A new design for nuclear plants built on floating platforms, modeled after those used in the offshore oil and gas industry, has been created by professors at Massachusetts Institute of Technology (MIT).
They say such a design could help avoid the disaster at Fukushima Daiichi nuclear plant, Japan, in 2011, by using the seawater the unit sits in to cool the reactor cores in the event of an accident.
The floating nuclear plant concept is not new. Russian firms are building a barge-mounted prototype, the Akademik Lomonosov, which would be moored to shore and is meant to be the first vessel in a new Russian fleet of floating nuclear power plants.
Illustration courtesy of Jake Jurewicz/MIT-NSE: Shows a possible configuration of a floating offshore nuclear plant, based on design work by Jacopo Buongiorno and others at MIT's Department of Nuclear Science and Engineering.
Like offshore oil drilling platforms, the structure would include living quarters and a helipad for transportation to the site.
The MIT concept was presented last week at the Small Modular Reactors Symposium, in Washington, hosted by the American Society of Mechanical Engineers, by MIT professors Jacopo Buongiorno, Michael Golay, and Neil Todreas, along with others from MIT, the University of Wisconsin, and Chicago Bridge and Iron (CB&I), a major nuclear plant and offshore platform construction company.
“When an earthquake and tsunami struck [Fukushima], neither the quake nor the inundation caused the ensuing contamination. Rather, it was the after-effects — specifically, the lack of cooling for the reactor cores, due to a shutdown of all power at the station — that caused most of the harm,” says MIT.
The MIT design would be designed to be automatically cooled by the surrounding seawater in a worst-case scenario, which would indefinitely prevent any melting of fuel rods, or escape of radioactive material, says MIT.
Professor Buongiorno, an associate professor of nuclear science and engineering (NSE) at MIT, says floating plants could be built in a shipyard, then towed to their destinations, 5-7 miles offshore, where they would be moored to the seafloor in about 100m water depth and connected to land by an underwater electric transmission line.
In 100m water depth it would be unaffected by the motions of a tsunami; earthquakes would have no direct effect at all, MIT says.
Biongionro says mooring at shore would not be far enough offshore to be able to ride out a tsunami, although the Akademik Lomonosov designers say their unit would withstand tsunamis and tornados.
The concept uses two mature technologies: light-water nuclear reactors and offshore oil and gas drilling platforms. Using established designs minimizes technological risks, says Buongiorno.
Other advantages are the increasing difficultly and cost of finding suitable sites for new nuclear plants, and ability to decommission by towing it away to a central facility, as is done for the Navy’s carrier and submarine reactors. Plant design could be anywhere from small, 50-megawatt plants to 1000-megawatt plants.
Buongiorno sees a market for such plants in Asia, which has a combination of high tsunami risks and a rapidly growing need for new power sources. “It would make a lot of sense for Japan,” he says, as well as places such as Indonesia, Chile, and Africa.
This is a “very attractive and promising proposal,” says Toru Obara, a professor at the Research Laboratory for Nuclear Reactors at the Tokyo Institute of Technology who was not involved in the research. “I think this is technically very feasible. ... Of course, further study is needed to realize the concept, but the authors have the answers to each question and the answers are realistic.”
The paper was co-authored by NSE students Angelo Briccetti, Jake Jurewicz, and Vincent Kindfuller; Michael Corradini of the University of Wisconsin; and Daniel Fadel, Ganesh Srinivasan, Ryan Hannink, and Alan Crowle of Chicago Bridge and Iron, based in Canton, Mass.
The Akademik Lomonosov is a pilot design of the set of small transportable power plants. JSC Afrikantov OKBM is the designer.
According to World Nuclear News, Akademik Lomonosov will be deployed at Vilyuchinsk, in the Kamchatka region in Russia's Far East, and is expected to be delivered in 2016.
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