Event
- Event ID
- 85
- Quality
- Description
- A jet flame occurred in a diesel distillation unit.
It was caused by the release and ignition of hydrogen from the low-pressure (60 bar) section of a the unit. It occurred during maintenance works aiming at replacing the temporary seals with definitive ones, after which the discharge valve would have been re-opened and the compressor re-started.
The unit was depressurised and the emergency status was called. - Event Initiating system
- Classification of the physical effects
- Hydrogen Release and Ignition
- Nature of the consequences
- Fire (No additional details provided)
- Macro-region
- Europe
- Country
- France
- Date
- Main component involved?
- Valve (Gasket)
- How was it involved?
- Erroneous Release & Formation Of A Flammable H2-Air Mixture
- Initiating cause
- Malfunctioning (Electrical/Electronic Component)
- Root causes
- Root CAUSE analysis
- The INITIATING cause was the fact that the discharge valve was not completely closed even though the panel control indicated that it was entirely closed.
The ROOT CAUSE could be attributed to a wrong design, which did not considered the possibility of a wrong signal on a critical component for safety.
Facility
- Application
- Petrochemical Industry
- Sub-application
- diesel distillation unit
- Hydrogen supply chain stage
- All components affected
- Gasoil distillation unit , seals
- Location type
- Unknown
- Location description
- Industrial Area
- Operational condition
- Pre-event occurrences
- Maintenance works were ongoing on the compressor on recycled gas circuit. Temporary seals had to be replaced by definitive seals.
Emergency & Consequences
- Number of injured persons
- 0
- Number of fatalities
- 0
- Official legal action
- The independent inspection required a root cause analysis and a detailed examination of the tightness of the automatic valve.
Lesson Learnt
- Corrective Measures
- The plant operator modified the system controlling the opening of the affected valve during the maintenance works.
Event Nature
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Actual pressure (MPa)
- 60
- Presumed ignition source
- Not reported
References
- Reference & weblink
Event 33030 in the French database ARIA<br />
https://www.aria.developpement-durable.gouv.fr/accident/33030/<br />
(accessed October 2020)<br />
JRC assessment
- Sources categories
- ARIA
