Floating Nuclear Reactors Might Make More Sense Than You'd Think

By Kelsey Campbell-Dollaghan on at

At a symposium held by the American Society of Mechanical Engineers this week, a team of MIT engineers will present an idea that seems to tempt fate: A floating nuclear reactor, anchored out at sea, that would be immune to tsunamis and earthquakes. Is it really that crazy of a plan?

First, here's what they're proposing. MIT professors Jacopo Buongiorno, Michael Golay, and Neil Todreas are the authors of a paper that describes a massive reactor that's built in a shipyard, then towed out to sea like an oil platform. A few miles off the coast, the reactor would be anchored in a single spot, feeding the power it produces back to the cities on the shore.

Russia is already building a floating reactor, as Buongiorno points out, but there are some key differences that he says gives their plan "crucial advantages." First, MIT's design isn't so much a ship that moves around but an anchored platform, which means it's never in a situation where a tsunami or earthquake could affect it.

Second, and most important, is the cold ocean water that would surround the reactor. All those billions of tonnes of seawater will act as an endless source of cooling for the internal rods, ensuring that they never, ever overheat.

"The ocean itself can be used as an infinite heatsink," says Buongiorno. "It's possible to do cooling passively, with no intervention. The reactor containment itself is essentially underwater."

Floating Nuclear Reactors Might Make More Sense Than You'd Think

Another important part of the design is how it would lessen the dangers of decommissioning the plant in fifty years: Rather than undertaking the long, slow process of removing the rods and demolishing the plant, it would be towed "to a central facility, as is done now for the Navy's carrier and submarine reactors." If a meltdown occurred, the plant could "vent radioactive gasses underwater" rather than releasing them into the atmosphere and forcing millions to evacuate.

Wouldn't releasing radioactive gasses underwater also be pretty terrible, environmentally? Why not just stop building nuclear power plants altogether? That's not really the question these engineers set out to answer. This is about making the plants, whether or not countries chose to build them, safer.

But it's hard to ignore the extraordinary moral implications of that particular detail. Given the choice between spraying humans with radioactive fumes and spraying the ocean floor, most of us would probably choose the latter. It's tough to argue with that, but it's also tough to endorse it. [MIT]