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.
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, the ignition of the H2 at the vent of a LH2 tank was reported 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
- Component involved
- cryogenic pump
- Failure mode
- leak & ignition
- Initiating cause
- unknown
- Root CAUSE analysis
The INITIATING CAUSE was the damaging of the LH2 pump: the cam of the turbo pump broke, causing hydrogen gas to leak out.
ROOT CAUSE is unknown.- Root causes
- Date entry in HIAD
- 01/01/2020
Facility
- Application
- Non-road vehicles
- Sub-application
- Aerospace
- Hydrogen supply chain stage
- All components affected
water pump, rocket engine, liquid hydrogen tank
- Process temperature range [C]
- cryogenic temperature (below -50°C)
- Location type
- Unknown
- Location
- unknown
- Operational condition
- Pre-event occurrences
A test was ongoing
Emergency & Consequences
- Number of fatalities
- 0
- Number of injured persons
- 1
In-depth data
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Probable IGNITION SOURCE
- Explosion type
References
- Sources categories
- KHK
- Reference & weblink
High Pressure Gas Accident Cases Database of the KHK (High Pressure Gas Safety Association):
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.
