INES-event
INES 3

Loss of cooling function and water supplying function on the spent fuel pool due to the big tsunami.

Fukushima Dai-ichi Nuclear Power Station Unit 4, which was in shutdown mode, was attacked by the Tohoku regional Pacific Ocean Offshore Earthquake around 14:46 (JST) in March 11, 2011.
After that, the power station was attacked by a tsunami.
Electricity rooms and seawater pump rooms were flooded, and the cooling function and water supplying function on the spent fuel pool became inoperable. The temperature of the spent fuel pool has been increasing, and the water level of the spent fuel pool was thought to be decreasing.
The water in the spent fuel pool boiled by residual heat of spent fuels, and the reactor building was damaged by an explosion which seems to be a hydrogen explosion.
It is carrying out to pour the sea water for cooling spent fuels.

Location: FUKUSHIMA-DAIICHI-4
Event date: Fri, 11-03-2011
Nuclear event report
Legenda & explanation