As part of its plan to establish a permanent human presence on the Moon, NASA is developing a small nuclear reactor that could provide continuous power for future lunar bases, research stations, and long-term missions.
The Moon experiences nights that last about 14 Earth days, during which solar panels cannot generate electricity, making nuclear energy a reliable alternative. This is not the first time nuclear technology has been used in space. In 1965, SNAP-10A became the first nuclear-powered satellite, operating in Earth orbit for 43 days. Since then, nuclear systems have powered deep-space missions such as Voyager and the Mars rover Curiosity, allowing spacecraft to function far from the Sun where solar energy is limited.
The new Kilopower reactor design is compact but capable of supplying enough electricity to support a small lunar outpost for up to a decade. However, one important question remains: what would happen if the reactor experienced a meltdown on the Moon? Unlike Earth, the Moon has no atmosphere, no wind, and much weaker gravity, so a nuclear accident would look very different.
There would likely be no massive explosion or mushroom cloud, because those effects depend on interactions with air. Instead, the reactor could overheat and melt, forming a glowing pool of molten metal that would eventually cool and solidify in place. Radiation would still be present and dangerous to anyone nearby, but without air to carry radioactive particles, the contamination would remain localized around the reactor site rather than spreading across large distances.
Importantly, modern Kilopower reactors are designed with strong safety features, including passive cooling systems, low-enrichment uranium, and automatic shutdown mechanisms, making a catastrophic failure extremely unlikely. As a result, nuclear reactors on the Moon could become a critical power source for future lunar settlements, helping humanity build a permanent foothold beyond Earth and opening the door to deeper exploration of the solar system.
Source: BBC science magazine
