Jellyfish shut reactor at Oskarshamn nuclear power plant in Sweden Oskarshamn nuclear power plant's reactor number three was shut down after tonnes of jellyfish clogged up pipes bringing cooling water to the plant. Picture: Bob Barker Source: DailyTelegraph THE Swedish operators of one of the world's largest nuclear reactors say they are preparing to restart the facility after it had to be shut down because of a wave of jellyfish. Officials at OKG, which runs the Oskarshamn nuclear power plant in southeastern Sweden, say they had to shut down reactor three on Sunday after tonnes of jellyfish clogged up pipes bringing cooling water to the plant. OKG spokesman Anders Osterberg said that the water was needed to cool the reactor's turbines but there was no risk of an accident. Osterberg says the plant faced a similar scenario in 2005 when jellyfish clogged the water intake pipe of reactor one. The Oskarshamn facility has three reactors, with number three being the world's largest boiling water reactor.