More invested in nuclear fusion in last 12 months than past decade • Hacker News Board

Re: More invested in nuclear fusion in last 12 months than past decade

#491

Post by Schroedingersat » Sun, Jul 24, 2022, 11:21 AM UTC

formerly_proven wrote: post #410

dignick wrote: post #381

Earlier quoted context omitted.

There are several problems with fission (probably fusion too) as I understand it: 1. Cost per MW compared to renewables (~$150 vs ~$40 and falling). Here in the UK the government is promising to subsidise this to make it viable. 2. Construction time - average is 10 years, we don’t have that long to wait. 3. Decommissioning is expensive and a long way in the future. Is that cost built into the cost per MW? How can we…

> 1. Cost per MW compared to renewables (~$150 vs ~$40 and falling). Here in the UK the government is promising to subsidise this to make it viable. You can't directly compare cost per generating capacity, because nuclear, gas, coal etc. are available according to schedule, while most renewables aren't. Adding storage around renewables to make them schedulable raises costs.

Nuclear in the UK has a capacity factor of around 60%. Availability is in the 70-80% range.

Yeah it's (usually) planned, but it's a decently long time in which you need those gas plants.

Why not just build solar instead and fuel those same gas plants with hydrogen or methane you plucked from the air with your $20-30/MWh unscheduled electricity?

Plus, you can get solar and storage as an off the shelf item today as a retail customer for less per watt than recent reactors in UK/France or even USA. 8kW nameplate solar and 16kWh storage capacity is about $10k which matches 1kW of net from eg UK projects of around 2.5GW net for 26 billion pounds fairly closely.

Yeah if you live far north or have a long cloudy month in winter you'll be relying on that gas plant, but so does the nuclear reactor. Plus you'll be dumping 10-20kWh/day into the grid on the good days. Provides a decent incentive to figure out how to store it, and even if you're only getting 5c/kWh for it, it'll pay for replacement in 7-10 years or so when prices have dropped another 50-80% without sacrificing your kilowatt.

Re: More invested in nuclear fusion in last 12 months than past decade

#492

Post by ncmncm » Sun, Jul 24, 2022, 11:22 AM UTC

thrown_22 wrote: post #480

ncmncm wrote: post #446

Earlier quoted context omitted.

Coal is on its way out. It is now cheaper to build a new solar farm to replace a coal plant than just to operate the already built coal plant. It is as cheap to build renewables as to operate an already built and paid for nuke. Renewables cost is still in free fall. In ten years, renewables will be so cheap that overbuilding 10x, 20x, will be cheaper than operating a nuke.

Ok, we replaced a coal plant with solar panels. What do we do at night? Build storage for the solar plant? That's more expensive than a nuclear plant of the same capacity. Build long range high voltage power lines? Again, more expensive than building a nuclear power plant of the same capacity. People have been spoiled by the incredible energy ROI, portability and responsiveness of fossil fuels and think everything ha…

Storage is cheap and getting cheaper even faster than solar or wind.

By the time we need storage (after enough renewable generation is built to charge it from) storage will be very cheap. It will not be made of lithium batteries.

Re: More invested in nuclear fusion in last 12 months than past decade

#493

Post by feet » Sun, Jul 24, 2022, 11:23 AM UTC

CTDOCodebases wrote: post #490

feet wrote: post #485

Earlier quoted context omitted.

The consequences from pushing more carbon out are worse than one nuclear plant failure

So are you saying that only one plant will fail out of the many we need to build and that our only option is to continue using hydrocarbons for energy? I'm tempted to be hopeful and say that nuclear will solve all our problems but seeing how the energy industry got us here in the first place I'm sceptical they have our best interests at heart.

By energy industry do you mean oil and gas? Are they the ones building nuclear plants?

Engineering improves over time, considering we seem to have someone who works in the industry in this thread perhaps they can inform us about current failure rates and risks. My assumption is that due to past failures, extra mitigations have been put into place with modern reactors.

Re: More invested in nuclear fusion in last 12 months than past decade

#494

Post by Schroedingersat » Sun, Jul 24, 2022, 11:24 AM UTC

belorn wrote: post #444

bakuninsbart wrote: post #428

Earlier quoted context omitted.

You can however price this in, and I doubt it accounts for 110$/MW. Furthermore, nuclear energy specifically only runs according to schedule. Reducing or raising output is expensive and slow.

For simplicity, lets use the cost of for every $ that a KG of green hydrogen costs, this mean that the cost per MW will be 30x of that. So if green hydrogen cost $1/KG you the cost in term of MW will be $30. The current cost of green hydrogen is somewhere between $2 -> $12. That is the production cost. The market price for green hydrogen sits around $4-$20, since there are multiple industries that demands hydrogen. F…

Why would opex and amortised capital scale with fuel price?

Re: More invested in nuclear fusion in last 12 months than past decade

#495

Post by tuatoru » Sun, Jul 24, 2022, 11:25 AM UTC

ascar wrote: post #451

cycomanic wrote: post #416

Earlier quoted context omitted.

Just repeating the baseline myth does not make it true. Nuclear does not compete with gas it competes with coal and renewables. It is often technically difficult but more importantly economically prohibitive to run nuclear as on demand sources. So for both renewables and nuclear you need some sort of storage or peakers. Moreover nuclear is not the beacon of reliability, Frances nuclear plants were running to only 60%…

> So for both renewables and nuclear you need some sort of storage or peakers. One thing I don't understand here is the problem with overproduction. If we actually have excess electricity (as in not needed as electricity later) can't we dynamically use that for active carbon capturing? The efficiency of that process isn't even that important then as the main goal is to remove carbon from the atmosphere with carbon fr…

See Casey Handmer[1]. We are underproducing solar PV by at least 4.8 TW (nameplate) per year: we're only producing about 4% of what we need.

There is no such thing as overproduction, there are only manufacturing bottlenecks in batteries, electrolyzers, and reverse osmosis water plants.

1. https://caseyhandmer.wordpress.com/2022/07/22/were-going-to-...

Re: More invested in nuclear fusion in last 12 months than past decade

#496

Post by nixass » Sun, Jul 24, 2022, 11:27 AM UTC

dignick wrote: post #381

acidburnNSA wrote: post #153

But where are the fusion neutrons? (See Voodoo Fusion [1]) [1] https://vixra.org/pdf/1812.0382v1.pdf I'm a professional fission guy. I started out in fusion and switched to advanced fission. These days I don't see why we don't just build lots more regular old LWR fission reactors. Imagining that somehow fusion is going to a) work, b) be cheap (fuel cost is only 5% of total nuclear fission cost so who cares), and c) n…

There are several problems with fission (probably fusion too) as I understand it: 1. Cost per MW compared to renewables (~$150 vs ~$40 and falling). Here in the UK the government is promising to subsidise this to make it viable. 2. Construction time - average is 10 years, we don’t have that long to wait. 3. Decommissioning is expensive and a long way in the future. Is that cost built into the cost per MW? How can we…

> 2. Construction time - average is 10 years, we don’t have that long to wait

You've been saying that for last 20 years. It's pathetic by this point. Best time to start doing things (anything) was 30 years ago. Second best time is now

Re: More invested in nuclear fusion in last 12 months than past decade

#497

Post by pfdietz » Sun, Jul 24, 2022, 11:30 AM UTC

adgjlsfhk1 wrote: post #358

acidburnNSA wrote: post #341

Earlier quoted context omitted.

For seawater extraction, you just put enough uranium capture fibers in a few places and the uranium is delivered to you slowly over billions of years via ocean currents. This is well supported by the various articles and entire scientific issue featured in the See Also section. But if you don't buy seawater extraction, check out the Weinberg 1959 reference ( https://doi.org/10.1063/1.3060564 ), which contains a calcu…

this has some serious problems in the analysis. First of all, about half of the earth's crust is under an ocean. Second, of the remaining half, it is on average about 10 miles deep. There is no way that digging up 10 miles of rock to get to some scattered uranium atoms is net positive from an energy perspective. The deepest mines in the world are 2.5 miles under ground, and is in a location with a very high concentra…

Ocean floor bedrock is basalt, which has much lower U/Th content than granite. Granites are continental rocks.

Geologically, U and Th have been concentrated over the billions of years by about a factor of 1000 in the minerals that have accumulated in continents. Were this not the case, fission power would be completely impractical.

Re: More invested in nuclear fusion in last 12 months than past decade

#498

Post by thrown_22 » Sun, Jul 24, 2022, 11:34 AM UTC

ncmncm wrote: post #492

thrown_22 wrote: post #480

Earlier quoted context omitted.

Ok, we replaced a coal plant with solar panels. What do we do at night? Build storage for the solar plant? That's more expensive than a nuclear plant of the same capacity. Build long range high voltage power lines? Again, more expensive than building a nuclear power plant of the same capacity. People have been spoiled by the incredible energy ROI, portability and responsiveness of fossil fuels and think everything ha…

Storage is cheap and getting cheaper even faster than solar or wind. By the time we need storage (after enough renewable generation is built to charge it from) storage will be very cheap. It will not be made of lithium batteries.

By the time storage is ready we won't need electricity because climate change will have made industrial civilization impossible.

Re: More invested in nuclear fusion in last 12 months than past decade

#499

Post by tuatoru » Sun, Jul 24, 2022, 11:36 AM UTC

Galaxeblaffer wrote: post #463

ncmncm wrote: post #436

Earlier quoted context omitted.

Building 3x renewables in widely distributed places radically reduces volatility. Wind is always blowing somewhere. Sun is always out somewhere. Storage is transportable.

Is storage really transportable ? Like how much energy in any form could you realistically transport for any meaningful distance without using too much of the energy that you are transporting ? Since you made the claim I'd like you to paint any kind of realistic scenario.

Hydrocarbons, especially medium-chain liquid hydrocarbons, can easily and safely be transported 10_000 kilometres and further.

Doing exactly that is presently about a quarter of total global international trade by value.

Their advantages of high energy density, safety, and undemanding environmental and handling requirements (distribution can be performed in temperatures from -40 to +40 celsius by almost untrained teenagers), and effectively unlimited storage duration and volume, far outweigh the energy inefficiency of producing them from atmospheric carbon. Especially once PV gets cheap enough.

Edit: I notice I didn't answer your question. For liquid hydrocarbons, I believe the answer is in the single digit percents, perhaps five percent. For LNG, the energy cost is much higher, perhaps as much as a third of the total energy value.

Re: More invested in nuclear fusion in last 12 months than past decade

#500

Post by pfdietz » Sun, Jul 24, 2022, 11:39 AM UTC

adrian_b wrote: post #434

mlindner wrote: post #377

Earlier quoted context omitted.

> No proliferation risk at all in a tritium fountain full of 14 MeV neutrons? Are you sure you know what you're talking about? If you're putting hunks of uranium inside a fusion pressure vessel it'd be really obvious. Tritium itself doesn't have proliferation risk. > These will all be guarded with pseudo military guns guards and gates just like fission, and monitored by the IAEA. No they won't. Because even if you cr…

It is completely premature to claim that the radioactivity will be "several orders of magnitude less". The neutron flux produced by a fusion reactor will be much higher than in any fission reactor, and it must be absorbed in a shield, to produce heat, which will be the output of the fission reactor. Choosing an appropriate material for the shield will minimize the quantity of radioactive material that is created per…

DT fusion reactors can produce much less radioactivity, particularly long lived radioactivity, than fission reactors, but there are some caveats.

First, the radioactivity is spread through a much larger volume of material. The cost of dealing with it will have a component related to the volume rather than the total radioactivity. It's not clear that dealing with fusion's waste problem will be cheaper than dealing with fission's.

Second, getting low induced radioactivity, and particularly low production of radioisotopes with long half lives, may require expensively low concentrations of impurities in the reactor materials. For example, the RAFM steel Eurofer 97, a top candidate for a DT reactor construction, contains a small amount of nitrogen. Even this trace caused problems from 14C production pushing the steel over a regulatory limit requiring the steel to be disposed of more expensively due to that 14C content.

(I also have seen a claim from Abdou that the Eurofer 97 for DEMO would cost $3B, just for the raw steel. I'm not clear where this estimate comes from but it could be due to the need to expensively purify the steel of impurities to avoid their activation.)