August 24, 2023

After Vikram, Bhabha next : Nuclear Power on the Moon

The stunning success of the Chandrayaan / Vikram / Pragyan mission opens up a world of possibilities for India on the Moon. The next logical step would be to set up a permanent base station - similar to Dakshin Gangotri in Antartica -- that would serve as a locus for the mining, manufacturing and other operations. The Indian engineering industry has extensive experience in these areas, but their expertise would have to be fine-tuned and optimised for the lunar environment. The single most significant difference from Earth bound operations would be the use of autonomous machines, or robots, to do most, if not all of the work. This is because supporting a human workforce in such a harsh environment would increase the cost of doing business to the point of becoming economically non-sustainable.

But irrespective of what we mine, manufacture or otherwise process on an industrial scale on the Moon, what we would need first is a source of energy - abundant energy. While solar panels that trap solar energy and generate electricity are good for scientific experimentation and proof-of-concept development, they hardly generate enough power to sustain -- especially through the long lunar night -- a full-scale industrial civilisation, which is what we should obviously aim for on the Moon.  After all, India has not invested in ISRO and space technology just to flaunt its technical acumen. Trade and industry must follow the tricolour flag that Vikram has placed on the Moon.

Fossil fuels are again out of the question because even in the extremely unlikely event of locating deposits, there is no oxygen on the Moon to burn them and generate heat. So, the only realistic option for generating electricity on an industrial scale is nuclear energy. In fact, this is true even for Earth but because we have easier options here, we do not explore it so urgently. But on the Moon, nuclear energy is the only option and fortunately, setting up small, nuclear plants on the Moon is -- relatively speaking -- not at all that difficult.

Small modular reactors (SMR) [see 12] are the first choice in this regard because of two important reasons. First, they need a smaller amount of radioactive fuel and second, and more importantly, they can be built at a remote factory and then carried to and installed at the intended site. This is the perfect approach for a lunar power plant because we could build these reactors on Earth and carry them, in multiple, and bigger, Chandrayaan type missions to the surface of the Moon and have them installed by autonomous robotic workers.

Nuclear power on Earth faces political and environmental challenges because it is perceived to be dangerous for humans, even though a rational debate would debunk this claim. On the Moon however, this would not be an issue at all because there is, literally, enough space out there to make sure that reactors and the spent fuel are located far away from the base station. In fact, new nuclear technology can in fact be first tried out, first on the safety of the Moon before they are deployed back here on Earth. Isaac Asimov had indeed anticipated this in his sci-fi micro-story "Silly Asses".

Ferrying a small modular reactor from Earth to the Moon in a knocked-down state is again not a difficult proposition. A 300 MW nuclear reactor of the kind used in nuclear submarines would weight around 700 tons. Assuming that an enhanced Chandrayaan can carry a 10 ton payload on an energy-frugal journey to the moon, we would need 70 launches. A Chandrayaan mission costs around Rs 650 crores and of course this cost will go down significantly with each subsequent and successful mission. A typical wide-bodied aircraft from Airbus or Boeing costs around Rs 400 crores and both Air India and Indigo have placed orders for hundreds, yes hundreds, of these machines. So the Indian economy could easily sustain two Chandrayaan launches every month and create resilient supply chain that will deliver a small modular reactor to the Moon in a reasonable, 5 - 7 year, time frame.

Finally, where we do get these small modular reactors from? The Indian atomic energy program is currently focussed on building and commissioning large nuclear power plants in different parts of the country and even this has run into political and environmental challenges. However, SMR technology is under active development in many countries and some plants have already been commissioned in Russia and China. What we would need to do is to leverage our extensive experience in traditional nuclear power and quickly set up industrial alliances with suppliers of SMR technology to create new models and designs for SMRs that can be deployed on the Moon.

This approach would call for both the Indian Space Research Organisation and the Indian Atomic Energy Commission -- two very powerful and autonomous bodies -- to work together towards the common goal of creating a sustainable energy supply for a vibrant industrial economy on the Moon. This can only happen if the political leadership takes the initiative to initiate such a mega project and drive it to its successful conclusion.

After Vikram (Sarabhai) it is time for (Homi) Bhabha to go to the Moon.

Post Script : Two of my engineer friends, Amitava Das and Rob Roy have indicated that heat removal may be a big challenge on the Moon. I am sure that this is not the only challenge but I am also sure that all such challenges can surely be overcome.


The reader may also look at three earlier posts on the contours of the space economy