I have blogged about the Russian floating nuclear reactor that is being deployed to the Artic to aid oil exploration. Now it appears that the idea of a floating nuclear reactor is becoming more popular.
Construction of a nuclear reactor onsite becomes problematic if the site is in a remote area with harsh weather conditions. If you use a floating reactor in such locations, it can be built in a convenient shipyard near a major port and then moved to the location where it will be used. Ocean water can be used to cool the reactor. When the reactor is no longer needed, it can be moved to a new location. Of course, there are questions about safety.
China has announced that it intends to build about twenty floating nuclear reactors. The first such reactor should be ready for service in 2019. Indonesia is very interested in floating nuclear reactgors because there are many small islands in Indonesia which could benefit from a floating electricity generator.
ThorCon USA Inc. is a private company located in Stevenson, Washington. It is developing the ThorCon small modular reactor based on a design from Oak Ridge National Laboratory. The ThorCon reactor is a molten liquid salt reactor designed to be carried on a barge. They use the same steam conversion system for electricity generation as a five-hundred megawatt supercritical coal plant but without most of the infrastructure required by the coal plant. Ultimately, the ThorCon reactor will generate electricity at about one third the cost of the supercritical coal plant.
The floating ThorCon nuclear plant is called a nuclear island. It requires about one-sixth as much steel and about one-fourth as much concrete upstream from the steam turbine as a coal plant. A one-gigawatt ThorCon nuclear island requires less than four hundred tons of superalloys and other exotic materials. On the nuclear side, it uses about half the steel and about one fifty the concrete of a land based small modular reactor. Because the ThorCon reactor operates at ambient atmospheric pressure, the concrete used to construct it does not have to be reinforced. Reinforced concrete construction is impossible to automate, its requirements drive the critical path, it cannot be used in block construction and, ultimately, encloses the reactor in a solid structure that makes it very hard to repair and replace. The ThorCon reactor can be constructed entirely in bargable blocks in a shipyard assembly line.
It is estimated that the ThorCon nuclear island should be able to produce electricity for under five hundred dollars per kilowatt. This would translate into about seven cents per kilowatt hour for consumers. A big well-equipped shipyard should be able to produce one hundred one gigawatt ThorCon nuclear islands a year.
A one gigawatt ThorCon nuclear island needs about seven thousand pounds of twenty percent Low Enriched Uranium fuel to start. From then on, twenty-four pounds of this fuel must be added every day. Every eight years, the fuel must be changed out completely. One hundred and sixty tons of fuel will be sent to a recycling facility every eight years when the fuel is changed. About twenty four percent of the spent fuel will be uranium with the rest being thorium, If the only processing is boiling off the molten salt and no recovery is carried out, only seventy cubic feet of nuclear waste is produced.
The ThorCon nuclear reactor could be a game changer for energy production along the world’s coastlines.