<
https://reneweconomy.com.au/swarming-jellyfish-force-shutdown-of-french-nuclear-power-plants-for-second-time-in-a-month/>
"Two French nuclear power stations have had to partially shut down operations
in the past month due to swarms of jellyfish infiltrating the pumping station
filters.
In an example of how the effects of climate change can have wildly unlooked-for
consequences, France’s government-owned electric utility company EDF has had to
twice shut down operations of nuclear power reactors at two separate nuclear
power plants in the past month because of the jellyfish swarms.
The 5.5-gigawatt (GW) Gravelines nuclear power plant was forced to shut down
production at four of its six nuclear reactors on August 10 and 11 due to what
EDF described as “the sudden and massive arrival of jellyfish” at the filters
of the power plant’s pumping station.
Staff at the power plant were able to maintain and clean the filters of the
seaborne invaders, although several smaller swarms apparently arrived in the
following days, including a ‘notable’ swarm on August 23 which forced one of
the reactors to again be shut down as a precautionary measure.
Less than a month later, on September 6, the 5.2 GW Paluel nuclear power plant
was also forced to shut down one of its four nuclear reactors “following the
arrival of jellyfish at the filters”.
EDF also chose to reduce production at another of its reactors “as a
precaution”, which left only one reactor operational, with a third already down
for scheduled maintenance.
Three of the four reactors were all operational by Saturday, September 6, with
the No. 2 reactor still shut down for scheduled maintenance.
EDF explained in August that the “arrival of sticky, gelatinous jellyfish” in
the pumping station ‘exceeded expectations’ and created a “sudden increase in
blockages”.
Both power stations are situated on the north-west coast of France and use
seawater pumped directly from the North Sea or English Channel for their
cooling systems. This obviously opens the door for potential foreign objects to
enter the pumping station, which is why they use pre-screens and filter drums.
However, the arrival of so many jellyfish was to much for the filtering
systems, necessitating the shut down of the reactors which could have
potentially received less water than was necessary to maintain safe operations.
According to EDF, the culprit was the Rhizostoma Octopus, also known as the
barrel jellyfish, dustbin-lid jellyfish, or frilly-mouthed jellyfish.
Jellyfish like the Rhizostoma Octopus follow warm water currents for their
yearly reproduction cycle. In the past, the seasonal shift in water
temperatures would eventually cause conditions to become unfavourable for the
jellyfish to remain.
However, according to a report in
The Guardian in early August, record-high
sea surface temperatures in Spring, which have been exacerbated by global
heating, have proven particularly enjoyable for jellyfish this year, resulting
in what experts describe as a population bloom and prolonged stay in UK
waters."
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
