Neutron Propulsion

My big idea this morning is to use radioactive materials for propulsion for interstellar probes. (some?) Radioactive materials produce high velocity neutrons. Put your radioactive material in a heavy pot. Point the opening in the pot opposite the way you want to go. Thrust would be very low, but very long lasting. Don't need to worry about radiation, space is full of it. Just need heavy shielding in the pot to protect the rest of the spacecraft.