Kyodo News reports (3/3/2012), nearly one year later:
SPEEDI simulation "cannot be made public", according to a document by Ministry of Education and Science
It was revealed on March 2 by speaking with the people involved at the Ministry of Education and Science that an internal memo was created on March 15, 2011, 5th day of the Fukushima I Nuclear Power Plant accident, which shows then-Minister Yoshiaki Takagi and top officials at the Ministry of Education and Science held a meeting that day and agreed that they "cannot make the SPEEDI simulation results public".
The Ministry of Education denies part of the story, saying "The memo was created by the secretariat but it is inaccurate. There was no clear decision on whether to make them public."
No minutes of the Ministry of Education's meetings have been made public over the SPEEDI results right after the accident.
You can be pretty sure that no minutes exist.
The Ministry of Education and Science was in charge of SPEEDI. What was made public at that time was that SPEEDI didn't work.
I remember Professor Kunihiko Takeda of Chubu University saying right around March 15 last year that the government (Ministry of Education) decided to hide the result of SPEEDI simulation because it was very, very bad, showing serious radioactive contamination over a wide area.
Well he was right.