A rat might have been the cause for the power interruption that stopped the cooling systems at Fukushima plant on Monday.
Equipment keeping spent nuclear fuel at a safe temperature in four different pools was out for up to 29 hours from Monday. Tokyo Electric Power Company (TEPCO) admitted that its repairing work was sometimes less than perfect, according to the international press.
“We suspect a small animal may have caused a short-circuit in a switchboard”. The short-circuit led to the power interruption, which disabled the cooling systems for used fuel pools, according to a spokesman for TEPCO.
“We cannot be sure exactly what it was, but can say what we saw at the scene was the body of a dead animal below the switchboard,” he said.
“In our investigation we will concentrate on getting assurances that it was definitely this animal that caused the short-circuit.”
A photograph released by TEPCO shows an animal similar to a rat, with a body around 15 centimetres long.
On Monday night, the power was cut at a building that serves as the central command for work to contain the nuclear accident and dismantle the reactors.
Electricity was partially restored by Tuesday, but the supply was brought under control only after 29 hours since the original outage.