Texas oil refinery explosion

Arpit MathurM.Tech DM Ist year

Accident data

• Industry name :- British Petroleum oil refinery

• When :- march 23rd , 2005• Where :- Texas, USA • Time :- between 12:30 pm to 1 pm• Deaths :- 15• Injuries:- 170• Reason:- A hydrocarbon vapour cloud

exploded at the ISOM isomerization process unit

ABOUT THE INDUSTRY

• The Texas City Refinery was the second-largest oil refinery in the state, and the third-largest in the United States with an input capacity of 437,000 barrels (69,500 m3) per day as of January 1, 2000. BP acquired the Texas City refinery as part of its merger with Amoco in 1999.

ISOM UNIT

Closed

ClosedSight-glass dirty &

unreadable – Leveltransmitter not

calibrated Indicated 10 ft and falling

Inoperative

Inoperative

Redundant Alarm

Inoperative

The Causes

• Actions and errors by operations personnel were the immediate causes of the accident.

• Latent conditions and safety system deficiencies influenced personnel actions and contributed to the accident - and collectively influenced the decisions and actions of operations personnel.

• Safety system deficiencies created a workplace ripe for human error

Personnel Actions & Errors

• Required pre-start actions not completed– Pre-Startup Safety Review not performed– Key malfunctioning instrumentation not repaired– Malfunctioning pressure control valve not repaired --

supervisor signed off on startup procedure that control valves had tested satisfactorily

– Functionality checks of alarms and instruments not completed

– Review of startup procedures by operators and supervisors not completed

• Night Lead Operator did not use startup procedure or record completed steps when startup was partially completed on night shift

Personnel Actions & Errors (Cont’d)

• Night Lead Operator left an hour before end of shift• ISOM-experienced Day Supervisor A arrived over an hour

late - did not conduct shift turnover with night shift personnel

• Day Supervisor B was told that startup could not proceed because storage tanks were full - not communicated to ISOM operations personnel

• Day Board Operator closed automatic tower level control valve – although procedure required valve to be placed in “automatic” and set at 50 percent

• Day Supervisor left the plant due to family emergency as unit was being heated

Latent Organizational Weaknesses

• Work environment encouraged procedural noncompliance

• Ineffective communications for shift change and hazardous operations (such as unit startup)

• Malfunctioning instrumentation and alarms• Poorly designed computerized control system • Ineffective supervisory oversight • Insufficient staffing• Lack of a human fatigue-prevention policy• Inadequate operator training for abnormal and

startup conditions• Failure to establish effective safe operating limits

Latent Organizational Weaknesses

• Ineffective incident investigation management system

• Ineffective lessons learned program • No coordinated line management self-

assessment process• No flare on blow down drum • No automatic safety shutdown system• Key operational indicators and alarms

inoperative• Ineffective response to serious safety

problems and events• Focus on injury and illness statistics, not

process safety

• Poor implementation of Process Hazards Analyses (PHA) and Management of Change (MOC) processes (equivalent to USQ)

• Ineffective follow-up on audit reports

• Problem reporting not encouraged

• Inadequate implementation of OSHA Process Safety Management regulations

• Inadequate OSHA inspections and enforcement

• Gaps in applicable industry standards

Latent Organizational Weaknesses

Aftermath• In 1991, the Amoco refining planning department proposed

eliminating blowdown systems that vented to the atmosphere, but funding for this plan was not included in the budget.

• In 1992, OSHA issued a citation to Amoco for unsafe design of similar pressure-relief systems at the plant. However, Amoco successfully persuaded OSHA to drop this citation by relying on the less-stringent requirements in API Recommended Practice 521.

• In 1993, the Amoco Regulatory Cluster project proposed eliminating atmospheric blowdown systems, but again, funding was not approved.

Aftermath• In 1995, a refinery belonging to Pennzoil suffered a disaster

when two storage tanks exploded, engulfing a trailer and killing five workers. The conclusion was that trailers should not be located near hazardous materials. However, BP ignored the warnings, and they believed that because the trailer where most of the deaths happened was empty most of the year, the risk was low.

• Despite Amoco's process safety standard No. 6, which prohibited new atmospheric blowdown systems and called for the phasing out of existing ones, in 1997, Amoco replaced the 1950s-era blowdown drum/vent stack that served the raffinate splitter tower with an identical system, instead of upgrading to recommended alternatives that were safer.

Aftermath

• In 2002, engineers at the plant proposed replacing the blow down drum/vent system as part of an environmental improvement initiative, but this line-item was cut from the budget, due to cost pressures.

• Also in 2002, an opportunity to tie the ISOM relief system into the new NDU flare system was not taken, due to a US$150,000 incremental cost.

Aftermath• During 2002, BP's Clean Streams project proposed

converting the blow down drum to a flare knock-out tank, and routing discharges to a flare. When it was found that a needed relief study of the ISOM system had not been completed due to budget constraints, the Clean Streams project proposed adding a wet/dry system to the ISOM instead.

• Between 1994 and 2004, at least eight similar cases occurred in which flammable vapors were emitted by a blow down drum/vent stack. Effective corrective action was not taken at the BP plant

Result

• As a result of the accident, BP said that it would eliminate all blow down drums/vent stack systems in flammable service. The CSB, meanwhile, recommended to the American Petroleum Institute that guidelines on the location of trailers be made.

• OSHA ultimately found over 300 safety violations and fined BP US$21 million — the largest fine in OSHA history at the time

Legal actions

• BP was charged with criminal violations of federal environmental laws, and has been named in lawsuits from the victims' families.

• The Occupational Safety and Health Administration gave BP a record fine for hundreds of safety violations.

• In 2009 imposed an even larger fine after

claiming that BP had failed to implement safety improvements following the disaster

Subsequent incidents• On July 28, 2005, a hydrogen gas heat exchanger pipe on the

reside hydrotreater unit ruptured.

• On August 10, 2005, there was an incident in a gas-oil hydrotreater that resulted in a community order to shelter.

• On January 14, 2008, William Joseph Gracia, 56, a veteran BP operations supervisor, died following head injuries sustained as workers prepared to place in service a water filtration vessel at the refinery's ultracracker unit.

• On September 21, 2010, an incident in the Pipestill 3B unit left two workers with serious steam burns.

Thank you