The incident involves a gas booster provided by a manufacturer. This device is used in the experimental platform of the project to raise the pressure in pipelines from 60 to 80 barg (from 6 to 8 MPa), allowing the gas to flow in a close loop. After 5 weeks of operation, a critical gas leakage through the vent port was detected.At the moment of the incident, the compressor was working with a mixture of hydrogen and methane (H2/CH4 blend 20/80 %v/%v). The booster was sent to the manufacturer for inspection and reparation. Severe damage in the seals of the vent port was found.

Early in the morning of (3:00 AM), the personnel on one of the companies on site reported a potential pipeline leak just south of the valve station. The potential leak was discovered due to bubbling water in the ditch. No visible hydrocarbon sheen was noted, indicating a probable non-hydrocarbon gas leak. Later in the morning, the personnel tested their area gas pipelines and determined that their company was not the source of the leak. Later on the same day, another company tested their pipelines and determined that their hydrogen pipeline was the source of the leak.

At 17:30 on 5 may 2019, the pipeline operator was notified by a third party that there was a possible leak on its hydrogen pipeline, as identified by sound. Operator personnel arrived on the site at 18:30 and confirmed that hydrogen was present in the area. The location was in an isolated area. Manual isolation valves were shut to close in the segment and it was manually blown down. At 08:52 on of the day after the operator determined that the incident met reportable criteria and called the national response centre at 09:22.

Release from a welding of a hydrogen transmission pipeline At 12:45 pm the operation control centre (OCC) recognised that a customer flow and pressure dropped significantly. At 13:28 the OCC made the decision to close the upstream remote operated valve. At 15:00 the pipeline technician arrived on site and confirmed the breach in the pipeline. Additional pipeline operations technicians were deployed to isolate both manual block valve upstream and downstream of the incident site.

A hydrogen release and subsequent fire occurred at meter station of a pipeline transporting hydrogen to a refinery. Local refinery emergency response team responded and secured the area. The pipeline was isolated, and the fire extinguished itself. During a winter storm, the area was experiencing abnormal freezing conditions and widespread power outages were occurring. As a result, third party hydrogen supply to the refinery was reduced. These upsets resulted in the need to export larger than normal flow rates on the hydrogen pipeline.

This entry refer to a series of events occurred before the date given, which corresponds to the publication of the evidences at the Int. Conference on Hydrogen Safety 2015. The nozzle/receptacle connection froze when refuelling the on-board hydrogen storage system at the lowest precooling temperature of -40 C. However, freezing did not cause apparatus damage nor hydrogen leakage. The nozzle/receptacle is thus able to fuel safely even if the nozzle/receptacle is stuck due to ice.

While filling a 9 litre gas cylinder with pressurised hydrogen in the hydrogen storage area, a blast occurred which destroyed the low pressure gauge, followed by a jet fire which damaged the surface of the cylinder.The cylinder to be filled, including pressure gauge and control system, had been provided by a third party. Its nominal pressure was 35 MPa, however the maximal pressure of this filling would have been much lower, less than 20 MPa, corresponding to the maximal pressure of the bulk storage available.

A cryogenic hydrogen laboratory had a power outage. The cryogenic hydrogen storage was no longer being cooled, therefore temperatures and pressures within the storage system started rising. There were several relief devices on the system, one with a set point of 150 psi (approximately 1 MPa) and a second at a set point of 165 psi (1.1 MPa). The system was monitored by site personnel so that when the hydrogen pressure increased to 120 psi (approximately 0.5 MPa), a manual vent was opened. However, the manual vent rate was not able to control the rising pressure.

A hydrogen safety sensor went into alarm at a hydrogen demonstration facility. The early morning temperature was near freezing and there was a trace of precipitation on exposed surfaces. Upon further inspection following the sensor alarm, a 3,500 psig (approximately 24 MPa) stationary storage vent was found to be releasing hydrogen through the PRD vent stack (PRD = Pressure Relief Device). The alarming sensor was at an adjacent building but responded to hydrogen 20 yards (18 m) downwind from the vent location. The vent release location is 10 feet (3 m) above ground level.

An explosion followed by a fire occurred at a tar precipitator of gas treatment of a coke oven. The extractors were manually activated. Ten minutes later, the operator activates the internal emergency plan. The fuel supply to the installation was interrupted. Approximately two hours later the fire was extinguished by nitrogen inerting. The operator estimated the maximum amount of material that reacted in the explosion of the tar precipitator at 170 kg in TNT equivalent.