@Jordan_W_Taylor
Kilopower, the little Martian reactor that could: A miracle of simplicity & sodium. NASA was given the brief to design a super-simple micro-reactor for future Martian settlement, and it did so brilliantly by doing it unconventionally. A normal Earthbound nuclear reactor is complex, with banks of pumps, water & steam injection pressurizers, control rod actuation, frequent movement of fuel during refuelling cycles, complex systems of valves, back-up emergency coolant and deluge systems, boron injection… it goes on & on & on. A terrestrial nuclear plant is a triumph of safety-conscious system engineering, but it’s a busy one, and Kilopower dispensed with all of this. The intention for the system is that you could set it up, get it started and just… forget about it, pretty much. It has a small, solid core with no moving pieces except for the control rod which is designed to be moved on startup and then kept in place, unmonitored, for a decade at a time. The small size & low power means that reactivity effects are dominated by thermal expansion and are extremely stable. Low power designs (less than 100 kiloWatts thermal energy) make thermal management and irradiation damage a non-issue that does not complicate system design. Very low power level designs (less than 10kW thermal) feature such low burnup reactivity that movement of the control rod becomes a ten-year interval. A literal ‘tin’ wedding anniversary, marked out by tweaks to the control rod. There’s a quirky Martian anniversary gift for you! Even at much higher power levels, the stability is such, and burnup so low, that control rod movement would be something you’d only have to do occasionally, every few months or annually. In essence this is a nuclear battery. In all cases, the reactor is designed to handle worst-case transients such as coolant loss passively without any need for control inputs, further simplifying the system. Truly, this is a zen ideal: Feng Shui engineering, where less is more and the system simplicity brings reliability and safety, all in one. Perfect for missions to space.
