Within two hours of the massive earthquake that jolted Japan at 2:46 p.m. on March 11, 2011, the Japanese government received notice that an "Article 15 event" had occurred at the Fukushima No. 1 Nuclear Power Plant. "Article 15" refers to the Act on Special Measures Concerning Nuclear Emergency Preparedness, and the "event" was the complete failure of the plant's emergency cooling system. Under the Act, such an event is deemed indicative of a “nuclear emergency situation” requiring the issuance of a “Declaration of an Emergency Situation.” Such a declaration was put out at 7:03 p.m. Its sparse text bears repeating in full (my translation):

"At 16:36 on March 11, 2011, an incident of the type specified in Article 15 (1) (ii) of the Act on Special Measures Concerning Nuclear Emergency Preparedness occurred at the Tepco Fukushima No. 1 Nuclear Power Plant. It being recognized that urgent measures are required to prevent the spread of a nuclear disaster, a declaration of a nuclear emergency situation is hereby issued under the provisions of the aforementioned Article."

Although drafted in great haste, the declaration is nonetheless interesting for several reasons. First, it does not identify what sort of nuclear emergency it was declaring, even though the government knew and the law lays out a variety of clearly defined triggering events. Such information might have been relevant to a wide variety of people; after all, the stated purpose of the Act is to protect "the lives, bodies and properties of citizens from a nuclear disaster."