The possibility of inducing major accident scenarios by physical intentional attacks (e.g. terrorist attacks) to chemical and process plants processing and storing hazardous substances, has been increasingly recognized in the last decades. The identification of the credible security scenarios (chain from attack scenarios to major accident scenarios) is required by Security Vulnerability/Risk Assessment (SVA/SRA) methodologies, but an evident lack of supporting tools is present in the literature. The present study proposes a Bow-Tie approach for the identification of reference security scenarios to support hazard identification phase in SVA/SRA. The potential use of the results is demonstrated on a test case (industrial atmospheric tank storing a flammable liquid).