Monday, December 15, 2008

Explosion in Tyler: More Questions than Answers

Over the weekend I heard a short news item about an explosion and fire at an oil refinery in Tyler, Texas. Here is the fruit of less than an hour's web research on what happened:

Tyler is a town of about 100,000 in East Texas. Among its industrial facilities is a smallish oil refinery (it's the 94th largest in the U. S.) owned by an Israeli company called Delek USA. On Thursday afternoon, Nov. 20 of this year, a part of its saturated gas unit exploded and caught fire. Four employees of the company were hospitalized, and two of them died later of their injuries. About 2,000 gallons of gasoline spilled into a nearby creek during the accident, but didn't catch fire. Five employees have filed suit in a Houston court over injuries suffered in the blast. The U. S. Chemical Safety and Hazard Investigation Board has not yet posted a notice of investigation for this accident.
The plant has been shut down since the explosion and no one is saying when it might start up again.

As oil refinery accidents go, this one is not in the major leagues. The 2005 BP refinery accident in Texas City, Texas that killed 15 people is probably the most recent leader in that regard, if we judge by the number of fatalities. But the death or injury of even one person in any engineered facility is the result of something that shouldn't have happened.

I wish I could present you with a complete story of exactly what went wrong in Tyler that day and how it could have been prevented. But alas, it is not my job to gather such information from primary sources. Investigators from insurance companies or perhaps the Federal government will undertake that arduous and exacting task, equipped with tools and knowledge that such specialists have. In a few months, perhaps, the truth will emerge about what caused the accident. If history is any guide, human error will have turned out to play some role.

There are a lot of good reasons why refineries are such dangerous places. Just handling millions of gallons of highly flammable liquids and gases involves considerable risks on its own, even if you're not doing anything to make matters worse. But that is how refineries operate: you take combustible crude, run it through pipes surrounded by intense flames, squeeze it under tremendous pressure that will use any slight excuse to shoot flammable stuff out into the air where it will spontaneously burn because it's so hot, and then subject it to all sorts of chemical indignities with catalysts, further heating, pressure, toxic acids, and so on.

It would be bad enough if it was simple, but refineries are some of the most complex large systems on Earth: thousands of pipes, pumps, valves, tanks, sensors, actuators, and other stuff, all having to be operated just so or else you're in big trouble fast. The fact that we don't have refinery accidents every day is a testimony to the incredibly disciplined management and training that has to go into good refinery operations. Refinery employees have hard, dangerous jobs, and most of them do their jobs well. But not always, especially if they or their managers get careless or squeezed by cost issues into deferring necessary maintenance or safety practices.

Equipment failure, while not unheard of, is something that can almost always be prevented. The physics and chemistry of how steel fails and how chemicals behave are well enough understood that chemical engineers can predict what's going to happen in almost any given case. The problem is making sure that knowledge is applied at the right time in the right way.

The fact that the Tyler plant is owned by an offshore firm may not have any bearing on the accident. But responsibility is a funny thing: like radio waves, it tends to weaken over long distances. This is not to say that all companies based in the U. S. act more responsibly than any foreign firm—that is silly. But the point is that if nationalism means anything at all, and there is abundant evidence to show that it does, people are going to be more conscientious about protecting the lives and wellbeing of fellow citizens before they will look out for the interests of foreign nationals. It is a natural human tendency, but one that must be fought against when the situation of foreign ownership of plants arises. Years ago, when it was more common to find American firms owning offshore factories, the temptation was to neglect safety for non-American native populations, and tragedies such as the Union Carbide Bhopal disaster in India were the result. Now that ownership of manufacturing facilities seems to have become anathema to U. S. businesses, the shoe is on the other foot. Such refineries and plants that we have here are increasingly owned by foreign firms, whose owners may or may not be as careful to ensure safe working environments as U. S. owners might be.

We will simply have to wait to find out more about what happened in Tyler last November 20. But let's hope that any lessons we can find out will be learned well by everyone who has anything to do with oil refinery safety or engineering.

Sources: I have used information from the following sources: http://www.haaretz.com/hasen/spages/1044426.html, http://www.tylerpaper.com/article/20081120/NEWS08/811200292, and http://oilspot2.dtnenergy.com/e_article001272178.cfm?x=b11,0,w.

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