Secondary Protection for 70 MPa Fueling - A White Paper from the Hydrogen Safety Panel

Abstract

This document was printed on recycled paper. Executive SummaryIn developing a 70 megapascal (MPa) fueling infrastructure, it is critical to ensure that a vehicle equipped with a lower service pressure fuel tank is never filled from a 70 MPa fueling source. Filling of a lower service pressure vehicle at a 70 MPa fueling source is likely to result in a catastrophic event with severe injuries or fatalities. The Hydrogen Safety Panel recommends that DOE undertake a two-step process to address this issue:1. Perform an independent risk analysis of a 70MPa dispenser filling a lower pressure vehicle tank and develop different approaches for prevention and mitigation to meet an acceptable level of safety. Cost effectiveness, reliability, advantages and disadvantages are among the factors that should be evaluated for each approach considered.2. Until such time as this analysis is complete and any recommended actions implemented, communicate the potential risk to responsible parties and strongly encourage those parties to add a secondary layer of protection to the existing system of mechanically non-interchangeable nozzles/receptacles. This will reduce the probability of a pressure mismatch during this developmental phase for hydrogen fuel cell vehicles and infrastructure. This step can be reassessed after further analysis is completed and the need and effectiveness of secondary protection methods are evaluated.This paper provides background discussion of the problem, current safety systems and strategy and examples of potential future solutions to support the above recommendations.

SNANA: A Public Software Package for Supernova Analysis

“…The SNANA software package was originally developed and used for the analysis of the SDSS-II SN sample (Frieman et al 2008;Kessler et al 2009), but the need to plan for future SN surveys, such as the Dark Energy Survey (DES 10 ) and Large Synoptic Survey Telescope (LSST 11 ), led to a publicly available package. Additional motivation for public-use software is described in Weiner et al (2009). This paper describes the capabilities of SNANA, which are rapidly evolving with the needs of larger SN samples.…”