As though it wasn’t bad enough already. The NY Times reports that the meltdown may have already escaped containment and begun boring through the concrete floor, according to a computer simulation of the original accident.
Soon after an earthquake and a tsunami on March 11 knocked out cooling systems at the power plant, nuclear fuel rods in three of its six reactors overheated and slumped, the operator, the Tokyo Electric Power Company, has said.
In the No. 1 reactor, the overheated fuel may have eroded the primary containment vessel’s thick concrete floor, and it may have gotten almost within a foot of a crucial steel barrier, the utility said the new simulation suggested. Beneath that steel layer is a concrete basement, which is the last barrier before the fuel would have begun to penetrate the earth.
Tepco based the simulation on projections of decay heat released by the nuclear fuel and other estimates. The results suggest that the uranium fuel rods at the No. 1 reactor were most badly damaged, Mr. Matsumoto said, because it lost cooling water before the other two reactors did. The fuel rods were exposed for several hours before fire trucks could pump in emergency seawater.
Because the simulation suggests that heat released as a result of radioactive decay “far overwhelmed” the effect of the cooling water, he said, and because temperatures in the inner pressure vessel that originally housed the fuel are thought to have dropped quickly, Tepco now assumes that “100 percent of the fuel at Unit 1 has slumped” into the outer primary containment vessel.
I still believe that nuclear power is a good stopgap measure while we develop alternate means of power, including geothermal, solar and wind. The main problem with nukes is not that a bad situation is possible, but that we’ve had a very long time to try to implement better safety protocols and we as a species just keep fucking it up with our own corner-cutting and profiteering. For how well those plants should have been able to weather the tsunami, they failed catastrophically and at too many points. The catastrophe wasn’t even a single-point-of-failure one, and yet it should have been reasonably foreseeable.