The Nuclear and Industrial Safety Agency (NISA) is currently reviewing the document to determine which part can be safely disclosed to the public, but it doesn't seem to matter anyway.
In yesterday's (October 17, 2011) joint press conference of all relevant government agencies and TEPCO, TEPCO submitted the progress report on its "roadmap" (link is TEPCO's English) to stabilize the situation at Fukushima I Nuclear Power Plant. In the press conference, there was a mention of the "Severe Accident Manual" that TEPCO had been criticized for blackening it out almost completely for "confidentiality" concern.
Independent journalist Ryuichi Kino asked TEPCO's Matsumoto about the Manual, and it turned out that TEPCO didn't (and couldn't) use the Manual anyway. Kino tweets:
So I thought TEPCO must have used this Severe Accident Manual on March 11 earthquake. [TEPCO's] Matsumoto's answer was "No". The reactors were automatically scrammed after the earthquake, which was the normal operating procedure. So the company proceeded with the normal operating manual. So I asked when TEPCO started using the Severe Accident Manual. The answer was that it never did.
The events at the plant after the tsunami were beyond what was expected, and procedures like opening and closing the valves in the complete darkness after all-station blackout are not in the Severe Accident Manual. So, just like this article (Kyodo News) says, the Manual was not usable from the beginning.
The link Kino gives goes to Kyodo News Japanese article (10/2/2011). Most newspapers used the part about "no hydrogen explosion in the Reactor 2 suppression chamber", but not about the Severe Accident Manual. From 10/2/2011 Kyodo News:
It was revealed on October 2 that TEPCO's accident investigation committee concluded that the Severe Accident Manual had been useless. The Manual had assumed that the emergency power supplies like diesel generators would be operational; in reality they all failed, and couldn't be used to deal with the accident.
The committee also determined that there was no hydrogen explosion near the Suppression Chamber of Reactor 2, a different conclusion from what it had been assumed.
TEPCO's (for that matter, all nuclear power plant operators') severe accident procedure relied on having electricity available somehow.
So what DID TEPCO use to deal with the accident?