A Safety-II Approach on Operational Maneuvers of a Hydropower Plant

Abstract

This work investigates, under the Resilience Engineering (RE) approach, the environmental conditions that lead to accidents at the Itaipu Binacional hydroelectric power plant (Itaipu HPP). The socio-technical importance of the installation and the technological update of all control, supervision and monitoring systems in a near future justify the work. The study focused on the impacts of variability in the normal operation of four typical maneuvers representing the four quadrants of a periodicity-complexity matrix, and the variability influencing each step of the maneuvers. The opinions from the operational staff were raised, organized, and the RE principles, techniques and heuristics were applied to them. Although the selected maneuvers might not represent the whole universe of more than five hundred maneuvers executed by the Itaipu HPP, the results indicate that some variability types such as “maneuver environment”, “the need to confirm the maneuver steps with another operator”, “situations that draw attention from the operator”, and “the similarity with another operating environment” act decisively in practically all maneuvers. The operator knowledge was not mapped as a fundamental variability impacting the failures. The results were compared with historical data and presented to the staff, who proposed necessary actions to increase the operational safety under the RE perspective. Overall results imply that there is room for moving from a reactive traditional safety management (Safety-I), based on retrospective analysis of accidents and “what went wrong,” to an effective proactive one (Safety-II), based on the variability of normal operation and therefore “what goes right.”