Los reactores nucleares funcionan bajo algunas de las condiciones más extremas encontradas en la ingeniería industrial, combinando flujos de radiación intensos con refrigerantes corrosivos y altas temperaturas.Los materiales estructurales utilizados en núcleos de reactores, sistemas de refrigeración primaria y estructuras de contención deben mantener la integridad durante décadas de servicio. Los recubrimientos protectores son una línea crítica de defensa, blindando componentes de degradación que podrían comprometer la seguridad, aumentar los costes de mantenimiento o acortar la vida de plantas.

El entorno del reactor nuclear: un entorno de demanda para materiales

To appreciate the role of coatings, one must first understand the aggressive conditions inside a nuclear reactor. The primary coolant loop—whether light water, heavy water, or liquid sodium—carries heat away from the fuel assemblies but also promotes corrosion of metal surfaces. In water-cooled reactors, radiolysis produces oxidizing species like hydrogen peroxide, which accelerate general and localized corrosion. In sodium-cooled fast reactors, oxygen impurities and mass transport effects can cause corrosion and carburization. Meanwhile, high-energy neutron and gamma radiation induce displacement damage and transmutation within coating and substrate materials, altering their mechanical and chemical properties. Temperatures in pressurized water reactors (PWRs) reach around 320 °C, while in boiling water reactors (BWRs) they are slightly lower but still aggressive. Advanced reactors, such as very high-temperature reactors (VHTRs), push toward 900–1000 °C. The combination of thermal stress, radiation, and chemical attack demands coatings that can adhere firmly, maintain chemical stability, and self-