Abstract: The floating nuclear power plant (FNPP) is a nuclear power plant located in sea area; and the main radiation source is concentrated in the cabin area. Inside the bulkhead is a ship cabin containing radiation sources such as reactors and primary circuit systems. The outer space of the reactor compartment includes side and the bottom of the ship. The radiation zone inside the bulkhead is similar to that of onshore nuclear power plant, while the outer space requires additional consideration. For the FNPP’s radiation zoning standard selection, the design method of the onshore nuclear power plant can be referred to the reactor compartment, but the reference area is lacking in the area outside. In this paper, the general characteristics of the FNPP’s radiation are given. The constraints affecting the radiation zone outside are studied. The solution for the design of the side and bottom’s radiation zoning is given, taking into account the radiation safety, high radiation area management costs and economic cost. The results can be as engineering design reference.

Key words: FNPP, reactor compartment, radiation zoning, shielding