This TECDOC provides guidance for Member States planning to expand their nuclear power programmes through the deployment of advanced nuclear power plants (NPPs). It also provides key information for newcomer countries embarking on their first NPP projects, including those adopting advanced NPP technology. It outlines practical steps for site selection and characterization and considers the application of a graded approach for advanced NPPs. The publication outlines key activities at each stage of the site survey and evaluation process, with a focus on optimizing data collection. It offers a tailored approach to site characterization based on the radiological hazard categories of these installations, reflecting the advanced safety features and robust designs. It also introduces a methodology for radiological hazard categorization based on consequence analysis, followed by practical guidance for grading site investigations, particularly seismic and geotechnical hazards, which are resource intensive.