Jellyfish, Bringing Down the House…or the Nuclear Plant, Actually


Who knew jellyfish could be such a menace?  I surely didn’t.  However, in the last few days I’ve read a couple of articles about jellyfish clogging up the cooling systems of nuclear plants.  The Oskarshamn nuclear plant in Sweden had to shut down due to the gelatinous creatures on October 1st.  They clogged up the pipes that pump water into the turbines in the number three reactor.

Oskarshamn is a boiling water reactor.  According to Wikipedia, a BWR works by using the reactor core to heat the water and turning it into steam.  The steam drives a steam turbine, generating electricity.  Fukushima Daiichi is another example of a boiling water reactor, which is the second most common nuclear reactor used in generating electricity.

This isn’t something new for operators of these facilities.  According to this article, last year in California the Diablo Canyon facility was forced to shut down reactor two because of sea salp clogging intake pipes. (These creatures are gelatinous also, similar to jellyfish.) October 1st was not the first time the reactor Oskarshamn had been attacked by gelatinous animals.  In 2005 jellyfish clogged up the cooling pipes.

So why are jellyfish such a hazard?  Some of these species are incredibly hearty creatures.  It doesn’t matter if the oxygenation levels in the water are low or if there are algae blooms, these moon jellyfish can still thrive.