Generation Risk Assessment Using Fault Trees and Turbine Cycle Simulation: Case Studies

International Nuclear Information System (INIS)

Heo, Gyun Young; Park, Jin Kyun

2009-01-01

Since 2007, Korea Atomic Energy Research Institute and Kyung Hee University have collaborated on the development of the framework to quantify human errors broken out during the test and maintenance (T and M) in secondary systems of nuclear power plants (NPPs). The project entitled 'Development of Causality Analyzer for Maintenance/Test Tasks in Nuclear Power Plants' for OPR1000 on the basis of the proposed framework is still on-going, and will come to fruition by 2010. The overall concept of GRA-HRE (Generation Risk Assessment for Human Related Events) which is the designation of the framework, and the quantification methods for evaluating risk and electric loss have introduced in other references. The originality emerged while implementing GRA-HRE could be evaluated in view of (1) recognizing the relative importance of human errors comparing with other types of mechanical and/or electrical failures, (2) providing the top-down path of the propagation of human errors by designating top events in the fault tree model as trip signals, and (3) analyzing electric loss using turbine cycle simulation. Recently, we were successfully to illustrate the applicability of GRA-HRE by simulating several abnormalities. Since the detailed methodologies were released enough to follow up, this paper is going to only exemplify the case studies

The Ohio River Valley CO2 Storage Project AEP Mountaineer Plant, West Virginia Numerical Simulation and Risk Assessment Report

Energy Technology Data Exchange (ETDEWEB)

Neeraj Gupta

2008-03-31

A series of numerical simulations of carbon dioxide (CO{sub 2}) injection were conducted as part of a program to assess the potential for geologic sequestration in deep geologic reservoirs (the Rose Run and Copper Ridge formations), at the American Electric Power (AEP) Mountaineer Power Plant outside of New Haven, West Virginia. The simulations were executed using the H{sub 2}O-CO{sub 2}-NaCl operational mode of the Subsurface Transport Over Multiple Phases (STOMP) simulator (White and Oostrom, 2006). The objective of the Rose Run formation modeling was to predict CO{sub 2} injection rates using data from the core analysis conducted on the samples. A systematic screening procedure was applied to the Ohio River Valley CO{sub 2} storage site utilizing the Features, Elements, and Processes (FEP) database for geological storage of CO{sub 2} (Savage et al., 2004). The objective of the screening was to identify potential risk categories for the long-term geological storage of CO{sub 2} at the Mountaineer Power Plant in New Haven, West Virginia. Over 130 FEPs in seven main classes were assessed for the project based on site characterization information gathered in a geological background study, testing in a deep well drilled on the site, and general site conditions. In evaluating the database, it was apparent that many of the items were not applicable to the Mountaineer site based its geologic framework and environmental setting. Nine FEPs were identified for further consideration for the site. These FEPs generally fell into categories related to variations in subsurface geology, well completion materials, and the behavior of CO{sub 2} in the subsurface. Results from the screening were used to provide guidance on injection system design, developing a monitoring program, performing reservoir simulations, and other risk assessment efforts. Initial work indicates that the significant FEPs may be accounted for by focusing the storage program on these potential issues. The

Assessment actions and communication of solid cancer development risk in scenarios RDD based on computational simulation

International Nuclear Information System (INIS)

Bulhosa, V.M.; Lima, Z.R. de; Andrade, E.R. de

2017-01-01

The complex scenario involving the disposal of radioactive material into the environment can lead to population exposure and serious issues with its unfolding events. In this context, a methodology capable of providing useful basic information, with the least amount of scenario-specific-information, for immediate and future risk assessment is of relevance. For this work a simulation of a RDD involving cesium-137 will be considered, coupling the results of the Health Physics Code System for Evaluating Accidents Involving Radioactive Materials software (HOTSPOT 3.0.3) and the epidemiological equations of the Radiation Effects Research Foundation (RERF) to support the decision making process. The results of the simulation will be used to help quantify the number of general individuals allocated to areas of higher radiological risk and of interest to medical care by providing the scientific data to develop a more appropriate approach to risk and its communication to the affected population. (author)

Assessment actions and communication of solid cancer development risk in scenarios RDD based on computational simulation

Energy Technology Data Exchange (ETDEWEB)

Bulhosa, V.M.; Lima, Z.R. de, E-mail: valquiriambrj@gmail.com, E-mail: zelmolima@yahoo.com.br [Instituto de Engenharia Nuclear (PPGIEN/IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Andrade, E.R. de, E-mail: fisica.dna@gmail.com [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil)

2017-07-01

The complex scenario involving the disposal of radioactive material into the environment can lead to population exposure and serious issues with its unfolding events. In this context, a methodology capable of providing useful basic information, with the least amount of scenario-specific-information, for immediate and future risk assessment is of relevance. For this work a simulation of a RDD involving cesium-137 will be considered, coupling the results of the Health Physics Code System for Evaluating Accidents Involving Radioactive Materials software (HOTSPOT 3.0.3) and the epidemiological equations of the Radiation Effects Research Foundation (RERF) to support the decision making process. The results of the simulation will be used to help quantify the number of general individuals allocated to areas of higher radiological risk and of interest to medical care by providing the scientific data to develop a more appropriate approach to risk and its communication to the affected population. (author)

Assessment actions and communication of solid cancer development risk in scenarios RDD based on computational simulation

Energy Technology Data Exchange (ETDEWEB)

Bulhosa, Valquiria Miranda; Lima, Zelmo R. de, E-mail: valquiriambrj@gmail.com, E-mail: zelmolima@yahoo.com.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Andrade, Edson Ramos de, E-mail: fisica.dna@gmail.com [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil)

2017-07-01

The complex scenario involving the disposal of radioactive material into the environment can lead to population exposure and serious issues with its unfolding events. In this context, a methodology capable of providing useful basic information, with the least amount of scenario-specific-information, for immediate and future risk assessment is of relevance. For this work a simulation of a Radiological Dispersal Devices involving cesium 137 will be considered, coupling the results of the Health Physics Code System for Evaluating Accidents Involving Radioactive Materials software (HotSpot 3.0.3) and the epidemiological equations of the Radiation Effects Research Foundation (RERF) to support the decision making process. The results of the simulation will be used to help quantify the number of general individuals allocated to areas of higher radiological risk and of interest to medical care by providing the scientific data to develop a more appropriate approach to risk and its communication to the affected population. (author)

Assessment actions and communication of solid cancer development risk in scenarios RDD based on computational simulation

International Nuclear Information System (INIS)

Bulhosa, Valquiria Miranda; Lima, Zelmo R. de; Andrade, Edson Ramos de

2017-01-01

The complex scenario involving the disposal of radioactive material into the environment can lead to population exposure and serious issues with its unfolding events. In this context, a methodology capable of providing useful basic information, with the least amount of scenario-specific-information, for immediate and future risk assessment is of relevance. For this work a simulation of a Radiological Dispersal Devices involving cesium 137 will be considered, coupling the results of the Health Physics Code System for Evaluating Accidents Involving Radioactive Materials software (HotSpot 3.0.3) and the epidemiological equations of the Radiation Effects Research Foundation (RERF) to support the decision making process. The results of the simulation will be used to help quantify the number of general individuals allocated to areas of higher radiological risk and of interest to medical care by providing the scientific data to develop a more appropriate approach to risk and its communication to the affected population. (author)

An Entropy Approach to Disclosure Risk Assessment: Lessons from Real Applications and Simulated Domains

Science.gov (United States)

Airoldi, Edoardo M.; Bai, Xue; Malin, Bradley A.

2011-01-01

leveraging the statistical characteristics of a visit distribution, as opposed to person-level data. It is computationally efficient and superior to existing risk assessment methods, which rely on ad hoc assessment that are often computationally expensive and unreliable. We evaluate our approach on a range of location access patterns in simulated environments. Our results demonstrate the approach is effective at estimating trail disclosure risks and the amount of self-information contained in a distributed system is one of the main driving factors. PMID:21647242

Development of radiation risk assessment simulator using system dynamics methodology

International Nuclear Information System (INIS)

Kang, Kyung Min; Jae, Moosung

2008-01-01

The potential magnitudes of radionuclide releases under severe accident loadings and offsite consequences as well as the overall risk (the product of accident frequencies and consequences) are analyzed and evaluated quantitatively in this study. The system dynamics methodology has been applied to predict the time-dependent behaviors such as feedback and dependency as well as to model uncertain behavior of complex physical system. It is used to construct the transfer mechanisms of time dependent radioactivity concentration and to evaluate them. Dynamic variations of radio activities are simulated by considering several effects such as deposition, weathering, washout, re-suspension, root uptake, translocation, leaching, senescence, intake, and excretion of soil. The time-dependent radio-ecological model applicable to Korean specific environment has been developed in order to assess the radiological consequences following the short-term deposition of radio-nuclides during severe accidents nuclear power plant. An ingestion food chain model can estimate time dependent radioactivity concentrations in foodstuffs. And it is also shown that the system dynamics approach is useful for analyzing the phenomenon of the complex system as well as the behavior of structure values with respect to time. The output of this model (Bq ingested per Bq m - 2 deposited) may be multiplied by the deposition and a dose conversion factor (Gy Bq -1 ) to yield organ-specific doses. The model may be run deterministically to yield a single estimate or stochastic distributions by 'Monte-Carlo' calculation that reflects uncertainty of parameter and model uncertainties. The results of this study may contribute to identifying the relative importance of various parameters occurred in consequence analysis, as well as to assessing risk reduction effects in accident management. (author)

Explaining probalistic risk assessment in common language

International Nuclear Information System (INIS)

Wong, J.W.

1994-01-01

Probabilistic human health risk assessment is explained in ordinary language using a hypothetical example and the ingestion equation from EPA's Risk Assessment Guidance for Superfund. A section on understanding probabilities and probability distributions used in a Monte Carlo simulation is included as well as an appendix showing the computer run and the technical assumptions behind it

Risk assessment - black art or science?

International Nuclear Information System (INIS)

Moore, G.

1988-01-01

Measures of risk can be divided into two categories, those that observe or calculate the risk of a process or project, and those that rely on the level of risk as perceived by the people during the assessment. Collection of data of accidents (where cause and effect are obvious) and experiments on animals which can then be extrapolated to humans, are two ways of risk assessment. Mathematical models and computerized simulations, using either fault tree analysis or Monte Carlo methods are explained simply. Using these methods, experts are able to perceive risk fairly realistically. However, the general public's perception of risk is often quite different, as potential risk is assessed in different ways. The concept of tolerable risk is considered, particularly with reference to nuclear reactors such as Sizewell-B. The need to inform the public of safeguards and safety procedures so they have a better understanding of the risks of nuclear power is stressed. (U.K.)

A statistical simulation model for field testing of non-target organisms in environmental risk assessment of genetically modified plants.

Science.gov (United States)

Goedhart, Paul W; van der Voet, Hilko; Baldacchino, Ferdinando; Arpaia, Salvatore

2014-04-01

Genetic modification of plants may result in unintended effects causing potentially adverse effects on the environment. A comparative safety assessment is therefore required by authorities, such as the European Food Safety Authority, in which the genetically modified plant is compared with its conventional counterpart. Part of the environmental risk assessment is a comparative field experiment in which the effect on non-target organisms is compared. Statistical analysis of such trials come in two flavors: difference testing and equivalence testing. It is important to know the statistical properties of these, for example, the power to detect environmental change of a given magnitude, before the start of an experiment. Such prospective power analysis can best be studied by means of a statistical simulation model. This paper describes a general framework for simulating data typically encountered in environmental risk assessment of genetically modified plants. The simulation model, available as Supplementary Material, can be used to generate count data having different statistical distributions possibly with excess-zeros. In addition the model employs completely randomized or randomized block experiments, can be used to simulate single or multiple trials across environments, enables genotype by environment interaction by adding random variety effects, and finally includes repeated measures in time following a constant, linear or quadratic pattern in time possibly with some form of autocorrelation. The model also allows to add a set of reference varieties to the GM plants and its comparator to assess the natural variation which can then be used to set limits of concern for equivalence testing. The different count distributions are described in some detail and some examples of how to use the simulation model to study various aspects, including a prospective power analysis, are provided.

An Integrated Simulation, Inference and Optimization Approach for Groundwater Remediation with Two-stage Health-Risk Assessment

Directory of Open Access Journals (Sweden)

Aili Yang

2018-05-01

Full Text Available In this study, an integrated simulation, inference and optimization approach with two-stage health risk assessment (i.e., ISIO-THRA is developed for supporting groundwater remediation for a petroleum-contaminated site in western Canada. Both environmental standards and health risk are considered as the constraints in the ISIO-THRA model. The health risk includes two parts: (1 the health risk during the remediation process and (2 the health risk in the natural attenuation period after remediation. In the ISIO-THRA framework, the relationship between contaminant concentrations and time is expressed through first-order decay models. The results demonstrate that: (1 stricter environmental standards and health risk would require larger pumping rates for the same remediation duration; (2 higher health risk may happen in the period of the remediation process; (3 for the same environmental standard and acceptable health-risk level, the remediation techniques that take the shortest time would be chosen. ISIO-THRA can help to systematically analyze interaction among contaminant transport, remediation duration, and environmental and health concerns, and further provide useful supportive information for decision makers.

Challenges in Risk Assessment: Quantitative Risk Assessment

OpenAIRE

Jacxsens, Liesbeth; Uyttendaele, Mieke; De Meulenaer, Bruno

2016-01-01

The process of risk analysis consists out of three components, risk assessment, risk management and risk communication. These components are internationally well spread by Codex Alimentarius Commission as being the basis for setting science based standards, criteria on food safety hazards, e.g. setting maximum limits of mycotoxins in foodstuffs. However, the technical component risk assessment is hard to elaborate and to understand. Key in a risk assessment is the translation of biological or...

A Basis Function Approach to Simulate Storm Surge Events for Coastal Flood Risk Assessment

Science.gov (United States)

Wu, Wenyan; Westra, Seth; Leonard, Michael

2017-04-01

Storm surge is a significant contributor to flooding in coastal and estuarine regions, especially when it coincides with other flood producing mechanisms, such as extreme rainfall. Therefore, storm surge has always been a research focus in coastal flood risk assessment. Often numerical models have been developed to understand storm surge events for risk assessment (Kumagai et al. 2016; Li et al. 2016; Zhang et al. 2016) (Bastidas et al. 2016; Bilskie et al. 2016; Dalledonne and Mayerle 2016; Haigh et al. 2014; Kodaira et al. 2016; Lapetina and Sheng 2015), and assess how these events may change or evolve in the future (Izuru et al. 2015; Oey and Chou 2016). However, numeric models often require a lot of input information and difficulties arise when there are not sufficient data available (Madsen et al. 2015). Alternative, statistical methods have been used to forecast storm surge based on historical data (Hashemi et al. 2016; Kim et al. 2016) or to examine the long term trend in the change of storm surge events, especially under climate change (Balaguru et al. 2016; Oh et al. 2016; Rueda et al. 2016). In these studies, often the peak of surge events is used, which result in the loss of dynamic information within a tidal cycle or surge event (i.e. a time series of storm surge values). In this study, we propose an alternative basis function (BF) based approach to examine the different attributes (e.g. peak and durations) of storm surge events using historical data. Two simple two-parameter BFs were used: the exponential function and the triangular function. High quality hourly storm surge record from 15 tide gauges around Australia were examined. It was found that there are significantly location and seasonal variability in the peak and duration of storm surge events, which provides additional insights in coastal flood risk. In addition, the simple form of these BFs allows fast simulation of storm surge events and minimises the complexity of joint probability

In silico cardiac risk assessment in patients with long QT syndrome

DEFF Research Database (Denmark)

Hoefen, Ryan; Reumann, Matthias; Goldenberg, Ilan

2012-01-01

The study was designed to assess the ability of computer-simulated electrocardiography parameters to predict clinical outcomes and to risk-stratify patients with long QT syndrome type 1 (LQT1).......The study was designed to assess the ability of computer-simulated electrocardiography parameters to predict clinical outcomes and to risk-stratify patients with long QT syndrome type 1 (LQT1)....

Managing Macroeconomic Risks by Using Statistical Simulation

Directory of Open Access Journals (Sweden)

Merkaš Zvonko

2017-06-01

Full Text Available The paper analyzes the possibilities of using statistical simulation in the macroeconomic risks measurement. At the level of the whole world, macroeconomic risks are, due to the excessive imbalance, significantly increased. Using analytical statistical methods and Monte Carlo simulation, the authors interpret the collected data sets, compare and analyze them in order to mitigate potential risks. The empirical part of the study is a qualitative case study that uses statistical methods and Monte Carlo simulation for managing macroeconomic risks, which is the central theme of this work. Application of statistical simulation is necessary because the system, for which it is necessary to specify the model, is too complex for an analytical approach. The objective of the paper is to point out the previous need for consideration of significant macroeconomic risks, particularly in terms of the number of the unemployed in the society, the movement of gross domestic product and the country’s credit rating, and the use of data previously processed by statistical methods, through statistical simulation, to analyze the existing model of managing the macroeconomic risks and suggest elements for a management model development that will allow, with the lowest possible probability and consequences, the emergence of the recent macroeconomic risks. The stochastic characteristics of the system, defined by random variables as input values defined by probability distributions, require the performance of a large number of iterations on which to record the output of the model and calculate the mathematical expectations. The paper expounds the basic procedures and techniques of discrete statistical simulation applied to systems that can be characterized by a number of events which represent a set of circumstances that have caused a change in the system’s state and the possibility of its application in the field of assessment of macroeconomic risks. The method has no

The Combined Application of Fault Trees and Turbine Cycle Simulation in Generation Risk Assessment

International Nuclear Information System (INIS)

Heo, Gyun Young; Park, Jin Kyun

2009-01-01

The paper describes a few ideas developed for the framework to quantify human errors taking place during the test and maintenance (T and M) in a secondary system of nuclear power plants, which was presented in the previous meeting. GRA-HRE (Generation Risk Assessment for Human Related Events) is composed of four essential components, the human error interpreter, the frequency estimator, the risk estimator, and the derate estimator. The proposed GRA gave emphasis on explicitly considering human errors, performing fault tree analysis including the entire balance-of-plant side, and quantifying electric loss under abnormal plant configurations. In terms of the consideration of human errors, it was hard to distinguish the effects of human errors from other failure modes in the conventional GRA because the human errors were implicitly involved in mechanical failure mode. Since the risk estimator in GRA-HRE separately deals with the basic events representing human error modes such as control failure, wrong object, omission, wrong action, etc., we can recognize their relative importance comparing with other types of mechanical failures. Other specialties in GRA-HRE came from the combined application of fault tree analysis and turbine cycle simulation. The previous study suggested that we would use the fault tree analysis with the top events designated by system's malfunction such as 'feedwater system failure' to develop the risk estimator. However, this approach could not clearly provide the path of propagation of human errors, and it was difficult to present the failure logics in some cases. In order to overcome these bottlenecks, the paper is going to propose the modified idea to setup top events and to explain how to make use of turbine cycle simulation to complete the fault trees in a cooperative manner

Offshore Platform Hydrocarbon Risk Assessment – OPHRA: Feasibility

DEFF Research Database (Denmark)

Duijm, Nijs Jan; Kozine, Igor; Markert, Frank

This report describes the feasibility demonstration of a new method to perform risk assessments for offshore platforms. This method simulates the following phenomena as concurrent sequences of events using the Arena® Discrete Event Simulation (DES) software (version 14.50.00): • Release, ignition...

Risk Assessment Uncertainties in Cybersecurity Investments

Directory of Open Access Journals (Sweden)

Andrew Fielder

2018-06-01

Full Text Available When undertaking cybersecurity risk assessments, it is important to be able to assign numeric values to metrics to compute the final expected loss that represents the risk that an organization is exposed to due to cyber threats. Even if risk assessment is motivated by real-world observations and data, there is always a high chance of assigning inaccurate values due to different uncertainties involved (e.g., evolving threat landscape, human errors and the natural difficulty of quantifying risk. Existing models empower organizations to compute optimal cybersecurity strategies given their financial constraints, i.e., available cybersecurity budget. Further, a general game-theoretic model with uncertain payoffs (probability-distribution-valued payoffs shows that such uncertainty can be incorporated in the game-theoretic model by allowing payoffs to be random. This paper extends previous work in the field to tackle uncertainties in risk assessment that affect cybersecurity investments. The findings from simulated examples indicate that although uncertainties in cybersecurity risk assessment lead, on average, to different cybersecurity strategies, they do not play a significant role in the final expected loss of the organization when utilising a game-theoretic model and methodology to derive these strategies. The model determines robust defending strategies even when knowledge regarding risk assessment values is not accurate. As a result, it is possible to show that the cybersecurity investments’ tool is capable of providing effective decision support.

Risk Management and Simulation

DEFF Research Database (Denmark)

Skovmand, David

2014-01-01

Review of: Risk Management and Simulation / Aparna Gupta. Boca Raton, FL: CRC Press, 2013, xxix + 491 pp., $99.95(H), ISBN: 978-1-4398-3594-4.......Review of: Risk Management and Simulation / Aparna Gupta. Boca Raton, FL: CRC Press, 2013, xxix + 491 pp., $99.95(H), ISBN: 978-1-4398-3594-4....

An integrated simulation method for flash-flood risk assessment: 2. Effects of changes in land-use under a historical perspective

Science.gov (United States)

Rosso, R.; Rulli, M. C.

The influence of land use changes on flood occurrence and severity in the Bisagno River (Thyrrenian Liguria, N.W. Italy is investigated using a Monte Carlo simulation approach (Rulli and Rosso, 2002). High resolution land-use maps for the area were reconstructed and scenario simulations were made for a pre-industrial (1878), an intermediate (1930) and a current (1980) year. Land-use effects were explored to assess the consequences of distributed changes in land use due to agricultural practice and urbanisation. Hydraulic conveyance effects were considered, to assess the consequences of channel modifications associated with engineering works in the lower Bisagno River network. Flood frequency analyses of the annual flood series, retrieved from the simulations, were used to examine the effect of land-use change and river conveyance on flood regime. The impact of these effects proved to be negligible in the upper Bisagno River, moderate in the downstream river and severe in the small tributaries in the lower Bisagno valley that drain densely populated urban areas. The simulation approach is shown to be capable of incorporating historical data on landscape and river patterns into quantitative methods for risk assessment.

Draught risk index tool for building energy simulations

DEFF Research Database (Denmark)

Vorre, Mette Havgaard; Jensen, Rasmus Lund; Nielsen, Peter V.

2014-01-01

Flow elements combined with a building energy simulation tool can be used to indicate areas and periods when there is a risk of draught in a room. The study tests this concept by making a tool for post-processing of data from building energy simulations. The objective is to show indications...... of draught risk during a whole year, giving building designers a tool for the design stage of a building. The tool uses simple one-at-a-time calculations of flow elements and assesses the uncertainty of the result by counting the number of overlapping flow elements. The calculation time is low, making...... it usable in the early design stage to optimise the building layout. The tool provides an overview of the general draught pattern over a period, e.g. a whole year, and of how often there is a draught risk....

Assessing exposures and risks in heterogeneously contaminated areas: A simulation approach

International Nuclear Information System (INIS)

Fingleton, D.J.; MacDonell, M.M.; Haroun, L.A.; Oezkaynak, H.; Butler, D.A.; Xue, J.

1991-01-01

The US Department of Energy (DOE) is responsible for cleanup activities at a number of facilities under its Environmental Restoration and Waste Management Program. The major goals of this program are to eliminate potential hazards to human health and the environment that are associated with contamination of these sites and, to the extent possible, make surplus real property available for other uses. The assessment of potential baseline health risks and ecological impacts associated with a contaminated site is an important component of the remedial investigation/feasibility study (RI/FS) process required at all Superfund sites. The purpose of this paper is to describe one phase of the baseline assessment, i.e., the characterization of human health risks associated with exposure to chemical contaminants in air and on interior building surfaces at a contaminated site. The model combines data on human activity patterns in a particular microenvironment within a building with contaminant concentrations in that microenvironment to calculate personal exposure profiles and risks within the building. The results of the building assessment are presented as probability distribution functions and cumulative distribution functions, which show the variability and uncertainty in the risk estimates

Assessing exposures and risks in heterogeneously contaminated areas: A simulation approach

International Nuclear Information System (INIS)

Fingleton, D.J.; MacDonell, M.M.; Haroun, L.A.; Oezkaynak, H.; Butler, D.A.; Jianping Xue

1991-01-01

The US Department of Energy (DOE) is responsible for cleanup activities at a number of facilities under its Environmental Restoration and Waste Management Program. The major goals of this program are to eliminate potential hazards to human health and the environment that are associated with contamination of these sites and, to the extent possible, make surplus real property available for other uses. The assessment of potential baseline health risks and ecological impacts associated with a contaminated site is an important component of the remedial investigation/feasibility study (RI/FS) process required at all Superfund sites. The purpose of this paper is to describe one phase of the baseline assessment, i.e., the characterization of human health risks associated with exposure to chemical contaminants in air and on interior building surfaces at a contaminated site. The model combines data on human activity patterns in a particular microenvironment within a building with contaminant concentrations in that microenvironment to calculate personal exposure profiles and risks within the building. The results of the building assessment are presented as probability distributions functions and cumulative distribution functions, which show the variability and uncertainty in the risk estimates. 23 refs., 2 figs., 1 tab

Civil migration and risk assessment methodology

International Nuclear Information System (INIS)

Onishi, Y.; Brown, S.M.; Olsen, A.R.; Parkhurst, M.A.

1981-01-01

To provide a scientific basis for risk assessment and decision making, the Chemical Migration and Risk Assessment (CMRA) Methodology was developed to simulate overland and instream toxic containment migration and fate, and to predict the probability of acute and chronic impacts on aquatic biota. The simulation results indicated that the time between the pesticide application and the subsequent runoff producing event was the most important factor determining the amount of the alachlor. The study also revealed that sediment transport has important effects on contaminant migration when sediment concentrations in receiving streams are high or contaminants are highly susceptible to adsorption by sediment. Although the capabilities of the CMRA methodology were only partially tested in this study, the results demonstrate that methodology can be used as a scientific decision-making tool for toxic chemical regulations, a research tool to evaluate the relative significance of various transport and degradation phenomena, as well as a tool to examine the effectiveness of toxic chemical control practice

Use of mechanistic simulations as a quantitative risk-ranking tool within the quality by design framework.

Science.gov (United States)

Stocker, Elena; Toschkoff, Gregor; Sacher, Stephan; Khinast, Johannes G

2014-11-20

The purpose of this study is to evaluate the use of computer simulations for generating quantitative knowledge as a basis for risk ranking and mechanistic process understanding, as required by ICH Q9 on quality risk management systems. In this specific publication, the main focus is the demonstration of a risk assessment workflow, including a computer simulation for the generation of mechanistic understanding of active tablet coating in a pan coater. Process parameter screening studies are statistically planned under consideration of impacts on a potentially critical quality attribute, i.e., coating mass uniformity. Based on computer simulation data the process failure mode and effects analysis of the risk factors is performed. This results in a quantitative criticality assessment of process parameters and the risk priority evaluation of failure modes. The factor for a quantitative reassessment of the criticality and risk priority is the coefficient of variation, which represents the coating mass uniformity. The major conclusion drawn from this work is a successful demonstration of the integration of computer simulation in the risk management workflow leading to an objective and quantitative risk assessment. Copyright © 2014. Published by Elsevier B.V.

Simulation Modeling of Resilience Assessment in Indonesian Fertiliser Industry Supply Networks

Science.gov (United States)

Utami, I. D.; Holt, R. J.; McKay, A.

2018-01-01

Supply network resilience is a significant aspect in the performance of the Indonesian fertiliser industry. Decision makers use risk assessment and port management reports to evaluate the availability of infrastructure. An opportunity was identified to incorporate both types of data into an approach for the measurement of resilience. A framework, based on a synthesis of literature and interviews with industry practitioners, covering both social and technical factors is introduced. A simulation model was then built to allow managers to explore implications for resilience and predict levels of risk in different scenarios. Result of interview with respondens from Indonesian fertiliser industry indicated that the simulation model could be valuable in the assessment. This paper provides details of the simulation model for decision makers to explore levels of risk in supply networks. For practitioners, the model could be used by government to assess the current condition of supply networks in Indonesian industries. On the other hand, for academia, the approach provides a new application of agent-based models in research on supply network resilience and presents a real example of how agent-based modeling could be used as to support the assessment approach.

Risk assessment on an Argentinean road with a dynamic traffic simulator

Science.gov (United States)

Voumard, Jérémie; Baumann, Valérie; Jaboyedoff, Michel; Derron, Marc-Henri; Penna, Ivanna

2014-05-01

The National Route 7 in Argentina is one of the most important corridors crossing the Andean Cordillera. It concentrates most of the traffic related to the Southern Common Market (MERCOSUR), it also connects Mendoza city (the fourth most populated in Argentina) with Santiago de Chile (the Chile capital city), and is used by tourists to access to the Aconcagua National park, Puente del Inca natural monument, skiing resorts, and to local displacements for the villages along the Mendoza valley. The road crosses the Andes through the Mendoza river valley at an elevation between 2'000 and 3'000 m. The traffic (2500 vehicles/day) is composed of motorcycles, cars and pickup trucks, trucks without trailer, buses, and semi-trailer trucks. Debris flows developed along tributaries of the Mendoza River, and due to remobilization of talus materials, impact frequently the road, causing traffic disruptions, bridges damages, etc. Rock falls detached from highly fractured outcrops also impact frequently the road, causing sometimes casualties. The aim of this study is to evaluate risk along sections of the National Road 7 develop along the Mendoza river, using a dynamic traffic simulator based on MATLAB© routine. The dynamic traffic simulator developed for natural hazards events on roads consider different scenarios based on traffic speeds, vehicle types, interactions types, road properties and natural processes. Here we show that vehicle types and traffic variations may influence the risk estimation. The analyzed risk on several critical sections of the National Route 7 demonstrates that risk may significantly increase: 1) on sinuous sections, steep sections and because of road conditions changes (exit of tunnel, bridges, road width, etc.) because of decreasing vehicle speed, particularly with semi-trailer trucks; 2) when an event, such a debris flow, occurs and generates a vehicle tailback increasing their duration presence in the risk area.

Risk assessment of occupational exposure to benzene using numerical simulation in a complex geometry of a reforming unit of petroleum refinery.

Science.gov (United States)

Bayatian, Majid; Ashrafi, Khosro; Azari, Mansour Rezazadeh; Jafari, Mohammad Javad; Mehrabi, Yadollah

2018-04-01

There has been an increasing concern about the continuous and the sudden release of volatile organic pollutants from petroleum refineries and occupational and environmental exposures. Benzene is one of the most prevalent volatile compounds, and it has been addressed by many authors for its potential toxicity in occupational and environmental settings. Due to the complexities of sampling and analysis of benzene in routine and accidental situations, a reliable estimation of the benzene concentration in the outdoor setting of refinery using a computational fluid dynamics (CFD) could be instrumental for risk assessment of occupational exposure. In the present work, a computational fluid dynamic model was applied for exposure risk assessment with consideration of benzene being released continuously from a reforming unit of a refinery. For simulation of benzene dispersion, GAMBIT, FLUENT, and CFD post software are used as preprocessing, processing, and post-processing, respectively. Computational fluid dynamic validation was carried out by comparing the computed data with the experimental measurements. Eventually, chronic daily intake and lifetime cancer risk for routine operations through the two seasons of a year are estimated through the simulation model. Root mean square errors are 0.19 and 0.17 for wind speed and concentration, respectively. Lifetime risk assessments of workers are 0.4-3.8 and 0.0096-0.25 per 1000 workers in stable and unstable atmospheric conditions, respectively. Exposure risk is unacceptable for the head of shift work, chief engineer, and general workers in 141 days (38.77%) in a year. The results of this study show that computational fluid dynamics is a useful tool for modeling of benzene exposure in a complex geometry and can be used to estimate lifetime risks of occupation groups in a refinery setting.

The dark side of photovoltaic — 3D simulation of glare assessing risk and discomfort

International Nuclear Information System (INIS)

Rose, Thomas; Wollert, Alexander

2015-01-01

Photovoltaic (PV) systems form an important force in the implementation of renewable energies, but as we all know, the force has always its dark side. Besides efficiency considerations and discussions about architectures of power distribution networks, the increasing numbers of installations of PV systems for implementing renewable energies have secondary effects. PV systems can generate glare due to optical reflections and hence might be a serious concern. On the one hand, glare could affect safety, e.g. regarding traffic. On the other hand, glare is a constant source of discomfort in vicinities of PV systems. Hence, assessment of glare is decisive for the success of renewable energies near municipalities and traffic zones for the success of solar power. Several courts decided on the change of PV systems and even on their de-installation because of glare effects. Thus, location-based assessments are required to limit potential reflections and to avoid risks for public infrastructure or discomfort of residents. The question arises on how to calculate reflections accurately according to the environment's topography. Our approach is founded in a 3D-based simulation methodology to calculate and visualize reflections based on the geometry of the environment of PV systems. This computational model is implemented by an interactive tool for simulation and visualization. Hence, project planners receive flexible assistance for adjusting the parameters of solar panels amid the planning process and in particular before the installation of a PV system. - Highlights: • Solar panels cause glare that impacts neighborhoods and traffic infrastructures. • Glare might cause disability and discomfort. • 3D environment for the calculation of glare • Interactive tool to simulate and visualize reflections • Impact assessment of solar power plant farms

The dark side of photovoltaic — 3D simulation of glare assessing risk and discomfort

Energy Technology Data Exchange (ETDEWEB)

Rose, Thomas; Wollert, Alexander

2015-04-15

Photovoltaic (PV) systems form an important force in the implementation of renewable energies, but as we all know, the force has always its dark side. Besides efficiency considerations and discussions about architectures of power distribution networks, the increasing numbers of installations of PV systems for implementing renewable energies have secondary effects. PV systems can generate glare due to optical reflections and hence might be a serious concern. On the one hand, glare could affect safety, e.g. regarding traffic. On the other hand, glare is a constant source of discomfort in vicinities of PV systems. Hence, assessment of glare is decisive for the success of renewable energies near municipalities and traffic zones for the success of solar power. Several courts decided on the change of PV systems and even on their de-installation because of glare effects. Thus, location-based assessments are required to limit potential reflections and to avoid risks for public infrastructure or discomfort of residents. The question arises on how to calculate reflections accurately according to the environment's topography. Our approach is founded in a 3D-based simulation methodology to calculate and visualize reflections based on the geometry of the environment of PV systems. This computational model is implemented by an interactive tool for simulation and visualization. Hence, project planners receive flexible assistance for adjusting the parameters of solar panels amid the planning process and in particular before the installation of a PV system. - Highlights: • Solar panels cause glare that impacts neighborhoods and traffic infrastructures. • Glare might cause disability and discomfort. • 3D environment for the calculation of glare • Interactive tool to simulate and visualize reflections • Impact assessment of solar power plant farms.

POLICY ISSUES ASSOCIATED WITH USING SIMULATION TO ASSESS ENVIRONMENTAL IMPACTS

Energy Technology Data Exchange (ETDEWEB)

Uchitel, Kirsten; Tanana, Heather

2014-11-01

This report examines the relationship between simulation-based science and judicial assessments of simulations or models supporting evaluations of environmental harms or risks, considering both how it exists currently and how it might be shaped in the future. This report considers the legal standards relevant to judicial assessments of simulation-based science and provides examples of the judicial application of those legal standards. Next, this report discusses the factors that inform whether there is a correlation between the sophistication of a challenged simulation and judicial support for that simulation. Finally, this report examines legal analysis of the broader issues that must be addressed for simulation-based science to be better understood and utilized in the context of judicial challenge and evaluation. !

Probabilistic Approaches for Multi-Hazard Risk Assessment of Structures and Systems

Science.gov (United States)

Kwag, Shinyoung

Performance assessment of structures, systems, and components for multi-hazard scenarios has received significant attention in recent years. However, the concept of multi-hazard analysis is quite broad in nature and the focus of existing literature varies across a wide range of problems. In some cases, such studies focus on hazards that either occur simultaneously or are closely correlated with each other. For example, seismically induced flooding or seismically induced fires. In other cases, multi-hazard studies relate to hazards that are not dependent or correlated but have strong likelihood of occurrence at different times during the lifetime of a structure. The current approaches for risk assessment need enhancement to account for multi-hazard risks. It must be able to account for uncertainty propagation in a systems-level analysis, consider correlation among events or failure modes, and allow integration of newly available information from continually evolving simulation models, experimental observations, and field measurements. This dissertation presents a detailed study that proposes enhancements by incorporating Bayesian networks and Bayesian updating within a performance-based probabilistic framework. The performance-based framework allows propagation of risk as well as uncertainties in the risk estimates within a systems analysis. Unlike conventional risk assessment techniques such as a fault-tree analysis, a Bayesian network can account for statistical dependencies and correlations among events/hazards. The proposed approach is extended to develop a risk-informed framework for quantitative validation and verification of high fidelity system-level simulation tools. Validation of such simulations can be quite formidable within the context of a multi-hazard risk assessment in nuclear power plants. The efficiency of this approach lies in identification of critical events, components, and systems that contribute to the overall risk. Validation of any event or

Risk Assessment of Carbon Sequestration into A Naturally Fractured Reservoir at Kevin Dome, Montana

Energy Technology Data Exchange (ETDEWEB)

Nguyen, Minh [Univ. of Wyoming, Laramie, WY (United States); Onishi, Tsubasa [Texas A & M Univ., College Station, TX (United States); Carey, James William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Will, Bob [Schlumberger, Houston, TX (United States); Zaluski, Wade [Schlumberger, Houston, TX (United States); Bowen, David [Montana State Univ., Bozeman, MT (United States); DeVault, Brian [Vecta Oil and Gas, Dallas, TX (United States); Duguid, Andrew [Battelle Memorial Inst., Columbus, OH (United States); Spangler, Lee [Montana State Univ., Bozeman, MT (United States); Stauffer, Philip H. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-12-22

In this report, we describe risk assessment work done using the National Risk Assessment Partnership (NRAP) applied to CO₂ storage at Kevin Dome, Montana. Geologic CO₂ sequestration in saline aquifers poses certain risks including CO₂/brine leakage through wells or non-sealing faults into groundwater or to the land surface. These risks are difficult to quantify due to data availability and uncertainty. One solution is to explore the consequences of these limitations by running large numbers of numerical simulations on the primary CO2 injection reservoir, shallow reservoirs/aquifers, faults, and wells to assess leakage risks and uncertainties. However, a large number of full-physics simulations is usually too computationally expensive. The NRAP integrated assessment model (NRAP-IAM) uses reduced order models (ROMs) developed from full-physics simulations to address this issue. A powerful stochastic framework allows NRAPIAM to explore complex interactions among many uncertain variables and evaluate the likely performance of potential sequestration sites.

The Analysis of Rush Orders Risk in Supply Chain: A Simulation Approach

Science.gov (United States)

Mahfouz, Amr; Arisha, Amr

2011-01-01

Satisfying customers by delivering demands at agreed time, with competitive prices, and in satisfactory quality level are crucial requirements for supply chain survival. Incidence of risks in supply chain often causes sudden disruptions in the processes and consequently leads to customers losing their trust in a company's competence. Rush orders are considered to be one of the main types of supply chain risks due to their negative impact on the overall performance, Using integrated definition modeling approaches (i.e. IDEF0 & IDEF3) and simulation modeling technique, a comprehensive integrated model has been developed to assess rush order risks and examine two risk mitigation strategies. Detailed functions sequence and objects flow were conceptually modeled to reflect on macro and micro levels of the studied supply chain. Discrete event simulation models were then developed to assess and investigate the mitigation strategies of rush order risks, the objective of this is to minimize order cycle time and cost.

A review of probabilistic risk assessment of contaminated land

International Nuclear Information System (INIS)

Oeberg, T.; Bergbaeck, B.

2005-01-01

Background, Aims and Scope. The management and decisions concerning restoration of contaminated land often require indepth risk analyses. An environmental risk assessment is generally described as proceeding in four separate steps: hazard identification, dose-response assessment, exposure assessment, and risk characterization. The risk assessment should acknowledge and quantify the uncertainty in risk predictions. This can be achieved by applying probabilistic methods which, although they have been available for many years, are still not generally used. Risk assessment of contaminated land is an area where probabilistic methods have proved particularly useful. Many reports have appeared in the literature, mostly by North American researchers. The aim of this review is to summarize the experience gained so far, provide a number of useful examples, and suggest what may be done to promote probabilistic methods in Europe and the rest of the world. Methods. The available literature has been explored through searches in the major scientific and technical databases, WWW resources, textbooks and direct contacts with active researchers. A calculation example was created using standard simulation software. (orig.)

How Confident can we be in Flood Risk Assessments?

Science.gov (United States)

Merz, B.

2017-12-01

Flood risk management should be based on risk analyses quantifying the risk and its reduction for different risk reduction strategies. However, validating risk estimates by comparing model simulations with past observations is hardly possible, since the assessment typically encompasses extreme events and their impacts that have not been observed before. Hence, risk analyses are strongly based on assumptions and expert judgement. This situation opens the door for cognitive biases, such as `illusion of certainty', `overconfidence' or `recency bias'. Such biases operate specifically in complex situations with many factors involved, when uncertainty is high and events are probabilistic, or when close learning feedback loops are missing - aspects that all apply to risk analyses. This contribution discusses how confident we can be in flood risk assessments, and reflects about more rigorous approaches towards their validation.

Human Health Risk Assessment Simulations in a Distributed Environment for Shuttle Launch

Science.gov (United States)

Thirumalainambi, Rajkumar; Bardina, Jorge

2004-01-01

During the launch of a rocket under prevailing weather conditions, commanders at Cape Canaveral Air Force station evaluate the possibility of whether wind blown toxic emissions might reach civilian and military personnel in the near by area. In our model, we focused mainly on Hydrogen chloride (HCL), Nitrogen oxides (NOx) and Nitric acid (HNO3), which are non-carcinogenic chemicals as per United States Environmental Protection Agency (USEPA) classification. We have used the hazard quotient model to estimate the number of people at risk. It is based on the number of people with exposure above a reference exposure level that is unlikely to cause adverse health effects. The risk to the exposed population is calculated by multiplying the individual risk and the number in exposed population. The risk values are compared against the acceptable risk values and GO or NO-go situation is decided based on risk values for the Shuttle launch. The entire model is simulated over the web and different scenaria can be generated which allows management to choose an optimum decision.

Risk assessment

International Nuclear Information System (INIS)

Kinchin, G.H.

1983-01-01

After defining risk and introducing the concept of individual and societal risk, the author considers each of these, restricting considerations to risk of death. Some probabilities of death arising from various causes are quoted, and attention drawn to the care necessary in making comparisons between sets of data and to the distinction between voluntary and involuntary categories and between early and delayed deaths. The presentation of information on societal risk is discussed and examples given. The history of quantified risk assessment is outlined, particularly related to the nuclear industry, the process of assessing risk discussed: identification of hazard causes, the development of accident chains and the use of event trees, the evaluation of probability through the collection of data and their use with fault trees, and the assessment of consequences of hazards in terms of fatalities. Reference is made to the human element and common-made failures, and to studies supporting the development of reliability assessment techniques. Acceptance criteria are discussed for individual and societal risk in the nuclear field, and it is shown that proposed criteria lead to risks conservative by comparison with risks from day-to-day accidents and other potentially hazardous industries. (U.K.)

Environmental Risk Assessment of Nanomaterials

Science.gov (United States)

Bayramov, A. A.

In this paper, various aspects of modern nanotechnologies and, as a result, risks of nanomaterials impact on an environment are considered. This very brief review of the First International Conference on Material and Information Sciences in High Technologies (2007, Baku, Azerbaijan) is given. The conference presented many reports that were devoted to nanotechnology in biology and business for the developing World, formation of charged nanoparticles for creation of functional nanostructures, nanoprocessing of carbon nanotubes, magnetic and optical properties of manganese-phosphorus nanowires, ultra-nanocrystalline diamond films, and nanophotonics communications in Azerbaijan. The mathematical methods of simulation of the group, individual and social risks are considered for the purpose of nanomaterials risk reduction and remediation. Lastly, we have conducted studies at a plant of polymeric materials (and nanomaterials), located near Baku. Assessments have been conducted on the individual risk of person affection and constructed the map of equal isolines and zones of individual risk for a plant of polymeric materials (and nanomaterials).

Risk Assessment Overview

Science.gov (United States)

Prassinos, Peter G.; Lyver, John W., IV; Bui, Chinh T.

2011-01-01

Risk assessment is used in many industries to identify and manage risks. Initially developed for use on aeronautical and nuclear systems, risk assessment has been applied to transportation, chemical, computer, financial, and security systems among others. It is used to gain an understanding of the weaknesses or vulnerabilities in a system so modification can be made to increase operability, efficiency, and safety and to reduce failure and down-time. Risk assessment results are primary inputs to risk-informed decision making; where risk information including uncertainty is used along with other pertinent information to assist management in the decision-making process. Therefore, to be useful, a risk assessment must be directed at specific objectives. As the world embraces the globalization of trade and manufacturing, understanding the associated risk become important to decision making. Applying risk assessment techniques to a global system of development, manufacturing, and transportation can provide insight into how the system can fail, the likelihood of system failure and the consequences of system failure. The risk assessment can identify those elements that contribute most to risk and identify measures to prevent and mitigate failures, disruptions, and damaging outcomes. In addition, risk associated with public and environment impact can be identified. The risk insights gained can be applied to making decisions concerning suitable development and manufacturing locations, supply chains, and transportation strategies. While risk assessment has been mostly applied to mechanical and electrical systems, the concepts and techniques can be applied across other systems and activities. This paper provides a basic overview of the development of a risk assessment.

Introduction to risk assessment

International Nuclear Information System (INIS)

Raina, V.M.

2002-01-01

This paper gives an introduction to risk assessment. It discusses the basic concepts of risk assessment, nuclear risk assessment process and products, the role of risk assessment products in nuclear safety assurance, the relationship between risk assessment and other safety analysis and risk assessment and safe operating envelope

Cumulative Risk Assessment (CRA): transforming the way we assess health risks.

Science.gov (United States)

Williams, Pamela R D; Dotson, G Scott; Maier, Andrew

2012-10-16

Human health risk assessments continue to evolve and now focus on the need for cumulative risk assessment (CRA). CRA involves assessing the combined risk from coexposure to multiple chemical and nonchemical stressors for varying health effects. CRAs are broader in scope than traditional chemical risk assessments because they allow for a more comprehensive evaluation of the interaction between different stressors and their combined impact on human health. Future directions of CRA include greater emphasis on local-level community-based assessments; integrating environmental, occupational, community, and individual risk factors; and identifying and implementing common frameworks and risk metrics for incorporating multiple stressors.

Managing economic risks through simulation

International Nuclear Information System (INIS)

Griffin, B.J.; Eresman, R.K.

1994-01-01

Industrial operations are commonly managed in terms of such factors as raw material requirements, throughput, equipment reliability, and operator productivity. Simulation can be used to transform standard management performance measures into probabilistic measures which define the associated risks. These results provide valuable insight for effective management of economic risks. Case studies are presented using the Monte Carlo simulation method to demonstrate different applications of simulation techniques, various result formats, and their use for optimizing economic returns. In the first case study, design criteria for a large gas distribution system originally developed from worst-case demand estimates were modelled to provide a risk basis for decisions on alternative upgrading options. In the second, a commercial gas storage facility operation was modelled to develop economic marketing strategies balancing supply and demand requirements from multiple clients. 3 refs

Simulation for Prediction of Entry Article Demise (SPEAD): An Analysis Tool for Spacecraft Safety Analysis and Ascent/Reentry Risk Assessment

Science.gov (United States)

Ling, Lisa

2014-01-01

For the purpose of performing safety analysis and risk assessment for a potential off-nominal atmospheric reentry resulting in vehicle breakup, a synthesis of trajectory propagation coupled with thermal analysis and the evaluation of node failure is required to predict the sequence of events, the timeline, and the progressive demise of spacecraft components. To provide this capability, the Simulation for Prediction of Entry Article Demise (SPEAD) analysis tool was developed. The software and methodology have been validated against actual flights, telemetry data, and validated software, and safety/risk analyses were performed for various programs using SPEAD. This report discusses the capabilities, modeling, validation, and application of the SPEAD analysis tool.

Modeling Logistic Performance in Quantitative Microbial Risk Assessment

NARCIS (Netherlands)

Rijgersberg, H.; Tromp, S.O.; Jacxsens, L.; Uyttendaele, M.

2010-01-01

In quantitative microbial risk assessment (QMRA), food safety in the food chain is modeled and simulated. In general, prevalences, concentrations, and numbers of microorganisms in media are investigated in the different steps from farm to fork. The underlying rates and conditions (such as storage

Engineering Risk Assessment of Space Thruster Challenge Problem

Science.gov (United States)

Mathias, Donovan L.; Mattenberger, Christopher J.; Go, Susie

2014-01-01

The Engineering Risk Assessment (ERA) team at NASA Ames Research Center utilizes dynamic models with linked physics-of-failure analyses to produce quantitative risk assessments of space exploration missions. This paper applies the ERA approach to the baseline and extended versions of the PSAM Space Thruster Challenge Problem, which investigates mission risk for a deep space ion propulsion system with time-varying thruster requirements and operations schedules. The dynamic mission is modeled using a combination of discrete and continuous-time reliability elements within the commercially available GoldSim software. Loss-of-mission (LOM) probability results are generated via Monte Carlo sampling performed by the integrated model. Model convergence studies are presented to illustrate the sensitivity of integrated LOM results to the number of Monte Carlo trials. A deterministic risk model was also built for the three baseline and extended missions using the Ames Reliability Tool (ART), and results are compared to the simulation results to evaluate the relative importance of mission dynamics. The ART model did a reasonable job of matching the simulation models for the baseline case, while a hybrid approach using offline dynamic models was required for the extended missions. This study highlighted that state-of-the-art techniques can adequately adapt to a range of dynamic problems.

A simulation of probabilistic wildfire risk components for the continental United States

Science.gov (United States)

Mark A. Finney; Charles W. McHugh; Isaac C. Grenfell; Karin L. Riley; Karen C. Short

2011-01-01

This simulation research was conducted in order to develop a large-fire risk assessment system for the contiguous land area of the United States. The modeling system was applied to each of 134 Fire Planning Units (FPUs) to estimate burn probabilities and fire size distributions. To obtain stable estimates of these quantities, fire ignition and growth was simulated for...

Quantitative Microbial Risk Assessment for in Natural and Processed Cheeses

Directory of Open Access Journals (Sweden)

Heeyoung Lee

2016-08-01

Full Text Available This study evaluated the risk of Clostridium perfringens (C. perfringens foodborne illness from natural and processed cheeses. Microbial risk assessment in this study was conducted according to four steps: hazard identification, hazard characterization, exposure assessment, and risk characterization. The hazard identification of C. perfringens on cheese was identified through literature, and dose response models were utilized for hazard characterization of the pathogen. For exposure assessment, the prevalence of C. perfringens, storage temperatures, storage time, and annual amounts of cheese consumption were surveyed. Eventually, a simulation model was developed using the collected data and the simulation result was used to estimate the probability of C. perfringens foodborne illness by cheese consumption with @RISK. C. perfringens was determined to be low risk on cheese based on hazard identification, and the exponential model (r = 1.82×10−11 was deemed appropriate for hazard characterization. Annual amounts of natural and processed cheese consumption were 12.40±19.43 g and 19.46±14.39 g, respectively. Since the contamination levels of C. perfringens on natural (0.30 Log CFU/g and processed cheeses (0.45 Log CFU/g were below the detection limit, the initial contamination levels of natural and processed cheeses were estimated by beta distribution (α1 = 1, α2 = 91; α1 = 1, α2 = 309×uniform distribution (a = 0, b = 2; a = 0, b = 2.8 to be −2.35 and −2.73 Log CFU/g, respectively. Moreover, no growth of C. perfringens was observed for exposure assessment to simulated conditions of distribution and storage. These data were used for risk characterization by a simulation model, and the mean values of the probability of C. perfringens foodborne illness by cheese consumption per person per day for natural and processed cheeses were 9.57×10−14 and 3.58×10−14, respectively. These results indicate that probability of C. perfringens

Operational risk assessment.

Science.gov (United States)

McKim, Vicky L

2017-06-01

In the world of risk management, which encompasses the business continuity disciplines, many types of risk require evaluation. Financial risk is most often the primary focus, followed by product and market risks. Another critical area, which typically lacks a thorough review or may be overlooked, is operational risk. This category encompasses many risk exposure types including those around building structures and systems, environmental issues, nature, neighbours, clients, regulatory compliance, network, data security and so on. At times, insurance carriers will assess internal hazards, but seldom do these assessments include more than a cursory look at other types of operational risk. In heavily regulated environments, risk assessments are required but may not always include thorough assessments of operational exposures. Vulnerabilities may linger or go unnoticed, only to become the catalyst for a business disruption at a later time, some of which are so severe that business recovery becomes nearly impossible. Businesses may suffer loss of clients as the result of a prolonged disruption of services. Comprehensive operational risk assessments can assist in identifying such vulnerabilities, exposures and threats so that the risk can be minimised or removed. This paper lays out how an assessment of this type can be successfully conducted.

A risk assessment tool for contaminated sites in low-permeability fractured media

DEFF Research Database (Denmark)

Chambon, Julie Claire Claudia; Binning, Philip John; Jørgensen, Peter R.

2011-01-01

A risk assessment tool for contaminated sites in low-permeability fractured media is developed, based on simple transient and steady-state analytical solutions. The discrete fracture (DF) tool, which explicitly accounts for the transport along fractures, covers different source geometries...... and history (including secondary sources) and can be applied to a wide range of compounds. The tool successfully simulates published data from short duration column and field experiments. The use for risk assessment is illustrated by three typical risk assessment case studies, involving pesticides...

The useful field of view assessment predicts simulated commercial motor vehicle driving safety.

Science.gov (United States)

McManus, Benjamin; Heaton, Karen; Vance, David E; Stavrinos, Despina

2016-10-02

The Useful Field of View (UFOV) assessment, a measure of visual speed of processing, has been shown to be a predictive measure of motor vehicle collision (MVC) involvement in an older adult population, but it remains unknown whether UFOV predicts commercial motor vehicle (CMV) driving safety during secondary task engagement. The purpose of this study is to determine whether the UFOV assessment predicts simulated MVCs in long-haul CMV drivers. Fifty licensed CMV drivers (Mage = 39.80, SD = 8.38, 98% male, 56% Caucasian) were administered the 3-subtest version of the UFOV assessment, where lower scores measured in milliseconds indicated better performance. CMV drivers completed 4 simulated drives, each spanning approximately a 22.50-mile distance. Four secondary tasks were presented to participants in a counterbalanced order during the drives: (a) no secondary task, (b) cell phone conversation, (c) text messaging interaction, and (d) e-mailing interaction with an on-board dispatch device. The selective attention subtest significantly predicted simulated MVCs regardless of secondary task. Each 20 ms slower on subtest 3 was associated with a 25% increase in the risk of an MVC in the simulated drive. The e-mail interaction secondary task significantly predicted simulated MVCs with a 4.14 times greater risk of an MVC compared to the no secondary task condition. Subtest 3, a measure of visual speed of processing, significantly predicted MVCs in the email interaction task. Each 20 ms slower on subtest 3 was associated with a 25% increase in the risk of an MVC during the email interaction task. The UFOV subtest 3 may be a promising measure to identify CMV drivers who may be at risk for MVCs or in need of cognitive training aimed at improving speed of processing. Subtest 3 may also identify CMV drivers who are particularly at risk when engaged in secondary tasks while driving.

A framework to integrate software behavior into dynamic probabilistic risk assessment

International Nuclear Information System (INIS)

Zhu Dongfeng; Mosleh, Ali; Smidts, Carol

2007-01-01

Software plays an increasingly important role in modern safety-critical systems. Although, research has been done to integrate software into the classical probabilistic risk assessment (PRA) framework, current PRA practice overwhelmingly neglects the contribution of software to system risk. Dynamic probabilistic risk assessment (DPRA) is considered to be the next generation of PRA techniques. DPRA is a set of methods and techniques in which simulation models that represent the behavior of the elements of a system are exercised in order to identify risks and vulnerabilities of the system. The fact remains, however, that modeling software for use in the DPRA framework is also quite complex and very little has been done to address the question directly and comprehensively. This paper develops a methodology to integrate software contributions in the DPRA environment. The framework includes a software representation, and an approach to incorporate the software representation into the DPRA environment SimPRA. The software representation is based on multi-level objects and the paper also proposes a framework to simulate the multi-level objects in the simulation-based DPRA environment. This is a new methodology to address the state explosion problem in the DPRA environment. This study is the first systematic effort to integrate software risk contributions into DPRA environments

Uncertainty studies and risk assessment for CO2 storage in geological formations

International Nuclear Information System (INIS)

Walter, Lena Sophie

2013-01-01

Carbon capture and storage (CCS) in deep geological formations is one possible option to mitigate the greenhouse gas effect by reducing CO 2 emissions into the atmosphere. The assessment of the risks related to CO 2 storage is an important task. Events such as CO 2 leakage and brine displacement could result in hazards for human health and the environment. In this thesis, a systematic and comprehensive risk assessment concept is presented to investigate various levels of uncertainties and to assess risks using numerical simulations. Depending on the risk and the processes, which should be assessed, very complex models, large model domains, large time scales, and many simulations runs for estimating probabilities are required. To reduce the resulting high computational costs, a model reduction technique (the arbitrary polynomial chaos expansion) and a method for model coupling in space are applied. The different levels of uncertainties are: statistical uncertainty in parameter distributions, scenario uncertainty, e.g. different geological features, and recognized ignorance due to assumptions in the conceptual model set-up. Recognized ignorance and scenario uncertainty are investigated by simulating well defined model set-ups and scenarios. According to damage values, which are defined as a model output, the set-ups and scenarios can be compared and ranked. For statistical uncertainty probabilities can be determined by running Monte Carlo simulations with the reduced model. The results are presented in various ways: e.g., mean damage, probability density function, cumulative distribution function, or an overall risk value by multiplying the damage with the probability. If the model output (damage) cannot be compared to provided criteria (e.g. water quality criteria), analytical approximations are presented to translate the damage into comparable values. The overall concept is applied for the risks related to brine displacement and infiltration into drinking water

Hepatitis Risk Assessment

Science.gov (United States)

... please visit this page: About CDC.gov . Hepatitis Risk Assessment Recommend on Facebook Tweet Share Compartir Viral Hepatitis. Are you at risk? Take this 5 minute Hepatitis Risk Assessment developed ...

Operational risk in bank governance and control: How to save capital requirement through a risk transfer strategy. Evidences from a simulated case study

Directory of Open Access Journals (Sweden)

Enzo Scannella

2015-06-01

Full Text Available Operational risk management in banking has assumed such importance during the last decade. It has become increasingly important to measure, manage, and assess the impact of operational risk in the economics of banking. The purpose of this paper is to demonstrate how an effective operational risk management provides mitigating effects on capital-at-risk in banking. The paper provides evidences that an implementation of an operational risk transfer strategy reduces bank capital requirement. The paper adopts the loss distribution approach, the Monte Carlo simulation, and copula methodologies to estimate the regulatory capital and simulate an operational risk transfer strategy in banking.

GM Risk Assessment

Science.gov (United States)

Sparrow, Penny A. C.

GM risk assessments play an important role in the decision-making process surrounding the regulation, notification and permission to handle Genetically Modified Organisms (GMOs). Ultimately the role of a GM risk assessment will be to ensure the safe handling and containment of the GMO; and to assess any potential impacts on the environment and human health. A risk assessment should answer all ‘what if’ scenarios, based on scientific evidence.

Transport project evaluation: feasibility risk assessment and scenario forecasting

DEFF Research Database (Denmark)

Salling, Kim Bang; Leleur, Steen

2017-01-01

This paper presents a new approach to transport project assessment in terms of feasibility risk assessment and reference class forecasting. Conventionally, transport project assessment is based upon a Cost-Benefit Analysis (CBA) where evaluation criteria such as Benefit Cost Ratios (BCR...... on the preliminary construction cost estimates. Hereafter, a quantitative risk analysis is provided making use of Monte Carlo simulation. This approach facilitates random input parameters based upon reference class forecasting, hence, a parameter data fit has been performed in order to obtain validated probability...... Scenario Forecasting (RSF) frame. The RSF is anchored in the cost-benefit analysis; thus, it provides decision-makers with a quantitative mean of assessing the transport infrastructure project. First, the RSF method introduces uncertainties within the CBA by applying Optimism Bias uplifts...

Developing RESRAD-BASELINE for environmental baseline risk assessment

International Nuclear Information System (INIS)

Cheng, Jing-Jy.

1995-01-01

RESRAD-BASELINE is a computer code developed at Argonne developed at Argonne National Laboratory for the US Department of Energy (DOE) to perform both radiological and chemical risk assessments. The code implements the baseline risk assessment guidance of the US Environmental Protection Agency (EPA 1989). The computer code calculates (1) radiation doses and cancer risks from exposure to radioactive materials, and (2) hazard indexes and cancer risks from exposure to noncarcinogenic and carcinogenic chemicals, respectively. The user can enter measured or predicted environmental media concentrations from the graphic interface and can simulate different exposure scenarios by selecting the appropriate pathways and modifying the exposure parameters. The database used by PESRAD-BASELINE includes dose conversion factors and slope factors for radionuclides and toxicity information and properties for chemicals. The user can modify the database for use in the calculation. Sensitivity analysis can be performed while running the computer code to examine the influence of the input parameters. Use of RESRAD-BASELINE for risk analysis is easy, fast, and cost-saving. Furthermore, it ensures in consistency in methodology for both radiological and chemical risk analyses

Assessing Ecosystem Impacts from Simulant and Decontaminant Use

Science.gov (United States)

1988-05-01

reverse if necessary and identify by block number) FIELD GROUP SUB-GROUP Pollution Risk assessment Ecotoxicology 24 07 Simulants Decontaminants... ecotoxicology of those chemicals. This report presents methods from the literature and proposes a newly devised approach to rank those chemicals for damage...Oyster Reef Ecosystem Energy Flow Compartment Model 27 2. Digraph of a Nutrient-Driven Simplified Ecosystem 30 3. Digraph of a Cultivated Field Under

Cyber Risk Assessment of Transmission Lines in Smart Grids

Directory of Open Access Journals (Sweden)

Xuan Liu

2015-12-01

Full Text Available The increasing use of information technologies in power systems has increased the risk of power systems to cyber-attacks. In this paper, we assess the risk of transmission lines being overloaded due to cyber-based false data injection attacks. The cyber risk assessment is formulated as bilevel optimization problems that determine the maximum line flows under false data injection attacks. We propose efficient techniques to reduce the computation complexity of solving the bilevel problems. Specifically, primary and secondary filtering techniques are employed to identify the lines whose flows will never exceed their limits, which can significantly reduce computation burden. A special feasibility cut-based acceleration technique is introduced to further reduce the computation burden. The simulation results on the IEEE 30-bus, IEEE 118-bus, IEEE 300-bus and IEEE 2383-bus systems verify the proposed risk assessment model and the effectiveness of the proposed filtering and acceleration techniques.

Coastal Tsunami and Risk Assessment for Eastern Mediterranean Countries

Science.gov (United States)

Kentel, E.; Yavuz, C.

2017-12-01

Tsunamis are rarely experienced events that have enormous potential to cause large economic destruction on the critical infrastructures and facilities, social devastation due to mass casualty, and environmental adverse effects like erosion, accumulation and inundation. Especially for the past two decades, nations have encountered devastating tsunami events. The aim of this study is to investigate risks along the Mediterranean coastline due to probable tsunamis based on simulations using reliable historical data. In order to do this, 50 Critical Regions, CRs, (i.e. city centers, agricultural areas and summer villages) and 43 Critical Infrastructures, CIs, (i.e. airports, ports & marinas and industrial structures) are determined to perform people-centered risk assessment along Eastern Mediterranean region covering 7 countries. These countries include Turkey, Syria, Lebanon, Israel, Egypt, Cyprus, and Libya. Bathymetry of the region is given in Figure 1. In this study, NAMI-DANCE is used to carry out tsunami simulations. Source of a sample tsunami simulation and maximum wave propagation in the study area for this sample tsunami are given in Figures 2 and 3, respectively.Richter magnitude,, focal depth, time of occurrence in a day and season are considered as the independent parameters of the earthquake. Historical earthquakes are used to generate reliable probability distributions for these parameters. Monte Carlo (MC) Simulations are carried out to evaluate overall risks at the coastline. Inundation level, population density, number of passenger or employee, literacy rate, annually income level and existence of human are used in risk estimations. Within each MC simulation and for each grid in the study area, people-centered tsunami risk for each of the following elements at risk is calculated: i. City centers ii. Agricultural areas iii. Summer villages iv. Ports and marinas v. Airports vi. Industrial structures Risk levels at each grid along the shoreline are

Offshore risk assessment

CERN Document Server

Vinnem, Jan-Erik

2014-01-01

  Offshore Risk Assessment was the first book to deal with quantified risk assessment (QRA) as applied specifically to offshore installations and operations. Risk assessment techniques have been used for more than three decades in the offshore oil and gas industry, and their use is set to expand increasingly as the industry moves into new areas and faces new challenges in older regions.   This updated and expanded third edition has been informed by a major R&D program on offshore risk assessment in Norway and summarizes research from 2006 to the present day. Rooted with a thorough discussion of risk metrics and risk analysis methodology,  subsequent chapters are devoted to analytical approaches to escalation, escape, evacuation and rescue analysis of safety and emergency systems.   Separate chapters analyze the main hazards of offshore structures: fire, explosion, collision, and falling objects as well as structural and marine hazards. Risk mitigation and control are discussed, as well as an illustrat...

BNSF San Bernardino case study : positive train control risk assessment.

Science.gov (United States)

2014-09-01

The Federal Railroad Administration funded the BNSF San Bernardino Case Study to verify its Generalized Train Movement : Simulator (GTMS) risk assessment capabilities on a planned implementation of the I-ETMS PTC system. The analysis explicitly : sim...

A probabilistic seismic risk assessment procedure for nuclear power plants: (II) Application

Science.gov (United States)

Huang, Y.-N.; Whittaker, A.S.; Luco, N.

2011-01-01

This paper presents the procedures and results of intensity- and time-based seismic risk assessments of a sample nuclear power plant (NPP) to demonstrate the risk-assessment methodology proposed in its companion paper. The intensity-based assessments include three sets of sensitivity studies to identify the impact of the following factors on the seismic vulnerability of the sample NPP, namely: (1) the description of fragility curves for primary and secondary components of NPPs, (2) the number of simulations of NPP response required for risk assessment, and (3) the correlation in responses between NPP components. The time-based assessment is performed as a series of intensity-based assessments. The studies illustrate the utility of the response-based fragility curves and the inclusion of the correlation in the responses of NPP components directly in the risk computation. ?? 2011 Published by Elsevier B.V.

Using driving simulators to assess driving safety.

Science.gov (United States)

Boyle, Linda Ng; Lee, John D

2010-05-01

Changes in drivers, vehicles, and roadways pose substantial challenges to the transportation safety community. Crash records and naturalistic driving data are useful for examining the influence of past or existing technology on drivers, and the associations between risk factors and crashes. However, they are limited because causation cannot be established and technology not yet installed in production vehicles cannot be assessed. Driving simulators have become an increasingly widespread tool to understand evolving and novel technologies. The ability to manipulate independent variables in a randomized, controlled setting also provides the added benefit of identifying causal links. This paper introduces a special issue on simulator-based safety studies. The special issue comprises 25 papers that demonstrate the use of driving simulators to address pressing transportation safety problems and includes topics as diverse as neurological dysfunction, work zone design, and driver distraction. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Uncertainty studies and risk assessment for CO{sub 2} storage in geological formations

Energy Technology Data Exchange (ETDEWEB)

Walter, Lena Sophie

2013-07-01

Carbon capture and storage (CCS) in deep geological formations is one possible option to mitigate the greenhouse gas effect by reducing CO{sub 2} emissions into the atmosphere. The assessment of the risks related to CO{sub 2} storage is an important task. Events such as CO{sub 2} leakage and brine displacement could result in hazards for human health and the environment. In this thesis, a systematic and comprehensive risk assessment concept is presented to investigate various levels of uncertainties and to assess risks using numerical simulations. Depending on the risk and the processes, which should be assessed, very complex models, large model domains, large time scales, and many simulations runs for estimating probabilities are required. To reduce the resulting high computational costs, a model reduction technique (the arbitrary polynomial chaos expansion) and a method for model coupling in space are applied. The different levels of uncertainties are: statistical uncertainty in parameter distributions, scenario uncertainty, e.g. different geological features, and recognized ignorance due to assumptions in the conceptual model set-up. Recognized ignorance and scenario uncertainty are investigated by simulating well defined model set-ups and scenarios. According to damage values, which are defined as a model output, the set-ups and scenarios can be compared and ranked. For statistical uncertainty probabilities can be determined by running Monte Carlo simulations with the reduced model. The results are presented in various ways: e.g., mean damage, probability density function, cumulative distribution function, or an overall risk value by multiplying the damage with the probability. If the model output (damage) cannot be compared to provided criteria (e.g. water quality criteria), analytical approximations are presented to translate the damage into comparable values. The overall concept is applied for the risks related to brine displacement and infiltration into

Concept of risk: risk assessment and nuclear safety

International Nuclear Information System (INIS)

Thompson, P.B.

1980-01-01

The dissertation is a critical examination of risk assessment and its role in public policy. Nuclear power safety safety issues are selected as the primary source of illustrations and examples. The dissertation examines how risk assessment studies develop a concept of risk which becomes decisive for policy choices. Risk-assessment techniques are interpreted as instruments which secure an evaluation of risk which, in turn, figures prominently in technical reports on nuclear power. The philosophical critique is mounted on two levels. First, an epistemological critique surveys distinctions between the technical concept of risk and more familiar senses of risk. The critique shows that utilization of risk assessment re-structures the concept of risk. The technical concept is contrasted to the function of risk within a decision-maker's conceptual agenda and hierarchy of values. Second, an ethical critique exposes the value commitments of risk assessment recommendations. Although some of these values might be defended for policy decisions, the technical character of risk assessment obfuscates normative issues. Risk assessment is shown to be a form of factual enquiry which, nonetheless, represents a commitment to a specific selection of ethical and social values. Risk assessment should not be interpreted as a primary guide to decision unless the specific values incorporated into its concept of risk are stated explicitly and justified philosophically. Such a statement would allow value questions which have been sublimated by the factual tone of the analytic techniques to be debated on clear, social and ethical grounds

Assessing Risk-Based Performance Indicators in Safety-Critical Systems for Nuclear Power Plants

OpenAIRE

TONT Gabriela

2011-01-01

The paper proposes framework for a multidisciplinary nuclear risk and safety assessment by modeling uncertainty and combining diverse evidence provided in such a way that it could be used to represent an entire argument about a system's dependability. The identified safety issues are being treated by means of probabilistic safety assessment (PSA). The behavior simulation of power plant in thepresence of risk factors is analyzed from the vulnerability, risk and functional safety viewpoints, hi...

Dutch Risk Assessment tools

NARCIS (Netherlands)

Venema, A.

2015-01-01

The ‘Risico- Inventarisatie- en Evaluatie-instrumenten’ is the name for the Dutch risk assessment (RA) tools. A RA tool can be used to perform a risk assessment including an evaluation of the identified risks. These tools were among the first online risk assessment tools developed in Europe. The

A Corrosion Risk Assessment Model for Underground Piping

Science.gov (United States)

Datta, Koushik; Fraser, Douglas R.

2009-01-01

The Pressure Systems Manager at NASA Ames Research Center (ARC) has embarked on a project to collect data and develop risk assessment models to support risk-informed decision making regarding future inspections of underground pipes at ARC. This paper shows progress in one area of this project - a corrosion risk assessment model for the underground high-pressure air distribution piping system at ARC. It consists of a Corrosion Model of pipe-segments, a Pipe Wrap Protection Model; and a Pipe Stress Model for a pipe segment. A Monte Carlo simulation of the combined models provides a distribution of the failure probabilities. Sensitivity study results show that the model uncertainty, or lack of knowledge, is the dominant contributor to the calculated unreliability of the underground piping system. As a result, the Pressure Systems Manager may consider investing resources specifically focused on reducing these uncertainties. Future work includes completing the data collection effort for the existing ground based pressure systems and applying the risk models to risk-based inspection strategies of the underground pipes at ARC.

Combining numerical simulations with time-domain random walk for pathogen risk assessment in groundwater

Science.gov (United States)

Cvetkovic, V.; Molin, S.

2012-02-01

We present a methodology that combines numerical simulations of groundwater flow and advective transport in heterogeneous porous media with analytical retention models for computing the infection risk probability from pathogens in aquifers. The methodology is based on the analytical results presented in [1,2] for utilising the colloid filtration theory in a time-domain random walk framework. It is shown that in uniform flow, the results from the numerical simulations of advection yield comparable results as the analytical TDRW model for generating advection segments. It is shown that spatial variability of the attachment rate may be significant, however, it appears to affect risk in a different manner depending on if the flow is uniform or radially converging. In spite of the fact that numerous issues remain open regarding pathogen transport in aquifers on the field scale, the methodology presented here may be useful for screening purposes, and may also serve as a basis for future studies that would include greater complexity.

Probabilistic inhalation risk assessment due to radioactivity released from coal fired thermal power plants

International Nuclear Information System (INIS)

Tiwari, M.; Ajmal, P.Y.; Bhangare, R.C.; Sahu, S.K.; Pandit, G.G.

2014-01-01

This paper deals with assessment of radiological risk to the general public around in the neighborhood of a 1000 MWe coal-based thermal power plant. We have used Monte Carlo simulation for characterization of uncertainty in inhalation risk due to radionuclide escaping from the stack of thermal power plant. Monte Carlo simulation treats parameters as random variables bound to a given probabilistic distribution to evaluate the distribution of the resulting output. Risk assessment is the process that estimates the likelihood of occurrence of adverse effects to humans and ecological receptors as a result of exposure to hazardous chemical, radiation, and/or biological agents. Quantitative risk characterization involves evaluating exposure estimates against a benchmark of toxicity, such as a cancer slope factor. Risk is calculated by multiplying the carcinogenic slope factor (SF) of the radionuclide by the dose an individual receives. The collective effective doses to the population living in the neighborhood of coal-based thermal power plant were calculated using Gaussian plume dispersion model. Monte Carlo Analysis is the most widely used probabilistic method in risk assessment. The MCA technique treats any uncertain parameter as random variable that obeys a given probabilistic distribution. This technique is widely used for analyzing probabilistic uncertainty. In MCA computer simulation are used to combine multiple probability distributions associated with the dose and SF depicted in risk equation. Thus we get a probabilistic distribution for the risk

Wildfire risk in the wildland-urban interface: A simulation study in northwestern Wisconsin

Science.gov (United States)

Massada, Avi Bar; Radeloff, Volker C.; Stewart, Susan I.; Hawbaker, Todd J.

2009-01-01

The rapid growth of housing in and near the wildland–urban interface (WUI) increases wildfirerisk to lives and structures. To reduce fire risk, it is necessary to identify WUI housing areas that are more susceptible to wildfire. This is challenging, because wildfire patterns depend on fire behavior and spread, which in turn depend on ignition locations, weather conditions, the spatial arrangement of fuels, and topography. The goal of our study was to assess wildfirerisk to a 60,000 ha WUI area in northwesternWisconsin while accounting for all of these factors. We conducted 6000 simulations with two dynamic fire models: Fire Area Simulator (FARSITE) and Minimum Travel Time (MTT) in order to map the spatial pattern of burn probabilities. Simulations were run under normal and extreme weather conditions to assess the effect of weather on fire spread, burn probability, and risk to structures. The resulting burn probability maps were intersected with maps of structure locations and land cover types. The simulations revealed clear hotspots of wildfire activity and a large range of wildfirerisk to structures in the study area. As expected, the extreme weather conditions yielded higher burn probabilities over the entire landscape, as well as to different land cover classes and individual structures. Moreover, the spatial pattern of risk was significantly different between extreme and normal weather conditions. The results highlight the fact that extreme weather conditions not only produce higher fire risk than normal weather conditions, but also change the fine-scale locations of high risk areas in the landscape, which is of great importance for fire management in WUI areas. In addition, the choice of weather data may limit the potential for comparisons of risk maps for different areas and for extrapolating risk maps to future scenarios where weather conditions are unknown. Our approach to modeling wildfirerisk to structures can aid fire risk reduction management

Uncertainty assessment of climate change adaptation using an economic pluvial flood risk framework

DEFF Research Database (Denmark)

Zhou, Qianqian; Arnbjerg-Nielsen, Karsten

2012-01-01

It is anticipated that climate change is likely to lead to an increasing risk level of flooding in cities in northern Europe. One challenging question is how to best address the increasing flood risk and assess the costs and benefits of adapting to such changes. We established an integrated...... approach for identification and assessment of climate change adaptation options by incorporating climate change impacts, flood inundation modelling, economic tool and risk assessment and management. The framework is further extended and adapted by embedding a Monte Carlo simulation to estimate the total...

Development of Improved Caprock Integrity and Risk Assessment Techniques

Energy Technology Data Exchange (ETDEWEB)

Bruno, Michael [Geomechanics Technologies, Incorporated, Monrovia, CA (United States)

2014-09-30

GeoMechanics Technologies has completed a geomechanical caprock integrity analysis and risk assessment study funded through the US Department of Energy. The project included: a detailed review of historical caprock integrity problems experienced in the natural gas storage industry; a theoretical description and documentation of caprock integrity issues; advanced coupled transport flow modelling and geomechanical simulation of three large-scale potential geologic sequestration sites to estimate geomechanical effects from CO₂ injection; development of a quantitative risk and decision analysis tool to assess caprock integrity risks; and, ultimately the development of recommendations and guidelines for caprock characterization and CO₂ injection operating practices. Historical data from gas storage operations and CO₂ sequestration projects suggest that leakage and containment incident risks are on the order of 10-1 to 10-2, which is higher risk than some previous studies have suggested for CO₂. Geomechanical analysis, as described herein, can be applied to quantify risks and to provide operating guidelines to reduce risks. The risk assessment tool developed for this project has been applied to five areas: The Wilmington Graben offshore Southern California, Kevin Dome in Montana, the Louden Field in Illinois, the Sleipner CO₂ sequestration operation in the North Sea, and the In Salah CO₂ sequestration operation in North Africa. Of these five, the Wilmington Graben area represents the highest relative risk while the Kevin Dome area represents the lowest relative risk.

Physics-Based Fragment Acceleration Modeling for Pressurized Tank Burst Risk Assessments

Science.gov (United States)

Manning, Ted A.; Lawrence, Scott L.

2014-01-01

As part of comprehensive efforts to develop physics-based risk assessment techniques for space systems at NASA, coupled computational fluid and rigid body dynamic simulations were carried out to investigate the flow mechanisms that accelerate tank fragments in bursting pressurized vessels. Simulations of several configurations were compared to analyses based on the industry-standard Baker explosion model, and were used to formulate an improved version of the model. The standard model, which neglects an external fluid, was found to agree best with simulation results only in configurations where the internal-to-external pressure ratio is very high and fragment curvature is small. The improved model introduces terms that accommodate an external fluid and better account for variations based on circumferential fragment count. Physics-based analysis was critical in increasing the model's range of applicability. The improved tank burst model can be used to produce more accurate risk assessments of space vehicle failure modes that involve high-speed debris, such as exploding propellant tanks and bursting rocket engines.

State of risk assessment

International Nuclear Information System (INIS)

Conrad, J.

1978-03-01

In view of the growing importance assumed in recent years by scientific work on the calculation, quantification, evaluation and acceptance as well as behavior in the face of risks in general and more specifically, the risks of large industrial plants, the report attempts to provide a survey of the current situation, results and evaluation of this new branch of research, risk assessment. The emphasis of the report is on the basic discussion and criticism of the theoretical and methodological approaches used in the field of risk assessment (section 3). It is concerned above all with - methodical problems of determining and quantifying risks (3.1) - questions of the possibility of risk evaluation and comp arison (3.1, 3.2) - the premises of normative and empirical studies on decision making under risk (3.2, 3.3) - investigations into society's acceptance of risks involved in the introduction of new technologies (3.4) - attempts to combine various aspects of the field of risk assessment in a unified concept (3.5, 3.6, 3.7). Because risk assessment is embedded in the framework of decision theory and technology assessment, it can be implicitly evaluated at a more general level within this framework, as far as its possibilities and weaknesses of method and application are concerned (section 4). Sections 2 and 5 deal with the social context of origin and utilization of risk assessment. Finally, an attempt is made at a summary indicating the possible future development of risk assessment. (orig./HP) [de

Hydraulic risk assessment of bridges using UAV photogrammetry

Science.gov (United States)

Hackl, Jürgen; Adey, Bryan T.; Woźniak, Michał; Schümperlin, Oliver

2017-04-01

Road networks are essential for economic growth and development. Of the objects within a road network, bridges are of special interest, because their failure often results in relatively large interruptions to how the network is used, their replacement costs are generally large, and it usually takes a considerable amount of time to restore them once they have failed. Of the different types of bridges, bridges in mountainous regions are of special interest because their failure could cause severe societal consequences, for example, if it renders an area inaccessible. One of the main causes of the failure of bridges in mountainous regions is the occurrence of a hydraulic event, for example, flood waters above a certain level, scour below a certain depth or debris build up beyond a certain level. An assessment of risk related to a bridge in a mountainous region is challenging. The probability of occurrence of these events, and the resulting consequences, depend greatly on the characteristics (e.g. slope, soil, vegetation, precipitation, …) of the specific regions where the bridges are located. An indication of the effect of these characteristics can be seen in the sediment deposition during floods in mountain catchments. Additionally, there is often no, or no recent, topological information that can be used to develop terrain models to be used for realistic water flow simulations in mountain regions, and most hydrology and hydraulic models have been developed for lower gradient rivers and can often not be directly used to model water flow in mountain rivers. In an effort to improve the assessment of risk related to bridges in mountainous regions, using the setting for risk assessments established by Hackl et al. (2015) and Adey et al. (2016), an investigation was undertaken to determine whether unmanned aerial vehicles (UAVs) and photogrammetry could be used to generate the topological information required to run realistic water flow simulations. The process

Risk assessment and risk management of mycotoxins.

Science.gov (United States)

2012-01-01

Risk assessment is the process of quantifying the magnitude and exposure, or probability, of a harmful effect to individuals or populations from certain agents or activities. Here, we summarize the four steps of risk assessment: hazard identification, dose-response assessment, exposure assessment, and risk characterization. Risk assessments using these principles have been conducted on the major mycotoxins (aflatoxins, fumonisins, ochratoxin A, deoxynivalenol, and zearalenone) by various regulatory agencies for the purpose of setting food safety guidelines. We critically evaluate the impact of these risk assessment parameters on the estimated global burden of the associated diseases as well as the impact of regulatory measures on food supply and international trade. Apart from the well-established risk posed by aflatoxins, many uncertainties still exist about risk assessments for the other major mycotoxins, often reflecting a lack of epidemiological data. Differences exist in the risk management strategies and in the ways different governments impose regulations and technologies to reduce levels of mycotoxins in the food-chain. Regulatory measures have very little impact on remote rural and subsistence farming communities in developing countries, in contrast to developed countries, where regulations are strictly enforced to reduce and/or remove mycotoxin contamination. However, in the absence of the relevant technologies or the necessary infrastructure, we highlight simple intervention practices to reduce mycotoxin contamination in the field and/or prevent mycotoxin formation during storage.

Simulation technology used for risky assessment in deep exploration project in China

Science.gov (United States)

jiao, J.; Huang, D.; Liu, J.

2013-12-01

the real world or process, which can provide new insight to the equipment to meet requests from application and construction process and facilitates by means of direct perception and understanding of installation, debugging and experimental process of key equipment for deep exploration. Finally, the objective of project cost conservation and risk reduction can be reasonably approached. Risk assessment can be used to quantitatively evaluate the possible degree of the impact. During the research and development stage, information from the installation, debugging and simulation demonstration of the experiment process of the key instrument and equipment are used to evaluate the fatigue and safety of the device. It needs fully understanding the controllable and uncontrollable risk factors during the process, and then adjusting and improving the unsafe risk factors in the risk assessment and prediction. With combination with professional Geo software to process and interpret the environment to obtain evaluation parameters, simulation modeling is more likely close to exploration target which need more details of evaluations. From micro and macro comprehensive angles to safety and risk assessment can be achieved to satisfy the purpose of reducing the risk of equipment development, and to avoid unnecessary loss on the way of the development.

Biosafety Risk Assessment Methodology

Energy Technology Data Exchange (ETDEWEB)

Caskey, Susan Adele [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). International Biological Threat Reduction Program; Gaudioso, Jennifer M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). International Biological Threat Reduction Program; Salerno, Reynolds Mathewson [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). International Biological Threat Reduction Program; Wagner, Stefan M. [Public Health Agency of Canada, Winnipeg, MB (Canada). Canadian Science Centre for Human and Animal Health (CSCHAH); Shigematsu, Mika [National Inst. of Infectious Diseases (NIID), Tokyo (Japan); Risi, George [Infectious Disease Specialists, P.C, Missoula, MT (United States); Kozlovac, Joe [US Dept. of Agriculture (USDA)., Beltsville, MD (United States); Halkjaer-Knudsen, Vibeke [Statens Serum Inst., Copenhagen (Denmark); Prat, Esmeralda [Bayer CropScience, Monheim am Rhein (Germany)

2010-10-01

Laboratories that work with biological agents need to manage their safety risks to persons working the laboratories and the human and animal community in the surrounding areas. Biosafety guidance defines a wide variety of biosafety risk mitigation measures, which include measures which fall under the following categories: engineering controls, procedural and administrative controls, and the use of personal protective equipment; the determination of which mitigation measures should be used to address the specific laboratory risks are dependent upon a risk assessment. Ideally, a risk assessment should be conducted in a manner which is standardized and systematic which allows it to be repeatable and comparable. A risk assessment should clearly define the risk being assessed and avoid over complication.

[Physical process based risk assessment of groundwater pollution in the mining area].

Science.gov (United States)

Sun, Fa-Sheng; Cheng, Pin; Zhang, Bo

2014-04-01

Case studies of groundwater pollution risk assessment at home and abroad generally start from groundwater vulnerability, without considering the influence of characteristic pollutants on the consequences of pollution too much. Vulnerability is the natural sensitivity of the environment to pollutants. Risk assessment of groundwater pollution should reflect the movement and distribution of pollutants in groundwater. In order to improve the risk assessment theory and method of groundwater pollution, a physical process based risk assessment methodology for groundwater pollution was proposed in a mining area. According to the sensitivity of the economic and social conditions and the possible distribution of pollutants in the future, the spatial distribution of risk levels in aquifer was ranged before hand, and the pollutant source intensity corresponding to each risk level was deduced accordingly. By taking it as the criterion for the classification of groundwater pollution risk assessment, the groundwater pollution risk in the mining area was evaluated by simulating the migration of pollutants in the vadose zone and aquifer. The result show that the risk assessment method of groundwater pollution based on physical process can give the concentration distribution of pollutants and the risk level in the spatial and temporal. For single punctuate polluted area, it gives detailed risk characterization, which is better than the risk assessment method that based on aquifer intrinsic vulnerability index, and it is applicable to the risk assessment of existing polluted sites, optimizing the future sites and providing design parameters for the site construction.

Development of a Quantitative Framework for Regulatory Risk Assessments: Probabilistic Approaches

International Nuclear Information System (INIS)

Wilmot, R.D.

2003-11-01

The Swedish regulators have been active in the field of performance assessment for many years and have developed sophisticated approaches to the development of scenarios and other aspects of assessments. These assessments have generally used dose as the assessment end-point and have been based on deterministic calculations. Recently introduced Swedish regulations have introduced a risk criterion for radioactive waste disposal: the annual risk of harmful effects after closure of a disposal facility should not exceed 10 -6 for a representative individual in the group exposed to the greatest risk. A recent review of the overall structure of risk assessments in safety cases concluded that there are a number of decisions and assumptions in the development of a risk assessment methodology that could potentially affect the calculated results. Regulatory understanding of these issues, potentially supported by independent calculations, is important in preparing for review of a proponent's risk assessment. One approach to evaluating risk in performance assessments is to use the concept of probability to express uncertainties, and to propagate these probabilities through the analysis. This report describes the various approaches available for undertaking such probabilistic analyses, both as a means of accounting for uncertainty in the determination of risk and more generally as a means of sensitivity and uncertainty analysis. The report discusses the overall nature of probabilistic analyses and how they are applied to both the calculation of risk and sensitivity analyses. Several approaches are available, including differential analysis, response surface methods and simulation. Simulation is the approach most commonly used, both in assessments for radioactive waste disposal and in other subject areas, and the report describes the key stages of this approach in detail. Decisions relating to the development of input PDFs, sampling methods (including approaches to the treatment

Simulation Technology for Skills Training and Competency Assessment in Medical Education

Science.gov (United States)

Obeso, Vivian T.; Issenberg, S. Barry

2007-01-01

Medical education during the past decade has witnessed a significant increase in the use of simulation technology for teaching and assessment. Contributing factors include: changes in health care delivery and academic environments that limit patient availability as educational opportunities; worldwide attention focused on the problem of medical errors and the need to improve patient safety; and the paradigm shift to outcomes-based education with its requirements for assessment and demonstration of competence. The use of simulators addresses many of these issues: they can be readily available at any time and can reproduce a wide variety of clinical conditions on demand. In lieu of the customary (and arguably unethical) system, whereby novices carry out the practice required to master various techniques—including invasive procedures—on real patients, simulation-based education allows trainees to hone their skills in a risk-free environment. Evaluators can also use simulators for reliable assessments of competence in multiple domains. For those readers less familiar with medical simulators, this article aims to provide a brief overview of these educational innovations and their uses; for decision makers in medical education, we hope to broaden awareness of the significant potential of these new technologies for improving physician training and assessment, with a resultant positive impact on patient safety and health care outcomes. PMID:18095044

A New Approach to Feasibility Risk Assessment within Transport Infrastructure Appraisal

DEFF Research Database (Denmark)

Salling, Kim Bang

2013-01-01

This paper introduces a new approach of applying feasibility risk assessment within transport project infrastructure appraisal. The procedure is based upon quantitative risk analysis and Monte Carlo simulation in combination with conventional cost-benefit analysis converting deterministic benefit...... are, hereby, often basing their decisions on wrongful material. The presented approach to transport infrastructure appraisal is to include uncertainties and risks in the evaluation. Correspondingly, the handling of uncertainties and risk within transport project assessment are often made up...... by sensitivity tests producing deterministically based output values. Research has proven that traditional sensitivity analysis seldomnly captures the total variability especially as concerns the costs and demands estimated in the pre-stage of the evaluation. Therefore, this paper introduces an approach...

2007 TOXICOLOGY AND RISK ASSESSMENT ...

Science.gov (United States)

EPA has announced The 2007 Toxicology and Risk Assessment Conference Cincinnati Marriott North, West Chester (Cincinnati), OHApril 23- 26, 2007 - Click to register!The Annual Toxicology and Risk Assessment Conference is a unique meeting where several Government Agencies come together to discuss toxicology and risk assessment issues that are not only of concern to the government, but also to a broader audience including academia and industry. The theme of this year's conference is Emerging Issues and Challenges in Risk Assessment and the preliminary agenda includes: Plenary Sessions and prominent speakers (tentative) include: Issues of Emerging Chemical ContaminantsUncertainty and Variability in Risk Assessment Use of Mechanistic data in IARC evaluationsParallel Sessions:Uncertainty and Variability in Dose-Response Assessment Recent Advances in Toxicity and Risk Assessment of RDX The Use of Epidemiologic Data for Risk Assessment Applications Cumulative Health Risk Assessment:

Risk Assessment

Science.gov (United States)

How the EPA conducts risk assessment to protect human health and the environment. Several assessments are included with the guidelines, models, databases, state-based RSL Tables, local contacts and framework documents used to perform these assessments.

Exploration Health Risks: Probabilistic Risk Assessment

Science.gov (United States)

Rhatigan, Jennifer; Charles, John; Hayes, Judith; Wren, Kiley

2006-01-01

Maintenance of human health on long-duration exploration missions is a primary challenge to mission designers. Indeed, human health risks are currently the largest risk contributors to the risks of evacuation or loss of the crew on long-duration International Space Station missions. We describe a quantitative assessment of the relative probabilities of occurrence of the individual risks to human safety and efficiency during space flight to augment qualitative assessments used in this field to date. Quantitative probabilistic risk assessments will allow program managers to focus resources on those human health risks most likely to occur with undesirable consequences. Truly quantitative assessments are common, even expected, in the engineering and actuarial spheres, but that capability is just emerging in some arenas of life sciences research, such as identifying and minimize the hazards to astronauts during future space exploration missions. Our expectation is that these results can be used to inform NASA mission design trade studies in the near future with the objective of preventing the higher among the human health risks. We identify and discuss statistical techniques to provide this risk quantification based on relevant sets of astronaut biomedical data from short and long duration space flights as well as relevant analog populations. We outline critical assumptions made in the calculations and discuss the rationale for these. Our efforts to date have focussed on quantifying the probabilities of medical risks that are qualitatively perceived as relatively high risks of radiation sickness, cardiac dysrhythmias, medically significant renal stone formation due to increased calcium mobilization, decompression sickness as a result of EVA (extravehicular activity), and bone fracture due to loss of bone mineral density. We present these quantitative probabilities in order-of-magnitude comparison format so that relative risk can be gauged. We address the effects of

Risk assessment of topically applied products

DEFF Research Database (Denmark)

Søborg, Tue; Basse, Line Hollesen; Halling-Sørensen, Bent

2007-01-01

The human risk of harmful substances in semisolid topical dosage forms applied topically to normal skin and broken skin, respectively, was assessed. Bisphenol A diglycidyl ether (BADGE) and three derivatives of BADGE previously quantified in aqueous cream and the UV filters 3-BC and 4-MBC were used...... as model compounds. Tolerable daily intake (TDI) values have been established for BADGE and derivatives. Endocrine disruption was chosen as endpoint for 3-BC and 4-MBC. Skin permeation of the model compounds was investigated in vitro using pig skin membranes. Tape stripping was applied to simulate broken...... parameters for estimating the risk. The immediate human risk of BADGE and derivatives in topical dosage forms was found to be low. However, local treatment of broken skin may lead to higher exposure of BADGE and derivatives compared to application to normal skin. 3-BC permeated skin at higher flux than 4-MBC...

Framework for integrating human and animal data in chemical risk assessment.

Science.gov (United States)

Lavelle, Karlene S; Robert Schnatter, A; Travis, Kim Z; Swaen, Gerard M H; Pallapies, Dirk; Money, Chris; Priem, Peter; Vrijhof, Henk

2012-03-01

Although regulatory agencies formally encourage the integration of all available data in chemical risk assessment, consistent implementation of this practice has been constrained by the lack of a clear, systematic method for doing so. In this paper, we describe a methodology for evaluating, classifying and integrating human and animal data into the risk assessment process that incorporates: (1) a balanced appraisal of human and animal data, (2) relevance to different stages of the risk assessment process, and (3) accommodation for different data quality requirements. The proposed framework offers a flexible, step-wise approach for determining which set of available data best support the chemical risk assessment that involves the rating and relative ranking of human and animal data quality. The evaluation of human data incorporates seven data quality elements, nature and specificity of the lead effect; evaluation of animal data incorporates data quality and relevance to humans. Results of simulations with selected chemicals previously evaluated in a formal risk assessment generally agreed with existing regulatory guidance. Application of the proposed framework across a wider range of chemical agents will improve transparency of the risk assessment process and validity of results, while informing continuous refinements to this evolving methodology. Copyright © 2012 Elsevier Inc. All rights reserved.

Hanford Site's Integrated Risk Assessment Program: No-intervention risk assessment

International Nuclear Information System (INIS)

Mahaffey, J.A.; Dukelow, J.S. Jr.; Stenner, R.D.

1994-08-01

The long-term goal of the Integrated Risk Assessment program (IRAP) is to estimate risks to workers, the public, organizations, and groups with reserved rights to Site access, the ecosystem, and natural resources to aid in managing environmental restoration and waste management at the Hanford Site. For each of these, information is needed about current risks, risks during cleanup, and endstate risks. The objective is three-fold: to determine if and when to remediate, and to what extent; to identify information unavailable but needed to make better cleanup decisions; to establish technology performance criteria for achieving desired cleanup levels; to understand costs and benefits of activities from a Site-wide perspective. The no-intervention risk, assessment is the initial evaluation of public health risks conducted under IRAP. The objective is to identify types of activities that the US Department of Energy (DOE) must accomplish for closure of the Hanford Site, defined as no further DOE intervention. There are two primary conclusions from the no-intervention risk assessment. First, some maintenance and operations activities at Hanford must be continued to protect the public from grave risks. However, when large Hanford expenditures are compared to cleanup progress, funds expended for maintenance and operations must be put in proper perspective. Second, stakeholder's emphasis on public risks at Hanford, as indicated by remediation priorities, are not in line with those estimated. The focus currently is on compliance with regulations, and on dealing with issues which are visible to stakeholders

Chemical Risk Assessment

Science.gov (United States)

This course is aimed at providing an overview of the fundamental guiding principles and general methods used in chemical risk assessment. Chemical risk assessment is a complex and ever-evolving process. These principles and methods have been organized by the National Research Cou...

Lessons learned: Needs for improving human health risk assessment at USDOE Sites

International Nuclear Information System (INIS)

Hamilton, L.D.; Holtzman, S.; Meinhold, A.F.; Morris, S.C.; Rowe, M.D.; Daniels, J.I.; Layton, D.W.; Anspaugh, L.R.

1993-09-01

Realistic health risk assessments were performed in a pilot study of three U.S. Department of Energy (USDOE) sites. These assessments, covering a broad spectrum of data and methods, were used to identify needs for improving future health risk assessments at USDOE sites. Topics receiving specific recommendations for additional research include: choice of distributions for Monte Carlo simulation; estimation of risk reduction; analysis of the U.S. Department of Agriculture Database on food and nutrient intakes; investigations on effects of food processing on contaminant levels; background food and environmental concentrations of contaminants; method for handling exposures to groundwater plumes, methods for analyzing less than lifetime exposure to carcinogens; and improvement of bioaccumulation factors

Network Security Risk Assessment System Based on Attack Graph and Markov Chain

Science.gov (United States)

Sun, Fuxiong; Pi, Juntao; Lv, Jin; Cao, Tian

2017-10-01

Network security risk assessment technology can be found in advance of the network problems and related vulnerabilities, it has become an important means to solve the problem of network security. Based on attack graph and Markov chain, this paper provides a Network Security Risk Assessment Model (NSRAM). Based on the network infiltration tests, NSRAM generates the attack graph by the breadth traversal algorithm. Combines with the international standard CVSS, the attack probability of atomic nodes are counted, and then the attack transition probabilities of ones are calculated by Markov chain. NSRAM selects the optimal attack path after comprehensive measurement to assessment network security risk. The simulation results show that NSRAM can reflect the actual situation of network security objectively.

An integrated risk assessment approach: Risk assessment in the programmatic environmental impact statement

International Nuclear Information System (INIS)

Morris, J.M.

1994-01-01

The following paper is an informal summary of salient points made in the presentation entitled open-quotes An Integrated Risk Assessment Approach: Risk Assessment in the Programmatic Environmental Impact Statement (PEIS).close quotes. This presentation was given at the U.S. DOE Integrated Planning Workshop in Denver, Colorado on June 2, 1994. Integrated decision analysis is very important in environmental restoration and waste management in the evaluation of such things as land use planning, waste load forecasting, cost analyses, and technology development activities. Integrated risk assessment is an approach that addresses multiple components of risk, including: risks from surplus facilities as well as typical environmental restoration sites, risks to the public, risks to workers, ecological risk, risks before, during and after remediation activities, and others

The relation of risk assessment and health impact assessment

DEFF Research Database (Denmark)

Ádám, Balázs; Gulis, Gabriel

2013-01-01

than assessing a present situation. As part of this process, however, methods applied in risk assessment are used. Risk assessment typically characterises relation of a well-defined risk factor to a well-defined health outcome. Within HIA usually several individual risk assessments are needed...... of the causal chain from the proposal through related health determinants and risk factors to health outcomes. The stepwise analysis, systematic prioritization and consideration of horizontal interactions between the causal pathways make it feasible to use widely recognized risk assessment methods in the HIA......The level and distribution of health risks in a society is substantially influenced by measures of various policies, programmes or projects. Risk assessment can evaluate the nature, likelihood and severity of an adverse effect. Health impact assessment (HIA) provides similar function when used...

Benchmarking computational fluid dynamics models of lava flow simulation for hazard assessment, forecasting, and risk management

Science.gov (United States)

Dietterich, Hannah; Lev, Einat; Chen, Jiangzhi; Richardson, Jacob A.; Cashman, Katharine V.

2017-01-01

Numerical simulations of lava flow emplacement are valuable for assessing lava flow hazards, forecasting active flows, designing flow mitigation measures, interpreting past eruptions, and understanding the controls on lava flow behavior. Existing lava flow models vary in simplifying assumptions, physics, dimensionality, and the degree to which they have been validated against analytical solutions, experiments, and natural observations. In order to assess existing models and guide the development of new codes, we conduct a benchmarking study of computational fluid dynamics (CFD) models for lava flow emplacement, including VolcFlow, OpenFOAM, FLOW-3D, COMSOL, and MOLASSES. We model viscous, cooling, and solidifying flows over horizontal planes, sloping surfaces, and into topographic obstacles. We compare model results to physical observations made during well-controlled analogue and molten basalt experiments, and to analytical theory when available. Overall, the models accurately simulate viscous flow with some variability in flow thickness where flows intersect obstacles. OpenFOAM, COMSOL, and FLOW-3D can each reproduce experimental measurements of cooling viscous flows, and OpenFOAM and FLOW-3D simulations with temperature-dependent rheology match results from molten basalt experiments. We assess the goodness-of-fit of the simulation results and the computational cost. Our results guide the selection of numerical simulation codes for different applications, including inferring emplacement conditions of past lava flows, modeling the temporal evolution of ongoing flows during eruption, and probabilistic assessment of lava flow hazard prior to eruption. Finally, we outline potential experiments and desired key observational data from future flows that would extend existing benchmarking data sets.

Assessment of cardiovascular risk.

LENUS (Irish Health Repository)

Cooney, Marie Therese

2010-10-01

Atherosclerotic cardiovascular disease (CVD) is the most common cause of death worldwide. Usually atherosclerosis is caused by the combined effects of multiple risk factors. For this reason, most guidelines on the prevention of CVD stress the assessment of total CVD risk. The most intensive risk factor modification can then be directed towards the individuals who will derive the greatest benefit. To assist the clinician in calculating the effects of these multiple interacting risk factors, a number of risk estimation systems have been developed. This review address several issues regarding total CVD risk assessment: Why should total CVD risk be assessed? What risk estimation systems are available? How well do these systems estimate risk? What are the advantages and disadvantages of the current systems? What are the current limitations of risk estimation systems and how can they be resolved? What new developments have occurred in CVD risk estimation?

A dynamic multimedia fuzzy-stochastic integrated environmental risk assessment approach for contaminated sites management

Energy Technology Data Exchange (ETDEWEB)

Hu, Yan; Wen, Jing-ya; Li, Xiao-li; Wang, Da-zhou; Li, Yu, E-mail: liyuxx8@hotmail.com

2013-10-15

Highlights: • Using interval mathematics to describe spatial and temporal variability and parameter uncertainty. • Using fuzzy theory to quantify variability of environmental guideline values. • Using probabilistic approach to integrate interval concentrations and fuzzy environmental guideline. • Establishment of dynamic multimedia environmental integrated risk assessment framework. -- Abstract: A dynamic multimedia fuzzy-stochastic integrated environmental risk assessment approach was developed for contaminated sites management. The contaminant concentrations were simulated by a validated interval dynamic multimedia fugacity model, and different guideline values for the same contaminant were represented as a fuzzy environmental guideline. Then, the probability of violating environmental guideline (Pv) can be determined by comparison between the modeled concentrations and the fuzzy environmental guideline, and the constructed relationship between the Pvs and environmental risk levels was used to assess the environmental risk level. The developed approach was applied to assess the integrated environmental risk at a case study site in China, simulated from 1985 to 2020. Four scenarios were analyzed, including “residential land” and “industrial land” environmental guidelines under “strict” and “loose” strictness. It was found that PAH concentrations will increase steadily over time, with soil found to be the dominant sink. Source emission in soil was the leading input and atmospheric sedimentation was the dominant transfer process. The integrated environmental risks primarily resulted from petroleum spills and coke ovens, while the soil environmental risks came from coal combustion. The developed approach offers an effective tool for quantifying variability and uncertainty in the dynamic multimedia integrated environmental risk assessment and the contaminated site management.

A dynamic multimedia fuzzy-stochastic integrated environmental risk assessment approach for contaminated sites management

International Nuclear Information System (INIS)

Hu, Yan; Wen, Jing-ya; Li, Xiao-li; Wang, Da-zhou; Li, Yu

2013-01-01

Highlights: • Using interval mathematics to describe spatial and temporal variability and parameter uncertainty. • Using fuzzy theory to quantify variability of environmental guideline values. • Using probabilistic approach to integrate interval concentrations and fuzzy environmental guideline. • Establishment of dynamic multimedia environmental integrated risk assessment framework. -- Abstract: A dynamic multimedia fuzzy-stochastic integrated environmental risk assessment approach was developed for contaminated sites management. The contaminant concentrations were simulated by a validated interval dynamic multimedia fugacity model, and different guideline values for the same contaminant were represented as a fuzzy environmental guideline. Then, the probability of violating environmental guideline (Pv) can be determined by comparison between the modeled concentrations and the fuzzy environmental guideline, and the constructed relationship between the Pvs and environmental risk levels was used to assess the environmental risk level. The developed approach was applied to assess the integrated environmental risk at a case study site in China, simulated from 1985 to 2020. Four scenarios were analyzed, including “residential land” and “industrial land” environmental guidelines under “strict” and “loose” strictness. It was found that PAH concentrations will increase steadily over time, with soil found to be the dominant sink. Source emission in soil was the leading input and atmospheric sedimentation was the dominant transfer process. The integrated environmental risks primarily resulted from petroleum spills and coke ovens, while the soil environmental risks came from coal combustion. The developed approach offers an effective tool for quantifying variability and uncertainty in the dynamic multimedia integrated environmental risk assessment and the contaminated site management

Simulation to aid in interpreting biological relevance and setting of population-level protection goals for risk assessment of pesticides.

Science.gov (United States)

Topping, Christopher John; Luttik, Robert

2017-10-01

Specific protection goals (SPGs) comprise an explicit expression of the environmental components that need protection and the maximum impacts that can be tolerated. SPGs are set by risk managers and are typically based on protecting populations or functions. However, the measurable endpoints available to risk managers, at least for vertebrates, are typically laboratory tests. We demonstrate, using the example of eggshell thinning in skylarks, how simulation can be used to place laboratory endpoints in context of population-level effects as an aid to setting the SPGs. We develop explanatory scenarios investigating the impact of different assumptions of eggshell thinning on skylark population size, density and distribution in 10 Danish landscapes, chosen to represent the range of typical Danish agricultural conditions. Landscape and timing of application of the pesticide were found to be the most critical factors to consider in the impact assessment. Consequently, a regulatory scenario of monoculture spring barley with an early spray treatment eliciting the eggshell thinning effect was applied using concentrations eliciting effects of zero to 100% in steps of 5%. Setting the SPGs requires balancing scientific, social and political realities. However, the provision of clear and detailed options such as those from comprehensive simulation results can inform the decision process by improving transparency and by putting the more abstract testing data into the context of real-world impacts. Copyright © 2017 Elsevier Inc. All rights reserved.

Risk assessment of storm surge disaster based on numerical models and remote sensing

Science.gov (United States)

Liu, Qingrong; Ruan, Chengqing; Zhong, Shan; Li, Jian; Yin, Zhonghui; Lian, Xihu

2018-06-01

Storm surge is one of the most serious ocean disasters in the world. Risk assessment of storm surge disaster for coastal areas has important implications for planning economic development and reducing disaster losses. Based on risk assessment theory, this paper uses coastal hydrological observations, a numerical storm surge model and multi-source remote sensing data, proposes methods for valuing hazard and vulnerability for storm surge and builds a storm surge risk assessment model. Storm surges in different recurrence periods are simulated in numerical models and the flooding areas and depth are calculated, which are used for assessing the hazard of storm surge; remote sensing data and GIS technology are used for extraction of coastal key objects and classification of coastal land use are identified, which is used for vulnerability assessment of storm surge disaster. The storm surge risk assessment model is applied for a typical coastal city, and the result shows the reliability and validity of the risk assessment model. The building and application of storm surge risk assessment model provides some basis reference for the city development plan and strengthens disaster prevention and mitigation.

Update earthquake risk assessment in Cairo, Egypt

Science.gov (United States)

Badawy, Ahmed; Korrat, Ibrahim; El-Hadidy, Mahmoud; Gaber, Hanan

2017-07-01

The Cairo earthquake (12 October 1992; m b = 5.8) is still and after 25 years one of the most painful events and is dug into the Egyptians memory. This is not due to the strength of the earthquake but due to the accompanied losses and damages (561 dead; 10,000 injured and 3000 families lost their homes). Nowadays, the most frequent and important question that should rise is "what if this earthquake is repeated today." In this study, we simulate the same size earthquake (12 October 1992) ground motion shaking and the consequent social-economic impacts in terms of losses and damages. Seismic hazard, earthquake catalogs, soil types, demographics, and building inventories were integrated into HAZUS-MH to produce a sound earthquake risk assessment for Cairo including economic and social losses. Generally, the earthquake risk assessment clearly indicates that "the losses and damages may be increased twice or three times" in Cairo compared to the 1992 earthquake. The earthquake risk profile reveals that five districts (Al-Sahel, El Basateen, Dar El-Salam, Gharb, and Madinat Nasr sharq) lie in high seismic risks, and three districts (Manshiyat Naser, El-Waily, and Wassat (center)) are in low seismic risk level. Moreover, the building damage estimations reflect that Gharb is the highest vulnerable district. The analysis shows that the Cairo urban area faces high risk. Deteriorating buildings and infrastructure make the city particularly vulnerable to earthquake risks. For instance, more than 90 % of the estimated buildings damages are concentrated within the most densely populated (El Basateen, Dar El-Salam, Gharb, and Madinat Nasr Gharb) districts. Moreover, about 75 % of casualties are in the same districts. Actually, an earthquake risk assessment for Cairo represents a crucial application of the HAZUS earthquake loss estimation model for risk management. Finally, for mitigation, risk reduction, and to improve the seismic performance of structures and assure life safety

A spatially-evaluated methodology for assessing risk to a population from contaminated land

International Nuclear Information System (INIS)

Gay, J. Rebecca; Korre, Anna

2006-01-01

A methodology is proposed which combines quantitative probabilistic human health risk assessment and spatial statistical methods (geostatistics) to produce an assessment of risks to human health from exposure to contaminated land, in a manner which preserves the spatial distribution of risks and provides a measure of uncertainty in the assessment. Maps of soil contaminant levels, which incorporate uncertainty, are produced from sparse sample data using sequential indicator simulation. A real, age-stratified population is mapped across the contaminated area, and intake of soil contaminants by individuals is calculated probabilistically using an adaptation of the Contaminated Land Exposure Assessment (CLEA) model. An abundance of information is contained in results which can be interrogated at the population and individual level, and mapped to provide a powerful visual tool for risk managers, enabling efficient targeting of risk reduction measures to different locations. - A methodology for calculating and mapping risks to a population from intake of soil contaminants

Determining procedures for simulation-based training in radiology: a nationwide needs assessment.

Science.gov (United States)

Nayahangan, Leizl Joy; Nielsen, Kristina Rue; Albrecht-Beste, Elisabeth; Bachmann Nielsen, Michael; Paltved, Charlotte; Lindorff-Larsen, Karen Gilboe; Nielsen, Bjørn Ulrik; Konge, Lars

2018-01-09

New training modalities such as simulation are widely accepted in radiology; however, development of effective simulation-based training programs is challenging. They are often unstructured and based on convenience or coincidence. The study objective was to perform a nationwide needs assessment to identify and prioritize technical procedures that should be included in a simulation-based curriculum. A needs assessment using the Delphi method was completed among 91 key leaders in radiology. Round 1 identified technical procedures that radiologists should learn. Round 2 explored frequency of procedure, number of radiologists performing the procedure, risk and/or discomfort for patients, and feasibility for simulation. Round 3 was elimination and prioritization of procedures. Response rates were 67 %, 70 % and 66 %, respectively. In Round 1, 22 technical procedures were included. Round 2 resulted in pre-prioritization of procedures. In round 3, 13 procedures were included in the final prioritized list. The three highly prioritized procedures were ultrasound-guided (US) histological biopsy and fine-needle aspiration, US-guided needle puncture and catheter drainage, and basic abdominal ultrasound. A needs assessment identified and prioritized 13 technical procedures to include in a simulation-based curriculum. The list may be used as guide for development of training programs. • Simulation-based training can supplement training on patients in radiology. • Development of simulation-based training should follow a structured approach. • The CAMES Needs Assessment Formula explores needs for simulation training. • A national Delphi study identified and prioritized procedures suitable for simulation training. • The prioritized list serves as guide for development of courses in radiology.

Hydrological Modelling using HEC-HMS for Flood Risk Assessment of Segamat Town, Malaysia

Science.gov (United States)

Romali, N. S.; Yusop, Z.; Ismail, A. Z.

2018-03-01

This paper presents an assessment of the applicability of using Hydrologic Modelling System developed by the Hydrologic Engineering Center (HEC-HMS) for hydrological modelling of Segamat River. The objective of the model application is to assist in the assessment of flood risk by providing the peak flows of 2011 Segamat flood for the generation of flood mapping of Segamat town. The capability of the model was evaluated by comparing the historical observed data with the simulation results of the selected flood events. The model calibration and validation efficiency was verified using Nash-Sutcliffe model efficiency coefficient. The results demonstrate the interest to implement the hydrological model for assessing flood risk where the simulated peak flow result is in agreement with historical observed data. The model efficiency of the calibrated and validated exercises is 0.90 and 0.76 respectively, which is acceptable.

Information needs for risk assessment

Energy Technology Data Exchange (ETDEWEB)

DeRosa, C.T.; Choudhury, H.; Schoeny, R.S.

1990-12-31

Risk assessment can be thought of as a conceptual approach to bridge the gap between the available data and the ultimate goal of characterizing the risk or hazard associated with a particular environmental problem. To lend consistency to and to promote quality in the process, the US Environmental Protection Agency (EPA) published Guidelines for Risk Assessment of Carcinogenicity, Developmental Toxicity, Germ Cell Mutagenicity and Exposure Assessment, and Risk Assessment of Chemical Mixtures. The guidelines provide a framework for organizing the information, evaluating data, and for carrying out the risk assessment in a scientifically plausible manner. In the absence of sufficient scientific information or when abundant data are available, the guidelines provide alternative methodologies that can be employed in the risk assessment. 4 refs., 3 figs., 2 tabs.

Probabilistic risk assessment as an aid to risk management

International Nuclear Information System (INIS)

Garrick, B.J.

1982-01-01

Probabilistic risk assessments are providing important insights into nuclear power plant safety. Their value is two-fold: first as a means of quantifying nuclear plant risk including contributors to risk, and second as an aid to risk management. A risk assessment provides an analytical plant model that can be the basis for performing meaningful decision analyses for controlling safety. It is the aspect of quantitative risk management that makes probabilistic risk assessment an important technical discipline of the future

Dynamic Bayesian Networks for Context-Aware Fall Risk Assessment

Directory of Open Access Journals (Sweden)

Gregory Koshmak

2014-05-01

Full Text Available Fall incidents among the elderly often occur in the home and can cause serious injuries affecting their independent living. This paper presents an approach where data from wearable sensors integrated in a smart home environment is combined using a dynamic Bayesian network. The smart home environment provides contextual data, obtained from environmental sensors, and contributes to assessing a fall risk probability. The evaluation of the developed system is performed through simulation. Each time step is represented by a single user activity and interacts with a fall sensors located on a mobile device. A posterior probability is calculated for each recognized activity or contextual information. The output of the system provides a total risk assessment of falling given a response from the fall sensor.

Risk assessment by dynamic representation of vulnerability, exploitation, and impact

Science.gov (United States)

Cam, Hasan

2015-05-01

Assessing and quantifying cyber risk accurately in real-time is essential to providing security and mission assurance in any system and network. This paper presents a modeling and dynamic analysis approach to assessing cyber risk of a network in real-time by representing dynamically its vulnerabilities, exploitations, and impact using integrated Bayesian network and Markov models. Given the set of vulnerabilities detected by a vulnerability scanner in a network, this paper addresses how its risk can be assessed by estimating in real-time the exploit likelihood and impact of vulnerability exploitation on the network, based on real-time observations and measurements over the network. The dynamic representation of the network in terms of its vulnerabilities, sensor measurements, and observations is constructed dynamically using the integrated Bayesian network and Markov models. The transition rates of outgoing and incoming links of states in hidden Markov models are used in determining exploit likelihood and impact of attacks, whereas emission rates help quantify the attack states of vulnerabilities. Simulation results show the quantification and evolving risk scores over time for individual and aggregated vulnerabilities of a network.

Wildfire Risk Assessment in a Typical Mediterranean Wildland-Urban Interface of Greece

Science.gov (United States)

Mitsopoulos, Ioannis; Mallinis, Giorgos; Arianoutsou, Margarita

2015-04-01

The purpose of this study was to assess spatial wildfire risk in a typical Mediterranean wildland-urban interface (WUI) in Greece and the potential effect of three different burning condition scenarios on the following four major wildfire risk components: burn probability, conditional flame length, fire size, and source-sink ratio. We applied the Minimum Travel Time fire simulation algorithm using the FlamMap and ArcFuels tools to characterize the potential response of the wildfire risk to a range of different burning scenarios. We created site-specific fuel models of the study area by measuring the field fuel parameters in representative natural fuel complexes, and we determined the spatial extent of the different fuel types and residential structures in the study area using photointerpretation procedures of large scale natural color orthophotographs. The results included simulated spatially explicit fire risk components along with wildfire risk exposure analysis and the expected net value change. Statistical significance differences in simulation outputs between the scenarios were obtained using Tukey's significance test. The results of this study provide valuable information for decision support systems for short-term predictions of wildfire risk potential and inform wildland fire management of typical WUI areas in Greece.

Wildfire risk assessment in a typical Mediterranean wildland-urban interface of Greece.

Science.gov (United States)

Mitsopoulos, Ioannis; Mallinis, Giorgos; Arianoutsou, Margarita

2015-04-01

The purpose of this study was to assess spatial wildfire risk in a typical Mediterranean wildland-urban interface (WUI) in Greece and the potential effect of three different burning condition scenarios on the following four major wildfire risk components: burn probability, conditional flame length, fire size, and source-sink ratio. We applied the Minimum Travel Time fire simulation algorithm using the FlamMap and ArcFuels tools to characterize the potential response of the wildfire risk to a range of different burning scenarios. We created site-specific fuel models of the study area by measuring the field fuel parameters in representative natural fuel complexes, and we determined the spatial extent of the different fuel types and residential structures in the study area using photointerpretation procedures of large scale natural color orthophotographs. The results included simulated spatially explicit fire risk components along with wildfire risk exposure analysis and the expected net value change. Statistical significance differences in simulation outputs between the scenarios were obtained using Tukey's significance test. The results of this study provide valuable information for decision support systems for short-term predictions of wildfire risk potential and inform wildland fire management of typical WUI areas in Greece.

Assessing risks for integrated water resource management: coping with uncertainty and the human factor

Directory of Open Access Journals (Sweden)

M. J. Polo

2014-09-01

Full Text Available Risk assessment for water resource planning must deal with the uncertainty associated with excess/scarcity situations and their costs. The projected actions for increasing water security usually involve an indirect "call-effect": the territory occupation/water use is increased following the achieved protection. In this work, flood and water demand in a mountainous semi-arid watershed in southern Spain are assessed by means of the stochastic simulation of extremes, when this human factor is/is not considered. The results show how not including this call-effect induced an underestimation of flood risk after protecting the floodplain of between 35 and 78 % in a 35-year planning horizon. Similarly, the pursued water availability of a new reservoir resulted in a 10-year scarcity risk increase up to 38 % when the trend of expanding the irrigated area was included in the simulations. These results highlight the need for including this interaction in the decision-making assessment.

Simulating Performance Risk for Lighting Retrofit Decisions

Directory of Open Access Journals (Sweden)

Jia Hu

2015-05-01

Full Text Available In building retrofit projects, dynamic simulations are performed to simulate building performance. Uncertainty may negatively affect model calibration and predicted lighting energy savings, which increases the chance of default on performance-based contracts. Therefore, the aim of this paper is to develop a simulation-based method that can analyze lighting performance risk in lighting retrofit decisions. The model uses a surrogate model, which is constructed by adaptively selecting sample points and generating approximation surfaces with fast computing time. The surrogate model is a replacement of the computation intensive process. A statistical method is developed to generate extreme weather profile based on the 20-year historical weather data. A stochastic occupancy model was created using actual occupancy data to generate realistic occupancy patterns. Energy usage of lighting, and heating, ventilation, and air conditioning (HVAC is simulated using EnergyPlus. The method can evaluate the influence of different risk factors (e.g., variation of luminaire input wattage, varying weather conditions on lighting and HVAC energy consumption and lighting electricity demand. Probability distributions are generated to quantify the risk values. A case study was conducted to demonstrate and validate the methods. The surrogate model is a good solution for quantifying the risk factors and probability distribution of the building performance.

Tsunami risk mapping simulation for Malaysia

Science.gov (United States)

Teh, S.Y.; Koh, H. L.; Moh, Y.T.; De Angelis, D. L.; Jiang, J.

2011-01-01

The 26 December 2004 Andaman mega tsunami killed about a quarter of a million people worldwide. Since then several significant tsunamis have recurred in this region, including the most recent 25 October 2010 Mentawai tsunami. These tsunamis grimly remind us of the devastating destruction that a tsunami might inflict on the affected coastal communities. There is evidence that tsunamis of similar or higher magnitudes might occur again in the near future in this region. Of particular concern to Malaysia are tsunamigenic earthquakes occurring along the northern part of the Sunda Trench. Further, the Manila Trench in the South China Sea has been identified as another source of potential tsunamigenic earthquakes that might trigger large tsunamis. To protect coastal communities that might be affected by future tsunamis, an effective early warning system must be properly installed and maintained to provide adequate time for residents to be evacuated from risk zones. Affected communities must be prepared and educated in advance regarding tsunami risk zones, evacuation routes as well as an effective evacuation procedure that must be taken during a tsunami occurrence. For these purposes, tsunami risk zones must be identified and classified according to the levels of risk simulated. This paper presents an analysis of tsunami simulations for the South China Sea and the Andaman Sea for the purpose of developing a tsunami risk zone classification map for Malaysia based upon simulated maximum wave heights. ?? 2011 WIT Press.

Real-time Risk Assessment for Aids to Navigation Using Fuzzy-FSA on Three-Dimensional Simulation System

OpenAIRE

Jinbiao Chen; Chaojian Shi; Dongxing Jia

2014-01-01

The risk level of the Aids to Navigation (AtoNs) can reflect the ship navigation safety level in the channel to some extent. In order to appreciate the risk level of the aids to navigation (AtoNs) in a navigation channel and to provide some decision-making suggestions for the AtoNs Maintenance and Management Department, the risk assessment index system of the AtoNs was built considering the advanced experience of IALA. Under the Formal Safety Assessment frame, taking the advantages of the fuz...

Methodology of environmental risk assessment management

Directory of Open Access Journals (Sweden)

Saša T. Bakrač

2012-04-01

Full Text Available Successful protection of environment is mostly based on high-quality assessment of potential and present risks. Environmental risk management is a complex process which includes: identification, assessment and control of risk, namely taking measures in order to minimize the risk to an acceptable level. Environmental risk management methodology: In addition to these phases in the management of environmental risk, appropriate measures that affect the reduction of risk occurrence should be implemented: - normative and legal regulations (laws and regulations, - appropriate organizational structures in society, and - establishing quality monitoring of environment. The emphasis is placed on the application of assessment methodologies (three-model concept, as the most important aspect of successful management of environmental risk. Risk assessment methodology - European concept: The first concept of ecological risk assessment methodology is based on the so-called European model-concept. In order to better understand this ecological risk assessment methodology, two concepts - hazard and risk - are introduced. The European concept of environmental risk assessment has the following phases in its implementation: identification of hazard (danger, identification of consequences (if there is hazard, estimate of the scale of consequences, estimate of consequence probability and risk assessment (also called risk characterization. The European concept is often used to assess risk in the environment as a model for addressing the distribution of stressors along the source - path - receptor line. Risk assessment methodology - Canadian concept: The second concept of the methodology of environmental risk assessment is based on the so-called Canadian model-concept. The assessment of ecological risk includes risk arising from natural events (floods, extreme weather conditions, etc., technological processes and products, agents (chemical, biological, radiological, etc

Risk assessment in spent fuel storage and transportation

International Nuclear Information System (INIS)

Pandimani, S.

1989-01-01

Risk assessment in various stages of nuclear fuel cycle is still an active area of Nuclear safety studies. From the results of risk assessment available in literature, it can be determined that the risk resulting from shipments of plutonium and spent-fuel are much greater than that resulting from the transport of other materials within the nuclear fuel cycle. In India spent fuels are kept in Spent Fuel Storage Pool (SFSP) for about 240-400 days, which is relatively a longer period compared to the usual 120 days as recommended by regulatory authorities. After cooling spent fuels are transported to the reprocessing sites which are mostly situated close to the plants. India has two high level waste treatment facilities, one PREFRE (Plutonium Reprocessing and Fuel Recycling) at Tarapur and the other one, a unit of Nuclear Fuel Complex at Hyderabad. This paper presents the risk associated with spent fuel storage and transportation for the Indian conditions. All calculations are based on a typical CANDU reactor system. Simple fault tree models are evolved for SFSP and for Transportation Accident Mode (TAM) for both road and rail. Fault tree quantification and risk assessment are done to each of these models. All necessary data for SFSP are taken mostly from Reactor Safety Study, (1975). Similarly, the data for rail TAM are taken from Annual Statistical Statements, (1987-8) and that for road TAM from Special Issue on Motor Vehicle Accident Statistics in India, (1986). Simulation method is used wherever necessary. Risk is also estimated for normal/accident free transport

Strategic Risk Assessment

Science.gov (United States)

Derleth, Jason; Lobia, Marcus

2009-01-01

This slide presentation provides an overview of the attempt to develop and demonstrate a methodology for the comparative assessment of risks across the entire portfolio of NASA projects and assets. It includes information about strategic risk identification, normalizing strategic risks, calculation of relative risk score, and implementation options.

Overview of risk assessment

International Nuclear Information System (INIS)

Rimington, J.D.

1992-01-01

The paper begins by defining some terms, and then refer to a number of technical and other difficulties. Finally it attempts to set out why risk assessment is important and what its purposes are. 2) First, risk and risk assessment - what are they?. 3) Risk is a subject of universal significance. Life is very uncertain, and we can achieve no object or benefit in it except by approaching nearer to particular hazards which lie between us and our objects. That approach represents acceptance of risk. 4) Risk assessment is a way of systematising our approach to hazard with a view to determining what is more and what is less risky. It helps us in the end to diminish our exposure while obtaining whatever benefits we have in mind, or to optimise the risks and the benefits

Overview of risk assessment

Energy Technology Data Exchange (ETDEWEB)

Rimington, J D [Health and Safety Executive (United Kingdom)

1992-07-01

The paper begins by defining some terms, and then refer to a number of technical and other difficulties. Finally it attempts to set out why risk assessment is important and what its purposes are. 2) First, risk and risk assessment - what are they?. 3) Risk is a subject of universal significance. Life is very uncertain, and we can achieve no object or benefit in it except by approaching nearer to particular hazards which lie between us and our objects. That approach represents acceptance of risk. 4) Risk assessment is a way of systematising our approach to hazard with a view to determining what is more and what is less risky. It helps us in the end to diminish our exposure while obtaining whatever benefits we have in mind, or to optimise the risks and the benefits.

[Urban ecological risk assessment: a review].

Science.gov (United States)

Wang, Mei-E; Chen, Wei-Ping; Peng, Chi

2014-03-01

With the development of urbanization and the degradation of urban living environment, urban ecological risks caused by urbanization have attracted more and more attentions. Based on urban ecology principles and ecological risk assessment frameworks, contents of urban ecological risk assessment were reviewed in terms of driven forces, risk resources, risk receptors, endpoints and integrated approaches for risk assessment. It was suggested that types and degrees of urban economical and social activities were the driven forces for urban ecological risks. Ecological functional components at different levels in urban ecosystems as well as the urban system as a whole were the risk receptors. Assessment endpoints involved in changes of urban ecological structures, processes, functional components and the integrity of characteristic and function. Social-ecological models should be the major approaches for urban ecological risk assessment. Trends for urban ecological risk assessment study should focus on setting a definite protection target and criteria corresponding to assessment endpoints, establishing a multiple-parameter assessment system and integrative assessment approaches.

Tackling Biocomplexity with Meta-models for Species Risk Assessment

Directory of Open Access Journals (Sweden)

Philip J. Nyhus

2007-06-01

Full Text Available We describe results of a multi-year effort to strengthen consideration of the human dimension into endangered species risk assessments and to strengthen research capacity to understand biodiversity risk assessment in the context of coupled human-natural systems. A core group of social and biological scientists have worked with a network of more than 50 individuals from four countries to develop a conceptual framework illustrating how human-mediated processes influence biological systems and to develop tools to gather, translate, and incorporate these data into existing simulation models. A central theme of our research focused on (1 the difficulties often encountered in identifying and securing diverse bodies of expertise and information that is necessary to adequately address complex species conservation issues; and (2 the development of quantitative simulation modeling tools that could explicitly link these datasets as a way to gain deeper insight into these issues. To address these important challenges, we promote a "meta-modeling" approach where computational links are constructed between discipline-specific models already in existence. In this approach, each model can function as a powerful stand-alone program, but interaction between applications is achieved by passing data structures describing the state of the system between programs. As one example of this concept, an integrated meta-model of wildlife disease and population biology is described. A goal of this effort is to improve science-based capabilities for decision making by scientists, natural resource managers, and policy makers addressing environmental problems in general, and focusing on biodiversity risk assessment in particular.

Prioritization Risk Integration Simulation Model (PRISM) For Environmental Remediation and Waste Management - 12097

Energy Technology Data Exchange (ETDEWEB)

Pentz, David L.; Stoll, Ralph H.; Greeves, John T. [Predicus LLC, Issaquah, WA 98027 (United States); Miller, R. Ian [GoldSim Technology Group, LLC, Issaquah, WA 98027 (United States); Nutt, W. Mark [Argonne National Laboratory, Argonne, IL 60439 (United States)

2012-07-01

that is widely used for risk and performance assessment calculations. PRISM can be run in a deterministic mode, which quickly provides an estimate of the most likely results of a given plan. Alternatively, the model can be run probabilistically in a Monte Carlo mode, exploring the risks and uncertainties in the system and producing probability distributions for the different performance measures. The PRISM model demonstrates how EM can evaluate a portfolio of ELOs, and transform the ELOs from their current conditions to acceptable conditions, utilizing different strategic approaches. There are many types of ELOs - contaminated soils and groundwater plumes, disused facilities awaiting D and D, and various types of wastes waiting for processing or disposal. This scope of work for the PRISM process and the development of a dynamic simulation model are a logical extension of the GoldSim simulation software used by the OCRWM to assess the long-term performance for the Yucca Mountain Project and by NNSA to assess project risk at its sites. Systems integration modeling will promote better understanding of all project risks, technical and nontechnical, and more defensible decision-making for complex projects with significant uncertainties. It can provide effective visual communication and rapid adaptation during interactions with stakeholders (Administration, Congress, State, Local, and NGO). It will also allow rapid assessment of alternative management approaches. (authors)

A simulation model of IT risk on program trading

Science.gov (United States)

Xia, Bingying; Jiang, Wenbao; Luo, Guangxuan

2015-12-01

The biggest difficulty for Program trading IT risk measures lies in the loss of data, in view of this situation, the current scholars approach is collecting court, network and other public media such as all kinds of accident of IT both at home and abroad for data collection, and the loss of IT risk quantitative analysis based on this database. However, the IT risk loss database established by this method can only fuzzy reflect the real situation and not for real to make fundamental explanation. In this paper, based on the study of the concept and steps of the MC simulation, we use computer simulation method, by using the MC simulation method in the "Program trading simulation system" developed by team to simulate the real programming trading and get the IT risk loss of data through its IT failure experiment, at the end of the article, on the effectiveness of the experimental data is verified. In this way, better overcome the deficiency of the traditional research method and solves the problem of lack of IT risk data in quantitative research. More empirically provides researchers with a set of simulation method are used to study the ideas and the process template.

[Forensic assessment of violence risk].

Science.gov (United States)

Pujol Robinat, Amadeo; Mohíno Justes, Susana; Gómez-Durán, Esperanza L

2014-03-01

Over the last 20 years there have been steps forward in the field of scientific research on prediction and handling different violent behaviors. In this work we go over the classic concept of "criminal dangerousness" and the more current of "violence risk assessment". We analyze the evolution of such assessment from the practice of non-structured clinical expert opinion to current actuarial methods and structured clinical expert opinion. Next we approach the problem of assessing physical violence risk analyzing the HCR-20 (Assessing Risk for Violence) and we also review the classic and complex subject of the relation between mental disease and violence. One of the most problematic types of violence, difficult to assess and predict, is sexual violence. We study the different actuarial and sexual violence risk prediction instruments and in the end we advise an integral approach to the problem. We also go through partner violence risk assessment, describing the most frequently used scales, especially SARA (Spouse Assault Risk Assessment) and EPV-R. Finally we give practical advice on risk assessment, emphasizing the importance of having maximum information about the case, carrying out a clinical examination, psychopathologic exploration and the application of one of the described risk assessment scales. We'll have to express an opinion about the dangerousness/risk of future violence from the subject and some recommendations on the conduct to follow and the most advisable treatment. Copyright © 2014 Elsevier España, S.L. All rights reserved.

Risk Assessment and Integration Team (RAIT) Portfolio Risk Analysis Strategy

Science.gov (United States)

Edwards, Michelle

2010-01-01

Impact at management level: Qualitative assessment of risk criticality in conjunction with risk consequence, likelihood, and severity enable development of an "investment policy" towards managing a portfolio of risks. Impact at research level: Quantitative risk assessments enable researchers to develop risk mitigation strategies with meaningful risk reduction results. Quantitative assessment approach provides useful risk mitigation information.

[Risk Assessment and Risk Management of Chemicals in China].

Science.gov (United States)

Wang, Tie-yu; Zhou, Yun-qiao; Li, Qi-feng; Lü, Yong-long

2016-02-15

Risk assessment and risk management have been increasingly approved as an effective approach for appropriate disposal and scientific management of chemicals. This study systematically analyzed the risk assessment methods of chemicals from three aspects including health risk, ecological risk and regional risk. Based on the current situation of classification and management towards chemicals in China, a specific framework of risk management on chemicals was proposed by selecting target chemicals, predominant industries and related stakeholders as the objects. The results of the present study will provide scientific support for improving risk assessment and reasonable management of chemicals in China.

Dynamic building risk assessment theoretic model for rainstorm-flood utilization ABM and ABS

Science.gov (United States)

Lai, Wenze; Li, Wenbo; Wang, Hailei; Huang, Yingliang; Wu, Xuelian; Sun, Bingyun

2015-12-01

Flood is one of natural disasters with the worst loss in the world. It needs to assess flood disaster risk so that we can reduce the loss of flood disaster. Disaster management practical work needs the dynamic risk results of building. Rainstorm flood disaster system is a typical complex system. From the view of complex system theory, flood disaster risk is the interaction result of hazard effect objects, rainstorm flood hazard factors, and hazard environments. Agent-based modeling (ABM) is an important tool for complex system modeling. Rainstorm-flood building risk dynamic assessment method (RFBRDAM) was proposed using ABM in this paper. The interior structures and procedures of different agents in proposed meth had been designed. On the Netlogo platform, the proposed method was implemented to assess the building risk changes of the rainstorm flood disaster in the Huaihe River Basin using Agent-based simulation (ABS). The results indicated that the proposed method can dynamically assess building risk of the whole process for the rainstorm flood disaster. The results of this paper can provide one new approach for flood disaster building risk dynamic assessment and flood disaster management.

Nuclear Computerized Library for Assessing Reactor Risk (NUCLARR)

International Nuclear Information System (INIS)

Gilmore, W.E.; Blackman, H.S.; Ryan, T.G.

1986-01-01

The Nuclear Computerized Library for Assessing Reactor Risk (NUCLARR) program is a multiyear effort sponsored by the NRC and is being conducted at the Idaho National Engineering Laboratory (INEL). The goal of this program is to establish and operate computerized data base management tools for the human reliability data bank specification developed by Comer and Donovan. The NRC and the risk analysis community recognized that implementing a fully functional library would not be feasible, or practical, without the aid of computerized tools for management and manipulation of its data sources. The end users of the NUCLARR can be classified into three categories according to specific needs. The first category is those users interested in reviewing individual data sources for a given situation. The second category of users selects multiple data sources for a specific case, summarizing the information, and performing comparative studies. The last category of users interfaces the NUCLARR with other programming applications, such as other data banks, and simulation models of risk assessment. Project status is provided in the paper

Use of Ground Motion Simulations of a Historical Earthquake for the Assessment of Past and Future Urban Risks

Science.gov (United States)

Kentel, E.; Çelik, A.; karimzadeh Naghshineh, S.; Askan, A.

2017-12-01

Erzincan city located in the Eastern part of Turkey at the conjunction of three active faults is one of the most hazardous regions in the world. In addition to several historical events, this city has experienced one of the largest earthquakes during the last century: The 27 December 1939 (Ms=8.0) event. With limited knowledge of the tectonic structure by then, the city center was relocated to the North after the 1939 earthquake by almost 5km, indeed closer to the existing major strike slip fault. This decision coupled with poor construction technologies, led to severe damage during a later event that occurred on 13 March 1992 (Mw=6.6). The 1939 earthquake occurred in the pre-instrumental era in the region with no available local seismograms whereas the 1992 event was only recorded by 3 nearby stations. There are empirical isoseismal maps from both events indicating indirectly the spatial distribution of the damage. In this study, we focus on this region and present a multidisciplinary approach to discuss the different components of uncertainties involved in the assessment and mitigation of seismic risk in urban areas. For this initial attempt, ground motion simulation of the 1939 event is performed to obtain the anticipated ground motions and shaking intensities. Using these quantified results along with the spatial distribution of the observed damage, the relocation decision is assessed and suggestions are provided for future large earthquakes to minimize potential earthquake risks.

Assessing suturing techniques using a virtual reality surgical simulator.

Science.gov (United States)

Kazemi, Hamed; Rappel, James K; Poston, Timothy; Hai Lim, Beng; Burdet, Etienne; Leong Teo, Chee

2010-09-01

Advantages of virtual-reality simulators surgical skill assessment and training include more training time, no risk to patient, repeatable difficulty level, reliable feedback, without the resource demands, and ethical issues of animal-based training. We tested this for a key subtask and showed a strong link between skill in the simulator and in reality. Suturing performance was assessed for four groups of participants, including experienced surgeons and naive subjects, on a custom-made virtual-reality simulator. Each subject tried the experiment 30 times using five different types of needles to perform a standardized suture placement task. Traditional metrics of performance as well as new metrics enabled by our system were proposed, and the data indicate difference between trained and untrained performance. In all traditional parameters such as time, number of attempts, and motion quantity, the medical surgeons outperformed the other three groups, though differences were not significant. However, motion smoothness, penetration and exit angles, tear size areas, and orientation change were statistically significant in the trained group when compared with untrained group. This suggests that these parameters can be used in virtual microsurgery training.

Toxicity assessment of simulated urban runoff containing polycyclic musks and cadmium in Carassius auratus using oxidative stress biomarkers

International Nuclear Information System (INIS)

Chen Fang; Gao Jie; Zhou Qixing

2012-01-01

The objective of this study was to assess potential toxic effects of simulated urban runoff on Carassius auratus using oxidative stress biomarkers. The activity of antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and the content of malondialdehyde (MDA) in the liver of C. auratus were analyzed after a 7-, 14- and 21-day exposure to simulated urban runoff containing galaxolide (HHCB) and cadmium (Cd). The results showed that the activity of antioxidant enzymes and the content of MDA increased significantly exposed to the simulated urban runoff containing HHCB alone or mixture of HHCB and Cd. The activity of the investigated enzymes and the content of MDA then returned to the blank level over a longer period of exposure. The oxidative stress could be obviously caused in the liver of C. auratus under the experimental conditions. This could provide useful information for toxic risk assessment of urban runoff. - Highlights: ► We assessed potential toxicity of urban runoff containing HHCB and Cd. ► Exposure of simulated urban runoff can caused oxidative stress in C. auratus liver. ► SOD and CAT are more sensitive than POD and more suitable for indicating the toxicity of urban runoff. ► The present study using oxidative stress biomarkers could provide useful information for toxic risk assessment of urban runoff. - Simulated urban runoff containing HHCB and Cd could cause oxidative stress on the liver of Carassius auratus, which could provide useful information for toxic risk assessment of urban runoff.

Spatial and Temporal Flood Risk Assessment for Decision Making Approach

Science.gov (United States)

Azizat, Nazirah; Omar, Wan-Mohd-Sabki Wan

2018-03-01

Heavy rainfall, adversely impacting inundation areas, depends on the magnitude of the flood. Significantly, location of settlements, infrastructure and facilities in floodplains result in many regions facing flooding risks. A problem faced by the decision maker in an assessment of flood vulnerability and evaluation of adaptation measures is recurrent flooding in the same areas. Identification of recurrent flooding areas and frequency of floods should be priorities for flood risk management. However, spatial and temporal variability become major factors of uncertainty in flood risk management. Therefore, dynamic and spatial characteristics of these changes in flood impact assessment are important in making decisions about the future of infrastructure development and community life. System dynamics (SD) simulation and hydrodynamic modelling are presented as tools for modelling the dynamic characteristics of flood risk and spatial variability. This paper discusses the integration between spatial and temporal information that is required by the decision maker for the identification of multi-criteria decision problems involving multiple stakeholders.

Patient caries risk assessment

DEFF Research Database (Denmark)

Twetman, Svante; Fontana, Margherita

2009-01-01

Risk assessment is an essential component in the decision-making process for the correct prevention and management of dental caries. Multiple risk factors and indicators have been proposed as targets in the assessment of risk of future disease, varying sometimes based on the age group at which...... they are targeted. Multiple reviews and systematic reviews are available in the literature on this topic. This chapter focusses primarily on results of reviews based on longitudinal studies required to establish the accuracy of caries risk assessment. These findings demonstrate that there is a strong body...... of evidence to support that caries experience is still, unfortunately, the single best predictor for future caries development. In young children, prediction models which include a variety of risk factors seem to increase the accuracy of the prediction, while the usefulness of additional risk factors...

Risk Assessment of Geologic Formation Sequestration in The Rocky Mountain Region, USA

Energy Technology Data Exchange (ETDEWEB)

Lee, Si-Yong; McPherson, Brian

2013-08-01

The purpose of this report is to describe the outcome of a targeted risk assessment of a candidate geologic sequestration site in the Rocky Mountain region of the USA. Specifically, a major goal of the probabilistic risk assessment was to quantify the possible spatiotemporal responses for Area of Review (AoR) and injection-induced pressure buildup associated with carbon dioxide (CO₂) injection into the subsurface. Because of the computational expense of a conventional Monte Carlo approach, especially given the likely uncertainties in model parameters, we applied a response surface method for probabilistic risk assessment of geologic CO₂ storage in the Permo-Penn Weber formation at a potential CCS site in Craig, Colorado. A site-specific aquifer model was built for the numerical simulation based on a regional geologic model.

Building better environmental risk assessments

Directory of Open Access Journals (Sweden)

Raymond eLayton

2015-08-01

Full Text Available Risk assessment is a reasoned, structured approach to address uncertainty based on scientific and technical evidence. It forms the foundation for regulatory decision making, which is bound by legislative and policy requirements, as well as the need for making timely decisions using available resources. In order to be most useful, environmental risk assessments (ERA for genetically modified (GM crops should provide consistent, reliable, and transparent results across all types of GM crops, traits, and environments. The assessments must also separate essential information from scientific or agronomic data of marginal relevance or value for evaluating risk and complete the assessment in a timely fashion. Challenges in conducting ERAs differ across regulatory systems – examples are presented from Canada, Malaysia, and Argentina. One challenge faced across the globe is the conduct of risk assessments with limited resources. This challenge can be overcome by clarifying risk concepts, placing greater emphasis on data critical to assess environmental risk (for example, phenotypic and plant performance data rather than molecular data, and adapting advances in risk analysis from other relevant disciplines.

Building Better Environmental Risk Assessments

Science.gov (United States)

Layton, Raymond; Smith, Joe; Macdonald, Phil; Letchumanan, Ramatha; Keese, Paul; Lema, Martin

2015-01-01

Risk assessment is a reasoned, structured approach to address uncertainty based on scientific and technical evidence. It forms the foundation for regulatory decision-making, which is bound by legislative and policy requirements, as well as the need for making timely decisions using available resources. In order to be most useful, environmental risk assessments (ERAs) for genetically modified (GM) crops should provide consistent, reliable, and transparent results across all types of GM crops, traits, and environments. The assessments must also separate essential information from scientific or agronomic data of marginal relevance or value for evaluating risk and complete the assessment in a timely fashion. Challenges in conducting ERAs differ across regulatory systems – examples are presented from Canada, Malaysia, and Argentina. One challenge faced across the globe is the conduct of risk assessments with limited resources. This challenge can be overcome by clarifying risk concepts, placing greater emphasis on data critical to assess environmental risk (for example, phenotypic and plant performance data rather than molecular data), and adapting advances in risk analysis from other relevant disciplines. PMID:26301217

Building Better Environmental Risk Assessments.

Science.gov (United States)

Layton, Raymond; Smith, Joe; Macdonald, Phil; Letchumanan, Ramatha; Keese, Paul; Lema, Martin

2015-01-01

Risk assessment is a reasoned, structured approach to address uncertainty based on scientific and technical evidence. It forms the foundation for regulatory decision-making, which is bound by legislative and policy requirements, as well as the need for making timely decisions using available resources. In order to be most useful, environmental risk assessments (ERAs) for genetically modified (GM) crops should provide consistent, reliable, and transparent results across all types of GM crops, traits, and environments. The assessments must also separate essential information from scientific or agronomic data of marginal relevance or value for evaluating risk and complete the assessment in a timely fashion. Challenges in conducting ERAs differ across regulatory systems - examples are presented from Canada, Malaysia, and Argentina. One challenge faced across the globe is the conduct of risk assessments with limited resources. This challenge can be overcome by clarifying risk concepts, placing greater emphasis on data critical to assess environmental risk (for example, phenotypic and plant performance data rather than molecular data), and adapting advances in risk analysis from other relevant disciplines.

Risk Assessment Stability: A Revalidation Study of the Arizona Risk/Needs Assessment Instrument

Science.gov (United States)

Schwalbe, Craig S.

2009-01-01

The actuarial method is the gold standard for risk assessment in child welfare, juvenile justice, and criminal justice. It produces risk classifications that are highly predictive and that may be robust to sampling error. This article reports a revalidation study of the Arizona Risk/Needs Assessment instrument, an actuarial instrument for juvenile…

Uncertainties in risk assessment and decision making

International Nuclear Information System (INIS)

Starzec, Peter; Purucker, Tom; Stewart, Robert

2008-02-01

confidence interval under different assumptions regarding the data structure. The results stress the importance to invoke statistical methods and also illustrate how the choice of a wrong methodology may affect the quality of risk assessment and foundations for decision making. The uncertainty in assessing the volume of contaminated soil was shown to be dependant only to a low extent on the interpolation technique used for the specific case study analyzed. It is, however, expected that the uncertainty may increase significantly, if more restrictive risk criteria (lower guideline value) are applied. Despite a possible low uncertainty in assessing the contaminated soil volume, the uncertainty in its localization can be substantial. Based on the demo example presented, it comes out that the risk-based input for decision on soil treatment may vary depending on what assumptions were adopted during interpolation process. Uncertainty in an ecological exposure model with regard to the moving pattern of a receptor in relation till spatial distribution of contaminant has been demonstrated by studies on pronghorn (Antilocapra americana). The results from numerical simulations show that a lack in knowledge on the receptor moving routes may bring about substantial uncertainty in exposure assessment. The presented concept is mainly applicable for 'mobile' receptors on relatively large areas. A number of statistical definitions/methods/concepts are presented in the report of which some are not elaborated on in detail, while readers are referred to proper literature. The mail goal with the study has been rather to shed more light on aspects related to uncertainty in risk assessment and to demonstrate potential consequences of wrong approach than to provide readers with formal guideline and recommendations. However, the outcome from the study will hopefully contribute to the further work on novel approaches towards more reliable risk assessments

Risk assessment of flood disaster and forewarning model at different spatial-temporal scales

Science.gov (United States)

Zhao, Jun; Jin, Juliang; Xu, Jinchao; Guo, Qizhong; Hang, Qingfeng; Chen, Yaqian

2018-05-01

Aiming at reducing losses from flood disaster, risk assessment of flood disaster and forewarning model is studied. The model is built upon risk indices in flood disaster system, proceeding from the whole structure and its parts at different spatial-temporal scales. In this study, on the one hand, it mainly establishes the long-term forewarning model for the surface area with three levels of prediction, evaluation, and forewarning. The method of structure-adaptive back-propagation neural network on peak identification is used to simulate indices in prediction sub-model. Set pair analysis is employed to calculate the connection degrees of a single index, comprehensive index, and systematic risk through the multivariate connection number, and the comprehensive assessment is made by assessment matrixes in evaluation sub-model. The comparison judging method is adopted to divide warning degree of flood disaster on risk assessment comprehensive index with forewarning standards in forewarning sub-model and then the long-term local conditions for proposing planning schemes. On the other hand, it mainly sets up the real-time forewarning model for the spot, which introduces the real-time correction technique of Kalman filter based on hydrological model with forewarning index, and then the real-time local conditions for presenting an emergency plan. This study takes Tunxi area, Huangshan City of China, as an example. After risk assessment and forewarning model establishment and application for flood disaster at different spatial-temporal scales between the actual and simulated data from 1989 to 2008, forewarning results show that the development trend for flood disaster risk remains a decline on the whole from 2009 to 2013, despite the rise in 2011. At the macroscopic level, project and non-project measures are advanced, while at the microcosmic level, the time, place, and method are listed. It suggests that the proposed model is feasible with theory and application, thus

RISK MANAGEMENT: AN INTEGRATED APPROACH TO RISK MANAGEMENT AND ASSESSMENT

Directory of Open Access Journals (Sweden)

Szabo Alina

2012-12-01

Full Text Available Purpose: The objective of this paper is to offer an overview over risk management cycle by focusing on prioritization and treatment, in order to ensure an integrated approach to risk management and assessment, and establish the ‘top 8-12’ risks report within the organization. The interface with Internal Audit is ensured by the implementation of the scoring method to prioritize risks collected from previous generated risk report. Methodology/approach: Using evidence from other research in the area and the professional expertise, this article outlines an integrated approach to risk assessment and risk management reporting processes, by separating the risk in two main categories: strategic and operational risks. The focus is on risk prioritization and scoring; the final output will comprise a mix of strategic and operational (‘top 8-12’ risks, which should be used to establish the annual Internal Audit plan. Originality/value: By using an integrated approach to risk assessment and risk management will eliminate the need for a separate Internal Audit risk assessment over prevailing risks. It will reduce the level of risk assessment overlap by different functions (Tax, Treasury, Information System over the same risk categories as a single methodology, is used and will align timings of risk assessment exercises. The risk prioritization by usage of risk and control scoring criteria highlights the combination between financial and non-financial impact criteria allowing risks that do not naturally lend themselves to a financial amount to be also assessed consistently. It is emphasized the usage of score method to prioritize the risks included in the annual audit plan in order to increase accuracy and timelines.

A counterfactual p-value approach for benefit-risk assessment in clinical trials.

Science.gov (United States)

Zeng, Donglin; Chen, Ming-Hui; Ibrahim, Joseph G; Wei, Rachel; Ding, Beiying; Ke, Chunlei; Jiang, Qi

2015-01-01

Clinical trials generally allow various efficacy and safety outcomes to be collected for health interventions. Benefit-risk assessment is an important issue when evaluating a new drug. Currently, there is a lack of standardized and validated benefit-risk assessment approaches in drug development due to various challenges. To quantify benefits and risks, we propose a counterfactual p-value (CP) approach. Our approach considers a spectrum of weights for weighting benefit-risk values and computes the extreme probabilities of observing the weighted benefit-risk value in one treatment group as if patients were treated in the other treatment group. The proposed approach is applicable to single benefit and single risk outcome as well as multiple benefit and risk outcomes assessment. In addition, the prior information in the weight schemes relevant to the importance of outcomes can be incorporated in the approach. The proposed CPs plot is intuitive with a visualized weight pattern. The average area under CP and preferred probability over time are used for overall treatment comparison and a bootstrap approach is applied for statistical inference. We assess the proposed approach using simulated data with multiple efficacy and safety endpoints and compare its performance with a stochastic multi-criteria acceptability analysis approach.

Visual and Auditory Cue Effects on Risk Assessment in a Highway Training Simulation

NARCIS (Netherlands)

Toet, A.; Houtkamp, J.M.; Meulen, van der R.

2013-01-01

We investigated whether manipulation of visual and auditory depth and speed cues can affect a user’s sense of risk for a low-cost nonimmersive virtual environment (VE) representing a highway environment with traffic incidents. The VE is currently used in an examination program to assess procedural

Visual and auditory cue effects on risk assessment in a highway training simulation

NARCIS (Netherlands)

Toet, A.; Houtkamp, J.M.; Meulen, R. van der

2013-01-01

We investigated whether manipulation of visual and auditory depth and speed cues can affect a user’s sense of risk for a low-cost nonimmersive virtual environment (VE) representing a highway environment with traffic incidents. The VE is currently used in an examination program to assess procedural

[Uncertainty analysis of ecological risk assessment caused by heavy-metals deposition from MSWI emission].

Science.gov (United States)

Liao, Zhi-Heng; Sun, Jia-Ren; Wu, Dui; Fan, Shao-Jia; Ren, Ming-Zhong; Lü, Jia-Yang

2014-06-01

The CALPUFF model was applied to simulate the ground-level atmospheric concentrations of Pb and Cd from municipal solid waste incineration (MSWI) plants, and the soil concentration model was used to estimate soil concentration increments after atmospheric deposition based on Monte Carlo simulation, then ecological risk assessment was conducted by the potential ecological risk index method. The results showed that the largest atmospheric concentrations of Pb and Cd were 5.59 x 109-3) microg x m(-3) and 5.57 x 10(-4) microg x m(-3), respectively, while the maxima of soil concentration incremental medium of Pb and Cd were 2.26 mg x kg(-1) and 0.21 mg x kg(-1), respectively; High risk areas were located next to the incinerators, Cd contributed the most to the ecological risk, and Pb was basically free of pollution risk; Higher ecological hazard level was predicted at the most polluted point in urban areas with a 55.30% probability, while in rural areas, the most polluted point was assessed to moderate ecological hazard level with a 72.92% probability. In addition, sensitivity analysis of calculation parameters in the soil concentration model was conducted, which showed the simulated results of urban and rural area were most sensitive to soil mix depth and dry deposition rate, respectively.

Modelling and Simulating of Risk Behaviours in Virtual Environments Based on Multi-Agent and Fuzzy Logic

Directory of Open Access Journals (Sweden)

Linqin Cai

2013-11-01

Full Text Available Due to safety and ethical issues, traditional experimental approaches to modelling underground risk behaviours can be costly, dangerous and even impossible to realize. Based on multi-agent technology, a virtual coalmine platform for risk behaviour simulation is presented to model and simulate the human-machine-environment related risk factors in underground coalmines. To reveal mine workers' risk behaviours, a fuzzy emotional behaviour model is proposed to simulate underground miners' responding behaviours to potential hazardous events based on cognitive appraisal theories and fuzzy logic techniques. The proposed emotion model can generate more believable behaviours for virtual miners according to personalized emotion states, internal motivation needs and behaviour selection thresholds. Finally, typical accident cases of underground hazard spotting and locomotive transport were implemented. The behaviour believability of virtual miners was evaluated with a user assessment method. Experimental results show that the proposed models can create more realistic and reasonable behaviours in virtual coalmine environments, which can improve miners' risk awareness and further train miners' emergent decision-making ability when facing unexpected underground situations.

Risk assessment: 'A consumer's perspective'

International Nuclear Information System (INIS)

Waterhouse, Rachel

1992-01-01

The paper assesses the concept of risk, risk assessment and tolerability of risk from consumer point of view. Review of existing UK and EC directives on certain products and appliances is also covered

Risk assessment: 'A consumer's perspective'

Energy Technology Data Exchange (ETDEWEB)

Waterhouse, Rachel [Consumer' s Association, Health and Safety Commission (United Kingdom)

1992-07-01

The paper assesses the concept of risk, risk assessment and tolerability of risk from consumer point of view. Review of existing UK and EC directives on certain products and appliances is also covered.

A risk-informed approach to the assessment of DHC initiation in pressure tubes

International Nuclear Information System (INIS)

Sahoo, A.K.; Pandey, M.D.

2009-01-01

The delayed hydride cracking (DHC) of pressure tubes is a serious form of degradation in the reactor core. Flaws in pressure tubes generated by fretting or any other mechanism are potential stress raisers that could become sites of DHC initiation under right circumstances. CSA standard N285.8 recommends deterministic and probabilistic procedures for the assessment of potential for DHC initiation from planar flaws. The deterministic method is simple, but it lacks a risk-informed basis for the assessment. A full probabilistic method based on simulations is tedious to implement. This paper presents an innovative, semi-probabilistic method that bridges the gap between a simple deterministic analysis and complex simulations. In the proposed method, the deterministic assessment criterion of CSA N285.8 standard is calibrated to specified target probabilities of DHC initiation using the concept of partial factors. The main advantage of the proposed approach is that it provides a practical, risk-informed basis for DHC initiation assessment while retaining the simplicity of the deterministic method. (author)

Performing Probabilistic Risk Assessment Through RAVEN

Energy Technology Data Exchange (ETDEWEB)

A. Alfonsi; C. Rabiti; D. Mandelli; J. Cogliati; R. Kinoshita

2013-06-01

The Reactor Analysis and Virtual control ENviroment (RAVEN) code is a software tool that acts as the control logic driver and post-processing engine for the newly developed Thermal-Hydraulic code RELAP-7. RAVEN is now a multi-purpose Probabilistic Risk Assessment (PRA) software framework that allows dispatching different functionalities: Derive and actuate the control logic required to simulate the plant control system and operator actions (guided procedures), allowing on-line monitoring/controlling in the Phase Space Perform both Monte-Carlo sampling of random distributed events and Dynamic Event Tree based analysis Facilitate the input/output handling through a Graphical User Interface (GUI) and a post-processing data mining module

Tutorial: Parallel Computing of Simulation Models for Risk Analysis.

Science.gov (United States)

Reilly, Allison C; Staid, Andrea; Gao, Michael; Guikema, Seth D

2016-10-01

Simulation models are widely used in risk analysis to study the effects of uncertainties on outcomes of interest in complex problems. Often, these models are computationally complex and time consuming to run. This latter point may be at odds with time-sensitive evaluations or may limit the number of parameters that are considered. In this article, we give an introductory tutorial focused on parallelizing simulation code to better leverage modern computing hardware, enabling risk analysts to better utilize simulation-based methods for quantifying uncertainty in practice. This article is aimed primarily at risk analysts who use simulation methods but do not yet utilize parallelization to decrease the computational burden of these models. The discussion is focused on conceptual aspects of embarrassingly parallel computer code and software considerations. Two complementary examples are shown using the languages MATLAB and R. A brief discussion of hardware considerations is located in the Appendix. © 2016 Society for Risk Analysis.

Simulation-based summative assessments in surgery.

Science.gov (United States)

Szasz, Peter; Grantcharov, Teodor P; Sweet, Robert M; Korndorffer, James R; Pedowitz, Robert A; Roberts, Patricia L; Sachdeva, Ajit K

2016-09-01

The American College of Surgeons-Accredited Education Institutes (ACS-AEI) Consortium aims to enhance patient safety and advance surgical education through the use of cutting-edge simulation-based training and assessment methods. The annual ACS-AEI Consortium meeting provides a forum to discuss the latest simulation-based training and assessment methods and includes special panel presentations on key topics. During the 8th annual Consortium, there was a panel presentation on simulation-based summative assessments, during which experiences from across surgical disciplines were presented. The formal presentations were followed by a robust discussion between the conference attendees and the panelists. This report summarizes the panelists' presentations and their ensuing discussion with attendees. The focus of this report is on the basis for and advances in simulation-based summative assessments, the current practices employed across various surgical disciplines, and future directions that may be pursued by the ACS-AEI Consortium. Copyright © 2016 Elsevier Inc. All rights reserved.

Using risk assessment in periodontics.

Science.gov (United States)

Woodman, Alan J

2014-08-01

Risk assessment has become a regular feature in both dental practice and society as a whole, and principles used to assess risk in society are similar to those used in a clinical setting. Although the concept of risk assessment as a prognostic indicator for periodontal disease incidence and activity is well established in the management of periodontitis, the use of risk assessment to manage the practical treatment of periodontitis and its sequelae appears to have less foundation. A simple system of initial risk assessment - building on the use of the Basic Periodontal Examination (BPE), clinical, medical and social factors - is described, linked to protocols for delivering care suited to general dental practice and stressing the role of long-term supportive care. The risks of not treating the patient are considered, together with the possible causes of failure, and the problems of successful treatment are illustrated by the practical management of post-treatment recession.

A total risk assessment methodology for security assessment

International Nuclear Information System (INIS)

Auilar, Richard; Pless, Daniel J.; Kaplan, Paul Garry; Silva, Consuelo Juanita; Rhea, Ronald Edward; Wyss, Gregory Dane; Conrad, Stephen Hamilton

2009-01-01

Sandia National Laboratories performed a two-year Laboratory Directed Research and Development project to develop a new collaborative risk assessment method to enable decision makers to fully consider the interrelationships between threat, vulnerability, and consequence. A five-step Total Risk Assessment Methodology was developed to enable interdisciplinary collaborative risk assessment by experts from these disciplines. The objective of this process is promote effective risk management by enabling analysts to identify scenarios that are simultaneously achievable by an adversary, desirable to the adversary, and of concern to the system owner or to society. The basic steps are risk identification, collaborative scenario refinement and evaluation, scenario cohort identification and risk ranking, threat chain mitigation analysis, and residual risk assessment. The method is highly iterative, especially with regard to scenario refinement and evaluation. The Total Risk Assessment Methodology includes objective consideration of relative attack likelihood instead of subjective expert judgment. The 'probability of attack' is not computed, but the relative likelihood for each scenario is assessed through identifying and analyzing scenario cohort groups, which are groups of scenarios with comparable qualities to the scenario being analyzed at both this and other targets. Scenarios for the target under consideration and other targets are placed into cohort groups under an established ranking process that reflects the following three factors: known targeting, achievable consequences, and the resources required for an adversary to have a high likelihood of success. The development of these target cohort groups implements, mathematically, the idea that adversaries are actively choosing among possible attack scenarios and avoiding scenarios that would be significantly suboptimal to their objectives. An adversary who can choose among only a few comparable targets and scenarios (a

Uncertainty characterization approaches for risk assessment of DBPs in drinking water: a review.

Science.gov (United States)

Chowdhury, Shakhawat; Champagne, Pascale; McLellan, P James

2009-04-01

The management of risk from disinfection by-products (DBPs) in drinking water has become a critical issue over the last three decades. The areas of concern for risk management studies include (i) human health risk from DBPs, (ii) disinfection performance, (iii) technical feasibility (maintenance, management and operation) of treatment and disinfection approaches, and (iv) cost. Human health risk assessment is typically considered to be the most important phase of the risk-based decision-making or risk management studies. The factors associated with health risk assessment and other attributes are generally prone to considerable uncertainty. Probabilistic and non-probabilistic approaches have both been employed to characterize uncertainties associated with risk assessment. The probabilistic approaches include sampling-based methods (typically Monte Carlo simulation and stratified sampling) and asymptotic (approximate) reliability analysis (first- and second-order reliability methods). Non-probabilistic approaches include interval analysis, fuzzy set theory and possibility theory. However, it is generally accepted that no single method is suitable for the entire spectrum of problems encountered in uncertainty analyses for risk assessment. Each method has its own set of advantages and limitations. In this paper, the feasibility and limitations of different uncertainty analysis approaches are outlined for risk management studies of drinking water supply systems. The findings assist in the selection of suitable approaches for uncertainty analysis in risk management studies associated with DBPs and human health risk.

Simulation-based assessment for construction helmets.

Science.gov (United States)

Long, James; Yang, James; Lei, Zhipeng; Liang, Daan

2015-01-01

In recent years, there has been a concerted effort for greater job safety in all industries. Personnel protective equipment (PPE) has been developed to help mitigate the risk of injury to humans that might be exposed to hazardous situations. The human head is the most vulnerable to impact as a moderate magnitude can cause serious injury or death. That is why industries have required the use of an industrial hard hat or helmet. There have only been a few articles published to date that are focused on the risk of head injury when wearing an industrial helmet. A full understanding of the effectiveness of construction helmets on reducing injury is lacking. This paper presents a simulation-based method to determine the threshold at which a human will sustain injury when wearing a construction helmet and assesses the risk of injury for wearers of construction helmets or hard hats. Advanced finite element, or FE, models were developed to study the impact on construction helmets. The FE model consists of two parts: the helmet and the human models. The human model consists of a brain, enclosed by a skull and an outer layer of skin. The level and probability of injury to the head was determined using both the head injury criterion (HIC) and tolerance limits set by Deck and Willinger. The HIC has been widely used to assess the likelihood of head injury in vehicles. The tolerance levels proposed by Deck and Willinger are more suited for finite element models but lack wide-scale validation. Different cases of impact were studied using LSTC's LS-DYNA.

Vehicle response-based track geometry assessment using multi-body simulation

Science.gov (United States)

Kraft, Sönke; Causse, Julien; Coudert, Frédéric

2018-02-01

The assessment of the geometry of railway tracks is an indispensable requirement for safe rail traffic. Defects which represent a risk for the safety of the train have to be identified and the necessary measures taken. According to current standards, amplitude thresholds are applied to the track geometry parameters measured by recording cars. This geometry-based assessment has proved its value but suffers from the low correlation between the geometry parameters and the vehicle reactions. Experience shows that some defects leading to critical vehicle reactions are underestimated by this approach. The use of vehicle responses in the track geometry assessment process allows identifying critical defects and improving the maintenance operations. This work presents a vehicle response-based assessment method using multi-body simulation. The choice of the relevant operation conditions and the estimation of the simulation uncertainty are outlined. The defects are identified from exceedances of track geometry and vehicle response parameters. They are then classified using clustering methods and the correlation with vehicle response is analysed. The use of vehicle responses allows the detection of critical defects which are not identified from geometry parameters.

Supporting Risk Assessment: Accounting for Indirect Risk to Ecosystem Components.

Directory of Open Access Journals (Sweden)

Cathryn Clarke Murray

Full Text Available The multi-scalar complexity of social-ecological systems makes it challenging to quantify impacts from human activities on ecosystems, inspiring risk-based approaches to assessments of potential effects of human activities on valued ecosystem components. Risk assessments do not commonly include the risk from indirect effects as mediated via habitat and prey. In this case study from British Columbia, Canada, we illustrate how such "indirect risks" can be incorporated into risk assessments for seventeen ecosystem components. We ask whether (i the addition of indirect risk changes the at-risk ranking of the seventeen ecosystem components and if (ii risk scores correlate with trophic prey and habitat linkages in the food web. Even with conservative assumptions about the transfer of impacts or risks from prey species and habitats, the addition of indirect risks in the cumulative risk score changes the ranking of priorities for management. In particular, resident orca, Steller sea lion, and Pacific herring all increase in relative risk, more closely aligning these species with their "at-risk status" designations. Risk assessments are not a replacement for impact assessments, but-by considering the potential for indirect risks as we demonstrate here-they offer a crucial complementary perspective for the management of ecosystems and the organisms within.

Probabilistic and deterministic risk assessment for extreme objects and ecologically hazardous systems

Directory of Open Access Journals (Sweden)

Yu. V. Veryuzhsky

2003-06-01

Full Text Available The paper include mostly the results of works of the Research Institute for Mechanics of Quickproceeding Processes united in a general research direction - creation of the methodology for risk assessment and risk management for ecologically hazardous systems, consisting of the set of different technological analyzed objects. The elements of system can be characterized by high level of radiation, toxic, explosion, fire and other hazards. The probalistic and deterministic approach for risk assessment, based on mathematical methods of system analysis, non-liner dynamics and computer simulation, has been developed. Branching in problem definition, as well as diversity of factor and criteria for determination of system status, is also taken into account. The risks caused by both objective and subjective factors (including human factor are examined. In many performed studies, the leading structural element, dominating in determination of the system safety, is the structural part of an object. The methodology is implemented for the safety analysis (risk assessment for Chernobyl NPP Shelton Object and other industrial buildings

24 CFR 35.315 - Risk assessment.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Risk assessment. 35.315 Section 35... Provided by a Federal Agency Other Than HUD § 35.315 Risk assessment. Each owner shall complete a risk assessment in accordance with 40 CFR 745.227(d). Each risk assessment shall be completed in accordance with...

Exploring the uncertainties in cancer risk assessment using the integrated probabilistic risk assessment (IPRA) approach.

Science.gov (United States)

Slob, Wout; Bakker, Martine I; Biesebeek, Jan Dirk Te; Bokkers, Bas G H

2014-08-01

Current methods for cancer risk assessment result in single values, without any quantitative information on the uncertainties in these values. Therefore, single risk values could easily be overinterpreted. In this study, we discuss a full probabilistic cancer risk assessment approach in which all the generally recognized uncertainties in both exposure and hazard assessment are quantitatively characterized and probabilistically evaluated, resulting in a confidence interval for the final risk estimate. The methodology is applied to three example chemicals (aflatoxin, N-nitrosodimethylamine, and methyleugenol). These examples illustrate that the uncertainty in a cancer risk estimate may be huge, making single value estimates of cancer risk meaningless. Further, a risk based on linear extrapolation tends to be lower than the upper 95% confidence limit of a probabilistic risk estimate, and in that sense it is not conservative. Our conceptual analysis showed that there are two possible basic approaches for cancer risk assessment, depending on the interpretation of the dose-incidence data measured in animals. However, it remains unclear which of the two interpretations is the more adequate one, adding an additional uncertainty to the already huge confidence intervals for cancer risk estimates. © 2014 Society for Risk Analysis.

Supporting Risk Assessment: Accounting for Indirect Risk to Ecosystem Components

Science.gov (United States)

Mach, Megan E.; Martone, Rebecca G.; Singh, Gerald G.; O, Miriam; Chan, Kai M. A.

2016-01-01

The multi-scalar complexity of social-ecological systems makes it challenging to quantify impacts from human activities on ecosystems, inspiring risk-based approaches to assessments of potential effects of human activities on valued ecosystem components. Risk assessments do not commonly include the risk from indirect effects as mediated via habitat and prey. In this case study from British Columbia, Canada, we illustrate how such “indirect risks” can be incorporated into risk assessments for seventeen ecosystem components. We ask whether (i) the addition of indirect risk changes the at-risk ranking of the seventeen ecosystem components and if (ii) risk scores correlate with trophic prey and habitat linkages in the food web. Even with conservative assumptions about the transfer of impacts or risks from prey species and habitats, the addition of indirect risks in the cumulative risk score changes the ranking of priorities for management. In particular, resident orca, Steller sea lion, and Pacific herring all increase in relative risk, more closely aligning these species with their “at-risk status” designations. Risk assessments are not a replacement for impact assessments, but—by considering the potential for indirect risks as we demonstrate here—they offer a crucial complementary perspective for the management of ecosystems and the organisms within. PMID:27632287

Avalanche risk assessment in Russia

Science.gov (United States)

Komarov, Anton; Seliverstov, Yury; Sokratov, Sergey; Glazovskaya, Tatiana; Turchaniniva, Alla

2017-04-01

The avalanche prone area covers about 3 million square kilometers or 18% of total area of Russia and pose a significant problem in most mountain regions of the country. The constant growth of economic activity, especially in the North Caucasus region and therefore the increased avalanche hazard lead to the demand of the large-scale avalanche risk assessment methods development. Such methods are needed for the determination of appropriate avalanche protection measures as well as for economic assessments during all stages of spatial planning of the territory. The requirement of natural hazard risk assessments is determined by the Federal Law of Russian Federation. However, Russian Guidelines (SP 11-103-97; SP 47.13330.2012) are not clearly presented concerning avalanche risk assessment calculations. A great size of Russia territory, vast diversity of natural conditions and large variations in type and level of economic development of different regions cause significant variations in avalanche risk values. At the first stage of research the small scale avalanche risk assessment was performed in order to identify the most common patterns of risk situations and to calculate full social risk and individual risk. The full social avalanche risk for the territory of country was estimated at 91 victims. The area of territory with individual risk values lesser then 1×10(-6) covers more than 92 % of mountain areas of the country. Within these territories the safety of population can be achieved mainly by organizational activities. Approximately 7% of mountain areas have 1×10(-6) - 1×10(-4) individual risk values and require specific mitigation measures to protect people and infrastructure. Territories with individual risk values 1×10(-4) and above covers about 0,1 % of the territory and include the most severe and hazardous mountain areas. The whole specter of mitigation measures is required in order to minimize risk. The future development of such areas is not recommended

Risk assessment in international operations

International Nuclear Information System (INIS)

Stricklin, Daniela L.

2008-01-01

During international peace-keeping missions, a diverse number of non-battle hazards may be encountered, which range from heavily polluted areas, endemic disease, toxic industrial materials, local violence, traffic, and even psychological factors. Hence, elevated risk levels from a variety of sources are encountered during deployments. With the emphasis within the Swedish military moving from national defense towards prioritization of international missions in atypical environments, the risk of health consequences, including long term health effects, has received greater consideration. The Swedish military is interested in designing an optimal approach for assessment of health threats during deployments. The Medical Intelligence group at FOI CBRN Security and Defence in Umea has, on request from and in collaboration with the Swedish Armed Forces, reviewed a variety of international health threat and risk assessment models for military operations. Application of risk assessment methods used in different phases of military operations will be reviewed. An overview of different international approaches used in operational risk management (ORM) will be presented as well as a discussion of the specific needs and constraints for health risk assessment in military operations. This work highlights the specific challenges of risk assessment that are unique to the deployment setting such as the assessment of exposures to a variety of diverse hazards concurrently

Implications of probabilistic risk assessment

International Nuclear Information System (INIS)

Cullingford, M.C.; Shah, S.M.; Gittus, J.H.

1987-01-01

Probabilistic risk assessment (PRA) is an analytical process that quantifies the likelihoods, consequences and associated uncertainties of the potential outcomes of postulated events. Starting with planned or normal operation, probabilistic risk assessment covers a wide range of potential accidents and considers the whole plant and the interactions of systems and human actions. Probabilistic risk assessment can be applied in safety decisions in design, licensing and operation of industrial facilities, particularly nuclear power plants. The proceedings include a review of PRA procedures, methods and technical issues in treating uncertainties, operating and licensing issues and future trends. Risk assessment for specific reactor types or components and specific risks (eg aircraft crashing onto a reactor) are used to illustrate the points raised. All 52 articles are indexed separately. (U.K.)

Uncertainties in risk assessment at USDOE facilities

Energy Technology Data Exchange (ETDEWEB)

Hamilton, L.D.; Holtzman, S.; Meinhold, A.F.; Morris, S.C.; Rowe, M.D.

1994-01-01

The United States Department of Energy (USDOE) has embarked on an ambitious program to remediate environmental contamination at its facilities. Decisions concerning cleanup goals, choices among cleanup technologies, and funding prioritization should be largely risk-based. Risk assessments will be used more extensively by the USDOE in the future. USDOE needs to develop and refine risk assessment methods and fund research to reduce major sources of uncertainty in risk assessments at USDOE facilities. The terms{open_quote} risk assessment{close_quote} and{open_quote} risk management{close_quote} are frequently confused. The National Research Council (1983) and the United States Environmental Protection Agency (USEPA, 1991a) described risk assessment as a scientific process that contributes to risk management. Risk assessment is the process of collecting, analyzing and integrating data and information to identify hazards, assess exposures and dose responses, and characterize risks. Risk characterization must include a clear presentation of {open_quotes}... the most significant data and uncertainties...{close_quotes} in an assessment. Significant data and uncertainties are {open_quotes}...those that define and explain the main risk conclusions{close_quotes}. Risk management integrates risk assessment information with other considerations, such as risk perceptions, socioeconomic and political factors, and statutes, to make and justify decisions. Risk assessments, as scientific processes, should be made independently of the other aspects of risk management (USEPA, 1991a), but current methods for assessing health risks are based on conservative regulatory principles, causing unnecessary public concern and misallocation of funds for remediation.

Uncertainties in risk assessment at USDOE facilities

International Nuclear Information System (INIS)

Hamilton, L.D.; Holtzman, S.; Meinhold, A.F.; Morris, S.C.; Rowe, M.D.

1994-01-01

The United States Department of Energy (USDOE) has embarked on an ambitious program to remediate environmental contamination at its facilities. Decisions concerning cleanup goals, choices among cleanup technologies, and funding prioritization should be largely risk-based. Risk assessments will be used more extensively by the USDOE in the future. USDOE needs to develop and refine risk assessment methods and fund research to reduce major sources of uncertainty in risk assessments at USDOE facilities. The terms open-quote risk assessment close-quote and open-quote risk management close-quote are frequently confused. The National Research Council (1983) and the United States Environmental Protection Agency (USEPA, 1991a) described risk assessment as a scientific process that contributes to risk management. Risk assessment is the process of collecting, analyzing and integrating data and information to identify hazards, assess exposures and dose responses, and characterize risks. Risk characterization must include a clear presentation of open-quotes... the most significant data and uncertainties...close quotes in an assessment. Significant data and uncertainties are open-quotes...those that define and explain the main risk conclusionsclose quotes. Risk management integrates risk assessment information with other considerations, such as risk perceptions, socioeconomic and political factors, and statutes, to make and justify decisions. Risk assessments, as scientific processes, should be made independently of the other aspects of risk management (USEPA, 1991a), but current methods for assessing health risks are based on conservative regulatory principles, causing unnecessary public concern and misallocation of funds for remediation

County-Level Climate Uncertainty for Risk Assessments: Volume 1.

Energy Technology Data Exchange (ETDEWEB)

Backus, George A.; Lowry, Thomas Stephen; Jones, Shannon M; Walker, La Tonya Nicole; Roberts, Barry L; Malczynski, Leonard A.

2017-06-01

This report uses the CMIP5 series of climate model simulations to produce country- level uncertainty distributions for use in socioeconomic risk assessments of climate change impacts. It provides appropriate probability distributions, by month, for 169 countries and autonomous-areas on temperature, precipitation, maximum temperature, maximum wind speed, humidity, runoff, soil moisture and evaporation for the historical period (1976-2005), and for decadal time periods to 2100. It also provides historical and future distributions for the Arctic region on ice concentration, ice thickness, age of ice, and ice ridging in 15-degree longitude arc segments from the Arctic Circle to 80 degrees latitude, plus two polar semicircular regions from 80 to 90 degrees latitude. The uncertainty is meant to describe the lack of knowledge rather than imprecision in the physical simulation because the emphasis is on unfalsified risk and its use to determine potential socioeconomic impacts. The full report is contained in 27 volumes.

Uncertainty assessment of urban pluvial flood risk in a context of climate change adaptation decision making

DEFF Research Database (Denmark)

Arnbjerg-Nielsen, Karsten; Zhou, Qianqian

2014-01-01

uncertainty analysis, which can assess and quantify the overall uncertainty in relation to climate change adaptation to urban flash floods. The analysis is based on an uncertainty cascade that by means of Monte Carlo simulations of flood risk assessments incorporates climate change impacts as a key driver......There has been a significant increase in climatic extremes in many regions. In Central and Northern Europe, this has led to more frequent and more severe floods. Along with improved flood modelling technologies this has enabled development of economic assessment of climate change adaptation...... to increasing urban flood risk. Assessment of adaptation strategies often requires a comprehensive risk-based economic analysis of current risk, drivers of change of risk over time, and measures to reduce the risk. However, such studies are often associated with large uncertainties. The uncertainties arise from...

Advanced Test Reactor outage risk assessment

International Nuclear Information System (INIS)

Thatcher, T.A.; Atkinson, S.A.

1997-01-01

Beginning in 1997, risk assessment was performed for each Advanced Test Reactor (ATR) outage aiding the coordination of plant configuration and work activities (maintenance, construction projects, etc.) to minimize the risk of reactor fuel damage and to improve defense-in-depth. The risk assessment activities move beyond simply meeting Technical Safety Requirements to increase the awareness of risk sensitive configurations, to focus increased attention on the higher risk activities, and to seek cost-effective design or operational changes that reduce risk. A detailed probabilistic risk assessment (PRA) had been performed to assess the risk of fuel damage during shutdown operations including heavy load handling. This resulted in several design changes to improve safety; however, evaluation of individual outages had not been performed previously and many risk insights were not being utilized in outage planning. The shutdown PRA provided the necessary framework for assessing relative and absolute risk levels and assessing defense-in-depth. Guidelines were written identifying combinations of equipment outages to avoid. Screening criteria were developed for the selection of work activities to receive review. Tabulation of inherent and work-related initiating events and their relative risk level versus plant mode has aided identification of the risk level the scheduled work involves. Preoutage reviews are conducted and post-outage risk assessment is documented to summarize the positive and negative aspects of the outage with regard to risk. The risk for the outage is compared to the risk level that would result from optimal scheduling of the work to be performed and to baseline or average past performance

An example of population-level risk assessments for small mammals using individual-based population models.

Science.gov (United States)

Schmitt, Walter; Auteri, Domenica; Bastiansen, Finn; Ebeling, Markus; Liu, Chun; Luttik, Robert; Mastitsky, Sergey; Nacci, Diane; Topping, Chris; Wang, Magnus

2016-01-01

This article presents a case study demonstrating the application of 3 individual-based, spatially explicit population models (IBMs, also known as agent-based models) in ecological risk assessments to predict long-term effects of a pesticide to populations of small mammals. The 3 IBMs each used a hypothetical fungicide (FungicideX) in different scenarios: spraying in cereals (common vole, Microtus arvalis), spraying in orchards (field vole, Microtus agrestis), and cereal seed treatment (wood mouse, Apodemus sylvaticus). Each scenario used existing model landscapes, which differed greatly in size and structural complexity. The toxicological profile of FungicideX was defined so that the deterministic long-term first tier risk assessment would result in high risk to small mammals, thus providing the opportunity to use the IBMs for risk assessment refinement (i.e., higher tier risk assessment). Despite differing internal model design and scenarios, results indicated in all 3 cases low population sensitivity unless FungicideX was applied at very high (×10) rates. Recovery from local population impacts was generally fast. Only when patch extinctions occured in simulations of intentionally high acute toxic effects, recovery periods, then determined by recolonization, were of any concern. Conclusions include recommendations for the most important input considerations, including the selection of exposure levels, duration of simulations, statistically robust number of replicates, and endpoints to report. However, further investigation and agreement are needed to develop recommendations for landscape attributes such as size, structure, and crop rotation to define appropriate regulatory risk assessment scenarios. Overall, the application of IBMs provides multiple advantages to higher tier ecological risk assessments for small mammals, including consistent and transparent direct links to specific protection goals, and the consideration of more realistic scenarios. © 2015 SETAC.

GAR Global Risk Assessment

Science.gov (United States)

Maskrey, Andrew; Safaie, Sahar

2015-04-01

Disaster risk management strategies, policies and actions need to be based on evidence of current disaster loss and risk patterns, past trends and future projections, and underlying risk factors. Faced with competing demands for resources, at any level it is only possible to priorities a range of disaster risk management strategies and investments with adequate understanding of realised losses, current and future risk levels and impacts on economic growth and social wellbeing as well as cost and impact of the strategy. The mapping and understanding of the global risk landscape has been greatly enhanced by the latest iteration of the GAR Global Risk Assessment and the objective of this submission is to present the GAR global risk assessment which contributed to Global Assessment Report (GAR) 2015. This initiative which has been led by UNISDR, was conducted by a consortium of technical institutions from around the world and has covered earthquake, cyclone, riverine flood, and tsunami probabilistic risk for all countries of the world. In addition, the risks associated with volcanic ash in the Asia-Pacific region, drought in various countries in sub-Saharan Africa and climate change in a number of countries have been calculated. The presentation will share thee results as well as the experience including the challenges faced in technical elements as well as the process and recommendations for the future of such endeavour.

Quantitative risk assessment of E. coli in street-vended cassava-based delicacies in the Philippines

Science.gov (United States)

Mesias, I. C. P.

2018-01-01

In the Philippines, rootcrop-based food products are gaining popularity in street food trade. However, a number of street-vended food products in the country are reported to be contaminated with E. coli posing possible risk among consumers. In this study, information on quantitative risk assessment of E. coli in street-vended cassava-based delicacies was generated. The assessment started with the prevalence and concentration of E. coli at post production in packages of the cassava-based delicacies. Combase growth predictor was used to trace the microbial population of E. coli in each step of the food chain. The @Risk software package, version 6 (Palisade USA) was used to run the simulations. Scenarios in the post-production to consumption pathway were simulated. The effect was then assessed in relation to exposure to the defined infective dose. In the worst case scenario, a minimum and most likely concentration of 6.3 and 7.8 log CFU of E. coli per serving respectively were observed. The simulation revealed that lowering the temperature in the chain considerably decreased the E. coli concentration prior to consumption and subsequently decreased the percentage of exposure to the infective dose. Exposure to infective dose however was increased with longer lag time from postproduction to consumption.

Deterministic quantitative risk assessment development

Energy Technology Data Exchange (ETDEWEB)

Dawson, Jane; Colquhoun, Iain [PII Pipeline Solutions Business of GE Oil and Gas, Cramlington Northumberland (United Kingdom)

2009-07-01

Current risk assessment practice in pipeline integrity management is to use a semi-quantitative index-based or model based methodology. This approach has been found to be very flexible and provide useful results for identifying high risk areas and for prioritizing physical integrity assessments. However, as pipeline operators progressively adopt an operating strategy of continual risk reduction with a view to minimizing total expenditures within safety, environmental, and reliability constraints, the need for quantitative assessments of risk levels is becoming evident. Whereas reliability based quantitative risk assessments can be and are routinely carried out on a site-specific basis, they require significant amounts of quantitative data for the results to be meaningful. This need for detailed and reliable data tends to make these methods unwieldy for system-wide risk k assessment applications. This paper describes methods for estimating risk quantitatively through the calibration of semi-quantitative estimates to failure rates for peer pipeline systems. The methods involve the analysis of the failure rate distribution, and techniques for mapping the rate to the distribution of likelihoods available from currently available semi-quantitative programs. By applying point value probabilities to the failure rates, deterministic quantitative risk assessment (QRA) provides greater rigor and objectivity than can usually be achieved through the implementation of semi-quantitative risk assessment results. The method permits a fully quantitative approach or a mixture of QRA and semi-QRA to suit the operator's data availability and quality, and analysis needs. For example, consequence analysis can be quantitative or can address qualitative ranges for consequence categories. Likewise, failure likelihoods can be output as classical probabilities or as expected failure frequencies as required. (author)

Quality assurance study of caries risk assessment performance by clinical faculty members in a school of dentistry.

Science.gov (United States)

Rechmann, Peter; Featherstone, John D B

2014-09-01

The goal of this quality assurance study was to explore the decision making of clinical faculty members at the University of California, San Francisco School of Dentistry predoctoral dental clinic in terms of caries risk level assignment using the caries risk assessment (CRA) as part of the Caries Management by Risk Assessment (CAMBRA) concept. This research was done in part to determine if additional training and calibration were needed for these faculty members. The study tested the reliability and reproducibility of the caries risk levels assigned by different clinical teachers who completed CRA forms for simulated patients. In the first step, five clinical teachers assigned caries risk levels for thirteen simulated patients. Six months later, the same five plus an additional nine faculty members assigned caries risk levels to the same thirteen simulated and nine additional cases. While the intra-examiner reliability with weighted kappa strength of agreement was very high, the inter-examiner agreements with a gold standard were on average only moderate. In total, 20 percent of the presented high caries risk cases were underestimated at caries levels too low, even when obvious caries disease indicators were present. This study suggests that more consistent training and calibration of clinical faculty members as well as students are needed.

Evaluation of thermal risk assessment

International Nuclear Information System (INIS)

Loos, J.J.; Perry, E.S.

1993-01-01

Risk assessment was done in 1983 to estimate the ecological hazard of increasing the generating load and thermal output of an electric generating station. Subsequently, long-term monitoring in the vicinity of the station allowed verification of the predictions made in the risk assessment. This presentation will review the efficacy of early risk assessment methods in producing useful predictions from a resource management point of view. In 1984, the Chalk Point Generating facility of the Potomac Electric Power Company increased it's median generating load by 100%. Prior to this operational change, the Academy of Natural Sciences of Philadelphia synthesized site specific data, model predictions, and results from literature to assess the risk of additional waste heat to the Patuxent River subestuary of Chesapeake Bay. Risk was expressed as the number of days per year that various species of fish and the blue crab would be expected to avoid the discharge vicinity. Accuracy of these predictions is assessed by comparing observed fish and crab distributions and their observed frequencies of avoidance to those predicted. It is concluded that the predictions of this early risk assessment were sufficiently accurate to produce a reliable resource management decision

On risk assessment of energy production

International Nuclear Information System (INIS)

Kunii, Katsuhiko

2005-07-01

Today we cannot ignore the risk of health and/or environment by energy production such as power generation since the risk has been made large enough. In this report an information survey has been done in order to know the outline and points of risk assessment. Based on the information of reports and literature about risk assessment, have been surveyed mainly the external cost assessment of power generation (in which quantification of health and/or environment risk has been done), in addition, risks of disasters, accidents, investments, finance etc. and impacts of those risks on social activities. The remarks obtained by the survey are as follows: 1) Some of external cost assessment of power generation show different results even if the assessment conditions of technology, site, etc. are mostly the same. It is necessary to remark on the information such as basic data, model, background, application limit of assessment considering the reliability. 2) Especially it is considered that the reliability of risk assessment is not enough at present because of the lack of basic data. (author)

Risk assessment of N-nitrosodimethylamine formed endogenously after fish-with-vegetable meals

NARCIS (Netherlands)

Zeilmaker, M.J.; Bakker, M.I.; Schothorst, R.; Slob, W.

2010-01-01

The consumption of fish and nitrate-rich vegetables may lead to the formation of the genotoxic carcinogen N-nitrosodimethylamine (NDMA) in the stomach. To assess human cancer risk associated with this formation, a dynamic in vitro gastrointestinal model was used to simulate NDMA formation in the

Defense Programs Transportation Risk Assessment

International Nuclear Information System (INIS)

Clauss, D.B.

1994-01-01

This paper provides an overview of the methodology used in a probabilistic transportation risk assessment conducted to assess the probabilities and consequences of inadvertent dispersal of radioactive materials arising from severe transportation accidents. The model was developed for the Defense Program Transportation Risk Assessment (DPTRA) study. The analysis incorporates several enhancements relative to previous risk assessments of hazardous materials transportation including newly-developed statistics on the frequencies and severities of tractor semitrailer accidents and detailed route characterization using the 1990 Census data

Risk Factor Assessment Branch (RFAB)

Science.gov (United States)

The Risk Factor Assessment Branch (RFAB) focuses on the development, evaluation, and dissemination of high-quality risk factor metrics, methods, tools, technologies, and resources for use across the cancer research continuum, and the assessment of cancer-related risk factors in the population.

A possibilistic analysis approach for environmental risk assessment of petroleum-contaminated sites

International Nuclear Information System (INIS)

Liu, L.; Huang, G.H.; Fuller, G.A.

1999-01-01

A possibilistic approach for assessing risks associated with petroleum-contaminated sites is provided. The approach is applied to an illustrative case study in order to show its applicability and implementation for decision making in effective site remediation and management. The approach consists of three main parts: (1) the determination of fuzzy steady state contaminant concentrations in a aquifer based on an analytical solute transport model; (2) possibilistic analysis of fuzzy criteria for different risk levels; and (3) environmental risk assessment based on the Euclidian method. Based on results from an illustrative case study, environmental risks at a petroleum-contaminated site can be effectively evaluated using the developed methodology. The risk assessment framework can effectively handle uncertainities presented as fuzzy numbers. The fuzzy nature of water quality and risk level criteria were seen in the related simulation and evaluation models, and the framework is especially useful for situations in which probabilistic information is not available. This use of this approach is new in the area of petroleum waste management under uncertainty, and its results are useful for the related site remediation and management decisions. 36 refs., 1 tab., 4 figs

Risk assessments ensure safer power

Energy Technology Data Exchange (ETDEWEB)

1982-02-19

A growth industry is emerging devoted to the study and comparison of the economic, social and health risks posed by large industrial installations. Electricity generation is one area coming under particularly close scrutiny. Types of risk, ways of assessing risk and the difference between experts' analyses and the public perception of risk are given. An example of improved risk assessment helping to reduce deaths and injuries in coal mining is included.

Risk assessment

DEFF Research Database (Denmark)

Pedersen, Liselotte; Rasmussen, Kirsten; Elsass, Peter

2010-01-01

International research suggests that using formalized risk assessment methods may improve the predictive validity of professionals' predictions of risk of future violence. This study presents data on forensic psychiatric patients discharged from a forensic unit in Denmark in year 2001-2002 (n=107...... and the individual dynamic items strengthen the use of this scheme in clinical practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved) (journal abstract)...

Sudden Cardiac Arrest (SCA) Risk Assessment

Science.gov (United States)

... HRS Find a Specialist Share Twitter Facebook SCA Risk Assessment Sudden Cardiac Arrest (SCA) occurs abruptly and without ... people of all ages and health conditions. Start Risk Assessment The Sudden Cardiac Arrest (SCA) Risk Assessment Tool ...

Integrated climate change risk assessment:

DEFF Research Database (Denmark)

Kaspersen, Per Skougaard; Halsnæs, Kirsten

2017-01-01

Risk assessments of flooding in urban areas during extreme precipitation for use in, for example, decision-making regarding climate adaptation, are surrounded by great uncertainties stemming from climate model projections, methods of downscaling and the assumptions of socioeconomic impact models...... to address the complex linkages between the different kinds of data required in assessing climate adaptation. It emphasizes that the availability of spatially explicit data can reduce the overall uncertainty of the risk assessment and assist in identifying key vulnerable assets. The usefulness...... of such a framework is demonstrated by means of a risk assessment of flooding from extreme precipitation for the city of Odense, Denmark. A sensitivity analysis shows how the presence of particularly important assets, such as cultural and historical heritage, may be addressed in assessing such risks. The output...

Identifying content for simulation-based curricula in urology: a national needs assessment.

Science.gov (United States)

Nayahangan, Leizl Joy; Bølling Hansen, Rikke; Gilboe Lindorff-Larsen, Karen; Paltved, Charlotte; Nielsen, Bjørn Ulrik; Konge, Lars

2017-12-01

Simulation-based training is well recognized in the transforming field of urological surgery; however, integration into the curriculum is often unstructured. Development of simulation-based curricula should follow a stepwise approach starting with a needs assessment. This study aimed to identify technical procedures in urology that should be included in a simulation-based curriculum for residency training. A national needs assessment was performed using the Delphi method involving 56 experts with significant roles in the education of urologists. Round 1 identified technical procedures that newly qualified urologists should perform. Round 2 included a survey using an established needs assessment formula to explore: the frequency of procedures; the number of physicians who should be able to perform the procedure; the risk and/or discomfort to patients when a procedure is performed by an inexperienced physician; and the feasibility of simulation training. Round 3 involved elimination and reranking of procedures according to priority. The response rates for the three Delphi rounds were 70%, 55% and 67%, respectively. The 34 procedures identified in Round 1 were reduced to a final prioritized list of 18 technical procedures for simulation-based training. The five procedures that reached the highest prioritization were cystoscopy, transrectal ultrasound-guided biopsy of the prostate, placement of ureteral stent, insertion of urethral and suprapubic catheter, and transurethral resection of the bladder. The prioritized list of technical procedures in urology that were identified as highly suitable for simulation can be used as an aid in the planning and development of simulation-based training programs.

Online application of a risk management system for risk assessment and monitoring at NPPs

Energy Technology Data Exchange (ETDEWEB)

Yang, Jun, E-mail: youngjun51@hotmail.com [Key Laboratory of Fundamental Science on Nuclear Safety and Simulation Technology, Harbin Engineering University (China); Yang, Ming, E-mail: yangming@hrbeu.edu.cn [Key Laboratory of Fundamental Science on Nuclear Safety and Simulation Technology, Harbin Engineering University (China); Wang, Wenlin, E-mail: wlwang0618@126.com [Key Laboratory of Fundamental Science on Nuclear Safety and Simulation Technology, Harbin Engineering University (China); Li, Fengjun, E-mail: leefengjun@163.com [China Nuclear Power Engineering Co. Ltd (China)

2016-08-15

Highlights: • A generic GO-FLOW modeling structure is proposed for easily Living PSA development and analysis. • Hierarchical and modularized scheme is applied in the development of Living PSA models and database. • A risk management system is developed by GO-FLOW method. • Functional testing is conducted on the risk management system for performance evaluation. • The fast solution time derived from Living PSA application is supportive in plant safety management. - Abstract: The paper presents a risk management system on the basis of Living PSA models which are developed under a proposed generic GO-FLOW modeling method with a hierarchical and modular structure. The design of the risk management system is aiming at assisting plant personnel to manage maintenance plan and system configuration, and conduct system reliability monitoring, risk monitoring and risk management quickly and conveniently through graphical user interfaces without going deep into the details of building, updating and analyzing reliability and risk models. The performance of the proposed risk management system was tested on a full-scale simulator of PWR nuclear power plant and demonstrated that the fast solution time derived from utilization of hierarchical and modularized Living PSA models is strongly supportive for instantaneous risk assessment as well as for daily risk management at NPPs.

Assessment of the Ability of Contemporary Climate Models to Assess Adequately the Risk of Possible Regional Anomalies and Trends

Science.gov (United States)

Mokhov, I. I.

2018-04-01

The results describing the ability of contemporary global and regional climate models not only to assess the risk of general trends of changes but also to predict qualitatively new regional effects are presented. In particular, model simulations predicted spatially inhomogeneous changes in the wind and wave conditions in the Arctic basins, which have been confirmed in recent years. According to satellite and reanalysis data, a qualitative transition to the regime predicted by model simulations occurred about a decade ago.

Risk Assessment of Wastewater Collection Performance Using the Fuzzy Decision-making Approach

Directory of Open Access Journals (Sweden)

Maedeh Asgarian

2015-10-01

Full Text Available Wastewater collection network simulation in normal conditions dose not provide performance assessment in unusual circumstances. In this paper, a model has been developed for risk assessment of wastewater collection systems to manage their performance under natural or man-made critical conditions. In this model, certain criteria were defined, fuzzy MADM techniques were exploited, and a questionnaire was employed to measure such risk parameters as the probability of threats, the severity of their impacts, and the vulnerability of the network components. Based on the calculated magnitude of the risks, the threats and hazards were classified into groups ranging from low-risk to high-risk threats. The approaches adopted to combat the risks were also classified into the following three categories: "to deal with the risk", "risk shifting", and "risk taking". This process was implemented for the wastewater collection system in Shahrak-Gharb District in Tehran as a case study. ‘Introduction of chemical pollutants into the sewers’ and ‘drastic changes in wastewater quality’ were identified as the most threatening crises for the district and the ‘risk reduction strategy’ was proposed for combating the critical conditions in this district.

Assessing Your Weight and Health Risk

Science.gov (United States)

... Health Professional Resources Assessing Your Weight and Health Risk Assessment of weight and health risk involves using ... risk for developing obesity-associated diseases or conditions. Risk Factors for Health Topics Associated With Obesity Along ...

Risk assessment of atmospheric emissions using machine learning

Directory of Open Access Journals (Sweden)

G. Cervone

2008-09-01

Full Text Available Supervised and unsupervised machine learning algorithms are used to perform statistical and logical analysis of several transport and dispersion model runs which simulate emissions from a fixed source under different atmospheric conditions.

First, a clustering algorithm is used to automatically group the results of different transport and dispersion simulations according to specific cloud characteristics. Then, a symbolic classification algorithm is employed to find complex non-linear relationships between the meteorological input conditions and each cluster of clouds. The patterns discovered are provided in the form of probabilistic measures of contamination, thus suitable for result interpretation and dissemination.

The learned patterns can be used for quick assessment of the areas at risk and of the fate of potentially hazardous contaminants released in the atmosphere.

Lava Simulation and Risk Assessment During The July 2001 Etnean Eruption

Science.gov (United States)

Crisci, G. M.; di Gregorio, S.; Rongo, R.; Spataro, W.

SCIARA, a two-dimensional cellular automata model for the simulation of lava flows, has been in the past validated on real cases of Etnean eruptions. Its lastest release, SCIARA-hex1 was applied on the 1991-93 Etnean eruption in validation phase. The simulation results are satisfying within limits to forecast the lava flow path. The pre- sented version isnSt more sophisticated than the previous version, because it does- nSt manage lava layers at different temperatures in the same cell and their distinct outflows, but its speed permitted to generate a large number of scenarios in quickly evolving emergence situation. Moreover, SCIARA-hex1 was applied recently during the Etnean crisis in the summer of 2001, when a new eruption threatened the town of Nicolosi. The emission, that started on July 18th 2001, represented during the cri- sis the main danger for the towns of Nicolosi and Belpasso; it was, in its maximum extension, only four kilometres away from the Nicolosi. The study was done in collab- oration with the Italian National Institute of Geophysics and Vulcanology of Catania. This Sreal timeT application proved that SCIARA is a reliable and flexible tool for & cedil;forecasting lava flow paths and for assessing hazard in the Etnean area, besides being useful for the creation of real scenarios. In SCIARA, lava flows are viewed as a dy- namic system based on local interactions with discrete time and space, where space is represented by hexagonal cells, which specification (state) describes the character- istics (substates) of the corresponding piece of space. The neighbouring of a cell c, specifying the interacting cells, is given by its adjacent cells. The computation of the new values of the substates in the cells gives the evolution of the phenomenon. The distribution of the lava is crucial in the definition of the model: it is based on a proce- dure of minimisation of the differences. Moreover, with respect to previous SCIARA models, spurious symmetries

Monte Carlo simulation of single accident airport risk profile

Science.gov (United States)

1979-01-01

A computer simulation model was developed for estimating the potential economic impacts of a carbon fiber release upon facilities within an 80 kilometer radius of a major airport. The model simulated the possible range of release conditions and the resulting dispersion of the carbon fibers. Each iteration of the model generated a specific release scenario, which would cause a specific amount of dollar loss to the surrounding community. By repeated iterations, a risk profile was generated, showing the probability distribution of losses from one accident. Using accident probability estimates, the risks profile for annual losses was derived. The mechanics are described of the simulation model, the required input data, and the risk profiles generated for the 26 large hub airports.

Risk assessment theory, methods, and applications

CERN Document Server

Rausand, Marvin

2011-01-01

With its balanced coverage of theory and applications along with standards and regulations, Risk Assessment: Theory, Methods, and Applications serves as a comprehensive introduction to the topic. The book serves as a practical guide to current risk analysis and risk assessment, emphasizing the possibility of sudden, major accidents across various areas of practice from machinery and manufacturing processes to nuclear power plants and transportation systems. The author applies a uniform framework to the discussion of each method, setting forth clear objectives and descriptions, while also shedding light on applications, essential resources, and advantages and disadvantages. Following an introduction that provides an overview of risk assessment, the book is organized into two sections that outline key theory, methods, and applications. * Introduction to Risk Assessment defines key concepts and details the steps of a thorough risk assessment along with the necessary quantitative risk measures. Chapters outline...

An introductory guide to uncertainty analysis in environmental and health risk assessment

International Nuclear Information System (INIS)

Hoffman, F.O.; Hammonds, J.S.

1992-10-01

To compensate for the potential for overly conservative estimates of risk using standard US Environmental Protection Agency methods, an uncertainty analysis should be performed as an integral part of each risk assessment. Uncertainty analyses allow one to obtain quantitative results in the form of confidence intervals that will aid in decision making and will provide guidance for the acquisition of additional data. To perform an uncertainty analysis, one must frequently rely on subjective judgment in the absence of data to estimate the range and a probability distribution describing the extent of uncertainty about a true but unknown value for each parameter of interest. This information is formulated from professional judgment based on an extensive review of literature, analysis of the data, and interviews with experts. Various analytical and numerical techniques are available to allow statistical propagation of the uncertainty in the model parameters to a statement of uncertainty in the risk to a potentially exposed individual. Although analytical methods may be straightforward for relatively simple models, they rapidly become complicated for more involved risk assessments. Because of the tedious efforts required to mathematically derive analytical approaches to propagate uncertainty in complicated risk assessments, numerical methods such as Monte Carlo simulation should be employed. The primary objective of this report is to provide an introductory guide for performing uncertainty analysis in risk assessments being performed for Superfund sites

The issue of risk dilution in risk assessments

International Nuclear Information System (INIS)

Wilmot, R.; Robinson, P.

2004-01-01

This paper explores an issue that was first highlighted more than 20 years ago during an inquiry concerning the Sizeweli B nuclear power station in the UK. In the probabilistic safety assessment for this plant, the proponent had apparently reduced its estimates of risk by admitting to increased uncertainty about the timing of certain events. This situation is counter-intuitive, since an increase in uncertainty about the factors contributing to safety would be expected to lead to less confidence and hence to greater risk. This paradoxical situation was termed 'risk dilution' and it has been a topic of interest to reviewers of safety cases since. The recent international peer review of the Yucca Mountain performance assessments concluded that there was a potential for risk dilution in the assumptions and calculations presented. The next section describes how assumptions about the timing of events and other aspects of an assessment may lead to risk dilution, and this is followed by two examples based on recent performance assessments. The final section discusses how potential problems can be identified in safety cases, and the types of response that a regulator might adopt as a result. (authors)

A Bayesian approach to probabilistic sensitivity analysis in structured benefit-risk assessment.

Science.gov (United States)

Waddingham, Ed; Mt-Isa, Shahrul; Nixon, Richard; Ashby, Deborah

2016-01-01

Quantitative decision models such as multiple criteria decision analysis (MCDA) can be used in benefit-risk assessment to formalize trade-offs between benefits and risks, providing transparency to the assessment process. There is however no well-established method for propagating uncertainty of treatment effects data through such models to provide a sense of the variability of the benefit-risk balance. Here, we present a Bayesian statistical method that directly models the outcomes observed in randomized placebo-controlled trials and uses this to infer indirect comparisons between competing active treatments. The resulting treatment effects estimates are suitable for use within the MCDA setting, and it is possible to derive the distribution of the overall benefit-risk balance through Markov Chain Monte Carlo simulation. The method is illustrated using a case study of natalizumab for relapsing-remitting multiple sclerosis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Volcanic Hazards Assessment Support System for the Online Hazard Assessment and Risk Mitigation of Quaternary Volcanoes in the World

Directory of Open Access Journals (Sweden)

Shinji Takarada

2017-12-01

Full Text Available Volcanic hazards assessment tools are essential for risk mitigation of volcanic activities. A number of offline volcanic hazard assessment tools have been provided, but in most cases, they require relatively complex installation procedure and usage. This situation causes limited usage of volcanic hazard assessment tools among volcanologists and volcanic hazards communities. In addition, volcanic eruption chronology and detailed database of each volcano in the world are essential key information for volcanic hazard assessment, but most of them are isolated and not connected to and with each other. The Volcanic Hazard Assessment Support System aims to implement a user-friendly, WebGIS-based, open-access online system for potential hazards assessment and risk-mitigation of Quaternary volcanoes in the world. The users can get up-to-date information such as eruption chronology and geophysical monitoring data of a specific volcano using the direct link system to major volcano databases on the system. Currently, the system provides 3 simple, powerful and notable deterministic modeling simulation codes of volcanic processes, such as Energy Cone, Titan2D and Tephra2. The system provides deterministic tools because probabilistic assessment tools are normally much more computationally demanding. By using the volcano hazard assessment system, the area that would be affected by volcanic eruptions in any location near the volcano can be estimated using numerical simulations. The system is being implemented using the ASTER Global DEM covering 2790 Quaternary volcanoes in the world. The system can be used to evaluate volcanic hazards and move this toward risk-potential by overlaying the estimated distribution of volcanic gravity flows or tephra falls on major roads, houses and evacuation areas using the GIS-enabled systems. The system is developed for all users in the world who need volcanic hazards assessment tools.

Risk Assessment in the Maritime Industry

Directory of Open Access Journals (Sweden)

M. Mousavi

2017-02-01

Full Text Available Risk assessment is a well-developed field which many operators are currently applying to improve their operations and reduce their risk exposure. This paper is intended to provide an overview of the risk assessment for mariners in the Maritime transportation. The risks addressed are primarily those affecting the safety of a vessel, facility or operation. The concept of risk is defined, and the methods available to assess the risks associated with an operation are described. Regulatory requirements that have prompted the development of modern risk assessment practices are described, and future regulatory trends are discussed. There are many different analysis techniques and models that have been developed to aid in conducting risk assessments. A key to any successful risk analysis is choosing the right method (or combination of methods for the situation at hand. This is achieved through critical analysis of the available data concerning marine crises. This paper provides a brief introduction to some of the analysis methods available and suggests risk analysis approaches to support different types of decision making within the maritime transportation to cope with crises. Finally, as awareness of risk assessment increases, the benefits which can be realized through its application will continue to increase. Organizations in both the public and the private sector are becoming more and more familiar with the benefits associated with risk-based approaches to managing safety and consequently reducing crisis in maritime transportation.

The MARINA Risk Assessment Strategy: A Flexible Strategy for Efficient Information Collection and Risk Assessment of Nanomaterials.

Science.gov (United States)

Bos, Peter M J; Gottardo, Stefania; Scott-Fordsmand, Janeck J; van Tongeren, Martie; Semenzin, Elena; Fernandes, Teresa F; Hristozov, Danail; Hund-Rinke, Kerstin; Hunt, Neil; Irfan, Muhammad-Adeel; Landsiedel, Robert; Peijnenburg, Willie J G M; Sánchez Jiménez, Araceli; van Kesteren, Petra C E; Oomen, Agnes G

2015-11-27

An engineered nanomaterial (ENM) may actually consist of a population of primary particles, aggregates and agglomerates of various sizes. Furthermore, their physico-chemical characteristics may change during the various life-cycle stages. It will probably not be feasible to test all varieties of all ENMs for possible health and environmental risks. There is therefore a need to further develop the approaches for risk assessment of ENMs. Within the EU FP7 project Managing Risks of Nanoparticles (MARINA) a two-phase risk assessment strategy has been developed. In Phase 1 (Problem framing) a base set of information is considered, relevant exposure scenarios (RESs) are identified and the scope for Phase 2 (Risk assessment) is established. The relevance of an RES is indicated by information on exposure, fate/kinetics and/or hazard; these three domains are included as separate pillars that contain specific tools. Phase 2 consists of an iterative process of risk characterization, identification of data needs and integrated collection and evaluation of data on the three domains, until sufficient information is obtained to conclude on possible risks in a RES. Only data are generated that are considered to be needed for the purpose of risk assessment. A fourth pillar, risk characterization, is defined and it contains risk assessment tools. This strategy describes a flexible and efficient approach for data collection and risk assessment which is essential to ensure safety of ENMs. Further developments are needed to provide guidance and make the MARINA Risk Assessment Strategy operational. Case studies will be needed to refine the strategy.

The MARINA Risk Assessment Strategy: A Flexible Strategy for Efficient Information Collection and Risk Assessment of Nanomaterials

Directory of Open Access Journals (Sweden)

Peter M. J. Bos

2015-11-01

Full Text Available An engineered nanomaterial (ENM may actually consist of a population of primary particles, aggregates and agglomerates of various sizes. Furthermore, their physico-chemical characteristics may change during the various life-cycle stages. It will probably not be feasible to test all varieties of all ENMs for possible health and environmental risks. There is therefore a need to further develop the approaches for risk assessment of ENMs. Within the EU FP7 project Managing Risks of Nanoparticles (MARINA a two-phase risk assessment strategy has been developed. In Phase 1 (Problem framing a base set of information is considered, relevant exposure scenarios (RESs are identified and the scope for Phase 2 (Risk assessment is established. The relevance of an RES is indicated by information on exposure, fate/kinetics and/or hazard; these three domains are included as separate pillars that contain specific tools. Phase 2 consists of an iterative process of risk characterization, identification of data needs and integrated collection and evaluation of data on the three domains, until sufficient information is obtained to conclude on possible risks in a RES. Only data are generated that are considered to be needed for the purpose of risk assessment. A fourth pillar, risk characterization, is defined and it contains risk assessment tools. This strategy describes a flexible and efficient approach for data collection and risk assessment which is essential to ensure safety of ENMs. Further developments are needed to provide guidance and make the MARINA Risk Assessment Strategy operational. Case studies will be needed to refine the strategy.

Business risks, functions, methods of assessment and ways to reduce risk

Directory of Open Access Journals (Sweden)

A.V. Mihalchuk

2015-06-01

Full Text Available For successful existence in a market economy entrepreneur have to take bold actions, and this increases the risk. The article describes the concept of entrepreneurship and business risk, positive and negative aspects of functions of risk in business. Therefore, it is necessary to assess the risk properly and be able to manage it to achieve the most effective results in the market. In market conditions the problem of assessing and accounting market becomes independent theoretical and practical significance as an important component of the theory and practice of management. Risk - a key element of business activities. Development of risk situations can lead to both the occurrence of adverse effects (losses, lost profits, and positive results for a company in the form of increased profit. This article describes: the concept of entrepreneurship, risk and business risks, characteristic of positive and negative aspects of risk functions in business, methods of assessment and risk reduction, shows formulae and examples you can use to assess risk in an enterprise. Analyzing already established methods of risk assessment a number of rules were proposed in order to reduce business risk.

Risk Assessment

OpenAIRE

Hrdová, Edita

2012-01-01

This diploma thesis is focused on companies risk evaluation before endorsement of Loan deriving from business relationships. The aim of this thesis is not only to describe individual steps of risk assessment, but also perfom analysis of particular companies based on available data, i.e. Balance sheet, Profit and Loss statement and external rating and after that propose solution for each company. My analysis will be based on theoretical knowledge, further on experience related to my job role a...

HTGR accident and risk assessment

International Nuclear Information System (INIS)

Silady, F.A.; Everline, C.J.; Houghton, W.J.

1982-01-01

This paper is a synopsis of the high-temperature gas-cooled reactor probabilistic risk assessments (PRAs) performed by General Atomic Company. Principal topics presented include: HTGR safety assessments, peer interfaces, safety research, process gas explosions, quantitative safety goals, licensing applications of PRA, enhanced safety, investment risk assessments, and PRA design integration

Anthropic Risk Assessment on Biodiversity

Science.gov (United States)

Piragnolo, M.; Pirotti, F.; Vettore, A.; Salogni, G.

2013-01-01

This paper presents a methodology for risk assessment of anthropic activities on habitats and species. The method has been developed for Veneto Region, in order to simplify and improve the quality of EIA procedure (VINCA). Habitats and species, animals and plants, are protected by European Directive 92/43/EEC and 2009/147/EC but they are subject at hazard due to pollution produced by human activities. Biodiversity risks may conduct to deterioration and disturbance in ecological niches, with consequence of loss of biodiversity. Ecological risk assessment applied on Natura 2000 network, is needed to best practice of management and monitoring of environment and natural resources. Threats, pressure and activities, stress and indicators may be managed by geodatabase and analysed using GIS technology. The method used is the classic risk assessment in ecological context, and it defines the natural hazard as influence, element of risk as interference and vulnerability. Also it defines a new parameter called pressure. It uses risk matrix for the risk analysis on spatial and temporal scale. The methodology is qualitative and applies the precautionary principle in environmental assessment. The final product is a matrix which excludes the risk and could find application in the development of a territorial information system.

Risk assessment and the environment

International Nuclear Information System (INIS)

Fisk, D.J.

1992-01-01

This paper reviews the use of risk assessment techniques in the field of environment protection. I will argue that in some important instances the development of environment policy has been a source of fruitful development of a risk based methodologies. In other cases the importation of risk assessment techniques has proved much more problematic. As the scope of environmental regulation increases so does the possibility of inconsistent and arbitrary solutions to problems. The need for a more systematic approach to the development of environmental regulation has never been stronger, so it is important to understand the reasons for the mixed success of risk assessment. This applies equally to those nations with long traditions of the regulation of private sector industry and those just beginning on this course. The way ahead may be to extend our ideas of how to express risk and uncertainty. Some of the recent cause celebres of environment policy show this challenge very clearly. As an example, this paper will look at the problem of assessing the risk of man-made climate change

Risk assessment and the environment

Energy Technology Data Exchange (ETDEWEB)

Fisk, D J [Department of the Environment (United Kingdom)

1992-07-01

This paper reviews the use of risk assessment techniques in the field of environment protection. I will argue that in some important instances the development of environment policy has been a source of fruitful development of a risk based methodologies. In other cases the importation of risk assessment techniques has proved much more problematic. As the scope of environmental regulation increases so does the possibility of inconsistent and arbitrary solutions to problems. The need for a more systematic approach to the development of environmental regulation has never been stronger, so it is important to understand the reasons for the mixed success of risk assessment. This applies equally to those nations with long traditions of the regulation of private sector industry and those just beginning on this course. The way ahead may be to extend our ideas of how to express risk and uncertainty. Some of the recent cause celebres of environment policy show this challenge very clearly. As an example, this paper will look at the problem of assessing the risk of man-made climate change.

Nuclear insurance risk assessment using risk-based methodology

International Nuclear Information System (INIS)

Wendland, W.G.

1992-01-01

This paper presents American Nuclear Insurers' (ANI's) and Mutual Atomic Energy Liability Underwriters' (MAELU's) process and experience for conducting nuclear insurance risk assessments using a risk-based methodology. The process is primarily qualitative and uses traditional insurance risk assessment methods and an approach developed under the auspices of the American Society of Mechanical Engineers (ASME) in which ANI/MAELU is an active sponsor. This process assists ANI's technical resources in identifying where to look for insurance risk in an industry in which insurance exposure tends to be dynamic and nonactuarial. The process is an evolving one that also seeks to minimize the impact on insureds while maintaining a mutually agreeable risk tolerance

Simulation and Non-Simulation Based Human Reliability Analysis Approaches

Energy Technology Data Exchange (ETDEWEB)

Boring, Ronald Laurids [Idaho National Lab. (INL), Idaho Falls, ID (United States); Shirley, Rachel Elizabeth [Idaho National Lab. (INL), Idaho Falls, ID (United States); Joe, Jeffrey Clark [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2014-12-01

Part of the U.S. Department of Energy’s Light Water Reactor Sustainability (LWRS) Program, the Risk-Informed Safety Margin Characterization (RISMC) Pathway develops approaches to estimating and managing safety margins. RISMC simulations pair deterministic plant physics models with probabilistic risk models. As human interactions are an essential element of plant risk, it is necessary to integrate human actions into the RISMC risk model. In this report, we review simulation-based and non-simulation-based human reliability assessment (HRA) methods. Chapter 2 surveys non-simulation-based HRA methods. Conventional HRA methods target static Probabilistic Risk Assessments for Level 1 events. These methods would require significant modification for use in dynamic simulation of Level 2 and Level 3 events. Chapter 3 is a review of human performance models. A variety of methods and models simulate dynamic human performance; however, most of these human performance models were developed outside the risk domain and have not been used for HRA. The exception is the ADS-IDAC model, which can be thought of as a virtual operator program. This model is resource-intensive but provides a detailed model of every operator action in a given scenario, along with models of numerous factors that can influence operator performance. Finally, Chapter 4 reviews the treatment of timing of operator actions in HRA methods. This chapter is an example of one of the critical gaps between existing HRA methods and the needs of dynamic HRA. This report summarizes the foundational information needed to develop a feasible approach to modeling human interactions in the RISMC simulations.

Risk assessment for halogenated solvents

International Nuclear Information System (INIS)

Travis, C.C.

1988-01-01

A recent development in the cancer risk area is the advent of biologically based pharmacokinetic and pharmacodynamic models. These models allow for the incorporation of biological and mechanistic data into the risk assessment process. These advances will not only improve the risk assessment process for halogenated solvents but will stimulate and guide basic research in the biological area

RESIDUAL RISK ASSESSMENT: ETHYLENE OXIDE ...

Science.gov (United States)

This document describes the residual risk assessment for the Ethylene Oxide Commercial Sterilization source category. For stationary sources, section 112 (f) of the Clean Air Act requires EPA to assess risks to human health and the environment following implementation of technology-based control standards. If these technology-based control standards do not provide an ample margin of safety, then EPA is required to promulgate addtional standards. This document describes the methodology and results of the residual risk assessment performed for the Ethylene Oxide Commercial Sterilization source category. The results of this analyiss will assist EPA in determining whether a residual risk rule for this source category is appropriate.

The MCRA model for probabilistic single-compound and cumulative risk assessment of pesticides.

Science.gov (United States)

van der Voet, Hilko; de Boer, Waldo J; Kruisselbrink, Johannes W; Goedhart, Paul W; van der Heijden, Gerie W A M; Kennedy, Marc C; Boon, Polly E; van Klaveren, Jacob D

2015-05-01

Pesticide risk assessment is hampered by worst-case assumptions leading to overly pessimistic assessments. On the other hand, cumulative health effects of similar pesticides are often not taken into account. This paper describes models and a web-based software system developed in the European research project ACROPOLIS. The models are appropriate for both acute and chronic exposure assessments of single compounds and of multiple compounds in cumulative assessment groups. The software system MCRA (Monte Carlo Risk Assessment) is available for stakeholders in pesticide risk assessment at mcra.rivm.nl. We describe the MCRA implementation of the methods as advised in the 2012 EFSA Guidance on probabilistic modelling, as well as more refined methods developed in the ACROPOLIS project. The emphasis is on cumulative assessments. Two approaches, sample-based and compound-based, are contrasted. It is shown that additional data on agricultural use of pesticides may give more realistic risk assessments. Examples are given of model and software validation of acute and chronic assessments, using both simulated data and comparisons against the previous release of MCRA and against the standard software DEEM-FCID used by the Environmental Protection Agency in the USA. It is shown that the EFSA Guidance pessimistic model may not always give an appropriate modelling of exposure. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Patient Simulation for Assessment of Layperson Management of Opioid Overdose with Intranasal Naloxone in a Recently-Released Prisoner Cohort

Science.gov (United States)

Kobayashi, Leo; Green, Traci C.; Bowman, Sarah E.; Ray, Madeline C.; McKenzie, Michelle S.; Rich, Josiah D.

2016-01-01

Introduction Investigators applied simulation to an experimental program that educated, trained and assessed at-risk, volunteering prisoners on opioid overdose (OD) prevention, recognition and layperson management with intranasal (IN) naloxone. Methods Consenting inmates were assessed for OD-related experience and knowledge then exposed on-site to standardized didactics and educational DVD (without simulation). Subjects were provided with IN naloxone kits at time of release and scheduled for post-release assessment. At follow-up, subjects were evaluated for their performance of layperson opioid OD resuscitative skills during video-recorded simulations. Two investigators independently scored each subject’s resuscitative actions with a 21-item checklist; post-hoc video reviews were separately completed to adjudicate subjects’ interactions for overall benefit or harm. Results One hundred and three prisoners completed the baseline assessment and study intervention then were prescribed IN naloxone kits. One-month follow-up and simulation data were available for 85 subjects (82.5% of trained recruits) who had been released and resided in the community. Subjects’ simulation checklist median score was 12.0 (IQR 11.0–15.0) out of 21 total indicated actions. Forty-four participants (51.8%) correctly administered naloxone; 16 additional subjects (18.8%) suboptimally administered naloxone. Non-indicated actions, primarily chest compressions, were observed in 49.4% of simulations. Simulated resuscitative actions by 80 subjects (94.1%) were determined post-hoc to be beneficial overall for patients overdosing on opioids. Conclusions As part of an opioid OD prevention research program for at-risk inmates, investigators applied simulation to 1-month follow-up assessments of knowledge retention and skills acquisition in post-release participants. Simulation supplemented traditional research tools for investigation of layperson OD management. PMID:28146450

Risk assessment: An employer's perspective

International Nuclear Information System (INIS)

Williams, K.C.

1992-01-01

There is no question that a careful assessment of risk is essential for safe industrial operations. For that reason, a thoughtful analysis of the effectiveness of available risk assessment technologies is prerequisite for responsible corporate decision making. An 'employer's' perspective on risk assessment cannot be constrained by any artificial restrictions which that term may imply. In reality, all those who are involved in the execution of an industrial enterprise: managers, regulators, the affected public, and especially those employees exposed to hazards, are necessarily partners in assessment of risk. The perspective of this paper is that of the oil and gas industry, in which the author's organization, Exxon Company, International, participates. The paper addresses what Exxon requires to assess and manage risk in its worldwide operations. The author is aware, however, through contacts with industry colleagues, that some of Exxon's initiatives are representative of similar actions being taken by others. 1992 is the European Year of Safety, Health and Hygiene, coinciding with the United Kingdom's Presidency of the European Council. It is also the year in which new 'goal-setting' regulations covering safety in the U.K. offshore oil industry were put forward by the Health and Safety Commission. These regulations, based largely on Lord Cullen's recommendations following the Piper Alpha tragedy, set the pace for safety in the British North Sea and will significantly impact the safety of offshore oil installations worldwide. The requirement for risk assessment, using a systematic process of analysing and evaluating risk, is a key component of this safety regime

Risk assessment: An employer's perspective

Energy Technology Data Exchange (ETDEWEB)

Williams, K C [Exxon International (United States)

1992-07-01

There is no question that a careful assessment of risk is essential for safe industrial operations. For that reason, a thoughtful analysis of the effectiveness of available risk assessment technologies is prerequisite for responsible corporate decision making. An 'employer's' perspective on risk assessment cannot be constrained by any artificial restrictions which that term may imply. In reality, all those who are involved in the execution of an industrial enterprise: managers, regulators, the affected public, and especially those employees exposed to hazards, are necessarily partners in assessment of risk. The perspective of this paper is that of the oil and gas industry, in which the author's organization, Exxon Company, International, participates. The paper addresses what Exxon requires to assess and manage risk in its worldwide operations. The author is aware, however, through contacts with industry colleagues, that some of Exxon's initiatives are representative of similar actions being taken by others. 1992 is the European Year of Safety, Health and Hygiene, coinciding with the United Kingdom's Presidency of the European Council. It is also the year in which new 'goal-setting' regulations covering safety in the U.K. offshore oil industry were put forward by the Health and Safety Commission. These regulations, based largely on Lord Cullen's recommendations following the Piper Alpha tragedy, set the pace for safety in the British North Sea and will significantly impact the safety of offshore oil installations worldwide. The requirement for risk assessment, using a systematic process of analysing and evaluating risk, is a key component of this safety regime.

Performance Objective for Tank Farm Closure Risk Assessments

International Nuclear Information System (INIS)

MANN, F.M.; KNEPP, A.J.; BADDEN, J.

2003-01-01

To be meaningful, results from a numeric risk assessment of the consequences of an action must be compared against the standards for such an action. That is, before one disposes of waste or closes a facility with waste, one must show that the disposal or closure action protects the public health and safety and the environment. These standards are called performance objectives. Regulations requiring performing performance assessments, (whether federal ones like the Department of Energy [DOE] Order 435.1, Radioactive Waste Management and its implementing guides or Washington State ones like the regulations implementing the Washington Administrative Code [WAC] 173-340 ''Model Toxics Control Act - Cleanup''), usually require that the determination of performance objectives be one of the first steps performed. These performance objectives not only set comparison level for the numeric results, but also define the media, pathways, exposure scenarios (receptors), spatial locations, and times that the performance assessment must consider. Thus, a performance objective consists of a compliance level, place(s) of compliance, and time(s) of compliance. Performance objectives are not the levels that a regulatory agency will enforce in a permit or authorization. Those levels, often called enforcement levels, will be set in the permit or authorization. Rather, performance objectives are those levels against which the results of the numeric simulation will be compared to judge the success of the proposed cleanup or disposal actions. Additional comparison levels may be requested for information purposes, but are not officially part of the decision on the adequacy of the proposed action. To emphasize that the performance objectives discussed in this document are not regulatory performance objectives, the three components of the performance objective will be renamed in this document as assessment standard, point(s) of assessment, and time(s) of assessment. However, whenever

RELEVANCE OF PROCESS RISK ASSESSMENT IN AIRLINES

OpenAIRE

Oksana G. Feoktistova; Igor K. Turkin; Sergey V. Barinov

2017-01-01

The notion of “the concept on assumed risk” that took over from the outdated concept of absolute security is analyzed, the increasing significance of operating risk assessment at the present stage is noted. Some basic risk assessment techniques are considered. Matrix technique of risk assessment is considered more thoroughly, and it may be used in risk assessment of airlines in the context of labour protection management system.The ability to correctly assess risks and develop appropriate pre...

An abuse of risk assessment: how regulatory agencies improperly adopted LNT for cancer risk assessment.

Science.gov (United States)

Calabrese, Edward J

2015-04-01

The Genetics Panel of the National Academy of Sciences' Committee on Biological Effects of Atomic Radiation (BEAR) recommended the adoption of the linear dose-response model in 1956, abandoning the threshold dose-response for genetic risk assessments. This recommendation was quickly generalized to include somatic cells for cancer risk assessment and later was instrumental in the adoption of linearity for carcinogen risk assessment by the Environmental Protection Agency. The Genetics Panel failed to provide any scientific assessment to support this recommendation and refused to do so when later challenged by other leading scientists. Thus, the linearity model used in cancer risk assessment was based on ideology rather than science and originated with the recommendation of the NAS BEAR Committee Genetics Panel. Historical documentation in support of these conclusions is provided in the transcripts of the Panel meetings and in previously unexamined correspondence among Panel members.

Nonparametric estimation of benchmark doses in environmental risk assessment

Science.gov (United States)

Piegorsch, Walter W.; Xiong, Hui; Bhattacharya, Rabi N.; Lin, Lizhen

2013-01-01

Summary An important statistical objective in environmental risk analysis is estimation of minimum exposure levels, called benchmark doses (BMDs), that induce a pre-specified benchmark response in a dose-response experiment. In such settings, representations of the risk are traditionally based on a parametric dose-response model. It is a well-known concern, however, that if the chosen parametric form is misspecified, inaccurate and possibly unsafe low-dose inferences can result. We apply a nonparametric approach for calculating benchmark doses, based on an isotonic regression method for dose-response estimation with quantal-response data (Bhattacharya and Kong, 2007). We determine the large-sample properties of the estimator, develop bootstrap-based confidence limits on the BMDs, and explore the confidence limits’ small-sample properties via a short simulation study. An example from cancer risk assessment illustrates the calculations. PMID:23914133

A framework for combining social impact assessment and risk assessment

NARCIS (Netherlands)

Mahmoudi, Hossein; Renn, Ortwin; Vanclay, Frank; Hoffmann, Volker; Karami, Ezatollah

An increasing focus on integrative approaches is one of the current trends in impact assessment. There is potential to combine impact assessment with various other forms of assessment, such as risk assessment, to make impact assessment and the management of social risks more effective. We identify

A framework for combining social impact assessment and risk assessment

NARCIS (Netherlands)

Mahmoudi, Hossein; Renn, Ortwin; Vanclay, Frank; Hoffmann, Volker; Karami, Ezatollah

2013-01-01

An increasing focus on integrative approaches is one of the current trends in impact assessment. There is potential to combine impact assessment with various other forms of assessment, such as risk assessment, to make impact assessment and the management of social risks more effective. We identify

Risk indices in comparative risk assessment studies

International Nuclear Information System (INIS)

Hubert, P.

1984-01-01

More than a decade ago the development of comparative risk assessment studies aroused overwhelming interest. There was no doubt that data on the health and safety aspects of energy systems would greatly benefit, or even end, the debate on nuclear energy. Although such attempts are still strongly supported, the rose-coloured expectations of the early days have faded. The high uncertainties, and the contradictory aspect, of the first results might explain this evolution. The loose connection between the range of computed risk indices and the questions on which the debate was focused is another reason for this decline in interest. Important research work is being carried out aiming at reducing the different kinds of uncertainties. Rather than the uncertainties, the paper considers the meaning of available risk indices and proposes more significant indices with respect to the goals of risk assessment. First, the indices which are of frequent use in comparative studies are listed. The stress is put on a French comparative study from which most examples are drawn. Secondly, the increase in magnitude of the indices and the decrease in the attributability of the risk to a given system is shown to be a consequence of the trend towards more comprehensive analyses. Thirdly, the ambiguity of such indices as the collective occupational risk is underlined, and a possible solution is suggested. Whenever risk assessments are related to pragmatic decision making problems it is possible to find satisfactory risk indices. The development of cost-effectiveness analyses and the proposals for quantitative safety goals clearly demonstrate this point. In the field of comparison of social impacts some proposals are made, but there remain some gaps still to be filled. (author)

Aspects regarding explosion risk assessment

Directory of Open Access Journals (Sweden)

Părăian Mihaela

2017-01-01

Full Text Available Explosive risk occurs in all activities involving flammable substances in the form of gases, vapors, mists or dusts which, in mixture with air, can generate an explosive atmosphere. As explosions can cause human losses and huge material damage, the assessment of the explosion risk and the establishment of appropriate measures to reduce it to acceptable levels according to the standards and standards in force is of particular importance for the safety and health of people and goods.There is no yet a recognized method of assessing the explosion risk, but regardless of the applied method, the likelihood of an explosive atmosphere occurrence has to be determined, together with the occurrence of an efficient ignition source and the magnitude of foreseeable consequences. In assessment processes, consequences analysis has a secondary importance since it’s likely that explosions would always involve considerable damage, starting from important material damages and up to human damages that could lead to death.The purpose of the work is to highlight the important principles and elements to be taken into account for a specific risk assessment. An essential element in assessing the risk of explosion in workplaces where explosive atmospheres may occur is technical installations and personal protective equipment (PPE that must be designed, manufactured, installed and maintained so that they cannot generate a source of ignition. Explosion prevention and protection requirements are governed by specific norms and standards, and a main part of the explosion risk assessment is related to the assessment of the compliance of the equipment / installation with these requirements.

Probabilistic risk assessment of insecticide concentrations in agricultural surface waters: a critical appraisal.

Science.gov (United States)

Stehle, Sebastian; Knäbel, Anja; Schulz, Ralf

2013-08-01

Due to the specific modes of action and application patterns of agricultural insecticides, the insecticide exposure of agricultural surface waters is characterized by infrequent and short-term insecticide concentration peaks of high ecotoxicological relevance with implications for both monitoring and risk assessment. Here, we apply several fixed-interval strategies and an event-based sampling strategy to two generalized and two realistic insecticide exposure patterns for typical agricultural streams derived from FOCUS exposure modeling using Monte Carlo simulations. Sampling based on regular intervals was found to be inadequate for the detection of transient insecticide concentrations, whereas event-triggered sampling successfully detected all exposure incidences at substantially lower analytical costs. Our study proves that probabilistic risk assessment (PRA) concepts in their present forms are not appropriate for a thorough evaluation of insecticide exposure. Despite claims that the PRA approach uses all available data to assess exposure and enhances risk assessment realism, we demonstrate that this concept is severely biased by the amount of insecticide concentrations below detection limits and therefore by the sampling designs. Moreover, actual insecticide exposure is of almost no relevance for PRA threshold level exceedance frequencies and consequential risk assessment outcomes. Therefore, we propose a concept that features a field-relevant ecological risk analysis of agricultural insecticide surface water exposure. Our study quantifies for the first time the environmental and economic consequences of inappropriate monitoring and risk assessment concepts used for the evaluation of short-term peak surface water pollutants such as insecticides.

Bayesian Hierarchical Structure for Quantifying Population Variability to Inform Probabilistic Health Risk Assessments.

Science.gov (United States)

Shao, Kan; Allen, Bruce C; Wheeler, Matthew W

2017-10-01

Human variability is a very important factor considered in human health risk assessment for protecting sensitive populations from chemical exposure. Traditionally, to account for this variability, an interhuman uncertainty factor is applied to lower the exposure limit. However, using a fixed uncertainty factor rather than probabilistically accounting for human variability can hardly support probabilistic risk assessment advocated by a number of researchers; new methods are needed to probabilistically quantify human population variability. We propose a Bayesian hierarchical model to quantify variability among different populations. This approach jointly characterizes the distribution of risk at background exposure and the sensitivity of response to exposure, which are commonly represented by model parameters. We demonstrate, through both an application to real data and a simulation study, that using the proposed hierarchical structure adequately characterizes variability across different populations. © 2016 Society for Risk Analysis.

Uncertainty propagation in probabilistic risk assessment: A comparative study

International Nuclear Information System (INIS)

Ahmed, S.; Metcalf, D.R.; Pegram, J.W.

1982-01-01

Three uncertainty propagation techniques, namely method of moments, discrete probability distribution (DPD), and Monte Carlo simulation, generally used in probabilistic risk assessment, are compared and conclusions drawn in terms of the accuracy of the results. For small uncertainty in the basic event unavailabilities, the three methods give similar results. For large uncertainty, the method of moments is in error, and the appropriate method is to propagate uncertainty in the discrete form either by DPD method without sampling or by Monte Carlo. (orig.)

Chlorine transportation risk assessment

International Nuclear Information System (INIS)

Lautkaski, Risto; Mankamo, Tuomas.

1977-02-01

An assessment has been made on the toxication risk of the population due to the bulk rail transportation of liquid chlorine in Finland. Fourteen typical rail accidents were selected and their probability was estimated using the accident file of the Finnish State Railways. The probability of a chlorine leak was assessed for each type of accident separately using four leak size categories. The assessed leakage probability was dominated by station accidents, especially by collisions of a chlorine tanker and a locomotive. Toxication hazard areas were estimated for the leak categories. A simple model was constructed to describe the centring of the densely populated areas along the railway line. A comparison was made between the obtained risk and some other risks including those due to nuclear reactor accidents. (author)

Probabilistic risk assessment, Volume I

International Nuclear Information System (INIS)

Anon.

1982-01-01

This book contains 158 papers presented at the International Topical Meeting on Probabilistic Risk Assessment held by the American Nuclear Society (ANS) and the European Nuclear Society (ENS) in Port Chester, New York in 1981. The meeting was second in a series of three. The main focus of the meeting was on the safety of light water reactors. The papers discuss safety goals and risk assessment. Quantitative safety goals, risk assessment in non-nuclear technologies, and operational experience and data base are also covered. Included is an address by Dr. Chauncey Starr

Risk assessment in maritime transportation

International Nuclear Information System (INIS)

Soares, C. Guedes; Teixeira, A.P.

2001-01-01

A review is presented of different approaches to quantify the risk in maritime transportation. The discussion of several accident statistics provides a global assessment of the risk levels and its differentiation in ship types and main types of ship losses. Early studies in the probability of ship loss by foundering and capsizing are reviewed. The approaches used to assess the risk of structural design are addressed. Finally a brief account is given of recent development of using formal safety assessments to support decision making on legislation applicable internationally to maritime transportation

Framework for ecological risk assessment

International Nuclear Information System (INIS)

Rodier, D.; Norton, S.

1992-02-01

Increased interest in ecological issues such as global climate change, habitat loss, acid deposition, reduced biological diversity, and the ecological impacts of pesticides and toxic chemicals prompts this U.S. Environmental Protection Agency (EPA) report, A Framework for Ecological Risk Assessment ('Framework Report'). The report describes basic elements, or a framework, for evaluating scientific information on the adverse effects of physical and chemical stressors on the environment. The framework offers starting principles and a simple structure as guidance for current ecological risk assessments and as a foundation for future EPA proposals for risk assessment guidelines

[A quantitative risk assessment model of salmonella on carcass in poultry slaughterhouse].

Science.gov (United States)

Zhang, Yu; Chen, Yuzhen; Hu, Chunguang; Zhang, Huaning; Bi, Zhenwang; Bi, Zhenqiang

2015-05-01

To construct a quantitative risk assessment model of salmonella on carcass in poultry slaughterhouse and to find out effective interventions to reduce salmonella contamination. We constructed a modular process risk model (MPRM) from evisceration to chilling in Excel Sheet using the data of the process parameters in poultry and the Salmomella concentration surveillance of Jinan in 2012. The MPRM was simulated by @ risk software. The concentration of salmonella on carcass after chilling was 1.96MPN/g which was calculated by model. The sensitive analysis indicated that the correlation coefficient of the concentration of salmonella after defeathering and in chilling pool were 0.84 and 0.34,which were the primary factors to the concentration of salmonella on carcass after chilling. The study provided a quantitative assessment model structure for salmonella on carcass in poultry slaughterhouse. The risk manager could control the contamination of salmonella on carcass after chilling by reducing the concentration of salmonella after defeathering and in chilling pool.

Risk assessment instruments in clinical practice.

Science.gov (United States)

Côté, Gilles; Crocker, Anne G; Nicholls, Tonia L; Seto, Michael C

2012-04-01

To determine whether the items in one of the most widely validated instruments of violence risk assessment, the Historical-Clinical-Risk Management-20 (HCR-20), are used in review board hearings to assess the risk of violence by people found Not Criminally Responsible on account of Mental Disorder (NCRMD). This study was conducted from October 2004 to August 2006 in Quebec's sole forensic psychiatric hospital and 2 large civil psychiatric hospitals designated for the care of people declared NCRMD in the Montreal metropolitan area. The risk assessments presented by clinicians at annual review board hearings and the boards' rationale for the release or detention of people found NCRMD were contrasted with the risk assessments conducted by the research team using the HCR-20. The final sample was comprised of 96 men. Very few of the risk factors identified by prior research (HCR-20 items) were mentioned in the hearing process, whether in clinical reports, discussions during the hearing, or in the disposition justification. The findings confirm that there remains a significant gap between research evidence and risk assessment practice.

Reevaluating Interrater Reliability in Offender Risk Assessment

NARCIS (Netherlands)

van der Knaap, L.M.; Leenarts, L.E.W.; Born, M.P.; Oosterveld, P.

2012-01-01

Offender risk and needs assessment, one of the pillars of the risk-need-responsivity model of offender rehabilitation, usually depends on raters assessing offender risk and needs. The few available studies of interrater reliability in offender risk assessment are, however, limited in the

A system simulation to enhance stockpile stewardship (ASSESS)

International Nuclear Information System (INIS)

Yoshimura, A.S.; Plantenga, T.D.; Napolitano, L.M.; Johnson, M.M.

1997-01-01

This paper describes the ASSESS project, whose goal is to construct a policy driven enterprise simulation of the DOE nuclear weapons complex (DOE/NWC). ASSESS encompasses the full range of stockpile stewardship activities by incorporating simulation component models that are developed and managed by local experts. ASSESS runs on a heterogeneous distributed computing environment and implements multi-layered user access capabilities. ASSESS allows the user to create hypothetical policies governing stockpile stewardship, simulate the resulting operation of the DOE/NWC, and analyze the relative impact of each policy

Quantitative risk assessment system (QRAS)

Science.gov (United States)

Weinstock, Robert M (Inventor); Smidts, Carol S (Inventor); Mosleh, Ali (Inventor); Chang, Yung-Hsien (Inventor); Swaminathan, Sankaran (Inventor); Groen, Francisco J (Inventor); Tan, Zhibin (Inventor)

2001-01-01

A quantitative risk assessment system (QRAS) builds a risk model of a system for which risk of failure is being assessed, then analyzes the risk of the system corresponding to the risk model. The QRAS performs sensitivity analysis of the risk model by altering fundamental components and quantifications built into the risk model, then re-analyzes the risk of the system using the modifications. More particularly, the risk model is built by building a hierarchy, creating a mission timeline, quantifying failure modes, and building/editing event sequence diagrams. Multiplicities, dependencies, and redundancies of the system are included in the risk model. For analysis runs, a fixed baseline is first constructed and stored. This baseline contains the lowest level scenarios, preserved in event tree structure. The analysis runs, at any level of the hierarchy and below, access this baseline for risk quantitative computation as well as ranking of particular risks. A standalone Tool Box capability exists, allowing the user to store application programs within QRAS.

Application of wildfire simulation models for risk analysis

Science.gov (United States)

Ager, A.; Finney, M.

2009-04-01

lakes showed markedly reduced BP. When wildfire probabilities were combined with habitat loss functions for the Northern spotted owl, we observed expected loss from a random wildfire event ranging from 0.0 to 9.4% with a mean value of 1.5%. Expected loss was strongly correlated with BP for owl habitat, apparently because fires at very low intensities caused understory mortality and reduced stand canopy closure below minimum levels. The effect of simulating strategic fuel treatments on a subunit of the area resulted in significant decrease in expected loss of owl habitat. The effect of changing weather from a severe to mild (97th to 70th) percentile weather resulted in a dramatic 8-fold drop in BP and reduced the average wildfire size. However, the reduction was not uniform with the departures well correlated with specific fuel models. In total, this work demonstrated the application of wildfire spread models to quantitative risk assessment for fuels management on federally-managed lands in the U.S. The analyses revealed spatial variation in BP that is useful in prioritizing fuels treatments and guiding other wildfire mitigation activities. The work also illuminated the conflict between biodiversity conservation efforts on federally-managed lands and the high wildfire risk on fire-prone landscapes.

Ecosystem services as assessment endpoints for ecological risk assessment.

Science.gov (United States)

Munns, Wayne R; Rea, Anne W; Suter, Glenn W; Martin, Lawrence; Blake-Hedges, Lynne; Crk, Tanja; Davis, Christine; Ferreira, Gina; Jordan, Steve; Mahoney, Michele; Barron, Mace G

2016-07-01

Ecosystem services are defined as the outputs of ecological processes that contribute to human welfare or have the potential to do so in the future. Those outputs include food and drinking water, clean air and water, and pollinated crops. The need to protect the services provided by natural systems has been recognized previously, but ecosystem services have not been formally incorporated into ecological risk assessment practice in a general way in the United States. Endpoints used conventionally in ecological risk assessment, derived directly from the state of the ecosystem (e.g., biophysical structure and processes), and endpoints based on ecosystem services serve different purposes. Conventional endpoints are ecologically important and susceptible entities and attributes that are protected under US laws and regulations. Ecosystem service endpoints are a conceptual and analytical step beyond conventional endpoints and are intended to complement conventional endpoints by linking and extending endpoints to goods and services with more obvious benefit to humans. Conventional endpoints can be related to ecosystem services even when the latter are not considered explicitly during problem formulation. To advance the use of ecosystem service endpoints in ecological risk assessment, the US Environmental Protection Agency's Risk Assessment Forum has added generic endpoints based on ecosystem services (ES-GEAE) to the original 2003 set of generic ecological assessment endpoints (GEAEs). Like conventional GEAEs, ES-GEAEs are defined by an entity and an attribute. Also like conventional GEAEs, ES-GEAEs are broadly described and will need to be made specific when applied to individual assessments. Adoption of ecosystem services as a type of assessment endpoint is intended to improve the value of risk assessment to environmental decision making, linking ecological risk to human well-being, and providing an improved means of communicating those risks. Integr Environ Assess Manag

Flood-risk mapping: contributions towards an enhanced assessment of extreme events and associated risks

Directory of Open Access Journals (Sweden)

B. Büchele

2006-01-01

Full Text Available Currently, a shift from classical flood protection as engineering task towards integrated flood risk management concepts can be observed. In this context, a more consequent consideration of extreme events which exceed the design event of flood protection structures and failure scenarios such as dike breaches have to be investigated. Therefore, this study aims to enhance existing methods for hazard and risk assessment for extreme events and is divided into three parts. In the first part, a regionalization approach for flood peak discharges was further developed and substantiated, especially regarding recurrence intervals of 200 to 10 000 years and a large number of small ungauged catchments. Model comparisons show that more confidence in such flood estimates for ungauged areas and very long recurrence intervals may be given as implied by statistical analysis alone. The hydraulic simulation in the second part is oriented towards hazard mapping and risk analyses covering the whole spectrum of relevant flood events. As the hydrodynamic simulation is directly coupled with a GIS, the results can be easily processed as local inundation depths for spatial risk analyses. For this, a new GIS-based software tool was developed, being presented in the third part, which enables estimations of the direct flood damage to single buildings or areas based on different established stage-damage functions. Furthermore, a new multifactorial approach for damage estimation is presented, aiming at the improvement of damage estimation on local scale by considering factors like building quality, contamination and precautionary measures. The methods and results from this study form the base for comprehensive risk analyses and flood management strategies.

Hanford Site baseline risk assessment methodology

International Nuclear Information System (INIS)

1993-03-01

This methodology has been developed to prepare human health and environmental evaluations of risk as part of the Comprehensive Environmental Response, Compensation, and Liability Act remedial investigations (RIs) and the Resource Conservation and Recovery Act facility investigations (FIs) performed at the Hanford Site pursuant to the Hanford Federal Facility Agreement and Consent Order referred to as the Tri-Party Agreement. Development of the methodology has been undertaken so that Hanford Site risk assessments are consistent with current regulations and guidance, while providing direction on flexible, ambiguous, or undefined aspects of the guidance. The methodology identifies Site-specific risk assessment considerations and integrates them with approaches for evaluating human and environmental risk that can be factored into the risk assessment program supporting the Hanford Site cleanup mission. Consequently, the methodology will enhance the preparation and review of individual risk assessments at the Hanford Site

Integrating pixel- and polygon-based approaches to wildfire risk assessment: Application to a high-value watershed on the Pike and San Isabel National Forests, Colorado, USA

Science.gov (United States)

Matthew P. Thompson; Julie W. Gilbertson-Day; Joe H. Scott

2015-01-01

We develop a novel risk assessment approach that integrates complementary, yet distinct, spatial modeling approaches currently used in wildfire risk assessment. Motivation for this work stems largely from limitations of existing stochastic wildfire simulation systems, which can generate pixel-based outputs of fire behavior as well as polygon-based outputs of simulated...

A National Needs Assessment to Identify Technical Procedures in Vascular Surgery for Simulation Based Training

DEFF Research Database (Denmark)

Nayahangan, L J; Konge, L; Schroeder, T V

2017-01-01

to identify technical procedures that vascular surgeons should learn. Round 2 was a survey that used a needs assessment formula to explore the frequency of procedures, the number of surgeons performing each procedure, risk and/or discomfort, and feasibility for simulation based training. Round 3 involved...... eliminated, resulting in a final prioritised list of 19 technical procedures. Conclusion A national needs assessment using a standardised Delphi method identified a list of procedures that are highly suitable and may provide the basis for future simulation based training programs for vascular surgeons......Objectives and background Practical skills training in vascular surgery is facing challenges because of an increased number of endovascular procedures and fewer open procedures, as well as a move away from the traditional principle of “learning by doing.” This change has established simulation...

Risk of portfolio with simulated returns based on copula model

Science.gov (United States)

Razak, Ruzanna Ab; Ismail, Noriszura

2015-02-01

The commonly used tool for measuring risk of a portfolio with equally weighted stocks is variance-covariance method. Under extreme circumstances, this method leads to significant underestimation of actual risk due to its multivariate normality assumption of the joint distribution of stocks. The purpose of this research is to compare the actual risk of portfolio with the simulated risk of portfolio in which the joint distribution of two return series is predetermined. The data used is daily stock prices from the ASEAN market for the period January 2000 to December 2012. The copula approach is applied to capture the time varying dependence among the return series. The results shows that the chosen copula families are not suitable to present the dependence structures of each bivariate returns. Exception for the Philippines-Thailand pair where by t copula distribution appears to be the appropriate choice to depict its dependence. Assuming that the t copula distribution is the joint distribution of each paired series, simulated returns is generated and value-at-risk (VaR) is then applied to evaluate the risk of each portfolio consisting of two simulated return series. The VaR estimates was found to be symmetrical due to the simulation of returns via elliptical copula-GARCH approach. By comparison, it is found that the actual risks are underestimated for all pairs of portfolios except for Philippines-Thailand. This study was able to show that disregard of the non-normal dependence structure of two series will result underestimation of actual risk of the portfolio.

RELEVANCE OF PROCESS RISK ASSESSMENT IN AIRLINES

Directory of Open Access Journals (Sweden)

Oksana G. Feoktistova

2017-01-01

Full Text Available The notion of “the concept on assumed risk” that took over from the outdated concept of absolute security is analyzed, the increasing significance of operating risk assessment at the present stage is noted. Some basic risk assessment techniques are considered. Matrix technique of risk assessment is considered more thoroughly, and it may be used in risk assessment of airlines in the context of labour protection management system.The ability to correctly assess risks and develop appropriate precautionary measures will allow airlines to avoid incidents leading to drastic consequences for staff, as well as to direct and indirect costs for the enterprise among which there could be singled out both direct property damage and loss of profit and expenses connected to incident investigation, penalty and compensation payment, loss of business reputation and so on. To reduce the rate of accidents and to develop safe activities skills for airlines staff a risk assessment chart is supposed to be implemented, which will be an efficient accidents prevention involving the staff in the process and making them follow safe working conditions.Process risk assessment is an integral part of assessment of the whole enterprise activity and work efficiency of a department and particular workers evaluation system. Labour protection activity should be based on risk identification and its control. Risk assessment is a keystone of labour protection activity planning.

Discrete Fracture Network Models for Risk Assessment of Carbon Sequestration in Coal

Energy Technology Data Exchange (ETDEWEB)

Jack Pashin; Guohai Jin; Chunmiao Zheng; Song Chen; Marcella McIntyre

2008-07-01

A software package called DFNModeler has been developed to assess the potential risks associated with carbon sequestration in coal. Natural fractures provide the principal conduits for fluid flow in coal-bearing strata, and these fractures present the most tangible risks for the leakage of injected carbon dioxide. The objectives of this study were to develop discrete fracture network (DFN) modeling tools for risk assessment and to use these tools to assess risks in the Black Warrior Basin of Alabama, where coal-bearing strata have high potential for carbon sequestration and enhanced coalbed methane recovery. DFNModeler provides a user-friendly interface for the construction, visualization, and analysis of DFN models. DFNModeler employs an OpenGL graphics engine that enables real-time manipulation of DFN models. Analytical capabilities in DFNModeler include display of structural and hydrologic parameters, compartmentalization analysis, and fluid pathways analysis. DFN models can be exported to third-party software packages for flow modeling. DFN models were constructed to simulate fracturing in coal-bearing strata of the upper Pottsville Formation in the Black Warrior Basin. Outcrops and wireline cores were used to characterize fracture systems, which include joint systems, cleat systems, and fault-related shear fractures. DFN models were constructed to simulate jointing, cleating, faulting, and hydraulic fracturing. Analysis of DFN models indicates that strata-bound jointing compartmentalizes the Pottsville hydrologic system and helps protect shallow aquifers from injection operations at reservoir depth. Analysis of fault zones, however, suggests that faulting can facilitate cross-formational flow. For this reason, faults should be avoided when siting injection wells. DFN-based flow models constructed in TOUGH2 indicate that fracture aperture and connectivity are critical variables affecting the leakage of injected CO{sub 2} from coal. Highly transmissive joints

Nuclear power plant training simulator fidelity assessment

International Nuclear Information System (INIS)

Carter, R.J.; Laughery, K.R.

1985-01-01

The fidelity assessment portion of a methodology for evaluating nuclear power plant simulation facilities in regard to their appropriateness for conducting the Nuclear Regulatory Commission's operating test was described. The need for fidelity assessment, data sources, and fidelity data to be collected are addressed. Fidelity data recording, collection, and analysis are discussed. The processes for drawing conclusions from the fidelity assessment and evaluating the adequacy of the simulator control-room layout were presented. 3 refs

Simulating the Risk of Liver Fluke Infection using a Mechanistic Hydro-epidemiological Model

Science.gov (United States)

Beltrame, Ludovica; Dunne, Toby; Rose, Hannah; Walker, Josephine; Morgan, Eric; Vickerman, Peter; Wagener, Thorsten

2016-04-01

Liver Fluke (Fasciola hepatica) is a common parasite found in livestock and responsible for considerable economic losses throughout the world. Risk of infection is strongly influenced by climatic and hydrological conditions, which characterise the host environment for parasite development and transmission. Despite on-going control efforts, increases in fluke outbreaks have been reported in recent years in the UK, and have been often attributed to climate change. Currently used fluke risk models are based on empirical relationships derived between historical climate and incidence data. However, hydro-climate conditions are becoming increasingly non-stationary due to climate change and direct anthropogenic impacts such as land use change, making empirical models unsuitable for simulating future risk. In this study we introduce a mechanistic hydro-epidemiological model for Liver Fluke, which explicitly simulates habitat suitability for disease development in space and time, representing the parasite life cycle in connection with key environmental conditions. The model is used to assess patterns of Liver Fluke risk for two catchments in the UK under current and potential future climate conditions. Comparisons are made with a widely used empirical model employing different datasets, including data from regional veterinary laboratories. Results suggest that mechanistic models can achieve adequate predictive ability and support adaptive fluke control strategies under climate change scenarios.

Uncertainty quantification in flood risk assessment

Science.gov (United States)

Blöschl, Günter; Hall, Julia; Kiss, Andrea; Parajka, Juraj; Perdigão, Rui A. P.; Rogger, Magdalena; Salinas, José Luis; Viglione, Alberto

2017-04-01

Uncertainty is inherent to flood risk assessments because of the complexity of the human-water system, which is characterised by nonlinearities and interdependencies, because of limited knowledge about system properties and because of cognitive biases in human perception and decision-making. On top of the uncertainty associated with the assessment of the existing risk to extreme events, additional uncertainty arises because of temporal changes in the system due to climate change, modifications of the environment, population growth and the associated increase in assets. Novel risk assessment concepts are needed that take into account all these sources of uncertainty. They should be based on the understanding of how flood extremes are generated and how they change over time. They should also account for the dynamics of risk perception of decision makers and population in the floodplains. In this talk we discuss these novel risk assessment concepts through examples from Flood Frequency Hydrology, Socio-Hydrology and Predictions Under Change. We believe that uncertainty quantification in flood risk assessment should lead to a robust approach of integrated flood risk management aiming at enhancing resilience rather than searching for optimal defense strategies.

Reevaluating Interrater Reliability in Offender Risk Assessment

Science.gov (United States)

van der Knaap, Leontien M.; Leenarts, Laura E. W.; Born, Marise Ph.; Oosterveld, Paul

2012-01-01

Offender risk and needs assessment, one of the pillars of the risk-need-responsivity model of offender rehabilitation, usually depends on raters assessing offender risk and needs. The few available studies of interrater reliability in offender risk assessment are, however, limited in the generalizability of their results. The present study…

Enhancing the ecological risk assessment process.

Science.gov (United States)

Dale, Virginia H; Biddinger, Gregory R; Newman, Michael C; Oris, James T; Suter, Glenn W; Thompson, Timothy; Armitage, Thomas M; Meyer, Judith L; Allen-King, Richelle M; Burton, G Allen; Chapman, Peter M; Conquest, Loveday L; Fernandez, Ivan J; Landis, Wayne G; Master, Lawrence L; Mitsch, William J; Mueller, Thomas C; Rabeni, Charles F; Rodewald, Amanda D; Sanders, James G; van Heerden, Ivor L

2008-07-01

The Ecological Processes and Effects Committee of the US Environmental Protection Agency Science Advisory Board conducted a self-initiated study and convened a public workshop to characterize the state of the ecological risk assessment (ERA), with a view toward advancing the science and application of the process. That survey and analysis of ERA in decision making shows that such assessments have been most effective when clear management goals were included in the problem formulation; translated into information needs; and developed in collaboration with decision makers, assessors, scientists, and stakeholders. This process is best facilitated when risk managers, risk assessors, and stakeholders are engaged in an ongoing dialogue about problem formulation. Identification and acknowledgment of uncertainties that have the potential to profoundly affect the results and outcome of risk assessments also improves assessment effectiveness. Thus we suggest 1) through peer review of ERAs be conducted at the problem formulation stage and 2) the predictive power of risk-based decision making be expanded to reduce uncertainties through analytical and methodological approaches like life cycle analysis. Risk assessment and monitoring programs need better integration to reduce uncertainty and to evaluate risk management decision outcomes. Postdecision audit programs should be initiated to evaluate the environmental outcomes of risk-based decisions. In addition, a process should be developed to demonstrate how monitoring data can be used to reduce uncertainties. Ecological risk assessments should include the effects of chemical and nonchemical stressors at multiple levels of biological organization and spatial scale, and the extent and resolution of the pertinent scales and levels of organization should be explicitly considered during problem formulation. An approach to interpreting lines of evidence and weight of evidence is critically needed for complex assessments, and it would

Peer-Assessment Debriefing Instrument (PADI): Assessing Faculty Effectiveness in Simulation Education.

Science.gov (United States)

Saylor, Jennifer L; Wainwright, Susan F; Herge, E A; Pohlig, Ryan T

2016-01-01

Evaluating the debriefing skill of faculty in simulations is essential but often challenging. The Peer Assessment Debriefing Instrument (PADI) is a self and peer assessment designed to assess a debriefers' effectiveness and is grounded in current scientific debriefing literature and peer review methodology. This pilot study tested the PADI at three institutions during 10 different healthcare debriefing sessions. The PADI is useful to faculty and administrators of simulation centers by demonstrating ongoing quality improvement and as a guide to train new debriefers.

A framework for combining social impact assessment and risk assessment

Energy Technology Data Exchange (ETDEWEB)

Mahmoudi, Hossein, E-mail: mahmoudi@uni-hohenheim.de [Department of Social Sciences in Agriculture, University of Hohenheim (Germany); Environmental Sciences Research Institute, Shahid Beheshti University, G.C. (Iran, Islamic Republic of); Renn, Ortwin [Department of Technology and Environmental Sociology (and DIALOGIK), University of Stuttgart (Germany); Vanclay, Frank [Department of Cultural Geography, Faculty of Spatial Sciences, University of Groningen, Groningen (Netherlands); Hoffmann, Volker [Department of Social Sciences in Agriculture, University of Hohenheim (Germany); Karami, Ezatollah [College of Agriculture, Shiraz University, Shiraz (Iran, Islamic Republic of)

2013-11-15

An increasing focus on integrative approaches is one of the current trends in impact assessment. There is potential to combine impact assessment with various other forms of assessment, such as risk assessment, to make impact assessment and the management of social risks more effective. We identify the common features of social impact assessment (SIA) and social risk assessment (SRA), and discuss the merits of a combined approach. A hybrid model combining SIA and SRA to form a new approach called, ‘risk and social impact assessment’ (RSIA) is introduced. RSIA expands the capacity of SIA to evaluate and manage the social impacts of risky projects such as nuclear energy as well as natural hazards and disasters such as droughts and floods. We outline the three stages of RSIA, namely: impact identification, impact assessment, and impact management. -- Highlights: • A hybrid model to combine SIA and SRA namely RSIA is proposed. • RSIA can provide the proper mechanism to assess social impacts of natural hazards. • RSIA can play the role of ex-post as well as ex-ante assessment. • For some complicated and sensitive cases like nuclear energy, conducting a RSIA is necessary.

A framework for combining social impact assessment and risk assessment

International Nuclear Information System (INIS)

Mahmoudi, Hossein; Renn, Ortwin; Vanclay, Frank; Hoffmann, Volker; Karami, Ezatollah

2013-01-01

An increasing focus on integrative approaches is one of the current trends in impact assessment. There is potential to combine impact assessment with various other forms of assessment, such as risk assessment, to make impact assessment and the management of social risks more effective. We identify the common features of social impact assessment (SIA) and social risk assessment (SRA), and discuss the merits of a combined approach. A hybrid model combining SIA and SRA to form a new approach called, ‘risk and social impact assessment’ (RSIA) is introduced. RSIA expands the capacity of SIA to evaluate and manage the social impacts of risky projects such as nuclear energy as well as natural hazards and disasters such as droughts and floods. We outline the three stages of RSIA, namely: impact identification, impact assessment, and impact management. -- Highlights: • A hybrid model to combine SIA and SRA namely RSIA is proposed. • RSIA can provide the proper mechanism to assess social impacts of natural hazards. • RSIA can play the role of ex-post as well as ex-ante assessment. • For some complicated and sensitive cases like nuclear energy, conducting a RSIA is necessary

Risk assessment [Chapter 9

Science.gov (United States)

Dennis S. Ojima; Louis R. Iverson; Brent L. Sohngen; James M. Vose; Christopher W. Woodall; Grant M. Domke; David L. Peterson; Jeremy S. Littell; Stephen N. Matthews; Anantha M. Prasad; Matthew P. Peters; Gary W. Yohe; Megan M. Friggens

2014-01-01

What is "risk" in the context of climate change? How can a "risk-based framework" help assess the effects of climate change and develop adaptation priorities? Risk can be described by the likelihood of an impact occurring and the magnitude of the consequences of the impact (Yohe 2010) (Fig. 9.1). High-magnitude impacts are always...

A rear-end collision risk assessment model based on drivers' collision avoidance process under influences of cell phone use and gender-A driving simulator based study.

Science.gov (United States)

Li, Xiaomeng; Yan, Xuedong; Wu, Jiawei; Radwan, Essam; Zhang, Yuting

2016-12-01

Driver's collision avoidance performance has a direct link to the collision risk and crash severity. Previous studies demonstrated that the distracted driving, such as using a cell phone while driving, disrupted the driver's performance on road. This study aimed to investigate the manner and extent to which cell phone use and driver's gender affected driving performance and collision risk in a rear-end collision avoidance process. Forty-two licensed drivers completed the driving simulation experiment in three phone use conditions: no phone use, hands-free, and hand-held, in which the drivers drove in a car-following situation with potential rear-end collision risks caused by the leading vehicle's sudden deceleration. Based on the experiment data, a rear-end collision risk assessment model was developed to assess the influence of cell phone use and driver's gender. The cell phone use and driver's gender were found to be significant factors that affected the braking performances in the rear-end collision avoidance process, including the brake reaction time, the deceleration adjusting time and the maximum deceleration rate. The minimum headway distance between the leading vehicle and the simulator during the rear-end collision avoidance process was the final output variable, which could be used to measure the rear-end collision risk and judge whether a collision occurred. The results showed that although cell phone use drivers took some compensatory behaviors in the collision avoidance process to reduce the mental workload, the collision risk in cell phone use conditions was still higher than that without the phone use. More importantly, the results proved that the hands-free condition did not eliminate the safety problem associated with distracted driving because it impaired the driving performance in the same way as much as the use of hand-held phones. In addition, the gender effect indicated that although female drivers had longer reaction time than male drivers in

Tensit - a novel probabilistic simulation tool for safety assessments. Tests and verifications using biosphere models

Energy Technology Data Exchange (ETDEWEB)

Jones, Jakob; Vahlund, Fredrik; Kautsky, Ulrik

2004-06-01

This report documents the verification of a new simulation tool for dose assessment put together in a package under the name Tensit (Technical Nuclide Simulation Tool). The tool is developed to solve differential equation systems describing transport and decay of radionuclides. It is capable of handling both deterministic and probabilistic simulations. The verifications undertaken shows good results. Exceptions exist only where the reference results are unclear. Tensit utilise and connects two separate commercial softwares. The equation solving capability is derived from the Matlab/Simulink software environment to which Tensit adds a library of interconnectable building blocks. Probabilistic simulations are provided through a statistical software named at{sub R}isk that communicates with Matlab/Simulink. More information about these softwares can be found at www.palisade.com and www.mathworks.com. The underlying intention of developing this new tool has been to make available a cost efficient and easy to use means for advanced dose assessment simulations. The mentioned benefits are gained both through the graphical user interface provided by Simulink and at{sub R}isk, and the use of numerical equation solving routines in Matlab. To verify Tensit's numerical correctness, an implementation was done of the biosphere modules for dose assessments used in the earlier safety assessment project SR 97. Acquired probabilistic results for deterministic as well as probabilistic simulations have been compared with documented values. Additional verification has been made both with another simulation tool named AMBER and also against the international test case from PSACOIN named Level 1B. This report documents the models used for verification with equations and parameter values so that the results can be recreated. For a background and a more detailed description of the underlying processes in the models, the reader is referred to the original references. Finally, in the

Concerning ethical risk assessment

International Nuclear Information System (INIS)

Boeckle, F.

1991-01-01

After a fundamental consideration of the concept of responsibility and 'long-term responsibility' for late sequelae, the problems of an ehtical assessment of risks were illustrated: The concept of risk itself poses three problems - predicting the probability of occurrence, assessing the damage = subjective classification of the degree of damage, determining whether the advantages outweigh the risks. It is not possible to weigh the advantages and risks against each other without assessing the goals and the priorities which have been set. Here ethics is called for, because it concerns itself with the reasonableness of evaluative decisions. Its task is to enable us to become aware of and comprehend our system of values in all of its complexity in reference to real life. Ethics can only fulfill its task if it helps us to adopt an integral perspective, i.e. if it centers on the human being. 'One must assess all technical and economic innovations in terms of whether they are beneficial to the development of mankind on a long-term basis. They are only to be legitimized insofar as they prove themselves to be a means of liberating mankind and contributing to his sense of dignity and identity, as a means of bringing human beings together and encouraging them to care for one another, and as a means of protecting the natural basis of our existence. (orig./HSCH) [de

Ecological risk assessment

National Research Council Canada - National Science Library

Suter, Glenn W; Barnthouse, L. W. (Lawrence W)

2007-01-01

Ecological risk assessment is commonly applied to the regulation of chemicals, the remediation of contaminated sites, the monitoring of importation of exotic organisms, the management of watersheds...

Probabilistic Risk Assessment for Astronaut Post Flight Bone Fracture

Science.gov (United States)

Lewandowski, Beth; Myers, Jerry; Licata, Angelo

2015-01-01

Introduction: Space flight potentially reduces the loading that bone can resist before fracture. This reduction in bone integrity may result from a combination of factors, the most common reported as reduction in astronaut BMD. Although evaluating the condition of bones continues to be a critical aspect of understanding space flight fracture risk, defining the loading regime, whether on earth, in microgravity, or in reduced gravity on a planetary surface, remains a significant component of estimating the fracture risks to astronauts. This presentation summarizes the concepts, development, and application of NASA's Bone Fracture Risk Module (BFxRM) to understanding pre-, post, and in mission astronaut bone fracture risk. The overview includes an assessment of contributing factors utilized in the BFxRM and illustrates how new information, such as biomechanics of space suit design or better understanding of post flight activities may influence astronaut fracture risk. Opportunities for the bone mineral research community to contribute to future model development are also discussed. Methods: To investigate the conditions in which spaceflight induced changes to bone plays a critical role in post-flight fracture probability, we implement a modified version of the NASA Bone Fracture Risk Model (BFxRM). Modifications included incorporation of variations in physiological characteristics, post-flight recovery rate, and variations in lateral fall conditions within the probabilistic simulation parameter space. The modeled fracture probability estimates for different loading scenarios at preflight and at 0 and 365 days post-flight time periods are compared. Results: For simple lateral side falls, mean post-flight fracture probability is elevated over mean preflight fracture probability due to spaceflight induced BMD loss and is not fully recovered at 365 days post-flight. In the case of more energetic falls, such as from elevated heights or with the addition of lateral movement

ICUD-0530 Scenario based risk assessment of the dispersion of E-coli from combined sewer overflow to a fresh-water lake

DEFF Research Database (Denmark)

Rasmussen, Michael Robdrup; Thorndahl, Søren Liedtke; Nielsen, Jesper Ellerbæk

2017-01-01

A scenario based risk assessment method is used to evaluate how combined sewer overflow (CSO) affects a nearby bathing beach in Skanderborg, Denmark. The method combines an urban drainage model with a 3D CFD model to pre-simulate 60 different scenarios, used for assessing the risk of poor bathing...

Crop modelling for integrated assessment of risk to food production from climate change

DEFF Research Database (Denmark)

Ewert, F.; Rötter, R.P.; Bindi, M.

2015-01-01

. However, progress on the number of simulated crops, uncertainty propagation related to model parameters and structure, adaptations and scaling are less advanced and lagging behind IAM demands. The limitations are considered substantial and apply to a different extent to all crop models. Overcoming...... climate change risks to food production and to which extent crop models comply with IAM demands. Considerable progress has been made in modelling effects of climate variables, where crop models best satisfy IAM demands. Demands are partly satisfied for simulating commonly required assessment variables...

A risk communication case study: the Nevada risk assessment/management program

International Nuclear Information System (INIS)

Hechanova, A.E.

2001-01-01

The Nevada Risk Assessment/Management Program is part of a national effort by the U.S. Department of Energy (Grant DE-FG01-96EW56093) to develop new sources of information and approaches to risk assessment, risk management, risk communication and public outreach as these objectives relate to the ecological and human health effects of radioactive and hazardous material management and site remediation activities. This paper reviews the innovation behind the Nevada Risk Assessment/Management Program and presents a synopsis of the effort that began in 1995 and will officially conclude on April 30, 2000. (author)

Risk analysis of gravity dam instability using credibility theory Monte Carlo simulation model.

Science.gov (United States)

Xin, Cao; Chongshi, Gu

2016-01-01

Risk analysis of gravity dam stability involves complicated uncertainty in many design parameters and measured data. Stability failure risk ratio described jointly by probability and possibility has deficiency in characterization of influence of fuzzy factors and representation of the likelihood of risk occurrence in practical engineering. In this article, credibility theory is applied into stability failure risk analysis of gravity dam. Stability of gravity dam is viewed as a hybrid event considering both fuzziness and randomness of failure criterion, design parameters and measured data. Credibility distribution function is conducted as a novel way to represent uncertainty of influence factors of gravity dam stability. And combining with Monte Carlo simulation, corresponding calculation method and procedure are proposed. Based on a dam section, a detailed application of the modeling approach on risk calculation of both dam foundation and double sliding surfaces is provided. The results show that, the present method is feasible to be applied on analysis of stability failure risk for gravity dams. The risk assessment obtained can reflect influence of both sorts of uncertainty, and is suitable as an index value.

Caries risk assessment in children

DEFF Research Database (Denmark)

Twetman, S

2016-01-01

PURPOSE: To summarise the findings of recent systematic reviews (SR) covering caries risk assessment in children, updated with recent primary studies. METHODS: A search for relevant papers published 2012-2014 was conducted in electronic databases. The systematic reviews were quality assessed...... displayed a high risk of bias. CONCLUSIONS: Based on the present summary of literature, it may be concluded: (1) a caries risk assessment should be carried out at the child's first dental visit and reassessments should be done during childhood (D); (2) multivariate models display a better accuracy than...... the use of single predictors and this is especially true for preschool children (C); (3) there is no clearly superior method to predict future caries and no evidence to support the use of one model, program, or technology before the other (C); and (4) the risk category should be linked to appropriate...

Instability risk analysis and risk assessment system establishment of underground storage caverns in bedded salt rock

Science.gov (United States)

Jing, Wenjun; Zhao, Yan

2018-02-01

Stability is an important part of geotechnical engineering research. The operating experiences of underground storage caverns in salt rock all around the world show that the stability of the caverns is the key problem of safe operation. Currently, the combination of theoretical analysis and numerical simulation are the mainly adopts method of reserve stability analysis. This paper introduces the concept of risk into the stability analysis of underground geotechnical structure, and studies the instability of underground storage cavern in salt rock from the perspective of risk analysis. Firstly, the definition and classification of cavern instability risk is proposed, and the damage mechanism is analyzed from the mechanical angle. Then the main stability evaluating indicators of cavern instability risk are proposed, and an evaluation method of cavern instability risk is put forward. Finally, the established cavern instability risk assessment system is applied to the analysis and prediction of cavern instability risk after 30 years of operation in a proposed storage cavern group in the Huai’an salt mine. This research can provide a useful theoretical base for the safe operation and management of underground storage caverns in salt rock.

[Regional atmospheric environment risk source identification and assessment].

Science.gov (United States)

Zhang, Xiao-Chun; Chen, Wei-Ping; Ma, Chun; Zhan, Shui-Fen; Jiao, Wen-Tao

2012-12-01

Identification and assessment for atmospheric environment risk source plays an important role in regional atmospheric risk assessment and regional atmospheric pollution prevention and control. The likelihood exposure and consequence assessment method (LEC method) and the Delphi method were employed to build a fast and effective method for identification and assessment of regional atmospheric environment risk sources. This method was applied to the case study of a large coal transportation port in North China. The assessment results showed that the risk characteristics and the harm degree of regional atmospheric environment risk source were in line with the actual situation. Fast and effective identification and assessment of risk source has laid an important foundation for the regional atmospheric environmental risk assessment and regional atmospheric pollution prevention and control.

A Probabilistic Risk Assessment For Emergency Preparedness

International Nuclear Information System (INIS)

Lee, Joomyung; Jae, Moosung; Ahn, Kwangil

2013-01-01

The importance of nuclear power plant PSA has grown up all over the world due to this incident. The main concern of this study is to develop a methodology to carry on an emergency preparedness evaluation and to set an exclusive area, or the emergency response area boundary in order to apply it to domestic reference plants. This study also focuses on evaluating the risk parameter of major nuclides through a sensitivity analysis and a safety assessment by calculating the population dose, early fatality, and cancer fatality rates. A methodology for an emergency preparedness, which can be applied to evaluate the damage of the radioactive release as well as to assess the safety of the accident scenario of a nuclear power plant, has been developed and applied for the reference plants in Korea. By applying a source term analysis, an exclusive zone based on the radioactive dose is obtained. And the results of the health effect assessment based on the release fraction of specific nuclides to public with an effective emergency response activity have been simulated. A methodology utilizing the Level 3 PSA with the actual emergency response activities has been developed and applied to typical nuclear accident situations. The plausible standard for performing an emergency plan is suggested and the valuable information regarding emergency preparedness has been produced in this study. For further works, the sensitivity study on important parameters will be performed to simulate the actual severe accident situations such as sheltering, evacuation, and emergency response activities

OPPT workplan risk assessment for Trichloroethylene ...

Science.gov (United States)

The assessment will focus on uses of TCE as a degreaser and in consumer products used by individuals in the arts/crafts field. Given the range of endpoints (cancer, non-cancer; the latter includes potential effects on the developing fetus), it is expected that susceptible populations would be children (as bystanders physically near the actual consumer use of the products) and adults of all ages (including pregnant women). Thus, the assessment will focus on all human/lifestages. EPA anticipates issuing draft risk assessments for public review and comment as they are completed. At the conclusion of the review process, if an assessment of specific uses indicates significant risk, EPA will evaluate and pursue appropriate risk reduction actions, as warranted. If an assessment indicates no significant risk, EPA will conclude its current work on assessment of those specified targeted uses of that chemical. Over time, additional chemicals will be added to the work plan as more data are developed and more chemicals screened.

Measurement, simulation and uncertainty assessment of implant heating during MRI

International Nuclear Information System (INIS)

Neufeld, E; Kuehn, S; Kuster, N; Szekely, G

2009-01-01

The heating of tissues around implants during MRI can pose severe health risks, and careful evaluation is required for leads to be labeled as MR conditionally safe. A recent interlaboratory comparison study has shown that different groups can produce widely varying results (sometimes with more than a factor of 5 difference) when performing measurements according to current guidelines. To determine the related difficulties and to derive optimized procedures, two different generic lead structures have been investigated in this study by using state-of-the-art temperature and dosimetric probes, as well as simulations for which detailed uncertainty budgets have been determined. The agreement between simulations and measurements is well within the combined uncertainty. The study revealed that the uncertainty can be kept below 17% if appropriate instrumentation and procedures are applied. Optimized experimental assessment techniques can be derived from the findings presented herein.

Measurement, simulation and uncertainty assessment of implant heating during MRI

Energy Technology Data Exchange (ETDEWEB)

Neufeld, E; Kuehn, S; Kuster, N [Foundation for Research on Information Technologies in Society (IT' IS), Zeughausstr. 43, 8004 Zurich (Switzerland); Szekely, G [Computer Vision Laboratory, Swiss Federal Institute of Technology (ETHZ), Sternwartstr 7, ETH Zentrum, 8092 Zurich (Switzerland)], E-mail: neufeld@itis.ethz.ch

2009-07-07

The heating of tissues around implants during MRI can pose severe health risks, and careful evaluation is required for leads to be labeled as MR conditionally safe. A recent interlaboratory comparison study has shown that different groups can produce widely varying results (sometimes with more than a factor of 5 difference) when performing measurements according to current guidelines. To determine the related difficulties and to derive optimized procedures, two different generic lead structures have been investigated in this study by using state-of-the-art temperature and dosimetric probes, as well as simulations for which detailed uncertainty budgets have been determined. The agreement between simulations and measurements is well within the combined uncertainty. The study revealed that the uncertainty can be kept below 17% if appropriate instrumentation and procedures are applied. Optimized experimental assessment techniques can be derived from the findings presented herein.

System Analysis and Risk Assessment System (SARA), Version 4.0

International Nuclear Information System (INIS)

Russell, K.D.; Sattison, M.B.; Skinner, N.L.; Stewart, H.D.; Wood, S.T.

1992-02-01

This NUREG is the reference manual for the System Analysis and Risk Assessment (SARA) System Version 4.0, a microcomputer-based system used to analyze the safety issues of a family [i.e., a power plant, a manufacturing facility, any facility on which a probabilistic risk assessment (PRA) might be performed]. The SARA data base contains PRA data for the dominant accident sequences of a family and descriptive information about the family including event trees, fault trees, and system model diagrams. The number of facility data bases that can be accessed is limited only by the amount of disk storage available. To simulate changes to family systems, SARA users change the failure rates of initiating and basic events and/or modify the structure of the cut sets that make up the event trees, fault trees, and systems. The user then evaluates the effects of these changes through the recalculation of the resultant accident sequence probabilities and importance measures. The results are displayed in tables and graphs

Regional risk assessment of environmental contamination from oil pipelines

International Nuclear Information System (INIS)

Pelmulder, S.D.; Eguchi, R.T.

1991-01-01

This paper presents a methodology for assessing the risk of environmental contamination from oil pipeline leaks due to earthquakes. Risk is measured both as volume of oil released and remediation cost. The methodology was developed for use on a regional scale and thus relies on a limited amount of input data. Monte Carlo techniques are used to simulate earthquake events, while a deterministic model is used to estimate the volume of oil released at a particular site. A library of cost models is used to estimate the contamination and resulting remediation cost based on the volume of oil released and the general site conditions. This methodology has been implemented in a computer program, OILOSS, and the results are presented as annual frequency of exceedence curves for volume of oil released and cost of remediation

Ecological Risk Assessment of the Southern Fujian Golden Triangle in China Based on Regional Transportation Development

Directory of Open Access Journals (Sweden)

Xinyi Yang

2018-06-01

Full Text Available Regional transportation development (RTD is an important stressor of urban agglomeration ecosystems. Groundwater recharge potential may be adversely affected when natural soil is replaced by impervious materials. To systematically identify the urban agglomeration ecological risk (UAER of RTD in the southern Fujian Golden Triangle, water regulation was used as an assessment endpoint, and RTD was considered the stressor. We used the Soil Conservation Service Curve Number method (SCS-CN to analyze the internal relationship between the assessment endpoint and the stressor factors. Then, a multi-level risk characterization method was used to show the evolutionary process of risk, and to provide a scientific basis for the management of UAER. Based on the current RTD plan, the UAER assessment shows that there is a 0.90 probability of that the risk distribution results will occur by 2030. The intensity of stress from arterial roads on the urban agglomeration ecosystem is greater than that of the railway system. By considering the development of the railway system as a factor in the stress of RTD, this study of UAER assessment differs from past studies of urban ecological risk assessment, since the latter considers only highways. We also propose a systematic method of risk assessment simulation-prediction.

Tools for Microbiological risk assessment

DEFF Research Database (Denmark)

Bassett, john; Nauta, Maarten; Lindqvist, Roland

can increase the understanding of microbiological risks in foods. It is timely to inform food safety professionals about the availability and utility of MRA tools. Therefore, the focus of this report is to aid the food safety manager by providing a concise summary of the tools available for the MRA......Microbiological Risk Assessment (MRA) has emerged as a comprehensive and systematic approach for addressing the risk of pathogens in specific foods and/or processes. At government level, MRA is increasingly recognised as a structured and objective approach to understand the level of risk in a given...... food/pathogen scenario. Tools developed so far support qualitative and quantitative assessments of the risk that a food pathogen poses to a particular population. Risk can be expressed as absolute numbers or as relative (ranked) risks. The food industry is beginning to appreciate that the tools for MRA...

Modeling for operational event risk assessment

International Nuclear Information System (INIS)

Sattison, M.B.

1997-01-01

The U.S. Nuclear Regulatory Commission has been using risk models to evaluate the risk significance of operational events in U.S. commercial nuclear power plants for more seventeen years. During that time, the models have evolved in response to the advances in risk assessment technology and insights gained with experience. Evaluation techniques fall into two categories, initiating event assessments and condition assessments. The models used for these analyses have become uniquely specialized for just this purpose

Risk assessment of forensic patients: nurses' role.

Science.gov (United States)

Encinares, Maxima; McMaster, Jeff James; McNamee, Jim

2005-03-01

One of the unique roles of forensic nurses is to conduct risk assessments. Establishing a therapeutic nurse-patient relationship helps forensic nurses perform accurate and useful risk assessments. Accurate risk assessments can facilitate formulation of individualized risk management plans, designed to meet patients' needs and ensure public safety. The importance of forensic nurses' knowledge and application of appropriate communication and proper documentation cannot be overemphasized.

Ethical dimensions in assessing technical risks

International Nuclear Information System (INIS)

Birnbacher, D.

1991-01-01

Contrary to the present tendency of partially impact-independent technology assessment, the author does not see a difference between a risk-benefit analysis and an ethical technology assessment. As long as the risk-benefit analysis is truly comprehensive, both fall together. This does not mean that convictions of those who have their doubts about some new technologies, independently of impact assessments, may be disregarded in purely consequential risk evaluations. On the contrary, qualms of representatives of these principles, just as any other stable non-acceptance, have to be included as aggravating negative elements in technology assessments. (orig./HSCH) [de

Total cardiovascular disease risk assessment: a review.

LENUS (Irish Health Repository)

Cooney, Marie Therese

2011-09-01

The high risk strategy for the prevention of cardiovascular disease (CVD) requires an assessment of an individual\\'s total CVD risk so that the most intensive risk factor management can be directed towards those at highest risk. Here we review developments in the assessment and estimation of total CVD risk.

Risk assessment of carcinogens in food

International Nuclear Information System (INIS)

Barlow, Susan; Schlatter, Josef

2010-01-01

Approaches for the risk assessment of carcinogens in food have evolved as scientific knowledge has advanced. Early methods allowed little more than hazard identification and an indication of carcinogenic potency. Evaluation of the modes of action of carcinogens and their broad division into genotoxic and epigenetic (non-genotoxic, non-DNA reactive) carcinogens have played an increasing role in determining the approach followed and provide possibilities for more detailed risk characterisation, including provision of quantitative estimates of risk. Reliance on experimental animal data for the majority of risk assessments and the fact that human exposures to dietary carcinogens are often orders of magnitude below doses used in experimental studies has provided a fertile ground for discussion and diverging views on the most appropriate way to offer risk assessment advice. Approaches used by national and international bodies differ, with some offering numerical estimates of potential risks to human health, while others express considerable reservations about the validity of quantitative approaches requiring extrapolation of dose-response data below the observed range and instead offer qualitative advice. Recognising that qualitative advice alone does not provide risk managers with information on which to prioritise the need for risk management actions, a 'margin of exposure' approach for substances that are both genotoxic and carcinogenic has been developed, which is now being used by the World Health Organization and the European Food Safety Authority. This review describes the evolution of risk assessment advice on carcinogens and discusses examples of ways in which carcinogens in food have been assessed in Europe.

Risk assessment of carcinogens in food.

Science.gov (United States)

Barlow, Susan; Schlatter, Josef

2010-03-01

Approaches for the risk assessment of carcinogens in food have evolved as scientific knowledge has advanced. Early methods allowed little more than hazard identification and an indication of carcinogenic potency. Evaluation of the modes of action of carcinogens and their broad division into genotoxic and epigenetic (non-genotoxic, non-DNA reactive) carcinogens have played an increasing role in determining the approach followed and provide possibilities for more detailed risk characterisation, including provision of quantitative estimates of risk. Reliance on experimental animal data for the majority of risk assessments and the fact that human exposures to dietary carcinogens are often orders of magnitude below doses used in experimental studies has provided a fertile ground for discussion and diverging views on the most appropriate way to offer risk assessment advice. Approaches used by national and international bodies differ, with some offering numerical estimates of potential risks to human health, while others express considerable reservations about the validity of quantitative approaches requiring extrapolation of dose-response data below the observed range and instead offer qualitative advice. Recognising that qualitative advice alone does not provide risk managers with information on which to prioritise the need for risk management actions, a "margin of exposure" approach for substances that are both genotoxic and carcinogenic has been developed, which is now being used by the World Health Organization and the European Food Safety Authority. This review describes the evolution of risk assessment advice on carcinogens and discusses examples of ways in which carcinogens in food have been assessed in Europe.

Depleted uranium residual radiological risk assessment for Kosovo sites

International Nuclear Information System (INIS)

Durante, Marco; Pugliese, Mariagabriella

2003-01-01

During the recent conflict in Yugoslavia, depleted uranium rounds were employed and were left in the battlefield. Health concern is related to the risk arising from contamination of areas in Kosovo with depleted uranium penetrators and dust. Although chemical toxicity is the most significant health risk related to uranium, radiation exposure has been allegedly related to cancers among veterans of the Balkan conflict. Uranium munitions are considered to be a source of radiological contamination of the environment. Based on measurements and estimates from the recent Balkan Task Force UNEP mission in Kosovo, we have estimated effective doses to resident populations using a well-established food-web mathematical model (RESRAD code). The UNEP mission did not find any evidence of widespread contamination in Kosovo. Rather than the actual measurements, we elected to use a desk assessment scenario (Reference Case) proposed by the UNEP group as the source term for computer simulations. Specific applications to two Kosovo sites (Planeja village and Vranovac hill) are described. Results of the simulations suggest that radiation doses from water-independent pathways are negligible (annual doses below 30 μSv). A small radiological risk is expected from contamination of the groundwater in conditions of effective leaching and low distribution coefficient of uranium metal. Under the assumptions of the Reference Case, significant radiological doses (>1 mSv/year) might be achieved after many years from the conflict through water-dependent pathways. Even in this worst-case scenario, DU radiological risk would be far overshadowed by its chemical toxicity

[Using sequential indicator simulation method to define risk areas of soil heavy metals in farmland.

Science.gov (United States)

Yang, Hao; Song, Ying Qiang; Hu, Yue Ming; Chen, Fei Xiang; Zhang, Rui

2018-05-01

The heavy metals in soil have serious impacts on safety, ecological environment and human health due to their toxicity and accumulation. It is necessary to efficiently identify the risk area of heavy metals in farmland soil, which is of important significance for environment protection, pollution warning and farmland risk control. We collected 204 samples and analyzed the contents of seven kinds of heavy metals (Cu, Zn, Pb, Cd, Cr, As, Hg) in Zengcheng District of Guangzhou, China. In order to overcame the problems of the data, including the limitation of abnormal values and skewness distribution and the smooth effect with the traditional kriging methods, we used sequential indicator simulation method (SISIM) to define the spatial distribution of heavy metals, and combined Hakanson index method to identify potential ecological risk area of heavy metals in farmland. The results showed that: (1) Based on the similar accuracy of spatial prediction of soil heavy metals, the SISIM had a better expression of detail rebuild than ordinary kriging in small scale area. Compared to indicator kriging, the SISIM had less error rate (4.9%-17.1%) in uncertainty evaluation of heavy-metal risk identification. The SISIM had less smooth effect and was more applicable to simulate the spatial uncertainty assessment of soil heavy metals and risk identification. (2) There was no pollution in Zengcheng's farmland. Moderate potential ecological risk was found in the southern part of study area due to enterprise production, human activities, and river sediments. This study combined the sequential indicator simulation with Hakanson risk index method, and effectively overcame the outlier information loss and smooth effect of traditional kriging method. It provided a new way to identify the soil heavy metal risk area of farmland in uneven sampling.

Impact of shutdown risk on risk-based assessment of technical specifications

International Nuclear Information System (INIS)

Deriot, S.

1992-10-01

This paper describes the current work performed by the Research and Development Division of EDF concerning risk-based assessment of Operating Technical Specifications (OTS). The current risk-based assessment of OTS at EDF is presented. Then, the level 1 Probabilistic Safety Assessment of unit 3 of the Paluel nuclear power station (called PSA 1300) is described. It is fully computerized and takes into account the risk in shutdown states. A case study is presented. It shows that the fact of considering shutdown risk suggests that the current OTS should be modified

An integrated stochastic environmental risk assessment method and its application to a petroleum-contaminated site

International Nuclear Information System (INIS)

Liu, L.; Fuller, G.A.; Huang, G.H.

1999-01-01

Contamination of soil and water and the resulting threat to public health and the environment are the frequent results of oil spills, leaks and other releases of gasoline, diesel fuel, heating oil and other petroleum products. Integrating an analytical groundwater solute transport model within its general framework, this paper proposes an integrated stochastic risk assessment method and ways to apply it to petroleum-contaminated sites. Both the analytical solute transport model and the general risk assessment framework are solved by the Monte Carlo simulation technique for approaching the theoretical output distribution. Results of this study show that the total cancer risk has approximately log-normal distribution, irrespective of the fact that a variety of distributions were used to define the related parameters. It is claimed that the method can improve the effectiveness of the risk assessment for subsurface, and provide useful result for site remediation decisions. 23 refs., 3 tabs., 4 figs

The use of importance sampling in a trial assessment to obtain converged estimates of radiological risk

International Nuclear Information System (INIS)

Johnson, K.; Lucas, R.

1986-12-01

In developing a methodology for assessing potential sites for the disposal of radioactive wastes, the Department of the Environment has conducted a series of trial assessment exercises. In order to produce converged estimates of radiological risk using the SYVAC A/C simulation system an efficient sampling procedure is required. Previous work has demonstrated that importance sampling can substantially increase sampling efficiency. This study used importance sampling to produce converged estimates of risk for the first DoE trial assessment. Four major nuclide chains were analysed. In each case importance sampling produced converged risk estimates with between 10 and 170 times fewer runs of the SYVAC A/C model. This increase in sampling efficiency can reduce the total elapsed time required to obtain a converged estimate of risk from one nuclide chain by a factor of 20. The results of this study suggests that the use of importance sampling could reduce the elapsed time required to perform a risk assessment of a potential site by a factor of ten. (author)

Simulation-based assessments in health professional education: a systematic review.

Science.gov (United States)

Ryall, Tayne; Judd, Belinda K; Gordon, Christopher J

2016-01-01

The use of simulation in health professional education has increased rapidly over the past 2 decades. While simulation has predominantly been used to train health professionals and students for a variety of clinically related situations, there is an increasing trend to use simulation as an assessment tool, especially for the development of technical-based skills required during clinical practice. However, there is a lack of evidence about the effectiveness of using simulation for the assessment of competency. Therefore, the aim of this systematic review was to examine simulation as an assessment tool of technical skills across health professional education. A systematic review of Cumulative Index to Nursing and Allied Health Literature (CINAHL), Education Resources Information Center (ERIC), Medical Literature Analysis and Retrieval System Online (Medline), and Web of Science databases was used to identify research studies published in English between 2000 and 2015 reporting on measures of validity, reliability, or feasibility of simulation as an assessment tool. The McMasters Critical Review for quantitative studies was used to determine methodological value on all full-text reviewed articles. Simulation techniques using human patient simulators, standardized patients, task trainers, and virtual reality were included. A total of 1,064 articles were identified using search criteria, and 67 full-text articles were screened for eligibility. Twenty-one articles were included in the final review. The findings indicated that simulation was more robust when used as an assessment in combination with other assessment tools and when more than one simulation scenario was used. Limitations of the research papers included small participant numbers, poor methodological quality, and predominance of studies from medicine, which preclude any definite conclusions. Simulation has now been embedded across a range of health professional education and it appears that simulation

Engineering aspects of probabilistic risk assessment

International Nuclear Information System (INIS)

vonHerrmann, J.L.; Wood, P.J.

1984-01-01

Over the last decade, the use of probabilistic risk assessment (PRA) in the nuclear industry has expanded significantly. In these analyses the probabilities of experiencing certain undesired events (for example, a plant accident which results in damage to the nuclear fuel) are estimated and the consequences of these events are evaluated in terms of some common measure. These probabilities and consequences are then combined to form a representation of the risk associated with the plant studied. In the relatively short history of probabilistic risk assessment of nuclear power plants, the primary motivation for these studies has been the quantitative assessment of public risk associated with a single plant or group of plants. Accordingly, the primary product of most PRAs performed to date has been a 'risk curve' in which the probability (or expected frequency) of exceeding a certain consequence level is plotted against that consequence. The most common goal of these assessments has been to demonstrate the 'acceptability' of the calculated risk by comparison of the resultant risk curve to risk curves associated with other plants or with other societal risks. Presented here are brief descriptions of some alternate applications of PRAs, a discussion of how these other applications compare or contrast with the currently popular uses of PRA, and a discussion of the relative benefits of each

Insurance World in Transition: Changes in Global Risk Taking and Risk Assessment

Science.gov (United States)

Michel, Gero; Tiampo, Kristy

2015-04-01

Catastrophe insurance risk assessment, risk taking, and regulation has evolved over the last 20 years and is gearing up for significant further change in the years ahead. Changes in regulation and influx of capital have put profit margins for catastrophe risk products under pressure despite the fact that changes in climate as well as increasing insurance penetration is expected to heighten demand. As a result, reinsurance strategies are moving away from catastrophe risk. In addition, lower margins require cheaper and more efficient risk assessment methods and processes which are contrary to evolving analytical tools and methods that had increased expenses in line with growing margins over the last decade. New capital providers are less familiar with and less willing to accept complex supply chains for risk management, relationship-driven business and tedious data exchange and management processes. Risk takers claim new measures and ask for more flexibility in the use of tools. The current concepts of catastrophe insurance risk assessment are hence under thorough scrutiny. This presentation deals with the changing landscape in catastrophe insurance risk assessment and risk hedging and discusses changes in catastrophe risk assessment products and demand. How likely is it that private, small and nimble hazard and risk consulting groups - increasingly emanating from larger science organizations - will replace large established firms in their role to assess risk? What role do public-private academic partnerships play in assuming risk for catastrophe insurance and what role could they play in the future? What are the opportunities and downsides of the current changes in risk taking and hedging? What is needed from the scientific community in order to fill the gaps in risk management and who is likely to take advantage of the current changes?

Assessing flood risk at the global scale: model setup, results, and sensitivity

International Nuclear Information System (INIS)

Ward, Philip J; Jongman, Brenden; Weiland, Frederiek Sperna; Winsemius, Hessel C; Bouwman, Arno; Ligtvoet, Willem; Van Beek, Rens; Bierkens, Marc F P

2013-01-01

Globally, economic losses from flooding exceeded $19 billion in 2012, and are rising rapidly. Hence, there is an increasing need for global-scale flood risk assessments, also within the context of integrated global assessments. We have developed and validated a model cascade for producing global flood risk maps, based on numerous flood return-periods. Validation results indicate that the model simulates interannual fluctuations in flood impacts well. The cascade involves: hydrological and hydraulic modelling; extreme value statistics; inundation modelling; flood impact modelling; and estimating annual expected impacts. The initial results estimate global impacts for several indicators, for example annual expected exposed population (169 million); and annual expected exposed GDP ($1383 billion). These results are relatively insensitive to the extreme value distribution employed to estimate low frequency flood volumes. However, they are extremely sensitive to the assumed flood protection standard; developing a database of such standards should be a research priority. Also, results are sensitive to the use of two different climate forcing datasets. The impact model can easily accommodate new, user-defined, impact indicators. We envisage several applications, for example: identifying risk hotspots; calculating macro-scale risk for the insurance industry and large companies; and assessing potential benefits (and costs) of adaptation measures. (letter)

A Quantitative Risk Assessment Model Involving Frequency and Threat Degree under Line-of-Business Services for Infrastructure of Emerging Sensor Networks.

Science.gov (United States)

Jing, Xu; Hu, Hanwen; Yang, Huijun; Au, Man Ho; Li, Shuqin; Xiong, Naixue; Imran, Muhammad; Vasilakos, Athanasios V

2017-03-21

The prospect of Line-of-Business Services (LoBSs) for infrastructure of Emerging Sensor Networks (ESNs) is exciting. Access control remains a top challenge in this scenario as the service provider's server contains a lot of valuable resources. LoBSs' users are very diverse as they may come from a wide range of locations with vastly different characteristics. Cost of joining could be low and in many cases, intruders are eligible users conducting malicious actions. As a result, user access should be adjusted dynamically. Assessing LoBSs' risk dynamically based on both frequency and threat degree of malicious operations is therefore necessary. In this paper, we proposed a Quantitative Risk Assessment Model (QRAM) involving frequency and threat degree based on value at risk. To quantify the threat degree as an elementary intrusion effort, we amend the influence coefficient of risk indexes in the network security situation assessment model. To quantify threat frequency as intrusion trace effort, we make use of multiple behavior information fusion. Under the influence of intrusion trace, we adapt the historical simulation method of value at risk to dynamically access LoBSs' risk. Simulation based on existing data is used to select appropriate parameters for QRAM. Our simulation results show that the duration influence on elementary intrusion effort is reasonable when the normalized parameter is 1000. Likewise, the time window of intrusion trace and the weight between objective risk and subjective risk can be set to 10 s and 0.5, respectively. While our focus is to develop QRAM for assessing the risk of LoBSs for infrastructure of ESNs dynamically involving frequency and threat degree, we believe it is also appropriate for other scenarios in cloud computing.

A Quantitative Risk Assessment Model Involving Frequency and Threat Degree under Line-of-Business Services for Infrastructure of Emerging Sensor Networks

Science.gov (United States)

Jing, Xu; Hu, Hanwen; Yang, Huijun; Au, Man Ho; Li, Shuqin; Xiong, Naixue; Imran, Muhammad; Vasilakos, Athanasios V.

2017-01-01

The prospect of Line-of-Business Services (LoBSs) for infrastructure of Emerging Sensor Networks (ESNs) is exciting. Access control remains a top challenge in this scenario as the service provider’s server contains a lot of valuable resources. LoBSs’ users are very diverse as they may come from a wide range of locations with vastly different characteristics. Cost of joining could be low and in many cases, intruders are eligible users conducting malicious actions. As a result, user access should be adjusted dynamically. Assessing LoBSs’ risk dynamically based on both frequency and threat degree of malicious operations is therefore necessary. In this paper, we proposed a Quantitative Risk Assessment Model (QRAM) involving frequency and threat degree based on value at risk. To quantify the threat degree as an elementary intrusion effort, we amend the influence coefficient of risk indexes in the network security situation assessment model. To quantify threat frequency as intrusion trace effort, we make use of multiple behavior information fusion. Under the influence of intrusion trace, we adapt the historical simulation method of value at risk to dynamically access LoBSs’ risk. Simulation based on existing data is used to select appropriate parameters for QRAM. Our simulation results show that the duration influence on elementary intrusion effort is reasonable when the normalized parameter is 1000. Likewise, the time window of intrusion trace and the weight between objective risk and subjective risk can be set to 10 s and 0.5, respectively. While our focus is to develop QRAM for assessing the risk of LoBSs for infrastructure of ESNs dynamically involving frequency and threat degree, we believe it is also appropriate for other scenarios in cloud computing. PMID:28335569

An introductory guide to uncertainty analysis in environmental and health risk assessment. Environmental Restoration Program

International Nuclear Information System (INIS)

Hammonds, J.S.; Hoffman, F.O.; Bartell, S.M.

1994-12-01

This report presents guidelines for evaluating uncertainty in mathematical equations and computer models applied to assess human health and environmental risk. Uncertainty analyses involve the propagation of uncertainty in model parameters and model structure to obtain confidence statements for the estimate of risk and identify the model components of dominant importance. Uncertainty analyses are required when there is no a priori knowledge about uncertainty in the risk estimate and when there is a chance that the failure to assess uncertainty may affect the selection of wrong options for risk reduction. Uncertainty analyses are effective when they are conducted in an iterative mode. When the uncertainty in the risk estimate is intolerable for decision-making, additional data are acquired for the dominant model components that contribute most to uncertainty. This process is repeated until the level of residual uncertainty can be tolerated. A analytical and numerical methods for error propagation are presented along with methods for identifying the most important contributors to uncertainty. Monte Carlo simulation with either Simple Random Sampling (SRS) or Latin Hypercube Sampling (LHS) is proposed as the most robust method for propagating uncertainty through either simple or complex models. A distinction is made between simulating a stochastically varying assessment endpoint (i.e., the distribution of individual risks in an exposed population) and quantifying uncertainty due to lack of knowledge about a fixed but unknown quantity (e.g., a specific individual, the maximally exposed individual, or the mean, median, or 95%-tile of the distribution of exposed individuals). Emphasis is placed on the need for subjective judgement to quantify uncertainty when relevant data are absent or incomplete

Health risk assessment of exposure to ionizing radiation

International Nuclear Information System (INIS)

Ogata, Hiromitsu

2011-01-01

Risk assessment is an essential process for evaluating the human health effects of exposure to ionizing radiation and for determining acceptable levels of exposure. There are two major components of radiation risk assessment: a measure of exposure level and a measure of disease occurrence. For quantitative estimation of health risks, it is important to evaluate the association between exposure and disease occurrence using epidemiological or experimental data. In these approaches, statistical risk models are used particularly for estimating cancer risks related to exposure to low levels of radiation. This paper presents a summary of basic models and methods of risk assessment for studying exposure-risk relationships. Moreover, quantitative risk estimates are subject to several sources of uncertainty due to inherent limitations in risk assessment studies. This paper also discusses the limitations of radiation risk assessment. (author)

Sovereign default risk assessment

NARCIS (Netherlands)

Rijken, H.A.; Altman, E.I.

2013-01-01

We propose a new approach toward assessing sovereign risk by examining rigorously the health and aggregate default risk of a nation's private corporate sector. Models can be utilised to measure the probability of default of the non-financial sector cumulatively for five years, both as an absolute

Safety analysis, risk assessment, and risk acceptance criteria

International Nuclear Information System (INIS)

Jamali, K.

1997-01-01

This paper discusses a number of topics that relate safety analysis as documented in the Department of Energy (DOE) safety analysis reports (SARs), probabilistic risk assessments (PRA) as characterized primarily in the context of the techniques that have assumed some level of formality in commercial nuclear power plant applications, and risk acceptance criteria as an outgrowth of PRA applications. DOE SARs of interest are those that are prepared for DOE facilities under DOE Order 5480.23 and the implementing guidance in DOE STD-3009-94. It must be noted that the primary area of application for DOE STD-3009 is existing DOE facilities and that certain modifications of the STD-3009 approach are necessary in SARs for new facilities. Moreover, it is the hazard analysis (HA) and accident analysis (AA) portions of these SARs that are relevant to the present discussions. Although PRAs can be qualitative in nature, PRA as used in this paper refers more generally to all quantitative risk assessments and their underlying methods. HA as used in this paper refers more generally to all qualitative risk assessments and their underlying methods that have been in use in hazardous facilities other than nuclear power plants. This discussion includes both quantitative and qualitative risk assessment methods. PRA has been used, improved, developed, and refined since the Reactor Safety Study (WASH-1400) was published in 1975 by the Nuclear Regulatory Commission (NRC). Much debate has ensued since WASH-1400 on exactly what the role of PRA should be in plant design, reactor licensing, 'ensuring' plant and process safety, and a large number of other decisions that must be made for potentially hazardous activities. Of particular interest in this area is whether the risks quantified using PRA should be compared with numerical risk acceptance criteria (RACs) to determine whether a facility is 'safe.' Use of RACs requires quantitative estimates of consequence frequency and magnitude

PRECIS -- A probabilistic risk assessment system

International Nuclear Information System (INIS)

Peterson, D.M.; Knowlton, R.G. Jr.

1996-01-01

A series of computer tools has been developed to conduct the exposure assessment and risk characterization phases of human health risk assessments within a probabilistic framework. The tools are collectively referred to as the Probabilistic Risk Evaluation and Characterization Investigation System (PRECIS). With this system, a risk assessor can calculate the doses and risks associated with multiple environmental and exposure pathways, for both chemicals and radioactive contaminants. Exposure assessment models in the system account for transport of contaminants to receptor points from a source zone originating in unsaturated soils above the water table. In addition to performing calculations of dose and risk based on initial concentrations, PRECIS can also be used in an inverse manner to compute soil concentrations in the source area that must not be exceeded if prescribed limits on dose or risk are to be met. Such soil contaminant levels, referred to as soil guidelines, are computed for both single contaminants and chemical mixtures and can be used as action levels or cleanup levels. Probabilistic estimates of risk, dose and soil guidelines are derived using Monte Carlo techniques

Risk assessment of soil contamination criteria

International Nuclear Information System (INIS)

King, C.M.; Marter, W.L.; Montaque, D.F.; Holton, G.A.

1987-06-01

Criteria have been developed to select radioactive and nonradioactive contaminants at waste sites detailed analysis and risk assessment. These criteria were based on soil and water quality guidelines developed by various government agencies to determine if the criteria were appropriate. We performed a risk assessment of a hypothetical site which contained radioactive and nonradioactive contaminants at levels equal to the criteria values. Risks to the public from atmospheric, surface water, and groundwater exposure pathways were examined. Health risks to the public from atmospheric releases of radioactive and nonradioactive materials from a waste at soil criteria contamination levels are low. Health risks to the maximally exposed individual to chemical carcinogens are considerably below traditional EPA action levels. And health risks to the maximally exposed individual to atmospherically released radioactive contaminants is 1.88 x 10 -7 , more than a factor of 5 less than 10 -6 . Based on our atmospheric exposure pathways analysis and risk assessment, the applied soil criteria are appropriate for screening out unimportant risk contributors to human health from atmospheric exposure pathways. 13 refs., 3 figs., 7 tabs

Modeling individual movement decisions of brown hare (Lepus europaeus) as a key concept for realistic spatial behavior and exposure: A population model for landscape-level risk assessment.

Science.gov (United States)

Kleinmann, Joachim U; Wang, Magnus

2017-09-01

Spatial behavior is of crucial importance for the risk assessment of pesticides and for the assessment of effects of agricultural practice or multiple stressors, because it determines field use, exposition, and recovery. Recently, population models have increasingly been used to understand the mechanisms driving risk and recovery or to conduct landscape-level risk assessments. To include spatial behavior appropriately in population models for use in risk assessments, a new method, "probabilistic walk," was developed, which simulates the detailed daily movement of individuals by taking into account food resources, vegetation cover, and the presence of conspecifics. At each movement step, animals decide where to move next based on probabilities being determined from this information. The model was parameterized to simulate populations of brown hares (Lepus europaeus). A detailed validation of the model demonstrated that it can realistically reproduce various natural patterns of brown hare ecology and behavior. Simulated proportions of time animals spent in fields (PT values) were also comparable to field observations. It is shown that these important parameters for the risk assessment may, however, vary in different landscapes. The results demonstrate the value of using population models to reduce uncertainties in risk assessment and to better understand which factors determine risk in a landscape context. Environ Toxicol Chem 2017;36:2299-2307. © 2017 SETAC. © 2017 SETAC.

Risk assessment for transport operations

International Nuclear Information System (INIS)

Appleton, P.R.; Miles, J.C.

1990-01-01

The world-wide safety of the transport of radioactive material is based on the IAEA Transport Regulations. Risk assessment can provide quantitative data to help in the demonstration, understanding and improvement of the effectiveness of the Regulations in assuring safety. In this Paper the methodology, data and computer codes necessary and available for transport risk assessment are reviewed. Notable examples of assessments carried out over the past 15 years are briefly described along with current research, and the benefits and limitations of the techniques are discussed. (author)

Assessing Extinction Risk: Integrating Genetic Information

Directory of Open Access Journals (Sweden)

Jason Dunham

1999-06-01

Full Text Available Risks of population extinction have been estimated using a variety of methods incorporating information from different spatial and temporal scales. We briefly consider how several broad classes of extinction risk assessments, including population viability analysis, incidence functions, and ranking methods integrate information on different temporal and spatial scales. In many circumstances, data from surveys of neutral genetic variability within, and among, populations can provide information useful for assessing extinction risk. Patterns of genetic variability resulting from past and present ecological and demographic events, can indicate risks of extinction that are otherwise difficult to infer from ecological and demographic analyses alone. We provide examples of how patterns of neutral genetic variability, both within, and among populations, can be used to corroborate and complement extinction risk assessments.

Risk assessment of metal vapor arcing

Science.gov (United States)

Hill, Monika C. (Inventor); Leidecker, Henning W. (Inventor)

2009-01-01

A method for assessing metal vapor arcing risk for a component is provided. The method comprises acquiring a current variable value associated with an operation of the component; comparing the current variable value with a threshold value for the variable; evaluating compared variable data to determine the metal vapor arcing risk in the component; and generating a risk assessment status for the component.

Bimodal fuzzy analytic hierarchy process (BFAHP) for coronary heart disease risk assessment.

Science.gov (United States)

Sabahi, Farnaz

2018-04-04

Rooted deeply in medical multiple criteria decision-making (MCDM), risk assessment is very important especially when applied to the risk of being affected by deadly diseases such as coronary heart disease (CHD). CHD risk assessment is a stochastic, uncertain, and highly dynamic process influenced by various known and unknown variables. In recent years, there has been a great interest in fuzzy analytic hierarchy process (FAHP), a popular methodology for dealing with uncertainty in MCDM. This paper proposes a new FAHP, bimodal fuzzy analytic hierarchy process (BFAHP) that augments two aspects of knowledge, probability and validity, to fuzzy numbers to better deal with uncertainty. In BFAHP, fuzzy validity is computed by aggregating the validities of relevant risk factors based on expert knowledge and collective intelligence. By considering both soft and statistical data, we compute the fuzzy probability of risk factors using the Bayesian formulation. In BFAHP approach, these fuzzy validities and fuzzy probabilities are used to construct a reciprocal comparison matrix. We then aggregate fuzzy probabilities and fuzzy validities in a pairwise manner for each risk factor and each alternative. BFAHP decides about being affected and not being affected by ranking of high and low risks. For evaluation, the proposed approach is applied to the risk of being affected by CHD using a real dataset of 152 patients of Iranian hospitals. Simulation results confirm that adding validity in a fuzzy manner can accrue more confidence of results and clinically useful especially in the face of incomplete information when compared with actual results. Applying the proposed BFAHP on CHD risk assessment of the dataset, it yields high accuracy rate above 85% for correct prediction. In addition, this paper recognizes that the risk factors of diastolic blood pressure in men and high-density lipoprotein in women are more important in CHD than other risk factors. Copyright © 2018 Elsevier Inc. All

Modeling number of bacteria per food unit in comparison to bacterial concentration in quantitative risk assessment: impact on risk estimates.

Science.gov (United States)

Pouillot, Régis; Chen, Yuhuan; Hoelzer, Karin

2015-02-01

When developing quantitative risk assessment models, a fundamental consideration for risk assessors is to decide whether to evaluate changes in bacterial levels in terms of concentrations or in terms of bacterial numbers. Although modeling bacteria in terms of integer numbers may be regarded as a more intuitive and rigorous choice, modeling bacterial concentrations is more popular as it is generally less mathematically complex. We tested three different modeling approaches in a simulation study. The first approach considered bacterial concentrations; the second considered the number of bacteria in contaminated units, and the third considered the expected number of bacteria in contaminated units. Simulation results indicate that modeling concentrations tends to overestimate risk compared to modeling the number of bacteria. A sensitivity analysis using a regression tree suggests that processes which include drastic scenarios consisting of combinations of large bacterial inactivation followed by large bacterial growth frequently lead to a >10-fold overestimation of the average risk when modeling concentrations as opposed to bacterial numbers. Alternatively, the approach of modeling the expected number of bacteria in positive units generates results similar to the second method and is easier to use, thus potentially representing a promising compromise. Published by Elsevier Ltd.

Assessing reservoir operations risk under climate change

Science.gov (United States)

Brekke, L.D.; Maurer, E.P.; Anderson, J.D.; Dettinger, M.D.; Townsley, E.S.; Harrison, A.; Pruitt, T.

2009-01-01

Risk-based planning offers a robust way to identify strategies that permit adaptive water resources management under climate change. This paper presents a flexible methodology for conducting climate change risk assessments involving reservoir operations. Decision makers can apply this methodology to their systems by selecting future periods and risk metrics relevant to their planning questions and by collectively evaluating system impacts relative to an ensemble of climate projection scenarios (weighted or not). This paper shows multiple applications of this methodology in a case study involving California's Central Valley Project and State Water Project systems. Multiple applications were conducted to show how choices made in conducting the risk assessment, choices known as analytical design decisions, can affect assessed risk. Specifically, risk was reanalyzed for every choice combination of two design decisions: (1) whether to assume climate change will influence flood-control constraints on water supply operations (and how), and (2) whether to weight climate change scenarios (and how). Results show that assessed risk would motivate different planning pathways depending on decision-maker attitudes toward risk (e.g., risk neutral versus risk averse). Results also show that assessed risk at a given risk attitude is sensitive to the analytical design choices listed above, with the choice of whether to adjust flood-control rules under climate change having considerably more influence than the choice on whether to weight climate scenarios. Copyright 2009 by the American Geophysical Union.

NASA Human System Risk Assessment Process

Science.gov (United States)

Francisco, D.; Romero, E.

2016-01-01

NASA utilizes an evidence based system to perform risk assessments for the human system for spaceflight missions. The center of this process is the multi-disciplinary Human System Risk Board (HSRB). The HSRB is chartered from the Chief Health and Medical Officer (OCHMO) at NASA Headquarters. The HSRB reviews all human system risks via an established comprehensive risk and configuration management plan based on a project management approach. The HSRB facilitates the integration of human research (terrestrial and spaceflight), medical operations, occupational surveillance, systems engineering and many other disciplines in a comprehensive review of human system risks. The HSRB considers all factors that influence human risk. These factors include pre-mission considerations such as screening criteria, training, age, sex, and physiological condition. In mission factors such as available countermeasures, mission duration and location and post mission factors such as time to return to baseline (reconditioning), post mission health screening, and available treatments. All of the factors influence the total risk assessment for each human risk. The HSRB performed a comprehensive review of all potential inflight medical conditions and events and over the course of several reviews consolidated the number of human system risks to 30, where the greatest emphasis is placed for investing program dollars for risk mitigation. The HSRB considers all available evidence from human research and, medical operations and occupational surveillance in assessing the risks for appropriate mitigation and future work. All applicable DRMs (low earth orbit for 6 and 12 months, deep space for 30 days and 1 year, a lunar mission for 1 year, and a planetary mission for 3 years) are considered as human system risks are modified by the hazards associated with space flight such as microgravity, exposure to radiation, distance from the earth, isolation and a closed environment. Each risk has a summary

Risk assessment research and technology assessment

International Nuclear Information System (INIS)

Albach, H.; Schade, D.; Sinn, H.

1991-01-01

The concepts and approaches for technology assessment, the targets and scientific principles, as well as recognizable deficits and recommendations concerning purposeful strategies for the promotion of this research field require a dialog between those concerned. Conception, deficits, and the necessary measures for risk assessment research and technology assessment were discussed as well as ethical aspects. The problematic nature of using organisms altered through genetic engineering in the open land, traffic and transport, site restoration, nuclear energy, and isotope applications were subjects particularly dealt with. (DG) [de

Assessment of Interpersonal Risk (AIR) in Adults with Learning Disabilities and Challenging Behaviour--Piloting a New Risk Assessment Tool

Science.gov (United States)

Campbell, Martin; McCue, Michael

2013-01-01

A new risk assessment tool, "Assessment of Interpersonal Risk" (AIR), was piloted and evaluated to measure risk factors and compatibility between individuals living in an assessment and treatment unit in one NHS area. The adults with learning disabilities in this unit had severe and enduring mental health problems and/or behaviour that is severely…

The Symbiose project: an integrated framework for performing environmental radiological risk assessment

International Nuclear Information System (INIS)

Gonze, M.A.; Mourlon, C.; Garcia-Sanchez, L.; Beaugelin, K.; Chen, T.; Le Dizes, S.

2004-01-01

Human health and ecological risk assessments usually require the integration of a wide range of environmental data and modelling approaches, with a varying level of detail dependent on the management objectives, the complexity of the site and the level of ignorance about the pollutant behaviour/toxicity. Like most scientists and assessors did it recently, we recognized the need for developing comprehensive, integrated and flexible approaches to risk assessment. To meet these needs, IRSN launched the Symbiose project (2002-2006) which aims first, at designing a framework for integrating and managing data, methods and knowledge of some relevance in radiological risk to humans/biota assessment studies, and second, at implementing this framework in an information management, modelling and calculation platform. Feasibility developments (currently completed) led to the specification of a fully integrated, object-oriented and hierarchical approach for describing the fate, transport and effect of radionuclides in spatially-distributed environmental systems. This innovative approach has then been implemented in a platform prototype, main components of which are a user-friendly and modular simulation environment (e.g. using GoldSim toolbox), and a hierarchical object-oriented biosphere database. Both conceptual and technical developments will be presented here. (author)

The influence of spatial resolution on human health risk co-benefit estimates for global climate policy assessments.

Science.gov (United States)

Shih, Hsiu-Ching; Crawford-Brown, Douglas; Ma, Hwong-wen

2015-03-15

Assessment of the ability of climate policies to produce desired improvements in public health through co-benefits of air pollution reduction can consume resources in both time and research funds. These resources increase significantly as the spatial resolution of models increases. In addition, the level of spatial detail available in macroeconomic models at the heart of climate policy assessments is much lower than that available in traditional human health risk modeling. It is therefore important to determine whether increasing spatial resolution considerably affects risk-based decisions; which kinds of decisions might be affected; and under what conditions they will be affected. Human health risk co-benefits from carbon emissions reductions that bring about concurrent reductions in Particulate Matter (PM10) emissions is therefore examined here at four levels of spatial resolution (Uniform Nation, Uniform Region, Uniform County/city, Health Risk Assessment) in a case study of Taiwan as one of the geographic regions of a global macroeceonomic model, with results that are representative of small, industrialized nations within that global model. A metric of human health risk mortality (YOLL, years of life lost in life expectancy) is compared under assessments ranging from a "uniform simulation" in which there is no spatial resolution of changes in ambient air concentration under a policy to a "highly spatially resolved simulation" (called here Health Risk Assessment). PM10 is chosen in this study as the indicator of air pollution for which risks are assessed due to its significance as a co-benefit of carbon emissions reductions within climate mitigation policy. For the policy examined, the four estimates of mortality in the entirety of Taiwan are 747 YOLL, 834 YOLL, 984 YOLL and 916 YOLL, under Uniform Taiwan, Uniform Region, Uniform County and Health Risk Assessment respectively; or differences of 18%, 9%, 7% if the HRA methodology is taken as the baseline. While

Significance of earthquake risk in nuclear power plant probabilistic risk assessments

International Nuclear Information System (INIS)

Sues, R.H.; Amico, P.J.; Campbell, R.D.

1990-01-01

During the last eight years, approximately 25 utility-sponsored probabilistic risk assessments (PRAs) have been conducted for US nuclear reactors. Of these, ten have been published, seven of which have included complete seismic risk assessment. The results of the seven published PRAs are reviewed here in order to ascertain the significance of the risk due to earthquake initiating events. While PRA methodology has been in a state of development over the past seven years, and the results are subject to interpretation (as discussed in the paper), from the review conducted it is clear that earthquake-induced initiating events are important risk contributors. It is concluded that earthquake initiating events should not be dismissed, a priori, in any nuclear plant risk assessment. (orig.)

Photosynthesis and oxidative stress in the restinga plant species Eugenia uniflora L. exposed to simulated acid rain and iron ore dust deposition: Potential use in environmental risk assessment

Energy Technology Data Exchange (ETDEWEB)

Rust Neves, Natalia; Oliva, Marco Antonio; Cruz Centeno, Danilo da; Costa, Alan Carlos; Ferreira Ribas, Rogerio [Departamento de Biologia Vegetal, Universidade Federal de Vicosa, Av. PH Rolfs, Campus, Vicosa, Minas Gerais, 36570-000 (Brazil); Gusmao Pereira, Eduardo, E-mail: egpereira@gmail.com [Departamento de Biologia Vegetal, Universidade Federal de Vicosa, Av. PH Rolfs, Campus, Vicosa, Minas Gerais, 36570-000 (Brazil)

2009-06-01

The Brazilian sandy coastal plain named restinga is frequently subjected to particulate and gaseous emissions from iron ore factories. These gases may come into contact with atmospheric moisture and produce acid rain. The effects of the acid rain on vegetation, combined with iron excess in the soil, can lead to the disappearance of sensitive species and decrease restinga biodiversity. The effects of iron ore dust deposition and simulated acid rain on photosynthesis and on antioxidant enzymes were investigated in Eugenia uniflora, a representative shrub species of the restinga. This study aimed to determine the possible utility of this species in environmental risk assessment. After the application of iron ore dust as iron solid particulate matter (SPM{sub Fe}) and simulated acid rain (pH 3.1), the 18-month old plants displayed brown spots and necrosis, typical symptoms of iron toxicity and injuries caused by acid rain, respectively. The acidity of the rain intensified leaf iron accumulation, which reached phytotoxic levels, mainly in plants exposed to iron ore dust. These plants showed the lowest values for net photosynthesis, stomatal conductance, transpiration, chlorophyll a content and electron transport rate through photosystem II (PSII). Catalase and superoxide dismutase activities were decreased by simulated acid rain. Peroxidase activity and membrane injury increased following exposure to acid rain and simultaneous SPM{sub Fe} application. Eugenia uniflora exhibited impaired photosynthetic and antioxidative metabolism in response to combined iron and acid rain stresses. This species could become a valuable tool in environmental risk assessment in restinga areas near iron ore pelletizing factories. Non-invasive evaluations of visual injuries, photosynthesis and chlorophyll a fluorescence, as well as invasive biochemical analysis could be used as markers.

Photosynthesis and oxidative stress in the restinga plant species Eugenia uniflora L. exposed to simulated acid rain and iron ore dust deposition: Potential use in environmental risk assessment

International Nuclear Information System (INIS)

Rust Neves, Natalia; Oliva, Marco Antonio; Cruz Centeno, Danilo da; Costa, Alan Carlos; Ferreira Ribas, Rogerio; Gusmao Pereira, Eduardo

2009-01-01

The Brazilian sandy coastal plain named restinga is frequently subjected to particulate and gaseous emissions from iron ore factories. These gases may come into contact with atmospheric moisture and produce acid rain. The effects of the acid rain on vegetation, combined with iron excess in the soil, can lead to the disappearance of sensitive species and decrease restinga biodiversity. The effects of iron ore dust deposition and simulated acid rain on photosynthesis and on antioxidant enzymes were investigated in Eugenia uniflora, a representative shrub species of the restinga. This study aimed to determine the possible utility of this species in environmental risk assessment. After the application of iron ore dust as iron solid particulate matter (SPM Fe ) and simulated acid rain (pH 3.1), the 18-month old plants displayed brown spots and necrosis, typical symptoms of iron toxicity and injuries caused by acid rain, respectively. The acidity of the rain intensified leaf iron accumulation, which reached phytotoxic levels, mainly in plants exposed to iron ore dust. These plants showed the lowest values for net photosynthesis, stomatal conductance, transpiration, chlorophyll a content and electron transport rate through photosystem II (PSII). Catalase and superoxide dismutase activities were decreased by simulated acid rain. Peroxidase activity and membrane injury increased following exposure to acid rain and simultaneous SPM Fe application. Eugenia uniflora exhibited impaired photosynthetic and antioxidative metabolism in response to combined iron and acid rain stresses. This species could become a valuable tool in environmental risk assessment in restinga areas near iron ore pelletizing factories. Non-invasive evaluations of visual injuries, photosynthesis and chlorophyll a fluorescence, as well as invasive biochemical analysis could be used as markers.

Chemical Risk Assessment: Traditional vs Public Health ...

Science.gov (United States)

Preventing adverse health impacts from exposures to environmental chemicals is fundamental to protecting individual and public health. When done efficiently and properly, chemical risk assessment enables risk management actions that minimize the incidence and impacts of environmentally-induced diseases related to chemical exposure. However, traditional chemical risk assessment is faced with multiple challenges with respect to predicting and preventing disease in human populations, and epidemiological studies increasingly report observations of adverse health effects at exposure levels predicted from animal studies to be safe for humans. This discordance reinforces concerns about the adequacy of contemporary risk assessment practices (Birnbaum, Burke, & Jones, 2016) for protecting public health. It is becoming clear that to protect public health more effectively, future risk assessments will need to use the full range of available data, draw on innovative methods to integrate diverse data streams, and consider health endpoints that also reflect the range of subtle effects and morbidities observed in human populations. Given these factors, there is a need to reframe chemical risk assessment to be more clearly aligned with the public health goal of minimizing environmental exposures associated with disease. Preventing adverse health impacts from exposures to environmental chemicals is fundamental to protecting individual and public health. Chemical risk assessments

Risk-assessment methodology for fast breeder reactors

International Nuclear Information System (INIS)

Ott, K.O.

1976-04-01

The methods applied or proposed for risk assessment of nuclear reactors are reviewed, particularly with respect to their applicability for risk assessment of future commercial fast breeder reactors. All methods are based on the calculation of accident consequences for relatively few accident scenarios. The role and general impact of uncertainties in fast-reactor accident analysis are discussed. The discussion shows the need for improvement of the methodology. A generalized and improved risk-assessment methodology is outlined and proposed (accident-spectra-progression approach). The generalization consists primarily of an explicit treatment of uncertainties throughout the accident progression. The results of this method are obtained in form of consequence distributions. The width and shape of the distributions depend in part on the superposition of the uncertainties. The first moment of the consequence distribution gives an improved prediction of the ''average'' consequence. The higher-consequence moments can be used for consideration of risk aversion. The assessment of the risk of one or a certain number of nuclear reactors can only provide an ''isolated'' risk assessment. The general problem of safety risk assessment and its relation to public acceptance of certain modes of power production is a much broader problem area, which is also discussed

The evolution of violence risk assessment.

Science.gov (United States)

Monahan, John; Skeem, Jennifer L

2014-10-01

Many instruments have been published in recent years to improve the ability of mental health clinicians to estimate the likelihood that an individual will behave violently toward others. Increasingly, these instruments are being applied in response to laws that require specialized risk assessments. In this review, we present a framework that goes beyond the "clinical" and "actuarial" dichotomy to describe a continuum of structured approaches to risk assessment. Despite differences among them, there is little evidence that one instrument predicts violence better than another. We believe that these group-based instruments are useful for assessing an individual's risk, and that the instrument should be chosen based on the purpose of the assessment.

Environmental Comparative Risk Assessment: A Case Study

International Nuclear Information System (INIS)

Ali, M.M.

2007-01-01

Health and environmental impacts associated with energy production and industrial activities as well as food production and agricultural activities have had great concern in the last decades. Early activities emerged in late 80s of the last century through an Inter- Agency project (lAEA, UNDY, WHO, ... ) on the comparative risk assessment from energy systems and industrial complexes. A work-shop on Risk Assessment and Management in large industrial areas was held in Alexandria Egypt on 20-33 Det 1993, sponsored by IAEA. Several conferences, experts work groups and workshops were held there of Recent trends in determining risks are: 1. Use of probabilistic risk assessment approach to identify hazardous activities and accident scenario. 2. development of data base on failure probabilities and appropriate physical models. 3. Development of related directives and regulations and criteria Comparative risk assessment case study as a tool for comparing risk is emphasized Criteria of exposure to human and ecological risks are addressed

Assessment of the Fire Risk Levels in an Office Building and a Nightclub with Prescriptive Designs

DEFF Research Database (Denmark)

Yilmaz, D.; Steffensen, F.B.; Jomaas, Grunde

2014-01-01

A comparison of the risk level of an office building and a nightclub with code compliant prescriptive designs was conducted in order to evaluate whether an uniform safety level of the two occupancy types can be established. A risk assessment method using Monte Carlo simulations and 1- and 2-zone......-movement time and the movement time were adjusted for the required safe egress time (RSET) of the nightclub. The number of simulations required in order to obtain reliable results was considered sufficient at 20,000. The comparison of the risk profiles of the nightclub and the office building showed significant...... difference in risk levels, with that of the nightclub being substantially higher. The higher risk level in the nightclub is caused by a relatively fast mean value of the fire growth rate and the high number of occupants. Hence, the requirements in the prescriptive code do not ensure a similar safety level...

Risk assessment approach for Rokkasho reprocessing plant

International Nuclear Information System (INIS)

Ootou, Y.; Tamauchi, Y.; Hayashi, Y.; Takebe, K.; Miyata, T.

2006-01-01

Full text: It is desirable that the operation and maintenance of Rokkasho Reprocessing Plant (RRP) be established and conducted with maximum effectiveness and efficiency, making the best use of risk information to help the plant achieve further enhanced safety. Risk assessment is applied for RRP, and upgraded risk information is established. In the basic design phase, the potential incidents and accidents that might occur in the plant were identified systematically and exhaustively adopting the HAZOP method. After screening the potential for occurrence, the design basis accidents (DBAs) were identified and it was confirmed that the plant would not put the general public at risk of significant radiation exposure in the case of such accidents, even when assuming the single failure of dynamic apparatus in the prevention and mitigation systems. To support the deterministic safety assessment mentioned above, the risk assessment was conducted during the basic design phase. Of the DBAs and out-of-design basis accidents excluded from DBAs because of extremely rare occurrence possibilities, the risk assessment was conducted for such accidents which might cause relatively high consequence for the general public. The risk assessment was conducted using the PSA method generally used for nuclear power plants. After that, a review of the occurrence frequency assessment for some of the accidents was made, taking into account information relating to detailed design and operation procedures. Typical examples are a loss of the hydrogen scavenging function in the plutonium solution tank and a loss of cooling capability in the high-active liquid waste storage tank. The occurrence frequency for a loss of the hydrogen scavenging function was less than 10 -5 /year. The occurrence frequency for a loss of cooling capability was less than 10 -7 /year. In addition, an importance assessment (FV index, Risk Achievement Worth) was conducted, such as a contribution to the occurrence frequency

The Risk Assessment at the Workplace of Assembly Operation

Directory of Open Access Journals (Sweden)

Marek Burda

2014-01-01

Full Text Available Risk Assessment Process by FMEA method involve hazard identification, risk assessment and risk control processes and their input is fundamental to a successful EH&S system. This Risk assessment tool follows the general process and requirements of the Health and Safety Risk Assessment Procedure.

Wearable technology and ECG processing for fall risk assessment, prevention and detection.

Science.gov (United States)

Melillo, Paolo; Castaldo, Rossana; Sannino, Giovanna; Orrico, Ada; de Pietro, Giuseppe; Pecchia, Leandro

2015-01-01

Falls represent one of the most common causes of injury-related morbidity and mortality in later life. Subjects with cardiovascular disorders (e.g., related to autonomic dysfunctions and postural hypotension) are at higher risk of falling. Autonomic dysfunctions increasing the risk of falling in the short and mid-term could be assessed by Heart Rate Variability (HRV) extracted by electrocardiograph (ECG). We developed three trials for assessing the usefulness of ECG monitoring using wearable devices for: risk assessment of falling in the next few weeks; prevention of imminent falls due to standing hypotension; and fall detection. Statistical and data-mining methods are adopted to develop classification and regression models, validated with the cross-validation approach. The first classifier based on HRV features enabled to identify future fallers among hypertensive patients with an accuracy of 72% (sensitivity: 51.1%, specificity: 80.2%). The regression model to predict falls due to orthostatic dropdown from HRV recorded before standing achieved an overall accuracy of 80% (sensitivity: 92%, specificity: 90%). Finally, the classifier to detect simulated falls using ECG achieved an accuracy of 77.3% (sensitivity: 81.8%, specificity: 72.7%). The evidence from these three studies showed that ECG monitoring and processing could achieve satisfactory performances compared to other system for risk assessment, fall prevention and detection. This is interesting as differently from other technologies actually employed to prevent falls, ECG is recommended for many other pathologies of later life and is more accepted by senior citizens.

Comparison of landslide hazard and risk assessment practices in Europe

Science.gov (United States)

Corominas, J.; Mavrouli, O.

2012-04-01

An overview is made of the landslide hazard and risk assessment practices that are officially promoted or applied in Europe by administration offices, geological surveys, and decision makers (recommendations, regulations and codes). The reported countries are: Andorra, Austria, France, Italy (selected river basins), Romania, Spain (Catalonia), Switzerland and United Kingdom. The objective here was to compare the different practices for hazard and risk evaluation with respect to the official policies, the methodologies used (qualitative and quantitative), the provided outputs and their contents, and the terminology and map symbols used. The main observations made are illustrated with examples and the possibility of harmonization of the policies and the application of common practices to bridge the existing gaps is discussed. Some of the conclusions reached include the following: zoning maps are legally binding for public administrators and land owners only in some cases and generally when referring to site-specific or local scales rather than regional or national ones; so far, information is mainly provided on landslide susceptibility and hazard and risk assessment is performed only in a few countries; there is a variation in the use of scales between countries; the classification criteria for landslide types and mechanisms present large diversity even within the same country (in some cases no landslide mechanisms are specified while in others there is an exhaustive list); the techniques to obtain input data for the landslide inventory and susceptibility maps vary from basic to sophisticated, resulting in various levels of data quality and quantity; the procedures followed for hazard and risk assessment include analytical procedures supported by computer simulation, weighted-indicators, expert judgment and field survey-based, or a combination of all; there is an important variation between hazard and risk matrices with respect to the used parameters, the thresholds

Research into specific risk assessment in project financing

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