The course deals with the risk assessment of technical systems, a tool to guarantee safety for personnel and population, environment and asset protection against daily and major accidents, both for process plants and mining installations.

Basically, at the end of the course students will be able to manage properly concepts such as safety, hazard, risk and to approach their future daily professional choices using a risk based approach.
From a technical point of view, they will be able to organise a risk assessment for a complex technical system (oil&gas process systems or mining installations) using the tools presented in this course and collecting their knowledge resulting from previous courses:
• comprehension of a technical system starting from description and drawings;
• understanding of the regulation concerning occupational safety, process safety, safety of machineries;
• identification of the related hazards;
• selection of the potential accidental sequences;
• estimation of accident/failure probabilities by RAM (Reliability, Availability, Maintainability) analyses;
• estimation of damage extension in case of major accident, by simplified methods;
• identification of the preventive and mitigation measures for risk control.
The application of these concepts and tools to a real study case will be performed during practical lectures by team working; two different subject will be investigated: a portion of a process plant for petroleum students and a complex installation, composed by several machineries, for mining students.
These project works are set in order to train students in the typical approach adopted for professional risk analysis, where several specialists contribute for a common goal, by a multidisciplinary investigation.

Fundamentals on physics, chemistry, thermodynamics and fluid mechanics; fundamentals on oil&gas and mining systems and operations.

1. The Risk concept: definition, assessment, perception and tolerability.
2. Role of Risk in the International Legislation and technical Standards with a special focus on process safety, occupational safety and safety of machineries.
3. Methodologies for the risk assessment:
* Elements on the Boolean algebra and probability theory,
* Hazard identification,
* Methodologies for the reliability assessment of complex systems,
* Methodologies for the study of accidental sequences,
* Qualitative and Quantitative Risk Assessment,
* Risk Assessment and tolerability criteria,
*The role of risk assessment in the international legislation.
4. Insights on the reliability theory and RAM (Reliability, Availability, Maintainability) analyses:
* RAM characterisation of elementary components,
* Reliability Data Banks,
* Calculation of unreliability and unavailability for complex systems/machineries,
* Common Cause Failures and Criticality Indexes,
* Elements of Functional Safety.
5. Process Safety:
* Description and modelling of accidental phenomena (loss of containment, fires, explosions, gas dispersion),
* Vulnerability analysis,
* Emergency planning and management.
6. Occupational safety and safety of machineries:
* Investigation of typical hazards (HAZID methodology and statistical investigation),
* Verification of safety for machineries by RAMS studies,
* Identification of preventive and protection risk control measures.

The main part of the course consists in the presentation, by the teacher, of the context of safety and risk assessment, the relevant regulation and the professional methodologies and tools to perform this type of analyses.
One third of the course will be spent for practical application of risk analysis (Project Work). Students have to apply the contents of the lectures to perform a safety assessment of a part of a real oil&gas plant or mining system. They have to prepare, by team working, a report describing the analysis performed and a critical discussion of the results obtained.

Lecture notes prepared by the teacher; material can be downloaded by the POLITO Didactic Portal.
Other books suggested for personal deepening:
' F.P. Lees, Loss Prevention in the Process Industries, Elsevier, 1996;
' AIChE /CCPS, Guidelines for Quantitative Risk Analysis, 2000;
' Vinnem, Quantified Risk Assessment for Offshore Petroleum Installations, NTNU Trondheim Norway, 1997;
' NUREG, PRA Procedures Guide, CR2300, 1983;
' Mc Cormick, Reliability and Risk Analysis, Academic Press, 1981;
' Kletz, HAZOP & HAZAN, Inst. Chem. Eng., 1986;
' TNO, Methods for the Calculation of Physical Effects (Yellow Boook), 1997;
' TNO, Methods for the determination of possible damage, (Green Boook), 1989.

The final exam consists in:
' a written session based on questions and exercises, where each student has 1.5 hours to demonstrate its comprehension on concepts and methods presented during the theoretical lectures (max 27 points over 30); students cannot use books, slides or notes during the test.
' the evaluation, by the Teacher, of the Project Work done by the students during practical lectures (max 3 points over 30); evaluation will take into account the participation of students to the practical lectures, the contents and results of the project work and finally the quality of the final report.