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

#631

Post by matkoniecz » Mon, Jul 25, 2022, 9:28 AM UTC

smaudet wrote: post #555

matkoniecz wrote: post #526

Earlier quoted context omitted.

> mechanical earth dams (store energy in potential energy mass, less dangerous than an actual water dam, a lot easier to build) a lot easier to build? This claim seems wrong, given that pumped-storage hydroelectricity is in actual use, when this is purely theoretical. "mechanical earth dams" gives info about water dams - is it existing even as a theoretic design?

https://www.energyvault.com/gravity Its a company with as I understand it proven designs. Besides, the concept is trivial and applicable and replicable by almost anyone. I don't understand why there is so much skepticism around these things...

> Besides, the concept is trivial and applicable and replicable by almost anyone.

Has anyone made one operating at major scale? And comparable to say serious pumped storage? At their page I see only "demonstration unit".

I suspect that either it is not solved, expensive or not trivial. And not replicable or there is nothing to replicate or not worth replicating.

For comparison https://pl.wikipedia.org/wiki/Elektrownia_Por%C4%85bka-%C5%B... can operate at 500MW for 4 hours, was build in 1979 and is a normal pumped storage battery (large enough to be classified, operated and treated as a power plant).

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

#632

Post by matkoniecz » Mon, Jul 25, 2022, 9:31 AM UTC

smaudet wrote: post #562

matkoniecz wrote: post #525

Earlier quoted context omitted.

If you use unexpected definition of "exposed" then it would be better to mention it directly... Yeah, obviously direct exposure to core kills. In the same way being pulled through hydropower turbine kills, and ending in furnace of gas/coal/wood heated power plant will kill you. Nuclear power still has vastly lower death ratio per produced energy than other ways generating power anyway. > I am not wrong, in a world do…

Perhaps I am wrong to the degree of which we are doomed in various scenarios, but I am not wrong that serious effects would occur. My concern is - catastrophic chaining failure of nuclear plants, which I must assume you would not think would be a good thing, and would cause 'grave public harm', better? Not arguing over exactly how flesh melted the general populous is. If you remove "instantly fry us all to molten pul…

I am primarily complaining about claim that everyone could die.

That would not happen even in an outright full scale nuclear war.

Exact way of dying (starvation, frying, flash frying, whatever) is not so important to me.

> catastrophic chaining failure of nuclear plants

That is also not going to happen. Even misdesigned soviet atomic bomb factory operating in insanely unsafe mode by incompetents managed to avoid this.

> Nobody but the most crazy out-of-touch pro-nuclear person is going to try to claim that we can directly control neutrons, free particles, or the half lives of deadly carcinogens, or that we can filter them from our water supplies.

The same applies to flood from collapsed dam or emitted CO2 or radiation emitted by coal power plants.

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

#633

Post by nl » Mon, Jul 25, 2022, 9:50 AM UTC

smaudet wrote: post #622

nl wrote: post #610

Earlier quoted context omitted.

> is that a very appreciable fraction of the energy liberated goes into radiant heat and light That's exactly what I said in my previous comment: For example nuclear bombs melting flesh is because of the extreme heat, nothing that is unique to the nuclear process. You see exactly the same "flash burn" characteristics from other very hot weapons eg thermobaric explosives. The unique thing about nuclear bombs is their…

Heat is not light, that is not exactly what you said. Sorry. You didn't even mention light. Physically as well as "mechanically", I suppose, they are very different things. Heat cannot travel at the speed of light, light can. Light can impart heat, but it is a partical-wave with various properties, heat is a general statistical statement about a set of particalls. They are not the same thing at all. Now, as for how a…

Heat and light are exactly the same thing.

Heat is just longer wavelength electro magnetic radiation than visible light.

UV is shorter wavelength EM radiation, so same thing (not quite sure why we are talking about sunburn though).

It outputs a bunch of other EM radiation too. That's what an EMP explosion is - one desiged to maximize EM radiation in frequencies likely to destroy electronic equipment.

I sort of assumed people on HN knew this.

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

#634

Post by Schroedingersat » Mon, Jul 25, 2022, 10:25 AM UTC

neilwilson wrote: post #626

Schroedingersat wrote: post #602

Earlier quoted context omitted.

That is the admitted cost of Hinkley C and lower bound on the cost of Sizewell (it will go up, they always do). Sizewell is a rolls royce smr. Matching end user retail cost of solar. Right now. By the time sizewell comes online it'll be a fraction. It's also calculated with a 12.5% capacity factor which is winter in the UK. Add in overnight costs and it's extremely one sided. You could add as much net capacity as the…

"If there are trillions in the pot" There are always trillions in the pot, because the UK is a sovereign country with its own currency. Money is never the issue. Therefore it's only overnight costs that matter in a build (and hitting the deadline). The real issue is one of manpower and stuff. We don't make solar panels in the UK. We will make SMRs. Therefore we're not reliant on Chinese manufacture, or the whims of e…

Commenting about fiat currency is a pointless distraction when the purpose of using it is as a proxy for labour and materials. 'Trillions in the pot' is just a proxy for a certain amount of access to raw materials, trading ability and labour power, all of which are finite and don't really increase if you sink your country into hyperinflation.

> Therefore it's only overnight costs that matter in a build (and hitting the deadline). The real issue is one of manpower and stuff. We don't make solar panels in the UK. We will make SMRs. Therefore we're not reliant on Chinese manufacture, or the whims of export markets to fund them. A problem we're currently having with gas and oil.

> To have security of energy supply over time you have to be as decoupled from world markets as possible. We don't want to be in the situation where we're relying on China for replacement advanced manufactures to keep the lights on.

Spending an amount on computers and steel and exotic alloys and uranium ore and then also spending 10x as much on labour is no better than spending that first amount on foreign solar panels. Far better to overpay for solar panels by developing a local industry, or overpay for solar thermal systems (which are still vastly cheaper than fission).

> Solar has no reliable capacity in winter in the UK unfortunately. You wouldn't want to rely on solar with several weeks of grey miserable UK winter weather even with storage. The same with wind, which is still suffering from a degradation in capacity due to the as yet unexplained overall reduction in wind speeds - which may itself be a result of climate change.

Renewable-derived hydrogen is already at cost-parity with fossil-fuel-methane derived hydrogen in some markets. Renewable-derived methane isn't much further off and is one of many ways of solving the storage issue. When a gas plant (which you need anyway) and the renewables to provide enough net power in winter and a massive overprovision during summer cost a fraction of nuclear there's no point.

Plus your argument about energy security completely precludes nuclear as an option for over 50% of the world as they're not allowed to make their own fuel. There are also about as many countries with a credible manufacturing base for solar panels than countries with viable uranium reserves, and there is more than one chemistry that you can make solar cells with.

Finally being entirely beholden to one of four or five corporations worldwide is no better than being entirely beholden to one of four or five countries with the cheapest solar.

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

#635

Post by einpoklum » Mon, Jul 25, 2022, 10:36 AM UTC

tptacek wrote: post #616

einpoklum wrote: post #613

Earlier quoted context omitted.

Probability of accident * Expected damage of accident = Expected damage of activity/project. Nuclear has had non-negligible probability of accidents, including dangerous accidents. The expected damage of the dangerous accidents is millions dead and injured, and potential destruction of very wide ecosystems. An accident in a coal power plant mean a bunch of coal burning. Which is bad, but several orders of magnitude l…

At what point do we observe no accident causing millions of deaths or injuries and adjust our "expected damage" calculation? Decades? Centuries? We can look past the damage caused by an accident at a coal plant and just count the damage caused by ordinary routine operation of coal plants and quickly reach damage figures that eclipse every nuclear accident in history combined.

> At what point etc.

Your second paragraph suggests that we are not at that point yet.

But to be less facetious - after the regulatory systems in the relevant country reach a state of high trustworthiness and no indications of 'capture' + a few decades' buffer for the trustworthy regulation's effect to permeate.

And this is ignoring the question of chances of damage by war and the issue of waste management, so maximum over the minimum period for each of these 3 considerations.

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

#636

Post by pydry » Mon, Jul 25, 2022, 11:04 AM UTC

jillesvangurp wrote: post #383

dreamcompiler wrote: post #76

There's a huge amount of hype in fusion these days. Companies are getting big investments just by saying "we're over unity." None of their investors will recoup any money. Getting above unity is important but it's still a very long way from systemic over unity of the entire lifecycle of the process that turns fusion into electricity on the grid. And that simply won't happen in my lifetime or most of your lifetimes. W…

I think investments are happening because recent progress in this space is indicating that this might in fact happen in the next decade or so. The cliche that fusion reactors are perpetually 30 years away, might have actually been correct up to about 20 years ago. There are no guarantees here of course, but there are now quite a few companies acting like they are going to get their first test plants up and running in…

The "30 years away" thing assumed investment.

It's quite weird to think that seeing a potentially endless source of free energy we wouldnt be throwing a trillion dollars or so at it but thats humanity for you.

Scientists were similarly optimistic about space exploration after landing on moon shortly before NASA's budget dwindled.

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

#637

Post by pfdietz » Mon, Jul 25, 2022, 11:19 AM UTC

manholio wrote: post #630

pfdietz wrote: post #513

Earlier quoted context omitted.

Fusion reactors (after they're big enough to have ignited) have diseconomy of scale, due to the square-cube law. Cost scales (at least) as reactor volume, while power is limited by power/area through the surface of the reactor vessel.

But are we hitting that power density ceiling yet? It doesn't seem so, we're not even in the "big enough to have ignited" range, only scraping at the door of "big enough for scientific break-even", but have already blown any reasonable chance for such designs to be cost effective even if they were to be mass produced. Massive superconducting magnets generating megatons of force, building-sized vacuum chambers that ar…

It's not clear there's ANY window for DT reactors between "too small to ignite" and "too large to have competitive volumetric power density".

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

#638

Post by ciphol » Mon, Jul 25, 2022, 11:21 AM UTC

cycomanic wrote: post #418

jamesrom wrote: post #407

Earlier quoted context omitted.

> Construction time - average is 10 years, we don’t have that long to wait. This is a fallacy in two ways: 1. Scaling up nuclear projects will decrease construction time and cost. Efficiencies are found by with scale. 2. The opportunity cost of not starting nuclear projects now will surely be worse than attempting 100% renewables. The point is that we can invest in both.

> > Construction time - average is 10 years, we don’t have that long to wait. > This is a fallacy in two ways: > 1. Scaling up nuclear projects will decrease construction time and cost. Efficiencies are found by with scale. More than half of a nuclear plant is essentially the same as any large scale power plant (goal, gas...). The opportunity for reducing cost through economies of scales is low. Economies of scales w…

> More than half of a nuclear plant is essentially the same as any large scale power plant (goal, gas...).

Presumably that's the cheap half of the nuclear plant, because coal/gas plants are pretty cheap to build.

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

#639

Post by cyanydeez » Mon, Jul 25, 2022, 11:32 AM UTC

danaris wrote: post #199

cyanydeez wrote: post #196

Earlier quoted context omitted.

>After decades of cooling, France, like most other nuclear power generating countries, has no long-term solution in place for high and intermediate spent fuel waste disposal. https://www.power-technology.com/analysis/managing-nuclear-w... Yes, short term they manage it. When we are discussing the future, our concern is long term.

When we are discussing climate change, our concern is not long term. If we could build the nuclear reactors now , keep the spent fuel (whether or not we're going to reuse it in breeder reactors) as safe as we know how, and solve the long-term problem later, then we'd have a much better chance of there being a later to worry about.

Climate change is both.

People proposing nuclear energy as this wonderful overlooked strategy are not consider why it's consistently self limiting.

It's not a "solved" problem inthe long term

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

#640

Post by pfdietz » Mon, Jul 25, 2022, 11:44 AM UTC

ncmncm wrote: post #479

freemint wrote: post #417

Earlier quoted context omitted.

What accident do you foresee that makes components of a fusion reactor sufficiently radio active? Containment field failure should leave the components just as radio active as a controlled shutdown as the plasma distinguishes immediately or am i missing something?

Everything in the reactor is blasted with enormous neutron flux, inducing radioactivity in everything. A thousand tons of molten, radioactive lithium could easily ruin your day, if ever exposed to air.

I don't see how the lithium itself becomes radioactive. It will be contaminated with tritium, but presumably it's designed so that can be stripped out. Otherwise... maybe atoms of higher Z elements knocked into the lithium from the first micro of pipe surfaces by recoil after neutron collisions?