I 've red yesterday that they use fire engines to pump the seawater into the reactor.
We have to figure how tricky - if not desperate - the actual situation is (feel free to correct me if I'm wrong, I'll erase this post then)
The Japanese need, quite simply, water to be pumped int the reactor to cool it. Right. The real problem, however, is: we have pumps, but what energy source to make them work ?
- the power grid has been knocked down
- the oil infrastructure has been knocked down
- the powerplant emergency systems have been knocked down.
No fuel, no electricity on the site: perhaps that explain why they had to resort to the fire engines as makeshift nuclear powerplant cooling systems.
A fire engines is somewhat autonomous - power-wise, fuel-wise, pump-wise, it doesn't depend from external sources. It can run on its own engine, fuel, batteries... at least for a short time !
Then at some point the fire engine will exhaust its fuel supply. Then how do you refuel the truck, since power, fuel, electricity grids are devastated ?