Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Skunk Works Reveals Compact Fusion Reactor Details

aviationweek.com

Post reply on HN
Print view View original

141–150 of 375 posts

Re: Skunk Works Reveals Compact Fusion Reactor Details

#141

Post by jeffreyrogers »

TeMPOraL wrote: post #140
thrownaway2424 wrote: post #134

Earlier quoted context omitted.

This is HN. If the hyperloop was a technological breakthrough, so is this press release.

Hyperloop case doesn't have 50 years of track record of being "just few years from now", and as far as I remember, the design was more-less feasible if only someone would get around to building it. It didn't have such hard problems to be solved as fusion still has.

I think you could make the argument that fusion is more or less feasible if someone would just get around to building it too...

Re: Skunk Works Reveals Compact Fusion Reactor Details

#142

Post by notacoward »

adamzerner wrote: post #87

I don't know much about fusion. It seems that the breakthrough they're talking about is that reactors are ~10x smaller. Why is this a big deal? Square footage is plentiful. I thought the problems are safety and how much energy it could produce.

I think it's less about the size in square feet than the size in dollars (including installation, maintenance, and waste disposal). The pool of people willing to buy a $100M device is small. The pool of people willing to buy a $10M device - even if it's less efficient - is much larger. That makes it a potential revenue source, instead of an eternal revenue sink. Much as fusion doesn't become technically useful until energy output exceeds energy input, it doesn't become economically useful until revenue (for its maker) exceeds cost.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#143

Post by Everhusk »

"The team acknowledges that the project is in its earliest stages, and many key challenges remain before a viable prototype can be built."

No doubt that Skunkworks is world class... but claiming a "breakthrough in fusion energy" before a prototype has even been built is pretty bold of them.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#144

Post by wlesieutre »

TeMPOraL wrote: post #136
wlesieutre wrote: post #121

Earlier quoted context omitted.

While Wiktionary has "A device which uses atomic energy to produce heat" as one definition, other dictionaries all include the ability to regulate/control/sustain a nuclear reaction. I'm inclined to agree with them.

Well, we all understand that a nuclear warhead is technically a reactor but not what we mean in practice when we use that word. The typo in the article was just a bit unfortunate.

It's only technically a reactor if you accept Wiktionary's definition of what a reactor is, instead of any of the "real dictionaries". I'm of a mind that setting off an uncontrolled nuclear reaction doesn't make something a reactor.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#145

Post by alkonaut »

wcoenen wrote: post #57

> 100-megawatt reactor measuring seven feet by 10 feet, which could fit on the back of a large truck A typical thermal power station has an efficiency below 50% for electricity generation, so the plant dissipates at least as much heat as it generates electrical power. I wonder how you could get rid of 100MW of waste heat from a volume small enough to fit on a truck. That's a heat flux of more than a megawatt per squa…

Normal cooling (cooling towers or similar) requires a huge structure to dissipate 100MW. The cooling infrastructure can't fit in a truck. What you can to is transport the plant to somewhere where the environment can help with the cooling, such as where there is a good supply of cold water.

One can imagine these to be simple drop in replacements for existing coal plants with existing cooling infrastructure,which would be a huge environmental win in places where those are still built.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#146

Post by DennisP »

dmfdmf wrote: post #125

25 years ago my nuke professor used to scoff at some of the claims of the fusion researchers. The problem is the high energy neutrons flying out of the reactor will neutron-activate every material within the vicinity. He thought the radioactivity and nuclear waste of a fusion reactor could be worse than a fission reactor. Also he thought that fusion researchers were vastly underestimating the problem of neutron embri…

With D-T fusion you would have more activation of the reactor materials, because D-T produces such high-energy neutrons. What you wouldn't have is transuranics, which make up the bulk of our nuclear waste (and all of the really long-lived stuff), or fission products (the most radioactive stuff, like the cesium and strontium we heard about after Fukushima).

But D-T is only the easiest form of fusion. Next up is D-D, which has much lower-energy neutrons. Helion is working on D-D combined with D-He3, producing only 6% of its energy as neutrons. And several outfits are hoping to manage proton-boron fusion, producing very little neutron radiation.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#147

Post by DubiousPusher »

jeffreyrogers wrote: post #141
TeMPOraL wrote: post #140

Earlier quoted context omitted.

Hyperloop case doesn't have 50 years of track record of being "just few years from now", and as far as I remember, the design was more-less feasible if only someone would get around to building it. It didn't have such hard problems to be solved as fusion still has.

I think you could make the argument that fusion is more or less feasible if someone would just get around to building it too...

I don't believe this is the case. I'm pretty sure there have been "hard" limits so far on what can be achieved. I'm not a physicist, not even close but as I understand it two issues remain. One is that sustaining the fusion reaction has been problematic. I believe the longest sustained reactions have been less than one second. Two is that currently we have to put more energy into creating and sustaining the reaction than it yields. These two things make this categorically different than a challenge like building the hyperloop which as far as I know didn't have any unsolved science or engineering problems.

Again, I could be wrong on my physics but as I understand it, fusion power is still a question of "is it even possible" whereas the hyperloop was more of a question about socioeconomic will.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#148

Post by aruggirello »

javajosh wrote: post #93
wcoenen wrote: post #57

> 100-megawatt reactor measuring seven feet by 10 feet, which could fit on the back of a large truck A typical thermal power station has an efficiency below 50% for electricity generation, so the plant dissipates at least as much heat as it generates electrical power. I wonder how you could get rid of 100MW of waste heat from a volume small enough to fit on a truck. That's a heat flux of more than a megawatt per squa…

That's an excellent point! Perhaps they intend the truck to be sitting at the bottom of a fast moving river. But what gets me is that they are burying the lead. No fusion reactor of any size has reached sustainability...so why is the story here talking about size at all? Small size would be a very nice added bonus; fusion reactors that don't consume more energy than they produce are earth-changing.

> Perhaps they intend the truck to be sitting at the bottom of a fast moving river.

That's exactly what I was thinking. They'd better call the Truck a submarine, though.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#149

Post by zo1 »

cowkingdeluxe wrote: post #53

"McGuire said the company had several patents pending for the work and was looking for partners in academia, industry and among government laboratories to advance the work." I'm guessing this means that they will try and maximize profit rather than maximize cheap and clean energy for the entire world. That is a bit disappointing if true.

"I'm guessing this means that they will try and maximize profit rather than maximize cheap and clean energy for the entire world. That is a bit disappointing if true."

I don't understand what you expect? You want them to give it away for free? After paying very intelligent, expensive engineers decades worth of salaries to create it? You want them to create a fund where people can donate their hard-earned money for this noble goal? I'm sure you could give them a call with that idea, or you could create your own fund, even.

Or you could badger your "government" to fund such a project. Seeing as government is a very good analogy for a bunch of people giving their collective earnings for society-level goals. Let me know how that goes.

Re: Skunk Works Reveals Compact Fusion Reactor Details

#150

Post by aruggirello »

pessimizer wrote: post #74
orkoden wrote: post #33

Earlier quoted context omitted.

If they can manage to build what they envision we will have tanks with with laser weapons.

Autonomous drones with facial recognition and laser weapons, rather.

It's about time for Sarah Connors to show up.
Post reply on HN