Nuclear Power to the People–On the Moon

To Nuke or Not to Nuke the Moon, That is the Multi-Billion Dollar Question

Energy is the lifeblood of civilization.  This is true on Earth as well as for of our outward move into the solar system.  Wherever we go, our actions and our level of success will be dictated by how much energy we have and are able to productively use.  You cannot have an industrial civilization without plentiful energy.  This is true whether this civilization is on the Earth, Moon, or beyond.  With plentiful energy, the stars are at our doorstep.

In the past 20 years of my looking at, reviewing, and analyzing lunar and beyond exploration architectures, my own interests have shied away from nuclear power as part of any architecture as it immediately drives up the price to unaffordable levels and puts a major critical path milestone in the way of success.  Solar power is great for low power outposts and can be implemented without a lot of development time and expense.  However, as we have moved forward in time, there have been a lot of developments in small nuclear power systems that bear examination.  The idea is to trade the value of a low power system powered by solar energy against a high power system powered by a nuclear reactor.

Low Power Industrial Outposts (Solar)

The question becomes, can a low power (solar) lunar infrastructure be built that enables industrialization.  First we have to define what low power means.  Practically, it means between 500 kilowatts to one megawatt of power.  The reason is simple.  We can get about 100 kilowatts per Delta IVH launch to the Moon using “traditional” methods.  We can probably get about 300 kilowatts per launch to the Moon using a solar electric transportation stage and a Delta IVH launch plus the launch to put the SEP up in the first place.  Doing a bit of arm waving the cost for either path will be about $2 billion for five hundred kilowatts and probably about $3 billion using a SEP for a megawatt and about $3.5 billion for a conventional approach.

The question becomes, is 500kw to a megawatt of electrical power sufficient to reach sustainability of a lunar (or anywhere else) industrial outpost.  The answer depends on exactly where the facility is located and the richness of the resources (metals and volatiles) that are in the near vicinity of the location.  Lets say for the sake of argument that you go to the ideal location, which to me is along the rim of Whipple crater, which itself is on the rim of Peary crater at the lunar north pole.

With a megawatt of power you get a lot for your money.  You can do some serious ISRU of propellants, separating water from the regolith by heating it with solar thermal power (not in the megawatt power budget).  You can then use electrolysis to separate the water into hydrogen and oxygen that can then be used to fuel single stage to orbit cargo and human carriers.  Additionally, you can use the hydrogen and oxygen in closed loop fuel cell vehicles and heavy equipment to do your mining, road building, and other activities.  However, even at the tip of the rim of Whipple crater, the sun does not shine all month, all year around.  There would be periods when you have to power down to a caretaker level.  This does not necessarily have to be bad as it could be the down time needed for maintenance, repair, and roll out of new capabilities.

Over several years some of the power could be used to manufacture solar panels.  Indeed this would be one of the most profitable things to do as if a megawatt is the tipping point of sustainability, then more power, developed locally, creates a lot of leverage.  There is nothing intrinsically impossible about doing this, you just have to send up the right equipment to do so, and then harvest purified silicon from the lunar regolith.  Dr. Alex Ignatiev has a great paper on the subject and has done a lot of work in this area.

Silicon is plentiful on the Moon but it takes a lot of energy to extract it, meaning that as resources are dedicated to this task, fewer resources are available for other activities.  ISRU of metal oxides would be the other major consumer of energy on the Moon and thus the productivity of the outpost is directly proportional to the amount of energy you have and how efficiently you use it.  Adding solar thermal power is straightforward and can be done largely with local resources, providing a multiplier effect for manufacturing.

This path is entirely doable, but is it the best use of financial resources?

Nuclear Power on the Moon

In earlier iterations of lunar architecture studies, such as in the late 1980’s Space Exploration Initiative (SEI), nuclear power was one of the core systems for power at an outpost/base.  This was principally because all of the base ideas that were part of the mainstream were not in the lunar polar regions.  At the time we knew far less about the Moon and its resources than we do now, so this made sense.  The guiding architecture came from a report, called the “Report of the 90 Day Study on Human Exploration of the Moon and Mars“.   This was a very forward looking report at the time that basically had the kitchen sink of technologies, missions, and hardware for exploration built into it.  As one example of how forward looking it was, look on page 3-32 (the link to the document is in the title above) and look at the “Long Range Mars Rover”.  Here it is reproduced as figure 1:

Nuclear Powered Long Range Mars Rover From the SEI Era

Unless you have been living under a rock, you can see that the design of this 1989 Mars rover has a lot of similarity to the Curiosity lander that landed on Mars in August of 2012.  Another advanced feature was a passive nuclear reactor.  This reactor is shown in figure 2:

SEI Era NASA SPT-100, 100 Kilowatt Reactor

In looking at the SPT-100 reactor in the SEI 90 study I am struck by how underpowered the entire outpost would have been.  They were very ambitious in what they wanted to do but 100 kilowatts of nuclear or solar power (there is a solar variant in the study as well), is simply not enough to do a lot of ISRU, exploration and science.  In fairness the ISRU plant was of very modest capabilities and would have been used to make up gasses for the outpost and other non propellant uses.

In the 23 years since the SEI report nuclear technology has advanced fairly rapidly.  Most of it is still in the demonstration or research stage but there are several small nuclear reactors that are on the way to operational status.

Here is the money question….

What could you do on the Moon if you had a 25 megawatt reactor (electrical) and 70 megawatts (thermal) energy.  It changes everything….

Modern Small Nuclear Reactors

There is a pretty good body of information available on the web to inform people about small nuclear power systems.  A very good round up of this information is provided at the   World Nuclear Organization web site.  There are some interesting common attributes of these small nuclear reactors that make them interesting for the Moon.

  1. Small Physical Size
  2. Modular Construction
  3. Unattended or Reduced Manpower Operation.
  4. Self Contained
  5. Low Proliferation Potential
  6. Ease of Disposal
  7. Lots of Power

Rather than go through all of them I selected the one that I thought was a very good representative of the group.  It is by far the smallest in power with only 25 megawatts of electrical output and 70 kilowatts of thermal output but in comparison with what we have been talking about for the Moon up until now it is an amazing advance!

GEN4 Energy Molton Salt Fast Reactor

The GEN4 reactor is an amazing advance over earlier generation small reactors.  Figure 3 shows a conceptual drawing of the reactor system:

The GEN4 25 Megawatt (Electrical) and 70 Megawatt (Thermal) Reactor

Here are the key features of this reactor:

  • Advanced reactor design – Use of advanced reactor concepts provides for a safer and simpler reactor, elimination of many potential accident scenarios that affect LWRs, and elimination of complex reactor systems.
  • Small reactor – A smaller reactor is more appropriately sized for smaller generation requirements, can directly replace existing diesel fueled generators, and requires no upgrade to existing small electricity distribution systems.
  • 10-year power module replacement – The Gen4 Module provides 25 MWe continuously for 10 years on its initial fuel load (compared to an 18 to 24 month cycle for current light water reactors).  No on-site refueling is required.  After 10 years the entire reactor module is replaced.
  • Underground containment vault – The reactor is sited in an underground containment vault to provide isolation from the environment, prevent intrusion or tampering, and avoid harm from natural disasters.
  • Factory-assembled transportable power modules – Factory assembly allows for standard designs, superior quality control, and faster construction and on-site deployment.

All of these features make this reactor amenable for lofting to the Moon for installation.  How much would it cost?  Even if it took ten launches of a Delta IVH or 6 launches of a Falcon 9 heavy, it would be well worth it.  The provision of 25 megawatts of electrical energy and 70 megawatts of thermal energy would transform the proposition of lunar industrialization.

Applications for Massive Power

Gone would be the requirement to engineer every last part of a low power system for optimum efficiency.  This would save quite a bit of money.  The ability to use high power ISRU systems such as vacuum induction melting of metal becomes a no brainer.  With high power ISRU and plentiful metal, structures with large interior volumes becomes very feasible.  Large interior volumes would allow for plentiful living space for humans and operational space for ground systems.  There would be plentiful electrical power and space for growing food, including meat animals.

The thermal energy could be used for the steam reformation of water into hydrogen and oxygen, and do it at an industrial scale, providing fuel for ground based fuel cell vehicles as well as fuel for lunar Single Stage to Orbit (SSTO) cargo transports.  The thermal energy could also be used to drive of the volatiles in the mining of water from the permanently dark areas.  Hot phase change material could also be easily used to keep equipment warm during their sojourns in the dark areas, removing the need for mobile nuclear power systems.

In short, as here on the Earth, power is everything to a civilization and we should very much consider and study, and develop the means whereby to loft these high power systems to the Moon.  It would not be immediately, and for the very near term solar power systems would be used to bootstrap any ground operations on the Moon.  However, the leverage and advantage of these high power, modular, and safe nuclear systems must become central to the industrialization of the Moon.  It would transform the development of Mars as well and would enable the almost immediate colonization of the red planet.

We now have the technology and the tools that we need to open the solar system to development.  We stand at the door.  It would be a hell of a lot better use of money than refilling the corrupt coffers of Wall Street or Brussels.  Indeed it would moot that as the wealth that would come from such development would of itself refill those coffers, and in a far more productive manner….


22 thoughts on “Nuclear Power to the People–On the Moon

  1. I certainly support nuclear power on the Moon.  But my concerns are two-fold.

    First, there is the irrational political concern about launching nuclear material into space.  I’m guessing that the anti-nuclear folk (including some in the the regulatory agencies and administration) might fight as long as they have fought Yucca Mountain to prevent it.

    Secondly, I am concerned that this concept is looking past the first smaller steps to industrializing the Moon and assuming the national will for a program that would conduct multiple launches for large-scale power for a large-scale industrial plant on the Moon.  I don’t believe it likely that we can achieve such consensus.  For example, I’m guessing that we’d have all of our Mars-first friends adamantly opposed to such a “diversion”.

    Finally, I see a viable alternate route at least for the first level of lunar industrial development.  Thin film solar sheets now have the energy density of 1,200 W/kg.  Falcon Heavy, ion propulsion, and an upper stage lunar lander should be able to deliver around 14 tons to the lunar surface.  This would provide up to 16.8 MW for initial industrial operations.  That might be something that a commercial company (concerned with early return-on-investment) might be willing to fund.

    1. Doug

      No where have I advocated going directly to nuclear, I agree it is a bridge too far and it is one of the reasons that I advocate the lunar north pole, you can do solar there and reduce the infrastructure requirements. This is what bootstrapping is all about. However, thin film solar is not good for the Moon. Its radiation resistance is poor, its efficiency is very poor, and its area to power ratio is such that you would need a lot of infrastructure to get the energy out of it that is in its spec.

      I am very much in favor of using advanced quad junction cells that have efficiencies in the mid 35% range and that can be very efficiently packaged. My power lander idea incorporates this concept.

  2. Doug

    I am certainly a fan of bootstrapping. I 100% am in favor in starting out on a small scale, I have always stated this. What this article is about is taking the next step beyond this, or if we are truly serious then it becomes a part of the plan that begins after the solar power system is in place.

    Also, the thin film solar stuff does not work well on the Moon. Thin films degrade rapidly in radiation and you can’t point them at the sun to get the full benefit of the energy.

    1. > I am certainly a fan of bootstrapping. I 100% am in favor in starting out on a small scale, I have always stated this.

      Good. I myself have some fairly detailed ideas about the first step. I believe it possible to jump to a functioning cis-lunar circuit even with a single launch of a Falcon Heavy. We could go more incremental than that but if we could jump to a basic cis-lunar infrastructure for relatively low cost, why not?

      > Thin films degrade rapidly in radiation
      Bummer! Can you refer me to info on that?

        1. Wiki > Hydrogenated amorphous silicon (a-Si:H) has a sufficiently low amount of defects to be used within devices. However, hydrogenation is unfortunately associated with light induced degradation…

          So I see. Then do you know of how much performance we could get with more durable solar panels given 14 ton payloads to the lunar surface?

            1. Can you elaborate a bit on both points? We cannot plan well if we don’t make reasonable assumptions about near-term technologies available. Falcon 9 has successfully launched three times. Falcon Heavy is based upon three F9 cores. SpaceX is spending the money at Vandenberg. True, initial payloads may not be 53 tons to LEO, but 32 tons is reasonable. That still gets us to about 8.5 tons of payload on the lunar surface. A lot can be done with that.

              1. Doug

                As you probably know, I am not a believer in heavy lift. The F9-H is a single source, sole provider vehicle. When they get a lot further along I will pay attention. Until then I design around existing vehicles.

    1. There are illumination maps for both the North and South Pole. From Bussey, et al, it seems that the illumination is not 100% at either pole in their “winter”. Close, but no cigar.

        1. Willam

          You are welcome, sorry for the long delay on the reply. I agree that solar is the best, in terms of lowest total cost, in the near term as a means to bootstrap lunar development.

  3. Dennis, Are you going to be at the AIAA Conference in Pasadena this coming week? If so, I’d like to meet you there. I seem to have missed meeting you at NewSpace 2012.

  4. I am not opposed to a nuclear moon. Especially the use of thorium in a molten fluoride salt reactor. Kirk Sorensen sold me on the idea with his TED talk.

    At the lunar poles though I think solar will be king. The distances from the day side to the night side are short. Solar farms could connect to a power grid for electricity transmission from day side to night side. The power grid will grow down from the North pole and up from the South pole. At some point the transmission distances from the day/night terminator. To the farthest point on the night side. Will become inefficient due to transmission resistances. When you reach this point, having backup thorium reactors will keep the lights on. Space them equally along the the power grid as you approach the equator. Turn them on and off as required by demand.

    Now, this does not answer questions on how to start industrializing the Moon. While I am a fan of Paul Spudis, and you Dennis Wingo, I follow Mark Prado’s PERMANENT initiative. Hoping private organizations will plant the seed and make it grow to an industrialized and colonized Moon.

    With governmental hurdles of launching radioactive materials. I do not see the start of lunar industrialization with nuclear power. High efficiency solar plants launched from Earth could then be used to make fuel from lunar polar water. With fuel from the Moon now used to take payloads from LEO to the lunar surface launch efficiency is increased.

    Bootstrap industry. Use tools to make tools, to make more advanced tools, to make more advanced tools. Till we begin to recreate mining, refining, manufacturing.

    While I agree a nuclear Moon will be needed. I would rather it become nuclear with lunar thorium and uranium. This would be after lunar industry is growing down from the poles backed by solar power.

    Understand, I do not know the details of how it will all happen. Got a 1.3 GPA in High School. A lowly welder/fabricator by trade. However visions of Tsiolkovsky, O’neil, and Ben Bova’s “Welcome to Moonbase” have haunted me since I was 13 in 1988. I want to see it happen in my lifetime.

    1. Understand, I do not know the details of how it will all happen. Got a 1.3 GPA in High School. A lowly welder/fabricator by trade. However visions of Tsiolkovsky, O’neil, and Ben Bova’s “Welcome to Moonbase” have haunted me since I was 13 in 1988. I want to see it happen in my lifetime.

      Welders and fabricators will be the hero’s of lunar industrial development, I work with many and good ones are artists of the highest order.

      As I said earlier in this thread, I 100% agree that we will start with solar. It may even be that we will have to mine lunar Thorium to get the reactor’s fueled. However, we must have them as a low energy density industrial development simply can’t get a lot accomplished for the effort put out. Take a look at the power requirements of a good heavy duty industrial welder and you start to see where I am coming from.

      As 3D printing advances your tools to make tools makes more and more sense.

      Good post…

  5. It seems in the future, that the Moon will a place where a lot energy used and produced.
    The advantage of PV panels would be one can start with small scale operation.
    And due to lack market it seems one has to start at small operation.
    In relation to US government that squanders trillions of dollars, the investment dollars
    needed to kick start lunar operations which eventually lead transforming space is rather minor.

    If the Moon rocket fuel production was 1000 tons rocket fuel if in free market environment-
    meaning there was this much demand and this demand was met, this means falling rocket fuel
    production costs, falling price of rocket fuel and opening the door to the Moon surface and the rest of the solar system. But this does not mean we should start with yearly production of 1000
    tonnes. Within decades thousand of tonnes of rocket made on lunar surface, but we probably should start with tens to hundreds of tonnes year in the beginning.
    Or the investment amount needed for this production should be a few billion dollars as compared to tens or hundreds of billions in start up costs.
    The biggest roadblock to mining the Moon, is the lack of needed exploration that allow this to occur and the lack initial market demand.
    The problem is not the lack money which could be invested, but rather the lack confidence of a return on whatever the investment amount is. And the the lack of immediate market means the more investment dollar spent, lower the possibility of return of those investment dollars.

    Many people think the above is only problem related to the private sector- that government activity is not restrained by these fundamentals. I would say that in theory, this may be true,
    but in practice, such an idea doesn’t work out. In other words, I think government maybe can defy gravity- IF it was rational, but it’s only a maybe and government typically is not rational.

    In addition, government does not lower costs, nor is the government describable as being easily
    accessed- instead it’s mostly a maze of roadblocks of filling paperwork, no one in government able to say, “yes” and has various bias and fighting over turf. Despite any latest campaign to make government more transparent and accessible, one can’t say government ever arrives.

    So, the best view to take is that government, does general follow the same economic “laws” of the private sector. Meaning if invests a lot money into something it requires enough market demand and is more difficult to get in the black- be profitable.

    Now, it seems what government is quite good at, is spending money. So ideas about how use a lot rocket fuel for various things a government might want to do, is probably something a government can manage to do. So idea involving government becoming a significant part of market of buying rocket fuel, could be helpful. Perhaps.

    So what is needed from private sector is building business of supplying rocket fuel. And part of that is customers feeling confident that what is promised can be delivered when the customer wants it. So a customer can plan “things” with some confidence the 10 tons rocket fuel will available when it’s critically needed. And it takes time to “build this business” with past successful operation giving further confidence to potential customers.
    And a government can useful in this regard, as it be a first customer that demonstrates buying rocket fuel is possible.

    So at the moment, there is no market for fuel in space- unless one counts the ISS COTS program as such a market. And in terms NASA, an expansion of this program and perhaps improvement of COTS could the beginning of bigger market of rocket fuel in Space.

    And the other thing NASA needs to do is explore the lunar polar regions to discover whether there is minable deposits of minable lunar water.

    So exploration of Moon, and expansion of COTS, gets us to point where the private sector
    can mine lunar water and make rocket fuel for a small market in space of rocket fuel- and this market size could grow over time.
    So, roughly one might have some market demand over say 5 year with average of 100 tons of lunar rocket fuel made each year.
    And to point of article, a 100 tons of rocket fuel requires around 500,000 kw hours per year, or
    about 57 kW. So 100 kW is probably enough- and 200 kw would more than enough.
    But from year 5 to year 10, one could 10 times as much [or more].
    And as said once production is as high as 1000 tons per year, one transforming the space environment. Rocket fuel on the lunar surface would probably be selling for about $1000 per lb
    which is today’s reference, it’s giving the rocket fuel away for practically free. And of course rocket fuel can become much cheaper than $1000 per lb.
    To get lunar rocket fuel below $100 per lb, you probably need relatively cheap electrical power
    and such things as concentrated source electrical power which you get from Nuclear reactor may give cheaper electrical power.
    But reactor giving 25 MW is too much electrical power is you only have demand of 1000 tons of rocket fuel per year- 2 MW is enough. Of course could be many other thing having higher electrical needs.

    It seems once we at point of 1000 tonnes of rocket fuel and rocket fuel is 1000 per lb or less,
    the moon will be the brink or massive increases in power use and industrialization of all kinds of possibility. With less than 100 tons per year, the moon will be gateway to exploration of rest of solar system. By time we up to 1000 tons per year, exploration of system system will continue, but utilization of rest of solar system is becoming more apparent. So Mars colonization type stuff. But I also would not rule out possible settlement on Mercury- or elsewhere. And the more obvious, utilization of space rocks. Plus such things as improving existing satellite market and such ideas as SPS to provide electrical power to earth may be on the drawing boards as a serious future possibility.
    And initial planning of SPS for earth use may be start with concentrated effort to make lots of solar panels or the Moon or from resources of space rocks brought into Cislunar space.
    Or said differently there may be perception of a large potential future market for solar panels in the entire space environment.
    If your view of future at around this point is a lot settlers heading to Mars or even beyond Mars- say, main asteroid belt. It’s possible the larger market could involve nuclear reactors.

    But regardless, it seems both Nuclear and harvesting solar energy will be main element of energy production in Space environment. But if focus is future SPS for Earth’s energy use, one going to have incentive for vast amount solar panel production in space and at very low unit costs.

  6. One huge power requirement would be the manufacture of fuel – probably Lox and LH2 from dirty water. The more rocket fuel that can be made, the cheaper lunar access becomes, as lunar fuelled craft can do more and more of the Earth to Moon transport.

    However, Dennis states:
    “How much would it cost? Even if it took ten launches of a Delta IVH or 6 launches of a Falcon 9 heavy, it would be well worth it.”

    But what if it took hundreds? Even a small (10s of MW) nuclear reactor weighs hundreds of tons and some components may be hard to break down. It does of course depend on whether a lot of the structure can be made from lunar materials.

    One potential method of solar power would be to build a solar array at the Earth – Moon L1 point and beam the power down. Initially, this could use lasers to beam 100s of KW into vertcially mounted solar receivers. As the scale increases, a rectenna could be built (probably a few hundred km away from the pole) to beam MW and ultimately even GW to the surface.

    1. Alex

      When thinking about this weight most of that is shielding and other bulk materials best derived from local materials. I would also point you in the direction of the compact Thorium reactors that are light enough to be deployed from a truck trailer. I am not really that hip on the whole power beaming thing as it is very complex and the power gain ratio is small over the amount of work that you have to do to get the power.

      Solar is a near term interim means of generating power or for remote outposts without a lot of power requirements…

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