Status of Fukushima nuclear power plants Tuesday night

The following is the known status as of Tuesday night of each of the six reactors at the Fukushima Daiichi nuclear power plant and the four reactors at the Fukushima Daini plant, both in Fukushima Prefecture, which were crippled by the magnitude 9.0 earthquake and ensuing tsunami on March 11.

Fukushima Daiichi plant

-- Reactor No. 1 (Operation suspended after quake)

Partial melting of core, cooling failure, vapor vented, building housing containment of reactor damaged by hydrogen explosion, roof blown off, seawater being pumped in, work to restore electric power in progress.

-- Reactor No. 2 (Operation suspended after quake)

Damage to reactor containment structure feared, cooling failure, seawater being pumped in, fuel rods fully exposed temporarily, vapor vented, building housing containment of reactor damaged by blast at adjacent reactor No. 3, blast heard near suppression chamber of containment vessel, access to external power restored Sunday, steam seen rising Monday, pool holding spent-fuel rods filled with water on Tuesday with water temperature at 51 C.

-- Reactor No. 3 (Operation suspended after quake)

Partial melting of core feared, cooling failure, vapor vented, seawater being pumped in, building housing containment of reactor badly damaged by hydrogen explosion, seawater dumped over spent-fuel storage pool by helicopter Thursday, water sprayed at it from the ground for six days through Tuesday, workers temporarily forced to evacuate due to grayish smoke seen billowing from roof on Monday, lighting back on in control room on Tuesday.

-- Reactor No. 4 (Under maintenance when quake struck)

No fuel rods in reactor core, renewed nuclear chain reaction feared at spent-fuel storage pool, fire at building housing containment of reactor, only frame remains of reactor building roof, temperature in the pool reached 84 C on March 14, water sprayed at pool for three days through Tuesday.

-- Reactor No. 5 (Under maintenance when quake struck)

Some fuel rods left in reactor core, cooling in spent-fuel storage pool resumed Saturday, cold shutdown at reactor on Sunday, access to external power restored, power source switched to external power from emergency power on Monday.

-- Reactor No. 6 (Under maintenance when quake struck)

Some fuel rods left in reactor core, emergency power generator and cooling functions restored Saturday, cold shutdown at reactor on Sunday.

Fukushima Daini plant

-- Reactors No. 1, 2, 3, 4 (Operation suspended after quake)

Cold shutdown, not under emergency status.
Kyodo