2.3a The BHOPAL Incident India, 2 Dec 84

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2.3a The BHOPAL Incident India, 2 Dec 84

• Presented to ES-317y at UWO in 1999.
• Dick Hawrelak

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UC Block Diagram
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The Catastrophe

• 54,000 lbs of extremely toxic methyl isocyanate
  (MIC) were released from an elevated stack for a
  period of nearly two hours.
• The gas cloud covered an area 2.5 km. wide by 4.5
  km. long over a densely populated area exposing
  200,000 of the 800,000 people of Bhopal.

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BHOPAL Map
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Consequences

• 2,000 fatalities were reported initially.
• 15 years later, the death toll has risen to
  4,000.
• Some 250,000 people have permanent disabilities.

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Emergency Response

• 11,500 people were hospitalized on Dec 3.
• 170,000 were treated the first few days.
• 1000 doctors, 200 nurses, 700 paramedics
  responded.
• 5 hospitals and 22 clinics were used.

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Storage Area As Designed
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Storage Area As Operated
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Sequence of Events

• Prior to the incident, there had been a reduction
  in operator staff from 12/shift to 4/shift.
• There had also been a reduction in shift
  supervisors from 3/shift to 1/shift.
• Because of these reductions, moral was low.

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Dec 2, 1020 PM

• Day shift operator reports pressure in V-610 as
  normal at 2 psig.
• The normal range of pressure is 2 to 25 psig.
• Tank contains 90,000 lbs of MIC at 75 full.
• Tank is blocked with small transfer taking place
  at 77 deg F.

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Dec 2, 1045 PM

• Shift Changes.
• Normally operators discuss problems experienced
  during their shift.
• No problems were communicated to the midnight
  shift.

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Dec 2, 1100 PM

• Control room operator notes pressure in V-610 has
  risen to 10 psig.
• There was no concern since this was still in the
  normal operating range.
• The rate of pressure rise over the 40 minute
  period was not a concern.

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Dec 3, 0015 AM

• A field operator reported a MIC in the MIC
  process area.
• This was considered to be a normal fugitive
  release and no alarms were sounded.

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Dec 3, 0016 AM

• CR operator observes V-610 pressure at 30 psig
  and rising rapidly.
• The CR operator becomes concerned and confused
  about the steps that should be taken.

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Dec 3, 0018 AM

• V-610 pressure goes off scale at 55 psig.
• CR operator runs to V-610 tank in the field.
• He hears tank rumbling, PSV screeching and
  concrete cover cracking.
• He runs back to CR turns on the vent gas
  scrubber the reirculating pump.
• The recirculating pump registers no flow.

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Dec 3, 0020 AM

• MIC production supervisor notifies Plant
  Superintendent that there is a problem in the
  storage area.

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Dec 3, 0025 AM

• Plant superintendent arrives at CR and notes much
  MIC in the atmosphere.
• He spends the next 15 minutes with the CR
  operator to learn what action has been taken.

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Dec 3, 0045 AM

• The Derivatives unit shuts-down because of the
  high MIC in the atmosphere.
• The phone lines to the CR are all busy.

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Dec 3, 100 AM

• Derivative unit sounds toxic gas alarm.
• Plt Supt MIC opr verify that MIC is coming from
  an elevated stack before the flare stack. They
  trace this back to V-610.
• They turn on firewater monitors on VGS and V-610.
• They note steam coming from the cracked concrete
  as they try to cool V-610.

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Dec 3, 100 AM to 230 AM

• Sometime during this period of time, the PSV
  reseats itself at 40 psig and the release stops.

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Reasons For The Release

• Water entered V-610 at a high enough level to
  start a polymerization reaction.
• The tank contents were initially at ambient
  temperatures and the runaway progressed unchecked
  because there was no cooling on V-610.
• The heat of reaction boiled the MIC monomer and
  54,000 lbs of MIC was released.

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Dispersion Results
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Predicted Consequences
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Lessons Learned

• V-610 refrigeration unit should never have been
  shut down to conserve energy. It was intended to
  slow a potential polymerization reaction if one
  should accidently occur.
• The VGS should never have been put on stand-by.
  It was a critical piece of equipment and should
  have been available 100 of the time, as intended.

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Lessons Learned Contd

• The caustic recirculaing pumps on the VGS should
  never be turned off. Caustic pumps often
  freeze-up when the are not in use and never
  respond on demand.
• The plant should not have been in operation
  without the flare stack, which was down for
  maintenance.

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Lessons Learned Contd

• The plant never conducted dry run or emergency
  practice drills.
• The various safety devices were not checked on a
  regular basis.
• There was no warning to the nearby community.

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Lessons Learned Contd

• There was no communication to local authorities
  regarding the hazards of the plant.
• There was no local emergency plan in place.
• The shack community was too close to the plant
  site. 6,000 to 7,000 meters was estimated to be a
  safe distance.

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Lessons Learned Contd

• When you go through cost cutting measures to save
  energy and reduce operators to save operating
  expenses, moral is bound to suffer. In this
  state, the safety integrity of the plant is often
  compromised. This situation often leads to
  sabotage or extreme actions by those losing their
  jobs.

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The Bhopal Aftermath

• Industry throughout the world responded to the
  Bhopal Aftermath by adopting the Responsible Care
  program.
• 19 resolutions were adopted based on the lessons
  learned.
• Emergency planning and green belt separation are
  required for all toxic chemicals.

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Possible Exam Questions

• What three critical equipment items were out of
  service at the time of the Bhopal incident?
• What was the global response to the Bhopal
  Incident?