This means the area surrounding the Fukushima plant should have been evacuated right away -- but wasn't. And this, of course, is the problem when something as potentially catastrophic as a nuclear power plant is run by the private sector, whose executives define safety standards as buying enough politicians to cover your ass.

Tokyo Electric Power Co. concealed data showing spikes in radiation levels at the Fukushima No. 1 nuclear power plant in March, one day before a hydrogen explosion injured seven workers.

The Asahi Shimbun obtained a 100-page internal TEPCO report containing minute-to-minute data on radiation levels at the plant as well as pressure and water levels inside the No. 3 reactor from March 11 to April 30.

The data has never been released by the company that operates the stricken plant.

The unpublished information shows that at 1:17 p.m. on March 13, 300 millisieverts of radiation per hour was detected inside a double-entry door at the No. 3 reactor building. At 2:31 p.m., the radiation level was measured at 300 millisieverts or higher per hour to the north of the door.

Both levels were well above the upper limit of 250 millisieverts for an entire year under the plant's safety standards for workers. But the workers who were trying to bring the situation under control at the plant were not informed of the levels.