Why wouldn't there be passive protection systems designed in?
After a big earthquake you don't want to have to also deal with other emergencies (à la Fukushima).
Aside: One good side-effect of the 2011 Tōhoku earthquake being so horrific is that it stopped the self-obsessed whinging in my city (Christchurch was still trying to recover from an earthquake).
Why? For the same reason our reactors do not have containment buildings around them, like those in the West. For the same reason we don't use properly enriched fuel in our cores. For the same reason we are the only nation that builds water-cooled, graphite-moderated reactors with a positive void coefficient.
By the miraculous grace of God, a crack allowed pressure to bleed & enabled our engine company to prevent thermal runaway. A BLEVE was the projected outcome, a firefighters worst nightmare - see the Kingman BLEVE - https://www.cityofkingman.gov/government/departments-a-h/fir...
I had wondered the whole time why they didn’t just pierce it with an AM rifle. Would that not have been better than a random partial failure via a crack?
Genuinely open question. I don’t know anything about stuff.
> The immediate danger seems to abated, fortunately,
The "it will explode leveling a couple city blocks" danger seems to be abated, but instead it's spraying an insanely toxic chemical out into the open, which will likely have health repercussions for residents for decades?
Thousands of gallons of toxic chemicals don't just disappear.
What a disaster and complete failure on the local government in the way they handled this situation. If we ever get hit by an earthquake or other larger disaster, it's safe to assume we're all on our own.
Also, as someone affected by this, it has been extremely frustrating getting updates via xitter. Do we really have no other options?
Now I'm thinking that a weak part of the tank gave way at one of the lesser welds on this non-pressure vessel, quite early and in the top part of the tank well above the liquid level. When you stand on top of a big tank, a lot of them do flex quite a bit. Physical pressure must have increased somehow in a way that could not be relieved without rupture.
IIRC there was some report of a "gas leak" to begin with and that could very well have been it.
I can only imagine what it's like to be one of the shift operators down there on the pavement around the tanks and pipes on a daily basis, in their flame-retardant coveralls and hardhats. Based on my vivid experience working with similar operators as I took official samples from tanks usually located in much bigger tank farms.
MMA smells so sharp that any leakage from a valve or pipe fitting gets attention much more so than other flammable liquids, for instance things like paint removers, alcohol or acetone which smell very faint by comparison. I expect that the workers had gotten accustomed to a fairly clean air environment without serious toxicity levels, and would estimate that a leak of about 1 drop per minute from a flange would be easily identified and fixed. Not only to keep the neighbors from complaining, but to keep the workers from gagging when they walk closer to that location.
If the first sign of trouble was physical tank bulging and/or suddenly stinking up the whole place with lots of MMA vapor (like from an upper tank rupture) when there is no sign of leakage on the ground, that pretty much qualifies as a "gas leak". Once the smell was no longer prominent, I would say that polymerization was well underway and there was not as much free monomer available to build up more pressure or even evaporate very much after that. If there's warm liquid MMA open to the atmosphere, you will smell it downwind.
It might be a stretch to say that "nature takes its course" when synthetic monomers spontaneously polymerize like this, but that's what some of them do best that sets them apart.
From what I understand, in the uninhibited pure monomer it doesn't take that many PPM of monomer molecules to become "activated" in some way before the chain reaction of them with remaining molecules eventually accelerates to completion. Which may be why such a low concentration of inhibitor works so well, but inhibitor must be well-dispersed within the liquid and there must be enough circulation to avoid local depletion of the inhibitor due to stagnant contact with as yet unidentified unexpected initiators. Not only should it be easy to get a random 1 liter sample from a tank (of such non-viscous material) at any time, the single sample should ideally be highly representative of the entire tank contents. Due to the way the liquid is handled in bulk going in & out of the tank, as well as any additional circulation to insure good mixing of incoming cargo, or after boosting inhibitor amounts when only a few carefully measured pounds or kilos of the concentrated inhibitor is dumped into the bulk monomer to keep it from going below spec.
The inhibitors have been selected to be very strong and effective at what they do so it doesn't require a high concentration, and the downstream processors can more easily overcome the inhibitor effect and produce plastics using different and milder polymerization initiator techniques when there is not an excess of inhibitor.
Once it gets polymerizing past that minuscule little inhibitor, from that point it's like there is no inhibitor at all. So there is some possibility that this is a fairly worst-case runaway polymerization event where the full amount of caution was rightfully warranted. Even though it would have to be considered fairly benign compared to a whole tank of the liquid monomer dispersing through the neighborhoods, or going up in a fireball, which is always a risk anyway :\
Under storage, it really is tremendous force that t...
Reminder that the US Chemical Safety Board does great investigations into these kinds of accidents. Here’s a famous one from 2007 involving methylcyclopentadienyl manganese tricarbonyl (a gasoline additive) at T2 Laboratories in Jacksonville Florida. The CSB has a long record of producing great investigative videos without any partisan or legal bias, as the one shown here demonstrates:
This agency is the subject of a budget war between the current executive and Congress, with the former trying to cut its budget and the Congress just restoring its budget, so not sure if it will be doing a report on Garden Grove:
Tangent but there's a great Sublime song titled `Garden Grove`. Looks like they made a modern video for it that presumably shows a lot of Garden Grove. Or it could be Long Beach, I don't know. https://www.youtube.com/watch?v=qpSo_zj0UQw
> "I look forward to the eventual incident report for the root causes of this one - assuming that we do such things any more here in the #$%@! Golden Age in which we find ourselves - because that, too, will make things safer going forwards. One hopes."
If there's no after action report, we'll never get a good episode of Well There's Your Problem on this incident, and that would be a loss for both engineering and podcasting ;-(
(also waaaay down on the list of uses at https://en.wikipedia.org/wiki/Poly(methyl_methacrylate) but I thought that first link was clearer. Look for "In semiconductor research and industry, PMMA aids as a resist in the electron beam lithography process.")
Being an armchair expert, I wondered if they couldn't have flown a quadcopter with a small drilling machine and drill a hole on the top to relive pressure?
"It’s unlikely that firefighters would consider creating a hole in the tank because of fears that could create a spark that might ignite the volatile and flammable gas."
28 comments
[ 3.4 ms ] story [ 42.6 ms ] threadAfter a big earthquake you don't want to have to also deal with other emergencies (à la Fukushima).
Aside: One good side-effect of the 2011 Tōhoku earthquake being so horrific is that it stopped the self-obsessed whinging in my city (Christchurch was still trying to recover from an earthquake).
It's cheaper.
I was literally just this afternoon telling someone about TIWWW and posting them some favourites.
Genuinely open question. I don’t know anything about stuff.
The "it will explode leveling a couple city blocks" danger seems to be abated, but instead it's spraying an insanely toxic chemical out into the open, which will likely have health repercussions for residents for decades?
Thousands of gallons of toxic chemicals don't just disappear.
It’s toxic but not insanely toxic. Isocyanates, phosgene, gaseous cyanides - now those are insanely toxic
Also, as someone affected by this, it has been extremely frustrating getting updates via xitter. Do we really have no other options?
https://iomosaic.com/docs/default-source/papers/polymerizati...
From fuzzfactor's comment with lots of other great info:
https://news.ycombinator.com/item?id=48252245
IIRC there was some report of a "gas leak" to begin with and that could very well have been it.
I can only imagine what it's like to be one of the shift operators down there on the pavement around the tanks and pipes on a daily basis, in their flame-retardant coveralls and hardhats. Based on my vivid experience working with similar operators as I took official samples from tanks usually located in much bigger tank farms.
MMA smells so sharp that any leakage from a valve or pipe fitting gets attention much more so than other flammable liquids, for instance things like paint removers, alcohol or acetone which smell very faint by comparison. I expect that the workers had gotten accustomed to a fairly clean air environment without serious toxicity levels, and would estimate that a leak of about 1 drop per minute from a flange would be easily identified and fixed. Not only to keep the neighbors from complaining, but to keep the workers from gagging when they walk closer to that location.
If the first sign of trouble was physical tank bulging and/or suddenly stinking up the whole place with lots of MMA vapor (like from an upper tank rupture) when there is no sign of leakage on the ground, that pretty much qualifies as a "gas leak". Once the smell was no longer prominent, I would say that polymerization was well underway and there was not as much free monomer available to build up more pressure or even evaporate very much after that. If there's warm liquid MMA open to the atmosphere, you will smell it downwind.
It might be a stretch to say that "nature takes its course" when synthetic monomers spontaneously polymerize like this, but that's what some of them do best that sets them apart.
From what I understand, in the uninhibited pure monomer it doesn't take that many PPM of monomer molecules to become "activated" in some way before the chain reaction of them with remaining molecules eventually accelerates to completion. Which may be why such a low concentration of inhibitor works so well, but inhibitor must be well-dispersed within the liquid and there must be enough circulation to avoid local depletion of the inhibitor due to stagnant contact with as yet unidentified unexpected initiators. Not only should it be easy to get a random 1 liter sample from a tank (of such non-viscous material) at any time, the single sample should ideally be highly representative of the entire tank contents. Due to the way the liquid is handled in bulk going in & out of the tank, as well as any additional circulation to insure good mixing of incoming cargo, or after boosting inhibitor amounts when only a few carefully measured pounds or kilos of the concentrated inhibitor is dumped into the bulk monomer to keep it from going below spec.
The inhibitors have been selected to be very strong and effective at what they do so it doesn't require a high concentration, and the downstream processors can more easily overcome the inhibitor effect and produce plastics using different and milder polymerization initiator techniques when there is not an excess of inhibitor.
Once it gets polymerizing past that minuscule little inhibitor, from that point it's like there is no inhibitor at all. So there is some possibility that this is a fairly worst-case runaway polymerization event where the full amount of caution was rightfully warranted. Even though it would have to be considered fairly benign compared to a whole tank of the liquid monomer dispersing through the neighborhoods, or going up in a fireball, which is always a risk anyway :\
Under storage, it really is tremendous force that t...
https://www.csb.gov/t2-laboratories-inc-reactive-chemical-ex...
This agency is the subject of a budget war between the current executive and Congress, with the former trying to cut its budget and the Congress just restoring its budget, so not sure if it will be doing a report on Garden Grove:
https://www.chemistryworld.com/news/congress-rescues-industr...
See also: https://news.ycombinator.com/item?id=46904017
If there's no after action report, we'll never get a good episode of Well There's Your Problem on this incident, and that would be a loss for both engineering and podcasting ;-(
(also waaaay down on the list of uses at https://en.wikipedia.org/wiki/Poly(methyl_methacrylate) but I thought that first link was clearer. Look for "In semiconductor research and industry, PMMA aids as a resist in the electron beam lithography process.")
Per https://apnews.com/article/california-chemical-tank-leak-c1f...