## 3 Results
### Determination of Emergency Scenarios  
The determination of the worst-case situation in which the greatest number of people are at risk and the environment is at greatest risk from the effects of an explosion, toxicity or fire of the released fuel is based on the estimation and determination of emergency scenarios. The selection of possible accident scenarios was based on:  
* the expected release of the maximum quantity of each hazardous substance,
* the largest area of a fire,
* the possible danger to the surroundings from an explosion and radiant heat,
* the number of persons at risk on the premises [41]. The types of hazardous substances, their fire-technical characteristics, their handling, the technological process of production, fire protection, and protection systems have a considerable influence on the determination of emergency scenarios [42]. In the gas station facility, the following possibilities of emergency leakage of oil from the storage and handling areas have been identified as significant. Realistic cases where fuel spills may occur are listed in Table 5. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Equipment** & **Volume [m3]** & **Technological Process** & **Hazardous Substance** \\ \hline car tank & 45 & transfer of fuel to storage tanks & gasoline, diesel \\ \hline storage tank & 55 & fuel storage & gasoline, diesel \\ \hline connecting pipe & - & transportation of fuel from storage tanks to fuel stands & gasoline, diesel \\ \hline stand dispensing gun & - & delivery of fuel to vehicles & gasoline, diesel \\ \hline LPG tank 1 & 50 & transfer of LPG to storage tanks & LPG \\ \hline LPG tank 2 & 4.8 & LPG storage & LPG \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Internal sources of danger. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Emergency Scenario** & **Type of Leak** & **Cause of Leak** \\ \hline  & one-time leakage of the entire transported amount & damage of the tank shell \\ \cline{2-3}
1. fuel leakage during filling & & rupture of the dispensing hose, or its incorrect installation at the connections with the dispensing pipe or tank \\ \cline{2-3}
2. leakage of fuel from storage tanks & continuous leakage & overflow of the tanks \\ \hline
3. fuel leakage from the connecting pipe & continuous leakage & or leakage of the transport pipe \\ \hline
4. leakage of fuel from fuel stands during refueling & continuous leakage & damage to the fuel stand or fuel guns when refueling fuel into vehicles \\ \hline
5. leakage of LPG from the tank & one-time leakage & damage to the safety valve, damage to the integrity of the reservoir shell when a car hits the reservoir, corrosion \\ \hline  & one-time leakage of the entire transported amount & damage of the tank shell \\ \cline{2-3}
6. LPG leakage during filling & continuous leakage of transported LPG & rupture of the dispensing hose, or its incorrect installation at the connections with the dispensing pipe or tank \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Emergency scenarios. The initiation and subsequent fire or explosion of the underground fuel storage tanks is considered as an unlikely emergency scenario under standard operating conditions and in a peaceful state. Damage to the underground fuel storage tanks is only realistic in the event of an aircraft crash on the area of the fuel storage facility and in a state of war [43]. Consequences of potential accidents modelled only for selected emergency scenarios:  
* scenario 1 leakage of the entire quantity of gasoline from a tanker during filling,
* scenario 5 leakage of the entire quantity of LPG from the storage tank,
* scenario 6 leakage of the entire quantity of LPG from a tanker during filling. The selected emergency scenarios were modeled in two basic representative weather classes:  
* normal air stability, class 4 = D, wind speed medium-5 m\(\cdot\)s\({}^{-1}\) (the most common conditions during the year),
* very stable conditions, class 1 = F, wind speed low-1.7 m\(\cdot\)s\({}^{-1}\) (worst dispersion, largest area affected-worst case scenario).