A foray of jellyfish into a cooling water pond at a Scottish nuclear power plant kept its nuclear reactors offline last Wednesday, a phenomenon that could become more common in the future.
Two reactors at EDF Energy’s Torness nuclear plant on the Scottish east coast remained closed for one day after they were manually shut down due to masses of jellyfish blocking cooling water filters.
Power plants draw water from nearby rivers or seas to cool down their reactors, however, if the filters that keep out marine animals and seaweed are clogged up, the station shuts down to maintain its temperature and safety standards.
Britain’s Office for Nuclear Regulation said that power plants follow a pre-planned program when such situations occur.
The most recent plant availability data from network operator National Grid showed Torness reactor 1 would be returning to service on July 5 and reactor 2, July 6, although, operator EDF Energy was unable to give a restart date.
Operators often take the opportunity presented by an unplanned stoppage to carry out maintenance work.
A spokesman for Britain’s largest nuclear power operator, EDF Energy, said:
“We are working to clear the jellyfish from the waters near the power station. This work, as well as monitoring the area for more jellyfish, is ongoing.”
Scientists say jellyfish obstructing power plants is not a common occurrence in England, though it has happened more often in other countries like Japan.
Water temperatures off the east coast of Scotland are currently 13 degrees Celsius, that is one degree above average levels for this time of the year.
Increasing global warming and fishing activity are giving jellyfish populations a boost, potentially making jellyfish invasions at nuclear power plants located near the open sea increasingly common in the future.