From Yomiuri Shinbun (3:03AM JST 10/2/2011):
Details of an interim report by TEPCO's internal "Fukushima nuclear accident investigation committee" (headed by Vice President Masao Yamazaki) were revealed.
The committee reversed the company's position that there had been a hydrogen explosion in Reactor 2, and now concluded there was no such explosion. As to the tsunami that triggered the accident, the committee says "it was beyond expectations"; of the delay in initial response to the accident, the committee concludes "it couldn't be helped". Overall, the report looks full of self-justification. TEPCO plans to run the report with the verification committee made of outside experts before it publishes the report.
At Fukushima I Nuclear Power Plant, the Reactor 1 reactor building blew up in a hydrogen explosion in the afternoon of March 12, followed by a hydrogen explosion of Reactor 3 in the morning of March 14. Further, in the early morning on March 15, there was an explosive sound, and the damage to the Reactor 4 reactor building was confirmed. Right after the explosive sound the pressure in the Suppression Chamber of Reactor 2 dropped sharply, which led TEPCO to conclude that there were near-simultaneous explosions in Reactors 2 and 4. The Japanese government reported the events as such in the report to IAEA in June.
So then what does TEPCO now think happened in Reactor 2 in the early morning on March 15? Yomiuri doesn't say in the article text, but at the bottom of the illustration that accompanies the article it says:
"There was no explosion, but a possibility of some kind of damage to the Containment Vessel."
So, before TEPCO completely changes story, here's what they say happened on Reactor 2 on March 15 (from the daily "Status of TEPCO's Facilities - past progress" report, page 6):
It says "an explosive sound was heard" at 6AM on March 15. The Reactor 4 explosion occurred before the Reactor 2 "explosion" which TEPCO now says never happened.
The two sounds are 14 minutes apart, and TEPCO now claims they misheard the second one and there was no explosion in the Suppression Chamber of Reactor 2.
(By the way, the fire spotted at 9:38AM on March 15 on Reactor 4 was never reported to the local fire department or the local government, as I reported on March 15.)
Well I can't wait to read their report and see how they explain away how Reactor 2 is supposed to have spewed more radioactive materials far and wide than any other Reactors.