Risk Of Domino Effects Research Articles

FSEM: An approach to model contribution of synergistic effect of fires for domino effects

Fires are major primary events in domino effects in chemical and process industries, and released thermal radiation is a main cause of accident propagation. In fire-induced domino effects, synergistic effect of multiple burning units will increase risk of domino effects, and the synergistic effect is time-dependent. In this study, a superimposition based new approach is proposed to model the contribution of synergistic effect of fires for domino effects, and a numerical solution of the approach is developed. In this approach, the synergistic effect of fires is modeled dynamically through time-variant target unit wall temperature and received thermal flux, and the receivable thermal dose is proposed as failure criterion and is modeled. The contributions of synergistic effect on the risk of domino effects are assessed by time to failure and escalation probability of target unit. The proposed approach is able to not only model the synergistic effect of fires, but also to understand the temporal evolution of synergistic effect when higher-level accidents occur. A case study demonstrates the effectiveness, advantages, extension of the proposed approach to model the contribution of synergistic effect for domino effects risk.

Dynamic domino effect risk assessment using Petri-nets

The domino effect accidents in process industries pose a severe threat to human life and the environment and have the potential to affect nearby facilities as well. Numerous techniques, such as the Bayesian network, have been used for modelling the domino effect. However, these techniques have inherent limitations. These include the inability to consider complex behaviour of process equipment in combined loading and the time dependency of equipment failure. In the current study, a Generalised Stochastic Petri-net model, called as DOMINO-GSPN, is developed to model domino effect accident likelihood and its propagation pattern. The proposed technique is capable of modelling time-dependent failure behaviour of the process component in combined loading. The results from the model are useful in monitoring process risk. A case study is used to demonstrate the application and effectiveness of the model. The results from the model are compared with the past study of a Bayesian network-based domino effect model. This comparative analysis highlights the unique feature of the model and its relevance as a domino effect risk assessment and management tool.

Assessing risk and resilience of critical infrastructures in the fuel and energy economy involving failure cascading effects

A practical procedure of risk and resilience assessment, with cascading failures occurring in the fuel and energy economy, is proposed. It is based on the threshold values and multi-energy methods. The probability analysis of the equipment damage is carried out using vulnerability models for various equipment classes and in the process the probit-functional analysis is applied. Resilience indices-criteria are used for assessing the resilience of plants as complex mechanical systems. The procedure proposed enables calculating threshold values of cascading failure; safe distances for equipments; probability assessment of failure propagation. It also adds to identifying the facilities triggering cascading effects; probability of the equipment damage; to assessing the amount of damage and the damage loss rate. The strategy (procedure) allows ranking the equipment as related to the risk of domino effects’ occurrence; analyzing consequences for each cascade direction and the possibility of its propagation on to the following level; evaluating the resilience state of the plant as a technical system. The damage amount and damage loss rate are evaluated comparing the load received and predetermined threshold values of cascading failure for various equipment classes. The strategy (procedure) developed will allow judging about safety of one or other type of a tank farm containing hydrocarbons; the results obtained in the process and the actual data converge. This strategy (procedure) is strongly recommended to be applied by experts in the field of industrial safety in developing industrial safety manifests, safety justification as well as in developing safety registration certificates of critical infrastructures.

PCP8 - BENELUXA INITIATIVE: WHY THE FIRST ATTEMPT OF JOINT ASSESSMENT FAILED?

An increasing trend toward strengthening multinational collaborations on drug procurement has been seen recently among European countries with the aim to contain growing economic burden of new expensive medicines and to increase access to medicines in these countries. BeNeLuxA initiative is one of the first prominent example of European cross-border collaborations, and the sole initiative which, to date, published results including that of its first joint HTA for informing pricing and reimbursement pilot. The drug combination lumacaftor/ivacaftor indicated for the treatment of cystic fibrosis was jointly assessed by two out of four BeNeLuxA collaborating members, the Netherlands and Belgium. Joint negotiation of lumacaftor/ivacaftor ended up with the absence of consensus on the product price, while the drug was considered not to be cost-effective, and the price assessed to be overestimated by about 80%. One strategic error during this first joint assessment of lumacaftor/ivacaftor was the selection of an orphan product as pilot. Orphan drugs are usually not cost-effective, while the joint assessment was driven by cost- effectiveness analysis. It was unlikely that the manufacturer will be willing to accept an 80% price reduction with a stakeholder presenting 28.5 million inhabitants, the risk of domino effect on others European countries being extremely high versus the potential revenue. BeNeLuxA brought few small-market countries together into negotiations thereby increasing their bargain power. However, even upon recent accession of Ireland, all member countries together are less than market of one large European country. The limited power of volume is inherent to BeNeLuxA initiative, yet, is counter-balanced by the intense collaboration that beyond joint HTA and pricing negotiations encompasses horizon scanning and information sharing, the framework in place and the shared vision. If more countries join it may be the first one to land a successful procurement.

Low overhead communication‐induced checkpointing protocols ensuring rollback‐dependency trackability property

SummaryCommunication‐induced checkpointing (CIC) protocols aim at finding consistent global checkpoint from which a system can safely restart without the risk of domino effect. CIC class gives processes the maximum autonomy for taking their local checkpoints while directs them to take forced checkpoints when harm patterns are detected. Such patterns can constitute of non‐causally doubled Z‐paths that violate the causal relation and can cause checkpoints uselessness, which results in hidden dependencies between checkpoints. Ensuring the absence of hidden dependencies hence means the ensure of the Rollback‐Dependency Trackability (RDT) property.Reducing the control information overhead is the main aim of our proposals. Our first proposal is called CSFDAS (Constant Size Fixed Dependency After Send), and the second is called CSRDTParner (Constant Size RDTPartner). Unlike to the previous works, the new proposed protocols use direct dependency clocks instead of transitive dependency vectors while keeping only a constant size of control information on messages. Conducted simulations show that the new protocols achieve a good performance compared to the RDT protocols proposed so far in the literature.

Investigation on the approach of intercepting fragments generated by vessel explosion using barrier net

The barrier net was put between accident source and objective vessel to reduce the probability of target damage due to fragments generated by vessel explosion, and to offset the requirement of safety distance. The fragment trajectory, impact probability of fragment, ruptured probability of the impacted target, and domino effect risk were respectively calculated using Monte-Carlo simulations under the barrier net. The effects of the height of barrier net on the probability of fragments impact were mainly investigated to obtain the reasonable height of barrier net. The results showed that the domino effect risk was decreased by nearly an order of magnitude, due to the significant reduction of impact probability of fragments. The relative differences demonstrated that 70%–90% reduction in the domino effect risk was performed by the barrier net. The impact probability of fragments decreased, but the intercepting probability of the barrier net increased linearly with the height of barrier net. To save cost and leave space for emergency escape and rescue, the barrier net should be installed on an initial height level. Under the same height of barrier net, the intercepting probability will be increased much more than that under the barrier net directly installed on the ground.

Application of event sequence diagram to evaluate emergency response actions during fire-induced domino effects

Emergency response actions can significantly influence the propagation of domino effects, particularly those triggered by fires. Thus, the performance and efficiency of devised emergency response actions should be carefully evaluated and taken into account when analyzing the propagation of domino effects and their risk. In the present study, we have introduced a methodology based on Event Sequence Diagram (ESD) to evaluate and prioritize different emergency response actions based on their efficiency in preventing or delaying the propagation of domino effect. Using the developed methodology, the risk of domino effects under emergency response actions can be assessed, while considering factors such as sequence, duration, correctness, and mutual interaction of the emergency response actions. We demonstrated the application of the methodology in analyzing the effect of emergency response actions on fire-induced domino effects in a fuel storage plant; the comparison of the results with previous studies illustrates the efficacy and practicality of the developed methodology.

Influence of the source size on domino effect risk caused by fragments

We developed the movement equations for fragments with the size of the bursting vessel. The ground distributions of fragments, the probability of impact between the fragments and the target, the rupture probability of the impacted target, and the domino effect risk caused by fragments were investigated for different source types and sizes using Monte-Carlo simulations. The distribution of fragments from the lower half of the source vessels onto the ground was non-zero, that is, it is probable that the fragments would hit the target vessel close to the source. The relative difference of impact probability is larger than 10% when the target vessel is within eight times the source diameter for the three types of sources considered. The proportion of impacts of fragments from the lower part of the source to total impact decreased with distance, while that for fragments from the upper part increased. The proportion of upper and lower parts is equal for distance approximately five times the source diameter. The source size needs to be considered along with the distance from the source to the target when less than approximately 14 times the source diameter. Its effect on impact probability and domino effect risk was significant. The rupture probability of the target depended very little on the source size.

Reduction Effect of The Clapboard of Polyphenylene Oxide on Domino Effect Risk Caused by Fragments

Reduction Effect of The Clapboard of Polyphenylene Oxide on Domino Effect Risk Caused by Fragments

Application of a multi-plant QRA: A case study investigating the risk impact of the construction of a new plant on an existing chemical plant's risk levels

The construction of chemical clusters whereby a variety of chemical plants are located next to each other provides great economic benefits. However, in such clusters, due to the mere scale on which hazardous materials are processed, stored and handled, the potential of various accidents is much higher than in single companies. Furthermore, the close proximity of process installations and storage tanks in such areas gives rise to the risk of domino effects. Therefore, land use planning and layout design has always been a challenge within such clusters.In this paper, a Quantitative Risk Assessment (QRA) is carried out and used as a decision making tool to evaluate the acceptability of constructing a new chemical plant adjacent to an existing one. For this purpose, standard parameters such as individual risk and societal risk were quantified, before and after the new plant would come into operation. Given the experience of past accidents in the process industries, the likelihood of domino accidents in the two neighboring plants has also been analyzed.

The analysis of domino accidents triggered by vapor cloud explosions

Domino effect is a well-known cause of severe accidents in the chemical and process industry. Several studies pointed out that the more critical step in the quantitative assessment of domino hazards is the availability of reliable models to estimate the possibility and probability of the escalation of primary accidents. This work focused on the revision of available models for the quantitative estimation of damage probability to plant equipment caused by pressure waves generated by a primary accident. Available data on damages to process equipment caused by pressure waves were analyzed. Several specific probit functions for different elements of process equipment were obtained from the analysis of failure data. The analysis of blast wave propagation in different types of explosions allowed the estimation of the expected damage probability as a function of distance from the explosion center and of explosion strength. The results obtained were used to assess safety distance criteria and to evaluate the contribution to individual risk of domino effect due to pressure waves.

The quantitative assessment of domino effect caused by overpressure: Part II. Case studies

A quantitative assessment of the contribution to industrial risk of domino effect due to overpressure was undertaken by using the damage probability models developed in part I. Two case studies derived from the actual lay-out of an oil refinery were analyzed. Individual and societal risk indexes were estimated both in the absence and in the presence of the domino effects caused by overpressure. An increase of individual risk up to an order of magnitude was found when considering domino effects.