So … why do they not vent it themselves to avoid the big badda boom? Seems a nice controlled seep of gas though toxic is better than the boom. Hey, is it flammable? Do the sewer plant thing and turn it into a nice torch burning off the exudate. Set up a diversion pipe to another set of smaller tanks and use the main tank as a filling station to take the gas off to smaller tanks and get them out of the way. [sorry, ex hazmat at chemical factory, and YES I do know the issues of leaking industrial gasses into the open air, one still needs ott evacuate BUT no boom. Seems a fair deal to me]
It’s not a “massive” leak. The entire tank contents if liquid would form a puddle 1 foot deep in my 1-1/2 bedroom apartment.
The whole concern is the unpredictable direction the fumes will move once it leaks, bursts, or booms. If they could accurately predict the wind direction and release volume they might get away with evacuating a dozen houses across the street from the plant and leave it at that.
The problem is they can’t do that. So they have to evacuate everyone in every direction out to an implausible worst-case distance. Which turns out to be ~1-1/2 miles.
The article says the output valves of the tank are clogged. Presumably with solidifying / solidified reacted material. So no offloading.
It’s not clear about how the vents are faring. But yeah, anyone with any background in this stuff knows about venting and flaring to preclude a BLEVE. The fact they’re not doing it already suggests they think it can’t be done.
I don’t know anything about the idea of breaching the tank in a sorta controlled fashion. But it’s an interesting speculation.
There’s also the issue of responder safety. There are maybe a bunch of things they could do if they were willing to have a crew of plant workers and firefighters crawling around on & under the tank. But if they don’t want to risk anyone within e.g. 200 feet of the tank, what can they do with whatever remote controlled robotic gizmos they may have? I know I know nothing of this.
So far it sounds like the plan amounts to “spray water on it with remote hoses, and hope to keep the tank cool enough to hold together until the reaction runs out of reactants.”
And that may in fact be the best plan possible.
That is not how steel works. If it were, World Trade Centers One and Two would still be standing. Because the fires from the burning jet fuel would have made their steel beams stronger. But (as you may recall from debunking 9/11-truthers) they infamously made them weaker, to the point that even though they never reached melting temperatures, they were sufficiently weakened as to collapse under the weight of the floors above them, which in turn was a sufficient shock to cause a cascading collapse of the floors beneath them.
Plus, as I recall from my various courses on materials, the hardness, strength, and brittleness of steel tend to go down as temperature increases, while ductility and toughness (which is distinct from strength) tend to go up as temperature increases.
And I missed the edit window, but something else to consider: is there a temperature at which methyl methacrylate breaks down chemically, to the point it’s not that anymore, and may instead break down into its constituents gases? That’s not something I have studied, but I’d want to know that before being confident it would simply harden and contract.
ETA: Wikipedia indicates its boiling point is 214 degrees. Whether it also breaks down at that temperature or not, or whether the tank is at risk of reaching that temperature, I don’t know.
My error, I realized after I wrote that the tank here is probably stainless steel, and will be weaker when warm.
Structural steel, like the twin towers, is strongest around 200-300 C. At 50-100 C, as in this case, it is stronger than at room temperature. The Twin Towers kerosine fire burned at @ 1000 C. It’s not relevant to this emergency at present.
I edited the title to add the date and the “breaking news” indication.
Nobody is saying it but, the major concern is that Orange County (probably) has the highest number of lawyers per square mile than any residential area in the world. As soon as they get a whiff of that chemical in their own backyards, the resulting flood of lawsuits will make the Great Molasses Flood look like a leaky bathtub.
Moderating: this is the breaking news thread. Please stick to the event. If there are a bunch of lawsuits, you can post about it then. But this is not the place to make politically-adjacent snipes.
Thanks.
Latest update: the tank is beginning to heat up again and an additional 39,000 people have been ordered to evacuate.
“Unfortunately, I do have to report that the temperature was 90 degrees. Yesterday morning it was 77 degrees when we backed out. It’s been averaging about a degree an hour increasing, so that’s the bad news,” Covey said.
The discovery was made after emergency crews were put “in harm’s way” Friday night in an attempt to neutralize a second tank at the facility, Covey said.
The fire captain said officials are “unsure” about the precise temperature at which the tank could ignite or explode.
Sorry if I missed it, but has anyone answered this? If it was covered in the first cite, I didn’t see it.
What happened? Why is it overheating in the first place?
To be clear, it’s overheating because the reaction is exothermic. My question was, what started the the reaction?
That is not at all helpful to us dumb non-scientists. What reaction? What the hell is exothermic?
BTW, not looking to be educated in tremendous detail. A two-sentence layman’s explanation would do the trick. Again, sorry if this was covered and it’s just too over my head to even recognize.
Sorry. I am not a chemist, but I can help a little. The substance is turning from liquid to solid. Think of it like super glue drying (curing). The process gives off a lot of heat.
The great danger is that it also can turn to a gas, which is heavier than air. So if you were standing next to the tank when a bunch of this gas let off, you could suffocate just standing there breathing, because it would displace the normal gases that we breathe. A cloud of this would move along the ground and settle into low areas like basements and valleys. It would take careful monitoring to be sure that those areas were safe to breathe in. You could “drown” in it.
At lower concentrations (say if the wind were blowing lightly and mixing it with air) it could cause irritation that might kill an asthmatic, a baby, or someone with other health conditions, while just being painful to a strong healthy person.
And there are a LOT of unknowns because this just has never happened before.
Thanks. Do you happen to know, why did this take them by surprise? Is the chemical behaving in some unpredictable way?
To give you a sense of how little I know of such things, when I first saw the headline my reaction was “Why don’t they just turn the pilot off?” 
I understand they also believe it could cause fires to break out in other locations, though I don’t understand the science of that myself.
Apparently, the problem was discovered by a crew investigating a problem with another tank on the property. The story linked in the OP also states there are two other similar tanks of the same stuff adjacent to this one. If there is an explosion, it could potentially be 20K+ gallons of chemicals released; not 7000.
Found another article on the incident; apparently one of the main reasons they have so few options is that the valve to the tank is “gummed up”, so they can’t use the normal solution of adding a neutralizing agent to kill the reaction.
Apparently another reason for the unpredictability is that they have little ability to monitor what’s going inside the tank, and part of the reason the chemical inside is heating up so much is that’s it’s undergoing a potential runaway chemical reaction. Heat causes the reaction and heat, the excess heat causes more of the chemical to react and more heat, and so on.
Apparently the answer to that is a straightforward “huge fireball”.
“If you build too much heat or pressure, then you get the explosion. And the material is also highly flammable, in addition to being toxic, and so you can have, fumes of toxins, flames like literal fireballs, and the explosion itself,” Picazo said.
The worst-case scenario is an uncontrolled explosion. “If you’ve ever seen videos of tank cars on a railroad track blowing up, and that fireball it puts out, and it blows half the tank car a half a mile down the train track, that’s the incident potential we are dealing with if this suffers a catastrophic failure,” Covey said.
A “reaction” is a process in which a substance changes its physical state (like from solid to liquid) or forms new products that are different than what you started out with (called the reactants). The former is a physical reaction. The latter is a chemical reaction (if chemical bonds are broken and/or reformed), or a nuclear reaction if nuclear forces are involved.
Some reactions give off heat, like combustion (i.e. burning). Reactions that give off heat are called exothermic reactions.
To go into more detail, for anyone who might be interested:
Methyl methacrylate is the monomer (small molecule) which is used to make the polymer (big molecule made of thousands of monomers) used to make acrylic. While the polymer forms, thousands and thousands of monomers make chemical bonds to form the polymer. This process nearly always releases heat (is exothermic). This leads to a runaway cycle where the heat increases the reaction rate, which increases the temperature, which increases the reaction rate, and so on. The temperature goes up exponentially until it either boils away or burns all the material (preferred) or builds up pressure in the tank, causing it to explode (bad). Those explosions are hard to predict, but can reach kiloton scales.
This holding tank should have been cooled below the temperature at which the reaction occurs spontaneously, and should have had multiple fail-safes to prevent this, usually something like multiple monitoring systems and several methods of cooling, or even a way to add some another chemical that poisons the reaction. Likely this was some combination of negligence, bad luck, and multiple system failures.