| Case Name |
Fire caused due to overheat of an electric heater caused from operation error during a turnaround shutdown |
| Pictograph |
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| Date |
November 14, 1994 |
| Place |
Kawasaki, Kanagawa, Japan |
| Location |
Refinery |
| Overview |
On November 14th, 1994. At an ethyleneimine manufacturing plant under a turnaround shutdown, the heater of an empty vessel overheated and was damaged. The heat medium leaked and caught fire. Indication of the vessel that should be heated was incorrect. Moreover, the power supply cut-off system for an abnormal heater temperature rising did not operate. It seems, furthermore, that workers had been convinced that there was no abnormality because a turnaround shutdown was carried out. However, there was heat-medium oil and the heater was actually operating. |
| Incident |
During turnaround shutdown maintenance of an ethyleneimine manufacturing plant, an electric heater on an empty vessel was turned on due to miss-operation of the heaters. The electric heater was overheated and was damaged. Niter in the heater leaked, and a fire occurred.
Niter: Mixed-solution of nitrates, such as sodium nitrate. Heat medium oil. |
| Processing |
Manufacture |
| Individual Process |
Maintenance |
| Substance |
Nitrate |
| Type of Accident |
Leakage, fire |
| Sequence |
On October 14th. 1994. The ethyleneimine manufacturing plant was stopped for a turnaround shutdown.
On October 25th. The niter in the reactor and the heating vessel etc. were drawn off to a storage tank. To keep the storage tank and piping warm, a temperature control heater was switched on.
About 08:00 November 12th. The temperature control heater switch was turned off according to an order in a document about electric repair work.
16:30 on November 13th. After power supply started, "Turn on the switch of the temperature control heater" was ordered according to the document. The machine number in the document was indicated incorrectly.
20:50. The temperature control heater with the directed machine number was switched on.
21:35 or later. Temperature alarms were activated at some thermometers.
03:53 on November 14th. An alarm noticing an abnormality of the heater operated. It is presumed that the heater at an empty vessel was damaged at this time.
04:23. The fire was found.
04:33. A passerby on a public road found the fire, and made an emergency call to the public fire department.
05:28. Extinguishment of the fire was confirmed. |
| Cause |
The heater tag number in the directions document was incorrect. Therefore, the heater of an empty vessel was turned on, overheated and damaged. As a result, niter leaked and there was a fire. The heater was equipped with a power supply cut-off circuit at an abnormal temperature rising. However, the power supply of the circuit was different from the heater's power supply, and power to the circuit was cut for a turnaround shutdown. Therefore, when the power supply of the heater was switched on incorrectly, the preventive circuit was not functioning. |
| Countermeasures |
Conducting a work check with thoroughness. Operators should understand the whole system. Restudy of a safety instrumentation system.
Improvement of education, especially of the reason for work. |
| Knowledge Comment |
Usually, during a turnaround shutdown, heating operations etc. are not performed. A strict check is required when doing special operations during turnaround shutdown maintenance.
The functions of a safety instrumentation system must be independent, and should be operating during an unusual operation period. |
| Background |
1. Directions for work were incorrect. As the tag numbers of the heaters were similar, the person giving directions did not notice the error.
2. The tag number of the heater and the heater name were described in the directions document and also on the switch. However, the worker checked only the tag number of the heater, without comparing it with the heater name.
3. The worker seems not to have understood the reason for the operation, and the state of equipment. Therefore, it is thought that the worker accepted only the tag number without any question.
4. Why did not the cut-off circuit for abnormal temperature rising start before using the heater? It is presumed that there was disregard of basic operation.
5. Suitable measures were not taken although the alarm sounded. Occurrence of an abnormal situation was not thought because of a turnaround shutdown. Therefore, temperature monitoring was not carried out. There was no recognition that some units were operating even during a turnaround shut-down. |
| Incidental Discussion |
It is seldom expected that an error in documented directions will be corrected during work. When preparing directions, every caution is required. |
| Reason for Adding to DB |
Example of fire caused due to work during a turnaround shutdown |
| Scenario |
| Primary Scenario
|
Poor Value Perception, Poor Safety Awareness, Inadequate Risk Recognition, Organizational Problems, Poor Management, No Function of Checking, Carelessness, Insufficient Precaution, Obscure Indication, Usage, Operation/Use, Electric Heater On, Non-Regular Movement, Movement During Transition, Operate without reconfirmation, Failure, Large-Scale Damage, Rapture, Secondary Damage, External Damage, Leakage/Fire
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| Sources |
High Pressure Gas Safety Inst. of Japan, High-pressure gas protection overview, pp.260-261 (1996).
Kawasaki City Fire fighting station, Prevention division, Peace section. N Co. Ltd. K factory. Outline of fire at ethyleneimine factory, Material of the Kawasaki City Complex safety countermeasures committee, (1995).
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| Physical Damage |
One heater. Cables etc. |
| Field |
Chemicals and Plants
|
| Author |
ITAGAKI, Haruhiko (Japan National Institute of Occupational Safety and Health)
TAMURA, Masamitsu (Center for Risk Management and Safety Sciences, Yokohama National University)
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