Root Cause Analysis in Support of Event Investigation

Abstract

Reliability based methods are widely used for the safety assessment of plant system, structures and components. These methods provide a quantitative estimation of system reliability but do not provide insight into the failure mechanisms. Understanding the failure mechanisms is a must to avoid the recurrence of the events and enhancement of the system reliability. Root Cause Analysis (RCA) provides a tool for gaining detailed insights into the causes of failure of a component with particular attention to the identification of fault in component design, operation, surveillance, maintenance, training, procedures and policies which must be improved to prevent repetition of events. Dhruva is a 100 MWth research reactor located at Bhabha Atomic Research Centre, Mumbai. In this research reactor, each failure/malfunction in SSCs or human error, termed as an ‘Event’ is reported by plant Operations and discussed in plant safety committee. Depending upon the importance of the events to the safety of the plant, RCA team of experts in various disciplines analyzes the events. This paper discusses the methodologies adopted for performing RCA of different events in Dhruva reactor.