TOKYO, March 19, Kyodo
The following is the known status as of Friday 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 the ensuing tsunami on March 11.
Fukushima Daiichi plant
-- Reactor No. 1 - Operation suspended after quake, cooling failure, partial melting of core, vapor vented, building housing reactor damaged March 12 by hydrogen explosion, roof blown off, seawater being pumped in.
-- Reactor No. 2 - Operation suspended after quake, cooling failure, seawater being pumped in, fuel rods fully exposed temporarily, vapor vented, building housing reactor damaged Monday by blast at reactor No. 3, blast sound heard near suppression chamber of containment vessel on Tuesday, damage to containment structure feared.
-- Reactor No. 3 - Operation suspended after quake, cooling failure, partial melting of core feared, vapor vented, seawater being pumped in, building housing reactor badly damaged Monday by hydrogen explosion, high-level radiation measured nearby on Tuesday, plume of smoke observed Wednesday and presumed to have come from spent-fuel storage pool, seawater dumped over pool by helicopter on Thursday, water sprayed at it from ground on Thursday and Friday.
-- Reactor No. 4 - Under maintenance when quake struck, no fuel rods in reactor core, temperature in spent-fuel storage pool reached 84 C on Monday, fire Tuesday possibly caused by hydrogen explosion at pool holding spent fuel rods, fire observed Wednesday at building housing reactor, pool water level feared receding, renewed nuclear chain reaction feared, only frame remains of reactor building roof.
-- Reactors No. 5, 6 - Under maintenance when quake struck, some fuel rods left in reactor cores, water temperatures in spent-fuel storage pools increased to about 64 C on Thursday.
-- Spent-fuel storage pools - Cooling functions lost at reactors No. 1 to 4, water temperatures or levels unobservable at reactors No. 1 to 4, no immediate threat to water level at common spent fuel pool.
Fukushima Daini plant
-- Reactors No. 1, 2, 4 - Operation suspended after quake, cooling failure, then cold shutdown.
-- Reactor No. 3 - Operation suspended after quake, cold shutdown.