Event
- Event ID
- 629
- Quality
- Description
- An explosion occurred at a aerospace testing centre, while testing a liquid hydrogen turbo-pump, part of a rocket engine. On the day of the incident, seven seconds after the rotation speed of the pump had reached its steady state (45,000 rpm), excessive vibration was detected. The pump was stopped but a loud bang was heard. The operator started to inject nitrogen gas. One and a half minutes after the bang, flames were seen in front of the testing building, coming from burning cables.
An investigation revealed that the cam of the turbo pump damaged, causing hydrogen gas to leak out.
Hydrogen gas discharged from the vent stack on a liquid hydrogen tank also caught fire.
[Note of HIAD validator: this report was orignally provided by the database RISCAD, now uanvailable. It is now in the KHK database (see references). Details are unclear, probablydue to the machine translation from Japanes. For example, it is unclear what a 'cam' is in this case, and the escalation to the LH2 tank was reproted only by RISCAD, not by KHK]. - Event Initiating system
- Classification of the physical effects
- Hydrogen Release and Ignition
- Nature of the consequences
- Macro-region
- Asia
- Country
- Japan
- Date
- Root causes
- Root CAUSE analysis
- The INITIATING CAUSE was the damaging of the LH2 pump.
ROOT CAUSE is unknown.
Facility
- Application
- Non-Road Vehicles
- Sub-application
- Aerospace
- Hydrogen supply chain stage
- Hydrogen Storage (No additional details provided)
- All components affected
- water pump, rocket engine, liquid hydrogen tank
- Location type
- Unknown
- Operational condition
- Pre-event occurrences
- A test was ongoing
Emergency & Consequences
- Number of injured persons
- 1
- Number of fatalities
- 0
Event Nature
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Presumed ignition source
- Electricity
References
- Reference & weblink
High Pressure Gas Accident Cases Database of the KHK (High Pressure Gas Safety Association): <br />
https://www.khk.or.jp/public_information/incident_investigation/hpg_inc… />
(accessed May 2025)The first entry in HIAD was coming from RISCAD, which is now closed.<br />
JRC assessment
- Sources categories
- KHK
