Dead rodents shut down Fukushima cooling systems

Two years after the earthquake and massive tsunami, the nuclear power plant needs permanent solutions, not makeshift ones.

Two years ago, an earthquake and tsunami knocked out the cooling system of the Fukushima Daiichi nuclear plant – and the core meltdown released radiation across northeastern Japan. This week, the cooling system was shut down because of a dead rodent, and this wasn't the first time that's happened. New York Times reports.

On Monday, a team from the United Nations nuclear watchdog agency praised the plant’s operator, Tokyo Electric Power Company (Tepco), for its progress in dismantling the three damaged nuclear reactors -- but also recommended the company strengthen its ability to cope with unexpected events as it continues to clean up the damaged reactors for the next few decades.

While Tepco has been working to make the plant safer, it was often doing so “with temporary systems or mobile systems,” says International Atomic Energy Agency (IAEA) team leader Juan Carlos Lentijo. “There is a need for more permanent systems.”

The makeshift nature of some of those cooling systems was exposed again on Monday when Tepco said it had temporarily switched off one of them after a dead rat was found nearby. The system was off for four hours while workers made sure there was no damage to electrical circuits.

Last month, a short circuit caused by a dead rat shut down a similar cooling system for more than a day.

Luckily, the shutdowns didn’t create any danger… but there have now been three shutdowns in five weeks. Lentijo says Tepco must upgrade sensors and other mechanisms for identifying problems in order to respond more promptly.

But Tepco's biggest immediate challenge, according to Lentijo, is managing the huge and growing amount of radioactive water at the plant: some 100,000 gallons of groundwater a day enters the damaged reactor buildings and becomes contaminated.

[Via New York Times, Wall Street Journal]

Image by Japan Ministry of Land, Infrastructure and Transport via Wikimedia

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