Originally Posted By: UTAlumnus
I never have understood this.
1. Why not put a transformer on site & use the power from the turbines to run the cooling pumps?
2. Control the damping rods with an electromagnet connection. If the pumps are out of power long enough for the electromagnets to lose charge, the rods drop.

I'm a bit hazy on the details of nuclear power plant specs, but I believe that the Fukushima reactors do/did have passive (and pump-less) means to cool the reactors even without power, but I believe that they all failed eventually. Unit 1 had something called an isolation condenser (IC). Unit 4's is called a reactor core isolation condenser (RCIC). Not sure about Units 2 and 3. I don't know if they would be able to cool the reactors enough all by themselves all the way to cold shutdown or whether they are just stop gap measures.

As for #2, I suspect that the practicalities of needing room to periodically load/unload fuel rods from the top of the reactor vessel is why the control rods come up from the bottom.