1,720,974 research outputs found
The Influence of Risk Prevention Measures on the Frequency of Failure of Piping
No full textThe main causes of accident in chemical industry are due to deficiencies in the corporate structure, this means the effects of management and organizational variables must be incorporated into the assessment of the frequency. This work focuses attention on the frequency assessment of failure in piping, in particular loss of containment. Some methodologies for the quantification of the effects of measures of risk prevention on the frequencies of rupture of piping are available in literature. The method presented in this paper is a simple approach based on the definition of the links between the causes of failure and the measures adopted by the company to prevent them. After an overview on the causes of failure in piping, the paper describes the approach, the application to a case-study and the study of the sensitivity of the method
Frequencies assessment of Loss of Containment including the effects of measures of risk prevention
No full textThis paper presents a method for the quantification of the effects of measures of risk
prevention of the frequency for rupture of pipework. Some methodologies, given in the
literature for this purpose, assume that each plant under analysis is characterized by the same
combinations of causes of failure and prevention mechanisms but this assumption is not
always true. The approach suggested here is based on the methodology proposed in 1999 by
Papazoglou for the quantification of the effects of organizational and managerial factors.
Taking advantage of this methodology the objective of the assessment of the influence of
measures of risk prevention in pipework has been achieved through the definition of the
links between the causes of failure and the measures adopted by the company in order to
prevent and/or to mitigate them
Quantitative assessment of the risk associated to the transport of hazardous substances by pipeline
No full textThe transport of hazardous substances by pipeline has a high social acceptability and is widely diffused. However, several accidents resulting in fatalities and in severe environmental contamination are reported in the literature. Conventional quantitative risk assessment (QRA) techniques are widely applied to pipeline safety analysis, but these methods seldom take into account the environmental consequences of accidental events.
In the present study a specific methodology and a software tool, TRAT-GIS 4.1, were applied to the analysis of the risk to people and environment due to pipeline transport of hazardous substances. Well known individual and societal risk plots were obtained for loss of containment of flammable and toxic substances. On the other hand, the methodology provides as well the extension of potential contaminated areas and overall cost figures expressing the severity of the expected environmental damage associated to the spill of substances dangerous for the environment. The methodology and the software were applied to several case-studies, and the results were compared to those provided by conventional methods. The analysis of the case-studies evidenced the potentiality of the method as a possible tool for decision support, in particular in the case of pipeline hazmat transport though areas where an important environmental heritage is present
Influence of Measures of Risk Prevention and Mitigation on the Frequencies of Rupture of Pipework
No full textThe paper presents a method for the quantification of the effects of measures of risk prevention or mitigation on the frequencies of rupture of pipework.
Some methodologies are given in the literature to this purpose; they however assume that each plant under analysis is characterized by the same combinations of failure causes and prevention mechanisms and this assumption is not always true.
The approach suggested in this paper is based on the methodology proposed by I.A.Papazoglou in 1999 for the quantification of the effects of the organizational and managerial factors. Taking advantage of such methodology the objective has been achieved through the definition of the ties between the failure causes that are the origin of incidents and the measures adopted from the company in order to prevent and/or to mitigate them.
After the definition of the weights that the single failure causes can have on the incident frequencies and, on the basis of a judgement on the measures of prevention and mitigation adopted, it has been possible to proceed to the modification of the frequencies.
The methodology has been applied at the most critical random events, associated to the pipework for a petrochemical plant, which have been brought back in the Safety Report of the establishment.
The influence of the measures of risk prevention and mitigation on the failure causes has been discussed and defined according with the plant managemen
Il trasporto in condotta: valutazione del rischio per l’uomo e per l’ambiente
No full textIl trasporto in condotta rappresenta la modalità di movimentazione via terra più sicura per il trasferimento di fluidi pericolosi tra due stabilimenti. Se questo è confermato dalle basse frequenze incidentali che caratterizzano le condotte, occorre tuttavia tenere presente che i quantitativi di sostanze che possono essere rilasciate da questi impianti possono essere molto elevati, anche in presenza di sezionamenti intermedi. Questa considerazione giustifica la necessità di quantificare il rischio generato dalle condotte sia per la popolazione che per l’ambiente, con particolare riferimento agli effetti negativi provocati sul suolo ed eventualmente sulla falda acquifera dai rilasci di liquidi. In questo studio viene presentata una metodologia innovativa, implementata utilizzando uno specifico strumento software, per l’analisi quantificata del rischio per l’uomo e per l’ambiente derivante dal trasporto in condotta di sostanze pericolose. La metodologia individuata è stata applicata ad un caso di studio derivato da una situazione reale del contesto nazionale, relativa ad una condotta di collegamento tra un pozzo di estrazione di petrolio e il vicino impianto di trattamento del greggio. I risultati ottenuti hanno confermato la potenzialità e l’utilità della procedura ai fini di un’analisi del rischio complessivo generato dalle condotte, dei cui risultati si possa tenere conto in modo esteso nelle sedi in cui la valutazione di rischio di un impianto si interfaccia con le attività di pianificazione territoriale
Effect of large obstacles on high momentum jets dispersion
No full textDispersion of toxic and flammable materials from Chemical industries represents a major issue in Risk Analysis; presently, integral models are generally used to assess dispersion consequences, due to the low CPU and time requirements connected to the use of these tools.
Nevertheless, they are mainly developed and tuned for releases in open field (open spaces without relevant obstacles), and therefore they cannot properly account for the geometrical features of the dispersion domain. Computational Fluid Dynamic, on the other hand, allows a full 3D analysis, thus accounting for all the obstacles influence on the flow field, but it involves large computational requirements.
In case of gas discharge directed towards nearby large obstacles, an impinged jet is expected: if the jet hits a nearby obstacle, the gas velocity suddenly drops, minimizing the inertial dispersion phase, thus reducing the relevant air entrainment and generally increasing the damages distances. Impinged release models are included in some commercial integral models for consequences assessment even if a clear
method to decide when to use them is often missing.
The aim of this work is to provide a comparison between the two approaches (CFDs vs. integral tools) in predicting damage thresholds for both impinged and non impinged jets. A realistic case-study of industrial interest was set-up and the fine tuning of all the involved models and parameters (turbulence modeling, geometry description, mesh independence, etc.) was finalized
Valutazione delle conseguenze per rilasci accidentali di GNL: confronto tra modelli integrali e codici CFD
No full textThe use of KPIs to identify emerging risks related to advanced Liquid Natural Gas (LNG) regasification technologies
No full textAn approach for the quantification of the influence of measures of risk prevention and mitigation on frequencies of rupture in piping
No full textThe paper presents a method for the quantification of the effects of measures of risk prevention or mitigation on the frequencies of rupture of pipework. Some methodologies are given in the literature to this purpose; they however assume that each plant under analysis is characterized by the same combinations of failure causes and prevention mechanisms and this assumption is not always true. The approach suggested in this paper is based on the methodology proposed by Papazoglou (1999) for the quantification of the effects of the organizational and managerial factors. Taking advantage of such methodology the objective has been achieved through the definition of the ties between the failure causes that are the origin of incidents and the measures adopted from the company in order to prevent and/or to mitigate them
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