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Hydrogen Quantitative Risk Assessment

Muna, Alice B.; Ehrhart, Brian D.; Hecht, Ethan S.; Bran Anleu, Gabriela A.; Blaylock, Myra L.; LaFleur, Chris B.

DOE has identified consistent safety, codes, and standards as a critical need for the deployment of hydrogen technologies, with key barriers related to the availability and implementation of technical information in the development of regulations, codes, and standards. Advances in codes and standards have been enabled by risk-informed approaches to create and implement revisions to codes, such as National Fire Protection Association (NFPA) 2, NFPA 55, and International Organization for Standardization (ISO) Technical Specification (TS)-19880-1. This project provides the technical basis for these revisions, enabling the assessment of the safety of hydrogen fuel cell systems and infrastructure using QRA and physics-based models of hydrogen behavior. The risk and behavior tools that are developed in this project are motivated by, shared directly with, and used by the committees revising relevant codes and standards, thus forming the scientific basis to ensure that code requirements are consistent, logical, and defensible.

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Analyses in Support of Risk-Informed Natural Gas Vehicle Maintenance Facility Codes and Standards: Phase II

Blaylock, Myra L.; LaFleur, Chris B.; Muna, Alice B.; Ehrhart, Brian D.

Safety standards development for maintenance facilities of liquid and compressed natural gas fueled vehicles is required to ensure proper facility design and operating procedures. Standard development organizations are utilizing risk-informed concepts to develop natural gas vehicle (NGV) codes and standards so that maintenance facilities meet acceptable risk levels. The present report summarizes Phase II work for existing NGV repair facility code requirements and highlights inconsistencies that need quantitative analysis into their effectiveness. A Hazardous and Operability study was performed to identify key scenarios of interest using risk ranking. Detailed simulations and modeling were performed to estimate the location and behavior of natural gas releases based on these scenarios. Specific code conflicts were identified, and ineffective code requirements were highlighted and resolutions proposed. These include ventilation rate basis on area or volume, as well as a ceiling offset which seems ineffective at protecting against flammable gas concentrations. ACKNOWLEDGEMENTS The authors gratefully acknowledge Bill Houf (SNL -- Retired) for his assistance with the set-up and post-processing of the numerical simulations. The authors also acknowledge Doug Horne (retired) for his helpful discussions. We would also like to acknowledge the support from the Clean Cities program of DOE's Vehicle Technology Office.

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HyRAM V1.1 User Guide

Sena, Ethan A.; Ehrhart, Brian D.; Muna, Alice B.

Hydrogen Risk Assessment Models (HyRAM) is a software toolkit that provides a basis for quantitative risk assessment and consequence modeling for hydrogen infrastructure and transportation systems. HyRAM integrates validated, analytical models of hydrogen behavior, statistics, and a standardized QRA approach to generate useful, repeatable data for the safety analysis of various hydrogen systems. HyRAM is a software developed by Sandia National Laboratories for the U.S. Department of Energy. This document demonstrates how to use HyRAM to recreate a hydrogen system and obtain relevant data regarding potential risk. Specific examples are utilized throughout this document, providing detailed tutorials of HyRAM features with respect to hydrogen system safety analysis and risk assessment.

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Results 26–50 of 86
Results 26–50 of 86