US Department of Energy: Fusion Ignition Achieved • Hacker News Board

Re: US Department of Energy: Fusion Ignition Achieved

#991

Post by rbanffy » Thu, Dec 15, 2022, 5:14 PM UTC

eru wrote: post #980

rbanffy wrote: post #903

Earlier quoted context omitted.

> Maybe not on earth, but there are applications in deep space. Depends on how long the interstellar craft is supposed to travel. If it's under 100 years, fission should be able to do the trick of keeping the craft warm and the lights on for the sealed ecosystem to function during the decades of coasting between stars. Fusion rockets would be more convenient than fission ones because you can store the hydrogen you ne…

> Depends on how long the interstellar craft is supposed to travel. I didn't have (only) travel in mind. I was thinking of living between the stars.

You'll need a constant power supply for the entirety of the trip. After doing the math, it turns out, fission seems quite viable - all usual fuels, in storage, have half-lives of more than 10,000 years.

So, if you have enough fissiles for keeping the closed ecosystem happy for the duration of the flight, you can go quite far.

The ship/colony will need to enter orbit around a star and drop by a rocky planet at some point, to gather more fissiles and reaction mass (and other materials needed for fixes and upgrades), so it wouldn't be able to stay indefinitely in deep space. If it's fusion-driven, a gas giant may be a good option for both fuel and reaction mass, and icy moons may work well for replacing water.

Re: US Department of Energy: Fusion Ignition Achieved

#992

Post by LarryMullins » Thu, Dec 15, 2022, 6:50 PM UTC

ncfausti wrote: post #677

LarryMullins wrote: post #548

Earlier quoted context omitted.

That's just the lasers, the rest of the plant needs power too. Big water pumps are big power hogs, as is the rest of the supporting equipment that any power plant requires to operate. Far over "wall plug" break even is required for commercial viability.

Just bootstrap a second fusion power plant with the first, then continue on, similar to how compilers for a language can be written in the language itself.

Bootstrapping the power plant isn't the problem. The economics of the power plant are the problem, naming producing a worthwhile surplus of power, after accounting for all the power needed by the plant itself.

Re: US Department of Energy: Fusion Ignition Achieved

#993

Post by stonogo » Thu, Dec 15, 2022, 6:56 PM UTC

carabiner wrote: post #856

stonogo wrote: post #846

Earlier quoted context omitted.

Yes, that's how research works. What's your point?

The Wrights didn't start from a government-funded initiative. Using govt resources, like public roads or receiving public schooling as a child doesn't make every subsequent output a "government initiative." This is semantics at this point though. You've made up your mind, and so have I, and you're obviously sitting on this thread to rapid fire rebut on this Tuesday night. Here you go, have the last reply:

I didn't say anything about roads or school. The Smithsonian actively executed aviation research by physically building and flying powered aircraft. These experiences were among the information sent to the Wrights. The Wrights' work was directly informed by government experimentation at the Smithsonian. I don't understand how better to communicate this, and I don't understand why you got weirdly personal about it. I hope things get better for you.

Re: US Department of Energy: Fusion Ignition Achieved

#994

Post by rrrrrrrrrrrr2 » Thu, Dec 15, 2022, 9:01 PM UTC

azinman2 wrote: post #986

rrrrrrrrrrrr2 wrote: post #971

Earlier quoted context omitted.

And somehow harnessing the power of the literal sun will have a better safety rate? It's all speculation at this point because fusion doesn't exist yet... but it does seem like a huge undertaking to get superior safety over fission.

It’s not speculation because so much is known about the physics and elements involved. With fusion you want lighter particles which tend to be less radioactive, rather than heavy uranium etc particles for fission. See https://www.iaea.org/bulletin/safety-in-fusion for more details

”Regulatory bodies have vast experience in the realm of safety and security for fission. We are working with them to ensure that all applicable knowledge is transferred to fusion."

Let me put the question another way: suppose we get fusion that's equally as safe as fission like IAEA is saying here. Why would we switch to it if we were unwilling to switch to fission?

Re: US Department of Energy: Fusion Ignition Achieved

#995

Post by throw827474737 » Thu, Dec 15, 2022, 10:07 PM UTC

eru wrote: post #983

throw827474737 wrote: post #873

Earlier quoted context omitted.

That, but also mimicing the pressure of the sun here is just not possible (yet? :D), why we need to play with higher temperaturs with different problematic consequences.

Well, have a look at https://qr.ae/prpVIL which says: > The highest instantaneous pressures we can obtain here on Earth are in the Fusion reactor at the National Ignition Facility and in Thermonuclear weapon detonations. These achieve pressures of 5 x 10^12 and 6.5 x 10^15 Pascal respectively. For comparison, the pressure inside our Sun’s core is 2.5 x 10^16 Pascal.

Okok, amazing! But far from the controlled thing we'd like to have? :D

Re: US Department of Energy: Fusion Ignition Achieved

#996

Post by azinman2 » Thu, Dec 15, 2022, 11:14 PM UTC

rrrrrrrrrrrr2 wrote: post #994

azinman2 wrote: post #986

Earlier quoted context omitted.

It’s not speculation because so much is known about the physics and elements involved. With fusion you want lighter particles which tend to be less radioactive, rather than heavy uranium etc particles for fission. See https://www.iaea.org/bulletin/safety-in-fusion for more details

”Regulatory bodies have vast experience in the realm of safety and security for fission. We are working with them to ensure that all applicable knowledge is transferred to fusion." Let me put the question another way: suppose we get fusion that's equally as safe as fission like IAEA is saying here. Why would we switch to it if we were unwilling to switch to fission?

You’re making false equivalences, and ignoring all of the fundamental differences between the technologies. The materials involved are different, the chain reactions are different, the kinds of radiation and half lives are different, the way you build the cores are different (and are still being worked on for fusion).

The entire reason why people are working on fusion IS the fact that it’s much much safer due to all of the key differences. That doesn’t mean there aren’t lessons from fission to transfer, just as lessons from ICE cars have gone to EVs.

Re: US Department of Energy: Fusion Ignition Achieved

#997

Post by iamgopal » Fri, Dec 16, 2022, 8:27 PM UTC

RobinL wrote: post #945

iamgopal wrote: post #764

Earlier quoted context omitted.

How easy is to write $1T, but with that you can basically install enough solar cell to power all of USA energy need.

Here's some rough numbers, hopefully i haven't made any mistakes: Total US energy generation 2021: 4 trillion kwh Average power generation: 457Gw Cost of Topaz solar farm: $2.5bn Potential output: 550 Mw Cost per Mw $4.5m Spend a trillion on similar capacity, you get 220Gw potential output. But that's assuming you get 550Mw average. In fact, it produces about 1282Gwh output a year, so average is more like 145Mw. So a…

Don’t forget that, 1 trillion can get you lots of leverage and cost benefits In installation and solar panel production. I’ll do it for 1 trillion.

Re: US Department of Energy: Fusion Ignition Achieved

#998

Post by Dagonfly » Fri, Dec 16, 2022, 10:17 PM UTC

RobinL wrote: post #945

iamgopal wrote: post #764

Earlier quoted context omitted.

How easy is to write $1T, but with that you can basically install enough solar cell to power all of USA energy need.

Here's some rough numbers, hopefully i haven't made any mistakes: Total US energy generation 2021: 4 trillion kwh Average power generation: 457Gw Cost of Topaz solar farm: $2.5bn Potential output: 550 Mw Cost per Mw $4.5m Spend a trillion on similar capacity, you get 220Gw potential output. But that's assuming you get 550Mw average. In fact, it produces about 1282Gwh output a year, so average is more like 145Mw. So a…

> Cost per MW: $4.5m

That's quite high. Here in Germany they assume 530-800€ per kW_peak for a utility-scale ground-mounted system (2021) [0]. You can add additional CAPEX for inflation and expansion of the grid, but If you add batteries for night-time balancing, LCOE roughly doubles for now.

Economically, no other energy source will beat non-winter day-time PV in the foreseeable future. Imo, as long as other plants are running during those times, investing in PV is a no-brainer.

[0] https://www.ise.fraunhofer.de/en/publications/studies/cost-o...

Re: US Department of Energy: Fusion Ignition Achieved

#999

Post by ufmace » Fri, Dec 16, 2022, 11:55 PM UTC

shawn-butler wrote: post #853

ufmace wrote: post #586

Earlier quoted context omitted.

"Funding" isn't really a good answer IMO. I don't know a ton about Fusion research specifically, but NASA is horrifically inefficient with money compared to private competitors. Giving them more money won't magically make them more efficient. Reasons why include: - Their incentive is to optimize for political approval, which means spreading facilities among as many congressional districts as possible, which creates a…

>> Their incentive is to optimize for political approval, which means spreading facilities among as many congressional districts as possible, which creates a ton of inefficiency from poor communication Ummm.. I thought remote work was no less efficient?

Remote work is fine in some circumstances. One of the circumstances where it is definitely not fine is in designing, manufacturing, and testing high-precision aerospace hardware. You aren't gonna put a 5-axis CNC mill in your garage.

Re: US Department of Energy: Fusion Ignition Achieved

#1000

Post by eru » Sun, Dec 18, 2022, 7:21 AM UTC

rbanffy wrote: post #991

eru wrote: post #980

Earlier quoted context omitted.

> Depends on how long the interstellar craft is supposed to travel. I didn't have (only) travel in mind. I was thinking of living between the stars.

You'll need a constant power supply for the entirety of the trip. After doing the math, it turns out, fission seems quite viable - all usual fuels, in storage, have half-lives of more than 10,000 years. So, if you have enough fissiles for keeping the closed ecosystem happy for the duration of the flight, you can go quite far. The ship/colony will need to enter orbit around a star and drop by a rocky planet at some po…

I'm not talking about travel. I am talking about permanently living between the stars, and essentially living off hydrogen harvested from the interstellar medium.