| Popis: |
In the routine maintenance of piping systems in power plants, maintenance management priorities are determined based on quantitative indicators, such as safety classification guidelines and probabilistic risk assessments, as well as qualitative metrics, such as supply reliability, operating experience, and work safety. In power plants, quantifying the level of maintenance criticality for areas that pose little risk to safety is difficult. Assuming damage to the piping system due to deterioration, the internal fluid flowing to the surrounding area may affect the functions of the peripheral equipment and work safety at the site. If the fluid temperature is high, the risk of burning increases. This study was aimed at quantifying the indicators of human burns that may pose a risk to work safety. Based on indicators related to the severity of human burns, we constructed an evaluation model using the results of fluid experiments and analysis of heat conduction in the skin to estimate the PBI, which in turn can be used to estimate the prognosis of burns. It was found that, especially under the condition for the evaluation of flashing, when a phase change occurs before and after a leak, the fluid diffusion range is large, and the fluid temperature is also high near the leak source. Such flow conditions can induce serious burns over a wide area. Based on the trends of the indicators related to human burns obtained in this study, we will construct a model to evaluate work safety risks in power plants using design information like temperature, pressure, and piping layout of the system. |
