Decision-Making in an Emergency
The United States Chemical Safety Board (CSB) has released its report ‘Fatal Equipment Rupture Explosion and Fire at the KMCO Chemical Facility’. The explosion occurred in Crosby, Texas on April 2nd 2019, and led to the death of one employee, serious injuries to two more, and lesser injuries to 28 other people.
As always, there are many important lessons to be learned from these reports. The CSB headline identifies three safety issues:
Emergency Response,
Remote Isolation, and
Hazard Evaluation.
In addition to the above findings, the following items provide valuable process safety management insights.
Piping Pressure Protection
Hazards analysis teams are sometimes confronted with the question, ‘When is a pipe a vessel?’ The answer to this question is important because vessels are required to have over-pressure protection, whereas piping usually is not. The CSB report states,
. . . none of KMCO’s hazard evaluations identified the potential for liquid thermal expansion or other possible scenarios to develop high-pressure conditions within the piping system that included the y-strainer. As a result, unlike other portions of KMCO’s isobutylene piping, this piping section was not equipped with a pressure-relief device or otherwise protected from potential high-pressure conditions.
In other words, the hazards analysis team did not have a systematic means of determining when piping required pressure protection, and when it did not. The piping failure in this case would likely have been prevented had a pressure safety relief valve been installed.
Decision to Act Quickly
Some years ago, your author was witness to an incident that occurred at a large oil refinery. A two-pump system was used to transfer a liquid hydrocarbon from one section to another. One pump was operating, the other was on standby. The liquid being pumped was highly flammable and there was a fired heater close by.
A seal on the operating pump failed, resulting in the liquid spraying out. A unit supervisor, who worked in another area of the refinery, was walking by. He was faced with an immediate choice ― should he walk quickly to the pump, shut it down, block it in, and start the spare pump? Or should be retreat to the control room and let the technicians take charge?
He chose the first course of action and operations continued with only a minor interruption. Nevertheless, with hindsight, it could be argued that he made the wrong decision. Had the liquid ignited while he was present, he could have been killed or seriously injured.
The actions taken by the operators at the KMCO facility reminded me of that incident. The CSB report states,
. . . the three KMCO workers who were fatally or seriously injured (Board Operator 2, Board Operator 1, and the Shift Supervisor) were all in a safe location. The two board operators were working inside the blast-resistant Reaction Control Room, and the supervisor was attending a safety meeting in a conference room within the plant’s administration building. When the flammable isobutylene vapor cloud exploded 11 minutes later, all of these workers were in harm’s way; and were fatally or seriously injured while performing actions either within or near the flammable isobutylene vapor cloud.
Had the Board Operators and Supervisor remained in a safe location they would presumably have not been injured. They took heroic action to prevent catastrophe, but, as we have seen, the plant was finally demolished anyway.
The Fire Chief is quoted as saying,
If [the operators] can go out there and block it in, theoretically, real quick and, like, neutralize it or keep it contained, that’s going to be their primary thought pattern. A Good Samaritan, they want to do the right thing right away.
Probably the key words in this part of the incident analysis is ‘Good Samaritan’. People want to do the right thing in order to protect the unit, even if it puts them into a dangerous situation.
Eventual Bankruptcy
The company involved, KMCO, filed for bankruptcy following this event. The facility was purchased by another company, but they demolished the unit in which the incident occurred.
Economic loss can never be compared to the loss of life and injuries to personnel. Nevertheless, this incident does demonstrate that investment in process safety management can be justified on economic grounds.
