A couple of days ago China announced plans to complete its tokamak fusion reactor by April of this year. China will start experimenting with the reactor – designated HT-7 – this summer with the hope of hitting a magic breakeven point that has, to date, never been reached in fusion research anywhere. They hope to produce more power than is required to contain the reaction.
Tokamak is a Russian acronym meaning “toroidal chamber in magnetic coils.” A tokamak reactor contains a giant donut-shaped magnet used to contain plasma within the reactor.
The United States has been betting on the success of a different tokamak project: the International Thermonuclear Experimental Reactor (ITER). The ITER has been in the design and planning phase so long (since 1985!) that China may have already leap-frogged the rest of the world with its cheaper reactor.
…Construction [on ITER] is expected to begin in 2008 and finish in 2016. ITER is designed to generate 500 MW (about 10 times the record held by JET) and will hopefully produce more energy than is required to keep the plasma heated and confined…
Which will mean little if China has already accomplished this with a reactor that cost 1/20th the price of the ITER.
Tokamak reactors are powered by deuterium harvested from seawater.
After nuclear fusion, the deuterium extracted from one liter of sea water will produce energy equivalent to 300 liters of gasoline.
This would be a practically inexhaustible supply of power, and China probably has the lead in deuterium fusion research at the moment. Maybe the U.S. will compete with a different form of fusion.
[Deuterium fusion critics] have noted that the neutrons released in the deuterium-tritium fusion would create secondary radiation within the metallic parts of the reactor chamber. This secondary radiation would create radiological waste disposal problem, and would also shorten the life of the components in the reactor through radiative metal fatigue…
If China gets their reactor working, it won’t be easy to operate or maintain. Fortunately, there is the possibility of a cleaner, easier to manage fusion fuel.
[Twenty years ago fusion expert Gerald Kulcinski] and a group of scientists met at a retreat south of Madison, Wisconsin to discuss the problems with the deuterium-tritium fuel cycle for fusion. They talked over what the options are for a better fuel. Helium-3 is what they came up with.
In fact, helium-3 is the perfect fusion fuel. It can produce an incredible amount of power with absolutely no radioactivity. And a helium-3 fusion reactor won’t have the same containment issues either.
Professor Kulcinski’s lab is running the only helium-3 fusion reactor in the world. He has an annual research budget that is barely into six figures and allows him to have five graduate research assistants working on the project. Compared to what has been spent on other fusion projects around the world, the team’s accomplishments are impressive. Helium-3 would not require a tokomak reactor like the multibillion-dollar one being developed for the international ITER project. Instead, his design uses an electrostatic field to contain the plasma instead of an electromagnetic field.
There’s a catch. Unlike the deuterium, which can be obtained from the ocean probably forever, there are only a few hundred kilograms of helium-3 on Earth. You have to go to the Moon to find helium-3 in useful quantities.
In January of 1986 Professor Kulcinski and his group contacted the Lunar and Planetary Institute at the Johnson Space Center. The soil samples from the Apollo missions are stored there. Every sample from the Moon had helium-3 in it. It didn’t matter if the sample was collected from right on the surface or from a core sample a meter deep…
Theoretical calculations of helium-3 abundances on the Moon suggest that it may have enough to supply current world energy demand for thousands of years. Even further out, the gas giant planets contain enough helium-3 to power human civilization for millions of years.
In the short run deuterium will be seen as the miracle fuel. We certainly have plenty of it right here at home. But it will wear out reactors and leave us with some nasty radioactive waste. Ultimately we will turn to helium-3 because it is abundant (if you look in the right places), safe, and manageable.