Again, this reactor design is different from an RTG, precisely because it is a reactor. RTGs like those used in the Cassini mission rely on radioactive decay to

Again, this reactor design is different from an RTG, precisely because it is a reactor. RTGs like those used in the Cassini mission rely on radioactive decay to generate heat. They have a significantly smaller power output, on the scale of watts. In Cassini's case, PuO2 fuel was used, and the primary decay mode was alpha decay. These designs are great for long-term, low power missions. https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge... Kilopower will utilize highly-enriched uranium fuel to power a fission reactor. This means that the atoms in the fuel will be sustaining a chain reaction of fissioning, releasing neutrons, causing more atoms to fission, and on and on. This is what generates heat in reactor systems. This design will prove usable for shorter, higher energy demand missions. https://www.nasa.gov/directorates/spacetech/kilopower https://www.nasa.gov/directorates/spacetech/kilopower An RTG is essentially a lump of fuel which sits and decays, generating heat. Kilopower's reactor would be an actual reactor, needing to manage reactivity, burnup, and maintain criticality. They are vastly different systems. For someone not in the field I can see how there'd be some confusion but please be less speculative on topics of which you're less familiar.