The purpose of this paper is to clarify the overall and local leakage rates of marine reactor safety vessel, establish the acceptance criteria of sealing test for reactor safety vessel and analyze the concentration of airborne radioactive material in surrounding cabins.

Based on the sealing test standard of land-based nuclear power plants, a study on index allocation and calculation of leakage rate as well as feasibility analysis of floating nuclear power plants (FNPP) are carried out in accordance with the general procedure of "standard analysis-indices proposing-indices verification".

The results show that the proposed overall leakage rate of the reactor safety vessel of FNPP is about 3‰/24 h, and the leakage rate distribution of the penetrators of B & C types account for 10% and 50% of the overall leakage rate respectively under design basis accident conditions. During the sealing test, the overall leakage rate of the reactor safety vessel should be considered at 25% of the design margin.

The calculated leakage rate of FNPP meet the requirements of the index and the design margin is desirable, which is of great reference value for the establishment of containment sealing test acceptance criteria.