Jellyfish Shutdown the World’s Largest Nuclear Power Plant

In 2011 a tsunami hit the Fukushima Daiichi nuclear power plant, flooding its equipment, causing massive failures to cooling systems, and eventually leading to a meltdown and explosion.

The Oskarshamn nuclear power plant in Sweden, is the largest in the world and utilises the same boiling-water technology as Fukushima. Recently it's reactor number three had to be shutdown after a different kind of wave threatened its operating systems; not a tsunami, but a wave of jellyfish.

The 1,400 megwatt reactor had to be shut down on Sunday after tonnes of jellyfish clogged the pipes that take cool seawater to the turbines. Anders Osterberg, a spokesman for the power plants operator, OKG, said that by Tuesday all of the jellyfish had been cleaned from the pipes, and that the reactor was being prepared to be restarted once more.

Oskarshamn Nuclear Power Plant. (Alstom)

Marine biologists have warned that this issue with jellyfish is becoming more common, and that it could become a serious threat in the future.

Last year the Diablo Canyon nuclear power plant in California had to shutdown its reactor number two after it became clogged with a jellyfish-like organism; and in 2005 reactor one at Oskarshamn had to be shutdown briefly due to jellyfish.

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Nuclear power plants are often built on the coast, or next to lakes and reservoirs, due to their need for a constant source of water to cool their reactors and turbines. This means that increasing populations of jellyfish could become a new issue that must be dealt with.

Lene Moller, a reasearcher a the Swedish Institute for the Marine Environment, said that "it's true that there seems to be more and more of these extreme cases of blooming jellyfish. But it's very difficult to say if there are more jellyfish, because there is no historical data."

Moon Jellyfish bloom.

The species of jellyfish involved at the Oskarshamn plant is called the Moon jellyfish.

Moller explained that "it's one of the species that can bloom in extreme areas that are overfished or have bad conditions. The moon jelly likes these types of waters. They don't care if there are algae blooms, they don't care if the oxygen concentration is low. The fish leave and (the moon jelly) can really take over the ecosystem."

By. Charles Kennedy of Oilprice.com