Current Engineering Models and Capabilities in the Vulnerability Assessment and Protection Option (VAPO) Software

Nichols, J. F.; Doyle, Glynda Rees

doi:10.1061/9780784413357.017

Cited by 3 publications

(2 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hazards for toxic CDCs are through inhalation, whereas atmospheric (outdoor) dispersion of a toxic cloud is modeled using the Second-Order Closure Integrated Puff (SCIPUFF) model (Sykes et al, 2016) and indoor concentrations are calculated based on outdoor concentra-tions and an air exchange rate of 0.75 air changes per hour. 5 Hazards for flammable and explosive CDCs are through overpressure-induced blast effects, whereas the outdoor hazards are based on the U.S. Department of Defense's standard trinitrotoluene (TNT) blast curves (U.S. Department of Defense, 2014) and the indoor hazards are based on the Defense Threat Reduction Agency's Vulnerability Assessment and Protection Option (VAPO) model (Nichols and Doyle, 2014). For all types of CDCs (i.e., toxic, flammable, and explosive), consequence is estimated by mapping fatality zones on the local population distribution as pro- 5 That is, 75 percent of the air inside a building will be exchanged per hour.…”

Section: The Risk Engine In the Cfats Program Risk Tiering Methodologymentioning

confidence: 99%

Risk-Informed Analysis of Transportation Worker Identification Credential Reader Requirements

2022

View full text Add to dashboard Cite

To help it implement the final reader rule entitled "Transportation Worker Identification Credential (TWIC)-Reader Requirements," the U.S. Coast Guard (USCG) asked the Homeland Security Operational Analysis Center (HSOAC) to estimate the population of the Maritime Transportation Security Act-regulated facilities that the rule might affect; develop a transparent, objective risk assessment model for these facilities; and conduct a cost-benefit analysis of the regulation.This report describes our analytical efforts to address the three research areas mentioned above. Because there is no database of Maritime Transportation Security Act-regulated facilities with all the requisite information about certain dangerous cargoes that facilities handle in bulk, we resorted to other data sources, such as the U.S. Environmental Protection Agency's databases, an online survey, and interviews, to estimate the facility population. For the facility risk model, we used the modeling approach for assessing potential consequence included in the risk engine of the Cybersecurity and Infrastructure Security Agency's Chemical Facility Anti-Terrorism Standards (CFATS) program, harmonizing the TWIC and CFATS programs in consequence assessment. Because there was no credible estimate for the probability of a transportation security incident, we used a break-even analysis to assess whether the final reader rule is cost-effective.This research was sponsored by the USCG Office of Standards Evaluation and Development and conducted within the Strategy, Policy, and Operations Program of the HSOAC federally funded research and development center (FFRDC).Risk-Informed Analysis of Transportation Worker Identification Credential Reader Requirements vi S.2. Our ApproachThe overarching principle of our study is transparency and defensibility in support of rulemaking and implementation. To that end, we • used only unclassified and nonproprietary data • applied consistent, reproducible approaches • clearly documented the formulations, assumptions, and limitations of our approaches.For example, because a single comprehensive data source with the requisite information does not exist, we collected and collated facility-level information from multiple unclassified data sources to estimate the population of facilities subject to the reader rule delay. We decided to conduct a consequence-based risk assessment for this study because threat and vulnerability information is typically restricted.Our facility risk model is based on the Cybersecurity and Infrastructure Security Agency's well-known and well-documented Chemical Facility Anti-Terrorism Standards risk engine (Cybersecurity and Infrastructure Security Agency, 2021), whose consequence (in terms of the number of fatalities resulting from a potential CDC release) assessment methodologies are objective (i.e., physics-based and reproducible) and transparent (i.e., with ample documentation). We further developed a facility typology to practically group facilities based on observable attributes, such as CDC quant...

show abstract

Section: The Risk Engine In the Cfats Program Risk Tiering Methodologymentioning

confidence: 99%

Risk-Informed Analysis of Transportation Worker Identification Credential Reader Requirements

2022

View full text Add to dashboard Cite

show abstract

“…The Vulnerability Assessment and Protection Option (VAPO) program as an integrated environment can provide a rapid characterization, analysis and vulnerability assessment for complex urban environments such as landscape sites, buildings and vehicles while using semi-empirical formulas to generate the blast loading (Nichols and Doyle, 2014).…”

Section: Prediction Toolsmentioning

confidence: 99%

Blast wave interaction with structures – An overview

Isaac

Alshammari

Pickering

et al. 2022

International Journal of Protective Structures

View full text Add to dashboard Cite

Blast–obstacle interaction is a complex, multi-faceted problem. Whilst engineering-level tools exist for predicting blast parameters (e.g. peak pressure, impulse and loading duration) in geometrically simple settings, a blast wave is fundamentally altered upon interaction with an object in its path, and hence, the loading parameters are themselves affected. This article presents a comprehensive review of key research in this area. The review is formed of five main parts, each describing: the direct loading of a blast wave on the surface of a finite-sized structure; the modified pressure of the blast wave in the wake region of three main obstacle types – blast walls, obstacles, wall/obstacle hybrids; and finally, a brief description of some methods for predicting loading parameters in such blast–obstacle interaction settings. Key findings relate to the mechanisms governing blast attenuation, for example, diffraction, reflection (diverting away from the target structure), expansion/volume increase, vortex creation/growth, as well as obstacle properties influencing these, such as porosity (blockage ratio), obstacle shape, number of obstacles/rows, arrangement and surface roughness.

show abstract

Quantifying Blast Effects on Constructed Facilities behind Blast Walls

Schuldt

El‐Rayes

2017

J. Perform. Constr. Facil.

View full text Add to dashboard Cite

Current Engineering Models and Capabilities in the Vulnerability Assessment and Protection Option (VAPO) Software

Cited by 3 publications

References 2 publications

Risk-Informed Analysis of Transportation Worker Identification Credential Reader Requirements

Risk-Informed Analysis of Transportation Worker Identification Credential Reader Requirements

Blast wave interaction with structures – An overview

Quantifying Blast Effects on Constructed Facilities behind Blast Walls

Contact Info

Product

Resources

About