Statistical analysis of components failures based in the operational incident annual reports - the Brazilian case

The performance of the Brazilian Power Plant CNAAA-I (ANGRA-I) has been extremely irregular since the initial criticality in March of 1982. The construction and commissioning were concluded in the period from 1971 to 1982. This study shows in a statistical sense where the problems are more critical and gives an evaluation in order to investigate the impact in safety, mainly in those systems related to the safety functions of the plant. The data utilized came from the annual reports sent to the Brazilian Nuclear Energy National Commission (CNEN) by the utility FURNAS, responsible for the ANGRA-I operation. This study has indicated a necessity to create a systematic operational incident investigation system in CNEN to detect the root causes more effectively, including the participation of Human Factors in it. Following this, the study gives recommendations for the fiscalization group to do inspection in those areas where the study points a critical situation. The latter brings the discussion above to the collaboration from safety risk analysis group to determine the systems and components which contribute more for the increase of an accident risk as well as to find the countermeasures to conduct the situation objecting the accomplishment of the safety goals. (author)