A huge cluster of jellyfish made one of the world's largest nuclear reactors shut down...but soon, robots might shred the jellyfish up.
Marine biologists warn that jellyfish clogging nuclear reactors may become more common.
The Oskarshamn nuclear plant in southeastern Sweden said that tons of jellyfish swam into the pipes that bring cool water to the plant's turbines. On Sunday, workers at the plant had to scramble reactor number three due to the blob-like creatures.
A new system called the Jellyfish Elimination Robotic Swarm, JEROS, may eradicate the problem. It was developed at the South Korean research university KAIST in an effort to reduce jellyfish attacks along Korea's southwest coast. Jellyfish have hampered the fishing industry in Korea; they clog nets, eat fish eggs, and feed on plankton that are normally the fish's food. Associate robotics professor Myung Hyun made the system.
In the JEROS, robots float on the water and use a GPS system and camera combination. They find jellyfish swarms then shred them up with a special propellor.
The robots automatically determine the optimal path and formation to kill the jellyfish swarms, then they move in for the kill. The first version could kill 900 pounds an hour, and now, they're up to almost 2000.
By Tuesday, the in Sweden, pipes were cleaned and engineers got ready to restart the reactor. It's the largest boiling-water reactor in the world and has 1,400 megawatts of output, according to Anders Osterberg, a spokesman for OKG, which operates the plant.
Boilding-water reactors are the same type that were used in Fukushima, Japan at the Daiichi plant, which suffered a catastrophic failure after a tsunami in 2011.
The jellyfish were likened to a tsunami in the Oskarshamn plant-but disaster was averted because engineers were able to shut down the reactor.
This isn't the first time jellyfish have posed an issue for nuclear power plants, and the problem may increase, scientists warn. Last year, Diablo Canyon, a plant in California, had to shut down its reactor after sea salp, a jellyfish-like organism, clogged intake pipes.
"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."
In 2005, the first unit at Oskarshamn was temporarily turned off due to jellyfish.
Because nuclear power plants need constant cool water, they are often built near large bodies of water. However, large bodies of water are in peril due to toxins and global warming. For example, common moon jellyfish, which caused the Oskarshamn plant to shut down, proliferate in waters that are over-fished.
"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 added that scientists are not currently monitoring jellyfish in the Baltic Sea, and thus don't have enough data to know the extent of the problem or how to tackle it.
Watch a video about this phenomenon below: