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Nuclear fusion milestone passed at US lab

bbc.co.uk

131–140 of 222 posts

Re: Nuclear fusion milestone passed at US lab

#131
post #23

Wow, I remember seeing this project start up a few years ago, about how they wanted to make a "sun" on Earth. It seems it only took them 5 years to achieve this: http://www.telegraph.co.uk/science/science-news/3981697/Scie... In a way, it reminds of Spiderman, too, but let's hope things don't go as badly as in the movie, once we start to make that "sun" big enough to provide a ton of energy.

This is a trite and meaingless comment.

Spiderman? Really?

Re: Nuclear fusion milestone passed at US lab

#132

What ever happened to the polywell reactor design?

It's all classified. It may be useful as an economical neutron source, or as a way to keep a contractor in business, but there's been nothing published about its efficacy as a reactor for sustained fusion power.

If there's one thing we've learned over the past few years, it's that "classified" knowledge, with no critical eyes to keep it honest, is often wrong. Science works, not because it's done in secret.

Re: Nuclear fusion milestone passed at US lab

#133
post #72
post #68

Earlier quoted context omitted.

The NIF is probably more useful for coming up with new fusion bomb designs than for stockpile stewardship, as you say, but what makes you say hot fusion can never be economically viable? The sun is proof that nature can do this on a grand scale! It may be a long ways off, but "a long ways" becomes "never" without experimental work like the NIF. Yes, the U.S. is probably doing this primarily to create new weapons just…

Whether the sun is capable of fusion isn't super important. We can take advantage of that, but it doesn't mean we can build many safe plants based on an evolution of the NIF design. If your alternative fuel requires hundreds of billions of dollars of investment in the future, just to show viability of the basic research concept, before it can actually be useful, you will be at a massive competitive advantage relative…

> What I am saying, is that relative to other potential investments, fusion does not seem to be a worthwhile investment, as the risk/payoff ratio is worse.

I disagree. There exists MILLIONS of years worth of fuel on earth, compared to a few decades of oil and gas, and a few hundred years worth old coal or fissionable uranium. That's quite a huge payoff for relatively little risk (compare fusion research funding with other energy subsidies).

Re: Nuclear fusion milestone passed at US lab

#134
post #47

It is an important milestone. But to have a commercially viable fusion reactor, you'll need a factor of 50-100 more energy out than in to make up for inefficiencies in electricity generation using this kind of scheme. The real story here is that this facility allows the US to do nuclear weapons research without violating the nuclear test ban treaty. If the goal was to develop a commercially viable fusion reactor, the…

I am waiting for the hack of cold fusion;

Now wikipedia says that imploding bubbles create some high energies;

http://en.wikipedia.org/wiki/Mechanism_of_sonoluminescence http://en.wikipedia.org/wiki/Bubble_fusion

Maybe if you shoot up Deuterium bubbles in compressed water and push in some ultrasound waves ....

Re: Nuclear fusion milestone passed at US lab

#135
post #30

tl;dr - Another article about the US nuclear weapons research facility at Lawrence Livermore, AKA NIF, and its sideshow 57th priority. On a related note. It's been really sad to see the US slowly lose its edge in plasma based fusion tech, specifically tokamaks, which seem to be the only credible long-term method of sustaining a fusion reaction for power-plant purposes.

Just a couple quibbles from a former NIF scientist. NIF is much higher on the priority list than that. LLNL is already in the doghouse due to NIF failing to ignite on schedule. As goes the 5 giga-buck NIF, so goes LLNL (and the management knows it). Technologically, I'd put inertial and magnetic fusion about the same place. Even if the physics works, neither has a chamber first wall material that can stand up to the…

Well, fusion could radically decrease the cost of power, which would in turn increase the quantity demanded massively. So 1000MW might be reasonable.

Re: Nuclear fusion milestone passed at US lab

#136

Earlier quoted context omitted.

The BBC did say: > the amount of energy released through the fusion reaction exceeded the amount of energy being absorbed by the fuel As soon as I saw that, I immediately understood that they're nowhere near breakeven -- much less power generation.

It's an extremely misleading half-truth. Worse, Q must be an order of magnitude greater than 1 IIRC to be economically viable.

They did not mention Q at all in the article and their claims cannot be compared to any intellectually honest definition of "break even" in good faith without more information

Re: Nuclear fusion milestone passed at US lab

#137

Earlier quoted context omitted.

Coal power is more deadly than fission power? When has coal power ever created the sort of crisis that occurred in Fukushima? Because of fission reactors, the safety of entire regions of the world is dependent on a consistent power supply and lack of human error, something that clearly we can not rely on. In the event of a cosmic emp or major meteor strike, these power plants are at risk.

Coal power creates that kind of crisis every day, so we don't bother calling it a crisis anymore. A total of 240,000 years of life were said to be lost in Europe in 2010 with 480,000 work days a year and 22,600 "life years" lost in Britain, the fifth most coal-polluted country. http://www.theguardian.com/environment/2013/jun/12/european-...

"commissioned by Greenpeace International" who I'm sure would back the position that nuclear fission plants are safer than coal.

Of course, nuclear power plants are safe short term. Their threat is catastrophe, which given time, is inevitable.

Re: Nuclear fusion milestone passed at US lab

#138

Earlier quoted context omitted.

It's an extremely misleading half-truth. Worse, Q must be an order of magnitude greater than 1 IIRC to be economically viable.

They did not mention Q at all in the article and their claims cannot be compared to any intellectually honest definition of "break even" in good faith without more information

IIRC from a recent HN discussion, ITER has attained Q of 0.65 and NIF is nowhere close to that.

Re: Nuclear fusion milestone passed at US lab

#139
post #95
post #70

Earlier quoted context omitted.

Finally someone that's actually in the fusion field. Could you say whether or not the NIF research represents a practical path towards a fusion based power source? My understanding is that it would at least be capable of capturing some much needed high pressure empirical data necessary for validating theory. On a side note concerning the NIF funding, the US gov will spend huge sums of money studying Nuclear weapons (…

I've worked in ICF for a nearly a decade. I think NIF research is a necessary step to a ICF based power source. If NIF demonstrates ignition, it can be used to validate our physics models of ICF (turbulence, fusion product transport, thermal conduction, etc). These physics questions are shared by all ICF approaches. However, a fusion power plant will use entirely different laser technology [1], and most likely a diff…

[deleted]

Re: Nuclear fusion milestone passed at US lab

#140
post #47

It is an important milestone. But to have a commercially viable fusion reactor, you'll need a factor of 50-100 more energy out than in to make up for inefficiencies in electricity generation using this kind of scheme. The real story here is that this facility allows the US to do nuclear weapons research without violating the nuclear test ban treaty. If the goal was to develop a commercially viable fusion reactor, the…

I wonder, what more do they need in nuclear weapons? Smaller size? Harder detection? Bigger contamination radius?

Somehow, I am sure, if people start a nuclear war, even the WWII's initial nuclear weaponry will be enough to destroy ourselves, knowing how many countries can now chime in with their own.

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