TOKYO (AFP) - A rat may have caused a power cut that knocked out cooling systems at Japan’s tsunami-wrecked Fukushima nuclear plant, the operator said Thursday, an episode that highlighted the jerry-rigged nature of the fix. Equipment keeping spent nuclear fuel at a safe temperature in four different pools was out for up to 29 hours from Monday, with Tokyo Electric Power Company (TEPCO) admitting its recovery work was sometimes less than perfect.The incident was a reminder of the precarious state of the plant two years after the tsunami, which sparked meltdowns in three reactors, spewing radiation over land and sea and forcing tens of thousands from their homes.