On 2nd and 3rd December, 1984, Bhopal city in India became popular in all parts of the world. Unfortunately, the popularity came from the most negative event the city could imagine. The night separating the two dates witnessed a cruel event where the Union Carbide Pesticide Plant collapsed. The event released great volumes of poisonous gases to the atmosphere. The disaster caused thousand s of several people dead and many injured (Eckerman 2001). Bhopal city would have coped with the impacts of this disaster was it not for the following facts:
- More than 3000 people died instantly. However, the deaths did not stop at that. In fact, statistics show that more than 20,000 people died about 120,000 people suffer up to date as a result of this disaster.
- The accident was waiting to happen, and was given a chance to happen. In India, human life was not given high priority as other nations. The firm had been neglected as the operators cared less about safety of the society and workers.
- The managers at the plant lied to the society that the gases emitted were harmless. They claimed that, Methyl Isocyanate only acted as tear gas and could not harm human beings exposed. In fact, the Indian Government and the Union Carbide Corporation claimed this until 1994.
- The event was preceded by warning events since 1976. However, the neither Corporation took a step to curb the faultiness noted nor did they take action to lessen the consequences of such an event could it happen. Additionally, no one was jailed or questioned for such irresponsibility.
- Scientists within the Corporation had forecasted such an incident some months before the event. However, the reports were ignored, and not taken to the senior staff.
Objectives of the study
This study aims at producing a Fault Tree to help identify lessons learnt from the Bhopal Disaster. It shows that this was a disaster waiting to happen. This will be achieved through
- Assessing the technical causes of the disaster response failure from operations and design perspective.
- Identifying the main causes of failure at that time and to date.
- Using Reliability Block Diagram and Fault Tree analysis to assess the probability of reoccurrence of such an occurrence.
- Using Minimal Cut Set method, to recreate another Fault Tree analysis.
- Recommending what should be done in contingency and emergency planning.
The Union Carbide India Ltd (UCIL was established in 1969 at Bhopal, India. The corporation offered competitive advantages since it had low labor costs. The corporation grew rapidly with its low operating costs. The pesticide manufacturing company imported the main component in production, Methyl Isocyanate (MIC) from its parent company till 1976 (Eckerman 2004). The Bhopal Gas Leak, which occurred on 2nd and 3rd December 1984 in India, is up to date the largest chemical industrial accident to occur in this planet. The disaster claimed more than 2,000 lives instantly. More than100, 000 people were injured and more than 520,000 exposed to dangerous gases. The impacts of this disaster are still felt today since many people acquired permanent injuries (Weir 1987). Properties worth millions of dollars were destroyed. The environment was degraded and the air polluted. This catastrophe occurred as s result of human negligence. It has remained a symbol of human negligence from multinational corporations. This served as an international alarm clock on the impacts of negligence and ignorance. However, industrial disasters continue happening in different parts of the world. India and other parts have from then witnessed other chemical industrial accidents, but none can surpass the Bhopal Gas Leak of 1984.
The current accidents are much far as compared to the Bhopal Gas Leak (Eckerman 2001). However, chemical hazards are numerous top an extent that they are now considered as public health problem. They are posing a threat to life and health as well as property and environment. It is unfortunate that even after 28 years down the line, the companies responsible for the accident dispute their roll to the accident. They deny the health impacts of the accident. Additionally, the companies have been unenthusiastic to compensate the victims and their families economically. It is still not clear what caused the Bhopal Gas Leak. There are various answers on who was responsible for the hazardous event. According to the Union Carbide, the event occurred as a result of a disgruntled employee who interfered with the system (Fortun 2001).
In injury and risk analysis, the notion “process of the accident”, is used. This includes the pre-disaster, disaster event and post-disaster analysis. These models are usually used for occurrences children’s burns and traffic accidents. The Fault Tree Analysis (FTA) and Reliability Block Diagram (RBD) are applicable in the Bhopal Gas Leak. Two models assess injury analysis and the causes of failure in emergency response of this disaster (Cassels 1993).
The installation of the MIC plant at Bhopal was designed and constructed with cut cost programs. These include
- Carbon steel piping replaced the stainless steel piping. Carbon steel is more corrosive than the carbon steel.
- The quality and number of safety devices was deducted to increase savings.
- Manual safety devices were installed instead of the automatic ones.
- Early warning systems were not installed
- Only one vent gas scrubber was installed. This caused redundancy.
- A single flare tower was fixed.
- There was no unit storage reservoir between the large storage container and the MIC manufacture to check purity of the products.
- The six safety features of this plant were inefficient for a period of time. Additionally, none of these features was operating on the night of the disaster as a result of understaffing.
- There was no emergency planning connecting the locals to the plant.
- Experts from US had audited the plant and recommended several maintained issues. There is no evidence that these recommendations were considered or implemented. This indicates negligence.
- Between 1980 and 18984, training and education standards of workers were reduced. The workforce was reduced by 50% without reasonable investment in modern technology to authorize this reduction.
Direct Causes of the Accident
On the night of the event, dangerous gases were emitted for 2 hours 15 minutes (Shrivastava 1987). The main factors contributing to this disaster include, but not limited to the following:
- 1. The storage tank was filled beyond capacity. The functional gauges should have signaled this and halted the process until rectified.
- 2. The reserve container was full of Methyl Isocyanate. This should have been empty to allow flow in case of an emergency.
- 3. The blow down valve of tank number 610 was faulty but was permanently open. Instead, this valve should have been repaired, or the tank removed until required repair was made.
- 4. Alarm sirens, which were to warn the community in case of emergency, were switched off after five minutes. This should have continued for several hours to raise alarm in the community.
- 5. The management failed to notify external emergency agencies of the incident immediately. Instead, the superintendent denied that such an event had occurred. The management should have reported to other emergency agencies to seek assistance and mitigate such occurrences.
- 6. The civic authorities lacked knowledge and experience of dealing with such incidences. They had no uniforms and materials to respond to such incidences. Emergency response personnel should be well equipped to deal with all emergency situations.
- 7. Temperature and pressure measuring gauges were so notorious to extent that the workers ignored their warnings. This should have been corrected. The safety culture should be as serious as possible in an organization.
- 8. The refrigeration section, which maintained the MIC’s low temperature and prevented overheating in case of contamination, was temporally closed. This unit should have been repaired and resolved instead of closing it.
Calculation and Theory
The Fault Tree Analysis (FTA) and the Reliability Block Diagram (RBD) map the main causes of the disaster as well as calculate the probability of reoccurrence. Reliability Block Diagram is derived from the Fault Tree Analysis. The RBD indicates the interdependence of causes which led to the failure at the climax of the Fault Tree. The RBD and FTA model help highlight weak or vulnerable areas that require attention. This includes area s like preventative maintenance, redundancy and built-in-testing. Secondly, the model shows how a system fails. Therefore, it can be used for fault finding or diagnostics. Lastly, the model can be used to determine the systems reliability based on the values in each box. Normally, RBD and FTA model is used in minor occurrences, which require machine or equipment. However, from this case, the model is used in analyzing a catastrophe. The Bhopal is a complex case which influenced social, environmental and human factors. Additionally, the case is complicated and can bring confusion and debate in analysis (Berger & Mohan 1996). The catastrophe poses a question, which is fundamental in disaster risk assessment: should the total availability of a Bhopal offer protection against such an occurrence whether of a high figure or low figure?
Answering this question requires one to go back to the definition of the terms involved. Availability is the average between frequency and severity failure, that is, a measure of reliability and maintainability. A disaster is naturally severe and rare. One expects high figures as far as availability of securing its occurrence is concerned. This is because a disaster has a low frequency. However, this is not the case when existing operation and design are not fit for protecting occurrence of a disaster. In such a situation, the disaster waits to happen, and the total availability of the system is low.
Discussion and Conclusion
The corporation had concentrated on profit and allowed safety maintenance and standards to deteriorate. The reports for a potential hazard had been reported two years prior to the disaster the management ignored them. UCIL did not care for the safety standards of the Bhopal plant. The Indian government failed to implement environmental and safety standards, and this is why all this happened in a country with a government. The Indian government concentrated on attracting foreign investors at the expense of the safety and health of citizens. Environmental and safety laws should be implemented in all nations to avoid such an incident. Life should be valued than profit. In future manufacturing plants, safety and standard materials and policies should be put in place and valued. Concentrating on profits only can cause untold loss in the long run as it happened to the Bhopal disaster (Chouhan 2005).