Renovation of inner coating in tank and application of new protection system at Vandellós II NPP

During the last refuelling outage of Spanish nuclear power plants, GDES performed a large number of unique and specialist tasks. One such operation was undertaken by the GDES Revanti team at the Vandellós II nuclear power plant on the renovation of the inner coating of one of its tanks (APT01).

The tank is a vertical cylindrical atmospheric tank with metal plates on its base, shell and roof, with a working volume of 1,700 m3.

The Ascó Vandellós II Nuclear Association awarded our specialist surface treatment team the contract to remove the coating and apply a new protection system during R26 in 2024 in accordance with ET-SGM-V-069.

Over 9 days Revanti’s site manager at Vandellós II, applied an inner coating to the tank with a surface area of more than 1000 m2. This coating will prevent oxidation and internal corrosion processes, ensuring its continued use as a storage element for the long-term operation of the plant.

The process involved an initial cleaning and vacuuming of the walls and floor of the empty tank, and the assembly of a complete scaffolding structure inside the tank with access to the entire surface with a maximum distance of 50 cm. These activities were carried out by GDES, another of the companies belonging to the Dominguis Group.

This was followed by abrasive blasting until the existing coating was completely removed and surface preparation grade Sa 3 was obtained. 50 Tn of blast media extracted by means of a suction truck with turbines. Surface cleaned with vacuum and compressed air to remove dust and foreign matter. And the application of a 450 – 500 micron protection system consisting of an anti- corrosive epoxy primer base and a two-component amine-cured epoxy coating.

This ensures that the tank receives an inner coating suitable for long-term storage of demineralised water, meeting the requirements of A-150-C Surface Preparation and Coating Application as well as PGE-026 Life Management for the long-term operation of Vandellós II NPP.

Congratulations to all the colleagues who participated in the process. Here are some interesting images of the application process.

Structure and scaffolding

Roof Treatment

Detail of floor finish