TEPCO says no explosion occurred at No.2 reactor, NHK, November 29, 2011 (Emphasis Added):
[...] NHK has obtained Tokyo Electric Power Company’s interim report on the nuclear accident that was triggered by the earthquake and tsunami on March 11th. [...]
The company concluded in the report that there was no explosion at the No. 2 reactor, and that a blast at the No. 4 reactor was mistakenly believed to have occurred at the No. 2.
Later that day, pressure inside the No. 2 reactor vessel dropped sharply, and radiation levels near the plant’s main gate rose above 10 millisieverts per hour, then the highest level so far.
The interim report fails to specify how the leakage occurred at the containment vessel, just saying that gas in the vessel was somehow released into the air.
Watch video here.
NHK: “Investigators from TEPCO still can’t determine how radioactive substances were released and why“
NHK: “Workers reportedly heard any explosion near the containment vessel of the No. 2 reactor”
NHK: “Researchers believe No. 2 released the most radioactive materials of all reactors at the plant”
Shinichiro Kado, an associate professor at the University of Tokyo (SOURCE: “Expert urges probe of No.2 reactor leak”): “The containment vessel is the final fortress for keeping radioactive substances trapped inside the reactor. Its’ a cornerstone of the integrity of a nuclear plant. The breach of the containment vessel itself is extremely grave.”
NHK adds: “The spike in radiation levels following unspecified trouble at the No.2 reactor on March 15th was much more prominent than on March 12th or 14th, when explosions hit the No.1 and No.3 reactors.”
Was the spike had related to the similarly-timed “blast” at the spent fuel pool at Reactor No. 4? See: Top scientists refute Japan gov't: "Copious quantities" of radioactivity leaked from Spent Fuel Pool No. 4 -- A "significant part" of overall cesium release
At least the reactors had containment vessels, unlike the spent fuel pools…
Published: November 29th, 2011 at 12:00 am ET