Jay put up a comment with a number of interesting ideas and questions. I’ll give my take on a few.
I’m curious if automatic scram of all reactors after a quake is the standard response plan everywhere.
It is and would have always been, even without Fukushima. Remember these safety plans are theoretical models. It doesn’t matter if components are rated “earthquake proof” if we can’t demonstrate the entire interrelated system is proof. And, short of an earthquake, we can’t.
No executive would entertain a scenario that might end with him in front of an inquiry board, with a “dumb as a styrofoam gas tank” Senator leaning forward and asking, “Son, at what point did yew realize that runnin’ a nuke-u-ler plant in an earthquake was a mistake?”
I imagine Japan is much the same. If there’s any flexibility, I’d guess it’s in the name. At what level are you allowed to switch from “earthquake” to “seismic activity”? That’s the Public Relations Threshold (which I just made up but am pretty sure is right).
…if the reactors were intact after the quake they could have left one running to provide power for a controlled shutdown of the others.
That would require permission to keep running a nuke during an earthquake, which was never going to happen. And running “jumper cables” from one to another seems an engineering and financial nightmare. These plants produce a billion watts of power. It doesn’t just get tossed on the grid, there’s a lot of electrical infrastructure. I don’t know how much of that you’d have to duplicate for the jumper cables, but I’m guessing somewhere between $$$$$$$ and $$$$$$$$$$$$.
Rather than that, they’d opt for another backup layer. Or, see below.
My guess is a reactor with intact containment is a heck of lot more tsunami resistant than diesel gens (and their fuel).
You are absolutely right. But again, “running a nuke during an earthquake” was never gonna fly in the p.r. world.
I’m so, so rusty on commercial nukes. But I think (correct me if I’m wrong, readers) aren’t some systems designed to run emergency vented steam across the turbine? That’s really elegant emergency engineering. You’re playing your problem against itself. You’ve lost electricity, so the core’s overheating. Thus you’re getting unwanted steam. Well then, shunt it to the turbine and now you have power for the coolant systems.
Maybe we should consider having older plants vulnerable to loss of power emergencies install a smaller modular reactor with passive cooling to run the bigger reactors.
That seems a bit kludge-like. And there will be no extensive and expensive retrofits of BWRs and PWRs. Most of these plants are deep into their planned lifetimes; some have gotten extensions. And now comes this.
Once these nuclear geezers are phased out we’ll either go nuke-free or go with “passively safe” designs as you mentioned. And your idea of siting the new ones at old nuke sites? I like it! It seems extremely promising to me.
To me the most terrible design feature was placing their electrical “backup/backup” (and possibly the “b/b/b”) where it (they) was vulnerable to the same thing as the “backup”
And thanks for the thoughful comments, Jay.