Deep sea fission

20 January 2011

Global moves to deploy small reactors have led to a new concept unveiled today by France's DCNS - a small offshore nuclear power plant called Flexblue. 


Akin to the submarines that DCNS has been making for the French navy for 40 years, Flexblue is a cylindrical unit 100 metres in length and 12 to 15 metres in diameter. Inside would be a small nuclear power reactor and well as steam generators, turbines and a generator to produce 50 to 250 MWe.


Flexblue (DCNS)
We need to go deeper


The vision is for such a unit to be installed on the seabed under 60 to 100 metres of water, several kilometres from a centre of power demand such as a city, industrial base or remote community which it would serve via underwater cables.


A video released today depicts the unit's deployment under naval guard. It is transported to sea on a heavy lift ship which lowers itself to allow Flexblue to maneuvre under its own power. Descent occurs under the watch of divers before a cutaway view reveals four stories of plant within the hull. The structure is then covered by a net and power is transmitted by cable to shore.


DCNS said it had been working on the Flexblue concept for over two years. It said that both Electricité de France and Areva had "expressed interest in Flexblue's modularity and standardisation." The three companies as well as the CEA are now to begin the next two-year phase of development. Areva-TA already works with DCNS to make small reactors for the French navy.


Awaiting further attention are technical and production options, market potential, competitiveness analyses, proliferation studies as well as safety and security. DCNS wants to demonstrate Flexblue to have a level of safety comparable to Generation-III reactors.


Today's mainstream nuclear power plants produce 600-1200 MWe, while the largest new units reach about 1700 MWe. These are in demand to supply the large grids of advanced economies, but a market is emerging for much smaller units. These could be factory-built, transported whole to the place of use and returned complete with used fuel for management by the vendor.


An offshore nuclear power plant is mid-construction at a shipyard in Saint Petersburg, Russia and destined to power Vilyuchinsk in the country's far east. This is a surface vessel named the Akademik Lomonosov that would host two small reactors based on submarine units and transmit 64 MWe via a purpose-built jetty.


There are also moves to demonstrate land-based small reactors in the USA. Tennessee Valley Authority is considering Babcock & Wilcox's mPower unit for the Clinch River site, while the Department of Energy's Savannah River Site could host a range of small units including Hyperion and GE-Hitachi's Prism.
Researched and written
by World Nuclear News