1,752 research outputs found
A Bayesian-network approach for assessing the probability of success of physical security attacks to offshore Oil&Gas facilities
No full textOffshore Oil&Gas facilities are attractive targets of intentional malicious attacks (security attacks) that may trigger cascading events (e.g., the release and dispersion of hazardous material and/or energy, fires, explosions) with consequences on people, environment, and assets. The severity of these consequences is potentially similar to those arising from major accident scenarios originated by conventional safety-related causes. Current practice in managing the risk of security attacks mostly relies on qualitative or semi-quantitative procedures developed over the years in the offshore Oil&Gas industry. In the present study, a systematic quantitative procedure is developed, based on a Bayesian Network (BN) approach, for calculating the probability of success of physical security attacks, taking into account both preventive and mitigative security intervention strategies. The procedure addresses the specific framework of the offshore Oil&Gas industry. A case study concerning an offshore fixed Oil&Gas platform allowed us to demonstrate the quality of the results that can be achieved and their potential towards the improvement of the security of the installations considered
Numerical Investigation of the Rotor-Rotor Aerodynamic Interaction for eVTOL Aircraft Configurations
No full textThe rotor-rotor aerodynamic interaction is one of the key phenomena that characterise the flow and the performance of most of the new urban air mobility vehicles (eVTOLs) developed in the recent years. The present article describes a numerical activity that aimed to the systematic study of the rotor-rotor aerodynamic interaction with application to the flight conditions typical of eVTOL aircraft. The activity considers the use of a novel mid-fidelity aerodynamic solver based on vortex particle method. In particular, numerical simulations were performed when considering two propellers both in side-by-side and tandem configuration with different separation distances. The results of numerical simulations showed a slight reduction of the propellers performance in side-by-side configuration, while a remarkable loss of thrust in the order of 40% and a reduction of about 20% of the propulsive efficiency were found in tandem configuration, particularly when the propeller disks are completely overlapped. Moreover, the flow field analysis enabled providing a detailed insight regarding the flow physics involved in such aerodynamic interactions
Identification of reference scenarios for security attacks to the process industry
No full textThe possibility of inducing severe security-related events with damage to people, property, and the environment by deliberate malicious attacks to chemical and process plants handling large quantities of hazardous materials received an increasing attention in recent years. The identification of the credible security scenarios is required by Security Vulnerability/Risk Assessment (SVA/SRA) methodologies. However, the current availability of supporting tools is limited. This may hinder a proper management of the risks, especially in the European context where security threats are only marginally recognized under the Seveso legislation. The present study aims at supporting a harmonized identification of the scenarios triggered by deliberate malicious physical attacks to chemical and process plants. An approach based on Bow-Tie formalism is proposed to identify reference security scenarios. The Bow-Tie diagram is used to link the attack modes (Attack Tree) to the relevant release scenarios (Security Events) and to the physical damage scenarios (Event Tree). Reference Bow-Tie diagrams were defined considering substances commonly present in process plants (e.g. flammable substances and oxidizing solids). The validation of the reference scenarios (both attack scenarios and physical damage scenarios) was provided by the analysis of more than 20 security-related incidents that occurred in chemical and process facilities worldwide in the last 50 years. Application to a case-study proved the effectiveness of the results achieved in supporting SVA/SRA studies and in promoting integration among safety and security management.(c) 2022 Institution of Chemical Engineers. Published by Elsevier Ltd. All rights reserved
Identification of cyber-risks for the control and safety instrumented systems: a synergic framework for the process industry
No full textMalicious interferences to Industrial Automation and Control Systems (IACS) such as the Basic Process Control System (BPCS) and the Safety Instrumented System (SIS) of chemical and process facilities may initiate events with severe consequences such as major accident scenarios (e.g., loss of containment of hazardous substances) and production outages. Existing security vulnerability and risk assessment (SVA/SRA) methodologies, as well as the cyber-risk assessment approach proposed by ISA/IEC 62443 series of standards, do not provide any practical method or guideline supporting cyber-risk identification. Moreover, an evident lack of procedures addressing the concrete connection between malicious manipulations of the BPCS and SIS and the impacts on the physical process system that can be initiated, is present in the scientific literature. Given the outlined gap, in the present study, a synergic framework of tools is described and applied to a case study (offshore Oil&Gas platform for gas compression), supporting the systematic identification of the risks that can originate as a result of a malicious interference to the BPCS and SIS. The framework consists of a past incident analysis (PIA) and of two rigorous methodologies, PHAROS, focused on major accident hazards, and POROS, addressing also operability issues. The concept of cyber-attack credibility is here introduced to identify the most credible sets of manipulations based on the score of the plant knowledge level required by the attacker and that of the cyber complexity of the attack pattern, allowing to provide valuable information on how to effectively allocate resources for a more secure network architecture
Critical Cybersecurity Scenarios in Drinking Water Treatment Plants
No full textThe increasing interconnectivity with external networks and the higher reliance on digital systems make chemical and process industries, including waste and drinking water treatment plants, more vulnerable to cyberattacks. Historical evidence shows that these attacks have the potential to cause events with severe consequences on property, people, and the surrounding environment, posing a serious threat. While the risks deriving from the malicious manipulation of the Basic Process Control System (BPCS) and the Safety Instrumented System (SIS) in chemical and Oil&Gas facilities have been systematically analysed in the available literature, including previous works of the Authors, the analysis of the consequences of cyber-attacks to drinking water treatment plants has not been conducted to date. To fill this gap, in the present study the methodology POROS 2.0 (Process Operability Analysis of Remote manipulations through the cOntrol System) developed by the Authors was applied to a drinking water treatment plant, providing valuable insights on possible critical scenarios originated by cyber-attacks in these facilities
Risk Identification for Cyber-Attacks to the Control System in Chemical and Process Plants
No full textCyber-attacks are becoming a growing concern for process facilities that highly rely on Operational Technology (OT) systems for the potential severity of the consequences on humans, assets, and the environment that can be generated. The study is based on the development of synergic tools aimed at filling the gap in the availability of specific approaches to support cyber risk identification phase required by Security Vulnerability/Risk Assessment methodologies and the cybersecurity risk assessment proposed by ISA/IEC 62443 series of standards on cybersecurity of Industrial Automation and Control Systems (IACS)
A Bow-Tie Approach for the Identification of Scenarios Induced by Physical Intentional Attacks to Chemical and Process Plants
No full textThe possibility of inducing major accident scenarios by physical intentional attacks (e.g. terrorist attacks) to chemical and process plants processing and storing hazardous substances, has been increasingly recognized in the last decades. The identification of the credible security scenarios (chain from attack scenarios to major accident scenarios) is required by Security Vulnerability/Risk Assessment (SVA/SRA) methodologies, but an evident lack of supporting tools is present in the literature. The present study proposes a Bow-Tie approach for the identification of reference security scenarios to support hazard identification phase in SVA/SRA. The potential use of the results is demonstrated on a test case (industrial atmospheric tank storing a flammable liquid)
Modelling standoff distances to prevent escalation in shooting attacks to tanks storing hazardous materials
No full textIndustrial equipment storing hazardous substances can be the target of intentional malicious attacks causing escalation scenarios involving the release of flammable and/or toxic material with severe consequences on people, assets, and the environment. In the present study, a novel modelling approach was developed to assess the baseline values of standoff distances for atmospheric and pressurized storage equipment considering a set of standardized handgun and rifle projectiles not specific for military uses. The calculation of standoff distances is based on specific models for projectile perforation and flight. The range of standoff distances varies depending on the type of firearm used. Standoff distances resulted in the range of less than 10 meters in case of handgun projectiles and up to 1130 meters in case of hard-core rifle projectiles. Important differences in standoff distances were found for atmospheric and pressurized tanks. The effect of the initial offset angle of the shooter on the standoff distance was assessed by a Monte Carlo analysis based on credible offset angles for handgun and rifle projectiles. A case study demonstrates the importance of the results to improve chemical site security with respect to attack detection, emergency response, and mitigation actions aimed at preventing escalation scenarios
Mid-fidelity approach to aerodynamic simulations of unconventional VTOL aircraft configurations
No full textA new flexible medium-fidelity open source computational tool was developed with the purpose of obtaining fast and reliable aerodynamic simulations of unconventional Vertical Take-Off and Landing (VTOL) aircraft configurations, such as the emerging category of eVTOLs. This tool, called DUST, ensures quick simulations and provides reasonably accurate results when the need for numerous evaluations rules out an extensive use of CFD due to its high computational cost, while maintaining robustness in the complex interactional aerodynamic phenomena typical of the novel eVTOL configurations. The paper first presents the analytical formulation of the tool, based on different potential boundary elements and vortex particles wake integrated in a common formulation. Then, the results obtained with the novel code are compared with experimental data and CFD results of a half-span tiltwing tiltrotor model and an eVTOL multi-rotor tiltwing aircraft, both in hover and forward flight mode. The comparisons show that DUST produces results that are as accurate as the results obtained with CFD, except for massively separated conditions, at a computational cost orders of magnitude lower. The results highlight the effectiveness of this approach for the preliminary design of a vehicle and for the preliminary study of the flow physics related to the aerodynamic interactions between rotor wakes and solid bodies as wings
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