TOKYO, May 15 (UPI) -- Readings taken immediately after the March earthquake in Japan suggest it was the shaking rather than the tsunami that crippled a nuclear power plant.
A utility source told Japan's Kyodo news service the data indicates radiation levels inside the reactor building at the Fukushima No. 1 plant increased before the tidal wave knocked out the power to the facility.
Kyodo said the evidence could lead to a new review of nuclear plants across Japan
The general conclusion since the March quake had been that the Tokyo Electric Power Co. plant largely rode out the 9.0 magnitude shaker but lost its vital cooling system about an hour later when the tsunami knocked out the external emergency power generators.
Plant workers entered the No. 1 reactor building right after the quake and before the tsunami struck to assess the damage. But the dosimeters they were wearing quickly began showing readings of 300 milisieverts per hour, which Kyodo's source said pointed to a radiation leak.
"The quake's tremors may have caused damage to the pressure vessel or pipes," the utility official said.
