Evidence to prove reactor2 also possibly exploded in 311 was found / Hole on suppression chamber

On 1/30/2014, Tepco announced there is a hole on suppression chamber of reactor2 from their simulation.

Reactor2 has been a “mystery” of 311. Some workers heard the explosive sound but no explosion was observed like other reactors. However, the building is severely contaminated and it hasn’t been known what actually happened in reactor2. The new simulation result strongly supports reactor2 also went under some explosion in 311.

(cf, [Column] (Back in 2011) Shock strong enough to shake outside of the reactor, deep enough to keep the building sound [URL])

Tepco has been attempting to measure the water level in suppression chamber of reactor2 since last September. However, because the suppression chamber was deteriorated worse than anticipated, they couldn’t obtain the credible data in the first investigation. (cf, Tepco “Suppression chamber of reactor2 is more deteriorated than expected” [URL2])

From 1/14/2014 ~ 1/16/2014, Tepco investigated the water level by ultrasonic waves again and confirmed the water level was around 5.7m from the bottom of suppression chamber. In three measurements, the water level was always 10 ~ 30mm lower than outside of suppression chamber.

From these gaps of the water level, Tepco simulated there is possibly a hole of 8~9 cm2 on the suppression chamber.

http://www.tepco.co.jp/nu/fukushima-np/roadmap/images/d140130_06-j.pdf