In order to solve the serious problem of marine biofouling on coarse grids in the CFI (circulating water filtration) system of a certain nuclear power plant, the operation conditions of the coarse grid, the reasons for marine biofouling and the existing anti - fouling measures were analyzed. It was found that tin - free self - polishing anti - fouling paint and sodium hypochlorite biocide did not have a decontamination effect. Therefore, the non - toxic, non - sticky pure organosilicon anti - fouling paint was used as the new coating to restrain marine biofouling together with modified NaClO dosing equipment. The verification showed good effect was obtained: there was basically no visible sea creatures attachment on the surface, the coating was basically intact, and the loss rate of the anti - fouling paint was low. This method could ensure the continuous operation of the coarse grid for a long time, which would provide reference for the follow - up power station coarse grid to prevent sea biofouling
