Science

Floating nuclear plants could prove tsunami-proof

Floating nuclear plants could ...
MIT proposes building floating nuclear power plants located 5 to 7 miles into the ocean, enabling the nuclear power plants to ride out a tsunami without sustaining damage (Image: Jake Jurewicz/MIT-NSE)
MIT proposes building floating nuclear power plants located 5 to 7 miles into the ocean, enabling the nuclear power plants to ride out a tsunami without sustaining damage (Image: Jake Jurewicz/MIT-NSE)
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Cutaway view of the proposed plant shows that the reactor vessel itself is located deep underwater, with its containment vessel surrounded by a compartment flooded with seawater, allowing for passive cooling even in the event of an accident (Image: Jake Jurewicz/MIT-NSE)
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Cutaway view of the proposed plant shows that the reactor vessel itself is located deep underwater, with its containment vessel surrounded by a compartment flooded with seawater, allowing for passive cooling even in the event of an accident (Image: Jake Jurewicz/MIT-NSE)
MIT proposes building floating nuclear power plants located 5 to 7 miles into the ocean, enabling the nuclear power plants to ride out a tsunami without sustaining damage (Image: Jake Jurewicz/MIT-NSE)
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MIT proposes building floating nuclear power plants located 5 to 7 miles into the ocean, enabling the nuclear power plants to ride out a tsunami without sustaining damage (Image: Jake Jurewicz/MIT-NSE)

The most frightening part of a tsunami hitting a nuclear power plant is what comes after – radioactive leaks that contaminate the water around the plant are exceedingly difficult to contain. The clean up of the radioactive water around the Fukushima Daiichi nuclear plant in Japan, which was struck by a tsunami in 2011, is expected to take decades. MIT researchers have come up with an alternative; they propose building floating nuclear plants, far enough offshore to simply ride out a tsunami and emerge unscathed.

The new design proposed by Jacopo Buongiorno, Associate Professor of Nuclear Science and Engineering at MIT and his colleagues, calls for constructing sturdy floating platforms, similar to the ones that support offshore oil and gas rigs. Light-weight nuclear reactors could be built on top of these platforms in shipyards, and then towed to appropriate locations offshore. Mooring the platform to the seafloor, would, they say, ensure that the nuclear power plant remains unaffected by a tsunami's waves. A power transmission line could connect the plant to the electrical grid.

"Tsunamis and earthquakes are no longer a source of risk for the nuclear plant," explains Buongiorno. "Essentially the ocean shields the seismic waves and the tsunami waves in relatively deep water, say 100 meters (300 ft) deep, are not big, so they don't pose a hazard for the plant."

It also becomes easy to avoid the biggest issue that leads to radioactive contamination in a damaged nuclear plant, the overheating of the reactor cores that lead to a meltdown, something that would be impossible in the ocean, according to the team.

"It’s very close to the ocean, which is essentially an infinite heat sink, so it’s possible to do cooling passively, with no intervention," says Buongiorno. "The reactor containment itself is essentially underwater."

Designing the plant in such a way that the ocean water automatically cools the nuclear reactors would, the researchers claim, prevent any radioactive leaks and fuel rod meltdowns, since it is possible to remove heat indefinitely.

Cutaway view of the proposed plant shows that the reactor vessel itself is located deep underwater, with its containment vessel surrounded by a compartment flooded with seawater, allowing for passive cooling even in the event of an accident (Image: Jake Jurewicz/MIT-NSE)
Cutaway view of the proposed plant shows that the reactor vessel itself is located deep underwater, with its containment vessel surrounded by a compartment flooded with seawater, allowing for passive cooling even in the event of an accident (Image: Jake Jurewicz/MIT-NSE)

The whole concept has been around for a while. The floating nuclear power plant that Russian scientists have been working on for several years is expected to be operational by 2016, but their nuclear plant is being built on a barge close to the shore.

The unique advantage of the MIT team's design, lies in mooring the nuclear power plants 5 to 7 miles (8 - 11 km) into the ocean, thereby giving the power plants the ability to weather any tsunami. Another advantage the distance offers is that the people on land won't have to relocate, in the event of an accident or an emergency out in the ocean. "The biggest selling point is the enhanced safety," says Buongiorno.

Decommissioning such a power plant could just be a matter of towing it away at the end of the nuclear reactor's lifetime. Since there's no size limit, floating nuclear power plants could rival their land-based counterparts; they could range anywhere from 50-megawatt plants to 1,000-megawatt plants, according to the scientists.

Placing them a few miles offshore, out of sight of cities would enable them to supply power reliably without posing any risk or using up valuable land resources. "The ocean is inexpensive real estate," says Buongiorno.

The researchers will be presenting their work at the Small Modular Reactors Symposium, hosted by the American Society of Mechanical Engineers, from April 15-17, at Washington, D.C.

Check out the concept video below.

Source: MIT

Floating nuclear plants could withstand earthquakes and tsunamis

29 comments
Matt Fletcher
This is by far the dumbest idea I have ever heard of regarding the safety and improvement of nuclear reactors. At sea level the sea is the most unpredictable, unstable, unforgiving, dangerous place to operate from on the planet and they want to put a floating nuclear reactor in it. Try this line of questioning: What happens if it is unable to float? Well it will sink. Then what? well it would contaminate the entire water supply around it (ocean to oceans) and make containment much more difficult if even possible. I have a great idea, why don't we just name it the Titanic now or better yet Oceanic Armageddon. Dr. Robert Oppenheimer (credited as the father of the atomic bomb) said nuclear power plants are much to dangerous to have anywhere on earth. Meaning he thought all power plants should be buried underground so if there was an explosion or meltdown it would be contained immediately. This is just plan stupid, the dumbest idea I have ever read, great going MIT. I am however very glad this was published in Gizmag because if I didn't see it I wouldn't be able to look into kill it before it has a chance to breath.
Seth Miesters
The way to make Nuclear Power safer is to switch to Thorium Fuel http://en.wikipedia.org/wiki/Thorium_reactor
Cyberxbx
You took the words from my mouth both Matt and Seth. Underground thorium plants, located underground in the places we collect the raw material from would be a good benefit for all. Thorium easily accessible in current mining operations. The way I see it, you dig a huge hole, place a Thorium reactor in the bottom, and put a huge dome lid over the top. now you have the strongest shape nearly impervious to winds protecting a valuable resource. And please for the love of Bill Nye, stop putting them in DISASTER ZONES!
BeWalt
Interesting. Poor, dying industry, trying so hard. On a side note, solar panels for electricity are now at parity with oil and even hydro power. Not yet including system costs but getting there, the curve has always pointed down since the 1950's when a watt of power from solar was ~ $1000. Right now, one solar-electric watt costs $0.70 to $1.50 depending on who you are and how much you buy. Use that number over a life time of 15 to 20 years, daily incoming sun 4 to 8 hours and, lo and behold, one kWh costs now ~5 cents. Gee, that's where a kWh from a barrel of oil is! (...on good days!). Many utilities, even hydro ones, charge far more than that for energy. The fun part is, after 15 years when written off, solar panels keep making electricity. Try that with an oil rig. And now comes the Tesla S, with a battery that contains enough energy to heat (!) one of these passive houses like the one in Seattle for two weeks. That car will soon have a feed-back-to-grid option. No more need to buy expensive generators for people in disaster areas, just buy a Tesla. The more one steps back to look at the bigger picture, the more incredible it gets that people would still be buying gas cars in this year A.D.2014 that we are in. Wait, 100k is expensive for an aluminum car that won't break, and will probably last 30 or 40 years? Do the math and don't forget the cost for gas, duh. And yes do include a new battery every ten years, guess what the price for that will be doing... At the Intersolar Trade Fair in Munich, Germany, there were more than 200 companies last year offering all kinds of different industrial battery solutions, at an incredible variety of technologies. Polymer batteries, flow batteries, weird stuff I had no idea it could be done. Holy moly, things are really starting to move. Wood furniture factories using waste to power themselves and generate additional income by selling excess power back to the grid! Oups. And as investors know, the smart money has long pulled out from nuclear and oil. Bye, bye, it was nice meeting you.
Kolton Wilson
This really is the dumbest thing that I have ever read! This will be the first thing targeted in the event of a war. I read that Russia is building a floating nuclear reactor too... *sigh*
Daishi
Kirk Sorensen gave a good TED talk about Thorium and he also covers some of the flaws with current reactors here: https://www.youtube.com/watch?v=N2vzotsvvkw It wasn't really the Tsunami that caused the meltdown of the Fukushima reactor, they lost power and then Tsunami put their generators under water causing a full loss of electricity need to cool the reactor. Being hit by a Tsunami in the middle of the ocean may not be likely but a loss of electricity still could happen for various reasons. As Kirk pointed out, reactors are pressure vessels that run at 70 to 100 atmospheres of pressure with 20 cm thick steel walls. If there is a breach that 300 degree celsius (~600 F) hot water expands to become steam and steam needs a very large container to expand into so you need a large thick structure. Taking that structure and placing it in the ocean would not prevent a meltdown within it in the event of a power loss, it would only cause it to melt down away form a populated area but it would still make a mess of the ocean water. Because a loss of electricity = 100% chance of meltdown a floating reactor could still be in danger of something going wrong. If the hot water becomes steam and there is a hydrogen explosion the employees living on top of the thing might not last long either so might be policy to completely evacuate the platform at the first sign of trouble.
BombR76
And you think it is hard to get wind turbines placed offshore? This is a great idea! Wait for the enviro-wackos to shut it down! Thorium Fuel is the future of nuclear power, and safe too.
Daishi
@BeWalt I think the return on investment for a home going solar still depends heavily on tax subsidies and there are still other factors like home owner maintenance that is more of a hassle than simply using the grid. From this link it looks like solar is still a pretty expensive source for power: http://en.wikipedia.org/wiki/Cost_of_electricity_by_source Even mega companies like Apple, Google, and Facebook don't have the same kind of money to throw around as energy companies. Some of the wealthy people in oil in Abu Dhabi or Saudi Arabia couldn't have more money if they were printing it. The $50 million salaries of some CEO's is like an expensive weekend for some of the people who control oil. I wish Tesla all the luck with getting cars to electric. Getting the grid on clean energy is probably an easier problem than getting automobiles there.
MBadgero
Thorium is not used in nuclear reactors because thorium reactors cannot be easily converted for nuclear weapons production, and the countries that have nuclear power want to reserve this as an option.
RelayerM31
One of these babies is just begging for a terrorist to float a submersible drone right next to it and blow it to smithereens. No thanks.