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The Energy Race

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.

helium-3 moon map

This lunar map shows heavy deposits of helium-3 in red.


it seems that certain nations recognize the need for helium-3 harvesting on the moon ...


Maybe the Energy Race will pave the way for the Helium Rush. I'd like to believe that the rush would lead to lunar settlement, and that the first cities on the moon will be San Francisco- or Seattle- style boom towns that emerge from the economic activity around prospecting and mining. But this gold rush will more likely be a race to get the best roboticized Helium 3 operation up and running, requiring little or no permanent settlement.

I wonder if anyone is working on that yet?

"The University of Wisconsin is working on a design of an automated lunar miner to rove across the surface of the Moon to extract helium-3 and life-support volatiles."

Tokamak reactors are powered by deuterium harvested from seawater.

Actually, they're fueled by deuterium and lithium. The lithium is essential, since the lithiun blanket is where most of the tritium that will be 'burned' is produced. The net reaction is D + 6Li --> 2 4He (ignoring various less important reactions).

I have considerable misgivings about tokamaks. They're big, complicated, and expensive, and they don't scale down terribly well. These are not features that lead to rapid technological advance. Unless their economics can be dramatically improved I expect them to be uncompetitive with contemporary n-th generation fission reactors, particularly when potential customers throw in a risk premium for an immature technology. The engineering problems of keeping a tokamak running at high power for 30 years will be immense, in part because the reactor structure will quickly become far too radioactive for hands-on maintenance, and in part because the entire 'first wall' will have to be replaced every few years due to neutron damage (D-3He could ameliorate that last problem, but increases the reactor cost greatly due to the much lower reactivity of this fuel combination and much higher plasma pressure required.)

The lunar Helium 3 idea is a totally crackpot idea.

Let's first not not look at the technological difficulty, just look at the availability issue. According to this source:

1.There are one million tons of He3 on the top lunar soil, no deeper than a few feet.

2.These one million tons of He3 can provide the U.S. for a one thousand years of electricity.

The number sounds big but they actually are NOT quite that big. The U.S. only consumes 1/4 of the world's total electricity, or maybe less. So to provide the whole world with electricity, the one million ton lunar He3 is only good for 250 years, not 1000 years.

Now, the world's electricity consumption is only 1/6 of total energy consumption. So to provide the world with all energy supply, not just electricity, you need to further divide the number by 6. Which results in 43 years of supply.

Only 43 years of energy supply, even if you mine every little bit of He3 on the moon 100%. That doesn't look like an encouraging solution.

Now, how do you mine the He3 from the moon? Just cook the lunar soil to 700C and it will come out. Sounds easy? But's it's easier said than done. The He3 is uniformly distributed on the whole surface of the moon, to a depth of one meter. The moon is a pretty big place. Let's calculate how much lunar soil you need to dig up and cook:

The moon's radius is 1738,000 meters. So its surface area is 4*PI*1738000^2 = 3.8x10^13 M^2. Multiply by one meter depth, that's a volume of 3.8x10^13 M^2, at about 5 kilogram mass per cubic meter, that's a total mass of 1.9x10^17 kilogram.

You are talking about cooking 190 trillion tons of lunar soil to 700C, in order to extract just one million ton of He3. The concentration of He3 is only 5 parts per billion!!! Each ton of lunar soil cooked will yield just 5 miligram of He3.

Where do you get all the energy to cook 190 trillian tons of lunar soil to 700C temperature? The extracted He3, even if all their energy is released, is far from being enough to even cook the soil from which they were extracted.

The whole history of humanity has never cooked anything remotely approaching 170 trillion tons, to any temperature remotely close to 700C. All the hot water for bath/shower humen ever cooked (which is to no more than 50C), from the Roman era to today, is about one trillion ton of hot water.

It's a complete ridiculous idea to believe that extracting He3 from lunar surface could be of any usage in terms of energy.


While I agree that the difficulty of extracting lunar 3He is usually glossed over by advocates, and I agree its practicality is dubious, the situation is not quite as extremely bad as you depict:

  • The density of regolith is more like 2 g/cc rather than 5 as you assume.
  • 3He is primarily in the small diameter component, so you can save energy by sieving to remove large chunks.
  • 3He is also concentrated in the ilmenite fraction, so regions high in ilmenite are more easily processed.
  • 3He concentrations depend on the equilibrium between the rate of implantation and the rate of diffusion out of regolith grains. The latter is slower at low temperature, so 3He concentrations may be higher near the poles.
  • Counterflow techniques can be used to recycle the heat, so a given unit of heat can process many masses of material before being radiated away.

The limit on the total amount still applies, and becomes even stronger if one is limiting oneself to only the richer deposits. The advocates would claim that we'd be mining Uranus (or, perhaps, the atmosphere of an even more suitable, but yet undiscovered, large Kuiper belt planet) by the time the lunar 3He had run out.

Yeah, it's a stretch.


You don't have to mine the whole Moon before the first check comes in.

How to cook the dust? The Sun shines on the Moon. Use a solar cooker.

We could power the entire world for only 43 years? You're right, hardly worth pursuing.


How many times have we had to revise the estimate of how many years of petroleum we have left?

Quantoken: How do you come up with the figure of 1000 years? Every estimate I have seen has the total He3 potential being on the order of 10,000 years. If we use your reasoning, starting at 10,000 years, instead of 1,000, the Earth could be powered by He3 from the moon for 430 years. That is certainly worth pursuing.

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