Over at the WSJ shortly after this thing started, I posted a benign comment using my real name explaining that Nuclear Plants don’t run using their own generated power – that they are reliant on outside power to operate, or diesel power backups, and if the backups had failed, this was going to be a serious problem and grow bigger. I was immediately pounced on as not knowing anything about nuclear power and being s fear monger.
So they now have a power cable running a long distance of 1.4 km (roughly one mile) that took a week to decide to install – keep in mind this is the power company and they know how to run power cables. Admittedly, they have a lot of plates spinning, but this one made its dangers known pretty early on.
This is confirming my earlier belief / suspicion – that the problem has less to do with the generators but that the power distribution area was flooded. You can’t reconnect a power source to a bunch of cables that have been sitting in a puddle of salt water. Even when you pump out the salt water, much of what is in there is damaged or at a minimum can’t be used until it is tested.
So under the constant deluge of radiation, they’ve been cobbling up temporary power distribution boards and connecting things up one at a time as they are fairly sure they won’t short out or otherwise do bad things. A nuclear power plant isn’t like the distributor cap on your ’57 chevy. About all they’re going to wire in is possibly the circulator pumps… probably some other general purpose pumps to spray water around. and bring in lead shielding to get people near the reactors a place to reduce radiation dosage when they are waiting for something or there is a sudden spike expected due to a necessary steam release.
As for whether a nuclear plant needs off-site power to run, it really depends on what part of the world the plant is located. In the U.S. we have a very stable electrical grid (compared to the rest of the world) and our plants use grid power for the main pumping systems even while they are producing power and sending it out to the grid. This keeps all those pumps online if the reactor scrams. In other nations the grid is not as stable and it may make more sense to power the main pumps internally from the plant turbine generator, because if the reactor scrams the local grid is going down with it. Florida used to be in this situation- due to the state having only a few key electrical connections with the continental grid, the loss of a couple of key power plants during the summer A/C season could bring down most of the grid statewide.
But you’re absolutely right about the power situation after a scram. Nuclear plants need grid power (or something) to keep the emergency systems running. Three of the Duke Power reactors have a dedicated hydroelectric station (Keowee hydro) that’s used for backup emergency power if the diesel generators fail or run out of fuel. That’s a pretty neat setup.
I have a moderately clear memory of being told that Duke made sure that it had duel paths to the grid. Even without a problem at the plant, if the path to the grid goes down and you gets disperse the energy, that forces the shutdown. Marshall Steam station is right down the road from McGuire, and the Cowan Fords dam has hydro power nearby that can turn on immediately if needed, but the plant still had diesel backup generators.
Then again, Duke Power was run at the time by a man named Bill Lee – an engineer, not an Investment Banker or a government discard.