Explosion in a Metallurgy Plant
Explosion within a blast furnace occurred at the plant manufacturing iron. The event occurred at one of the blast furnace of the plant, which exploded. The explosion was so powerful that the entire furnace, which with its contents weighed approximately 5000 tones, raised some 0.75 m from its supporting structures, leading to the explosive release of hot material: the released substances, 200 tones in total, consisted in solids, semi-solids, (molten metal) and gases. The event caused three fatalities, twelve severely injured workers and many more with minor injuries. The explosion occurred after two days in which it had been attempted to recover the furnace from a chilled-hearth situation caused by cooling water ingress. The water leak into the furnace also caused an increase in temperature of the molten metal, and the production of hydrogen and oxygen via thermolysis (dissociation of water by heat). The hydrogen detectors gave an increased concentration levels: instead of the usual signal below 2%, during the previous two days the hydrogen detectors reading could exceed 7%. The released gases were mainly carbon monoxide and hydrogen.
Event Date
November 8, 2001
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Cause Comments
The immediate cause of the explosion was water and hot molten materials mixing within the lower part of the furnace vessel.At the origin of this situation was the failure of safety-critical water cooling systems, which cased water entering the furnace. According to the HSE report (see references), the intermediate causes were failures in health and safety management., which were not only confined to the blast furnace plant, but extended elsewhere within the company (in particular to the department supplying cooling water for the furnace). There was insufficient redundancy and security of cooling water supplies, and overall cooling system reliability showed a downward and deteriorating trend over several months.The root case was the lack of a suitable and sufficient risk assessments for blast furnace operations, having as a consequence the failure to implement robust technical and procedural controls.
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
blast furnace
Storage/Process Medium
Location Type
Location description
Industrial Area
Operational Condition
Pre-event Summary
Manufacture of iron in blast furnace and associated generation of blast furnace gas. A detailed description of the facility can be found in the HSE report (see references). In the two days before the explosion, workers had unsuccessfully attempted to recover the furnace from a chilled-hearth situation caused by cooling water leakage. At the time of the explosion, attempts were continuing to rectify the abnormal operating conditions that this had created and to recover the furnace.
Lessons Learned
Lessons Learned
As explained in more details in the HSE report, the main lessons learned and the corrective actions were:1.The Safety Department has to be integrated into operational and engineering management.2.Since the accident, the blast furnaces have been brought under the COMAH regime (Control of Major Accident Hazards Regulations, in place since 1999). In this way, predictive tools for the assessment and management of risk received greater use within the steel industry. Examples of predictive tools are: Hazard and Operability Studies (HAZOPS), Failure Modes and Effects Analysis (FMEA), Fault Tree Analysis (FTA), Process Hazard Review (PHR) and Layers of Protection Analysis (LoPA).3.AS critical element of the process and its safety, the furnace water supply systems should have an adequate level of reliability built into the system. This reliability should be guaranteed by an adequate level of redundancy and suitable maintenance, and monitored to identify any threats to its integrity. 4.Early detection of water leak is an essential preventive measure. The appropriate instrumentation, specifically designed for leak identification, should be installed to give earlier and more precise detection of leaking elements. 5.There was a lack of knowledge of the changing status of the furnace. Despite the presence of quantitative data on liquid iron levels, hydrogen levels and the evolution of other parameters, a competent senior manager was missing. Nobody was able to overview the developments and interpreting the critical parameters. Further recommendations were issued for the improvement of the management of emergency (a clear line of responsibility was missing) the design of blast furnaces, and the preparedness of the employees (understanding of the industrial processes, safety training).
Event Nature
Emergency Action
The on-site and off-site emergency plans were initiated, and Fire, Police and Ambulance services soon had a strong presence on site. The furnace areas was cordoned off by the Police to limit access. Control centres were set up at the scene and at Port Talbot Police Station. Local government facilities were used to keep relatives and members of the public informed.
Emergency Evaluation
Overall emergency response was acceptable, and an early review of the emergency response has generated improvement plans.
Release Type
Release Substance
Ignition Source
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
Health and Safety Executive, Investigation report of the accident, with lesson learned and recommendations.
Event description in the European database eMARS
https://emars.jrc.ec.europa.eu/en/eMARS/accident/view/cdcd4047-ff7d-6a4…
(accessed October 2020)