# ITER is going to work?

1. Nov 22, 2006

### Mk

Well, it looks like everybody decided to do it! I didn't think that would happen.

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2. Nov 23, 2006

### EL

That's good news!

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3. Nov 23, 2006

That's what the $12.8 billion (€10 billion) is supposed to determine. There are many skeptics. 4. Nov 23, 2006 ### Mk I meant that they actually decided to do it! This isn't going to be like the SSC is it? 5. Nov 23, 2006 ### Astronuc ### Staff: Mentor Perhaps not. I'm sure the device will be constructed, rather than just dig a$2 billion hold in the ground.

Whether or not it will produce a sustainable fusion reaction, or one that will produce inexpensive electricity is another matter. I hope it works, but to be feasible long term, it needs to move away from DT and use DD or DHe3[/sub], but the He3[/sub] costs alot and there is little indigenous supply. Getting it from the moon just isn't feasible.

I think they need to develop a HICP process.

6. Nov 23, 2006

### Rach3

7. Nov 23, 2006

Well, we got a high of a .7Q rating in our current fusion research, and so I have no problem expecting at least 2Q in ITER. Like Astronuc said

The money probably has gone into many reports about whether ITER will be a big success or not.

By the way, those who don't want ITER such as Greenpeace (or so I think) need to be introduced back to their old Physics books they had in High School, since they are stupid enough to think that fusion produces radioactive wastes.

8. Nov 23, 2006

### theCandyman

Greenpeace's argument is actually that this will take funding away from other renewable energy that they support, research on wind and solar power.

9. Nov 23, 2006

### Alkatran

Because everyone knows you should put your eggs in one basket, of course. As if 12 billion divided 7 ways over years mattered that much to the States.

10. Nov 23, 2006

### Rach3

I certainly do not support the Greenpeace radicals and their ignorant, destructive ideology. That aside - DT fusion has a much worse radiation problem than plain fission. It's not the endproducts of the DT reaction itself (plain, stable Helium); it's what all the reactor vessel and shielding becomes when exposed to very high-energy neutrons (neutron-induced radioactivity). Plus, there's that whole issue of metals becoming unpredictably brittle (wikipedia) on prolonged exposure to neutrons. And there are other surprises in the material science of high neutron flux, such as the buildup of Wigner energy (wiki) which resulted in the Windscale fire in '57.

These engineering issues will eventually be overcome (I expect); but we certainly don't have the answers yet, that's one of the objectives of the ITER experiment. And to say that desiging a reactor to withstand the high-energy neutrons of nuclear fusion is trivial, or cheap, or doesn't produce a bargeload of nuclear waste, is a gross misrepresentation of the endeavor.

11. Nov 23, 2006

### Rach3

And speaking of "putting all eggs in one basket", we seem to have dropped an egg somewhere back in the 70's. It's the ordinary chicken egg of nuclear fission - plain, old, unexciting, but edible and http://www.iowaegg.org/iowaeggcouncil.asp?idSection=5 [Broken] and using all proven technologies and existing expertise. We don't have to sit around idly while basic research drags on in fusion and cheap solar-electric materials - we could start building economical, carbon-neutral fission plants as early as tomorrow morning. (And that's only a slight rhetorical excess) And we have cheap, cheap fuel, and existing companies with experience in reactor vessels, and a whole shopping list of advanced techniques to drive down costs further (liquid sodium cooling). And we have a world-changing cataclysm of a greenhouse effect as incentive.

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12. Nov 25, 2006

### Staff: Mentor

Well, there is already a lot of knowledge already of embrittlement and swelling of metals (particularly special steels and alloys) when exposed to high neutron fluences. Oak Ridge and Pacific Northwest Labs have had ongoing programs in this area. Nevertheless, the 14.1 MeV neutron from DT fusion does mean that materials will become activated over time. DD is better, but one still gets some DT, since T is a product in about 50% of DD fusions.

The Wigner energy is an issue with graphite, not metals.

13. Nov 26, 2006

### Mk

So in pebble-bed reactors Wigner energy could present problems?

14. Nov 26, 2006

### Staff: Mentor

No, because PB's run at high temperature, ~600-800°C, which is well above the 250°C annealing temperature of graphite, so Wigner energy is not an overwhelming safety issue. Nevertheless, it will be reviewed.