Nuclear engineers in southeastern Sweden have been wrestling with a giant swarm of jellyfish that forced the shutdown of the world’s largest boiling-water reactor. http://www.nytimes.com/2013/10/02/world/europe/jellyfish-invasion-paralyzes-swedish-reactor.html?ref=world   The plant’s operator said that over the weekend, a huge cluster of moon jellyfish clogged the cooling water intake pipes at the Oskarshamn nuclear power plant on the Baltic Sea coast, forcing the complex’s 1,400-megawatt Unit 3 to shut down.Mr. Osterberg said that the jellyfish had entered the pipes at about 60 feet below the surface of the sea, where the plant collects cold water to cool its reactor and turbine systems.
Nuclear power plants are often placed next to large bodies of water, and jellyfish blooms are common even in waters that are not environmentally damaged, so jellyfish clogs are a recurring problem. Mr. Osterberg noted that the plant had a similar episode in 2005.
The Oskarshamn nuclear power plant uses the same technology employed at Japan’s Fukushima Daiichi nuclear complex, where a powerful earthquake and tsunami in 2011 caused the worst nuclear disaster since Chernobyl.