Supervisors info:
Εξειδικευμένη Επιστημονική Καθοδήγηση: Γ. Μουζάκης Χημικός Μηχανικός - ΥΠΕN / Διεύθυνση Περιβαλλοντικής Αδειοδότησης
Τριμελής Εξεταστική Επιτροπή:
Δρ. Σ. Λόζιος, Επικ. Καθηγ. ΕΚΠΑ
Δρ. Β. Αντωνίου, Δρ. Γεωλόγος, Ε.Δ.Ι.Π. ΕΚΠΑ
Δρ. Ε. Βασιλάκης, Επικ. Καθηγ. ΕΚΠΑ
Original Title:
Συγκριτική αξιολόγηση αποτελεσμάτων Εκτίμησης Βιομηχανικού Κινδύνου με τη χρήση υπολογιστικού μοντέλου εκτίμησης επιπτώσεων και αποτελεσμάτων που προέκυψαν στο παρελθόν σε βιομηχανίες, παγκοσμίως. Αποκλίσεις μεταξύ θεωρητικών και πραγματικών τιμών.
Summary:
Diploma thesis deals with: "Comparative Evaluation between Industrial Risk Assessment computational model results and impacts caused in Industries in the past, worldwide. Deviations between theoretical and factual values" in order the effectiveness of the ALOHA-Marplot model to be estimated, as an assessment tool. The evaluation is based on the theoretical design relating to existing impact data coming through industrial accidents that happened in the past.
At the beginning a literature review was realized according the theoretical background related to the accuracy of the ALOHA-Marplot model results and possible deviations between model's calculations and real impact conditions. In the next step a contribution of disaster impact assessment models to the Industrial Risk Assessment and the requirements of the Seveso III Directive (2012/18 / EU) was examined. The literature review of the most characteristic case studies of industrial accidents (reported in scientific publications, databases, etc.) was presented, such as the accidents impact zones defined. The literature review has been extended to the relevant literature dealing accuracy of the ALOHA-Marplot model results and possible deviations of the model's results compared to the factual accidents impacts.
Based on the significance of the impacts and the availability of the data, examined the comparative evaluation of the accidents impacts between five different accident case studies, one for a BLEEVE explosion, one for Flash-fire case study, one for vapor cloud explosion (UVCE) and two cases for leakage of hazardous substances.
Regarding the main part of the thesis, the evaluation methodology was initially defined. Additionally, based on the literature data and assumptions, the simulated estimation of Industrial Risk Impact Areas was realized using ALOHA-Marplot model using the input data of the factual Industrial Accident results. These data are related to:
• the quantities and characteristics of the chemicals or gases that caused the accident,
• meteorological parameters and topography of the accident area per case (from meteorological databases, etc).
In a second phase the results of the model were grouped on a case-by-case basis and presented in a comparison with the factual accident data in a graphically and quantitatively comparison. Due the comparison of these results, the comparative evaluation of the Industrial Risk Assessment theoretical and factual results was carried out. In the evaluation carried out, the relevant available literature was the basic source for extracting conclusions about the range of the high risk zone within which the most significant impacts occurred. Accordingly, based on the calculation data obtained from the literature, the implementation of the ALOHA model led to the calculation of the high-risk zone.
Both the numerical and graphical comparison of the exported values resulted in the following conclusions:
• In cases where the model exported an over-dimensioning radius of the critical zone compared with the factual value, it cannot considered as a "failure" of the model. It is crucial to take into account the fact that ALOHA is a stochastic model that can provide a safe approach to the industrial accidents impact modeling. In any case this deviation is in favor of security since it defines an expanded distance in which the range of the zone could create a safe evacuation zone.
• There were also cases where the model almost matches perfectly the radius of the critical zone between the theoretical and the factual value.
• As a general conclusion, it can be assumed that as a decision-making tool, ALOHA could provide a quick and safe assessment of the evacuation zone before the explosion occurred.
In any case, the existence of a relevant Risk Assessment Report supported by the implementation of risk assessment models notified to the local authorities could possibly provide information to the Head Coordinators in order to reduce the possibility of human losses and achieved better efficiency in emergency actions and planning of effective civil protection plans (evacuation plans, firefighting plans, etc.).
Keywords:
ALOHA-Marplot, Seveso ΙΙΙ, ALOHA-Marplot, Seveso III, industrial accidents, industrial risk assessment, exclusion zones, comparative Evaluation.
