Power expansion planning is one of the key challenges in power systems management, both in theory and application. Power generation significantly affects society and the environment in several ways, such as greenhouse gas emissions, air and noise pollution, hazardous waste, life-threatening issues and social expectations. These factors become more important in power systems facing hazards and disasters that may result in system disruptions. This paper considers generation expansion planning using a sustainable risk-averse approach that addresses both the socio-environmental factors and the disruption risks involved in a power system. The approach uses a mathematical formulation that can be linearized as a mixed-integer linear programming model. The approach is applied to the case of Iran's southwestern power grid. The computational results demonstrate the importance of incorporating disruption risks and sustainability issues into power systems planning.