Complex sentence: The work on such projects dates back to MH-1A, which was built in the 1960s into the hull of a World War II Liberty Ship; however, the Rosatom project is the first mass-produced floating nuclear power plant.
Split into simpler sentences: The work on such projects dates back to MH-1A, which was built in the 1960s into the hull of a World War II Liberty Ship. However Rosatom project is the first mass-produced floating nuclear power plant.