19 research outputs found
Sensitivity analysis of a dynamic model for gas producing reactions under runway conditions
No full textA dynamic model to simulate the behaviour of a purely gassy system during venting is proposed. A sensitivity study of the model predictions (temperature, pressure and mass inventory) to the following parameters is performed: initial vessel fill level, vessel volume, external heat input, relief vent area and vessel aspect ratio
Carbon capture and storage: a case study of emerging risk issues in the iNTeg-Risk project
No full textThis paper describes the iNTeg-Risk Carbon Capture and Storage (CCS) case study including: identification of example hazards in the CCS process including capture, transport, injection and storage; analysis using bow-tie techniques; modification of risk matrix approaches to include potential releases in the very long term from storage sites; use of life cycle analysis approaches; possible key performance indicators (KPIs); and knowledge gaps in terms of addressing emerging risk issues. One of the key features of the CCS case study is the need to include the time dimension in the risk assessment. The assessment needs to include both short-term potential accidents (from capture, transport or injection) as well as very long term risks from storage
Modelling of the venting of an untempered system under runaway conditions
No full textRunaway reactions are statistically one of the major concerns for the chemical industry. Historically, they have been the cause for many severe incidents, as in the well-known cases of Seveso (Italy, 1976), Bhopal (India, 1984) and more recently the T2 Laboratories (USA, 2007).
The prediction of the consequences of a runaway reaction in term of temperature and pressure evolution in a reactor vessel requires the knowledge of the reaction kinetics, thermodynamics and fluid dynamics inside the vessel during venting. Such phenomena and their interaction are complex and still to be fully understood, especially for those reactions in which the pressure generation is totally or partially due to the production of permanent gases (gassy or hybrid systems). Moreover, they cannot be easily determined by laboratory scale experiments.
The work described in this paper presents a dynamic model developed to simulate the behavior of an untempered reacting mixture during venting. The model provides the temperature, pressure and inventory profiles before and during venting. A sensitivity study of the model was performed. This modeling work provides some insight regarding the interpretation of the data obtained from untempered system venting experiments. The outcomes of this work finds an application in the improvement of emergency relief systems design for hybrid and gassy systems, where significant progress is still to be made both in the experimental and modeling areas
Holistic risk management of atypical accident scenarios
No full textSeveral of the major accidents that occurred in Europe in recent years showed unexpected scenarios not considered by their site safety reports, such as the accidents at Toulouse (France) in 2001 and Buncefield (United Kingdom) in 2005. This contribution tackles this emerging risk of “atypical” accident scenarios, not captured by standard risk assessment because deviating from normal expectations, which has been firstly introduced by the EC project iNTeg-Risk. A synergy of tools developed or used within the this project is adopted as way of prevention of atypical accident scenarios. Lessons learned, recommendations and the new methodology DyPASI (Dynamic Procedure for Atypical Scenarios Identification) is completed by the REWI (Resilience based Early Warning Indicators) method. The first technique is built for the identification of atypical scenarios and is based on systematization of information from early warnings, represented by past events, near misses and in-depth studies related to the industrial process considered. The second one is a proactive methodology for the development of resilience based early warning indicators and can unveil early deviations in the casual chain of potential accident scenarios. The composition of the two represents an advanced approach to tackle this topical issue from different slants for a more complete result. However, the core of the whole project is always kept as a reference point: the Emerging Risk Management Framework (ERMF), defined to provide the basis for integration of the research and management activities in the area of emerging risks.; ; This approach has been applied with the purpose to assess risk in new and emerging technologies, such as the cases of Carbon Capture and Sequestration or Liquid Natural Gas regasification, where relative lack of experience can possibly lead to atypical accident scenarios. The results produced are described in this contribution as demonstration of effectiveness of this new holistic approach
Addressing emerging risks using carbon capture and storage as an example
No full textInternational audienceThe European iNTeg-Risk project is a large-scale integrated project aimed at improving the management of emerging risks related to new technologies in European industry. The project aims to build a new management paradigm for emerging risks as a set of principles supported by a common language, agreed tools and methods, and key performance indicators, all integrated into a single framework. It is using a number of Emerging Risk Representative Applications (ERRAs), or case studies, to inform the development of the framework; one of which concerns the carbon capture and storage (CCS) process. This paper describes the iNTeg-Risk CCS ERRA. Relevant hazards and properties of carbon dioxide are described and the emerging risks from CCS are discussed. Three new tools have been developed or trialled within the ERRA. These are: the DyPASI methodology for taking account of atypical (not usually identified) events during hazard identification; a methodology for including the time dimension in a risk assessment; and life-cycle approaches for risk management and communication. For CCS, the risk assessment needs to include both short-term potential accidents from capture, transport or injection, as well as very long-term risks from storage. Knowledge gaps which are generic to emerging risks are also identified
Development of a novel method for cross-disciplinary hazard identification
No full textHazards and risks are currently identified in generic risk silos using top-down
tools and methods which are incorporated into whole system risk management
frameworks such as enterprise risk management. The current methods of
identification and documentation are linear in approach and presentation.
However, the world is multi-dimensional requiring a method of identification
which responds to complex non-linear relationships. A method is required to
identify cross- disciplinary hazards and formulate a register method to evidence
the identified hazards. This study uses expert elicitation, web, survey and case
studies to develop a method for cross-disciplinary hazard identification by
application of the dimensions of generic, interface, causation and accumulation.
The results of the study found many of the tools and methods used for hazard
and risk identification such as hazard and operability studies took a top down
approach commencing with a known failure and establishing cause and effect.
The starting position of a known failure or event precludes identification of new
types of failure or events and perpetuates a linear approach to hazard
identification. Additionally the linear design of a risk register does not facilitate
the presentation of multidimensional hazards. The current methods do not
accommodate multiple lifecycles and components within cross discipline
relationships. The method was applied to three case studies. The first case
study had an existing risk register of 50 risks, post method application an
additional 531 hazards were identified; case study (2) a register of 49 hazards
and post method application additional hazards of 261; case study (3) an initial
register of 45 hazards and an additional 384 hazards after method application.
The impact of the method application highlights inconsistencies in the initial risk
register and provides a tool which will aid the identification understanding and
communication of hazards. Additionally it documents previously unidentified
cross-disciplinary hazards and provides a proactive register method for
identification and documentation by application of the dimensions of interface,
causation and accumulation
