Hazardous Areas Impact Mitigation (HAIM) Phase 3
Abstract
NIA_NGN_346 demonstrated that in a 100% hydrogen conversion scenario, hazardous areas of some above ground installations (AGIs) on the network would extend far beyond their current site boundaries. The Hazardous Area Impact Mitigation (HAIM) work programme was set up to investigate these findings and develop potential mitigations. Results highlighted discrepancies between the calculated values from the IGEM/SR/25 hydrogen supplement and empirical test measurements, as well as revealed the compound impact of rounding on calculated hazardous zones.
HAIM 3 will propose two methods to reduce the specified zones from AGIs based on the evidence to date:
- Refine the IGEM/SR/25 supplement based on evidence from the HAIM results.
- Use the knowledge gained during the HAIM works to adapt AGI vents and sites to reduce plume sizes and hence exclusion zones. This is independent of any changes to IGEM/SR/25 and can be applied in parallel.
Both methods independently act to reduce the specified zones surrounding vent pipes in AGIs.
Additional evidence gaps around hydrogen/Natural Gas blends up to 20% will be examined by replicating the phase 2 workshop tests for blends. During the project, additional opportunities will be sought to collaborate and share knowledge with any third-party studies of large-scale gas releases.
