Integrated Engineering Approach to Safety, Reliability, Risk Management and Human Factors

Abstract

Nuclear industry has important engineering legacies to share with the conventional industry. As a result of nuclear accidents at Three Mile Island, Chernobyl, and Fukushima, many countries have incorporated new steps into the licensing processes of Nuclear Power Plants (NPP), in order to manage accident risks. Probabilistic Safety Analysis has been used for improving safety, reliability and availability in the design and operation of NPP. Despite the close association between these subjects, there are some important different approaches. The reliability engineering approach uses several principles and criteria to minimize the component failures. These include, for instance, redundancy, diversity, and standby systems. System safety is primarily concerned with risk management, that is, the evaluation and control of hazards, which requires the assessment of interactions among system components. Events that cause accidents can be complex combinations of component or instrumentation failures, faulty maintenance, design errors, or human actions. Then, system safety deals with a broader spectrum of risk management, including human factors (ergonomics), licensing requirements, and quality control. Taking care of these topics individually can compromise the completeness of the analysis and the measures associated to risk reduction, and increasing safety and reliability. This chapter presents an integrated framework for analyzing engineering systems, operational procedures, and the human factors based on the application of systems theory. An application example assessing safety, reliability, risk, and human factors issues related to a complex task of Non-destructive Inspection of piping segments of a primary circuit of a NPP shows the benefits of using the proposed integrated approach.