Protective coatings at nuclear power plants should be designed to withstand exposure to ambient conditions during normal operation or design-basis accidents. However, there was a change in the perception of the protective coating to the revision of the Regulatory Guidelines by the NRC in July 2000. In other words, maintenance guidelines have been strengthened in order to minimize the clogging of the cooling water system due to the substances in the containment building. Therefore, KHNP, the contractor and operator of the nuclear power plant, plans to develop the coating system for nuclear power plants in accordance with the regulation, and plans to develop its own coating expert.