Mining for Helium 3 on the Moon

[shuttle_rtf]

One of our posters brought this up in a post, and I found it interesting. Wonder if anyone can elaborate? By the way, I said "mining" as a guess on the extraction.<br /><br />Snippet:<br /><br /> />The Moon could be used for the exploitation of Helium 3 resources there. <br /><br />He3, if you don't know already, is used in Nuclear Fusion Reactors, which is the newer Nuclear power cousin to regular Nuclear Fission Reactors in use today. Theoretically, Fusion offers cleaner, cheaper and safer Nuclear production than Fission does. <br /><br />He3 however, is very rare on the Earth, and so is very expensive. I understand it is really quite plentiful in the lunar regolith, and an economical model already exists showing that mining for it on the moon would be an financially profitable source of fuel.<<br />

 

[nacnud]

It would give a lower radiation (no fast neutrons) fusion reaction in a Tokomak (torus) reactor. This would lower the need for shielding and help the reactor last longer than an equivalent deuterium reactor. Helium-3 undergoes the following reaction, among others, although this is the one most promising to fusion engineers:<br /><br /> D + ³He -> ⁴He (3.7 MeV) + p (14.7 MeV) <br /><br />note D = Deuterium = ²H (Hydrogen with a neutron)<br /><br />It is all a bit moot thought as a break even fusion reactor is at least a decade, probably more, away and a commercial one even further off. <br /><br />I think that the reason why the Moon has ³He is that the Moons surface is bombarded by the Solar wind and ³He becomes trapped in the Luna regolith from which it can be extracted by heating.<br /><br />Oh and ³He differs from normal Helium by having one neutron rather than two.<br /><br />Wikipedia on Helium 3<br />SCD Researchers and space enthusiasts see helium-3 as the perfect fuel source.<br />ITER (fusion reactor)<br /><br />

 

[shuttle_rtf]

Thanks! Unless I've been missing it, it's the first I've heard of this potential resourse on the Moon.

 

[radarredux]

> <i><font color="yellow">It is all a bit moot thought as a break even fusion reactor is at least a decade, probably more</font>/i><br /><br />Given that a manned landing is 13 years away and any serious mining for Lunar resources is probably closer to two decades away, the timing might be very good. By a number of measures, by 2015-2025 petrol production will probably have peaked or at least slipped behind demand, so new energy sources will be in demand. At that point, every country will demand the right to nuclear energy (as Iran is saying now).<br /><br />I also believe He3-based fusion reactors would not produce dangerous byproducts that would be a problem for the environment or useful for terrorists' dirty bombs.<br /><br />Finally, throw in Platinum Group Metals (PGMs) -- important to fuel cells for a hydrogen economy, relatively rare on Earth, but probably relatively common in the Moon. The book Moonrush provides a plausible argument why this should be the first economic development effort on the Moon.<br /><br />In conclusion, He3 for fusion reactors and PGM for fuel cells could provide an incredible opportunity on Earth to create and use vast amounts of energy that is low in pollution, Global Warming friendly, and does not support terrorism. It may take 20 years before we see the first fruits of such effort, but it seems like a no brainer.</i>

 

[nacnud]

Well you need 10 times the temperature for ³He fusion ignition compared to normal fusion, and you also need a lot of regolith. To produce roughly enough to supply the US with energy for a year 300 thousand tonnes of lunar soil would need to be heated to 800 degrees C. That capability will take longer than 20 years to develop.

 

[tmccort]

My money is on inertial confinement fusion.<br /><br />http://en.wikipedia.org/wiki/Laser_fusion

 

[nacnud]

May but I though that was just a way of generating data for bomb designs.

 

[tmccort]

<br />What is just a way of generating data for designs? Designs of what?<br /><br />Sorry, I don't understand.

 

[nacnud]

typo, fixed now

 

[tmccort]

Oh, well yes. The National Ignition Facility for example is used mostly for nuclear weapons research unfortunately.<br /><br />However, the Europeans have just proposed a new £500m facility called HiPER which sounds pretty interesting.<br /><br />http://www.theregister.co.uk/2005/09/05/civilian_laser_fusion/

 

[radarredux]

> <i><font color="yellow">and you also need a lot of regolith</font>/i><br /><br />I suspect giant strip mining operations will be kept on the far side of the moon in order to avoid public angst. <img src="/images/icons/shocked.gif" /></i>

 

[lampblack]

You might be right about that. It does seem odd, though, that someone might object to stripmining the moon -- it's not like the machinery would be ripping up the greenery or despoiling the streams. <img src="/images/icons/wink.gif" /><br /> <div class="Discussion_UserSignature"> <font color="#0000ff"><strong>Just tell the truth and let the chips fall...</strong></font> </div>

 

[thinice]

One should be extremely concentrated on space shuttles to learn about He3 for the first time now, since it is mentioned in almost every article and discussion on the Moon exploration from time immemorial. <img src="/images/icons/smile.gif" /><br />Anyway, the earliest ITER Tokamak, which is to be built in southern France according to the agreement reached this summer, could be running in 2015, and the first power plant based on the ITER design - no earlier than 2050. And in no way it could use He as a fuel. So there is absolutely no rush for He3.

 

[shuttle_rtf]

>One should be extremely concentrated on space shuttles to learn about He3 for the first time now, since it is mentioned in almost every article and discussion on the Moon exploration from time immemorial<<br /><br />Guilty as charged, officer <img src="/images/icons/smile.gif" /><br /><br />Women, beer, football (soccer), women, Shuttles (plus other launch related vehicles) and women. Anything else pretty much isn't on my radar <img src="/images/icons/wink.gif" /><br /><br />Interesting subject all the same.

 

[tap_sa]

<font color="yellow">"To produce roughly enough to supply the US with energy for a year 300 thousand tonnes of lunar soil would need to be heated to 800 degrees C."</font><br /><br />It takes a bit more than that. Harrison Schmidt estimated He3 concentration to be 20-30 parts per billion. If we take the lower end as conservative average yield, the 25 tonnes annual US consumption requires siphoning through 1250 million tonnes (1.25e12 kg) of regolith. That's 278 square kilometers (107 square miles) if we assume digging three meters deep and 1.5g/cc density. That is a lot of area and mass to process, but the product's estimated value runs at ~$4 billion per tonne. There would be other nice byproducts too, like 62,500 tonnes of hydrogen (from said US dig assuming conservative 50ppm concentration).

 

[nexium]

Ten times the temperature will be difficult if higher pressure is also needed.<br />A few thousand tons of regolith should be enough to get the first fusion reactor on the grid 24/7. 800 degrees c is likely the maximum yield temperature. Somewhat cooler may yield half as much helium three with the help of ultra sonic vibration of the regolith. The vacuum on the moon should make 800 degrees c easier to achieve.<br />I suspect large scale projects on the moon will require extensive and costly support from Earth until 2050 or later, even if we optimise moon colonization. Neil

 

[pmn1]

<font color="yellow">Thanks! Unless I've been missing it, it's the first I've heard of this potential resourse on the Moon.</font><br /><br />Got to admit, that surprises me a lot given your enthusiasm for space...<br /><br /><br />Following on from Tokomaks and IEC devices, what about muon catalysed fusion - works best at about 900 centigrade IIRC... <div class="Discussion_UserSignature"> </div>

 

[nacnud]

From Wikipedia: <font color="yellow">Muon-catalyzed fusion is a process allowing nuclear fusion to take place at room temperature. Although it can be produced reliably with the right equipment and has been much studied, it is believed that the poor energy balance will prevent it from ever becoming a practical power source.<br /><br /><font color="white">Nice idea but it seem like a non starter, these more at the link.</font></font>

 

[pmn1]

<font color="orange"> From Wikipedia: Muon-catalyzed fusion is a process allowing nuclear fusion to take place at room temperature. Although it can be produced reliably with the right equipment and has been much studied, it is believed that the poor energy balance will prevent it from ever becoming a practical power source. <br /><br />Nice idea but it seem like a non starter, these more at the link. </font><br /><br /><br />I'm a bit wary of Wikepedia after reading their article on the Bismarck<br /><br />http://en.wikipedia.org/wiki/Bismarck_class_battleship<br /><br />The Bismarck class battleships were a class of extremely powerful capital ships intended by the German Admiral Erich Raeder to constitute a major part of the battleship component of Germany's failed "Plan Z." The aim of this plan was to create a surface fleet able to compete against the British Royal Navy for supremacy over the world's oceans, or at least over the Atlantic and possibly — with the help of the Italians, who were also in the midst of a battleship-building program — the Mediterranean Sea.<br /><br />Bismarck and Tirpitz, the first two ships of this class, were laid down in 1936 and launched three years later, nominally 35,000 tonnes each in accordance with the 1923 Washington Naval Treaty. In reality, each was considerably heftier weighing in at 43,000 tonnes. Although Bismarck and Tirpitz were nearly identical insofar as basic configuration and dimensions, Bismarck has become something of a naval legend while Tirpitz led a comparatively unglamorous life. A rough maritime comparison might be made between the White Star Line's sister liners Titanic and Olympic, the former, like the Bismarck, going down on its maiden voyage and into popular mythology, while the latter, like the Tirpitz, served much longer but with far less excitement.<br /><br />The Bismarck class embodied much of what made Germany's World Wa <div class="Discussion_UserSignature"> </div>

 

[nacnud]

For basic BBcode stuff see the FAQ<br /><br />For eye bleeding HTML and stuff see The UBBCode, HTML and smiley thread. <br /><br />Enjoy <img src="/images/icons/smile.gif" />

 

[SpaceKiwi]

It occurs to me there are some damn well informed people contributing in this thread. Thanks to nacnud for answering most of the questions I had following SRTF's original post.<br /><br />If I can ask a stupid question now, an H3-powered reactor still produces radioactivity lethal to humans, but of a variety which is less dangerous relative to current reactors? <div class="Discussion_UserSignature"> <p><em><font size="2" color="#ff0000">Who is this superhero?  Henry, the mild-mannered janitor ... could be!</font></em></p><p><em><font size="2">-------------------------------------------------------------------------------------------</font></em></p><p><font size="5">Bring Back The Black!</font></p> </div>

 

[tap_sa]

I guess it's the 6.5 times more intense sunshine versus 700K peak temperatures (moon peaks 'only' at ~400K). The intense radiation means more He3 candidates to embed themselves into the surface, but the higher temperature surely causes more outgassing. How much more, beats me.<br /><br />We'll know better in 2011 when MESSENGER inserts itself into orbit around Mercury.<br /><br />

 

[henryhallam]

Any fusion reactor produces vastly less radioactive waste than a fission reactor, especially if you count the waste produced during manufacture and processing of fission fuel.<br />"conventional" fusion reactors such as the ITER generally use a mixture of D and T which gives a neutron-producing reaction. The neutrons then "transmute" any element they collide with, often into an unstable or radioactive product. However this is put to good use in the proposed commercial designs, where the core is wrapped in a "mantle" of molten Lithium. The neutrons from the D-T reaction in the core are absorbed by the lithium which causes it to heat up (energy is extracted this way). At the same time, the neutrons which hit the Li nuclei transmute them and a decay occurs giving more tritium, hence giving you a handy supply of tritium for your reactor.<br />Nevertheless some neutrons get absorbed by the walls of the reactor's vacuum chamber, its magnets and ancilliary equipment, gradually making them radioactive. When it comes time to change the equipment or replace the wall panels, you have a certain amount of relatively low-level radioactive waste to dispose of. But it's a whole lot less of a headache than the high-level and medium-level waste produced by fission reactors.<br /><br /><br />D-He3 reactions are aneutronic, that is they do not produce neutrons. Therefore there is nothing to produce any radioactive waste. EXCEPT, in order to get D-He3 reactions you must have a mixture of deuterium and He3 in the chamber. Therefore you will get some "side-reactions", primarily D-D, which do produce neutrons. (BTW as an aside, it is possible to build a device that can do D-D fusion, albeit terribly inefficiently, in your garage). However techniques such as neutral atom injection can be used to reduce these side-reactions to a minimum so a D-He3 reactor would be very clean indeed, if not quite perfectly so.<br /><br />

 

[barrykirk]

Actually a D-D reaction would not produce any neutrons.<br /><br />Each D contains 1 proton and 1 neutron.<br /><br />Each He4 contains 2 protons and 2 neutrons<br /><br />The reaction is D + D = He4 + energy.<br /><br />The only reason tritium is used is that it's a lot easier to fuse a mixture of D + T than pure D.

 

[jatslo]

Okay, this important: lithium (liquid medium) as opposed to water that is utilized in traditional fission reactors is interesting for numerous reasons. Charged particles exceeding the speed of light -(c) within the medium will create a release a cone shaped boom of energy that is characterized by the velocity -(v) ratio of the two subjects (energy and matter). Now, liquid lithium is at what temperature? I am looking for sublimate energy or matter to utilize as propulsion, but I need a new zero resistive super-medium that can conduct extreme heat, pressure, and matter.<blockquote><font class="small">In reply to:</font><hr /><p><font color="black">The neutrons then "transmute" any element they collide with, often into an unstable or radioactive product. However this is put to good use in the proposed commercial designs, where the core is wrapped in a "mantle" of molten Lithium. The neutrons from the D-T reaction in the core are absorbed by the lithium which causes it to heat up (energy is extracted this way).</font><p><hr /></p></p></blockquote>Yes, I realize lithium is metallic; however, if we could convert metallic lithium to lithium gas and then convert that lithium gas into liquid lithium, we could then utilize liquid lithium as a medium other than water, or is the liquid lithium flammable? If I could come up with a new medium, other than water, that would be a great accomplishment in terms of space requirements. Lithium burns white hot and transmutes; what is happening is the lithium is converting to gas and the gas is burning, so how do I convert the metal to gas without burning the gas? At what temperature does the metal convert to gas?