no one uses californium for start up reactor
Add a liquid element with high surface tension, so it forms into ball you can fly with by dumping powders on
HICE deuterium ice .solid deuterium has high life explodes in contact with protons neutrons bounce off but melt peices of it
In real life, it's used to start nuclear reactors.
Add Californium, it's a super cool super expensive element that decays extremely quickly in vast amounts of neutrons. The thing would decay in neutrons even faster than plutonium, under any pressure or temperature, without exploding, so no shockwave. However, it can get very hot while decaying.
Add helium, and nitrogen gas to replace noble gas. also add sodium (silver thing that explodes on contact with water) and chlorine (toxic green gas) to make salt
your mom (yrmm) a stickman but is fat asfck