U.S. to Rejoin the ITER Fusion Project

spiro_killglance writes: "BBC news is reporting here, that the USA may be about the rejoin the International Thermonuclear Experiment Reactor project. The USA left the ITER consortinum in 1999 when it bulked at the 10 Billion dollar price tag. Canada, Europe and Japan continued in the project, downscaling it to a cheaper 4.5 Billion dollars. The project claims to be the final step before commcercial reactors are possible, although the price tags might still be daunting to utility companies. ITER is designed to generate bursts of fusion energy, producing over 10 times the ammount of energy used to generate the fusion reaction (a Q factor >10), will not quite reach ignition (a self sustaining fusion reaction, or Q=infinity), but should pave the way for devices that will."

Comments

Yes, I think we do.

[Spamalamadingdong]

As you run up Q, doesn't the radioactive output also rise?

Depends what the reactants are. If you are burning deuterium with tritium (or D-D) you are emitting neutrons (D-D yields He-3 and a neutron, D-T yields He-4 and a neutron). Whether you create radioactives or not depends what those neutrons hit. You can get some neutron spallation (neutron hits something in a nucleus and tosses it out, transmuting the nucleus into something radioactive) or just neutron capture; however, you could control the results by selecting the composition of the materials exposed to the neutron flux. In a D-T burner you are going to have to replace the tritium you burn, which is usually done by capturing the neutrons with lithium. IIRC, Li-6 + n -> He-4 + tritium.

The antinukes would have to be crazy to be worried about neutrinos; their favorite energy source (old Sol) streams countless numbers of them through their bodies every second. This is not to claim that some of these people aren't crazy...

Fusion plasma won't melt a hole in the ground. By the time you dump air into the vacuum of the tokamak torus, the plasma will have been quite thoroughly quenched; you might have a few micrograms of tritium to worry about, but it has a half-life of about 12 years so it isn't much of a concern except over a relatively short term.