Tokyo Electric Power Co. in early December made public an interim report by a study panel that it had appointed itself on the disaster that occurred at its Fukushima No. 1 nuclear power plant following the March 11 earthquake and tsunami. The report details the unfolding of the disaster from the loss of all electric power sources to the meltdowns of the cores of three reactors.

Unfortunately, the report is loaded with self-justifying excuses. It is clear that the investigation of the disaster cannot be left solely to Tepco. Other entities, including the government third-party examination panel, the Diet examination panel and nongovernmental organizations, should carry out thorough investigations of their own and break any attempt by the nuclear power establishment to hide or distort information.

Tepco's official worst-case tsunami scenario for the plant involved a wave with a maximum height of 5.7 meters. Although in 2008 the company had carried out an assessment that predicted the possibility of a tsunami with a maximum height of 10.2 meters striking the plant, Tepco did not take measures to prepare against such an event. The report states that Tepco did not take such measures because the 10.2-meter scenario was based on a "groundless hypothesis," despite the fact that its own staff had made the assessment, and despite having been warned in the past by outside experts that a massive tsunami could strike the region.