Thanks for this to Dan Yurman.... follows his up-to-the-minute tweets about Fukushima at @djysrv

Unit 1(Shut down)


- Reactor has been shut down. However, the unit is under inspection due
 to the explosive sound and white smoke that was confirmed after the big
 quake occurred at 3:36PM.
- We have been injecting sea water and boric acid which absorbs neutron
 into the reactor pressure vessel.

Unit 2(Shut down)
- Reactor has been shut down and Reactor Core Isolation Cooling System
 has been injecting water to the reactor. Current reactor water level is
 lower than normal level, but the water level is steady. After fully
 securing safety, measures to lowering the pressure of reactor
 containment vessel has been taken, under the instruction of
 the national government.

Unit 3(Shut down)
- Reactor has been shut down. However, as High Pressure Core Injection
 System has been automatically shut down and water injection to
 the reactor was interrupted, following the instruction by
 the government and with fully securing safety, steps to lowering
 the pressure of reactor containment vessel has been taken. Spraying
 in order to lower pressure level within the reactor containment vessel
 has been cancelled.
- After that, safety relief valve has been opened manually, lowering
 the pressure level of the reactor, which was immediately followed
 by injection of boric acid water which absorbs neutron, into
 the reactor pressure vessel.

Unit 4 (shut down due to regular inspection)
- Reactor has been shut down and sufficient level of reactor coolant
 to ensure safety is maintained.
- Currently, we do not believe there is any reactor coolant leakage
 inside the reactor containment vessel.

Unit 5 (outage due to regular inspection)
- Reactor has been shut down and sufficient level of reactor coolant
 to ensure safety is maintained.
- Currently, we do not believe there is any reactor coolant leakage
 inside the reactor containment vessel.

Unit 6 (outage due to regular inspection)
- Reactor has been shut down and sufficient level of reactor coolant
 to ensure safety is maintained.
- Currently, we do not believe there is any reactor coolant leakage
 inside the reactor containment vessel.