It seems to me, a non-expert, that they have at least two reactors (out of six reporting major problems after the quake and tsunami) in meltdown (uncontrolled fission) and undergoing 'dirty' fission processes. This means that dumping seawater on them isn't going to cool them (water could actually increase reaction of U-235 because it slows emitted neutrons and helps U-235 to capture them, causing more fission).
It seem that they are simply hoping that the containment underneath holds while they spray sea water on the cores and work to restore power to buildings and pump systems that are largely destroyed and inoperable.
That is to say, they have no other plan that they want to discuss publicly.
If radioactive contamination continues to worsen, at best, they have about a week from today to come out with something that looks like a plan to solve the issues, or they are going to have major panic in the Kanto area, with 35 million people.
Things in Japan are not going well at all.