Why can’t they drill it and pipe it off into some drainage pipe for cooling or collecting in trucks?
Divide and conquer
Divide and conquer
Flash point 2 °C (36 °F; 275 K) Autoignition temperature 435 °C (815 °F; 708 K) Explosive limits 1.7%-8.2%
Drilling is too risky then. What about dumping liquid nitrogen on the thing until it’s doused?
Besides, tanks like these have various portholes, valves and drains already. The article mentions an "inoperable valve" so maybe that's the problem but I'd be surprised if there were just one. They must have been getting the contents out of the tank and into the manufacturing process somehow.
(Because, I mean: If this thing is as sketchy as it is made out to be, then nobody is just walking over there with a spanner to loosen a cover. There aren't enough dollars nor PPE available to make this happen.)
That being said, in no way, shape or form am I an authority on the subject.
Which, of course, is pretty spark resistant to begin with.
Even if this wasn't true, this is not a hard problem, you can use non-sparking tools, proper coolant, lots of things to avoid sparks.
Or you know, we could require that highly flammable materials subject to thermal runaway have "drill here in case of emergency" patch of non-sparking material or something.
The cost of ATEX/Class 1 Div 1 compliance would not really go up if you required this.
If I recall correctly, high pressure ignitable stuff can spontaneously turn !!FUN!! in absence of heat if it is suddenly relieved through a pinhole. Basically jet is followed by a ring-like zone where the stuff mixes with oxygen. Jet creates tiny zones of very high temp, thus igniting the mixture ring that follows.
It also has a fairly small explosive concentration range (2-12%).
(the inhibitors it gets mixed with are about the same autoignition temperature, but have higher flashpoints).
In any case:
1. The pinhole issue can be resolved pretty easily by making a big hole instead of a small one :)
2. MMA is normally stored at ~0psi. The increasing pressure here is from runaway polymerization boiling the liquid (the runaway comes from the polymerization being strongly exothermic). These tanks are not built to handle very much pressure, usually a few psi max. I doubt whatever the tank pressure is currently qualifies as the kind of high pressure you are talking about.
3. There is apparently a significant crack now that is relieving most of the pressure. Which is preventing it from bursting. Assuming the crack didn't exist before this all occurred (so far the prevailing theory is it did not, but who knows how it will turn out), it almost certainly started as a pinhole that propagated, so if it was going to ignite the way you said, it would have happened already. My guess - even if what you say is 100% correct, the pressure is never high enough to cause issues, even with pinholes.