China has ambitious plans to build a fleet of 20 floating nuclear reactors
Russia is already building a floating nuclear power plant
But storms, waves, maintenance all pose safety concerns
Editor’s Note: Tony Roulstone established and teaches on the nuclear energy masters program at the University of Cambridge, with research interests in the economics and safety of nuclear power. He is a visiting Professor of Nuclear Engineering at City University in Hong Kong. The views expressed here are solely his.
China is planning to build nuclear reactors that will take to the sea to provide power in remote locations, possibly including the controversial man-made islands in the contested waters of the South China Sea.
These small power plants will be built in Chinese shipyards, mounted on large sea-going barges, towed to a remote place where power is needed and connected to the local power grid, or perhaps oil rig.
After pausing its nuclear program after the Fukushima disaster in Japan in 2011, China has since committed to a huge clean energy drive of wind, solar and nuclear generation, each as big as any in the world.
The ambitious 2016 nuclear plan, formalized in China’s 13th five-year plan in March, includes completing 58 power reactors by 2020 and building perhaps another 100 gigawatt-sized reactors by 2030, when China would become the largest nuclear power producer in the world.
As part of this plan China is going to build up to 20 floating nuclear plants.
The plans have raised eyebrows and many are asking: Why are they being planned? Will they be safe? Will they be economic?
Where Russia leads
This idea is not new.
In 1966, the U.S. mounted a submarine nuclear power plant on the Liberty ship, Sturgis, to power the Panama Canal Zone from 1968 to 1975.
Now Russia is building floating nuclear plants with reactors taken from their nuclear powered icebreaker program. The first of these plants is being built in a shipyard in St Petersburg.
It has two 35 MW nuclear power plants, is 144m long and will have a crew of 69. The barge will be towed through the Baltic and Arctic seas, to sites in Siberia to power Gazprom, or military facilities.
Seven floating nuclear power plants are planned by Russia. The first, the Akademik Lomonosov, should be completed this year at the high cost of $740m, according to World Nuclear News.
It is destined for the Far East port of Pevek, in the Chukotka Republic of Kamchatka.
But China’s plans are much more ambitious.
Construction of the first demonstration floating power plant is to start in 2017, with electricity generation to begin in 2020. The first plant of 20 that are planned may be destined for a site on Hainan Island in Southern China.
China National Nuclear Company has been touring industry conferences for more than year explaining their small reactors and their applications and I visited the company in 2013.
Reports suggest that oil and gas company China National Offshore Oil Corporation (CNOOC) is expected to use floating nuclear power plants for offshore exploration in the South China Sea.
Also, it has been reported that these floating nuclear power plants are being considered for remote locations in the South China Sea, where China has been building man-made islands that are at the heart of disputes over ownership of what is expected to be oil-rich waters.
China is using small modular reactors of 50 or 100MW in output, designed for alternative nuclear applications: industrial steam supply, desalination, district heating and remote power supplies.
These small reactors are similar to ones being considered in U.S. and Europe as an alternative to the large reactors, which are the norm for power generation.
They use the same proven water reactor technology as their larger cousins, but are small enough for much of plant to be built in factories, where costs are potentially much lower.
Many of these reactor designs have all the main components inside a single large reactor vessel.
In the case of the Chinese design, the pumps are mounted on the outside of the reactors, with the steam generators and the reactor core inside the vessel.
Safe on the seas
This type of integral design is thought by some to be safer because it can reduce or eliminate one of the key safety risks, a loss of coolant accident.
If there are no large pipes and no valves the number of possible leak sites is cut.
Some small reactor designs make very strong claims for improved safety based on their low power density and passive means of removing core heat after shutdown.
These claims have yet to be tested by the challenges from an experienced nuclear safety regulator.
In the Chinese design for the floating plant, the reactor and turbines are mounted deep inside a sea-going large barge.
All the safety systems found in a land-based power plant are included, including importantly a leak-proof reactor containment around the nuclear systems,
While the barge can provide similar safety systems there many are questions whether these reactors will be safe on the seas.
They will be exposed to the vagaries and the uncertainties known by seafarers and to extreme storms and waves – sinking of the barge is a possibility.
Also, it could be harder to protect seaborne reactors – opposed to their land-based counterparts – from external threats such as the loss of off-site power or a terrorist attack.
Maintenance, key to safe operation, will be much more difficult in remote locations. These are new and different hazards from those considered for land-based reactors.
The crucial issues of flooding for nuclear reactors and the loss of power required for cooling were highlighted by the accident at Fukushima.
While the Chinese regulators may use the same safety standards as elsewhere in the world, their process is not sufficiently transparent for outsiders to be clear whether, or not, these novel floating nuclear power plants can be made as safe as modern land-based reactors.