👉 In physics, a refire is a process in which a fuel or an oxidizer is re-activated to form new fuel. This can be done by heating it up, or by using some other means of activation. Refiring is often used in nuclear reactors for generating new energy from the spent fuel stored there. Refires are important because they allow the reactor to continue operating, even when fuel has been depleted. The refire process can also be used to remove radioactive materials from the reactor,