Will it weigh more than a Tesla?
The leading contender for Project Pele is the Radiant mobile reactor that is being developed by Elon Musk’s SpaceX engineers. It is a High Temperature Gas (HTG) pebble bed reactor design that uses solid TRISO High Assay Low Enrichment Uranium (HALEU) fuel balls. This means the reactor can never melt down with a loss of coolant because the fuel expands as it gets hotter and eventually loses criticality (called negative temperature coefficient) automatically shutting it down.
All the waste products are sealed in the pebbles which burn Uranium 235 for a few years until they need to be replaced using a fully robotic process that doesn’t need to open the core. If the helium coolant leaks it is not radioactive and can’t cause steam or hydrogen explosions like Fukushima or Chernobyl water cooled reactors.
It could be trucked to a site and parked under a concrete or earthen revetment as further protection from most ordinance. If the government builds enough of them, Tesla may want to build commercial versions, sell the electricity to the grid, and rebate Tesla owners for all or part of their electric consumption. If the electricity is almost free, I might even buy one.