and NISA referred to that report in 2004, but took no action to mitigate the risk.[149]https://en.wikipedia.org/wiki/Fukushima_Daiichi_nuclear_disa...
France and the US have a solid nuclear track record, but so did Japan.
I'm really tired of this line as well. Had they failed to contain Chernobyl, much of Eastern Europe would be contaminated for thousands of years.
It is true that today's reactor designs are much safer than RBMK, but I will prefer the reactor can can't go supercritical to one that can any day, especially if it's nearby.
Tsunami and earthquakes are not man generated events, so we can dismiss them. Yes, they killed a lot of people, but cancer kills even more: about 10 millions per year. In part, cancer is caused by contamination of food by radionuclides from reactor leaks (Chornobyl) and nuclear bomb testing.
> In part, cancer is caused by contamination of food by radionuclides from reactor leaks (Chornobyl)
Sorry, this is just misinformation. Residual radiation worldwide from nuclear testing or Chernobyl is minuscule. We wouldn't even be able to detect anything if we didn't have incredibly sensitive instruments.
The sun is a much larger daily source of radiation. Or a banana.
There are not many countries who did nuclear weapon tests and even those that did, did not do it in such numbers. Maybe russia, but I doubt that would push the numbers much.
McBride and his co-authors estimated that individuals living near coal-fired installations are exposed to a maximum of 1.9 millirems of fly ash radiation yearly. To put these numbers in perspective, the average person encounters 360 millirems of annual "background radiation" from natural and man-made sources, including substances in Earth's crust, cosmic rays, residue from nuclear tests and smoke detectors.
The Chernobyl exclusion zone is 30km in radius. It’s not at all clear that serious effects do not extend beyond that, for instance to agricultural lands in Belarus.
Make an efficient fusion reactor of any size, and you can power Fischer-Tropsch plants to synthesize carbon-neutral hydrocarbon fuel for the existing fossil-fuel infrastructure.
I really hope that phase is as short as possible and we don't use it as an excuse to prolong the use of burning crap to generate usable energy. Air pollution is gross.
The problem is not that we are burning hydrocarbons per se. The problem is rather that these hydrocarbons were extracted from the ground and introduced into the short term carbon cycle. The total amount of carbon rises thereby which leads to shifts like an increasing concentraction in the atmosphere and the oceans. These higher levels of carbondioxide in the atmosphere let less heat escape back into space (the atmosphere is normally somewhat transparent at the affected wavelengths but carbondioxide can absorb at that, trapping additional heat in the atmosphere, see [0]), leading to additional global warming (water vapor also traps heat and and made Earth suitable for life as we know it in first place). Higher levels of carbondioxide in the atmosphere also lead to more carbondioxide being absorbed by the oceans which in turns acidifies the water.
We could extract carbondioxide from air, turn it into hydrocarbons and burn that all day/year/century long but producing it from fossil sources is what makes it so bad.
In a nutshell: You taken carbon dioxide from the air, hydrogen produced with a carbon neutral power source and reverse the process of burning oil. Result: hydrocarbon and oxygen. Costs a fair amount of energy and is comparatively inefficient and costly, but it is carbon neutral since burning that produced hydrocarbon will produce as much CO2 as you used to produce it.
I like this. :) I am just amazed how many people fail to see the importance of this. It would _really_ pave the way of the future for humanity if it pans out. Pretty exciting stuff.
