Explosion on a Turbine-Generator Unit of a Power Plant
There was a massive explosion at one of the generator-turbine units of a coal-based power station. Undetected hydrogen leak from the generator was identified as a major trigger.According to the news, some workers, unaware of the leak, were trying to fix some dirt blocks and loose nuts and bearings in the generator. Just below was an oil tank. Fire sparked spread in minutes up to 16 metres, setting off the blast with a heavy noise.It took hours to control the fire. Four persons were injured.
Event Date
November 13, 2019
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Cause Comments
The initial cause of the leak is unknown. The released hydrogen ignited possibly because of the activities of workers using non spark-free tools. Escalation may have occurred due to the proximity of an oil tank. There are also doubts on the proper or effective actions of the fire extinguisher. The root case could be attributed in general to lack of safety measures, procedures and/or practices
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
turbine, Colling system
Storage/Process Medium
Location Type
Location description
Industrial Area
Operational Condition
Pre-event Summary
The turbine-generator affected was a 500 megawatt and was commissioned in 2011. Hydrogen was used as coolant. According to the news, some workers, unaware of the leak, were trying to fix some dirt blocks and loose nuts and bearings in the generator.
Property Loss (onsite)
Total loss of vehicle.
Lessons Learned
Lessons Learned
The undetected releases of hydrogen used as cooling agent of a turbine or generator are often cause or contributor to sever damage of the unit (se for example HIAD event 1000). In this particular case it is unclear if the hydrogen leak had been detected. Anyhow, the unit was not shut down before escalation took place.
Event Nature
Emergency Action
It took hours to control the fire.
Emergency Evaluation
Despite the fact that a shut-down of the plant is foreseen in case of hydrogen leakage, the plnat was not shut-down. Probably also the fire estinguishers did not function effectively.
Release Type
Release Substance
Hydrogen Release Concentration (%)
99.40
Ignition Source
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References