Bad situation
The perfect storm of a massive earthquake followed by a massive tsunami was bad enough to overwhelm the emergency systems in the reactors. The design of the Japanese reactors was probably considered to be excellent before the earthquake.
From what I have read, some of the emergency systems failed completely including the backup diesel powered generator. It is unfortunate that several nuclear sites are in an emergency situation at the same time. That sea water is being used to cool the fuel rods shows how desparate the situation is.
The failures and problems with these reactors should provide good analysis of the cooling and emergency systems for reactors. My guess is that this will only slow down the construction of new reactors like the gulf oil spill only slowed down the deep water drilling. The global energy needs are greater than technology can provide and energy costs are going to increase.
