Posted on 04/21/2013 11:22:36 AM PDT by OKRA2012
The West, Texas fertilizer plant where a powerful explosion killed at least 14 and injured dozens on Wednesday failed to disclose a massive ammount of ammonium nitrate ordinarily regulated by federal officials, according to Reuters.
The U.S. Department of Homeland Security requires fertilizer plants and depots to disclose amounts of ammonium nitrate, which can be used to make a bomb, above 400 lbs. The West, Texas plant, West Fertilizer, reportedly held 270 tons of the substance, 1,350 times that limit.
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I remember seeing those charts at a military ammo dump. Some of the circles for the safe distance went out 20-30km.
That was with berms but it wasn’t ammonium nitrate. :)
The equivalent is about 63,000 gal of gasoline, and most decent sized gas stations have between 60-120,000 gallons in storage.
Even if it were just over 10,000 gallons, the implied safety standoff distance in the event of a catastrophic failure would exceed 1000ft.
This implies no more gas stations off the interstate highways, unless they are a couple of blocks away from the road.
Think about that the next time you’re driving down the highway and see a gas station.
A berm really doesn’t work. The overpressure will still get those within the safety arcs if calculating the plot plan as an ammunition depot.
Same applies if you are driving by a tractor trailer hauling gasoline.
Then don’t build your house near a fertilizer plant.
Berms built to about 15 ft high with a wide base would certainly mitigate the damage and causalities.
100 ft? This thing leveled everything out for a couple thousand feet. At onepoint the sheriff said a 5 mile wide area of destruction
I ran preliminary design calcs to meet explosive codes/requirements about 10 years ago and they had to be something like 20-35 ft tall. That was only for a safehaven for a tractor trailer, granted it was on a slope which exasperated the problem.
Current ATFP stds require something like twice the Bldg height, then in profile a distance beyond which the shock wave doesn’t drop in elevation to any occupied structure.
Atd Bldg height with max 12ft story is probably about 15’ (maybe higher). Probably looking at something around the 30s to 40s to begin that approach.
FWIW, the codes generally approach the topic by first addressing the risk. Statistics and percentages.
Then they look at risk reduction factors.
1st line of defense probably should be fire protection and fire alarm.
It usually takes a fair amount of time for an ammonium nitrate storage to detonate,...I believe this fire beganin the morning, was thought to have been put out, then discovered to be smoldering again, then worked again with windy conditions.
Great Texas City Explosion was similar. Fire was believed to have been put out but the fertilizer smoldered. Ship Captain sealed the compartment believing lack of air would snuff out the fire, but in that chemical fire, the reaction continued.
IMHO, instead of chasing after codes, insisting more regulations be made and the public and businesses further yoked, first look at more reasonable methods of prevention.
What started the fire?
Why did it spread to the vicinity?
Why wasn’t it immediately extinguished?
Why weren’t there sirens and public alert systems in place?
The people in the business likely know the business much better than you, myself, and definitely a set of codes, which nobody can afford anyways. Keep it simple and locally controllable.
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