It’s better to provide electricity than to blow people up.

U-235 and Plutonium can be used in generators to make electric power. You reticulate the material atom by atom on graphene tape and feed it into a nozzle along with reaction mass (water, works but in outer space lead is also ok). You provide slow neutrons by mashing Beryllium and Polonium together. The nozzle must contain alloy elements that keep it strong under high heat. You need manganese, nickel, molybdenum steel.