Risk-informed process and tools for permitting hydrogen fueling stations

Abstract

The permitting process for hydrogen fueling stations varies from country to country. However, a common step in the permitting process is the demonstration that the proposed fueling station meets certain safety requirements. Currently, many permitting authorities rely on compliance with wellknown codes and standards as a means to permit a facility. Current codes and standards for hydrogen facilities require certain safety features, specify equipment made of material suitable for hydrogen environment, and include separation or safety distances. Thus, compliance with the code and standard requirements is widely accepted as evidence of a safe design. However, to ensure that a hydrogen facility is indeed safe, the code and standard requirements should be identified using a risk-informed process that utilizes an acceptable level of risk. When compliance with one or more code or standard requirements is not possible, a n evaluation of the risk associated with the exemptions to the requirements should be understood and conveyed to the Authority Having Jurisdiction (AHJ). Establishment of a consistent risk assessment toolset and associated data is essential to performing these risk evaluations. This paper describes an approach for risk-informing the permitting process for hydrogen fueling stations that relies primarily on the establishment of risk-informed codes and standards. The proposed risk-informed process begins with the establishment of acceptable risk criteria associated with the operation of hydrogen fueling stations. Using accepted Quantitative Risk Assessment (QRA) techniques and the established risk criteria, the minimum code and standard requirements necessary to ensure the safe operation of hydrogen facilities can be identified. Riskinformed permitting processes exist in some countries and are being developed in others. To facilitate consistent risk-informed approaches, the participants in the International Energy Agency (IEA) Task 19 on hydrogen safety are working to identify acceptable risk criteria, QRA models, and supporting data 1 .

Ignitability and mixing of underexpanded hydrogen jets

“…A prerequisite for large-scale infrastructure development is the implementation of science based safety codes and standards that rely on effective quantitative risk analysis (QRA) tools [1]. Validated consequence models for planned and unintended hydrogen release ignitable boundaries are a necessary QRA requirement needed to establish suitable separation distances and risk mitigation features.…”

Early-stage quantitative risk assessment to support development of codes and standard requirements for indoor fueling of hydrogen vehicles.

“…This is accomplished using available software packages such as SAPHIRE 4 or by developing programs (e.g., in Matlab).…”

“…QRA for indoor fueling The QRA process provides important insights, but these insights are only as detailed and only as reliable as the information used to produce the analysis. LaChance et al [4] described the necessary features for a comprehensive QRA, and Pasman [37] has identified several QRA gaps that are relevant to the hydrogen infrastructure. In this section, we discuss the gaps that are relevant to indoor fueling.…”

“…A risk-informed process can help establish the baseline design and operational requirements for hydrogen fueling stations. In previous work, LaChance et al [4] developed a framework for risk-informing the process of permitting hydrogen fueling stations; this includes establishing riskinformed hydrogen codes and standards. Using risk-informed codes and standards ensures that all permitted facilities have a basic design that ensures a minimum acceptable level of safety under intended operating conditions.…”

Accident modelling and safety measure design of a hydrogen station

“…To reduce the risk, reliable risk analysis methodology is required so that appropriate control measures can be planned and required safety standards can be established. This is particularly important especially when the population at large is involved such as in the case of hydrogen stations [4].…”