The Application Of Human Error Analysis To Risk Assessment For A Submarine

Based on theories and methodologies relevant to generic risk assessment, in combination with Human Reliability Analysis (HRA) method, this paper presents the procedure of risk assessment for a nuclear-powered submarine. Among all potential hazards fire risk and loss of coolant accident (LOCA) are identified as two major accident scenarios, for being events of frequent occurrence and disastrous effects on the submarine itself and the crew. As for the risk events mentioned above, appropriately employed are two methods, Technique for Human Error Rate Prediction (THERP) and Human Cognition Reliability (HCR), for their overriding role in predicting operators'performance reliability and cognitive reliability, respectively.This paper starts with the advance in relevant research areas, as well as generic approaches employed by scholars around the world. What ensues is the discussion of such fundamental theories as human reliability analysis (HRA), risk assessment for fire hazard and risk assessment for nuclear facilities. In the frame of HRA, risk assessment for fire hazard is preceded by virtue of THERP. The major task embraces: the identification of hazardous substance, the application of Gustav Purt method to measure fire criticality of all cabins, the probability computation based on human reliability event tree and the evaluation of general risk. As for risk analysis for nuclear facilities, the work is made in a similar way; however, HCR is employed as a solution to assess operators'cognitive reliability. At the heart of the whole analysis is the human reliability event tree which should draw analysts'attention to its construction, PSFs modification and correlation modification.Aside from theoretical analysis, a program is developed as a highly efficient assistance in figuring out minimum cut sets for fault trees, the top events of which are just the initiating events of two identified accident scenarios. Then the fault trees are built downward, in accordance with logical sequence, with all possible events leading to the occurrence of top events.Finally presented is a case study of a nuclear-powered submarine made in former Soviet Union. The results of this case study indicate the effects of human factors on lifelong service of the submarine and provide human error data.