Showing papers on "Inherent safety published in 2005"

I2SI: A comprehensive quantitative tool for inherent safety and cost evaluation

Abstract: This paper presents details of an integrated inherent safety index (I2SI) The conceptual framework of this index was presented at the 37th Annual Loss Prevention Symposium of the AIChE (2003) and published in Process Safety Progress (volume 23(2), 136–148, 2004) In addition to the framework, the current paper discusses additional features of the index such as the cost model and system design model, which were not presented or discussed earlier I2SI is called an integrated index because the procedure considers the life cycle of the process with economic evaluation and hazard potential identification for each option I2SI is comprised of sub-indices which account for hazard potential, inherent safety potential, and add-on control requirements In addition to evaluating these respective characteristics, there are also indices that measure the economic potential of the option To demonstrate the applicability and efficacy of I2SI, an application of the index to three acrylic acid production options is also discussed in the paper

Comparison of inherent safety indices in process concept evaluation

Abstract: In conceptual design, process routes can be compared and ranked by using inherent safety indices In this paper, some inherent safety index methods presented in literature are compared and their properties and limitations discussed As a case study, an inherent safety evaluation of methyl methacrylate process routes is presented Three index based inherent safety evaluation methods are compared with expert evaluations on methyl methacrylate process routes and their subprocesses Also the index based inherent safety ranking of process routes is compared with an expert ranking

Implementing inherent safety throughout process lifecycle

Abstract: Inherent safety should be implemented as early as possible in the design life cycle, since the changes in process design are easier and cheaper the earlier they are done. The problem is, how to evaluate process alternatives in the terms of inherent safety in the early design phases, when much of the information is missing. In this paper the process life cycle phases and the possibilities of implementing and evaluating inherent safety are discussed. The applicability and accuracy of an inherent safety index method is presented by a case study.

Inherent safety evaluation in process plants— a comparison of methodologies

Abstract: A global population increase and an improved standard of living are generally expected. To meet these demands, an increased production of chemicals will be necessary while protecting human health and the environment. However, most current methods of chemical production are unsustainable. New designs must result in plants that assure process and operator safety, the sustained health of workers and the community, and the protection of the environment. Traditional safety precautions and process controls minimize risk but cannot guarantee the prevention of accidents followed by serious consequences. Therefore, the general approach to environmental and safety problems must be changed from reactive to proactive. One way is to further develop the concept of inherent safety.

Inherent safety of fuels for accelerator-driven systems

Abstract: Transient safety characteristics of accelerator-driven systems using advanced minor actinide fuels have been investigated. Results for a molybdenum-based Ceramic-Metal (CerMet) fuel, a magnesia-bas ...

Development of the Safe Tractor Assessment Rating System.

Abstract: We describe the development of the Safe Tractor Assessment and Rating System (STARS), a design-based tractor safety rating system that can be applied to new or used tractors to provide an objective assessment of their inherent safety features. A predictive rating system model, based on technical inspection, was used. Key principles underlying the system included the potential for design features to reduce the risk of an injury event occurring, and to reduce the risk of injury if such an event did occur. The rating system was based on current standards, research literature, injury and fatality data, and farmer input via focus groups. Development was an iterative process involving field, pilot, and inter-rater reliability tests. The final system was divided into six domains: rollover protection, runover protection, user protection, information and controls, pedestrian protection, and options. Within each domain, optimum design features were described for the common or serious potential injury risks, and a score was assigned for each feature. Scores were translated into a star rating, from zero stars for virtually no inherent safety features to five stars for the highest inherent safety, for each of the six domains. STARS distinguished well between older tractor models known to have few inherent safety features and newer tractor models known to have higher levels of inherent safety. STARS can provide tractor manufacturers, dealers, and users with information critical for managing tractor-associated injury risk. In Australia, it is initially being implemented within the curriculum of the technical education and training sector.

Export inherent safety NOT risk

Abstract: The author presents a personal view that production of bulk chemicals and the attendant risks are being transferred from developed to developing nations. Some evidence is presented on the transfer of production. The transferred risk is increased because of the larger scale plants that are now built in locales that are less able to cope with the increased hazards. Bhopal was an example of an inherently unsafe plant, with major hazards that could have been avoided or drastically reduced by design. It behoves the industry to adopt the inherently safer philosophy and practice in the new plants that it builds, in order to minimise the opportunity for another accident like Bhopal and the threat to our industry that such an accident would pose.

Modular multipurpose lead-bismuth fast reactors for nuclear power engineering

Abstract: Prospects of using modular lead-bismuth fast reactors (LBFRs) in nuclear power engineering are considered. Their advantages over light-water reactors from different points of view (economic, inherent safety features, spent fuel utilization, nonproliferation, etc.) are shown.

Inventory estimation for inherently safer design

Abstract: Traditional approaches to safety in process plants tend to rely on 'added-on' safety measures as a means of minimising risk. During the design process the first stage at which safety is considered in detail is the HAZOP study. Inherent safety, where safety is designed into a plant has been found to have great benefits with regards to both safety performance and operating costs. In order to implement inherent safety fully it must be considered as early as possible in the design process, before decisions have been made which are fixed and costly to change. The major barrier to this is the lack of data available in the early design stage, which prevents different options being assessed for safety. The most important variable is that of inventory, as the quantity of material present is a major factor in determining the hazard posed by that material. The use of short-cut design methods together with simplifying assumptions was investigated to determine if they could be used in an inventory estimation study. It was found that such methods could be used. Although there are uncertainties in the available data it would be possible to use the methods to estimate the inventory of a process at the route selection stage of the design study. This would enable the comparison of different process routes in order to select the route that is the safest in relation to hazardous inventories and also to pinpoint which areas of a process have the greatest effect on safety. This would aid the design engineer to focus on the most hazardous items in a process plant and minimise that hazard.

Sustainability measures for decision support: four outstanding problems for resolution

Abstract: SUMMARY Four aspects of sustainability assessment requiring greater attention and improvement are identified and discussed. These aspects are resource depletion, production scale effects, safety and reliability. LCA methodology is based on inputs as well as outputs. Materials and energy consumption are of key importance from the perspectives of resource depletion, and impacts in resource extraction and refining. Further improvement in related impact assessment methodology is needed. Environmental effects of production scale need further investigation, both from an environmental assessment viewpoint and from the need to combine environmental and economic appraisals of technologies and projects. Mass inputs and outputs are normally proportional to scale, but associated environmental effects may not be. Many industries are hazardous, and human safety should be more visible in sustainability indicators. Both inherent safety and risk assessment approaches should be considered. Reliability is a major consideration for certain products, for example electricity, but also in the context of risks and deviations from intended operation.

Comparative Analysis of Operation and Safety of Subcritical Nuclear Systems and Innovative Critical Reactors

Abstract: The main goal of this thesis work is to investigate the role of core subcriticality for safety enhancement of advanced nuclear systems, in particular, molten salt reactors, devoted to both energy production and waste incineration/transmutation. The inherent safety is considered as ultimate goal of this safety improvement. An attempt to apply a systematic approach for the analysis of the subcriticality contribution to inherent properties of hybrid system was performed. The results of this research prove that in many cases the subcriticality may improve radically the safety characteristics of nuclear reactors, and in some configurations it helps to reach the “absolute” intrinsic safety. In any case, a proper choice of subcriticality level makes all analyzed transients considerably slower and monotonic. It was shown that the weakest point of the independent-source systems with respect to the intrinsic safety is thermohydraulic unprotected transients, while in the case of the coupled-source systems the excess reactivity/current insertion events remain a matter of concern. To overcome these inherent drawbacks a new principle of realization of a coupled sub-critical system (DENNY concept) is proposed. In addition, the ways to remedy some particular safety-related problems with the help of the core sub-criticality are demonstrated. A preliminary safety analysis of the fast-spectrum molten salt reactor (REBUS concept) is also carried out in this thesis work. Finally, the potential of the alternative (to spallation) neutron sources for application in hybrid systems is examined.