"spent" fule reactors?

[142857]

I'm no nuclear expert...far from it in fact. But, I have been thinking about it, I could be way way off base but consider this and tell me why not?

A nuclear reactors spent fule stays hot for hundreds/thousands of years?
Is there no possible way to use these spent rods within a secondary/different kind of power plant?
So you remove the spent rods from your reactor and load them into another kind of generator and make Ele with them for the duration of their storage.

Seems like it would take a much simpler, almost passive kind of power plant. Even if it wasn't that efficient it still makes more sense than dry casting it and getting nothing from it, for however long that's gonna last anyway.

So I guess, what I really asking is:

Would it be possible to build a giant sort of battery-ish-thing, that we could shovel radioactive waste into as fuel ?

An endlessly hot coal inside a tin can is a potential power source...so I must be misunderstanding the properties of the waste it's self?

[dutchdivco]

I'm no expert either

So, if they are still generating heat, what about them is 'spent'? Why take them out of the reactor in the first place.
I think maybe the answer is that nuclear reactor is a controlled nuclear reaction.Maybe the spent rods change to the point that they are no longer putting out a set steady and consistent amount of radioactivity and or heat, so you can't place them in a set amount of proximity to each other, and control the reaction.
Just a guess.France is the only country that has come up with a way to re-process the spent fuel, from what I've read; they make it into plutonium.
Kind of like the original designed purpose for heroin; it was intended to be used to treat people who had become addicted to opium and morphine.OOps! Jim

[quantumuppercut]

The reactor fuel is like a battery. When the battery is used up, we trash them. Some good amount of usable energy still left though, however, the power is not that great. In a way, you're right about we can still get energy out of it (like a joule thief).