Tokyo Electric Power Co. confirmed Monday that a rat disabled the cooling systems of the spent-fuel pools at the meltdown-stricken Fukushima No. 1 power plant last week.
The animal apparently touched a live wire after managing to get into the plant's truck-mounted switchboard, creating a short circuit that knocked out power to the pools' cooling systems on the evening of March 18, the beleaguered utility said.
The 25-cm rodent was found dead in a ring of fried fur within the switchboard apparatus.
Masayuki Ono, Tepco's spokesman on the rat blackout, said the utility will take stronger measures to prevent small animals from entering the switchboard.
It took about 29 hours to return the spent-fuel pools to their normal temperatures.