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Nuclear fusion has encountered a shortage of tritium

wired.co.uk

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Re: Nuclear fusion has encountered a shortage of tritium

#31

Post by Enginerrrd »

fffobar wrote: post #14
areoform wrote: post #12

Just a quick reminder, we already have practical fusion with tens of thousands of years of runway available to us today. We choose not to do it because it sounds dangerous and it’s not politically expedient. For those unfamiliar, I am talking about Project PACER. The fusion reactor proposed by Teller after the creation of the thermonuclear weapon. It may sound fanciful but it’s based on a simple precept. We can alrea…

Isn't the problem that the fuse for a fusion bomb is a fission bomb, and a fission bomb very violently disperses lots of radioactive material? What am I not getting?

You control the detonation with either an engineered or natural cavity filled with fluid. You can then use the fluid as a big thermal reservoir to run steam turbines. Per wikipedia:

>"Dropping about two bombs a day would cause the system to reach thermal equilibrium, allowing the continual extraction of about 2 GW of electrical power."

Now... the part you're not getting is that if you can do all that, you can almost certainly just use conventional fission power generation, which is what we really, REALLY need to be doing anyway.

Re: Nuclear fusion has encountered a shortage of tritium

#32

Post by areoform »

cogman10 wrote: post #25
jandrese wrote: post #23

Earlier quoted context omitted.

Some of the heartburn about PACER is that there are failure modes that can only be described as catastrophic.

No shit. Turns out a daily detonation of a fusion bomb tends to wear on things and when those things fail... you've just detonated a fusion bomb.

We’re facing a catastrophe. I and others have described elsewhere that the path we’re on is much, much worse than even the most dire of predictions the IPCC makes. https://news.ycombinator.com/item?id=30947756

Teller et al anticipated your objection. It’s why the reactor is supposed to dig into sold rock. If there’s a catastrophic failure then it’s yet another subsurface nuclear test. And the more advanced designs considered for Project Plowshare produce minimal residual radioactivity. All of the products dissipate within 6 months.

So, in the worst case scenario, the facility gets buried under tons of rocks, far away from any water. And the residual radioactive products rapidly decay into being harmless with 6 months. Any induced radioactivity from the neutrons produced during the explosion will follow a fairly predictable pattern as well.

This can be done.

In exchange we get a reactor that creates nearly limitless power for entire countries.

Re: Nuclear fusion has encountered a shortage of tritium

#33

Post by tlb »

areoform wrote: post #12

Just a quick reminder, we already have practical fusion with tens of thousands of years of runway available to us today. We choose not to do it because it sounds dangerous and it’s not politically expedient. For those unfamiliar, I am talking about Project PACER. The fusion reactor proposed by Teller after the creation of the thermonuclear weapon. It may sound fanciful but it’s based on a simple precept. We can alrea…

It lacks the key advantage of fusion reactors over fission: not contaminating its working fluid with radioactive isotopes. For something like PACER, you have to extract the heat by running the hot fluoride through heat exchangers to run steam turbines. This is difficult and expensive to make safe. Like with conventional fission reactors, you have to be extremely sure your heat exchangers will last 50 years with zero leaks, because you can't touch them once the system has been running. And leaks are extremely dangerous. So every weld has to be triple-inspected and so on.

A second disadvantage is that the parts would undergo constant thermal cycling. Conventional reactors are run at a very steady output level to handle base load, because turning them up and down regularly would cause the moving parts to fatigue and crack over time.

Re: Nuclear fusion has encountered a shortage of tritium

#34

Post by R0b0t1 »

cogman10 wrote: post #25
jandrese wrote: post #23

Earlier quoted context omitted.

Some of the heartburn about PACER is that there are failure modes that can only be described as catastrophic.

No shit. Turns out a daily detonation of a fusion bomb tends to wear on things and when those things fail... you've just detonated a fusion bomb.

But surely the payoff would justify a 10-20x overbuild for the containment and research into extremely small payloads, no?

Re: Nuclear fusion has encountered a shortage of tritium

#35

Post by tlb »

areoform wrote: post #32
cogman10 wrote: post #25

Earlier quoted context omitted.

No shit. Turns out a daily detonation of a fusion bomb tends to wear on things and when those things fail... you've just detonated a fusion bomb.

We’re facing a catastrophe. I and others have described elsewhere that the path we’re on is much, much worse than even the most dire of predictions the IPCC makes. https://news.ycombinator.com/item?id=30947756 Teller et al anticipated your objection. It’s why the reactor is supposed to dig into sold rock. If there’s a catastrophic failure then it’s yet another subsurface nuclear test. And the more advanced designs co…

The same line of reasoning says that we should build conventional light- or heavy-water reactors. The risk is minimal. And they're (a) tested and (b) much cheaper than PACER.

Re: Nuclear fusion has encountered a shortage of tritium

#36

Post by namesbc »

areoform wrote: post #12

Just a quick reminder, we already have practical fusion with tens of thousands of years of runway available to us today. We choose not to do it because it sounds dangerous and it’s not politically expedient. For those unfamiliar, I am talking about Project PACER. The fusion reactor proposed by Teller after the creation of the thermonuclear weapon. It may sound fanciful but it’s based on a simple precept. We can alrea…

The project was terminated because there were formidable technical issues, it wasn't economically profitable, and there was a real possibility of catastrophic failure that could not be mitigated.

https://books.google.com/books?id=4QsAAAAAMBAJ&pg=PA18#v=one...

Re: Nuclear fusion has encountered a shortage of tritium

#37

Post by jandrese »

cogman10 wrote: post #25
jandrese wrote: post #23

Earlier quoted context omitted.

Some of the heartburn about PACER is that there are failure modes that can only be described as catastrophic.

No shit. Turns out a daily detonation of a fusion bomb tends to wear on things and when those things fail... you've just detonated a fusion bomb.

They actually want to detonate a H-Bomb every 45 minutes, all day every day. 32 nuclear explosions every day.

One does have to appreciate how these guys took anti-proliferation concerns with the nuclear industry and said "fuck it, everyone knows we're only doing this to make bombs, so lets make a shit ton of bombs". No more concerns about terrorists getting their hands on some yellowcake and making a dirty bomb. Now they have a full up H-Bomb factory moving so much product that security can get complacent.

Re: Nuclear fusion has encountered a shortage of tritium

#38

Post by Manuel_D »

areoform wrote: post #12

Just a quick reminder, we already have practical fusion with tens of thousands of years of runway available to us today. We choose not to do it because it sounds dangerous and it’s not politically expedient. For those unfamiliar, I am talking about Project PACER. The fusion reactor proposed by Teller after the creation of the thermonuclear weapon. It may sound fanciful but it’s based on a simple precept. We can alrea…

> Dropping about two bombs a day would cause the system to reach thermal equilibrium, allowing the continual extraction of about 2 GW of electrical power.

So the idea is to drop 2 nuclear bombs per day to get about as much energy as one gets from a pair of nuclear fission reactors? I seriously doubt that's cost-competitive with fission power.

Re: Nuclear fusion has encountered a shortage of tritium

#39

Post by toomuchtodo »

gfodor wrote: post #28
nh23423fefe wrote: post #18

Earlier quoted context omitted.

Instead of asking oblique rhetorical questions, you could actually make a meaningful statement.

It seems like every fusion post is bound to have at least one commenter point out that the sun is a working fusion reactor, as if literally anyone in these threads will learn something from this observation.

Roughly $50 billion has been spent globally on fusion research since the 1950s with nothing material to show for the effort; at what point do you stop throwing good money after bad? This strikes me as the learning from these posts.

Re: Nuclear fusion has encountered a shortage of tritium

#40

Post by pvg »

areoform wrote: post #12

Just a quick reminder, we already have practical fusion with tens of thousands of years of runway available to us today. We choose not to do it because it sounds dangerous and it’s not politically expedient. For those unfamiliar, I am talking about Project PACER. The fusion reactor proposed by Teller after the creation of the thermonuclear weapon. It may sound fanciful but it’s based on a simple precept. We can alrea…

It would have meant the end of nuclear arms control and non-proliferation efforts, an already difficult process. So yeah, that tends to arouse considerable negative responses.
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