Good comment! After the earthquake (not tsunami) caused the cooling failures at Fukushima's Daiichi plant (supposedly) "spent" fuel rods (stored in cooling ponds above the reactors) reached red hot, then white hot (then vaporising) over a matter of hours ...as did the exploded fragments of reactor rods. If spent rods can generate so much heat then it is clear that they could generate steam for turbines.

Perhaps there is much more emitted thermal energy from newer reactor rods, resisting cooling (for steam generation) than spent ones ...but I take your point that we may have been slipped a less than truthful version of things?