Quote:
Originally Posted by goo3
(Post 7380696)
Hey, does anyone know why they weren't able to bring in portable generators? I read that they tried but failed. Was this (and associated testing) officially part of their backup plans or not?
If feasible, this seems like a good contingency for on-site failure that's also not site-specific, meaning they can truck these in from a safe location to anywhere that needs them.
Knowing cooling was so critical to the safety of the plant, I just find it hard to believe there would only be 2 layers of backup power (diesel generators and battery) in case of a shutdown. There must have been more of a contingency built-in. |
Their contingency plan was the equivalent of having your house built out of fireproof materials, 2 firetrucks in the driveway, and 12 hydrants placed in a circular formation around your house with firemen keeping watch 24hr a day in case something should happen. Unfortunately, a once in a thousand year flaming meteor lands on your house, destroys the trucks and hydrants, and your house goes up in a ball of flames. I guess you could have had a better contingency plan, but it probably wouldn't have made a lot of sense.
The first thing the earthquake did was cut off all external power to the plant. This meant, the plant was standalone from that point forward. Secondly, because the reactors were immediately and automatically shut down, the plant couldn't produce any power on site either. So from the second the earthquake struck, the plant was entirely reliant on its backup power sources.
The tsunami wiped out the first line of backups (the diesel generators) about an hour later. Of course, no one could have predicted the size and power of this particular tsunami. They generally don't engineer things for events that might occur once every 1000 years or so (and truthfully it doesn't make sense to do so).
Then they had approx. 8 hours of battery backup generators before things really started going awry.
As I understand it, there are a number of independent cooling systems to account for these things, as the last thing anyone wants is a meltdown.
We still don't know (because the company hasn't released the info) which of these systems failed and why.
They did bring in spare generators. Keep in mind this isn't like wheeling in a 5hp B&S generator from Home Depot and hooking it up to a garden hose. Its a pretty serious ordeal.
They managed to restore some of the power to the cooling systems with the portable generators; in the meantime, explosions were rocking the place, and workers were being evacuated at times due to high levels of radioactivity. Also they were fighting a losing battle at times, because the water in was less than the water out, which was leaving rods apparently exposed and damaging the cooling systems further.
Its not like the cooling systems were all perfectly working, and they just needed a way to be powered. The whole systems were thrashed by the tsunami, explosions, etc. Again, we don't know the specific details yet.
At the end of the day, it was a catastrophic wave that no one was prepared for. The plant was prepared to withstand a 20ft high tsunami without problems. What hit the plant was something much closer to 50ft. When your generators are now at the bottom of a swimming pool, its not so easy to swap them out I imagine.
One of the biggest issues was getting resources to the facility to help as well. The whole area was ravaged and flooded. Roads were blocked, people were dead, the country was as panicked as one can get.
仕方がない