If Transportation Secretary and acting NASA Administrator Sean Duffy wanted to do his part to help provide a distraction from the Trump administration’s Jeffrey Epstein files scandal, his announcement of a plan to put nuclear reactors on the moon was a partial success. In the 24 hours after his announcement on Monday, he was briefly trending on social media, just behind Ghislaine Maxwell.
If he intended this to be a serious proposal for human occupation of the moon, he failed. For the near future, nuclear reactors on the moon are impractical, expensive and dangerous.
Duffy may not understand this. He has no experience in space or nuclear technology. He is a former Fox News host who became interim director in June when President Donald Trump pulled the nomination of Elon Musk’s choice, billionaire Jared Isaacman, after Trump’s breakup with Musk.
For the near future, nuclear reactors on the moon are impractical, expensive and dangerous.
Space exploration has used nuclear materials for power for many decades. This is overwhelmingly in the form of radioisotope thermoelectric generators. These use plutonium-238, which gives off heat used to generate electric power for small probes, including some of the rovers on Mars. This typically involves 20 or 30 pounds of material. In fact, several of the Apollo missions left some behind on the moon were powered by such radioactive means.
But a nuclear reactor is another matter altogether. This would involve potentially hundreds of pounds of low-enriched uranium in yet-undeveloped small reactors delivered by space launchers that don’t exist.
NASA officials have been planning for small modular reactors for the moon and Mars for years.
As CNBC explained in 2020: “The facility will be fully manufactured and assembled on Earth, then tested for safety and to make sure it operates correctly. Afterwards, it will be integrated with a lunar lander, and a launch vehicle will transport it to an orbit around the moon. A lander will lower it to the surface, and once it arrives, it will be ready for operation with no additional assembly or construction required.”
NASA has made some progress. But now Duffy wants to accelerate the plans to leap from the 10-kilowatt reactor (quite small by power standards) to the 100kW reactor — and launch it by 2030. This would be five years ahead of the announced plans of Russia and China for similar missions.
There is a little chance that he can do it. This new timeline is actually four years later than the 2026 target of a “flight system, lander and reactor” that NASA set just five years ago. None of these exist today.
The cost of doing all this isn’t mentioned in any of his news releases. But it’s likely to be billions of dollars more in contracts to corporations such as Boeing and Lockheed Martin and newly formed energy companies. Where will the money come from? Perhaps from the freed-up budgets of some of the 41 space missions NASA canceled in May as part of Trump’s vicious 47% cut in NASA’s budget — including several spacecraft already paid for, launched and making discoveries.
“These spacecraft are designed to track the major forces shaping our planet, from rainfall and wildfires to hurricanes and urbanization,” writes Asa Stahl, science editor at the Planetary Society. “People all over the world use this information to help keep crops alive and stave off natural disasters.” They now take a back seat to crewed moon missions.
What could go wrong? The most obvious disaster scenario is an explosion upon launch. NASA takes great care to plot the launch trajectories of missions using nuclear materials so that if there is an accident, the small quantities of radioactive material would scatter over less-populated areas. Launching a nuclear reactor is significantly more dangerous.
It isn’t obvious that nuclear power on the moon is necessary at all. In 1977, the Soviet Union launched a satellite with a nuclear reactor into low-Earth orbit. Within weeks, the satellite failed. The safety backup plan to eject the reactor into outer space also failed. The satellite, with over 100 pounds of weapons-grade uranium, plunged into the Earth’s atmosphere, burning up and scattering radioactive debris over a 400-mile path in Canada. The cleanup took eight months. Nor is it clear that private corporations would be as careful. There are already major complaints about the debris falling from the many failed SpaceX launches. Radioactive debris would be much more serious. Another lunar nuclear nightmare would be an explosion on the moon’s surface. If, say, a meteorite hit the reactor’s cooling system, heat could build up, triggering an explosion that could contaminate a large area of the moon and cut off any base from its power supply. Fortunately, it isn’t obvious that nuclear power on the moon is necessary at all. It is at least as likely that we could develop improved batteries to store solar energy. These could power small bases during the two-week-long lunar nights. Many of the rovers and probes that use thermoelectric sources for heat and energy rely primarily on solar panels for their power. In the 1950s, nuclear power proponents promised in congressional hearings that nuclear power would soon make electricity so cheap that we wouldn’t have to meter it. We would soon have nuclear-powered airplanes and cars and small reactors for every home. Seventy years later, none of these predicted benefits have appeared. Nuclear proponents are undeterred. Propelled by the prospect of huge profits from government contracts, they are just as enthusiastic today. Small, safe, launch-ready nuclear reactors, it seems, will always be just around the corner. Duffy’s ploy worked for about one news cycle, generating headlines and visions of a new nuclear space race, but it did little to change technological realities. Atomic-powered space colonies are likely to remain a nuclear pie in the sky for the foreseeable future.
Joseph Cirincione
Joseph Cirincione is the vice chair of the Center for International Policy Board of Directors. 
