Most of the money has come from 13 Japanese companies including Onomichi Dockyard and Imabari Shipbuilding.
Core Power is collaborating in a $600 million development programme with TerraPower of the US, backed by Bill Gates, Southern Company of the U.S and Orano of France.
Floating nuclear power plants are smaller, more efficient, safer and less expensive than on-shore plants and are unaffected by earthquakes.
