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Major breakthrough on nuclear fusion energy

bbc.co.uk

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Re: Major breakthrough on nuclear fusion energy

#11

Post by varjag »

yaniqt wrote: post #9
spuz wrote: post #6

> The experiments produced 59 megajoules of energy over five seconds (11 megawatts of power). > This is more than double what was achieved in similar tests back in 1997. > It's not a massive energy output - only enough to boil about 60 kettles' worth of water. But the significance is that it validates design choices that have been made for an even bigger fusion reactor now being constructed in France. I thought this…

Is it possible they subtracted the energy required to facilitate the reaction in the first place? So net energy was enough to boil 60 kettles worth of water?

That would be a fusion breakthrough worth mentioning on its own.

Re: Major breakthrough on nuclear fusion energy

#12

Post by [deleted] »

spuz wrote: post #6

> The experiments produced 59 megajoules of energy over five seconds (11 megawatts of power). > This is more than double what was achieved in similar tests back in 1997. > It's not a massive energy output - only enough to boil about 60 kettles' worth of water. But the significance is that it validates design choices that have been made for an even bigger fusion reactor now being constructed in France. I thought this…

[deleted]

Re: Major breakthrough on nuclear fusion energy

#13

Post by unfocussed_mike »

spuz wrote: post #7
unfocussed_mike wrote: post #4

[flagged]

This could be read as an either pro or anti-brexit comment but the fact that it is ambiguous makes it kind of pointless.

If you can read that as a pro-Brexit comment, then the Brexit project succeeded beyond its instigators' wildest dreams.

It's not ambiguous at all. Everything in the UK going on right now -- everything -- has a "some of this is unclear or worse because Brexit has destroyed agreements or because proposed, nearly impossible agreements have not been struck" subplot.

Brexit has set fire to every kind of international complication.

And so here we are with a sucessful fusion lab in the UK, doing the hard work, that is a precursor to a European project that it is really not at all clear we will be able to participate in or benefit from, because crucial parts of the Brexit neo-establishment want the benefits of the agreements without acceding to the legal underpinnings of the agreements.

Re: Major breakthrough on nuclear fusion energy

#14

Post by ourmandave »

spuz wrote: post #6

> The experiments produced 59 megajoules of energy over five seconds (11 megawatts of power). > This is more than double what was achieved in similar tests back in 1997. > It's not a massive energy output - only enough to boil about 60 kettles' worth of water. But the significance is that it validates design choices that have been made for an even bigger fusion reactor now being constructed in France. I thought this…

But the significance is that it validates design choices that have been made for an even bigger fusion reactor now being constructed in France.

They already started construction on a larger one? What if it had invalidated design choices?

Re: Major breakthrough on nuclear fusion energy

#15

Post by bencollier49 »

samwillis wrote: post #10
spuz wrote: post #6

> The experiments produced 59 megajoules of energy over five seconds (11 megawatts of power). > This is more than double what was achieved in similar tests back in 1997. > It's not a massive energy output - only enough to boil about 60 kettles' worth of water. But the significance is that it validates design choices that have been made for an even bigger fusion reactor now being constructed in France. I thought this…

> That means JET could have boiled about 188 kg of water. > only enough to boil about 60 kettles' worth of water Exactly, no one has 3l kettles, but it's the right ballpark. You could also run about 9k kettles for that 5 seconds but not boil them, and if you tried to run 60 kettles consuming all that power for 5 seconds you would have quite the fire...

> no one has 3l kettles

I have! Duckduckgo it.

Re: Major breakthrough on nuclear fusion energy

#16

Post by unfocussed_mike »

ourmandave wrote: post #14
spuz wrote: post #6

> The experiments produced 59 megajoules of energy over five seconds (11 megawatts of power). > This is more than double what was achieved in similar tests back in 1997. > It's not a massive energy output - only enough to boil about 60 kettles' worth of water. But the significance is that it validates design choices that have been made for an even bigger fusion reactor now being constructed in France. I thought this…

But the significance is that it validates design choices that have been made for an even bigger fusion reactor now being constructed in France. They already started construction on a larger one? What if it had invalidated design choices?

> What if it had invalidated design choices?

The government money was already allocated and even the government can't unring that bell!

Re: Major breakthrough on nuclear fusion energy

#17

Post by remus »

ourmandave wrote: post #14
spuz wrote: post #6

> The experiments produced 59 megajoules of energy over five seconds (11 megawatts of power). > This is more than double what was achieved in similar tests back in 1997. > It's not a massive energy output - only enough to boil about 60 kettles' worth of water. But the significance is that it validates design choices that have been made for an even bigger fusion reactor now being constructed in France. I thought this…

But the significance is that it validates design choices that have been made for an even bigger fusion reactor now being constructed in France. They already started construction on a larger one? What if it had invalidated design choices?

Presumably they feel like the major design choices at ITER have already been validated and this experiment validates some more minor design choices.

Re: Major breakthrough on nuclear fusion energy

#19

Post by samwillis »

bencollier49 wrote: post #15
samwillis wrote: post #10

Earlier quoted context omitted.

> That means JET could have boiled about 188 kg of water. > only enough to boil about 60 kettles' worth of water Exactly, no one has 3l kettles, but it's the right ballpark. You could also run about 9k kettles for that 5 seconds but not boil them, and if you tried to run 60 kettles consuming all that power for 5 seconds you would have quite the fire...

> no one has 3l kettles I have! Duckduckgo it.

Yep, just checked mine and its 3l, oops.

Re: Major breakthrough on nuclear fusion energy

#20

Post by ginko »

spuz wrote: post #6

> The experiments produced 59 megajoules of energy over five seconds (11 megawatts of power). > This is more than double what was achieved in similar tests back in 1997. > It's not a massive energy output - only enough to boil about 60 kettles' worth of water. But the significance is that it validates design choices that have been made for an even bigger fusion reactor now being constructed in France. I thought this…

>In fact, it takes 4,184 joules to raise the temperature of 1kg of water by 1 degree. Or 313800 joules to raise 1kg of water by 75 degrees. That means JET could have boiled about 188 kg of water.

This is missing the heat of vaporization[1] needed to actually boil the water though, i.e. to turn 100C liquid water to 100C steam. That's another 2250kJ/kg on top of the 313.8kJ/kg you've mentioned.

It's why steam is such a great carrier of energy for industrial applications.

I guess you could argue that you wouldn't evaporate all water in the kettle, but then you do want a rolling boil. It's probably a bit up for discussion at which point you'd stop heating the kettle.

[1] https://en.wikipedia.org/wiki/Enthalpy_of_vaporization

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