3171 Case Studies

Bhopal - hazards

reactivity and toxicity

Bhopal - initiating event

water intruded into an intermediate storage vessel

Bhopal - loss event

40 MT of MIC gas released to the atm

Bhopal - consequences

3,000 fatalities, injuries ranging up to hundreds of thousands

Bhopal - lessons

1. Process safety culture - cost pressure in preparation for shutdown, cut staffing and training

2. HIRA - inherently safer design - large intermediate inventory not needed

3. MOC - disabled safety systems (pressure gauges, hi temp alarms, scrubbers)

Dupont case study- hazards

toxicity

Dupont case study- loss events

two pounds of phosgene released from hose rupture

Dupont case study- consequences

one fatality, 3 exposures, national media attention

Dupont case study- initiating event

hose blocked in, trapped phosgene

Dupont case study- lessons

1. Process safety culture - inherently safer design reccomendations not taken (containment building, tubing material)

2. Incident Investigation - recent hose failure not investigated

3. Missed hose PM, MOC to inspection

T2 labs case study - hazards

Reactivity (runaway), flammability, overpressure

T2 labs case study - initiating event

loss of cooling

T2 labs case study - consequences

explosion equiv to 1400lb of TNT

T2 labs case study - lessons

1. Process safety competency - lack of experience, did not understand hazards

2. HIRA - hazop not done on reactor scaling

3. MOC - increased batch size with no safety review

4. Exotherms occurred without review

BP America (Texas City) Refinery Explosion - hazards

flammability

BP America (Texas City) Refinery Explosion - initiating event

overfill raffinate splinter on startup

BP America (Texas City) Refinery Explosion - loss event

50,000 lbm of hydrocarbon released

BP America (Texas City) Refinery Explosion - consequences

15 fatalities, 180 injuries, regulatory fines, reforms in various industrial process safety practices

BP America (Texas City) Refinery Explosion - lessons

PROCESS SAFETY CULTURE,

1. inadequate operation readiness

2. lack of supervisory oversight during start up

3. SOP & training inadequate

4. complacency (consequences of operations - shift change, shift log, fatigue)

Chevron Richmond Refinery case study - hazards

flammability, toxicity, corrosivity

Chevron Richmond Refinery case study - initiating event

sulfidation corrosion caused pipe failure

Chevron Richmond Refinery case study - loss event

15000 lbm light fuel oil vapor from crack in distillation side of cut line

Chevron Richmond Refinery case study - consequences

15000 people in community affected, 20 hospitalized

Chevron Richmond Refinery case study - lessons

1. Asset integrity - multiple opportunities to replace w materials resistant to sulfidation corrosion

2. Incident investigation - failure had occurred in similar service at another chevron refinery

3. PSC - stop work authority, repair extensions

MGPI Processing Case study - hazards

reactivity, toxicity

MGPI Processing Case study - initiating event

human error, connected unloading hose to wrong vessel

MGPI Processing Case study - loss event

chlorine mass not specified, could have used source model

MGPI Processing Case study - consequences

medical attention for 120-140 people in community

MGPI Processing Case study - lessons

1. Human factors - poor equipment labeling and connection design

2. inadequate unloading procedures - driver left unsupervised, no verification to confirm lineup

3. Lock or automated safeguard - no shutoff or isolation system