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

#581

Post by dmitriid » Sun, Jul 24, 2022, 4:09 PM 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 we need storage

We already need it. During summer we have an overabundance of energy. It would be so nice to have it stored and used in winter, wouldn't it?

Oh wait. "Cheap storage" in no way, shape or form translate into efficient storage. You might have to cover half of Europe in batteries to store just a few weeks worth of energy.

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

#582

Post by lven » Sun, Jul 24, 2022, 4:12 PM UTC

mlindner wrote: post #353

dongobongo wrote: post #330

Earlier quoted context omitted.

Meltdown accident: basically, reactor is turned off, however heat continues to be generated because of a thing called decay heat which is when isotopes generated by the fission reactions decay to more stable isotopes and release energy. It's about 7% of a fission reactor's power and continues for a few hours until it's negligible. 7% of a gigawatt reactor is like having a couple of jet engines going full blast inside…

> I read recently that fusion reactor will also generate decay heat from all the activated components and this is comparable to a fission reactor. I'd like to know where you read that as the entire idea is to build a reactor out of things that don't activate or are very hard to activate. i.e. things that thermalize or reflect neutrons. Fission reactors produce tons of neutrons too (they kind of have to to work more s…

I think they are talking about me.

Here's two papers about decay heat in ITER: https://www.sciencedirect.com/science/article/abs/pii/092037..., and https://www.sciencedirect.com/science/article/pii/S092037961...

I used their data to find power density and compared it the micro modular fission (MMR) fission reactors.

“MMR has a lower decay heat power density than fusion systems like SPARC or ARC, DEMO, or ITER and orders of magnitude lower than other advanced fission reactors as show in the figure below. UNSC's MMR has the lowest decay heat power density at 0.075 W/cm3, less than DEMO's 0.083 W/cm3 in the blanket and divertor. A lower decay heat is more manageable by passive cooling systems, allowing the reactor to dissipate heat more easily and without damaging the reactor. The other aspect to consider is the maximum temperatures that can be safely maintained in the reactor. Gas-cooled reactors like the MMR have all-ceramic cores that can withstand much higher temperatures than a fusion's reactors metals, molten salts, and magnets. MMR's low power density is a paradigm shift in nuclear safety, more foundational than fusion, for it can be accomplished cost effectively today.”

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

#583

Post by lven » Sun, Jul 24, 2022, 4:13 PM UTC

lawrenceyan wrote: post #342

dongobongo wrote: post #330

Earlier quoted context omitted.

Meltdown accident: basically, reactor is turned off, however heat continues to be generated because of a thing called decay heat which is when isotopes generated by the fission reactions decay to more stable isotopes and release energy. It's about 7% of a fission reactor's power and continues for a few hours until it's negligible. 7% of a gigawatt reactor is like having a couple of jet engines going full blast inside…

If there's truly no meltdown risk with micro reactors, I'm all for it. In terms of fusion, I'd much rather make the tradeoff of increased cost in order to remove issues of vulnerability completely. I want to be able to not even have to think about / plan for dealing with a meltdown scenario.

This is it: https://usnc.com/mmr/

I work on it.

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

#584

Post by dmitriid » Sun, Jul 24, 2022, 4:19 PM UTC

sweezyjeezy wrote: post #211

dmead wrote: post #207

Earlier quoted context omitted.

Is it wise to write off safety issues? Chernobyl, Fukushima and three mile island all seem pretty bad. There is also the Robert Heinlein story "Blowups happen". I'm just not understanding how this can all be hand waved away.

Also hand waving away the fact that the waste products have to be managed for civilisation-length time scales.

The total amount of waste fuel produced by all of humanity since nuclear power became a thing is magnitudes less than the waste produced by solar panels and wind turbines that will need to be decommissioned due to age (some of them already in the near future)

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

#585

Post by seanmcdirmid » Sun, Jul 24, 2022, 4:20 PM UTC

ksaxena wrote: post #65

seanmcdirmid wrote: post #58

Earlier quoted context omitted.

Solar is basically indirect fusion.

Well, with that logic, coal is also indirect fusion

Solar is less indirect than they. It’s like if we made our own fusion reactor and rather than using it to boil water close by to generate steam, we put the water a few miles out.

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

#586

Post by indymike » Sun, Jul 24, 2022, 4:21 PM UTC

ncmncm wrote: post #484

upwardbound wrote: post #447

Earlier quoted context omitted.

I think you're being pretty quick to write off a subject matter expert on a topic that is their own field of expertise.

Their field involved exactly zero need for economic analysis. Naval reactor "engineering laboratory technicians" (SMAGs) are reputed among submariners as habitual liars. Strange but true.

> Their field involved exactly zero need for economic analysis.

This is just dismissing the argument without addressing the assertion that the vast majority of cost in building nuclear is imposed by overly burdensome regulation.

> Naval reactor "engineering laboratory technicians" (SMAGs) are reputed among submariners as habitual liars.

From personal experience, ELTs were held to the exact same zero tolerance for lies standard I was. If you were caught by anyone lying you were out. Rank didn't even mater, nor did it matter if they were nukes or not. If you lied and it was caught, nuclear career over. I watched many people end their careers over how many push-ups they completed in a fitness test, covering for a buddy who was out with a girl when they shouldn't have been, lying about getting a tattoo, or even lying about what they ate for lunch. It was absolutely brutal.

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

#587

Post by belorn » Sun, Jul 24, 2022, 5:30 PM UTC

Schroedingersat wrote: post #494

belorn wrote: post #444

Earlier quoted context omitted.

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?

The report is likely this one: https://www.oecd-nea.org/upload/docs/application/pdf/2019-12...

The $147 figure is basically the worst case scenario.

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

#588

Post by logifail » Sun, Jul 24, 2022, 5:39 PM UTC

dmitriid wrote: post #567

logifail wrote: post #538

Earlier quoted context omitted.

The problem isn't really to what extent nuclear is load-following, but that the economics of nuclear look even worse than they already do if we want to follow the cheapest generator. To be blunt: if the sun is shining and it's windy, no-one really wants to buy a nuclear plant's output. Not at an agreed fixed price, or possibly at any price. The idea of nuclear getting paid the same price - or worse, an index-linked p…

> if we want to follow the cheapest generator. Energy isn't just about generation > If nuclear is as necessary, competitive and flexible as some make out, then go right ahead and build your plant(s). Just don't expect taxpayers to underwrite anything. By the same logic taxpayers shouldn't underwrite any renewables: they are significantly slower than nuclear, and have literally zero base load capacity.

> By the same logic taxpayers shouldn't underwrite any renewables: they are significantly slower than nuclear, and have literally zero base load capacity.

The cost for offshore wind projects has fallen so fast in the UK that the many of the latest projects don't need subsidies, see this report from Imperial College (London)[0], in fact they'll be paying the government, see this article from Bloomberg.[1]

I'm pretty sceptical about the phrase 'base load', when it comes up, such as in a HN discussion[2] from a last week, it seems to be used to describe wanting to choose slow and/or expensive power plants.

EDIT: See also this[3] recent HN discussion, in which it was pointed out "California has put emphasis on renewables and if the nuclear power station isn't guaranteed to provide base load then it's too expensive to operate"

[0] https://www.imperial.ac.uk/news/200353/offshore-wind-power-c... [1] https://www.bloomberg.com/news/articles/2022-01-13/high-powe... [2] https://news.ycombinator.com/item?id=32152588 [3] https://news.ycombinator.com/item?id=31610996

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

#589

Post by CamperBob2 » Sun, Jul 24, 2022, 5:47 PM UTC

serf wrote: post #208

CamperBob2 wrote: post #152

Earlier quoted context omitted.

Sigh, this again. Induced demand is still valid economic demand, and congested roads are still being used productively. There's a reason why sane governments don't regularly "improve" roads by removing lanes.

> Sigh, this again. has this kind of initial dismissal ever won anyone any favor in an argument? I see it all over the thread, and I find myself having a hard time wanting to consider the argument afterwards even if I am personally aligned with them just because it seems so inconsiderate and rude. Is it supposed to signal your experience in the field, having heard this argument so many times -- or does it signal the…

Agreed, it was a low-effort rebuttal to a low-effort post, and I feel bad for contributing to the noise floor on here by taking the bait.

The admins make it clear that neither behavior is wanted, but the argument in question really gets my goat. In my area, road diets and similar ways to deny demand for increased capacity aren't just fallacious arguments, but key elements of public policy that are seemingly engineered to waste time and fuel while contributing to pollution. The only time such arguments are valid are when they've already been applied farther downstream, where the next bottleneck is inevitably cited as a reason why expanding capacity in a given area "won't work."

Similar policies could be applied in many other places, yielding outcomes that pretty much everyone would agree are worse than the status quo, yet for some reason they always find a receptive audience when the problem domain is transportation.

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

#590

Post by downrightmike » Sun, Jul 24, 2022, 6:04 PM UTC

thrown_22 wrote: post #374

downrightmike wrote: post #253

Earlier quoted context omitted.

The problem is energy companies and the entrenched family assholes that run them. Three Mile Island was being forced to push ahead and use the crane to move the vessel, even though it WAS damaged and would have likely lead to a meltdown. Engineers knew it wasn't safe and were punished and fired for not using the crane unless it was actually checked and in working order. The public is right to be wary of nuclear when…

And how is it better when those assholes kill tens of thousands with coal every year instead? If we lynched a few of them every time a nuclear reactor blew up we'd have a lot fewer energy related deaths and the market would eventually self correct.

Assholes are just that. But the issue is that if nuclear fucks up, that land is useless, and since those assholes run it, it has a high likely hood of happening. Half life of plutonium is 24k years, so it is much worse than coal, because it will kill for generations and last far longer. IE _everything_ in that area DIES for hundreds of thousands of years.