Wave of jellyfish shuts down Swedish nuke reactor (Update)

Wave of jellyfish shuts down Swedish nuke reactor
In this May 22, 2008 file photo, an exterior view of the Oskarshamn nuclear power plant in Oskarshamn, southeastern Sweden. Officials at OKG, which runs the Oskarshamn nuclear power plant in southeastern Sweden, say they had to shut down reactor three on Sunday, Sept. 29, 2013 after tons of jellyfish clogged up pipes bringing cooling water to the plant. (AP Photo/TT News Agency, Mikael Fritzon)

It wasn't a tsunami but it had the same effect: A huge cluster of jellyfish forced one of the world's largest nuclear reactors to shut down—a phenomenon that marine biologists say could become more common.

Operators of the Oskarshamn nuclear plant in southeastern Sweden had to scramble reactor number three on Sunday after tons of jellyfish clogged the pipes that bring in cool water to the plant's turbines.

By Tuesday, the pipes had been cleaned of the jellyfish and engineers were preparing to restart the reactor, which at 1,400 megawatts of output is the largest boiling-water reactor in the world, said Anders Osterberg, a spokesman for OKG, the plant operator.

All three Oskharshamn reactors are boiling-water types, the same technology at Japan's Fukushima Daiichi plant that suffered a catastrophic failure in 2011 after a tsunami breached the facility's walls and flooded its equipment.

Jellyfish are not a new problem for nuclear power plants. Last year the California-based Diablo Canyon facility had to shut its reactor two after gobs of sea salp—a gelatinous, jellyfish-like organism—clogged intake pipes. In 2005, the first unit at Oskarshamn was temporarily turned off due to a sudden jellyfish influx.

Nuclear power plants need a constant flow of water to cool their reactor and turbine systems, which is why many such plants are built near large bodies of water.

Marine biologists, meanwhile, say they would not be surprised if more jellyfish shutdowns occur in the future.

Wave of jellyfish shuts down Swedish nuke reactor
In this Friday, Dec. 17, 2010 file photo, moon jellyfish are pictured in an aquarium of the Oceanographic Museum of Monaco. It wasn't a tsunami but it had the same effect: A wave of jellyfish was huge enough to force one of the world's largest nuclear reactors to shut down—a phenomenon that marine biologists say could become more common. Operators of the Oskarshamn nuclear plant in southeastern Sweden had to scramble reactor number three on Sunday, Sept. 29, 2013, after tons of jellyfish clogged the pipes that bring in cool water to the plant's turbines. (AP Photo/Lionel Cironneau, File)

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

The species that caused the Oskarshamn shutdown is known as the common moon jellyfish.

"It's one of the species that can bloom in extreme areas that . . . are overfished or have bad conditions," said Moller. "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."

Moller said the biggest problem was that there's no monitoring of jellyfish in the Baltic Sea to produce the data that scientists need to figure out how to tackle the issue.


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Oct 01, 2013
Huh thats funny and it is a good reason why they should all be mothballed everywhere and the fissile materials be stored for use in nuclear propulsion and modular reactors and robotic earth borers for planetary colonization. But certainly not for anything here as even JELLYFISH for godsakes can screw them up.

This sort of thing could never happen to solar thermal plants which may nevertheless be susceptible to locusts, moths, and migrating butterflies.

Oct 01, 2013
Nuclear power plants need a constant flow of water to cool their reactor and turbine systems, which is why many such plants are built near large bodies of water.


That's putting the cart before the horse.

Nuclear powerplants are built near large bodies of water because their reactors have to be built so large, because of political opposition that campaigned to minimize the number of reactors. Any industry that can only get one or two commissions at a time has to think big and build big to be profitable.

But smaller modular designs would do with a lot less cooling because they could be spread out, and would consequently be faster to react and safer to operate because containment during accidents would be much less difficult.

The main difficulty is to get any permits to build them.


Oct 02, 2013
Cold Fusion.

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