ABSTRACT
This chapter is concerned with the estimation and reduction of human error in systems. It describes the risk assessment process, identifying Human Reliability Assessment (HRA) inputs as this process. The chapter considers the HRA at a fairly high level in terms of its interface with the probabilistic safety assessment (PSA), before proceeding into the more detailed aspects of the HRA techniques themselves. It also considers the various stages of the Human Reliability Assessment process plus the techniques available for achieving each stage's objectives. The PSA involves the evaluation of conceivable risks to worker and public safety, and in some cases the risk of damage to the plant and the environment. The PSA identifies ways in which hazards can occur, during system operation and maintenance, which can lead to undesirable events. The PSA then calculates the probabilities and frequencies of such events, determines their consequences and compares the summarized risks estimated against industry/regulatory criteria.
