New Threat To Seaside Nuclear Plants, Datacenters: Jellyfish 123
Nerval's Lobster writes "One of the largest nuclear-power plants in the world was forced to shut down temporarily Sept. 29, after pipes that bring Baltic Sea water in to cool the plant's turbines became clogged with tons of jellyfish. The sudden influx of common moon jellyfish overwhelmed the screens and filters that keep flotsam and most sea life out of the Oskarshamn nuclear plant in southeastern Sweden. The plant was forced to shut down its No. 3 reactor – the largest boiling-water reactor in the world, which generates 1,400 megawatts of electricity when it is jellyfish-free and running at full power. The reactor stayed down until early Oct. 1, after the jellyfish had been cleared out and engineers approved the cooling system as invertebrate-free. It's not easy to overwhelm the cooling system for a nuclear power plant, but Oskarshamn's is unusually resilient. There is a separate intake- and cooling system for each reactor, all of which were designed for the brackish, polluted water in that area of the Baltic Sea. Most datacenters are too far inland to worry about jellyfish in their cooling water, though green-IT-promoters Vertatique estimated that a 5,000-sq.-ft. datacenter would consume almost 9 million gallons of water for cooling. That means ocean-side datacenters that use sea water for cooling (such as Google's datacenter in Hamina, Finland — also on the Baltic Sea) are just as susceptible to jellyfish attacks as nuclear power plants."
Rampant Jellyfish (Score:5, Interesting)
There's been a huge increase in the jellyfish populations around the world, they've been thriving as the seas warm up - more plankton equals more jellyfish. Fishing boats are catching huge nets of the things when they're supposed to be picking up fish. It's such a problem, there's a Japanese effort to get people to eat jellyfish sushi.
Why pump in sea water? (Score:5, Interesting)
Does it not make more sense to use clean, filtered water to transfer the heat out into the ocean? The heat exchanger can sit in the ocean to facilitate removing heat without the worry of having jellyfish clogging filters. Effective cooling capacity might be reduced without an active water stream going over the heat exchanger, but this can be compensated for by using a larger one.
The only possible problem I can see is the build-up of aquatic life on the head exchanger. They would require periodic cleaning. But unlike filters, you would not have to shut down the cooling system to do so. In addition, you don't have to worry about there being any sudden changes in the cooling capacity of the system so it should be much easier to plan and perform the cleaning.
Hope you like 'em! They'll dominate in a few years (Score:5, Interesting)
Ah, jellyfish. This is one of my favourite up-and-coming ocean doomsday scenarios.
Consider:
- No hard parts, so unaffected by ocean acidification
- Perform well in anoxic (low oxygen) environments
- Eat everything
- Have almost no nutritional value of their own
- Can shrink when food resources are low, and simply eat less
- Few natural predators
- Some species are effectively immortal by way of reverting to earlier life stages
To a certain extent, it's a bit of a miracle that the oceans managed to ever keep them in check, but oxygenation of the oceans created whole ecosystems of creatures that could--as a group--effectively compete against jellyfish.
There's no one predator that we can release that will keep the jellyfish contained or under control. It takes whole ecosystems to combat a real jellyfish problem.
Here's a review of a book written by Dr. Lisa Gershwin (composer Gershwin's granddaughter, I believe) http://www.nybooks.com/articles/archives/2013/sep/26/jellyfish-theyre-taking-over/?pagination=false [nybooks.com]
Fortunately, humans are adept at obliterating species if they can get a taste for them. Better acquire a taste for them quick.
Re:Blender blades (Score:4, Interesting)
Considering how much of an invasive species jellyfish are, drastic measures to get rid of them might become necessary and "raw jellyfish in, cooked jellyfish out" might end up not being such a bad thing.
One thing some water treatment plants do is put a conveyor mesh in front of intakes. Jellyfish and other solids get tangled in the mesh, lifted as the mesh rotates, gets scraped off and dumped with solid waste. If they do not care about cleaning up solid waste in the water, they can dump the intake's catch in the return stream.
Re:Rampant Jellyfish (Score:5, Interesting)
We have been seeing ** lots ** more jellyfish the last several years in SE Alaska. This summer we kayaked through a half kilometer long field of them. Very, very trippy but fisherman absolutely hate them. You can't get them to move. If you net them you can't get their slimy bodies off the net. Nothing local eats them very effectively. Shooting at them with a shotgun doesn't do much except waste ammo and scare tourists.