Ohs Risk Assessment – A Case Study for Underground Coal Mining Electricians

Abstract

Risk assessment is a concept introduced for analysing the safety level in workplaces in order to assess if enough and proper precautions have been taken or if their number and quality should be improved so that to prevent hazardous situations. The underground coal mining industry is very hazardous, facing serious fatalities related to work, workplaces and workers as a consequence of the high-risk processes carried out underground and of the hazardous toxic and explosive atmosphere.
 The use of electrical equipment in such hazardous atmospheres (underground or surface) presents a series of particularities, the workers operating this equipment being exposed to electrical injury. The starting point for the optimization of the activity for preventing work accidents and occupational diseases in a system is represented by the risk assessment of that specific system. Regardless if it is a workplace, a workshop or an enterprise, such an analysis allows the ranking of risks depending on their dimension and the efficient allocation of resources for priority measures. Risk assessment involves identifying all risk factors in the analysed system and quantifying their size based on the combination of two parameters: the severity and frequency of the maximum possible consequence on the human body. This results in partial risk levels for each risk factor, respectively global risk levels for the entire system analysed.
 In order to facilitate the fulfilment of the legal obligations of the employers in the field of risk assessment of accidents and occupational disease, a relatively large number of methods have been designed and used. Of the many methods used worldwide for assessing the risk of accidents, within this article is used a risk assessment method developed by a Romanian Institute for Research and Development in Labour Safety Bucharest, the paper dealing with a case study in an underground coal hard coal mine carried out for presenting the practicality of this method, in case of assessing the risks of electrical injury of mining electricians.

Release of overpressures in computational simulations of air-methane explosions

“…Figure 8 b) shows velocity vectors higher than those in Figure 8 a), which means opening the end of the tube (transforming this surface from the Wall into a Pressure Outlet) and release of explosion pressures, [5,6]. This fact is confirmed by the decrease of pressures from the entire volume of the rectangular tube starting with this moment and the tendency of the curves to the value of atmospheric pressure [7].…”

Numerical modelling of hydrogen release and dispersion

“…PHAST is one of the most widely used software for safety engineering applications, many company engineers, competent authorities and other researchers using it for predicting the dispersion of hazardous materials. [10,11,12,13] In this study, the main input parameters involved in the calculation of various model outputs are related to storage, atmospheric, release and orographic conditions.…”

“…For the general public to use hydrogen as a vehicle fuel, they must be able to handle hydrogen with the same degree of confidence as conventional liquid and gaseous fuels. The hazards associated with jet releases from accidental leaks in a vehicle-refuelling environment must be considered if hydrogen is stored and used as a high-pressure gas since a jet release can result in a fire or explosion [13].…”