APP (Análise Preliminar de Perigos) nas manobras de submarinos nucleares em canais de acesso: levantamento de erros humanos a partir de HTA (Hierarchical Task Analysis)

Abstract

Navigation in access channels, although considered more sensitive and dangerous than open- sea navigation, is reasonably common. However, when it comes to a nuclear-powered submarine, the level of concern is elevated due to the more severe consequences in the event of an accident. In this situation, it is imperative to assess all possible human-caused errors. In this study, a qualitative analysis of human activities was conducted using Hierarchical Task Analysis (HTA). Subsequently, a methodology known as Technique for Early Consideration of Human Reliability (TECHR) was applied to help assess the probabilities of various forms of human errors occurring. This way, it is possible to evaluate actions that are natural for humans along with the chances of errors in these actions occurring. With an assessment of the frequency and consequences of human failures, we can determine if they are acceptable and also identify measures to reduce the likelihood of their occurrence. Cases where there is a probability of personal accidents and/or the release of radioactive material can be considered catastrophic. The study aims to make a comparison between hazards generated by human errors and those identified through a Preliminary Hazard Analysis (PHA) in order to mitigate risks that were not considered tolerable. These actions aim to prevent impacts in various areas: environmental, media, financial, material, and most importantly, personal. After completing the entire process described above, four actions were found to be "not tolerable," and five were of "medium tolerance," all of which require risk reduction measures. Given that it is a nuclear-powered submarine with significant implications, the suggested measures for non-tolerable risk actions include increasing redundancies in the verification of navigation steps by more experienced personnel and intensifying training for all stations involved in the process. For errors classified as "medium risk," mitigating measures were proposed. Some of these measures involve increasing the number of people involved in the decision-making process to enhance the chances of identifying potential errors. It was also recommended to seek the guidance of experienced individuals, for example, not entering the channel without the assistance of a professional and external support. This study also concluded that there is a lack of research on human errors in specific situations involving nuclear-powered vessels. Continued discussion of topics related to risk assessment and safety measures in the nuclear field should be strongly encouraged for the benefit of people and the environment. It is reasonable to continue with further in-depth research by other researchers who can take this analysis to a more quantitative and detailed level of specification.