|Since spent fuel rods from propulsion reactors are still quite hot would it be possible to harness the heat produced for energy needs? It seems like a possible source, and a waste not to harness what we can. — SS, Lakewood, CO
While the radioactive decays from spent nuclear fuel rods continue to produce thermal energy, the amount of energy released each second isn't enough to make it cost effective to use that energy. Since the power output from a spent fuel rod would only be in the watt range, it wouldn't justify the hazardous job of trying to extract that power without encountering the radiation. Furthermore, the laws of thermodynamics make it much harder to use heat from a warm object than heat from a hot object and spent fuel rods would at best be warm objects.