Event
- Event ID
- 256
- Quality
- Description
- A hydrogen leak occurred on the a coolant pipe of an electrical generator located in the turbine building, at 200 m from the reactor. Because of the welding works ongoing at that moment on the pipe, the hydrogen ignited and an explosion and a fire followed the leak, with one fatality and a severe injury. The fire brigade of the plant were able to extinguish the fire.
There has not been any radioactive release, because the accident occurred in the non-nuclear area of the plant.
According to the source (ARIA) the investigation attributed to a human error the cause of the incident. - Event Initiating system
- Classification of the physical effects
- Hydrogen Release and Ignition
- Nature of the consequences
- Macro-region
- Europe
- Country
- Ukraine
- Date
- How was it involved?
- Leak & Formation Of A Flammable H2-Air Mixture
- Initiating cause
- Unknown
- Root causes
- Root CAUSE analysis
- Soldering work was ongoing on the pipe when the incident occurred. Authorities pointed out a human error. However, with the scarce information available, the cause could be equally well be attributed to wrong (maintenance, purge) procedures.
Facility
- Application
- Power Plant
- Sub-application
- Nuclear power plant
- Hydrogen supply chain stage
- All components affected
- cooling system, turbine-compressor unit, turbine bulding
- Location type
- Confined
- Location description
- Industrial Area
- Operational condition
- Pre-event occurrences
- The nuclear reactor was stopped and under maintenance. Soldering work was ongoing on the affected pipe.
Emergency & Consequences
- Number of injured persons
- 2
- Number of fatalities
- 1
- Post-event summary
- There has not been any radioactive release, because the accident occurred in the non-nuclear area of the plant.
- Emergency action
- The emergency was quickly ended by the intervention of the drivers, who performed a manual pressure release operation.
Lesson Learnt
- Lesson Learnt
The ARIA report does not mention any lesson learnt, only the probable classification of the accident to a human error. The event description does not provide enough details to draw specific conclusion. Nevertheless, soldering/welding a hydrogen-containing component requires always the preliminary evacuation of the hydrogen, what does not seems that has happened in this case.
In alternative to a human error, this event could also hint at lack of adequate procedures, their or inadequate communication.
Event Nature
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Presumed ignition source
- Welding
- Deflagration
- Y
- High pressure explosion
- N
- High voltage explosion
- N
- Flame type
- Other
References
- Reference & weblink
Event description in the French database ARIA<br />
https://www.aria.developpement-durable.gouv.fr/accident/4501/<br />
(accessed December 2020)<br />
JRC assessment
- Sources categories
- ARIA