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Posted: Tue Sep 09, 2008 6:27 pm
by Alchemist
Someone correct me if I'm wrong but hasn't it been understood from the beginning that "Phase 2" of this project would be to proceed directly to the 100MW demo reactor assuming WB-7 gave results similar to WB-6?

If that was the case then I'd personally interpret the "plan going forward" and "moving on to the next phase" comments at face value. It sounds to me like we're being told that the project is moving ahead as planned without them actually saying that. The ambiguity provides a measure of deniability should things go south, but I'd like to remain optimistic.

Posted: Tue Sep 09, 2008 7:15 pm
by scareduck
Alchemist wrote:Someone correct me if I'm wrong but hasn't it been understood from the beginning that "Phase 2" of this project would be to proceed directly to the 100MW demo reactor assuming WB-7 gave results similar to WB-6?

If that was the case then I'd personally interpret the "plan going forward" and "moving on to the next phase" comments at face value. It sounds to me like we're being told that the project is moving ahead as planned without them actually saying that. The ambiguity provides a measure of deniability should things go south, but I'd like to remain optimistic.
Even if things look good, the problem remains the politics of funding.

Posted: Tue Sep 09, 2008 9:00 pm
by MSimon
Alchemist wrote:Someone correct me if I'm wrong but hasn't it been understood from the beginning that "Phase 2" of this project would be to proceed directly to the 100MW demo reactor assuming WB-7 gave results similar to WB-6?

If that was the case then I'd personally interpret the "plan going forward" and "moving on to the next phase" comments at face value. It sounds to me like we're being told that the project is moving ahead as planned without them actually saying that. The ambiguity provides a measure of deniability should things go south, but I'd like to remain optimistic.
There are still sub steps. - Building a continuous operation WB-7. Building a 2X (linear dimensions) pulsed job.

I don't think you can just jump to light speed. Too many engineering unknowns.

Posted: Tue Sep 09, 2008 9:02 pm
by MSimon
scareduck wrote:
Alchemist wrote:Someone correct me if I'm wrong but hasn't it been understood from the beginning that "Phase 2" of this project would be to proceed directly to the 100MW demo reactor assuming WB-7 gave results similar to WB-6?

If that was the case then I'd personally interpret the "plan going forward" and "moving on to the next phase" comments at face value. It sounds to me like we're being told that the project is moving ahead as planned without them actually saying that. The ambiguity provides a measure of deniability should things go south, but I'd like to remain optimistic.
Even if things look good, the problem remains the politics of funding.
I am quite confident that the Congress would be willing to spend $200 mn a year for 5 years.

Posted: Tue Sep 09, 2008 9:10 pm
by Helius
Alchemist wrote:Someone correct me if I'm wrong but hasn't it been understood from the beginning that "Phase 2" of this project would be to proceed directly to the 100MW demo reactor assuming WB-7 gave results similar to WB-6?
I think a 100MW "demo" is way over the top, since they have no way of knowing the hurdles required. I'd like to see that scale of machine built but with an architecture that will be conducive to testing and measurement rather that a shot at power.

Steady science success will not shut down the project, failure will. The goal should be data, not an attempt at power.

Posted: Tue Sep 09, 2008 9:11 pm
by Barry Kirk
If things look good, people will find out. Congress would have a lot of explaining to do if they don't fund this.

At this point, I'm confident that Polywell's will work. The question is will it be economical.

As for ITER, it is beyond a shadow of a doubt that Tokamaks will never be economically viable. Just the cost of the Tokamak alone is horrible. But the cost of the Tritium may also be very significant.

Can a Tokamak breed all of it's own Tritium or does it need to be supplemented?

Posted: Tue Sep 09, 2008 9:19 pm
by Helius
Barry Kirk wrote: Can a Tokamak breed all of it's own Tritium or does it need to be supplemented?
I heard that a Tokamak power plant was to breed 1.05X it's own tritium requirements. Hmmmm. yea, right.

Posted: Tue Sep 09, 2008 9:20 pm
by MSimon
Barry Kirk wrote:If things look good, people will find out. Congress would have a lot of explaining to do if they don't fund this.

At this point, I'm confident that Polywell's will work. The question is will it be economical.

As for ITER, it is beyond a shadow of a doubt that Tokamaks will never be economically viable. Just the cost of the Tokamak alone is horrible. But the cost of the Tritium may also be very significant.

Can a Tokamak breed all of it's own Tritium or does it need to be supplemented?
Breeding is supposed to occur at a rate of 10% above fuel consumption with a Li6 blanket. Not a lot of margin for error in that.

Posted: Tue Sep 09, 2008 9:25 pm
by Barry Kirk
Well the DT reaction produces a 17 Mev really fast neutron.

n (fast) + Li7 -> H3 + He4 + n (slow) (endothermic)

n (slow) +Li6 -> H3 + He4 + 4.8 MeV (exothermic)

Providing 2 Tritium for each fast input neutron assuming no losses.

1.05... Maybe... Too soon to tell.

Posted: Tue Sep 09, 2008 9:31 pm
by Barry Kirk
I don't know how much energy the first reaction consumes. It does have the minor advantage of acting as a moderator.

The second reaction does provide a lot of output energy.

I wonder, if they are using the energy released from the Li6 Tritium breeding to push the Tokamak over the edge of being a net power producer? :wink:

Posted: Tue Sep 09, 2008 10:17 pm
by Roger
MSimon wrote:
There are still sub steps. - Building a continuous operation WB-7. Building a 2X (linear dimensions) pulsed job.
There seems to be 2 paths to take, 1) right to WB-100, or as Simon says the sub steps. I tend to side with Simon, though Dr Nebel wants WB-100, and that works for me too.

A WB-100 that goes to net power would make history, thats a game changer. Also a LN2 cooled WB capable of runs on the order of 100's of seconds, can be a great platform to use to develop a fuel injection system. And would be able to take a stab at PB-11, Proof of PB-11 fusion makes history and is also a game changer. Short of a WB-100 a WB twice the size of WB-7, can prove scaling, which is vital. A Dodec with the same overall volume of MaGrid as WB-7 can prove that the dodec is supposed to be 3-5x better.

I dont see one path as bad and the other as good.

Posted: Wed Sep 10, 2008 12:09 am
by TallDave
There are still sub steps. - Building a continuous operation WB-7. Building a 2X (linear dimensions) pulsed job.
Do you know this for sure? I understood Nebel to mean that given the givens, they might as well go ahead and give WB-100 a shot, but maybe you have a better understanding of where they are on this, or perhaps things have changed.

Or, of course, perhaps I simply misunderstood him.

Posted: Wed Sep 10, 2008 12:12 am
by TallDave
As for ITER, it is beyond a shadow of a doubt that Tokamaks will never be economically viable. Just the cost of the Tokamak alone is horrible. But the cost of the Tritium may also be very significant.
Well, never say never. It may be that by the time the time DEMO rolls around in 2040 or so, toks do make economic sense. A lot would have to happen, but it's a long time and things are changing faster than ever.

Posted: Wed Sep 10, 2008 12:16 am
by Helius
There seems to be 2 paths to take, 1) right to WB-100, or as Simon says the sub steps. I tend to side with Simon, though Dr Nebel wants WB-100, and that works for me too.
I dont see one path as bad and the other as good.
The biggest problem is setting, then breaking, personal expectations of a net power device. I would also guess there are many confinement questions unanswered from the program just being completed, as well as a plethora of great hypotheses involving recirculation, scaling and brem that need to be tested before a net power device is attempted. Once those questions are understood, then perhaps the same test machine could be used to shoot for net power, and begin research on other regimes such as pB11. A 2M (coil) machine could also be used to research other requirements for a production machine such as fuel feeds and Aero's perspective of modularity.

I hope they hold the "net power" card close to the chest, and avoid setting public expectations that would be unnecessary at this early time.

Posted: Wed Sep 10, 2008 12:38 am
by Robthebob
you guys are making me really nervous.