Exactly! This is one of the worst case scenarios for a nuclear power plant. In most of these plants there is a single steam pipe, a couple of feet in diameter, that carries roughly a HUNDRED MILLION horsepower of steam power. That energy has to go somewhere. If it can't make electricity, it makes heat.....lots of heat. If the plant loses the grid, back up generators the size of two locomotives must start within 30 seconds to provide pumps to move the heat away, and shut down the reactor. If not, you have a core meltdown.
The Chernobyl disaster was started by a hare brained idea from the operators that they could shut down the reactor without using back up generators, by using the power from its own nuclear powered generators. The plant ran out of electricity, before it ran out of heat, and viola! - meltdown. Modern reactors don't have the fires that caused all of the Chernobyl aftermath, but they still can have the core meltdown.
If the plant loses the grid, back up generators the size of two locomotives must start within 30 seconds to provide pumps to move the heat away, and shut down the reactor. If not, you have a core meltdown.
Not quite as dire as that, but you are on the right track. As long as they don’t lose the ability to operate valving as they did at Fukushima there are further resources to bring to bear to maintain control over the plant.
When you have to try and connect your Sears portable compressor and run it from an inverter using the car batteries you scavenged from your co-workers cars in the parking lot to operate the plant’s valves, at that point I think you are well and truly screwed. ( Fukushima )
Except of course it isn't. The OPAL (Open Pool Australian Light-water) Reactor is a 20 Megawatt (thermal) research reactor used primarily for isotope production not electricity production (no steam generators). In the event that the fire threatens the power grid, the reactor will be safely shut down (if not already shut down) and Diesel generators will start and provide backup power. Even if that fails, the open pool design should be capable of providing adequate decay heat removal via evaporation for several days. By that time decay heat will be significantly reduced, and other methods can be put in place to ensure cooling.
“In most of these plants there is a single steam pipe, a couple of feet in diameter, that carries roughly a HUNDRED MILLION horsepower of steam power. “
Amazing statistic. I want to work out the HP equivalent for our (my state’s although it is federal) Grand Coulee Dam.
“HUNDRED MILLION horsepower of steam power”
Second reply: They should harness that to do some real work! /s
prayers for Sydney area, I have visited.