Nuclear power plants are exposed to a variety of hazards, which may result in risks (the product of the likelihood of the hazard and resulting consequence). One of the key objectives of the NARSIS project is to improve the integration of external hazards and their consequences with existing state-of-the-art risk assessment methodologies in the industry. Accordingly, the main goals of this deliverable are to: - Review the various aspects of risk integration and associated methodologies - Review case histories of accidents in complex industrial set-ups, both nuclear and non-nuclear, and highlight prevalent ‘latent weaknesses’ that eventually led to these accidents - Review deterministic and probabilistic methods to identify latent weaknesses - Review risk integration methods currently used in high-risk industries such as nuclear, chemical and aviation - Review accident investigation procedures and international initiatives associated with major nuclear accidents - Discuss specific risk integration method(s) that are relevant to the NARSIS project@en